WEBVTT 00:00:00.000 --> 00:00:02.440 align:middle line:90% [SQUEAKING] 00:00:02.440 --> 00:00:04.380 align:middle line:90% [RUSTLING] 00:00:04.380 --> 00:00:08.260 align:middle line:90% [CLICKING] 00:00:08.260 --> 00:00:11.880 align:middle line:90% 00:00:11.880 --> 00:00:18.760 align:middle line:84% PROFESSOR: So the question before in this module 00:00:18.760 --> 00:00:24.680 align:middle line:84% is, is there really a linkage between nuclear power 00:00:24.680 --> 00:00:27.480 align:middle line:90% and nuclear proliferation? 00:00:27.480 --> 00:00:32.080 align:middle line:84% And it's inherently a question about the export 00:00:32.080 --> 00:00:33.720 align:middle line:90% of nuclear power. 00:00:33.720 --> 00:00:36.840 align:middle line:84% We're not worried that the United States might make a bomb 00:00:36.840 --> 00:00:40.000 align:middle line:90% from our civilian reactors. 00:00:40.000 --> 00:00:42.080 align:middle line:84% And most of the class has been focused 00:00:42.080 --> 00:00:47.880 align:middle line:84% on domestic policy and domestic economics for nuclear power 00:00:47.880 --> 00:00:49.320 align:middle line:90% here in the US. 00:00:49.320 --> 00:00:59.058 align:middle line:84% But it does relate to US policy towards nuclear power because 00:00:59.058 --> 00:00:59.850 align:middle line:90% of several reasons. 00:00:59.850 --> 00:01:02.225 align:middle line:84% One is we're interested in helping other countries reduce 00:01:02.225 --> 00:01:04.830 align:middle line:90% CO2. 00:01:04.830 --> 00:01:08.350 align:middle line:84% And nuclear power is actually a good technology 00:01:08.350 --> 00:01:11.270 align:middle line:84% for some countries that don't have access 00:01:11.270 --> 00:01:13.110 align:middle line:90% to cheap wind and solar. 00:01:13.110 --> 00:01:15.910 align:middle line:90% 00:01:15.910 --> 00:01:19.150 align:middle line:84% And second is that if people want 00:01:19.150 --> 00:01:22.750 align:middle line:84% to support a nuclear industry in the United States 00:01:22.750 --> 00:01:24.750 align:middle line:84% and the economics of nuclear power 00:01:24.750 --> 00:01:27.450 align:middle line:84% remain as they are today, which is to say, 00:01:27.450 --> 00:01:30.350 align:middle line:84% not competitive with wind and solar, 00:01:30.350 --> 00:01:36.030 align:middle line:84% then the export industry is the principal market 00:01:36.030 --> 00:01:37.750 align:middle line:90% for nuclear power. 00:01:37.750 --> 00:01:43.870 align:middle line:84% And so we then need to give some consideration to this question 00:01:43.870 --> 00:01:48.550 align:middle line:84% if export is really the lifeline for the US nuclear industry. 00:01:48.550 --> 00:01:52.330 align:middle line:84% So how do we think productively about this intersection? 00:01:52.330 --> 00:01:54.990 align:middle line:90% 00:01:54.990 --> 00:01:58.880 align:middle line:84% How do we choose certain technologies to invest in? 00:01:58.880 --> 00:02:02.220 align:middle line:84% How do we make sure that whatever we're exporting 00:02:02.220 --> 00:02:05.940 align:middle line:84% isn't making the proliferation problem worse? 00:02:05.940 --> 00:02:10.780 align:middle line:84% So maybe we should say, well, why does this issue really 00:02:10.780 --> 00:02:11.680 align:middle line:90% arise at all? 00:02:11.680 --> 00:02:15.100 align:middle line:84% And maybe most of you know this, but maybe some of you don't. 00:02:15.100 --> 00:02:19.220 align:middle line:84% The issue is basically that the equipment and the materials 00:02:19.220 --> 00:02:24.580 align:middle line:84% in the nuclear fuel cycle can be repurposed 00:02:24.580 --> 00:02:26.200 align:middle line:90% for making nuclear weapons. 00:02:26.200 --> 00:02:32.340 align:middle line:84% Now, just because there is some technical connection 00:02:32.340 --> 00:02:37.700 align:middle line:84% doesn't mean that nuclear power causes proliferation. 00:02:37.700 --> 00:02:40.420 align:middle line:84% Proliferation is a process that entails 00:02:40.420 --> 00:02:45.940 align:middle line:84% both a political decision and technical programs. 00:02:45.940 --> 00:02:49.480 align:middle line:84% So it's not surprising that there is, however, 00:02:49.480 --> 00:02:52.040 align:middle line:84% an intersection of these two things, 00:02:52.040 --> 00:02:56.370 align:middle line:84% the technical feasibility for making nuclear weapons 00:02:56.370 --> 00:02:59.450 align:middle line:84% affects the political decision to decide 00:02:59.450 --> 00:03:02.010 align:middle line:90% to pursue nuclear weapons. 00:03:02.010 --> 00:03:06.130 align:middle line:84% So if you believe that your country just 00:03:06.130 --> 00:03:09.370 align:middle line:84% would have to develop all this technology itself, 00:03:09.370 --> 00:03:12.270 align:middle line:84% your decision to pursue nuclear weapons may not even come up. 00:03:12.270 --> 00:03:14.050 align:middle line:90% You may not consider it. 00:03:14.050 --> 00:03:17.450 align:middle line:84% If, however, you have all the technology at hand, 00:03:17.450 --> 00:03:22.850 align:middle line:84% you might decide if there's a security crisis, 00:03:22.850 --> 00:03:25.850 align:middle line:84% maybe we should be using some of this nuclear stuff 00:03:25.850 --> 00:03:29.330 align:middle line:90% and build a bomb. 00:03:29.330 --> 00:03:31.030 align:middle line:90% And there's evidence for this. 00:03:31.030 --> 00:03:36.330 align:middle line:84% So Iraq, Libya, and Iran are all countries that 00:03:36.330 --> 00:03:38.330 align:middle line:90% had nuclear weapons programs. 00:03:38.330 --> 00:03:40.250 align:middle line:84% And all of those nuclear weapons programs 00:03:40.250 --> 00:03:44.330 align:middle line:84% started after they had been offered nuclear technology 00:03:44.330 --> 00:03:47.930 align:middle line:90% on the black market. 00:03:47.930 --> 00:03:50.890 align:middle line:84% They probably, I would contend, never have thought that they 00:03:50.890 --> 00:03:54.500 align:middle line:84% could have done it, except once someone came to them-- 00:03:54.500 --> 00:03:56.640 align:middle line:90% in this case, AQ Khan-- 00:03:56.640 --> 00:03:59.760 align:middle line:84% said, would you like to buy these gas centrifuges? 00:03:59.760 --> 00:04:03.200 align:middle line:84% Then they're like, oh, we could do this, 00:04:03.200 --> 00:04:08.360 align:middle line:84% and we would have the ability to defend ourselves. 00:04:08.360 --> 00:04:10.840 align:middle line:84% So the political science professor, Matt Fuhrman, 00:04:10.840 --> 00:04:14.000 align:middle line:84% decided to do a big regression, and he 00:04:14.000 --> 00:04:18.160 align:middle line:84% regressed over all the civilian nuclear assistance 00:04:18.160 --> 00:04:22.240 align:middle line:84% agreements assigned between 1945 and the year 2000. 00:04:22.240 --> 00:04:24.920 align:middle line:84% And you may be surprised that there 00:04:24.920 --> 00:04:29.480 align:middle line:84% are thousands of these agreements between countries 00:04:29.480 --> 00:04:32.180 align:middle line:90% between that time period. 00:04:32.180 --> 00:04:36.160 align:middle line:84% And during that time, there are 15 countries 00:04:36.160 --> 00:04:42.480 align:middle line:84% that initiated nuclear weapons programs and a small handful 00:04:42.480 --> 00:04:48.080 align:middle line:84% that were finally successful, nine depending on how you count. 00:04:48.080 --> 00:04:51.110 align:middle line:90% And so what did he find? 00:04:51.110 --> 00:04:58.510 align:middle line:84% He found that, in fact, there are three factors that really 00:04:58.510 --> 00:05:04.990 align:middle line:84% correlate or predict whether a country will acquire 00:05:04.990 --> 00:05:06.990 align:middle line:84% nuclear weapons-- a slightly different result 00:05:06.990 --> 00:05:10.070 align:middle line:84% for start a nuclear weapons program. 00:05:10.070 --> 00:05:14.990 align:middle line:84% And those that are significant to the 1% level 00:05:14.990 --> 00:05:17.310 align:middle line:90% have three asterisks. 00:05:17.310 --> 00:05:18.830 align:middle line:84% And you see the biggest predictors 00:05:18.830 --> 00:05:22.710 align:middle line:84% are have peaceful nuclear cooperation, have 00:05:22.710 --> 00:05:27.870 align:middle line:84% a militarized dispute, and GDP per capita. 00:05:27.870 --> 00:05:29.050 align:middle line:90% So these are correlates. 00:05:29.050 --> 00:05:30.630 align:middle line:90% That's all they are. 00:05:30.630 --> 00:05:32.470 align:middle line:90% But it kind of makes sense. 00:05:32.470 --> 00:05:34.070 align:middle line:84% The richest countries in the world 00:05:34.070 --> 00:05:36.850 align:middle line:84% decide that we're the leading countries. 00:05:36.850 --> 00:05:39.190 align:middle line:84% We ought to have nuclear weapons-- 00:05:39.190 --> 00:05:41.310 align:middle line:90% not to be surprised. 00:05:41.310 --> 00:05:44.190 align:middle line:84% Having militarized dispute-- that makes sense. 00:05:44.190 --> 00:05:47.370 align:middle line:84% But the evidence also suggests that, yeah, 00:05:47.370 --> 00:05:52.640 align:middle line:84% it also matters that you have peaceful nuclear cooperation. 00:05:52.640 --> 00:05:55.700 align:middle line:90% 00:05:55.700 --> 00:05:57.340 align:middle line:84% So that does not necessarily mean 00:05:57.340 --> 00:05:59.960 align:middle line:84% that giving a state nuclear power will cause proliferation, 00:05:59.960 --> 00:06:02.180 align:middle line:84% but it does mean that we are increasing 00:06:02.180 --> 00:06:07.540 align:middle line:84% the probability in the future that some event might 00:06:07.540 --> 00:06:10.580 align:middle line:90% lead them to pursue weapons. 00:06:10.580 --> 00:06:12.420 align:middle line:84% Now, those charged with preventing 00:06:12.420 --> 00:06:18.300 align:middle line:84% this political decision will emphasize this role 00:06:18.300 --> 00:06:22.060 align:middle line:84% that technology seems to have, whereas those who are advocates 00:06:22.060 --> 00:06:24.700 align:middle line:84% of nuclear power will look at this 00:06:24.700 --> 00:06:28.760 align:middle line:84% and say, well, there are other factors that matter. 00:06:28.760 --> 00:06:30.980 align:middle line:84% We just should deal with these other factors 00:06:30.980 --> 00:06:35.580 align:middle line:84% and not worry about the small effect 00:06:35.580 --> 00:06:38.740 align:middle line:84% that having peaceful nuclear cooperation might have. 00:06:38.740 --> 00:06:39.720 align:middle line:90% Yeah? 00:06:39.720 --> 00:06:41.180 align:middle line:90% AUDIENCE: [INAUDIBLE] 00:06:41.180 --> 00:06:43.940 align:middle line:84% PROFESSOR: So the coefficients are the-- this 00:06:43.940 --> 00:06:45.900 align:middle line:90% is a probit regression. 00:06:45.900 --> 00:06:52.650 align:middle line:84% So I believe this is the number of standard deviations increased 00:06:52.650 --> 00:06:56.330 align:middle line:90% given the underlying model. 00:06:56.330 --> 00:06:58.390 align:middle line:84% It's pretty small effect, I would say, 00:06:58.390 --> 00:07:00.810 align:middle line:84% but I have to go back and double check that. 00:07:00.810 --> 00:07:04.350 align:middle line:84% I believe the result-- this is for, I believe, acquisition. 00:07:04.350 --> 00:07:08.650 align:middle line:84% And I believe the result for starting 00:07:08.650 --> 00:07:13.750 align:middle line:84% a program is a factor of 5, if my memory is correct. 00:07:13.750 --> 00:07:17.210 align:middle line:84% So you're five times more likely to start a nuclear weapons 00:07:17.210 --> 00:07:21.170 align:middle line:84% program if you have civil technology than if you don't. 00:07:21.170 --> 00:07:23.970 align:middle line:84% But the number of those programs that actually succeed 00:07:23.970 --> 00:07:26.390 align:middle line:84% to acquiring a weapon is actually small 00:07:26.390 --> 00:07:29.570 align:middle line:84% because we have a big nonproliferation effort. 00:07:29.570 --> 00:07:32.610 align:middle line:84% And we'll talk about the cost of maintaining 00:07:32.610 --> 00:07:35.210 align:middle line:84% that nonproliferation effort as kind 00:07:35.210 --> 00:07:40.210 align:middle line:84% of an externality on the cost of nuclear power. 00:07:40.210 --> 00:07:44.730 align:middle line:84% So what I'd like to try to do is pull this apart for us 00:07:44.730 --> 00:07:48.840 align:middle line:84% and see if we can have a better understanding of how this comes 00:07:48.840 --> 00:07:51.800 align:middle line:84% about and to give you the data to make 00:07:51.800 --> 00:07:55.680 align:middle line:84% your own judgment about whether the proliferation risk is 00:07:55.680 --> 00:08:00.120 align:middle line:84% a real risk or not really a significant risk. 00:08:00.120 --> 00:08:03.220 align:middle line:90% Disco lights over here. 00:08:03.220 --> 00:08:07.040 align:middle line:84% So let's do a thought experiment. 00:08:07.040 --> 00:08:11.120 align:middle line:84% Let's say you're a country that sees itself as a rising 00:08:11.120 --> 00:08:13.000 align:middle line:90% power on the world stage. 00:08:13.000 --> 00:08:14.760 align:middle line:84% And you can imagine a lot of countries 00:08:14.760 --> 00:08:17.240 align:middle line:90% might have that self-perception. 00:08:17.240 --> 00:08:19.840 align:middle line:84% Maybe you're already a regional power, 00:08:19.840 --> 00:08:22.060 align:middle line:84% and maybe you have some regional adversaries, 00:08:22.060 --> 00:08:23.560 align:middle line:84% and maybe some of those adversaries 00:08:23.560 --> 00:08:29.280 align:middle line:84% have nuclear ambitions, or maybe they even have nuclear weapons. 00:08:29.280 --> 00:08:34.080 align:middle line:84% And the example I want to give is Saudi Arabia-- 00:08:34.080 --> 00:08:38.000 align:middle line:84% a very large country, a very wealthy country. 00:08:38.000 --> 00:08:44.030 align:middle line:84% It has adversaries in the form of Israel and Iran. 00:08:44.030 --> 00:08:46.310 align:middle line:90% And both of those-- 00:08:46.310 --> 00:08:48.950 align:middle line:84% Israel has nuclear weapons, and Iran 00:08:48.950 --> 00:08:50.930 align:middle line:84% has had a nuclear weapons program 00:08:50.930 --> 00:08:53.310 align:middle line:84% and potentially could make nuclear weapons. 00:08:53.310 --> 00:08:57.670 align:middle line:90% It has an ally in Pakistan. 00:08:57.670 --> 00:09:01.910 align:middle line:84% Pakistan and Saudi are kind of political sister countries. 00:09:01.910 --> 00:09:06.403 align:middle line:90% And they have nuclear weapons. 00:09:06.403 --> 00:09:08.070 align:middle line:84% And so if you're Saudi Arabia and you're 00:09:08.070 --> 00:09:09.653 align:middle line:84% like, my enemies have nuclear weapons, 00:09:09.653 --> 00:09:11.990 align:middle line:84% my friends have nuclear weapons, why 00:09:11.990 --> 00:09:13.290 align:middle line:90% don't I have nuclear weapons? 00:09:13.290 --> 00:09:15.350 align:middle line:90% I'm a very rich country. 00:09:15.350 --> 00:09:19.670 align:middle line:90% I should have these things too. 00:09:19.670 --> 00:09:24.150 align:middle line:84% So imagine this is the motivation. 00:09:24.150 --> 00:09:28.230 align:middle line:84% And what steps would Saudi have to take? 00:09:28.230 --> 00:09:31.630 align:middle line:84% Well, first, it would have to decide 00:09:31.630 --> 00:09:34.510 align:middle line:84% what kind of nuclear weapon it wanted to build. 00:09:34.510 --> 00:09:38.710 align:middle line:84% So there are two principal types that we talk about. 00:09:38.710 --> 00:09:42.840 align:middle line:84% One is gun type, and one is implosion type. 00:09:42.840 --> 00:09:43.840 align:middle line:90% So this is the gun type. 00:09:43.840 --> 00:09:46.420 align:middle line:84% This is an illustration of the Hiroshima bomb. 00:09:46.420 --> 00:09:51.660 align:middle line:84% And the idea is that you have two chunks of fissile material, 00:09:51.660 --> 00:09:55.060 align:middle line:84% almost always highly enriched uranium, though you 00:09:55.060 --> 00:09:58.940 align:middle line:84% could, in principle, do this with uranium-233. 00:09:58.940 --> 00:10:04.540 align:middle line:84% And you shoot one down a tube into the other, 00:10:04.540 --> 00:10:07.380 align:middle line:90% and you get a nuclear explosion. 00:10:07.380 --> 00:10:10.180 align:middle line:90% It's extremely simple to make. 00:10:10.180 --> 00:10:12.180 align:middle line:84% The design of the Hiroshima weapon 00:10:12.180 --> 00:10:15.600 align:middle line:84% was so simple that we actually never bothered to test it. 00:10:15.600 --> 00:10:17.260 align:middle line:84% We just dropped the bomb on Hiroshima 00:10:17.260 --> 00:10:21.860 align:middle line:84% because there's just no way this thing was not going to work. 00:10:21.860 --> 00:10:26.060 align:middle line:84% All of South Africa's nuclear weapons were gun type weapons. 00:10:26.060 --> 00:10:28.560 align:middle line:84% You don't need any really advanced engineering. 00:10:28.560 --> 00:10:32.220 align:middle line:84% You don't need to know any hydrodynamics. 00:10:32.220 --> 00:10:34.540 align:middle line:84% You don't need fancy equations of state. 00:10:34.540 --> 00:10:37.060 align:middle line:90% It's a very low-risk design. 00:10:37.060 --> 00:10:40.190 align:middle line:84% People even talked about there's a substantial risk. 00:10:40.190 --> 00:10:42.410 align:middle line:84% If someone puts a chunk of highly-enriched uranium 00:10:42.410 --> 00:10:44.250 align:middle line:84% on the ground and stands on a ladder 00:10:44.250 --> 00:10:46.450 align:middle line:84% and drops another chunk on top of it, 00:10:46.450 --> 00:10:50.570 align:middle line:84% you will also get a nuclear explosion. 00:10:50.570 --> 00:10:54.450 align:middle line:90% It's really that simple to make. 00:10:54.450 --> 00:10:58.050 align:middle line:84% What you need, though, is the highly-enriched uranium. 00:10:58.050 --> 00:11:01.850 align:middle line:84% And traditionally, so highly-enriched uranium is 00:11:01.850 --> 00:11:04.690 align:middle line:84% defined as uranium enriched to more than-- 00:11:04.690 --> 00:11:10.290 align:middle line:84% just by definition enriched to more than 20%. 00:11:10.290 --> 00:11:14.890 align:middle line:84% The Hiroshima bomb used an average enrichment 00:11:14.890 --> 00:11:18.570 align:middle line:90% somewhere around 80%. 00:11:18.570 --> 00:11:20.750 align:middle line:84% Nowadays, if we were to build weapons, 00:11:20.750 --> 00:11:23.610 align:middle line:84% we would choose something like 93% or something 00:11:23.610 --> 00:11:26.170 align:middle line:90% like this because we can. 00:11:26.170 --> 00:11:28.970 align:middle line:90% It just makes it easier. 00:11:28.970 --> 00:11:31.090 align:middle line:90% Getting this is the hard part. 00:11:31.090 --> 00:11:35.090 align:middle line:84% And one of the readings talks about whether, 00:11:35.090 --> 00:11:39.560 align:middle line:84% if we go to halo fuels that are right at 19.75 weight 00:11:39.560 --> 00:11:45.520 align:middle line:84% percent, which is 19.9 atom percent, 00:11:45.520 --> 00:11:49.580 align:middle line:84% will this actually be adequate for nuclear weapons? 00:11:49.580 --> 00:11:52.720 align:middle line:90% And there is some evidence-- 00:11:52.720 --> 00:11:54.900 align:middle line:84% actually, we should say substantial evidence, 00:11:54.900 --> 00:11:57.340 align:middle line:84% including testimony from US weapons designers, 00:11:57.340 --> 00:12:01.440 align:middle line:84% that, yes, you could make a weapon from 20%. 00:12:01.440 --> 00:12:07.080 align:middle line:84% So this is one of the concerns is that you would-- even 00:12:07.080 --> 00:12:09.040 align:middle line:84% though it's technically below the threshold 00:12:09.040 --> 00:12:12.440 align:middle line:84% of highly-enriched uranium, from a statutory perspective, 00:12:12.440 --> 00:12:17.560 align:middle line:84% if we export reactors that have large quantities of this stuff, 00:12:17.560 --> 00:12:20.920 align:middle line:84% we might be making this problem worse. 00:12:20.920 --> 00:12:24.100 align:middle line:90% Anyway, why does it work? 00:12:24.100 --> 00:12:27.640 align:middle line:84% Basically, remember that criticality 00:12:27.640 --> 00:12:29.580 align:middle line:90% is a geometric phenomenon. 00:12:29.580 --> 00:12:36.590 align:middle line:84% And as you have small chunks, the mean-free path can be large 00:12:36.590 --> 00:12:38.290 align:middle line:84% compared to the size of the chunk, 00:12:38.290 --> 00:12:40.390 align:middle line:84% but if we just put two chunks together, 00:12:40.390 --> 00:12:43.270 align:middle line:84% then the mean-free path will be smaller 00:12:43.270 --> 00:12:44.450 align:middle line:90% than the size of the chunk. 00:12:44.450 --> 00:12:46.412 align:middle line:84% And so then, on average, more than one neutron 00:12:46.412 --> 00:12:47.870 align:middle line:84% will stay in the volume, and you'll 00:12:47.870 --> 00:12:50.150 align:middle line:90% get a runaway chain reaction. 00:12:50.150 --> 00:12:53.350 align:middle line:84% That's basically the whole scheme. 00:12:53.350 --> 00:12:59.630 align:middle line:84% To make a nuclear-sized explosion, you need about 2 00:12:59.630 --> 00:13:03.870 align:middle line:84% to the 8-- you need about 80 generations, so about 2 00:13:03.870 --> 00:13:05.770 align:middle line:90% to the 80 fissions. 00:13:05.770 --> 00:13:07.870 align:middle line:84% And you can just do the calculation. 00:13:07.870 --> 00:13:12.010 align:middle line:84% 2 to the 80 fissions times however much energy-- 00:13:12.010 --> 00:13:13.930 align:middle line:84% I forget what is the immediate release. 00:13:13.930 --> 00:13:17.490 align:middle line:90% Is it 180 MeV-- 00:13:17.490 --> 00:13:19.470 align:middle line:84% it's 200 MeV per fission, but that's 00:13:19.470 --> 00:13:26.850 align:middle line:84% if you include the energy from delayed decay of stuff. 00:13:26.850 --> 00:13:32.990 align:middle line:84% So I think it's 180 or ish MeV for the prompt energy release. 00:13:32.990 --> 00:13:38.380 align:middle line:84% And so 2 to the 80 of those, and you have a bomb. 00:13:38.380 --> 00:13:42.540 align:middle line:84% Now, all of that, the only reason that is explosive 00:13:42.540 --> 00:13:46.060 align:middle line:84% is because all of this happens in 1 microsecond. 00:13:46.060 --> 00:13:50.660 align:middle line:84% 80 generations-- the average time between one of these events 00:13:50.660 --> 00:13:54.340 align:middle line:90% is about 10 nanoseconds. 00:13:54.340 --> 00:13:55.800 align:middle line:90% That actually has a unit. 00:13:55.800 --> 00:13:58.620 align:middle line:84% Does anyone know what the name of the unit is? 00:13:58.620 --> 00:14:00.000 align:middle line:90% I'm sure someone knows here. 00:14:00.000 --> 00:14:03.380 align:middle line:90% 00:14:03.380 --> 00:14:05.200 align:middle line:90% One shake is 10 nanoseconds. 00:14:05.200 --> 00:14:07.540 align:middle line:84% That's the fast fission time constant. 00:14:07.540 --> 00:14:12.140 align:middle line:84% These are the cross section is a barn because as big as a barn, 00:14:12.140 --> 00:14:15.055 align:middle line:84% and the time scale is a shake because it's 00:14:15.055 --> 00:14:16.680 align:middle line:84% as short as the shake of a lamb's tail. 00:14:16.680 --> 00:14:20.060 align:middle line:90% They all come from farm things. 00:14:20.060 --> 00:14:23.380 align:middle line:90% There are other farm ones also. 00:14:23.380 --> 00:14:26.780 align:middle line:84% It's all because the place where we had developed nuclear weapons 00:14:26.780 --> 00:14:30.900 align:middle line:84% was Los Alamos National Lab, which was called The Ranch, 00:14:30.900 --> 00:14:31.630 align:middle line:90% and so on. 00:14:31.630 --> 00:14:35.330 align:middle line:90% 00:14:35.330 --> 00:14:39.710 align:middle line:84% Some people will say, well, it's true that's very simple. 00:14:39.710 --> 00:14:44.170 align:middle line:84% But these weapons are heavy, and they're not practical 00:14:44.170 --> 00:14:46.050 align:middle line:90% military weapons these days. 00:14:46.050 --> 00:14:48.250 align:middle line:90% That's not true. 00:14:48.250 --> 00:14:53.490 align:middle line:90% So here is a photo of the W33. 00:14:53.490 --> 00:14:56.570 align:middle line:84% This is an artillery shell, a nuclear artillery shell 00:14:56.570 --> 00:15:00.850 align:middle line:90% that is shot out of a gun. 00:15:00.850 --> 00:15:03.370 align:middle line:84% This thing is 8 inches in diameter. 00:15:03.370 --> 00:15:07.250 align:middle line:84% It weighs 114 kilograms, which is the same weight 00:15:07.250 --> 00:15:09.970 align:middle line:84% as essentially the W80 thermonuclear warhead 00:15:09.970 --> 00:15:13.890 align:middle line:90% that we put on our ICBMs. 00:15:13.890 --> 00:15:17.090 align:middle line:90% And it's a gun type weapon. 00:15:17.090 --> 00:15:19.970 align:middle line:84% Super, super basic and simple to make. 00:15:19.970 --> 00:15:24.170 align:middle line:84% So I'm sure there are people in this class that 00:15:24.170 --> 00:15:29.360 align:middle line:84% could lift this thing and just carry it around. 00:15:29.360 --> 00:15:34.540 align:middle line:84% So yeah, these things can be small and very nasty. 00:15:34.540 --> 00:15:38.040 align:middle line:84% Oh, and I should also mention that the yield of this weapon 00:15:38.040 --> 00:15:40.580 align:middle line:90% is, I believe-- 00:15:40.580 --> 00:15:46.000 align:middle line:90% 00:15:46.000 --> 00:15:49.520 align:middle line:90% oh, blanking on the yield. 00:15:49.520 --> 00:15:52.760 align:middle line:84% It's much larger than the Hiroshima weapon. 00:15:52.760 --> 00:15:55.940 align:middle line:90% 53 kilotons, maybe? 00:15:55.940 --> 00:15:57.300 align:middle line:90% I'd have to go back and check. 00:15:57.300 --> 00:16:01.560 align:middle line:84% We built 1,200 of these, starting in 1956. 00:16:01.560 --> 00:16:07.000 align:middle line:84% So yeah, gun type weapons are still a serious consideration. 00:16:07.000 --> 00:16:10.760 align:middle line:84% The other type of weapon that we talk about 00:16:10.760 --> 00:16:13.120 align:middle line:90% are these implosion weapons. 00:16:13.120 --> 00:16:16.900 align:middle line:84% And the famous version is that dropped on Nagasaki, 00:16:16.900 --> 00:16:18.800 align:middle line:90% which is illustrated here. 00:16:18.800 --> 00:16:23.880 align:middle line:84% And the idea is that you compress 00:16:23.880 --> 00:16:28.830 align:middle line:84% the metal core-- in this case, you can use uranium, 00:16:28.830 --> 00:16:32.710 align:middle line:84% but why would you bother if you can do this with uranium? 00:16:32.710 --> 00:16:33.830 align:middle line:90% Just do this. 00:16:33.830 --> 00:16:39.990 align:middle line:84% So if you want to use plutonium, it turns out plutonium releases 00:16:39.990 --> 00:16:43.490 align:middle line:84% too many neutrons just sitting around. 00:16:43.490 --> 00:16:45.510 align:middle line:90% It has spontaneous fission. 00:16:45.510 --> 00:16:47.790 align:middle line:84% And so what happens is if you try 00:16:47.790 --> 00:16:53.550 align:middle line:84% to do this design with plutonium, as this bullet is 00:16:53.550 --> 00:16:58.110 align:middle line:84% being shot down the tube, there are neutrons flying off 00:16:58.110 --> 00:17:04.310 align:middle line:84% of this chunk, and it begins having a nuclear reaction 00:17:04.310 --> 00:17:07.310 align:middle line:84% well in advance of the two chunks coming together. 00:17:07.310 --> 00:17:12.030 align:middle line:84% And at that point, K, the criticality factor, 00:17:12.030 --> 00:17:13.750 align:middle line:90% isn't high enough. 00:17:13.750 --> 00:17:15.490 align:middle line:90% And so it starts heating up. 00:17:15.490 --> 00:17:20.030 align:middle line:84% But what it does is it runs the reaction kind of too slowly. 00:17:20.030 --> 00:17:23.371 align:middle line:84% And it makes a lot of heat, but not fast enough. 00:17:23.371 --> 00:17:24.829 align:middle line:84% And it eventually makes enough heat 00:17:24.829 --> 00:17:29.260 align:middle line:84% to push the thing apart before it runs all 80 generations. 00:17:29.260 --> 00:17:31.980 align:middle line:90% And that is called preignition. 00:17:31.980 --> 00:17:35.600 align:middle line:84% So they couldn't do this design with plutonium. 00:17:35.600 --> 00:17:40.140 align:middle line:84% And one cannot do this design with plutonium because you 00:17:40.140 --> 00:17:43.580 align:middle line:84% can't really shoot that using conventional explosives. 00:17:43.580 --> 00:17:47.260 align:middle line:84% You can't really shoot that chunk of uranium down 00:17:47.260 --> 00:17:49.980 align:middle line:90% the pipe fast enough. 00:17:49.980 --> 00:17:53.660 align:middle line:84% So the idea instead was that we would hydrodynamically 00:17:53.660 --> 00:17:56.860 align:middle line:90% compress the plutonium. 00:17:56.860 --> 00:18:02.540 align:middle line:84% And this was a big part of the engineering of the Manhattan 00:18:02.540 --> 00:18:04.780 align:middle line:90% Project. 00:18:04.780 --> 00:18:09.260 align:middle line:84% And so what you do is you go from the environment on the left 00:18:09.260 --> 00:18:11.260 align:middle line:90% to the environment on the right. 00:18:11.260 --> 00:18:14.280 align:middle line:84% And to put this as an illustration, 00:18:14.280 --> 00:18:17.020 align:middle line:84% now the mean-free path is getting shorter 00:18:17.020 --> 00:18:21.400 align:middle line:84% because the space between the atoms is more compressed. 00:18:21.400 --> 00:18:26.610 align:middle line:84% And so we return our subcritical chunk 00:18:26.610 --> 00:18:30.570 align:middle line:84% of plutonium into a supercritical chunk 00:18:30.570 --> 00:18:33.070 align:middle line:84% by just reducing the mean-free path. 00:18:33.070 --> 00:18:36.810 align:middle line:90% 00:18:36.810 --> 00:18:41.050 align:middle line:84% Most of the nuclear weapons in the arsenals of the world today 00:18:41.050 --> 00:18:44.650 align:middle line:90% are variations of this design. 00:18:44.650 --> 00:18:48.250 align:middle line:90% And it is more tricky. 00:18:48.250 --> 00:18:52.050 align:middle line:84% But also, countries have mostly got it right the first time 00:18:52.050 --> 00:18:52.710 align:middle line:90% they've tried. 00:18:52.710 --> 00:18:55.550 align:middle line:84% North Korea had some trouble with their first test, 00:18:55.550 --> 00:18:59.690 align:middle line:84% but it looks like, by the second test, they got it right. 00:18:59.690 --> 00:19:02.810 align:middle line:84% But most countries are also not confident enough 00:19:02.810 --> 00:19:05.090 align:middle line:84% in their designs of these weapons 00:19:05.090 --> 00:19:07.870 align:middle line:84% to field them without testing them. 00:19:07.870 --> 00:19:11.670 align:middle line:84% So we tested this design in Alamogordo. 00:19:11.670 --> 00:19:14.730 align:middle line:84% That's the test that you see in the movie Oppenheimer. 00:19:14.730 --> 00:19:19.050 align:middle line:84% And most other countries have also tested these designs. 00:19:19.050 --> 00:19:22.560 align:middle line:84% Today, these designs have been miniaturized 00:19:22.560 --> 00:19:26.280 align:middle line:84% to the point where they're basically roughly this big. 00:19:26.280 --> 00:19:28.600 align:middle line:90% They're pretty small. 00:19:28.600 --> 00:19:32.560 align:middle line:90% This original thing was huge. 00:19:32.560 --> 00:19:35.280 align:middle line:84% It was about as high as a person. 00:19:35.280 --> 00:19:36.380 align:middle line:90% It was a big thing. 00:19:36.380 --> 00:19:39.600 align:middle line:90% 00:19:39.600 --> 00:19:42.420 align:middle line:84% So those are the two basic designs. 00:19:42.420 --> 00:19:43.460 align:middle line:90% So here's Saudi Arabia. 00:19:43.460 --> 00:19:45.710 align:middle line:84% They're going to decide which design they want to use. 00:19:45.710 --> 00:19:50.500 align:middle line:84% And that will in part depend on what technologies they have. 00:19:50.500 --> 00:19:55.040 align:middle line:84% So if they just have reactors, reactors will make plutonium, 00:19:55.040 --> 00:19:59.680 align:middle line:84% and they will be forced to choose the implosion design. 00:19:59.680 --> 00:20:03.840 align:middle line:84% But if they have access to the other parts of the fuel cycle, 00:20:03.840 --> 00:20:08.200 align:middle line:84% or they have thorium, then they could potentially 00:20:08.200 --> 00:20:10.680 align:middle line:90% do the gun type design. 00:20:10.680 --> 00:20:13.820 align:middle line:84% Does anyone know what the story is with thorium, 00:20:13.820 --> 00:20:16.520 align:middle line:90% why it's a proliferation risk? 00:20:16.520 --> 00:20:18.863 align:middle line:90% Yeah? 00:20:18.863 --> 00:20:22.953 align:middle line:84% AUDIENCE: [INAUDIBLE] create protactinium-233, 00:20:22.953 --> 00:20:24.370 align:middle line:84% which you can separate chemically, 00:20:24.370 --> 00:20:26.810 align:middle line:90% and then you have [INAUDIBLE]. 00:20:26.810 --> 00:20:28.090 align:middle line:90% PROFESSOR: Exactly. 00:20:28.090 --> 00:20:34.390 align:middle line:84% So it's just the same as making plutonium from uranium. 00:20:34.390 --> 00:20:45.390 align:middle line:84% You just you go 232 Th plus N, 233 Th-- 00:20:45.390 --> 00:20:58.550 align:middle line:84% and that decays by a beta to 233 Pa 233 U. And turns out, 00:20:58.550 --> 00:21:01.670 align:middle line:84% uranium-233 is the very best isotope 00:21:01.670 --> 00:21:04.910 align:middle line:84% there is to make a nuclear weapon. 00:21:04.910 --> 00:21:08.950 align:middle line:84% It has a smaller critical mass than uranium-235. 00:21:08.950 --> 00:21:13.270 align:middle line:84% Critical mass is similar to that of uranium-- similar to that 00:21:13.270 --> 00:21:17.620 align:middle line:84% of plutonium, but it doesn't have the big spontaneous neutron 00:21:17.620 --> 00:21:21.020 align:middle line:90% background that is a problem. 00:21:21.020 --> 00:21:24.780 align:middle line:84% In fact, there are lots and lots of different isotopes 00:21:24.780 --> 00:21:27.600 align:middle line:84% from which you can, in principle, make nuclear weapons. 00:21:27.600 --> 00:21:30.820 align:middle line:90% And here's a list of them. 00:21:30.820 --> 00:21:33.500 align:middle line:84% So here's their half life in kilo 00:21:33.500 --> 00:21:37.140 align:middle line:84% years, the bare critical mass in kilograms. 00:21:37.140 --> 00:21:39.780 align:middle line:84% And this is the production rate and the number 00:21:39.780 --> 00:21:43.220 align:middle line:84% of kilograms per year per gigawatt of electricity 00:21:43.220 --> 00:21:45.580 align:middle line:90% that you generate. 00:21:45.580 --> 00:21:49.140 align:middle line:84% And so we can just look at these things. 00:21:49.140 --> 00:21:51.480 align:middle line:84% There's only one that is found in nature, 00:21:51.480 --> 00:21:54.400 align:middle line:90% and that is uranium-235. 00:21:54.400 --> 00:21:57.200 align:middle line:84% Technically, uranium-234 is also found in nature, 00:21:57.200 --> 00:22:00.700 align:middle line:90% but it's pretty scarce. 00:22:00.700 --> 00:22:03.500 align:middle line:84% And the bare critical mass is pretty large, 00:22:03.500 --> 00:22:07.780 align:middle line:90% so you would never use it. 00:22:07.780 --> 00:22:13.140 align:middle line:84% But the other ones, we can start eliminating some of them. 00:22:13.140 --> 00:22:15.850 align:middle line:90% So the curium isotopes-- 00:22:15.850 --> 00:22:22.250 align:middle line:84% they're just really not produced in any substantial quantity, 00:22:22.250 --> 00:22:25.810 align:middle line:84% especially relative to their critical masses. 00:22:25.810 --> 00:22:31.690 align:middle line:84% So this is not an efficient path to nuclear weapons. 00:22:31.690 --> 00:22:36.970 align:middle line:84% The light uranium isotopes, 233 synthesized 00:22:36.970 --> 00:22:39.830 align:middle line:84% in a reactor from uranium-235 and 238-- 00:22:39.830 --> 00:22:41.570 align:middle line:90% that's what this means. 00:22:41.570 --> 00:22:44.530 align:middle line:84% They're basically never produced because it's very rare that you 00:22:44.530 --> 00:22:50.730 align:middle line:84% get those n, 2n reactions that push the uranium isotope down 00:22:50.730 --> 00:22:52.690 align:middle line:90% in number. 00:22:52.690 --> 00:22:57.430 align:middle line:84% Same for neptunium-236-- just a very unlikely thing. 00:22:57.430 --> 00:23:01.130 align:middle line:90% So we can eliminate these. 00:23:01.130 --> 00:23:05.170 align:middle line:84% Then some of these have obnoxiously short half-lives, 00:23:05.170 --> 00:23:10.930 align:middle line:84% like americium, plutonium-241, uranium-232. 00:23:10.930 --> 00:23:16.942 align:middle line:84% And that means that they're very hot, hard to handle. 00:23:16.942 --> 00:23:18.400 align:middle line:84% If you try to make a weapon, you're 00:23:18.400 --> 00:23:20.480 align:middle line:84% going to be giving yourself a big dose. 00:23:20.480 --> 00:23:23.200 align:middle line:84% The people who talk about the thorium fuel cycle 00:23:23.200 --> 00:23:29.040 align:middle line:84% being proliferation-resistant are talking about uranium-232. 00:23:29.040 --> 00:23:32.240 align:middle line:84% What they're saying is if you do this reaction, 00:23:32.240 --> 00:23:35.880 align:middle line:84% then while this is in the reactor, there will be an n, 00:23:35.880 --> 00:23:43.680 align:middle line:84% 2n reaction that will drive some small fraction of this to U232. 00:23:43.680 --> 00:23:45.640 align:middle line:90% And this is very spicy. 00:23:45.640 --> 00:23:49.240 align:middle line:84% You can see from the half life is very short. 00:23:49.240 --> 00:23:52.920 align:middle line:84% But as Emil pointed out, if we are clever, 00:23:52.920 --> 00:23:59.380 align:middle line:84% and we separate out this before it is turned into uranium, 00:23:59.380 --> 00:24:02.120 align:middle line:84% so it's chemically different and therefore chemically 00:24:02.120 --> 00:24:07.440 align:middle line:84% discernible, we can bypass this step and not make the 232, 00:24:07.440 --> 00:24:11.080 align:middle line:84% let this just decay outside of the reactor into 233. 00:24:11.080 --> 00:24:16.070 align:middle line:84% So the thorium fuel cycle is predicated-- 00:24:16.070 --> 00:24:20.710 align:middle line:84% is proliferation resistant only if you have a dumb proliferator 00:24:20.710 --> 00:24:24.710 align:middle line:90% who doesn't understand things. 00:24:24.710 --> 00:24:26.970 align:middle line:84% This is really a lot of noise today. 00:24:26.970 --> 00:24:32.790 align:middle line:90% 00:24:32.790 --> 00:24:37.150 align:middle line:84% Then there are a few others that just the critical mass 00:24:37.150 --> 00:24:39.550 align:middle line:90% is kind of large. 00:24:39.550 --> 00:24:42.750 align:middle line:84% These are also kind of uninteresting. 00:24:42.750 --> 00:24:47.750 align:middle line:84% Uranium-234-- uninteresting, critical mass is too large. 00:24:47.750 --> 00:24:49.550 align:middle line:90% Now what is left? 00:24:49.550 --> 00:24:52.570 align:middle line:84% Well, uranium-235-- that's highly enriched uranium. 00:24:52.570 --> 00:24:54.070 align:middle line:90% We knew that. 00:24:54.070 --> 00:24:56.670 align:middle line:84% The lower plutonium isotopes, and 00:24:56.670 --> 00:25:00.510 align:middle line:84% in particular, plutonium-239, that's what we talk about. 00:25:00.510 --> 00:25:03.950 align:middle line:84% And then one that everyone kind of forgets about, 00:25:03.950 --> 00:25:10.140 align:middle line:84% which is neptunium-237, which it's not produced 00:25:10.140 --> 00:25:11.308 align:middle line:90% in very large quantities. 00:25:11.308 --> 00:25:13.100 align:middle line:84% If you're going to choose one or the other, 00:25:13.100 --> 00:25:17.040 align:middle line:84% you would choose the plutonium because you make more of it 00:25:17.040 --> 00:25:19.720 align:middle line:90% and you need less of it. 00:25:19.720 --> 00:25:25.100 align:middle line:90% 00:25:25.100 --> 00:25:26.980 align:middle line:90% You need less of it. 00:25:26.980 --> 00:25:31.020 align:middle line:90% But it's still a concern. 00:25:31.020 --> 00:25:33.580 align:middle line:84% And there are reprocessing programs 00:25:33.580 --> 00:25:38.020 align:middle line:84% that have large quantities of separated neptunium. 00:25:38.020 --> 00:25:44.220 align:middle line:84% And it actually does not fall under IAEA safeguards. 00:25:44.220 --> 00:25:49.280 align:middle line:84% It's kind of a loophole that we ought to deal with 00:25:49.280 --> 00:25:50.520 align:middle line:90% but hasn't been dealt with. 00:25:50.520 --> 00:25:55.640 align:middle line:90% 00:25:55.640 --> 00:25:59.220 align:middle line:84% So that's why we talk about plutonium and uranium. 00:25:59.220 --> 00:26:03.900 align:middle line:84% But the key takeaway here is actually kind of subtle. 00:26:03.900 --> 00:26:07.260 align:middle line:84% All of these things are explosive 00:26:07.260 --> 00:26:09.850 align:middle line:90% in the right quantities. 00:26:09.850 --> 00:26:15.170 align:middle line:84% So if you take mostly neptune, mostly plutonium, but then 00:26:15.170 --> 00:26:18.050 align:middle line:84% you mix in some of this other stuff, 00:26:18.050 --> 00:26:20.530 align:middle line:90% it still has a critical mass. 00:26:20.530 --> 00:26:23.650 align:middle line:84% It's some superposition of these, 00:26:23.650 --> 00:26:26.650 align:middle line:84% and you can still make a bomb out of it. 00:26:26.650 --> 00:26:31.170 align:middle line:84% You can't really denature it and turn it 00:26:31.170 --> 00:26:34.650 align:middle line:84% into something that isn't usable for weapon. 00:26:34.650 --> 00:26:37.690 align:middle line:84% All you can do is slightly move the critical mass around 00:26:37.690 --> 00:26:40.330 align:middle line:90% by adding some of these things. 00:26:40.330 --> 00:26:44.210 align:middle line:84% And that's really an important takeaway because, 00:26:44.210 --> 00:26:46.985 align:middle line:84% a lot of times, we talk about reactor-grade plutonium. 00:26:46.985 --> 00:26:48.610 align:middle line:84% Some people say reactor-grade plutonium 00:26:48.610 --> 00:26:50.250 align:middle line:90% isn't usable for weapons. 00:26:50.250 --> 00:26:52.370 align:middle line:84% Well, all reactor-grade plutonium means 00:26:52.370 --> 00:26:55.010 align:middle line:84% is it's got more of these plutonium isotopes, these higher 00:26:55.010 --> 00:26:56.450 align:middle line:90% plutonium isotopes. 00:26:56.450 --> 00:26:57.970 align:middle line:84% And yeah, what it does is it means 00:26:57.970 --> 00:27:02.130 align:middle line:84% that it's a little bit more spicy to deal with. 00:27:02.130 --> 00:27:06.080 align:middle line:84% You're not having a lot of 241, just a small amount of 241. 00:27:06.080 --> 00:27:11.360 align:middle line:84% And it changes the critical mass a little bit. 00:27:11.360 --> 00:27:12.420 align:middle line:90% So you can still use it. 00:27:12.420 --> 00:27:17.840 align:middle line:84% You just have to design the weapon a little differently. 00:27:17.840 --> 00:27:21.120 align:middle line:90% So that's an important takeaway. 00:27:21.120 --> 00:27:25.000 align:middle line:90% So this is a summary. 00:27:25.000 --> 00:27:26.980 align:middle line:84% We talked about spontaneous neutrons, 00:27:26.980 --> 00:27:33.200 align:middle line:84% which limits your plutonium usage to just one design. 00:27:33.200 --> 00:27:37.960 align:middle line:84% The amount that you need depends on how you do the assembly. 00:27:37.960 --> 00:27:41.320 align:middle line:84% Realistically, for uranium, something 00:27:41.320 --> 00:27:47.320 align:middle line:84% of the order of 15 to 20 kilograms of uranium-235 00:27:47.320 --> 00:27:52.440 align:middle line:84% or 3 to 8 kilograms of plutonium. 00:27:52.440 --> 00:27:57.960 align:middle line:84% Now the IAEA has an official number 00:27:57.960 --> 00:28:03.400 align:middle line:84% for the amount that they deem to be a notional nuclear weapon. 00:28:03.400 --> 00:28:06.890 align:middle line:84% If you ask them today if it's a notional nuclear weapon, 00:28:06.890 --> 00:28:08.730 align:middle line:84% some people there will say it's not, 00:28:08.730 --> 00:28:11.890 align:middle line:84% but it absolutely is and was when it was developed. 00:28:11.890 --> 00:28:13.550 align:middle line:84% And you have the historical documents 00:28:13.550 --> 00:28:16.547 align:middle line:90% that show this very clearly. 00:28:16.547 --> 00:28:18.630 align:middle line:84% And these are the numbers that they came up with-- 00:28:18.630 --> 00:28:21.150 align:middle line:90% 25 kilograms and 8 kilograms. 00:28:21.150 --> 00:28:24.922 align:middle line:84% And this is what they want to make sure is not diverted. 00:28:24.922 --> 00:28:26.630 align:middle line:84% And you might look at this and say, well, 00:28:26.630 --> 00:28:29.830 align:middle line:84% if you only need 3 kilograms, why 00:28:29.830 --> 00:28:34.030 align:middle line:84% are they saying the minimum acceptable quantity is 8? 00:28:34.030 --> 00:28:36.870 align:middle line:84% And yeah, people have worried about that. 00:28:36.870 --> 00:28:40.310 align:middle line:84% And their historical answer was, well, 00:28:40.310 --> 00:28:42.290 align:middle line:84% if you're in an advanced state, you need 3. 00:28:42.290 --> 00:28:45.670 align:middle line:84% But if you're not in an advanced state, 00:28:45.670 --> 00:28:48.990 align:middle line:84% you don't have a lot of knowledge, you might need 8. 00:28:48.990 --> 00:28:52.270 align:middle line:84% And also, there will be some process losses 00:28:52.270 --> 00:28:56.790 align:middle line:84% from the casting process of making the plutonium pit and so 00:28:56.790 --> 00:28:57.470 align:middle line:90% on. 00:28:57.470 --> 00:29:00.510 align:middle line:84% And yeah, these are all true statements, 00:29:00.510 --> 00:29:02.380 align:middle line:84% but the real motivation turned out 00:29:02.380 --> 00:29:07.140 align:middle line:84% to be that they couldn't do their accounting better 00:29:07.140 --> 00:29:08.800 align:middle line:90% than these levels. 00:29:08.800 --> 00:29:12.100 align:middle line:84% That was essentially if you try to push down these numbers, 00:29:12.100 --> 00:29:14.100 align:middle line:84% it just gets too expensive to do the accounting, 00:29:14.100 --> 00:29:16.880 align:middle line:84% and it becomes more than their budget will support. 00:29:16.880 --> 00:29:19.580 align:middle line:84% In fact, they already can't do the accounting 00:29:19.580 --> 00:29:22.820 align:middle line:90% for all the programs that exist. 00:29:22.820 --> 00:29:25.620 align:middle line:84% And so what they do is they say, well, we'll 00:29:25.620 --> 00:29:27.820 align:middle line:84% discern based on other information 00:29:27.820 --> 00:29:30.500 align:middle line:84% other than the accounting of fissile materials 00:29:30.500 --> 00:29:34.420 align:middle line:84% that, for certain countries, we don't really need to check. 00:29:34.420 --> 00:29:37.720 align:middle line:84% Which is a reasonable statement to make, 00:29:37.720 --> 00:29:40.040 align:middle line:84% but it doesn't treat everyone the same. 00:29:40.040 --> 00:29:49.100 align:middle line:90% 00:29:49.100 --> 00:29:52.900 align:middle line:90% What else can I say here? 00:29:52.900 --> 00:29:54.900 align:middle line:84% So just in case you're wondering how much 00:29:54.900 --> 00:29:58.140 align:middle line:84% 8 kilograms of plutonium is, there's 00:29:58.140 --> 00:30:01.870 align:middle line:84% a photo of the equivalent amount. 00:30:01.870 --> 00:30:04.690 align:middle line:90% 00:30:04.690 --> 00:30:05.790 align:middle line:90% Yeah, that much. 00:30:05.790 --> 00:30:07.170 align:middle line:90% It's heavy, though. 00:30:07.170 --> 00:30:10.130 align:middle line:90% 00:30:10.130 --> 00:30:12.450 align:middle line:90% It's dense stuff. 00:30:12.450 --> 00:30:16.730 align:middle line:84% So here's where we start having the technical connections 00:30:16.730 --> 00:30:19.370 align:middle line:90% to nuclear power. 00:30:19.370 --> 00:30:22.810 align:middle line:84% Ideally, we want to use nuclear power to mitigate 00:30:22.810 --> 00:30:24.110 align:middle line:90% the effect of climate. 00:30:24.110 --> 00:30:26.450 align:middle line:84% But we don't want to make this problem any worse. 00:30:26.450 --> 00:30:30.770 align:middle line:84% We don't want people diverting plutonium from the fuel cycle, 00:30:30.770 --> 00:30:32.205 align:middle line:90% from the reactor spent fuel. 00:30:32.205 --> 00:30:34.830 align:middle line:84% We don't want people using the enrichment process to make fuel, 00:30:34.830 --> 00:30:37.650 align:middle line:90% to make highly enriched uranium. 00:30:37.650 --> 00:30:40.690 align:middle line:84% And it turns out, as I've kind of just shown 00:30:40.690 --> 00:30:44.070 align:middle line:84% that, making the weapons themselves are, in a way, 00:30:44.070 --> 00:30:45.670 align:middle line:90% not all that complicated. 00:30:45.670 --> 00:30:47.550 align:middle line:90% We did this in 1945. 00:30:47.550 --> 00:30:49.692 align:middle line:84% North Korea has done this successfully. 00:30:49.692 --> 00:30:51.650 align:middle line:84% The hard part is actually getting the plutonium 00:30:51.650 --> 00:30:53.530 align:middle line:84% or getting the highly enriched uranium. 00:30:53.530 --> 00:30:58.160 align:middle line:84% And that's where various stages of the fuel cycle 00:30:58.160 --> 00:30:59.680 align:middle line:90% really come into play. 00:30:59.680 --> 00:31:04.400 align:middle line:84% So the once through fuel cycle is what we mostly talk about. 00:31:04.400 --> 00:31:07.880 align:middle line:84% And that's what we have in the United States. 00:31:07.880 --> 00:31:10.060 align:middle line:84% We put the uranium in the plant, we burn it, 00:31:10.060 --> 00:31:13.600 align:middle line:84% and then we just put the spent fuel in pool and call it a day. 00:31:13.600 --> 00:31:18.880 align:middle line:84% And the nice thing about that is, at no point is there 00:31:18.880 --> 00:31:25.260 align:middle line:84% any material in the fuel cycle that is directly weapons usable. 00:31:25.260 --> 00:31:28.440 align:middle line:84% So the uranium that comes out of the enrichment plant 00:31:28.440 --> 00:31:30.840 align:middle line:90% is something like up to 5%-- 00:31:30.840 --> 00:31:32.640 align:middle line:90% too low to make a bomb. 00:31:32.640 --> 00:31:35.500 align:middle line:84% Then you burn the fuel in the reactor. 00:31:35.500 --> 00:31:38.260 align:middle line:84% And yes, there is plutonium in that spent fuel. 00:31:38.260 --> 00:31:41.540 align:middle line:84% But remember, it's got all those other fission products in there. 00:31:41.540 --> 00:31:44.152 align:middle line:84% And so it's kind of self protecting. 00:31:44.152 --> 00:31:45.860 align:middle line:84% And you would need to do that separation. 00:31:45.860 --> 00:31:49.320 align:middle line:84% And so you would have to build a reprocessing plant 00:31:49.320 --> 00:31:52.520 align:middle line:84% to get your plutonium for the weapon. 00:31:52.520 --> 00:31:58.190 align:middle line:84% And as long as countries don't build reprocessing plants, 00:31:58.190 --> 00:32:01.470 align:middle line:84% they will not possess all of the technology needed 00:32:01.470 --> 00:32:05.870 align:middle line:84% to convert nuclear power into a nuclear weapons program, 00:32:05.870 --> 00:32:10.510 align:middle line:84% and that has been the foundation of nonproliferation 00:32:10.510 --> 00:32:12.910 align:middle line:84% since the Ford administration, which 00:32:12.910 --> 00:32:15.730 align:middle line:84% we said we will not reprocess here in the United States, 00:32:15.730 --> 00:32:17.230 align:middle line:84% and we will not support other people 00:32:17.230 --> 00:32:22.030 align:middle line:84% reprocessing because we don't want this plant 00:32:22.030 --> 00:32:25.150 align:middle line:84% to exist in any country that might 00:32:25.150 --> 00:32:29.030 align:middle line:84% convert their civil program into a weapons program. 00:32:29.030 --> 00:32:31.550 align:middle line:84% The problem arises when these fast reactor people show up 00:32:31.550 --> 00:32:34.750 align:middle line:84% and say, well, we want to do this as a matter of course 00:32:34.750 --> 00:32:37.540 align:middle line:84% or when the nuclear waste people show up and are like, 00:32:37.540 --> 00:32:39.290 align:middle line:84% we don't know where to put our spent fuel. 00:32:39.290 --> 00:32:41.630 align:middle line:84% Therefore, let's just do some reprocessing 00:32:41.630 --> 00:32:43.895 align:middle line:84% to kick the can down the road and delay 00:32:43.895 --> 00:32:45.270 align:middle line:84% the decision of where we're going 00:32:45.270 --> 00:32:48.230 align:middle line:84% to put our geologic repository, like Japan. 00:32:48.230 --> 00:32:51.550 align:middle line:84% And so now you have the French and the Japanese 00:32:51.550 --> 00:32:56.020 align:middle line:84% doing this thing with separation plutonium as a matter of course. 00:32:56.020 --> 00:32:59.700 align:middle line:84% And that gives us this dedicated pathway 00:32:59.700 --> 00:33:03.660 align:middle line:84% in which you don't need any additional facilities to get 00:33:03.660 --> 00:33:06.020 align:middle line:90% to a bomb. 00:33:06.020 --> 00:33:10.622 align:middle line:84% The other concern-- this is the connection 00:33:10.622 --> 00:33:12.080 align:middle line:84% to the civilian nuclear fuel cycle. 00:33:12.080 --> 00:33:14.500 align:middle line:84% But we should remember that most countries that 00:33:14.500 --> 00:33:17.540 align:middle line:84% have nuclear weapons have dedicated 00:33:17.540 --> 00:33:20.300 align:middle line:84% nuclear weapons production reactors 00:33:20.300 --> 00:33:27.360 align:middle line:84% that most countries have not used these civilian-- now, 00:33:27.360 --> 00:33:30.340 align:middle line:84% it's not true that no country has contemplated this. 00:33:30.340 --> 00:33:33.720 align:middle line:84% But this is how the United States did it, for example. 00:33:33.720 --> 00:33:37.660 align:middle line:84% So what's to stop a country like Iran 00:33:37.660 --> 00:33:42.020 align:middle line:84% building a dedicated plutonium production reactor? 00:33:42.020 --> 00:33:42.680 align:middle line:90% They had one. 00:33:42.680 --> 00:33:44.940 align:middle line:90% It was called Arak. 00:33:44.940 --> 00:33:48.060 align:middle line:84% And they could just do this on their own 00:33:48.060 --> 00:33:49.860 align:middle line:90% without civilian nuclear power. 00:33:49.860 --> 00:33:51.440 align:middle line:90% So this is the counterargument. 00:33:51.440 --> 00:33:54.490 align:middle line:90% Well, they can just do this. 00:33:54.490 --> 00:33:55.790 align:middle line:90% Why don't they do that? 00:33:55.790 --> 00:33:58.730 align:middle line:84% And then the second thing is they could also 00:33:58.730 --> 00:34:01.930 align:middle line:84% just build a dedicated enrichment plant 00:34:01.930 --> 00:34:04.690 align:middle line:84% to enrich uranium and make a bomb. 00:34:04.690 --> 00:34:07.410 align:middle line:84% And so again, this is the other counterargument 00:34:07.410 --> 00:34:09.969 align:middle line:90% against a connection. 00:34:09.969 --> 00:34:15.050 align:middle line:84% So let's look at these a little bit more. 00:34:15.050 --> 00:34:19.610 align:middle line:84% So who has actually done this plutonium from power reactors? 00:34:19.610 --> 00:34:21.850 align:middle line:84% Two countries, France and the United Kingdom, 00:34:21.850 --> 00:34:26.489 align:middle line:84% both made weapons using their power reactors. 00:34:26.489 --> 00:34:28.610 align:middle line:90% So yeah, it has been done. 00:34:28.610 --> 00:34:32.170 align:middle line:84% Argentina, Brazil, Sweden, and Taiwan 00:34:32.170 --> 00:34:34.770 align:middle line:84% all had programs where this was the plan. 00:34:34.770 --> 00:34:38.570 align:middle line:84% They would just divert fuel from their power program 00:34:38.570 --> 00:34:40.210 align:middle line:90% and build a bomb. 00:34:40.210 --> 00:34:43.389 align:middle line:84% And any country that has a power reactor can do this. 00:34:43.389 --> 00:34:47.250 align:middle line:90% 00:34:47.250 --> 00:34:50.480 align:middle line:84% The Argentine and Brazilian programs 00:34:50.480 --> 00:34:53.260 align:middle line:84% were operated under military governments. 00:34:53.260 --> 00:34:57.520 align:middle line:84% Those governments collapsed before they were successful. 00:34:57.520 --> 00:35:01.800 align:middle line:84% The Swedish program has an interesting story. 00:35:01.800 --> 00:35:05.480 align:middle line:84% They designed their nuclear power program from the beginning 00:35:05.480 --> 00:35:07.720 align:middle line:90% to be dual use. 00:35:07.720 --> 00:35:11.620 align:middle line:84% Then the cost started getting out of control, 00:35:11.620 --> 00:35:15.560 align:middle line:84% and there was a lot of domestic opposition to nuclear power 00:35:15.560 --> 00:35:18.000 align:middle line:90% that was becoming a problem. 00:35:18.000 --> 00:35:20.600 align:middle line:84% But, of course, they had this hidden agenda 00:35:20.600 --> 00:35:22.700 align:middle line:84% of making nuclear weapons with the program. 00:35:22.700 --> 00:35:24.800 align:middle line:84% So they were kind of trying to advance it. 00:35:24.800 --> 00:35:28.103 align:middle line:84% And then the United States realized what was happening. 00:35:28.103 --> 00:35:29.853 align:middle line:84% And the United States swooped in and said, 00:35:29.853 --> 00:35:32.800 align:middle line:84% you know what, Sweden, if you abandoned the reactors 00:35:32.800 --> 00:35:34.880 align:middle line:84% that you've designed for your program 00:35:34.880 --> 00:35:39.040 align:middle line:84% and instead accept light water reactor once-through fuel 00:35:39.040 --> 00:35:45.760 align:middle line:84% cycle from us, then we'll give you some discounts. 00:35:45.760 --> 00:35:50.350 align:middle line:84% Then we'll make your domestic political problem go away. 00:35:50.350 --> 00:35:54.030 align:middle line:84% And so they finally gave up their weapons ambitions. 00:35:54.030 --> 00:35:56.450 align:middle line:84% And Taiwan also tried to do this, 00:35:56.450 --> 00:35:59.830 align:middle line:84% and the United States found out and went to Taiwan and said, 00:35:59.830 --> 00:36:03.030 align:middle line:84% you know what, if you don't stop this, 00:36:03.030 --> 00:36:05.470 align:middle line:84% we're not going to defend you against Mainland China. 00:36:05.470 --> 00:36:09.150 align:middle line:90% And they went, OK, sorry. 00:36:09.150 --> 00:36:14.750 align:middle line:84% So nonproliferation has been successful 00:36:14.750 --> 00:36:15.850 align:middle line:90% in two of these cases. 00:36:15.850 --> 00:36:21.310 align:middle line:84% And two of these cases imploded on their own accord. 00:36:21.310 --> 00:36:24.010 align:middle line:84% In case you're wondering which reactors at France-- 00:36:24.010 --> 00:36:31.950 align:middle line:84% this is the G2 and G3 reactor at Marcoule that they used. 00:36:31.950 --> 00:36:33.450 align:middle line:90% We all know how that works. 00:36:33.450 --> 00:36:37.010 align:middle line:90% 00:36:37.010 --> 00:36:39.890 align:middle line:90% So here's how you do it. 00:36:39.890 --> 00:36:43.790 align:middle line:84% As I showed you earlier, you can use any combination 00:36:43.790 --> 00:36:47.220 align:middle line:84% of those isotopes to come up with a combination that 00:36:47.220 --> 00:36:51.020 align:middle line:90% is useful for nuclear weapons. 00:36:51.020 --> 00:36:55.380 align:middle line:84% But typically, you ideally don't want 00:36:55.380 --> 00:36:59.220 align:middle line:84% to have a lot of these isotopes, especially 00:36:59.220 --> 00:37:00.940 align:middle line:84% these even numbered isotopes, which 00:37:00.940 --> 00:37:05.100 align:middle line:84% tend to have higher spontaneous fission rates. 00:37:05.100 --> 00:37:10.000 align:middle line:84% So you would ideally not want to burn your fuel normally. 00:37:10.000 --> 00:37:12.380 align:middle line:84% We talk about burning fuel all the way up to, nowadays, 00:37:12.380 --> 00:37:16.040 align:middle line:84% 45,000-50,000 megawatt days per metric ton. 00:37:16.040 --> 00:37:18.460 align:middle line:84% So we're really over here these days. 00:37:18.460 --> 00:37:22.620 align:middle line:84% And so the plutonium is not great. 00:37:22.620 --> 00:37:24.600 align:middle line:84% It has a lot of these other isotopes. 00:37:24.600 --> 00:37:28.420 align:middle line:84% Ideally, we want just pure plutonium-239. 00:37:28.420 --> 00:37:33.300 align:middle line:84% But if you pull out the uranium early, 00:37:33.300 --> 00:37:36.780 align:middle line:90% you get weapons-grade stuff. 00:37:36.780 --> 00:37:40.980 align:middle line:90% And so two ways you can do this. 00:37:40.980 --> 00:37:46.010 align:middle line:84% One is you could just stop the reactor. 00:37:46.010 --> 00:37:47.730 align:middle line:84% Now maybe people will be watching. 00:37:47.730 --> 00:37:50.170 align:middle line:84% Oh, why did that reactor shut down? 00:37:50.170 --> 00:37:52.510 align:middle line:84% And why are they unloading the fuel from that reactor? 00:37:52.510 --> 00:37:56.570 align:middle line:84% And so you might be tipping your hand as to what you're up to. 00:37:56.570 --> 00:37:59.690 align:middle line:84% On the other hand, maybe you have a problem. 00:37:59.690 --> 00:38:03.250 align:middle line:90% Oh, a reactor had a leak. 00:38:03.250 --> 00:38:05.930 align:middle line:84% One of our fuel pins catastrophically 00:38:05.930 --> 00:38:07.110 align:middle line:90% failed something. 00:38:07.110 --> 00:38:08.850 align:middle line:90% We have to unload the fuel. 00:38:08.850 --> 00:38:10.490 align:middle line:90% We have to do some maintenance. 00:38:10.490 --> 00:38:15.090 align:middle line:84% And so you can come up with an excuse for doing this. 00:38:15.090 --> 00:38:18.330 align:middle line:84% But you don't really even have to do that. 00:38:18.330 --> 00:38:22.050 align:middle line:84% The other thing you can do is when 00:38:22.050 --> 00:38:25.850 align:middle line:84% we build PWRs, the very first load 00:38:25.850 --> 00:38:29.690 align:middle line:84% that we put in the PWR has a lower enrichment 00:38:29.690 --> 00:38:34.370 align:middle line:84% and is burned much less to break in the system. 00:38:34.370 --> 00:38:38.850 align:middle line:84% And that load that is sitting in every spent fuel 00:38:38.850 --> 00:38:40.810 align:middle line:90% pool in the world. 00:38:40.810 --> 00:38:44.320 align:middle line:84% It's the first batch of fuel that we put in every reactor, 00:38:44.320 --> 00:38:47.760 align:middle line:84% and the plutonium in that first batch is pretty good. 00:38:47.760 --> 00:38:52.280 align:middle line:84% And so every reactor has this first batch sitting around 00:38:52.280 --> 00:38:55.380 align:middle line:84% that we could just reprocess and turn into fuel. 00:38:55.380 --> 00:39:05.320 align:middle line:90% 00:39:05.320 --> 00:39:12.240 align:middle line:84% This green area is the typical fuel from CANDU reactors. 00:39:12.240 --> 00:39:15.200 align:middle line:84% So CANDU reactors, heavy water reactors, 00:39:15.200 --> 00:39:18.040 align:middle line:84% they overcome the need for enrichment 00:39:18.040 --> 00:39:22.200 align:middle line:84% by having water moderator that is already 00:39:22.200 --> 00:39:26.640 align:middle line:84% full of extra neutrons by using deuterium instead of protium 00:39:26.640 --> 00:39:27.840 align:middle line:90% light water. 00:39:27.840 --> 00:39:31.880 align:middle line:84% And so they go in with a higher concentration of uranium-238. 00:39:31.880 --> 00:39:33.980 align:middle line:84% So you have more neutron capture on 238, 00:39:33.980 --> 00:39:35.360 align:middle line:90% which makes more plutonium. 00:39:35.360 --> 00:39:40.510 align:middle line:84% And so what you wind up with is stuff that is already not 00:39:40.510 --> 00:39:43.070 align:middle line:84% exactly weapons-grade but pretty close to it 00:39:43.070 --> 00:39:44.950 align:middle line:90% under normal operation. 00:39:44.950 --> 00:39:48.030 align:middle line:84% So CANDU reactors are particularly problematic, 00:39:48.030 --> 00:39:54.950 align:middle line:84% and a number of countries, like India and South Korea, 00:39:54.950 --> 00:39:57.550 align:middle line:84% have built CANDU reactors very early 00:39:57.550 --> 00:40:02.630 align:middle line:84% on in their nuclear programs because of this fact. 00:40:02.630 --> 00:40:07.790 align:middle line:84% It gave them a cache of spent fuel 00:40:07.790 --> 00:40:09.830 align:middle line:84% from which they could make weapons 00:40:09.830 --> 00:40:12.077 align:middle line:84% in the event they decided they needed it. 00:40:12.077 --> 00:40:13.910 align:middle line:84% And then they said, oh, they're not economic 00:40:13.910 --> 00:40:17.670 align:middle line:90% and then switched to PWRs. 00:40:17.670 --> 00:40:23.238 align:middle line:84% But yeah, this is the beginning of many countries. 00:40:23.238 --> 00:40:25.030 align:middle line:84% Now some people-- I don't know, does anyone 00:40:25.030 --> 00:40:28.790 align:middle line:84% not believe me about the reactor-grade plutonium? 00:40:28.790 --> 00:40:30.790 align:middle line:84% Or has anyone heard that reactor-grade plutonium 00:40:30.790 --> 00:40:32.050 align:middle line:90% can't be used? 00:40:32.050 --> 00:40:35.510 align:middle line:90% 00:40:35.510 --> 00:40:38.820 align:middle line:84% I won't ask if you don't believe me. 00:40:38.820 --> 00:40:41.500 align:middle line:84% There's an official US government Department 00:40:41.500 --> 00:40:44.340 align:middle line:90% of Energy statement on this. 00:40:44.340 --> 00:40:46.220 align:middle line:84% And I think this is long, but I think 00:40:46.220 --> 00:40:48.015 align:middle line:90% it's worth me just reading it. 00:40:48.015 --> 00:40:50.140 align:middle line:84% "Designing and building an effective nuclear weapon 00:40:50.140 --> 00:40:54.140 align:middle line:84% using reactor-grade plutonium is less convenient than using 00:40:54.140 --> 00:40:55.280 align:middle line:90% weapon-grade plutonium. 00:40:55.280 --> 00:40:57.540 align:middle line:84% The degree to which these obstacles can be overcome 00:40:57.540 --> 00:41:01.220 align:middle line:84% depends on the sophistication of the state or group attempting 00:41:01.220 --> 00:41:02.957 align:middle line:90% to produce a nuclear weapon. 00:41:02.957 --> 00:41:04.540 align:middle line:84% At the lowest level of sophistication, 00:41:04.540 --> 00:41:09.100 align:middle line:84% a potential proliferating state or subnational group--" 00:41:09.100 --> 00:41:11.020 align:middle line:90% by which they mean terrorist-- 00:41:11.020 --> 00:41:14.300 align:middle line:84% "using designs and technologies no more sophisticated than those 00:41:14.300 --> 00:41:16.460 align:middle line:84% used in first-generation nuclear weapons--" i.e. 00:41:16.460 --> 00:41:23.420 align:middle line:84% 1945-- "could build a nuclear weapon 00:41:23.420 --> 00:41:25.420 align:middle line:84% from reactor-grade plutonium that 00:41:25.420 --> 00:41:29.560 align:middle line:84% would have an assured, reliable yield of one or a few kilotons, 00:41:29.560 --> 00:41:32.745 align:middle line:84% and probably a yield significantly higher than that. 00:41:32.745 --> 00:41:34.120 align:middle line:84% At the other end of the spectrum, 00:41:34.120 --> 00:41:36.453 align:middle line:84% advanced nuclear weapon states such as the United States 00:41:36.453 --> 00:41:38.290 align:middle line:84% and Russia, using modern designs, 00:41:38.290 --> 00:41:40.770 align:middle line:84% could produce weapons from reactor-grade plutonium, 00:41:40.770 --> 00:41:43.630 align:middle line:84% having reliable explosive yields, weights, 00:41:43.630 --> 00:41:45.930 align:middle line:84% and other characteristics generally comparable to those 00:41:45.930 --> 00:41:48.770 align:middle line:84% of weapons from weapons-grade plutonium." 00:41:48.770 --> 00:41:52.690 align:middle line:84% It is the case that you can take any weapon, any US weapon, 00:41:52.690 --> 00:41:55.510 align:middle line:84% and swap out the plutonium for reactor-grade plutonium, 00:41:55.510 --> 00:41:58.850 align:middle line:90% and it will work just fine. 00:41:58.850 --> 00:42:00.650 align:middle line:84% "Proliferating states using designs 00:42:00.650 --> 00:42:02.890 align:middle line:84% of intermediate sophistication could produce weapons 00:42:02.890 --> 00:42:04.570 align:middle line:84% with assured yields substantially higher 00:42:04.570 --> 00:42:08.010 align:middle line:84% than the kiloton range possible with simple, first-generation 00:42:08.010 --> 00:42:09.070 align:middle line:90% nuclear devices. 00:42:09.070 --> 00:42:10.450 align:middle line:84% In short, reactor-grade plutonium 00:42:10.450 --> 00:42:14.350 align:middle line:84% is weapons-usable, whether by unsophisticated proliferators 00:42:14.350 --> 00:42:16.090 align:middle line:84% or advanced nuclear weapon states. 00:42:16.090 --> 00:42:18.450 align:middle line:84% Theft of separated plutonium, whether weapons-grade 00:42:18.450 --> 00:42:22.090 align:middle line:84% or reactor-grade, would pose a grave security risk." 00:42:22.090 --> 00:42:27.130 align:middle line:90% And so that is why-- 00:42:27.130 --> 00:42:29.490 align:middle line:90% do I have a photo-- 00:42:29.490 --> 00:42:32.210 align:middle line:84% I worry about these little canisters 00:42:32.210 --> 00:42:35.700 align:middle line:90% of separated plutonium. 00:42:35.700 --> 00:42:41.003 align:middle line:84% So let's say a state has this-- yep? 00:42:41.003 --> 00:42:42.420 align:middle line:84% AUDIENCE: I have a quick question. 00:42:42.420 --> 00:42:47.560 align:middle line:84% So reactor-grade plutonium is essentially almost swappable 00:42:47.560 --> 00:42:49.520 align:middle line:90% with weapons-grade plutonium? 00:42:49.520 --> 00:42:54.480 align:middle line:84% Why did we spend so much on making weapons-grade plutonium? 00:42:54.480 --> 00:42:56.520 align:middle line:90% PROFESSOR: Safety. 00:42:56.520 --> 00:42:59.480 align:middle line:84% The dose rate off of reactor-grade plutonium 00:42:59.480 --> 00:43:01.840 align:middle line:90% is substantially higher. 00:43:01.840 --> 00:43:07.400 align:middle line:84% And our weapons are designed so that the people who 00:43:07.400 --> 00:43:09.600 align:middle line:84% handle those weapons in the military 00:43:09.600 --> 00:43:11.560 align:middle line:90% don't get a substantial dose. 00:43:11.560 --> 00:43:15.280 align:middle line:84% In fact, we have very special called ivory-grade plutonium, 00:43:15.280 --> 00:43:18.460 align:middle line:84% which is ivory is 99 point whatever percent pure-- 00:43:18.460 --> 00:43:20.720 align:middle line:90% you know the commercial-- 00:43:20.720 --> 00:43:27.120 align:middle line:84% that you can sleep on it so that people in submarines 00:43:27.120 --> 00:43:32.350 align:middle line:84% could literally sleep on the nuclear torpedoes, which 00:43:32.350 --> 00:43:36.510 align:middle line:84% I don't know if you've ever been in a submarine. 00:43:36.510 --> 00:43:39.950 align:middle line:84% Often, people bunk in the torpedo room 00:43:39.950 --> 00:43:41.050 align:middle line:90% next to the torpedo. 00:43:41.050 --> 00:43:43.770 align:middle line:90% So you have to be-- that's why. 00:43:43.770 --> 00:43:50.810 align:middle line:90% 00:43:50.810 --> 00:43:54.290 align:middle line:84% So let's say you're Saudi Arabia. 00:43:54.290 --> 00:43:57.150 align:middle line:84% You've bought your nuclear reactor from the United States 00:43:57.150 --> 00:44:00.390 align:middle line:84% because the United States wants to give you a reactor. 00:44:00.390 --> 00:44:01.730 align:middle line:90% What do you really have to do? 00:44:01.730 --> 00:44:04.110 align:middle line:84% Well, you either have spent fuel like this, 00:44:04.110 --> 00:44:06.790 align:middle line:84% or you have it like this, and now you 00:44:06.790 --> 00:44:09.230 align:middle line:90% need to do the reprocessing. 00:44:09.230 --> 00:44:13.010 align:middle line:84% How hard would it be to build that reprocessing plant? 00:44:13.010 --> 00:44:16.810 align:middle line:84% So I showed you in the last lecture, 00:44:16.810 --> 00:44:19.510 align:middle line:84% last set of slides, this $20 billion 00:44:19.510 --> 00:44:25.270 align:middle line:84% super complex reprocessing plant that looked like a large city. 00:44:25.270 --> 00:44:31.620 align:middle line:84% What if you really didn't care about high volumes 00:44:31.620 --> 00:44:36.100 align:middle line:84% and purified waste streams and vitrification 00:44:36.100 --> 00:44:38.880 align:middle line:84% and all the rest of it, and you just wanted the plutonium? 00:44:38.880 --> 00:44:40.500 align:middle line:90% How hard would it be? 00:44:40.500 --> 00:44:46.620 align:middle line:84% Well, in 1977, Oak Ridge asked this question, 00:44:46.620 --> 00:44:48.300 align:middle line:90% and they did a study. 00:44:48.300 --> 00:44:51.780 align:middle line:84% And this is the first page of the memo from that study. 00:44:51.780 --> 00:44:57.440 align:middle line:84% And if you read it, what they propose is that, with a backhoe, 00:44:57.440 --> 00:45:01.460 align:middle line:84% you could dig a swimming pool hole, fill it with water. 00:45:01.460 --> 00:45:04.300 align:middle line:84% You would put your fuel bundle in the swimming pool 00:45:04.300 --> 00:45:07.140 align:middle line:84% because you need to protect yourself from radiation. 00:45:07.140 --> 00:45:09.240 align:middle line:90% You need to cut the fuel. 00:45:09.240 --> 00:45:11.760 align:middle line:84% So you get a carbide cutting blade, 00:45:11.760 --> 00:45:14.555 align:middle line:84% like you would use on an angle grinder. 00:45:14.555 --> 00:45:16.180 align:middle line:84% And it doesn't work under water, so you 00:45:16.180 --> 00:45:20.140 align:middle line:84% need a chain going up to a motor which is above the water. 00:45:20.140 --> 00:45:21.860 align:middle line:84% And you cut up the fuel under the water, 00:45:21.860 --> 00:45:24.640 align:middle line:84% and the fuel would fall into a basket. 00:45:24.640 --> 00:45:27.940 align:middle line:84% And then, using a crane, you would transport that basket 00:45:27.940 --> 00:45:32.250 align:middle line:84% into a series of stainless steel tanks, 00:45:32.250 --> 00:45:35.530 align:middle line:84% and they suggest you order the tanks from the cheesemaking 00:45:35.530 --> 00:45:37.330 align:middle line:84% industry, from the dairy industry, 00:45:37.330 --> 00:45:40.170 align:middle line:84% for use as stainless steel tanks. 00:45:40.170 --> 00:45:45.450 align:middle line:84% And you just do some straightforward non purex 00:45:45.450 --> 00:45:51.170 align:middle line:84% simplified chemical precipitate lead bismuth process 00:45:51.170 --> 00:45:54.570 align:middle line:84% and precipitate out the plutonium. 00:45:54.570 --> 00:45:57.290 align:middle line:84% And they conclude that, when you're done, 00:45:57.290 --> 00:46:00.290 align:middle line:84% it would take four to six months to build this plant that you 00:46:00.290 --> 00:46:02.930 align:middle line:84% could mail order from the dairy catalog 00:46:02.930 --> 00:46:06.610 align:middle line:84% and that, once you had it built, you 00:46:06.610 --> 00:46:09.330 align:middle line:84% could extract your first weapon quantity of plutonium 00:46:09.330 --> 00:46:12.300 align:middle line:90% in about one week. 00:46:12.300 --> 00:46:14.050 align:middle line:84% And you could potentially build this thing 00:46:14.050 --> 00:46:16.930 align:middle line:84% without anyone really noticing what you were up to. 00:46:16.930 --> 00:46:20.290 align:middle line:84% It looks like you're building a cheese factory with a swimming 00:46:20.290 --> 00:46:23.370 align:middle line:90% pool. 00:46:23.370 --> 00:46:25.830 align:middle line:90% And that's not that hard. 00:46:25.830 --> 00:46:29.520 align:middle line:90% 00:46:29.520 --> 00:46:31.360 align:middle line:90% Are you likely to get caught? 00:46:31.360 --> 00:46:32.680 align:middle line:90% You might. 00:46:32.680 --> 00:46:35.400 align:middle line:84% It depends on how good you are at operational security 00:46:35.400 --> 00:46:37.720 align:middle line:84% and whether you go tell large parts of the government 00:46:37.720 --> 00:46:40.360 align:middle line:90% and some spy finds out. 00:46:40.360 --> 00:46:43.980 align:middle line:84% But you might not, and you might get away with this. 00:46:43.980 --> 00:46:48.000 align:middle line:84% And once this plant were built somewhere in the country, who 00:46:48.000 --> 00:46:51.360 align:middle line:84% knows where, and you divert your uranium fuel 00:46:51.360 --> 00:46:54.823 align:middle line:84% bundles from your reactor, maybe the IAEA 00:46:54.823 --> 00:46:56.740 align:middle line:84% will notice that the fuel bundles are missing. 00:46:56.740 --> 00:46:58.198 align:middle line:84% Maybe they'll notice it right away. 00:46:58.198 --> 00:47:00.520 align:middle line:84% Maybe they'll take them six months to notice it. 00:47:00.520 --> 00:47:02.400 align:middle line:84% But if they notice it right away, 00:47:02.400 --> 00:47:04.520 align:middle line:90% who's to say where they went? 00:47:04.520 --> 00:47:06.160 align:middle line:90% Where do I bomb? 00:47:06.160 --> 00:47:08.020 align:middle line:84% You've got to find that facility. 00:47:08.020 --> 00:47:15.640 align:middle line:84% So this is the concern that it's not actually all that hard. 00:47:15.640 --> 00:47:18.960 align:middle line:84% Of course, it's much easier if you have that facility already 00:47:18.960 --> 00:47:24.870 align:middle line:84% built, and this is the other pathway that countries can take. 00:47:24.870 --> 00:47:28.950 align:middle line:84% And China, France, Germany, Japan, Russia, 00:47:28.950 --> 00:47:33.270 align:middle line:84% and the UK basically all decided this was an interesting pathway 00:47:33.270 --> 00:47:37.150 align:middle line:90% to building their bomb. 00:47:37.150 --> 00:47:38.550 align:middle line:84% So what they said is, oh, we need 00:47:38.550 --> 00:47:42.270 align:middle line:84% to do the closed fuel cycle for various reasons. 00:47:42.270 --> 00:47:46.710 align:middle line:84% It's true, for example, in Japan, the Rokkasho Plant, which 00:47:46.710 --> 00:47:49.390 align:middle line:84% cost them $20 billion, is because they 00:47:49.390 --> 00:47:53.270 align:middle line:84% don't know what to do with the spent nuclear fuel. 00:47:53.270 --> 00:47:57.510 align:middle line:84% But actually, there was a reprocessing plant, Tokaimura, 00:47:57.510 --> 00:48:01.590 align:middle line:84% which was built before Rokkasho was built. 00:48:01.590 --> 00:48:03.390 align:middle line:84% And this was why it was like, oh, it 00:48:03.390 --> 00:48:06.750 align:middle line:84% was a research plan to see if we want to close the fuel cycle. 00:48:06.750 --> 00:48:09.910 align:middle line:84% And it made a lot of plutonium, and then they shut the plant. 00:48:09.910 --> 00:48:14.910 align:middle line:84% And so people have countries have said over time 00:48:14.910 --> 00:48:18.430 align:middle line:84% that we're going to do some research into this closed fuel 00:48:18.430 --> 00:48:21.190 align:middle line:84% cycle concept, and they build these plants. 00:48:21.190 --> 00:48:23.420 align:middle line:84% And everyone knows that these plants exist, 00:48:23.420 --> 00:48:25.500 align:middle line:84% and they operate them openly, and they 00:48:25.500 --> 00:48:28.300 align:middle line:84% say that we're just doing the fast reactor thing, 00:48:28.300 --> 00:48:32.900 align:middle line:84% and then they go, oh, it's too expensive, and they give up. 00:48:32.900 --> 00:48:36.620 align:middle line:84% But it's really been a weapons program 00:48:36.620 --> 00:48:39.700 align:middle line:90% for quite a number of these. 00:48:39.700 --> 00:48:43.440 align:middle line:84% Pakistan and South Korea have been trying to do this. 00:48:43.440 --> 00:48:46.680 align:middle line:84% South Korea has been slowly inching along. 00:48:46.680 --> 00:48:48.920 align:middle line:84% But they don't want to irritate the US government. 00:48:48.920 --> 00:48:52.740 align:middle line:84% So there's constant negotiations about what they can and cannot 00:48:52.740 --> 00:48:53.620 align:middle line:90% do. 00:48:53.620 --> 00:48:56.040 align:middle line:84% But they are slowly moving in this direction. 00:48:56.040 --> 00:48:59.420 align:middle line:90% 00:48:59.420 --> 00:49:01.140 align:middle line:84% So of course, you go from this situation 00:49:01.140 --> 00:49:02.980 align:middle line:84% where you have to divert the spent fuel 00:49:02.980 --> 00:49:07.820 align:middle line:84% bundle to your secret reprocessing site to this, 00:49:07.820 --> 00:49:09.900 align:middle line:84% as we've talked about, everything 00:49:09.900 --> 00:49:13.780 align:middle line:90% has been done for you basically. 00:49:13.780 --> 00:49:15.380 align:middle line:84% Fortunately, today, most of the world 00:49:15.380 --> 00:49:19.100 align:middle line:84% has been convinced that routine separation of plutonium 00:49:19.100 --> 00:49:23.690 align:middle line:84% is just not economic and doesn't make sense. 00:49:23.690 --> 00:49:27.090 align:middle line:84% Of the nonweapons states, states that don't already 00:49:27.090 --> 00:49:31.490 align:middle line:84% have nuclear weapons, Japan is the only country doing it. 00:49:31.490 --> 00:49:35.130 align:middle line:84% And because it does it, and because it 00:49:35.130 --> 00:49:37.370 align:middle line:84% is so close to having a bomb at any given moment 00:49:37.370 --> 00:49:39.850 align:middle line:84% because it has separated plutonium, 00:49:39.850 --> 00:49:43.690 align:middle line:84% the IAEA, the International Atomic Energy Agency 00:49:43.690 --> 00:49:47.950 align:middle line:84% that inspects these facilities, last time I checked, 00:49:47.950 --> 00:49:50.770 align:middle line:84% spends about a full third of its inspection 00:49:50.770 --> 00:49:56.050 align:middle line:84% budget on this plant in Japan because it's just 00:49:56.050 --> 00:49:58.710 align:middle line:84% so close to being ready for nuclear weapons. 00:49:58.710 --> 00:50:01.490 align:middle line:84% And you can imagine, if we have the closed fuel cycle, 00:50:01.490 --> 00:50:04.490 align:middle line:84% and this is being spread all around the world, 00:50:04.490 --> 00:50:08.570 align:middle line:84% just how difficult it would be, almost impossible, 00:50:08.570 --> 00:50:15.850 align:middle line:84% to prevent some country from tipping over. 00:50:15.850 --> 00:50:19.000 align:middle line:84% I've already talked about this, so 00:50:19.000 --> 00:50:22.720 align:middle line:84% let me talk about the dedicated pathways 00:50:22.720 --> 00:50:25.220 align:middle line:84% that countries could take, and then we'll wrap up. 00:50:25.220 --> 00:50:28.120 align:middle line:90% 00:50:28.120 --> 00:50:31.380 align:middle line:84% So this is also maybe not that difficult, 00:50:31.380 --> 00:50:36.458 align:middle line:84% but it does require building up a dedicated program. 00:50:36.458 --> 00:50:38.000 align:middle line:84% And you have to decide whether you're 00:50:38.000 --> 00:50:40.863 align:middle line:84% going to try to do it secretly or overtly. 00:50:40.863 --> 00:50:42.780 align:middle line:84% And generally, when you're building a reactor, 00:50:42.780 --> 00:50:45.960 align:middle line:84% it's too big of a construction project to keep it secret. 00:50:45.960 --> 00:50:48.760 align:middle line:84% So then you have to come up with an excuse for why 00:50:48.760 --> 00:50:49.820 align:middle line:90% you're doing this. 00:50:49.820 --> 00:50:52.480 align:middle line:90% 00:50:52.480 --> 00:50:55.680 align:middle line:84% The excuse that many countries give 00:50:55.680 --> 00:50:59.200 align:middle line:84% is that they're interested in nuclear power, 00:50:59.200 --> 00:51:02.480 align:middle line:84% and they want to train people, and they want to test materials 00:51:02.480 --> 00:51:03.960 align:middle line:90% to design reactors. 00:51:03.960 --> 00:51:07.400 align:middle line:84% And they're just building MIT, MITR, the MIT reactor. 00:51:07.400 --> 00:51:11.520 align:middle line:84% Basically, we're just doing just doing what MIT does. 00:51:11.520 --> 00:51:15.280 align:middle line:84% But then they choose the design of their reactor, 00:51:15.280 --> 00:51:19.710 align:middle line:84% unlike the MIT reactor, to be a reactor that produces plutonium 00:51:19.710 --> 00:51:20.430 align:middle line:90% well. 00:51:20.430 --> 00:51:25.070 align:middle line:84% So the research reactor that the Iranians designed 00:51:25.070 --> 00:51:28.950 align:middle line:84% was a natural uranium-fueled heavy water reactor, 00:51:28.950 --> 00:51:30.490 align:middle line:90% just like a CANDU reactor. 00:51:30.490 --> 00:51:32.990 align:middle line:84% It produces great-quality plutonium, 00:51:32.990 --> 00:51:34.790 align:middle line:84% and it was large enough that it would 00:51:34.790 --> 00:51:41.110 align:middle line:84% produce significant quantities in on the order of a year. 00:51:41.110 --> 00:51:49.430 align:middle line:84% So the problem is that unless you have nuclear power, even 00:51:49.430 --> 00:51:53.670 align:middle line:84% though you can do this independently of nuclear power, 00:51:53.670 --> 00:51:59.550 align:middle line:84% your excuse depends on the idea that you are building 00:51:59.550 --> 00:52:02.150 align:middle line:90% nuclear power at the same time. 00:52:02.150 --> 00:52:07.250 align:middle line:84% So it still has this connection into nuclear power. 00:52:07.250 --> 00:52:11.230 align:middle line:84% And if instead we said, well, nuclear power is only 00:52:11.230 --> 00:52:13.190 align:middle line:84% for certain countries that don't have access 00:52:13.190 --> 00:52:16.420 align:middle line:84% to high-quality wind and solar, it 00:52:16.420 --> 00:52:19.580 align:middle line:84% would be really hard for Saudi Arabia to do this 00:52:19.580 --> 00:52:22.020 align:middle line:84% because you look at Saudi Arabia and say, what exactly 00:52:22.020 --> 00:52:26.820 align:middle line:90% is your solar shortage here? 00:52:26.820 --> 00:52:29.860 align:middle line:84% But nevertheless, some reason the US nuclear industry 00:52:29.860 --> 00:52:33.600 align:middle line:84% is very excited about giving Saudi Arabia nuclear power. 00:52:33.600 --> 00:52:36.980 align:middle line:90% 00:52:36.980 --> 00:52:42.340 align:middle line:84% So let me just give you a sense of what this path entails. 00:52:42.340 --> 00:52:52.660 align:middle line:84% This is in 2005, is a satellite image of the Arak site in Iran. 00:52:52.660 --> 00:52:55.660 align:middle line:84% This is where they were breaking ground. 00:52:55.660 --> 00:52:58.020 align:middle line:84% They're going to build an indigenously designed, 00:52:58.020 --> 00:53:02.220 align:middle line:84% 40-megawatt, heavy water-moderated reactor. 00:53:02.220 --> 00:53:06.480 align:middle line:84% It produced about 11 kilograms of plutonium per year. 00:53:06.480 --> 00:53:08.960 align:middle line:84% So that's enough for one to two nuclear weapons, 00:53:08.960 --> 00:53:12.490 align:middle line:84% depending on how advanced your weapons are-- 00:53:12.490 --> 00:53:13.450 align:middle line:90% 2005. 00:53:13.450 --> 00:53:20.290 align:middle line:84% Here's what it looked like five years later in 2010. 00:53:20.290 --> 00:53:24.290 align:middle line:90% And it's almost complete. 00:53:24.290 --> 00:53:34.370 align:middle line:84% At this point, they were really getting ready to load fuel 00:53:34.370 --> 00:53:35.550 align:middle line:90% into the reactor. 00:53:35.550 --> 00:53:38.730 align:middle line:84% They had basically built most of this stuff. 00:53:38.730 --> 00:53:40.850 align:middle line:84% It looks like the time scale for country 00:53:40.850 --> 00:53:44.290 align:middle line:84% to do this that has basically minimal experience 00:53:44.290 --> 00:53:48.470 align:middle line:84% in nuclear engineering is on the order of a decade, 00:53:48.470 --> 00:53:50.190 align:middle line:90% 12 years, maybe 15 years. 00:53:50.190 --> 00:53:53.290 align:middle line:84% Depends on how much money they pour into it 00:53:53.290 --> 00:53:57.090 align:middle line:84% and how sophisticated their existing engineering 00:53:57.090 --> 00:53:59.210 align:middle line:90% infrastructure is. 00:53:59.210 --> 00:54:05.890 align:middle line:84% So it is a pathway to a weapon, but it's kind of the long play. 00:54:05.890 --> 00:54:09.770 align:middle line:84% It's not the backup option in case, 00:54:09.770 --> 00:54:12.660 align:middle line:84% like, we don't need nuclear weapons, 00:54:12.660 --> 00:54:14.170 align:middle line:84% but just in case someone attacks us, 00:54:14.170 --> 00:54:15.920 align:middle line:84% we'd like to be able to make them quickly. 00:54:15.920 --> 00:54:17.760 align:middle line:90% That's how Japan thinks. 00:54:17.760 --> 00:54:20.880 align:middle line:84% And so that's why Japan wants to have the plutonium 00:54:20.880 --> 00:54:24.240 align:middle line:90% ready to go just in case. 00:54:24.240 --> 00:54:26.400 align:middle line:84% This option doesn't give you that if you 00:54:26.400 --> 00:54:28.720 align:middle line:84% have to start building this thing from scratch. 00:54:28.720 --> 00:54:31.880 align:middle line:84% And so that's again where nuclear power 00:54:31.880 --> 00:54:34.200 align:middle line:90% changes the calculation. 00:54:34.200 --> 00:54:39.460 align:middle line:84% It says if you're not intending to pursue nuclear weapons, 00:54:39.460 --> 00:54:43.560 align:middle line:84% absolutely, but you just want to security blanket, 00:54:43.560 --> 00:54:45.180 align:middle line:84% nuclear power will get you there. 00:54:45.180 --> 00:54:48.400 align:middle line:84% And I think that's basically why Saudi Arabia wants 00:54:48.400 --> 00:54:49.640 align:middle line:90% nuclear power today. 00:54:49.640 --> 00:54:52.920 align:middle line:84% They just they want to have all this stuff just in case 00:54:52.920 --> 00:54:56.000 align:middle line:90% they need it. 00:54:56.000 --> 00:55:01.400 align:middle line:90% Finally, let's look at uranium. 00:55:01.400 --> 00:55:07.560 align:middle line:84% Historically, this was regarded as the most difficult path 00:55:07.560 --> 00:55:10.310 align:middle line:90% to uranium enrichment. 00:55:10.310 --> 00:55:11.530 align:middle line:90% Let me see if I have-- 00:55:11.530 --> 00:55:14.150 align:middle line:90% 00:55:14.150 --> 00:55:16.710 align:middle line:90% I have some slides-- 00:55:16.710 --> 00:55:21.270 align:middle line:84% the most difficult path to a nuclear bomb. 00:55:21.270 --> 00:55:25.030 align:middle line:90% That has since changed in 1990. 00:55:25.030 --> 00:55:28.670 align:middle line:84% Pakistan broke the mold on this when they developed 00:55:28.670 --> 00:55:32.070 align:middle line:90% their own centrifuge program. 00:55:32.070 --> 00:55:36.950 align:middle line:84% And if you want, I can tell you the history 00:55:36.950 --> 00:55:38.650 align:middle line:90% of this in a separate talk. 00:55:38.650 --> 00:55:43.230 align:middle line:90% It's an interesting story. 00:55:43.230 --> 00:55:48.310 align:middle line:84% Since then, Iraq, Iran, Libya, and North Korea 00:55:48.310 --> 00:55:49.850 align:middle line:90% have all followed suit. 00:55:49.850 --> 00:55:53.230 align:middle line:84% They all also pursued uranium enrichment, 00:55:53.230 --> 00:55:55.830 align:middle line:84% dedicated uranium enrichment, as a path 00:55:55.830 --> 00:55:59.390 align:middle line:84% to building their nuclear weapons. 00:55:59.390 --> 00:56:04.750 align:middle line:84% The reason-- it turns out that making gas centrifuges, 00:56:04.750 --> 00:56:06.150 align:middle line:84% the modern way you do enrichment, 00:56:06.150 --> 00:56:10.620 align:middle line:84% is a lot easier than the old form of enrichment, which 00:56:10.620 --> 00:56:11.920 align:middle line:90% was called gaseous diffusion. 00:56:11.920 --> 00:56:15.420 align:middle line:84% And I'll show you that in a moment. 00:56:15.420 --> 00:56:19.300 align:middle line:84% Now, again, what happens if you get caught building this thing, 00:56:19.300 --> 00:56:21.700 align:middle line:90% as the Iranians did? 00:56:21.700 --> 00:56:25.220 align:middle line:84% Well, the Iranians said we have this power reactor we're 00:56:25.220 --> 00:56:26.560 align:middle line:90% building called [INAUDIBLE]. 00:56:26.560 --> 00:56:30.660 align:middle line:84% It's big-- it started as a German reactor design, 00:56:30.660 --> 00:56:32.500 align:middle line:84% and then was modified by the Russians 00:56:32.500 --> 00:56:39.260 align:middle line:84% as some weird hybrid reactor, but basically a big PWR. 00:56:39.260 --> 00:56:42.420 align:middle line:84% And they said, we want to be able to make the fuel ourselves, 00:56:42.420 --> 00:56:45.340 align:middle line:84% and that's why we have enrichment program. 00:56:45.340 --> 00:56:48.620 align:middle line:90% And no one really believed them. 00:56:48.620 --> 00:56:52.540 align:middle line:84% But the fact that they had that reactor 00:56:52.540 --> 00:56:59.660 align:middle line:84% meant our hands were tied under the NPT of really accusing Iran 00:56:59.660 --> 00:57:01.620 align:middle line:90% of pursuing a weapons program. 00:57:01.620 --> 00:57:05.610 align:middle line:84% And it kind of dragged things out for decades 00:57:05.610 --> 00:57:08.608 align:middle line:84% and made the problem a lot worse. 00:57:08.608 --> 00:57:11.150 align:middle line:84% If they had just been doing this without the Bushehr reactor, 00:57:11.150 --> 00:57:14.290 align:middle line:84% we would have been-- you're guilty of trying 00:57:14.290 --> 00:57:18.330 align:middle line:84% to make nuclear weapons, and there would be no discussion. 00:57:18.330 --> 00:57:23.515 align:middle line:90% So again, you need the excuse. 00:57:23.515 --> 00:57:25.890 align:middle line:84% And that's where the connection to civilian nuclear power 00:57:25.890 --> 00:57:27.530 align:middle line:90% comes in. 00:57:27.530 --> 00:57:29.810 align:middle line:84% So just let's look at what this entails. 00:57:29.810 --> 00:57:32.970 align:middle line:90% First, you need uranium. 00:57:32.970 --> 00:57:34.490 align:middle line:90% It's pretty common. 00:57:34.490 --> 00:57:36.450 align:middle line:90% It's more common than tin. 00:57:36.450 --> 00:57:41.450 align:middle line:84% Every country has enough uranium except for, maybe, I don't know, 00:57:41.450 --> 00:57:44.170 align:middle line:90% Monaco. 00:57:44.170 --> 00:57:48.770 align:middle line:84% Every country has enough uranium to build a bomb. 00:57:48.770 --> 00:57:51.450 align:middle line:84% Not every country has economically viable deposits 00:57:51.450 --> 00:57:54.050 align:middle line:84% that they could extract and sell uranium 00:57:54.050 --> 00:57:56.050 align:middle line:90% competitively in the market. 00:57:56.050 --> 00:57:59.310 align:middle line:84% But everyone has enough uranium sitting around to make a bomb. 00:57:59.310 --> 00:58:02.050 align:middle line:84% And just to give you an example of that, 00:58:02.050 --> 00:58:07.640 align:middle line:84% Iraq, during its weapons program, had a phosphate mine. 00:58:07.640 --> 00:58:10.280 align:middle line:84% You mine phosphates to make soap, 00:58:10.280 --> 00:58:14.120 align:middle line:84% and it happens to be that uranium tends 00:58:14.120 --> 00:58:17.640 align:middle line:90% to coexist in phosphate ores. 00:58:17.640 --> 00:58:20.120 align:middle line:84% So they went to the phosphate mine tailing pond, 00:58:20.120 --> 00:58:22.600 align:middle line:84% where they had all this waste, and they just 00:58:22.600 --> 00:58:26.400 align:middle line:84% took that and reprocessed it to extract the uranium 00:58:26.400 --> 00:58:28.120 align:middle line:90% for their weapons program. 00:58:28.120 --> 00:58:30.520 align:middle line:90% It's around. 00:58:30.520 --> 00:58:33.040 align:middle line:90% It's not uncommon. 00:58:33.040 --> 00:58:36.463 align:middle line:84% Previously, maybe you could do that. 00:58:36.463 --> 00:58:37.880 align:middle line:84% You could go and take the tailings 00:58:37.880 --> 00:58:39.920 align:middle line:90% out of at a phosphate mine. 00:58:39.920 --> 00:58:41.380 align:middle line:90% You could do this. 00:58:41.380 --> 00:58:44.160 align:middle line:84% We talked about this the other day is in-situ leach mining. 00:58:44.160 --> 00:58:47.600 align:middle line:84% You drill a hole in the ground, and you pump sulfuric acid down 00:58:47.600 --> 00:58:51.680 align:middle line:84% or hydrogen peroxide down, and you dissolve uranium, 00:58:51.680 --> 00:58:53.440 align:middle line:90% and then you pump it back up. 00:58:53.440 --> 00:58:56.453 align:middle line:84% And this does not look like a big-- 00:58:56.453 --> 00:58:58.120 align:middle line:84% you look at this from a satellite photo, 00:58:58.120 --> 00:59:00.240 align:middle line:84% and you have no idea what's going on here. 00:59:00.240 --> 00:59:04.030 align:middle line:90% Is this a well? 00:59:04.030 --> 00:59:06.230 align:middle line:84% You could cover this up with some sheds. 00:59:06.230 --> 00:59:08.170 align:middle line:90% This is not hard to hide. 00:59:08.170 --> 00:59:11.095 align:middle line:90% 00:59:11.095 --> 00:59:12.970 align:middle line:84% Of course, now you have to do the enrichment. 00:59:12.970 --> 00:59:16.350 align:middle line:84% You have to go from natural uranium, which is only 0.7% 00:59:16.350 --> 00:59:19.370 align:middle line:84% uranium-235, to something up here. 00:59:19.370 --> 00:59:26.350 align:middle line:84% And so you need to build centrifuges to do that. 00:59:26.350 --> 00:59:30.590 align:middle line:84% And here's an example of why people thought this was hard. 00:59:30.590 --> 00:59:33.390 align:middle line:84% Here's the building that the United States 00:59:33.390 --> 00:59:35.110 align:middle line:84% built at the end of the Manhattan Project 00:59:35.110 --> 00:59:38.950 align:middle line:90% to do its uranium enrichment. 00:59:38.950 --> 00:59:41.150 align:middle line:90% It's called K-25. 00:59:41.150 --> 00:59:45.370 align:middle line:84% It's 44 acres of land in a single building, 00:59:45.370 --> 00:59:49.710 align:middle line:84% employed 12,000 people, and used, in one building, 00:59:49.710 --> 00:59:52.130 align:middle line:84% three times the electricity of the entire city of Detroit, 00:59:52.130 --> 00:59:54.110 align:middle line:90% Michigan. 00:59:54.110 --> 00:59:56.510 align:middle line:84% This is a photo of a small section 00:59:56.510 --> 00:59:57.850 align:middle line:90% of the inside of the building. 00:59:57.850 --> 01:00:03.140 align:middle line:84% And you can see the size of the pipe works. 01:00:03.140 --> 01:00:05.800 align:middle line:90% And for scale, this is a person. 01:00:05.800 --> 01:00:09.140 align:middle line:90% 01:00:09.140 --> 01:00:12.380 align:middle line:84% And there were 44 acres of this stuff-- 01:00:12.380 --> 01:00:16.120 align:middle line:84% huge compressors and all of this stuff. 01:00:16.120 --> 01:00:23.280 align:middle line:84% So this is why people thought other countries can't do this. 01:00:23.280 --> 01:00:25.280 align:middle line:84% We'll pick up on the rest of enrichment. 01:00:25.280 --> 01:00:29.550 align:middle line:84% We'll talk about centrifuges next time, Monday. 01:00:29.550 --> 01:00:58.000 align:middle line:90%