An overview of reactor physics standards: Past, present and future

This report discusses for determining key static reactor physics parameters which have been developed by groups of experts (working groups) under the aegis of ANS-19, the ANS Reactor Physics Standards Committee. Following a series of sequential reviews, augmented by feedback from potential users, a proposed standard is brought into final form by the working group before it is adopted as a formal standard by the American National Standards Institute (ANSI); Reactor Physics standards are intended to provide guidance in the performance and qualification of complex sequences of reactor calculations and/or measurements and are regularly reviewed for possible updates and/or revisions. The reactor physics standards developed to date are listed and standards now being developed by the respective working groups are also provided

Dynamic behavior of a subcooled BWR core during a rod-drop accident

The techniques and models used in the study of rapid reactivity insertion in a BWR have ranged from approximate conservative methods with simple feedback models to detailed representations of coupled neutronic thermal-hydraulic mechanisms. In a recent paper Cheng and Diamond presented a detailed evaluation of the control rod drop accident (CRDA). Their calculations suggested that the effect of inlet subcooling and rod drop speed may play an important role in determining the severity of the rod drop accident. The purpose of the work summarized in this paper has been to determine in detail the dynamic behavior of a BWR core as the inlet moderator temperature and the speed of the dropped rod are varied