Simplified analysis technique for estimating the value of safety-system improvements. [PWR; BWR]

It has been shown that by using a simplified probabilistic risk assessment (PRA) analysis technique, important insights can be gained regarding potential value of safety system improvements. However, because the technique also eliminates much of the detail normally associated with PRAs, insights gained from the technique should not be treated as conclusive but rather as indications of areas requiring further investigation. The technique has been applied at Sandia to both pressurized and boiling water reactors to assess the value of alternative decay heat removal systems and to compare the relative benefits of alternative accident prevention and mitigation systems.