skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Review of light water reactor regulatory requirements: Assessment of selected regulatory requirements that may have marginal importance to risk: Postaccident sampling system, Turbine missiles, Combustible gas control, Charcoal filters

Technical Report ·
OSTI ID:6519761

In a study commissioned by the Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory (PNL) evaluated the costs and benefits of modifying regulatory requirements in the areas of the postaccident sampling system, turbine rotor design reviews and inspections, combustible gas control for inerted Boiling Water Reactor (BWR) containments, and impregnated charcoal filters in certain plant ventilation systems. The basic framework for the analyses was that presented in the Regulatory Analysis Guidelines (NUREG/BR-0058) and in the Handbook for Value-Impact Assessment (NUREG/CR-3568). The effects of selected modifications to regulations were evaluated in terms of such factors as public risk and costs to industry and NRC. The results indicate that potential modifications of the regulatory requirements in three of the four areas would have little impact on public risk. In the fourth area, impregnated charcoal filters in building ventilation systems do appear to limit risks to the public and plant staff. Revisions in the severe accident source term assumptions, however, may reduce the theoretical value of charcoal filters. The cost analysis indicated that substantial savings in operating costs may be realized by changing the interval of turbine rotor inspections. Small to moderate operating cost savings may be realized through postulated modifications to the postaccident sampling system requirements and to the requirements for combustible gas control in inerted BWR containments. Finally, the use of impregnated charcoal filters in ventilation systems appears to be the most cost-effective method of reducing radioiodine concentrations.

Research Organization:
Pacific Northwest Lab., Richland, WA (USA); Nuclear Regulatory Commission, Washington, DC (USA). Div. of Regulatory Applications
DOE Contract Number:
AC06-76RL01830
OSTI ID:
6519761
Report Number(s):
NUREG/CR-4330-Vol.3; PNL-5809-Vol.3; ON: TI87009815
Country of Publication:
United States
Language:
English