Value-impact analysis of severe-accident prevention and mitigation systems. [PWR; BWR]

As part of Sandia's Severe Accident Risk Reduction (SARR) Program for the U.S. Nuclear Regulatory Commission, the cost-benefit tradeoffs of filtered-vented containment (FVC) systems, hydrogen control systems, alternate decay heat removal systems, and a variety of other reactor modifications designed to reduce the risk from severe accidents have been studied. Some of the preliminary results to data indicate that (1) FVC systems are potentially cost-effective for many BWRs, but apparently not cost-effective for most PWRs; (2) the opposite is true for hydrogen control systems; and (3) the most effective safety approaches include combinations of both preventive and mitigative features. Further analyses are being performed to fully investigate the sensitivity of these results to uncertainties.