APPLICATION OF REVEAL-W(TM) TO RISK-BASED CONFIGURATION CONTROL

Over the past two years, the concept of risk-based configuration control has been introduced to the US Nuclear Regulatory Commission and the nuclear industry. Converting much of the current, deterministically based regulation of nuclear power plants to risk-based regulation can result in lower levels of risk while relieving unnecessary burdens on power plant operators and regulatory staff. To achieve the potential benefits of risk-based configuration control, the risk models developed for nuclear power plants should be (1) flexible enough to effectively support necessary risk calculations, and (2) transparent enough to encourage their use by all parties. To address these needs, SCIENTECH, Inc., has developed the PC-based REVEAL-W(TM) (formerly known as SMART). This graphic-oriented and user-friendly application software allows the user to develop transparent complex logic models based on the concept of the master plant logic diagram. The logic model is success-oriented and compact. It is also highly modularized and displays systems' interactions in a hierarchical fashion. This modularity, combined with the graphic Windows(TM) environment, allows the user to change easily a portion of the plant logic, based on a change in configuration, and immediately observe the effect of the change on the entire plant logic. This capability makes REVEAL-W(TM) a suitable advisory tool for a plant's maintenance and operating staffs, who can use it to analyze the impact of their planned or unplanned maintenance or surveillance tests on the plant's risk profile. The analytical capability built into REVEAL-W(TM) is generic, so the software can support different types of risk-based evaluations, such as probabilistic safety assessment, accident sequence precursor analysis, design evaluation and configuration management. In this paper, we focus on the application of REVEAL-W(TM) to support risk-based configuration control of nuclear power plants.