willner%cfa183@harvard.harvard.edu (Steve Willner P-316 x57123) (04/05/89)
From: willner%cfa183@harvard.harvard.edu (Steve Willner P-316 x57123) [In my opinion, most of the speculation on cold fusion is grossly premature, but it seems worthwhile to clarify one aspect of existing fission technology.] Someone wrote: > [in putative cold fusion power] the lack of heat generation from > fission products would eliminate the nuclear sub's biggest silencing > problem: the need to keep reactor cooling going at all times. to which someone else, missing the point, replied: > Just why do you think that fusion plants would run without > generating heat as a fission plant does? The reason fission plants > create heat & require reactor pumps is that that's how one gets the > energy out of the reaction! The point is that it may be possible to turn a fusion plant completely off. That is not possible with a fission plant, since approximately one-third of the heat generation comes from decay of fission products rather than from the chain reaction in progress. (Obviously the exact values depend on the reactor design and on how long it has already been running.) In the Three Mile Island accident, for example, the chain reaction was stopped almost immediately, but the decay heat of the fission products still melted much of the core.