Report to the American Physical Society by the study group on light-water reactor safety

Abstract

The issue of light-water reactor (LWR) safety has been the subject of a part-time, year-long study sponsored by the American Physical Society. The goal of the study was the assessment of some of the technical aspects of the safety of large light-water nuclear power reactors typical of present commercial practice in the Unted States. The report examines issues related to safe operation of LWRs; the research and development program responsible for establishing and enhancing safety; and the consequences of accidents for public health and welfare. The report in no way deals with the need for nuclear power or its benefits, and should not be considered as a net assessment of the risks versus the benefits of nuclear reactors. Since the risks of ecological impacts of other energy technologies are not addressed, no recommendations are made concerning the specific reactor program which should be followed in the immediate future. Among the areas covered in the report are primary pressure-vessel integrity; quality assurance; accident initiation from operator error, transients, and sabotage; the adequacy of present emergency core-cooling system designs; the calculation of long-term consequences to health of one particular low-probability accidental release of radioactivity; and the experimental and calculational (computer-code-development) aspects of the present reactor safety ' We were fortunate that early in our study we were given copies in preliminary draft of the AEC-sponsored study of reactor safety (chaired by Professor Norman Rasmussen of M.E.T. , and known as WASH -1400). WASH-1400 is a detailed event-tree and fault-tree analysis of light-water reactor accident sequences. Its purpose was to make a quantitative estimate of the likelihood of accident consequences of a given severity. We did not undertake a review of that study as such, although it will be mentioned frequently in our report.The gracious hospitality of the Los Alamos Scientific Laboratory and the administrative assistance of the staff of the American Physical Society are also acknowledged. This study was supported by the National Science Foundation and the U. S. Atomic Energy Commission.The study participants have all agreed on both the broad conclusions and the more detailed individual recommendations contained in the body of the report. We believe this is significant in view of the diverse backgrounds of the group. Our individual technical expertise ranges widely, covering theoretical and experimental physics, chemistry, and engineering. While a few of the group had some background in reactor safety, the majority of the group had not previously considered these issues. Some of the group had participated in previous technical assessments of broad national issues; for sevSince this work was begun the Atomic Energy Commission has been split in two parts: the Energy Research and Development Administration (ERDA) and the Nuclear Regulatory Commission (NRC), and the exact distribution between ERDA and NRC of the responsibility that formerly resided...

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