Good reports have emerged on questions surrounding the W76 warhead and the Life Extension Programme. It is clear that the most important impact that this will have is further supporting the case for the Reliable Replacement Warhead.
The question revolves around a special non-nuclear material manufactured at Y-12 for the interstage section of a thermonuclear warhead known as “Fogbank”.
There two good primers here from ACW and here from the Scottish CND[click on the word document]
The Scottish CND report states,
… Fogbank is a critical component of the Trident W76 warhead. The design margins of the W76 warhead are so tight that it is unlikely that AWE could produce an alternative secondary with a different design that would fit the constraints of the Mk4 Re-entry Vehicle…
That’s important because remember the tight design constraints are often stated as a rationale for RRW. These constraints can be relaxed by manufacturing warheads with less of an eye being directed toward yield-weight ratios.
The above statement is true but the W76-1 warhead is paired off with the Mk5 RV. If so, the problem with Fogbank could be mitigated by precisely producing an alternative secondary for the W76-1 that may well fit the constraints of the Mk5 RV.
To appreciate the point I am making here one need only take this on board from SIPRI,
… The modernization of the W76 warhead continues with three specific efforts under way. One involves an LE programme that inter alia replaces the arming, firing and fuzing (AF&F) system on the W76/Mk4 re-entry vehicle to add a ground-burst capability that will significantly enhance the lethality of the weapon against harder targets. The modified warhead, which will be called the W76-1, may permit a reduction of the explosive yield. A second effort involves adding the 'accuracy adjunct' to the Mk4 re-entry vehicle to enhance the effectiveness of the W76-1/Mk4 and to enable deployment of conventional warheads on the Trident II (D-5) SLBM. The third effort involves a design incorporating the W76-1 on the larger Mk5 re-entry vehicle normally used for the W88 warhead in order to relax the design constraints required when using the smaller Mk4 re-entry vehicle…
We must be very, very careful when seeing reports on the reliability and so on of warheads like the W76 and the W88 in the current climate. We must avoid getting inadvertently sucked into a pro RRW agenda.