Cost-benefit considerations for filtered-vented containment systems

As part of Sandia's severe accident research program for the U.S. Nuclear Regulatory Commission, we have been investigating the cost-benefit tradeoffs of filtered-vented containment (FVC) systems for a variety of reactory types. To quantify these evaluations, we have been assessing the reduction in accident risks that is achievable from a variety of containment venting concepts and the costs associated with retrofitting these concepts into existing reactors. We have been appraising our results in terms of the Commission's proposed safety goals and in terms of the true costs of reactor accidents. Our preliminary results indicate that FVC systems are not cost effective for most of the pressurized water reactors that we have evaluated. On the other hand, they appear to be potentially cost effective for the boiling water reactors. The promising results for BWRs, however, are predicted on a simple, inexpensive containment venting design that uses only the existing suppression pool as a scrubber. 2 figures, 6 tables.