Monju (CIS:GO JAPAN) / page 2

Subj: Monju goes critical
To: Wesley Neff, 73042,2455
Date: Wednesday, 6. April 1994 17:01:23
From: Joe Wein, 100142,3715

>>Monju sound like a much worse idea than I feared, the type of thinking that comes out of a late night drunken koenkai of 70's generation LDP hawks swaggering around the more seedy parts of Shinjuku.<<

The whole technology is a nightmare. Until recently I still had some hope the Japanese would have made less of a mess of it than it already is, but now it seems I was mistaken.

I read in today's Japan Times that in the earlier Joyo FBR prototype in Orai, Ibaraki-ken, the cooling pipes had been enclosed inside larger pipes to reduce the risk of a catastrophic leak in case of a crack in the cooling pipes (say, due to an earthquake). In an LWR when such a pipe bursts, an emergency core cooling system (ECCS) is supposed to cool down the reactor by quickly pumping large amounts of cooling water into the reactor core. Because the Monju FBR uses sodium instead of water as a coolant it doesn't have such an independent emergency cooling system. For that reason preventing a cooling pipe rupture is critically important for the safety of the reactor. Without adequate cooling the FBR fuel can deform which can prevent the braking rods from being deployed as well as leading to local supercriticality that can destroy the reactor core and even lead to a minor nuclear blast.

Yet according to the paper the designers chose not to use these double pipes to save costs. Even without those safety pipes the damn' thing already cost $6 billion so they had to cut costs somewhere. And the walls of the main cooling pipes are only 9.5-11 mm thick (0.4 inches), versus 69-78 mm (3 inches) in a LWR. I guess they were only thinking of the steam pressure of cooling water in an LWR that they wouldn't have to worry about (since the sodium is not *supposed* to be heated beyond its boiling point). The fact that the thermal strain of starting up and shutting down the reactor (refuelling, maintenace, etc) over the years leads to small fissures in the stainless steel pipes is even more dangerous because of the thinner walls and higher coolant temperatures seems to have been largely ignored. Various LWRs have had to have their rather more robust main cooling pipes relaced after a few years of service because of such cracks.

The absence of an ECCS in Monju is very worrying, yet the need to have to use sodium for cooling (which can carry away a lot less heat than water) makes it inherently more difficult to design an efficient ECCS to prevent supercriticality or a meltdown or in case of a major problem with the normal cooling system.

This whole design is a mess and they know it. I also read they've just postponed their next generation of FBR from a date in the late 1990s to at least 2005. Time to maybe rethink this whole business I'd say. At the same time they talked about getting costs for the successor down to $4 billion. Have you ever heard of projects this size getting any cheaper? Who do they think they're kidding?

I just hope that the current moves to eradicate political corruption (especially from construction companies) will in due course remove the only reason to built Fast Breeder Reactors in Japan.


Subj: Monju goes critical
To: Wesley Neff, 73042,2455
Data: Wednesday, 6. April 1994 17:01:24
From: Joe Wein, 100142,3715

>>How close in your view is Japan to a nuclear weapons program?<<

The biggest obstacle for all NPT dodgers has always been to set up a reprocessing plant to extract Plutonium or alternatively (if you haven't got enough nuclear waste), to build an enrichment facility to enrich natural Uranium to weapons grade. Japan already has access to hundreds of kgs of fully extracted Pu from its contracts with British Nuclear Fuels in Sellafield/UK (which handles the waste from its 43 Light Water Reactors). The fuel used in Monju is 1500 kg of a mixture of that Pu and weapons grade Uranium (I'm not sure whether they bought that or made it themselves). Either would do for the bomb right now, but the Uranium and future blanket Pu produced in Monju would make for a more powerful weapon. That's one major problem out of the way.

The remaining step is to get a detonating mechanism (high performance conventional explosives plus precision detonators) together, plus some necessary calculations on the optimal geometry of the subcritical masses of Uranium / Plutonium that need to be joined up to cause the blast. The Manhattan project scientists took a couple of months using a then brand new computer that was much slower than any modern day programmable scientific calculator. On a modern PC the longest delay would be to write the program that does the calculations. The precision detonators that Irak bought for its bomb came from the US and where intercepted at Heathrow Airport in the UK. I wouldn't bet on the US intercepting any detonators going to Japan. I'm not an expert on these triggers, there may even be Japanese companies that can make them.

Mechanically putting the bomb together is no problem for Japan (not too different from making fuel elements for Monju). After that, all that's left before officially becoming a nuclear power is a test blast and I'm not sure where Japan could carry it out, maybe they'd sacrifice one of their smaller Pacific islands. I think six months to a year (don't forget the ministerial paperwork ) is quite a realistic estimate.


Subj: Monju goes critical
To: Joe Wein, 100142,3715
Date: Thursday, 7. April 1994 10:07:05
From: Hiroyuki Sato, 71461,2100


Isn't it easier to buy a nuclear device from now begone USSR than Japan to start the program? What is the sense of possessing nuclear weapons for Japan?

Your quotation from Japan Times was interesting. And now I believe they shouldn't have started this junk. But did US nuclear committee intervened? A friend of mine who actually worked on the sodium coolant in nuclear reactor at Argone National Laboratory in IL explained to me why sodium is safer than water. And the article sounded just picked up only deadly cons instead of citing both pros and cons regarding use of sodium versus water. I'd better call up my buddy and ask him again I think I am just a g.. d.. scientist

BTW Joe. Since you are in Japan, what is the reaction of the people regarding Monju? I know Japanese people are more sensitive to this type of issue than anybody else, as I understand.



Subj: Monju goes critical
To: Hiroyuki Sato, 71461,2100
Date: Thursday, 7. April 1994 16:11:16
From: Joe Wein, 100142,3715

>>Isn't it easier to buy a nuclear device from now begone USSR than Japan to start the program?<<

It may be easier, but Japan likes to reinvent the wheel, as they did in the case of the economically insane Japanese space program. I think they'd build it themselves, just as a matter of national pride. They have developed too much expensive nuclear know-how for simply buying a stolen Russian warhead just like any miserable middle-east dictator would...

>>What is the sense of possessing nuclear weapons for Japan?<<

What is the sense of Britain possessing nuclear weapons? They got most of the technology through their cooperation with the US, they have been testing them in Nevada ever since they stopped testing in Australia and they would have to use US missiles to launch them from submarines. Britain is even a full member of NATO and hence protected by the US nuclear shield anyway. Beats me! Yet the government has been raving mad about left-wing Labour's call for giving up independent British nukes. There is no rational reason why Britain and France should need nuclear weapons yet Germany, Italy and Japan do not. I'd personally prefer fewer nuclear powers, not more, and if only America had them on behalf of all democratic countries, fine by me.

I am not convinced at this stage that the Japanese government has any intention to become a nuclear power within the foreseeable future. The fact that they could make a bomb any time doesn't prove their will to do so. In 1955, long before there was sufficient knowledge about the technology and its safety and economy, the Japanese goverment chose to aim for generating the majority of its electricity from nuclear power. Monju was ultimately the result of that decision. The fact that the government bureaucracy has been unable to reevaluate its now clearly unwise 39 year old choice testifies to bureaucratic lethargy, lack of outside democratic input and pressures from corrupt money politics.

>>A friend of mine who actually worked on the sodium coolant in nuclear reactor at Argone National Laboratory in IL explained to me why sodium is safer than water.<<

I'd be very interested to hear more details on that. Sodium is a necessary evil in an FBR not a substance of choice. There is simply no other material that survives the high temperatures while absorbing relatively few fast neutrons, remains liquid in the necessary temperature range, carries enough heat and doesn't react much with the fuel rods or cooling pipes. In almost every other respect, Sodium is a pain in the *** to use.

Sodium is not only burnable and once on fire can't be extinguished with either water, carbondioxide or halon, it reacts violently with water creating large amounts of explosive hydrogen gas (the kind of gas that blew a hole into the outside of the Chernobyl reactor).

If allowed to cool off below 98 Centigrade it solidifies and, like water/ice expands in the process, bursting the cooling pipes, just like a car radiator without antifreeze in sub-zero temperatures. At temperatures where it is liquid it spontanuously catches fire when in contact with air, so it permanently has to be surrounded by inert nitrogen or argon. In Monju only the sodium in the primary cooling cycle meets that requirement, a leak in the secondary cooling cycle would start a fire quicker than a car fuel pipe leaking onto a red hot exhaust manifold in a car. I'm not sure what kind of fire extinguishing systems they employ around that part of Monju, they better be good ones.

Refueling an FBR is a special problem since for that the nitrogen filled containment has to be opened to admit fresh fuel while the sodium has to be kept heated... How would you feel about your car radiator being filled with petrol (gasoline) instead of water and having to top up the radiator while the engine was running?

While water can't stand the heat of an FBR, slows down fast neutrons, reacts with metals at high temperatures, its excellent specific heat capacity makes it an efficient coolant, it doesn't burn or explode and is generally considered safe enough to drink, at least before it's spent some time in a nuclear installation.

In a LWR that overheats steam bubbles that form will automatically stop the chain reaction. That makes LWRs inherently safer than FBRs that simply escalate energy output further in that case.

>>But did US nuclear committee intervened?<<

I understand that in the US it is now a basic safety requirement for reactors that a coolant void (coolant leak or vapour from overheating in the reactor core) in itself has to reduce criticality in the reactor. A sodium cooled FBR like Monju (or incidentally the Chernobyl accident reactor) doesn't meet that condition.

In addition, US safety standards for radioactive Iodine and radioactive noble gas emissions such as Krypton and Xenon are such that they can't be met by existing technology. A nuclear reprocessing plant such as in Sellafield (UK), Cap La Hague (France) or the Japanese one under construction in Aomori-ken could never meet US safety standards.

Because of that, in the US direct storage now looks like the best method of nuclear waste disposal. The US investigated storage in underground salt domes but abandandoned that idea because of several serious problems. Yet that is exactly the technology Germany is thinking of using.

Countries with a nuclear industry usually have very little interest in exposing safety risks in other nuclear countries' technology, to such an extent that prior to the Chernobyl disaster Western experts had even praised certain 'inherent safety features' in the Russian RMBK design, while of course now they are distancing themselves from that design and naturally "that kind of accident could never happen here!" For weeks and months the IAEA and its director, Hans Blix, downplayed the seriousness of the Chernobyl accident until publications from within the USSR proved the contrary.

All these countries would have good reasons to call for nuclear installations in other countries be shut down on safety grounds. The likely result would be a shutdown of all installations in all countries. Therefore they prefer to keep silent -- until another major accident like Chernobyl happens.

>>BTW Joe. Since you are in Japan, what is the reaction of the people regarding Monju? I know Japanese people are more sensitive to this type of issue than anybody else, as I understand.<<

I don't have so many Japanese friends yet. But I noticed that the reactor startup and the discussion surrounding it has been widely publicised by TV and newspapers. Both official voices and opponents have been given a chance to make their points. I do think generally Japanese are sensitive to nuclear issues only as far as bombs are concerned. The population seems to have tolerated a very pro-nuclear energy policy that is second to none but of France. Of all the major parties I think only the socialists have a clear anti-nuclear energy policy.

I think the Japanese government has been very smart, managing to sell this policy as energy self-sufficiency when for economical and other practical reasons it can't be. Currently Japan depends virtually 100% on imports for energy (except hydroelectric power and solar energy for domestic hot water). During WW2 a shortage of energy supplies was one of Japan's most serious problems (hence the occupation of Dutch-East India / Indonesia), and even today Japan depends more on oil from the Middle East than do Europe or the US, hence the fear of shortages.

That makes it comparably easy to sell fast breeders to voters who generally don't know much about the risks of the technology other than the possible nuclear proliferation. Japan is an island country and few Japanese have extensive foreign contacts. That makes it easy to convince Japanese that nihon is somehow fundamentally different from gaikoku. Being the only country that uses fast breeders is more of a mark of distinction than a reason to stop and wonder. I just hope it won't take a major accident to demonstrate that unfortunately the laws of physics are the same in Japan as they are elsewhere.


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