The New Improved Nuclear Weapon

 

A debate has been promised parliament this year on the future of our nuclear weapon – whether Trident should be replaced or scrapped.  As an aid to an informed debate, an article in a recent issue (6th July, 2006) of Nature, the prestigious international weekly journal of science, is interesting, being devoted to the future of nuclear weaponry according to those committed to seeing that nuclear weapons have a future.  The article makes rather repulsive reading, being written in a style suited to an intelligent schoolboy fascinated with science, but it does contain much information that appears to be new.  It speaks of the need to replace the ‘ageing’ US stockpile, and of the requirement to build a new generation of weapons that will be so reliable that they will not need to be tested:  the Reliable Replacement Warhead, or RRW. 

In doing so the author Geoff Brumfiel describes in some detail how a modern hydrogen bomb warhead is constructed, in order to explain how it is that nuclear weapons can be said to be ‘ageing’.  Apparently the plutonium in the primary cell emits ‘a small but steady stream of radiation’, and this radiation over time is said to change the properties of the plutonium alloy by altering its crystalline structure, ‘which in turn can cause the weapon to fail’.  This much is stated flatly, as if it were established fact.  We have no way of knowing whether it is, and have to trust that the testing of ‘ageing’ bombs before the moratorium on nuclear testing in 1992 resulted in a tested bomb fizzing instead of exploding. The crystalline alteration cannot be proved to have affected reliability without such hard evidence.[1] (Incidentally, there seems no reason why the failure of a bomb during testing should be kept secret.  Failure would be the only justification for making the new weapon, for which taxpayers are to pay so much.)  Apart from this phase alteration there can hardly be another way that the plutonium becomes unreliable – its life is, in human terms, infinity.  The politicians who must make available billions of dollars of taxpayers’ money must rely upon the advice of the scientists, whose livelihood it is to make nuclear weapons. 

A nuclear metallurgist Siegfried Hecker is quoted as urging that the plutonium in the bombs be melted down and remade.  That is evidently one solution to the alleged problem.  Another is the proposed RRW.  Exact details of the proposed new weapon are of course ‘classified’, but the likely changes to the W76 warhead (an analogue of which is used on our Trident submarines) may include:  1. Adding more plutonium, which is said to increase shelf life.   2.  A ‘classified’ redesign of the plutonium primary, possibly to include casting it rather than fabricating it out of plutonium sheet.  3.  Replacing the beryllium shell with stainless steel ‘to reduce the environmental hazards associated with manufacture’ (an extraordinary statement!).   4. Replacing the existing conventional explosive (which triggers the device) with ‘an insensitive high explosive’, which would be heavier but would ‘decrease the likelihood of an accidental detonation during storage’.

This last claim, that there is a risk of accidental detonation of a hydrogen bomb during storage, relates to an explosion of the conventional explosive only, as the nuclear explosion requires a computer-assisted sequence.  

Not all the experts agree that the new RRW would not need testing, a quality that is its main justification.  Brumfiel quotes a 1994 study by physicists Drell and Peurifoy which ‘showed that rocket fuel, not high explosives, would be the most likely cause of an accidental explosion’.

 

More facts mentioned:

1.  More than $1,400,000,000 is spent every year ‘to look after the         existing US nuclear stockpile’.  This enormous cost would be diminished if the existing stockpile were to be reduced from 10,000 to 2,000.  Such a reduction, which would result in a stockpile that could only destroy the world once, is regarded as pretty risky.

2.     The programme for making the new RRW is looked at favourably by both Republicans and Democrats ‘because it will allow a fresh generation of weapons designers’.  ‘The RRW provides the labs with a fresh challenge and a clear vision.’  So much for US respect for their obligations under the NPT. 

3.     In an editorial in the same issue, the claim is made that ‘Each nation [US, Russia, France, China and Britain] spends several billions of dollars a year to house and maintain their nuclear weapons and train physicists and engineers with weapons expertise’.  Several billions!  Each nation!  Every year!

H D

 


[1] Note:  Testing of bombs to confirm their reliability poses a problem for scientists, in that if the bomb did explode, that would still not be proof that the other ‘ageing’ bombs in the stockpile were reliable – a percentage might not be.  The proper scientific way to establish reliability would be to test every bomb in the arsenal.