NEED FOR CONSENSUS ON THE DETERMINATION OF THE MARGIN OF SUBCRITICALITY

摘要

The practices for determination of maximum acceptable effective multiplication factor (K_(eff)) across the criticality community have evolved almost autonomously in two sections namely, government and the nuclear industry for a variety of reasons. These reasons include varying requirements for independent auditability and a difference in regulatory bodies overseeing nuclear safety in the government and nuclear industry arenas. As is commonly known, the government sector put larger emphasis on the programmatic aspects than the nuclear utility industry was allowed in assuring nuclear safety till the late eighties. While the earlier development of nuclear power industiy in sixties, of necessity, evolved out of the government experience in the control of criticality, there is general agreement that by the end of the eighties the DOE was convinced that multi-party interactions between nuclear utilities and the USNRC had led to a greater emphasis on documentability of criticality safety. Furthermore, at that time the importance of independent auditability of safety practices was established as a goal for DOE institutions.