Is Mark I shell failure really important? Pt. 2

This second part of a two part paper provides specific analyses performed on the reactor safety study's reference BWR, the Peach Bottom Plant. Source terms are provided for a series of station blackout accident sequences. In the base case, failure of the drywell is calculated to occur shortly after reactor vessel failure. The source terms associated with this sequence are in the few percent range for iodine, cesium, and tellurium. Because the containment failure occurs upon reactor vessel failure, this source term is expected to be equal to or larger than the source term that would be associated with shell failure. A sensitivity analysis was also performed to evaluate the benefits of extended use of the automatic depressurization system in station blackout sequences. Among the benefits of extended ADS operation are reduced source terms and a decreased probability of prompt containment failure when the reactor vessel fails. (orig.)