The Black Sea Experiment: Data taking and legacy

[00:00:03] In fact, I hold out hope. I think maybe what I've really learned is that things can change dramatically

[00:00:10] very quickly for the good, maybe as well as the bad, but right now we're going through

[00:00:15] rather discouraging times in the field of nuclear weapons and arms control and

[00:00:22] when people myself or students become discouraged and you know sort of bordering unhoopless

[00:00:28] I like to remind them in 1983 there were there was a Reagan administration official talking about

[00:00:35] the need to be prepared to fight and win a nuclear war with enough shovels

[00:00:40] we were going to get through it. Oh my gosh. And just in a few years that all changed.

[00:00:53] Welcome to My Nuclear Life. I'm Shelly Lesher. This is the second of two episodes on the Black Sea

[00:00:59] experiment. In the last episode Tom, Velikov and their teams had arranged for seismic tests of both

[00:01:06] US and Soviet nuclear testing sites and demonstrated they could work together. Frank had given a briefing

[00:01:12] to Gorbachev and everyone was making headway in Congress and the court of public opinion.

[00:01:18] Velikov had just given Tom the go-ahead to purchase some very costly germanium detectors.

[00:01:24] Now we're ready for the Black Sea experiment.

[00:01:30] Frank von Hippel picks up our story. Remember at the time Frank was the chairman of the Federation

[00:01:38] of American Scientists. But the last stop was the Black Sea experiment. Okay. What happened was

[00:01:45] the Soviets wanted to include sea launch nuclear armed cruise missiles in the start

[00:01:52] treaty, the first start treaty. And the US said it doesn't make any sense because you can't tell

[00:01:58] the difference between a conventionally armed cruise missile and a nuclear armed cruise missile.

[00:02:03] Could you remind us what the start treaty is? The start treaty was the second nuclear arms

[00:02:07] reduction treaty that came out of the Gorbachev-Riggin developing a relationship. And the

[00:02:14] purpose was to reduce the number of strategic warheads on missiles and bombers by half on each

[00:02:24] side. Okay. And it was after the Intermediate Range Nuclear Forces Treaty, which had eliminated

[00:02:32] land-based intermediate range ballistic and cruise missiles, which were at that time

[00:02:38] in Europe, sort of in a confrontation in Europe. So we're heading in the right direction.

[00:02:42] Yeah. The sea launch cruise missiles on US ships were within range of Moscow, the cruise

[00:02:50] missile. And so they wanted to include them as well. But the US had said, you know, how can

[00:02:56] you do this? You can't tell the difference between a conventionally and nuclear arms.

[00:03:01] And so an Institute director came to Velikov and said, I have a way to detect the

[00:03:08] difference from kilometers away. And Velikov, without checking, went to Gorbachev.

[00:03:15] And Gorbachev announced that they had a way to do this.

[00:03:19] Did the Institute person even say what that way was or just like, hey, I have a way?

[00:03:23] And Velikov was like, okay, great.

[00:03:25] It was not clear. I mean, Saab Jaf, he concluded that this was made no sense.

[00:03:32] And he was very embarrassed that his chairman had misled Gorbachev.

[00:03:39] And so he came to me and he said, well, let's do a joint study on how you can detect warheads.

[00:03:46] And we did and wrote a book on the subject.

[00:03:50] Reversing the arms race.

[00:03:51] Reversing the arms race. How to achieve and verify deep

[00:03:56] reductions in nuclear arsenal. So it was broader than just this, but it included

[00:04:02] a study of how you could detect warheads.

[00:04:05] So could you detect them from kilometers away?

[00:04:08] No, but there was something better than what we demonstrated that I'll tell you about.

[00:04:14] Okay.

[00:04:15] We did the study and Steve Federer played a leading part in it.

[00:04:19] And we had some Soviet scientists as well.

[00:04:22] It was a joint study between the committee of Soviet scientists and the FAS.

[00:04:28] So who got the team together?

[00:04:31] Saab Jaf and me. Saab Jaf brought a couple of people from his institute and I recruited a U.S.

[00:04:38] group.

[00:04:38] How'd you recruit Steve Federer?

[00:04:40] Well, I knew Steve Federer from way back. And so he was an obvious choice.

[00:04:45] And you thought, hey, he can read gamma rays.

[00:04:47] Yeah. Well, yeah. And there were some other people too.

[00:04:51] And so we wrote this and Tom came to us and said, well, why don't we demonstrate this?

[00:04:56] Then Velikov went to Gorbachev and Gorbachev blessed it.

[00:05:01] Tom Cochran from the Natural Resource Defense Council returns to our story.

[00:05:06] He is working with Velikov on joint demonstrations and brought the germane

[00:05:10] detectors to Russia.

[00:05:12] So you guys decide to buy these detectors and then you got a ship.

[00:05:16] I go to the FAS group that I've been working with because I'm working with Frank doing his,

[00:05:24] you know, the studies they're doing and get their help in putting together a team,

[00:05:31] which was Federer myself. Lee Grotsen from MIT who worked with Union of Concerned Scientists.

[00:05:38] Marty Zucker at Brookhaven Aston Laboratory.

[00:05:42] Harvey Lynch at Stanford Linear Accelerator.

[00:05:44] So we put together a team, bought two sets of instruments and we need to test them and figure

[00:05:50] out how to use them and so forth. So we go up to Brookhaven and take one set of

[00:06:00] one detector and one multi-channel analyzer and Federer and I go up.

[00:06:05] I happened to have, because I bought in 1979,

[00:06:09] a slug of depleted uranium, 15 pounds of depleted uranium, which under the Nuclear

[00:06:15] Regulatory Commission regulations, an individual could own it without a license

[00:06:23] for research or educational purposes. So I bought this slug and I'd been using it for

[00:06:31] Research and Educational Purposes.

[00:06:33] Yes, it fit in a coke can and I would take it and have a talk about nuclear weapons.

[00:06:40] So we take this slug and the equipment up to Brookhaven, take it up on the airplane,

[00:06:46] no problem, go out to Brookhaven, check everything out, all the equipment out.

[00:06:50] Federer and I come back to JFK Airport. A bunch of men come over, we're having a hamburger

[00:06:55] before we get on a flight and a bunch of guys come over and says, come with us.

[00:07:02] Is that your suitcase over there? Which they had taken to as far away as they could

[00:07:08] out the window. I said, yeah, that's my suitcase. And he said, well, what is it?

[00:07:13] And I said, well, it's 15 pounds of depleted uranium.

[00:07:16] They said, well, we're not going to let you put it on the plane.

[00:07:19] I said, can I leave it here with you? I'm coming up here tomorrow for a meeting in New York.

[00:07:25] They said, no, but you can take it over and check it at the baggage check.

[00:07:32] It goes on the plane.

[00:07:34] It wouldn't let it on the plane, but they would let me take it to the center of the terminal

[00:07:38] and put it in the baggage check overnight. Now go home, come back the next day, pick it up,

[00:07:44] take it to New York City and FedEx it home. Crazy. But anyway, so we had all,

[00:07:50] we checked out the instruments and then in July, all the arrangements are made. And we had such

[00:07:57] good fortune with the congressional delegation during the seismic studies. We organized another

[00:08:05] delegation. This one led by Congressman John Spratt, Bob Carr from your neck of the woods,

[00:08:13] who had been on the previous delegation and Congressman Olin from Virginia.

[00:08:19] We took the team, the two sets of instruments. We took some NRDC people. We took what we called

[00:08:27] observers, which were people I was working with through Von Hippel, Glee de Von Hippel, Barry

[00:08:34] Blackman, Bill Ark and Valerie Thomas. And then we took three congressmen and they had their aides.

[00:08:41] So we show up Moscow in Fladiata. They put us up on a hospital ship the night before we go

[00:08:49] out on to the cruiser, which was then called the Slava. It was the flagship of the Black Sea Fleet.

[00:08:56] There's this whole thing that Steve told me about with only having 10 minutes to take data.

[00:09:02] How are you able to negotiate the amount of time to make data?

[00:09:09] We have a reception on this hospital ship where everybody's staying. They came to me the night

[00:09:14] before. Well, it's this reception. You can record but for 10 minutes.

[00:09:21] And that's not something you expected?

[00:09:23] No. The night before, the day before we tested two sets of instruments and one of them didn't work.

[00:09:30] So now we're down to one set of instruments.

[00:09:32] Good thing you had two.

[00:09:33] Yeah, lucky. So Steve and I are sitting on the launcher over the warhead. They told us

[00:09:40] where the hot sweet spot was because they'd been there for a couple of days measuring and KBG

[00:09:48] guys standing over us. And so we do some practice when we test our instruments get everything right.

[00:09:56] So we recorded an extra 14 minutes of data practicing before we were all set to do the

[00:10:04] real thing. So we came on with 24 minutes a day.

[00:10:09] This is the first time we hear from Steve Federer. He is a professor from the University of Maryland

[00:10:14] and as you will hear is the one actually taking the measurements.

[00:10:20] You come in, it's the group of US scientists and then there's the Russian scientists. So this

[00:10:25] is July 5th, 1989 when you're on the Black Sea and you have seven different detectors used.

[00:10:31] So why are you using all these different types of detectors?

[00:10:34] Well, our main detector and in fact I think the only one that we were responsible for was the

[00:10:40] high-purity germanium detector. And that was unique in being able to make high resolution

[00:10:47] measurements where you could resolve the individual gamma rays that are associated with the decay

[00:10:53] of particular isotopes of plutonium and uranium. And that's valuable for being able to

[00:11:01] conclusively determine that it's plutonium high-enriched uranium that you're measuring.

[00:11:08] The other instruments were provided by Soviet scientists. The one that I remember the

[00:11:14] best is a large neutron detector that was mounted in a helicopter that flew over the ship

[00:11:22] and was able to detect the neutron emissions from the warhead. So that's more sensitive because

[00:11:30] there's a smaller neutron background. And plutonium, which is in almost all warheads,

[00:11:36] is a pretty potent, pretty bright neutron source. And you can detect it just by flying over

[00:11:42] in a helicopter. Yes. Which is different than what you had to do. Yes. Let's go back to your

[00:11:47] high-purity germanium detector because the germanium detectors that I use now have to be

[00:11:52] cooled with liquid nitrogen. Was this the case? Because it says here it was 2K EV resolution.

[00:11:58] So that's a nice germanium detector. Tom Cochran purchased a commercial unit

[00:12:05] and we brought the detector with us. I can't remember whether we probably needed an export

[00:12:12] license for this. I think we did bring our own doer, but of course we needed the liquid nitrogen

[00:12:17] and the Soviets supplied the liquid nitrogen for that. And of course we had to wait for it to cool

[00:12:23] down and to calibrate it. I think we brought our own calibration source, which in the form of

[00:12:30] Coleman mantles, which have thorium or I think impregnated with thorium, because obviously

[00:12:39] transporting radioactive sources, I mean real radioactive sources or calibration sources probably

[00:12:46] would have also required an export license. But they didn't say anything about your mantles.

[00:12:52] No, no. We're going camping, no lantern, but we have the mantles.

[00:13:00] Well, I don't know whether we looked at other common items. I think a banana probably is too

[00:13:06] weak to use as a calibration source. But I wonder if you could do that now,

[00:13:12] bring a mantle. Well, I think so. But I wonder if the TSA would stop you at this point because of

[00:13:18] the radiation? I don't know, but this was the pre-911 days. Of course, yeah. I think I have my

[00:13:25] favorite sentence in your paper. We made the following measurements on the slava,

[00:13:30] three measurements totaling about 24 minutes on the launch tube directly above the warhead.

[00:13:37] Yes, they allowed me to sit right on top of the launch tube right above the warhead. They had

[00:13:45] made a little X at the point that was right below the warhead. But I verified that that

[00:13:51] was the location by running a little like simple dagger counter along the tube to in fact

[00:13:58] confirm that this was the place with the highest count rate.

[00:14:02] So wait, you're like straddling the missile basically?

[00:14:06] Yeah, sitting on top. I think you can see a photo of me maybe not in that article. We have other

[00:14:12] photos of me sitting on top like, yes, like Slim Pickens and Dr. Strangelove.

[00:14:18] Are you like sitting there with your instrument and everybody's staring at you?

[00:14:21] Yeah, they're standing around. I was basically the person responsible for placing the detector and

[00:14:29] operating the multi-channel analyzer to make sure that it was counting properly.

[00:14:34] Were you scared you were going to drop something? Because there's not a lot of room up there.

[00:14:37] No, but it's surprising. You could easily walk around. It wasn't so small. I don't

[00:14:43] remember feeling uncomfortable, but then I'm fine in high places.

[00:14:49] And it says 24 minutes so you didn't get that all in one go?

[00:14:55] No, and this is a little embarrassing. So we were only supposed to count for 10 minutes

[00:15:01] and the Soviets were worried about a long count time. I later learned and

[00:15:07] Frank von Hippel will confirm this that the head of the Soviet laboratory

[00:15:12] didn't want this measurement made at all with a high-resolution detector because of the fear that

[00:15:19] it would reveal classified information. But I just decided to keep on counting and I was

[00:15:28] encouraged to do so by my team members, just count as long as they'll let us count.

[00:15:34] Looking back, we actually got a total of 24 minutes, more than twice what the Soviets wanted us to do.

[00:15:41] So were you able to reveal secret Soviet technology when you did that? Is the

[00:15:47] germanium detector that good? The germanium detector is very good and you can resolve many

[00:15:54] of the individual gamma ray emissions and that can allow you to kind of, well, to do several

[00:16:01] things. One is the age of the plutonium when it was separated by the ratios of different lines

[00:16:09] from different isotopes because the plutonium 241 decays to americium 241, so there's a bit of a clock.

[00:16:19] And the isotopic composition of the materials which in the Soviet Union was an official secret.

[00:16:26] So the US did not, we did not consider the isotopic composition of our plutonium necessarily

[00:16:35] as classified information but in the Soviet Union and I think it remains in Russia classified.

[00:16:42] I don't know why, I don't know why it's a secret. But then you also can learn something about

[00:16:50] the amount of plutonium or enriched uranium and that's I think not a great secret because

[00:17:01] it's known roughly how much plutonium it takes to make a nuclear pit.

[00:17:06] Would it matter if you knew specifically how much plutonium was in a Soviet weapon?

[00:17:12] Well, I had long maintained that this was not really that sensitive because

[00:17:17] we know already about how much. But there were people, this was still the Cold War and there

[00:17:23] were people who said no, there is militarily significant information. If you have an estimate

[00:17:30] of how much plutonium Russia or the United States has produced then knowing how much is in a

[00:17:36] warhead that can reveal something about how many warheads you could have. Also it could reveal

[00:17:42] something about the vulnerability of a warhead to certain missile defenses because in the old days,

[00:17:50] the Soviet Union had a nuclear anti-ballistic missile system that would defend Moscow with

[00:17:57] nuclear explosions. And so knowing how much nuclear material is in a warhead can indicate

[00:18:06] something about how vulnerable it is to missile defenses, nuclear missile defenses.

[00:18:12] I think the bigger concerns though were about details of the design and that is much harder

[00:18:20] to learn about through these kinds of measurements but by looking at how different

[00:18:28] emissions at different energies from the same isotope are preferentially absorbed, you can

[00:18:35] learn something about the materials that are between the plutonium or the enriched uranium

[00:18:42] and the detector. You know they're steel because that's the outer shell. Right.

[00:18:46] And so you can figure out what's between the pit and the steel. Exactly. I mean,

[00:18:51] is that that big of a deal though? Well again, I think that for countries that already know how

[00:18:57] to make nuclear weapons this is not such a great secret. That's what I was going to ask.

[00:19:03] The US already knows how to make a weapon. The Soviets already know how to make a weapon.

[00:19:08] So I guess that's my question. Right, right.

[00:19:11] Would anything that you learn allow you to defeat the weapon? No, not that I can see.

[00:19:18] But I guess if you didn't understand what you and your group were measuring,

[00:19:22] you could be in fear that it would. Yeah or suppose you had thought of

[00:19:27] a design concept that your adversary had not, something that was more advanced,

[00:19:34] one that allowed a more efficient design that got a higher yield out of a given amount of material

[00:19:41] or allowed a smaller device. That would be considered especially in the 1980s that would

[00:19:47] have been considered to be militarily sensitive. Okay. Now the US weapons though generally had a,

[00:19:54] were smaller, had a higher yield to weight ratio, were more optimized than the Soviet weapons.

[00:20:03] But some people would say, oh, we couldn't allow our weapons to be subject to such measurements

[00:20:10] because they would show the Soviets how to. And I always thought that was silly that

[00:20:16] the Soviet scientists knew perfectly well how to design nuclear weapons of all shapes and

[00:20:22] sizes and yields. And if they chose to make theirs a little more large and robust, it was probably

[00:20:28] a design decision, a deliberate decision they made, not some lack of knowledge.

[00:20:34] Right. You make this conclusion in the paper that you can't determine if it's a warhead or not

[00:20:41] based on just count rate, but that you need to look at the actual lines. And why is that?

[00:20:48] In order to determine that it contains plutonium or a certain amount of plutonium,

[00:20:52] which most people were thinking that would be the signature characteristic,

[00:20:58] a distinctive attribute of a nuclear weapon is that it has a certain minimum amount of plutonium.

[00:21:05] And so by looking at those distinctive gamma ray emissions that occur only

[00:21:12] from certain isotopes of plutonium like plutonium 239, you can say it is definitely plutonium.

[00:21:19] And you can get a rough idea of how much plutonium you can say,

[00:21:24] is it more than, say, a few kilograms, which is what you need for a nuclear weapon.

[00:21:32] If it was just a gross count rate, it could be any radioactive source.

[00:21:37] Is it harder then to measure the gamma ray lines than just to measure a gross count rate?

[00:21:42] Yes, especially to this high resolution.

[00:21:45] What's the probability that people are incorporating these germanium detectors as opposed to just a

[00:21:53] simple Geiger counter that would count rates?

[00:21:56] I think it's unlikely now in the START treaty and then the NEW START treaty,

[00:22:02] there was a question about, well, how do we know that an object is a nuclear weapon?

[00:22:08] And they decided to use neutrons rather than gamma rays.

[00:22:11] And neutrons again are fairly distinctive because there aren't very many

[00:22:17] substances that emit neutrons.

[00:22:19] Plutonium is a pretty powerful neutron source, particularly plutonium 240,

[00:22:24] which is the second most abundant isotope in plutonium

[00:22:29] that's produced in a nuclear reactor.

[00:22:32] They chose neutrons because it didn't give any design information.

[00:22:38] They basically said, well, we'll assume that if an object is not a nuclear weapon,

[00:22:44] it doesn't emit neutrons.

[00:22:46] And so in the START inspections, when they count the warheads on a missile,

[00:22:52] inspectors actually go and can ask to see the top of a missile.

[00:22:57] And they can count the number of warheads, except we may want to protect certain information and

[00:23:04] put a drape over the top.

[00:23:07] And there may be things other than a warhead like a package of countermeasures or decoys

[00:23:13] or penetration aids that may occupy one of the spaces on top of a missile.

[00:23:19] And so they use a neutron detector.

[00:23:22] The actual warheads will produce a neutron signal.

[00:23:26] But if it's not a warhead, if it's one of these other objects,

[00:23:30] even though it may look pointy, it won't have a signature.

[00:23:35] So the neutron detector is how this problem was solved in practice in New START.

[00:23:42] So then why do the gamma rays?

[00:23:46] Well, that is a good question.

[00:23:48] One of the reasons is it was thought that we might enter into new types of agreements

[00:23:56] that rather than simply count a warhead, we would want to verify it was a particular type of warhead

[00:24:03] or verify that a particular type of warhead had been dismantled.

[00:24:09] And so one of the concepts that we and others were investigating is the idea of a template

[00:24:15] that you could say go into the field and select a warhead at random from a Minuteman missile

[00:24:23] or a Soviet missile, and then take the gamma ray signature, which is very distinctive, very unique.

[00:24:32] No other warhead, no other type of warhead would produce that pattern of gamma ray emissions

[00:24:39] and that you could use that as a template then for other warheads,

[00:24:45] that when other warheads were delivered maybe to be dismantled at a dismantling facility,

[00:24:51] you could do that same measurement and say, oh, it matches.

[00:24:56] It's a W78 or it doesn't match and it's something else.

[00:25:02] That makes more sense.

[00:25:03] It does and it actually works quite well. The US uses these systems internally

[00:25:09] to identify its warheads and its components, but there's great concern about the sensitivity,

[00:25:16] about sensitive information being revealed. And so when we've built such systems, like during

[00:25:26] the early or mid 1990s, there was a lot of cooperation, lab-to-lab cooperation between

[00:25:33] the Department of Energy Laboratories and Russian Laboratories. They used either low-resolution detectors,

[00:25:40] gamma ray detectors like sodium iodide that don't have the high resolution

[00:25:46] or neutron detectors and often went to criteria that were much more relaxed,

[00:25:53] like for confirming that the material that's stored in a facility that was built

[00:26:00] using US funds to store pits, it was decided that we would just confirm that it had at least

[00:26:08] a certain amount of plutonium using neutron measurements. Again partly because of concerns that

[00:26:14] high resolution gamma ray measurements would reveal too much information.

[00:26:18] So your measurement was too good?

[00:26:20] Yes, too good.

[00:26:21] So you did reveal one thing about the Soviet missile, which was what type of uranium they were using.

[00:26:32] Yes, that they had used reprocessed uranium. And this was one of the things they considered secret.

[00:26:40] In the United States it was known that we used reprocessed high-enriched uranium that had been

[00:26:45] reactor fuel. So for example the uranium that's used in US nuclear submarine reactors is high-enriched

[00:26:53] uranium. When it's discharged at the end of the core life, it still is high-enriched. It's

[00:27:00] about 50% still enriched and the US was reprocessing that. But in the reactor other uranium isotopes

[00:27:10] in particular U-232 build up and the U-232 has a powerful high-energy gamma ray emission.

[00:27:20] And we detected that quite distinctly and we could estimate what percentage of the

[00:27:28] HEU was uranium-232. Were you surprised by that or you kind of expected it because the US was

[00:27:35] using the reprocessed fuel? I didn't expect it. It was only after measuring it and determining that

[00:27:42] there was really no other source that we realized what it was. And then I think only at that point

[00:27:50] realized that the US also had been reprocessing HEU and our uranium also would be contaminated with

[00:27:57] that same, which is actually not a bad thing because it makes HEU far more detectable than

[00:28:04] otherwise would be because U-232 being a light isotope is preferentially enriched in the enrichment

[00:28:13] process. And mostly U-235, which is the main isotope in HEU, has a very weak gamma emission.

[00:28:22] The main emission I think is 187 keV and that's very easily shielded. But this 2.6 MeV gamma

[00:28:31] ray, that's hard to shield. Very much so. Easy to detect. And so I think that if you're worried,

[00:28:39] for example, as many of us became later on about nuclear material that had become vulnerable

[00:28:48] to theft or diversion, there were several cases of HEU, I think 20 overall, 20 publicly known

[00:28:57] cases of smuggling of HEU from the former Soviet Union. It was a bit reassuring to know that it

[00:29:06] was contaminated, likely contaminated in this way and that would be more detectable.

[00:29:11] That is good to know. And you knew that because of this experiment?

[00:29:14] I'm sure that the US government, US intelligence, they had come close to,

[00:29:22] in other ways, to Soviet nuclear weapons. They probably had made their own measurements.

[00:29:28] But of course I don't know about any of that. So I don't know whether we truly,

[00:29:33] I doubt that we truly discovered this? Well, but this is all unclassified. So it can enter

[00:29:39] the public discourse, which is very different than whatever's behind the wall. So you have one

[00:29:45] line that you didn't identify, the 1942.7 line. Did you ever identify that?

[00:29:53] No, I had even forgotten that was the case. Oh, I thought maybe you were still trying to

[00:29:57] figure it out. No, although I should ask a person at Idaho who I recently participated in a

[00:30:05] UNIDIR, the UN Disarmament Research Institute had conducted an experiment or a demonstration

[00:30:15] of trying to verify the absence of nuclear weapons on a base. And there was a person from Idaho

[00:30:22] National Laboratory there and he asked me about the Black Sea experiment. And I just,

[00:30:28] I provided the raw data to him. So I should ask whether, now that you've reminded me about

[00:30:33] that line, I should ask, did you identify that? I think we mentioned, I used three curve

[00:30:40] fitting programs just to see including one that I wrote. So maybe it was a flaw, the curve fitting.

[00:30:46] I don't know. I do gamma ray spectroscopy and we have a background line in 1942.

[00:30:51] Oh, what is that? I'm going to look it up for you.

[00:30:55] I left that last part in for all the nukes listening and knew I had to include a follow-up

[00:31:00] because if like me, you needed to know where that 1942 line came from. This line does show up in all

[00:31:07] the data I took at Kentucky so it is a background line, although we also never identified the source.

[00:31:14] So Steve and I emailed back and forth and I think we're pretty sure that it is a calcium line.

[00:31:20] The most abundant is calcium 40. Although it has a low NGEM across section, it can capture

[00:31:26] a neutron resulting in calcium 41, which has a strong gamma ray at 1942.7 keV, an exact match to

[00:31:35] the background line in their spectrum. What can you tell me about the Soviet experiments?

[00:31:42] Because those were different. Karchitov was the main nuclear laboratory in Moscow and it was the

[00:31:53] predecessor to the two arzimus and jelly-bents labs that moved out of the city. And Volokhov

[00:32:01] later became head of the Karchitov Institute. So they had a neutron detector they could fly around

[00:32:08] in a helicopter and had been using it to spy on American ships. And this helicopter comes

[00:32:17] flying by at about 100 meters above the ship and records a signal from the plutonium in the warhead.

[00:32:26] Later, a bunch of us are in Moscow and go to the Karchitov Institute and they tell us more

[00:32:34] about this device they had built. They had pictures of American sailors looking up at their

[00:32:41] helicopter. They were that close. The US had mounted on some ships, anti-submarine

[00:32:51] gopitas, that they could launch from the surface ship nuclear warhead on it. The Soviets could see

[00:32:57] those. They claimed they could see warheads in an aircraft carrier but they couldn't count

[00:33:05] because they'd be bored below deck. But it'd still be useful to know if they existed on the

[00:33:11] aircraft carrier. Yeah, all right. So they could detect warheads with that. The rest of the Soviet

[00:33:18] experiments were inferior. They had the Institute of Physics of the Earth which was doing this,

[00:33:26] we were doing the seismic work with them. They came with a truck full of sodium iodide

[00:33:34] crystal detectors. So they just put the truck on a ship and sail the ship by the

[00:33:42] and they could detect the ship because the gamma rays from the cobalt in the ship

[00:33:49] steel or the ship but they couldn't see the warhead. Then the Vrnadsky Institute brought

[00:33:55] their gamma ray spectrometer. This was essentially a detector at the bottom of a tube that allowed

[00:34:04] them to shield the detector from all directions except where the tube was looking and I think

[00:34:11] that's the one that probably led the head of that institute to tell Velikoff he could see

[00:34:18] things a mile away. They left it on shore. They couldn't see the warhead on the ship which was

[00:34:26] in the harbor good way some shore. So that didn't pan out. Now they also brought sodium iodide

[00:34:34] detectors which just didn't have the resolution, you know, the detector warhead but didn't have

[00:34:42] the resolution to tell them anything and I think they had a germanium detector that was not as

[00:34:48] good as the Princeton Gamma Tag instrument. So they had one instrument that was really excellent

[00:34:56] flown in this helicopter that would detect neutrons and we had one really good instrument

[00:35:01] to detect the gamma ray spectra. Were there any additional experiments after this one

[00:35:07] or was this kind of the end? That was the end. What happened next was we still had the Seismic

[00:35:14] Program operating. The Scripps team felt like they'd collected about all the data they needed to

[00:35:21] collect from the three sites and they were interested in moving the sites to other areas

[00:35:28] of the Soviet Union and we were negotiating with the Institute of Physics of the Earth to do that.

[00:35:37] About the same time, we had done what we needed to do and we were ready to turn it over to the

[00:35:44] government and Chris Payne who was then working for Ted Kennedy, Chris had been on his part

[00:35:52] of the FAS group, he had been with us from the beginning. He wrote some legislation that has

[00:36:01] effectively turned over our project to the Air Force. Now the Air Force is the federal agency

[00:36:10] in charge of seismic monitoring worldwide for nuclear testing. So in effect,

[00:36:18] the Air Force began funding Scripps instead of NRDC funding Scripps.

[00:36:25] Good. It was all done very quietly so nobody knew that the Air Force was taking over the NRDC

[00:36:32] project but that's what happened and then at some point Scripps I guess finished their work.

[00:36:40] So that sort of closed things out. Do you think maybe there's a lesson learned?

[00:36:46] One of my recommendations to people who are still in the business and working,

[00:36:51] you know spend 95% of your time on your day job but take 5% of your time and try to change the world.

[00:37:00] 9 out of 10 of those will fail but if you can hit just one keep trying these far out

[00:37:08] chances it's great potential return. Give it a shot just spend 5-10% of your time

[00:37:16] going after the big things internationally. Well Tom we thank you for going after the big

[00:37:22] things you've made a difference in the world. What is the moral of the story from the Black Sea

[00:37:28] experiment? That actually didn't deliver any results unlike the seismic. It was another

[00:37:34] example of openness on the part of the Soviet Union but I think it maybe another it didn't

[00:37:42] have much impact. I don't think the US still didn't want to include the nuclear arms,

[00:37:48] sea launch cruise missiles in the Star Treaty and in the end what they did was they said we'll

[00:37:54] tell you how many we have. Annually we'll send you a number and you'll just have to trust us

[00:38:03] and at that point the Soviets accepted that. But you were able to prove that you could verify

[00:38:10] a warhead from just an empty missile. It was a real missile in the tube but yes

[00:38:18] but this this has never been implemented in any kind of arms control agreement

[00:38:24] and I think the Soviet approach the neutron detection was a much more plausible one. Well

[00:38:29] I think actually the method is an issue in the verification of the Star Treaty.

[00:38:35] How do you know how many warheads there are on a missile? That requires on-site

[00:38:42] inspection and when that happens the US and probably Russia put a cover over the warheads

[00:38:50] but they can measure bumps. See whether there are neutrons coming out of which bumps

[00:38:58] on the on-site verification. That's with neutron detector.

[00:39:03] So what do you think people cite the Black Sea experiment as so important in nuclear verification?

[00:39:09] Well it was a landmark. It was the only time that a country has measured and published

[00:39:19] the gamma spectrum from another country's warhead.

[00:39:24] It is remarkable. Within the arms control community it's famous but

[00:39:29] but it didn't have an impact on arms control.

[00:39:34] Looking back how was that influenced your career? Like how was it to be there at that time?

[00:39:39] Well you know it was very exciting I was young. I guess I didn't appreciate how special all of

[00:39:47] that was. I was too young to know how. Of course. And that was a unique moment in history where

[00:39:56] the Soviet Union was undergoing this transformation and then soon you know a collapse.

[00:40:03] The strain of that was just too great for the system to bear. In fact I hold out hope.

[00:40:10] I think maybe what I've really learned is that things can change dramatically,

[00:40:14] very quickly for the good. Maybe as well as the bad. But right now we're going through

[00:40:19] rather discouraging times in this field, in the field of nuclear weapons and arms control

[00:40:27] with the Russian invasion of Ukraine, the suspension of Russia's compliance with

[00:40:33] New START, the decision just last week by the Russian Duma to unratify the Comprehensive

[00:40:39] Test Ban Treaty, the buildup of nuclear forces by China, the continued missile testing by North

[00:40:47] Korea, the inability to reinstate the Joint Comprehensive Plan of Action with Iran.

[00:40:55] So there's just so much that is negative and when people myself or students become discouraged

[00:41:04] sort of bordering on hopeless, I like to remind them in 1985 things looked very bleak.

[00:41:10] Or 1983 there was a Reagan administration official talking about the need to be prepared to fight

[00:41:16] and win a nuclear war that with enough shovels we were going to get through it. Oh my gosh.

[00:41:22] And just in a few years that all changed. You were sitting on top of a Soviet missile.

[00:41:29] Yes. And so I like to remind people using that incident that things can change very quickly and

[00:41:37] that we really need to be prepared to take advantage of those opportunities when they arise.

[00:41:47] Thank you for listening and a special thanks to Tom and his many pictures of the Black Sea

[00:41:51] experiment. Frang for his hospitality at Princeton, Steve for meeting me in London. It was a real

[00:41:56] hardship. And the Stanley Center for Peace and Security for sponsoring this episode.

[00:42:01] You can find more information on the podcast website, MyNuclearLife.com.

[00:42:06] Until next time, I'm Shelly Lesher and this has been My Nuclear Life.