Discussion: Session 3b

R. W. DURHAM Atomic Energy Canada Limited

What are the consequences of not knowing (a) 239-Pu accurately, and how does this effect breeding gain and reactor design.

E.A.C. CROUCH

I must point out that this question has really been answered fully by H. Cartwright, et al

(Ref. Dl). However as this reference alone would not give much feeling for particular numbers, I can quote a paper by R.D. Smith (Ref. D2) in which he pointed out that in a particular case an uncertainty of the breeding gain of ± 0.1 would lead to an estimate of the doubling time of between 10 and 20 years, and an uncertainty of the price of the generated electricity of about ± 10%. Because a core has to be optimized on a particular value of the breeding gain this datura should be known to ± 0.05(i.e. about ± 3.5% in a),