In an e-mail to multiple addressees, dated June 29, 2005, I suggested that because of the Bush/Putin handshake, the RRW programs could take advantage of the use of uranium 235, rather than plutonium 239, in the redesigned primaries. The advantages of uranium pits could include the following:
Replacing plutonium pits with uranium pits will eliminate the need for a Modern Pit Facility and a refurbishment of TA-55.
Y-12 has expertise in the fabrication of uranium parts based on 60 years of experience. I suggest that Y-12 can be upgraded to handle the fabrication of uranium pits at a fraction of the cost estimated for a modern pit facility.
The half-life of uranium 235, due to radioactive decay, is 700 million years versus 25,000 years for plutonium 239.
Therefore, the radioactive hazards associated with uranium pit fabrication would be reduced.
The radioactive hazards of weapon handling by DOE and military custodians could be reduced.
Plutonium is pyrophoric. Uranium is not.
With a 700 million year half-life, there should be no pit aging problems.
Given an accident and a uranium spill, decontamination could be less demanding.
The larger critical mass required by the use of uranium will result in thicker pit shells, thereby reducing machining problems during fabrication and resulting in higher yields and lower fabrication costs.
With the use of uranium, perhaps IHE will be less important.
The use of uranium pits will meet the NNSA objectives of a less expensive, easier-to-manufacture, longer-lasting, and less hazardous product.
Maintain 500 Minuteman III ICBMs with 1 URRW RV payload for each missile. The Minuteman III was originally deployed with 3 Mark 12s, and later upgraded to use 3 Mark 12 As. A single RV, the Mark 21, is now planned. The weight of a single URRW RV is less than the total weight of 3 Mark 12 As. There will be no base diameter constraint in using a single URRW RV. Again, NNSA indicates that the Air Force is agreeable.
