Session A: Discussion

PAPER 1

Mr P.H. Margen, AB Atomenergi, Stockholm

Past UK policy seems to have been to consider the AGR as the unit for large out puts and the SGHWR as that for small out puts. However, the marginal cost (i.e., cost increase resulting from increase in output/increase in output) with increasing unit size is dominated by the fuel cycle cost component: reactors with low fuel cycle costs tend to attain their strongest competitive position at large outputs. HWRs (particularly variants with D2O coolant, but to some- extent even SGHWRs) have lower fuel cycle costs than AGRs or LWRs. Hence they should be preferred for large outputs. I notice that more mention has been made at this conference of SGHWRs for large outputs than has been the case in the past. Does this indicate a change in UK policy?