Subj: Monju goes critical
To: Joe Wein, 100142,3715
Date: Thursday, 7. April 1994 16:12:23
From: TAKEO SHIGEMOTO, 100201,444
Hi Joe (and everyone here),
I, as one Japanese, have to argue against you.
As you know some Japanese are against Monju(not only Monju but also all nuclear facilities), but most of them are only worrying about their safety. And most Japanese never think Japan will built any kind of nuclear weapon! I believe this is a kind of Japanese national policy, based on the experience of Hiroshima and Nagasaki.
I want everyone here to know this fact.
And I think there are some misunderstanding about Japanese Plutonium.
In fact Japan has about 1.6 ton of Plutonium, but it is nuclear fuel grade, that is, the content of Pu239 is less than 70% and it is not enough to build nuclear bombs. Nuclear fuel grade Plutonium contains a lot of Pu240 which easily starts nuclear fission, so it is difficult to build nuclear weapon by using the fuel grade Plutonium.
The weapon grade Plutonium contains more than 93% of Pu239, but there are no established technology in the world to extract Pu239 from the fuel grade Plutonium mixture. Nuclear armed countries are making Pu239 directly from Uranium by using the gas cooling reactor.
After all Japan can't build any nuclear weapons by using the Plutonium in Japan.
Finally I will show you some comments by the IAEA(International Atomic Energy Agency). The IAEA keep watching a nuclear reprocessing plant in Tokai-mura 24 hours every day, and investigate all the nuclear power plants in Japan every two months. About these investigations they say, "There is no problem".
And a high official of the IAEA in Vienna said, "Japan has been giving all-out support to our operations. Their policy on nuclear is consistent. There is no doubt Japan diverts any nuclear materials to some other purpose. We have never pointed out the possibility at any places, officially nor privately. The media are only talking about the quantity of Japanese Plutonium, but they don't know the quality. We think their reports are unfair".
I hope you know these fact and make discussion on them.
Takeo Shigemoto
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CS:100201,444
INET:ts4q+@andrew.cmu.edu
Subj: Monju goes critical
To: TAKEO SHIGEMOTO, 100201,444
Date: Thursday, 7. April 1994 17:27:27
From: Joe Wein, 100142,3715
>>I, as one Japanese, have to argue against you.<<
I welcome some more Japanese input here. After all this forum is about your country!
>>And I think there are some misunderstanding about Japanese Plutonium.
In fact Japan has about 1.6 ton of Plutonium, but it is nuclear fuel grade, that is, the content of Pu239 is less than 70% and it is not enough to build nuclear bombs. Nuclear fuel grade Plutonium contains a lot of Pu240 which easily starts nuclear fission, so it is difficult to build nuclear weapon by using the fuel grade Plutonium.<<
Well, that's what the nuclear industry has claimed for decades until in the late 1970s US President Jimmy Carter proved them wrong. I know that high grade military Pu is made by keeping the fuel in the reactor for only fairly short periods, thereby cutting down on heavier Pu isotopes that you don't want for the bomb. Just because Pu extracted from commercial nuclear waste is lower in Pu239 doesn't automatically mean you can't build a bomb with it, yet for decades that very same claim was made by the nuclear electricity lobby, without anyone ever having tried and proved one way or another!
Carter, who had been a nuclear technician at some point in his career took more of an interest in the problems of nuclear arms proliferation than his predecessors did. He finally commissioned a study and ordered a nuclear warhead to be constructed from Plutonium from commercial Light Water Reactors like the ones in use in Japan. That warhead was built and successfully tested under the Nevada Test Site where all US nuclear weapons tests are carried out. Light water reactor Pu is less optimal and the yield of the bomb was smaller than that of normal nuclear warheads but it certainly worked. Based on this knowledge the US government then discouraged both nuclear reprocessing and Fast Breeder Reactors in the US.
Anyone still claiming today that light water reactor Pu is unsuitable for building a bomb is obviously ill informed about the problem. You only called it "difficult", not impossible. Well, building Monju was difficult too, wasn't it?
In any case, once Monju actually starts breeding that will be a mute point since the Pu coming out of Monju will be high grade Pu239 with little Pu240 mixed in. If Monju works satisfactorily then burning that 1.6 tons of low grade Pu in its core will yield about 2 tons of high grade Pu, enough for about 200-400 warheads. Diluted and used as lightwater reactor fuel and ignoring reprocessing and fuel element construction costs that Pu will save importing enough Uranium to recover about 0.5% of Monju's construction costs.
As to the statements by the IAEA, these are the same guys who supervised Israel while it was working on its nuclear weapons. The whole raison d'etre of the IAEA is to support the spread of non-military uses of nuclear technology. They are the last people who'd criticise new technology like Monju because without it they'd basically be out of a job. The IAEA may be an autonomous UN agency, but it is by no means impartial on nuclear matters, as demonstrated by its stance after the Chernobyl accident where the IAEA downplayed the scale of the disaster, afraid the public backlash would bring to a halt all new civilian nuclear projects and with it the need to support the IAEA and its well staffed headquarters in Vienna. And Japan happens to be one of the biggest financial contributors to the UN...
As I stated elsewhere, I don't think Japan is planning to build a bomb and there would be a lot of public resistance to it. Yet Monju would certainly give it the technology, assuming they didn't want to simply start with LWR Pu or enriched Uranium (since, if I'm not mistaken, Japan now has its own enrichment facilities).
Joe
Subj: Monju goes critical
To: TAKEO SHIGEMOTO, 100201,444
Date: Sunday, 10. April 1994 01:28:06
From: Joe Wein, 100142,3715
>>Is it true? Even for separating U235 from the mixture a plant is necessary, it seems more difficult to separate Pu239 from the muixture of Pu239, Pu240 and other isotopes. (though the ratio of U235/U238=0.72:99.275, Pu239/Pu240>70:30)<<
All Uranium isotopes and all Plutonium isotopes chemically behave the same so chemical processes as in a reprocessing plant can only separate U from Pu, but not different isotopes of the same element (U235/U238, Pu239/Pu240). For that you need physical processes.
When natural Uranium is enriched for use as Light Water Reactor (LWR) fuel (5% U235, 95% U238) or weapons grade Uranium (95% U235, 5% U238) the Uranium ore (0.7% U235, 99.3% U238) is first converted into Uraniumhexaflouride (UF(6)) which can be evaporated at low temperatures. That gas is then forced through thin metal membranes or spun in a centrifuge. Since U235 diffuses slightly quicker through membranes and U238 drifts quicker to the outside in a centrifuge, it is possible to gradually separate the two by repeating either of these processes thousands of times. That's what happens at an enrichment plant.
Uranium and Plutonium can relatively easily be separated from each other by the fact that Pu in general is more soluble so some chemicals will dissolve Pu when corresponding Uranium compounds remain as undissolved solids. That's what happens in a reprocessing plant.
In theory it is also possible to separate Pu239 from Pu240 in an enrichment plant, just like Uranium, but in practice it would not be a very smart idea: While Uranium is only mildly radioactive (half life of several millions of years) and isn't absorbed easily by the body, Pu is highly radioactive (half life of only about 24,000 years), very toxic and can be absorbed by many parts of the body, especially the bones and the lung. In either case, between 0,000001g and 0,00004 g of Pu can cause cancer (leukaemia or lung cancer). Turning metallic Pu into a very reactive and volatile gas to separate its isotopes in an enrichment facility would not only immediately contaminate the inside of the enrichment facility with highly toxic Pu (with all the problems of decommissioning the plant at the end of its life), it would also pose a serious risk of PuF(6) gas escaping into the atmosphere through tiny leaks in the enrichment plant, leading to general radioactive contamination of the plant and its environment. For that reason, Pu is never enriched. It's much cheaper and safer to do the same process with fresh Uranium.
Because Fast Breeder Reactor (FBR) fuel currently produced from LWR waste already contains some Pu240, its waste is even richer in Pu240 and therefore it really isn't worth reprocessing again to recover any unused Pu239. For the same reason Pu fuel produced from recycled LWR fuel and reused a second time in LWRs isn't worth reprocessing a second or third time.
What's more, even the Uranium reclaimed from LWR or FBR waste won't be enriched again for use in LWRs. As the chemical Pu extraction in a reprocessing plant is less than perfect (for example, at least 1% of Pu is left in the discarded waste after extraction) some Pu will always contaminate the U, making recycled U almost as risky to use in an enrichment plant as pure Pu (see above). The only possible use of waste Uranium from a reprocessing plant therefore would be for the breeding blanket in an FBR (since there it will quickly be converted into toxic Pu239 anyway).
Reprocessing spent FBR fuel is technically more difficult than spent LWR fuel (FBR waste is similar to the waste from nuclear submarines and that has generally just been stored unprocessed for now), so any unburnt Pu or U left in FBR waste will probably be lost forever. In any case it would probably require a separate (and again expensive) reprocessing plant from LWR fuel. For that reason only the breeding blanket Pu of an FBR is planned to be reprocessed for now.
The so-called "fuel cycle" isn't really a cycle since the fuel doesn't go round and round as the name is meant to suggest. It will go round at most once in most cases. Whether the Monju FBR actually manages to produce more Pu than it uses (the theoretical physical limit for output is only 30% above input anyway) under these circumstances remains to be demonstrated, hopefully without a major accident...
Joe
Subj: Monju goes critical
To: All
Date: Friday, 8. April 1994 20:28:22
From: barrell, 100240,2632
Dear friends,
I've been interested in the Monju and japan's bomb debate which seems to have hotted up since I mentioned the new facility at Tokai a few weeks ago.
Forgive me if you've heard all this before. I know Joe Wein has, and his input has been invaluable to me.
However, now that we've got a wider community concentrating on this one, I'd just like to draw your attention to the new facility being built by the Science and Technology Agency's outfit called "Donen" in Tokai Mura.
It's called the Recycling Engineering Test Facility, and according to the highest levels, the directpr general of the STA. Mr Eda, it *can* be used to extract weapons grade plutonium from the blanket of spent fuel around Monju (and also the experimental Fast Breder known as Joyo.). Now while the current Japanese govenment claims that this will never be used for making nuclear wepon s, that facility will not be in operation for at least three years.
There are two main problems with it: the anti-nuke movement and the media in Japan are reluctant to talk about it as anything special.The media silence I don't understand but the green movemnt is hoist by its own petard. because they made so much fuss about any old uranium/plutonium being a deadly substance that
As to feasibility. Well, the STA, the agency responsible for this program, was kick started way back in the late Fifties by Yasuhiro Nakasone. He is known to favour a nuclear potential for Japan. The other great program the STA has pursued for years is the space rocket, and is proud of the success of the NT2. Why does Japan need an ICBM? The STA runs both programs: FBRs and space rockets, what's the connection?
As to
Anyway. I suggest our japan colleagues ask some questions about what the RETF is doing in Tokai, and why the newspapers don't think it's worth reportin.
Tony
Subj: Monju goes critical
>>Why else would they want to extract high grade plutonium?<<
Because that happens to be what all fast breeder produce. It's in the nature of the beast: The Pu is bred not in the fuel rods like in a LWR or military gas cooled reactor but outside the core where it is relatively easy to swap, before it gets too contaminated by Pu isotopes other than the 239 required for bombs and nuclear fuel. The French built their Superphenix for precisely this reason: It permitted the French armed forced to make bomb Pu at the expense of French electricity consumers.
In LWRs Pu gets bred in fuel rods as a pure side effect of burning Uranium. There you want to leave fuel rods as long as possible so you can use up as much of the expensive enriched Uranium fuel as possible. As a result you get more non-239 Pu isotopes, i.e. low grade Pu. Reprocessing plants later on can't separate Pu isotopes, they can only separate waste into Pu (all kinds), U (both 235 and 238) and junk. The fact that a reprocessing plant that extracts FBR blanked Pu produces high grade Pu is not a design choice in the construction of the reprocessing plant. It is a result of the FBR technology itself!
>>FBRs and space rockets, what's the connection?<<
Well, both were government run high tech prestige projects that (at tax payers expenses) imitated what other countries had already done and ended up as commercial failures. Just like the Americans had to put a man on the moon after the Russian had beaten them with the first man in orbit, without thinking if there was any point.
If the Japanese wanted an ICBM, they wouldn't have to develop something with a 2 ton payload (a Japanese nuke would be considerably lighter) and they would surely not run it on hydrogen fuel which is a b***h to handle. They'd go for solid fuel, hydrazine or at least a kerosene/oxygen combination. If you were to build an ICBM that can hit Pyongyang within five minutes of Tokyo having been wiped out, you wouldn't choose a fuel that permanently needs to be cooled down to -251C to stay liquid. Once you've managed to fuel up the rocket (which takes a loooong time with hydrogen), you got to launch it fairly soon or your fuel will evaporate and the tanks might ice up! Hydrogen has the best payload to rocket weight ratio, therefore that Japanese rocket engine is great for prestigious space programs, especially high orbit space stations and satellites and interplanetary missions, but for military rockets you want quick standby launchability and for that purpose it's actually less suitable than Wernher von Braun's V2 was back in 1944/45!
>>The one that was dropped on Hiroshima wasn't tested. It was a gun assembly bomb using enriched uranium. The scientists knew it would work, and anyway it contained most of the U 238 they had.<<
The Hiroshima bomb was made from U235 not 238. The latter is the junk that you can't use. You're right about the Nagasaki and Alamogordo bombs. And they actually also used up all Pu they had in these two bombs. In those days Pu was brand new stuff and not much was known about its criticality. They did a lot of practical experiments before they could do any calculations for the actual construction. These days all the data is well known. If you can build a fast breeder you basically know how to build a Pu bomb that works.
One interesting fact is that Monju actually runs on a mixture of weapons grade U235 and recycled LWR Pu239. The reason for that is that with only low grade LWR Pu as fuel they couldn't achieve the same breeding rate (i.e. less Pu output per fuel input) than with a more weapons grade fuel for the core. The breeding rate is a significant selling point of the FBR. They absolutely need to achieve over 100% (produce more Pu than they burn Pu+U235) to justify the existence of the FBR, since even LWRs can achieve a breeding rate of 80%, at significantly lower cost. That's another reason for extracting weapons grade Pu from the FBR mantle: If they use weapons grade FBR mantle Pu they'll be able to do away with the expensive weapons grade U235 production.
If the Japanese really built Monju to produce nuclear weapons, they could have saved themselves $6 Billion and a lot of bad publicity by simply using the weapons grade Uranium produced for Monju's core to build a Hiroshima type bomb.
Sorry, you still haven't got me convinced... I still think the biggest danger of Japanese Fast Breeder Reactors and reprocessing plants lie in their accident prone technology, not in the risk of Japan becoming a nuclear power. The real danger of nuclear proliferation comes from third world countries like Pakistan or Iran, especially after China starts exporting nuclear technology to pay for its own nuclear power stations.
Joe
Subj: Monju goes critical
>>In fact Japan has about 1.6 ton of Plutonium, but it is nuclear fuel grade, that is, the content of Pu239 is less than 70% and it is not enough to build nuclear bombs.<<
U.S. Defense Secretary William Perry, according to a Kyodo news agency report, recently stated in a press conference:
"My concern is that a vigorous, robust North Korean nuclear bomb program with delivery systems might make temptations for countries like Japan, South Korea and to Taiwan to go ahead with a nuclear bomb program irresistible."
"There can be no doubt that there are technical capabilities in those countries to do that."
In Japan's case he called a nuclear weapons program a "simple and straightfordward" matter due to its "large quantities of plutonium" from its nuclear energy program.
If anyone in the world knows for sure if plutonium from LWR waste such as the material returned to Japan from Sellafield, UK is usable for building bombs then it is the US Department of Defense, the world's oldest and biggest nuclear weapons builder.
Joe
Subj: Monju goes critical
An interesting bit of news that caught my eyes in the papers today:
Remember when I was talking about the risk of fires in the Japanese Monju plant from sodium leaks in the secondary coolant cycle which (unlike the primary cooling cycle) is not immersed in inert gas (nitrogen)?
This is exactly what happened recently at a Russian sodium cooled fast breeder reactor in Jekaterinburg in the Urals, the worlds second largest FBR after the French Super Phenix. Fire fighters were unable to put out the fire until quite some time and smoke could be seen rising from the reactor building which is 40 km from that major city. According to the IAEA the fire was due to a sodium leak. This is the second such fire to have occured since last October. The plant had actually been shut down for repairs since last month. I wonder if the effects would have been the same if the reactor had been operating under full load at the time.
Naturally the accident had "no influence on the environment", according to official statements...
Joe
To: barrell, 100240,2632
Date: Friday, 8. April 1994 23:47:02
From: Joe Wein, 100142,3715
To: TAKEO SHIGEMOTO, 100201,444
Date: Thursday, 5. May 1994 12:22:07
From: Joe Wein, 100142,3715
To: Hiroyuki Sato, 71461,2100
Date: Monday, 9. May 1994 00:54:26
From: Joe Wein, 100142,3715