I previously read somewhere that nuclear warhead maintenance requires a constant stream of tritium. I wonder if this ‘Fogbank’ is related to tritium?:
PLANS TO refurbish Trident nuclear weapons had to be put on hold because US scientists forgot how to manufacture a component of the warhead, a US congressional investigation has revealed.
The US National Nuclear Security Administration (NNSA) "lost knowledge" of how to make a mysterious but very hazardous material codenamed Fogbank. As a result, the warhead refurbishment programme was put back by at least a year, and racked up an extra $69 million.
According to some critics, the delay could cause major problems for the UK Trident programme, which is very closely tied to the US programme and uses much of the same technology. The US and the UK are trying to refurbish the ageing W76 warheads that tip Trident missiles in order to prolong their life, and ensure they are safe and reliable. This apparently requires that the Fogbank in the warheads is replaced.
Neither the NNSA nor the UK Ministry of Defence would say anything about the nature or function of Fogbank. But it is thought by some weapons experts to be a foam used between the fission and fusion stages of a thermonuclear bomb. US officials have said that manufacturing the material requires a solvent cleaning agent which is "extremely flammable" and "explosive". The process also involves dealing with "toxic materials" hazardous to workers.
...But vital information on how Fogbank was actually made had somehow been mislaid. "NNSA had lost knowledge of how to manufacture the material because it had kept few records of the process when the material was made in the 1980s, and almost all staff with expertise on production had retired or left the agency," the report said.
...To John Ainslie, the co-ordinator of the Scottish Campaign for Nuclear Disarmament, it was "astonishing" that the Fogbank blueprints had been lost. "This is like James Bond destroying his instructions as soon as he has read them," he said. "Perhaps the plans for making Fogbank were so secret that no copies were kept. The British warhead is similar to the American version, and so the problems with Fogbank may delay Aldermaston's plans for renewing or replacing Trident."