Scoping Study Investigating PWR Instrumentation during a Severe Accident Scenario

Abstract

The accidents at the Three Mile Island Unit 2 (TMI-2) and Fukushima Daiichi Units 1, 2, and 3 nuclear power plants demonstrate the critical importance of accurate, relevant, and timely information on the status of reactor systems during a severe accident. These events also highlight the critical importance of understanding and focusing on the key elements of system status information in an environment where operators may be overwhelmed with superfluous and sometimes conflicting data. While progress in these areas has been made since TMI-2, the events at Fukushima suggest there may still be a potential need to ensure critical plant information is available to plant operators. Recognizing the significant technical and economic challenges associated with plant modifications, it is important to focus on instrumentation that can efficiently address these critical information needs. INL/EXT-15-35940 iv v INL/EXT-15-35940 INL/EXT-15-35940 vi

Light Water Reactor Sustainability Program, U.S. Efforts in Support of Examinations at Fukushima Daiichi-2017 Evaluations

“…The need for reliable instrumentation was recognized after the TMI-2 event, [6] and the events at Fukushima have again emphasized the importance of operators having access to critical information from plant instrumentation. To address potential measures under consideration by the U.S. NRC [57 through 60], several efforts have been sponsored by the U.S. DOE [61,62] and industry groups. [63 through 66]…”

“…Figure61. MELTSPREAD predictions of liner heatup due to heat transfer from impinging melt for 1F1 based on a MAAP low pressure (LP) scenario[50] (left) and MELCOR[49] (right) melt pour conditions.…”