Qualification of Daiichi Units 1, 2, and 3 Data for Severe Accident Evaluations - Process and Illustrative Examples from Prior TMI-2 Evaluations

Rempe, Joy Lynn¹  Knudson, Darrell Lee¹ 

[1]Idaho National Lab. (INL), Idaho Falls, ID (United States)

关键词: COMPARATIVE EVALUATIONS;    CONTAINMENT BUILDINGS;    THREE MILE ISLAND-2 REACTOR;    SENSORS;    REVIEWS;    HYDROGEN;    HUMIDITY;    CONTAMINATION;    LOSS OF COOLANT;    SIMULATION;    REACTOR INSTRUMENTATION;    MELTDOWN;    RADIATION EFFECTS;    FUKUSHIMA ACCIDENT DATA;    FUKUSHIMA-1 REACTOR;    FUKUSHIMA-2 REACTOR;    FUKUSHIMA-3 REACTOR Instrumentation;    Three Mile Island Unit 2;   

DOI  :  10.2172/1235193
RP-ID  :  INL/EXT--14-32628
PID  :  OSTI ID: 1235193
Others  :  TRN: US1600229

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来源: SciTech Connect

【 摘 要 】

The accidents at the Three Mile Island Unit 2 (TMI-2) Pressurized Water Reactor (PWR) and the Daiichi Units 1, 2, and 3 Boiling Water Reactors (BWRs) provide unique opportunities to evaluate instrumentation exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during the TMI-2 accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This initial review focused on the set of sensors deemed most important by post-TMI-2 instrumentation evaluation programs. Instrumentation evaluation programs focused on data required by TMI-2 operators to assess the condition of the reactor and containment and the effect of mitigating actions taken by these operators. In addition, prior efforts focused on sensors providing data required for subsequent forensic evaluations and accident simulations. To encourage the potential for similar activities to be completed for qualifying data from Daiichi Units 1, 2, and 3, this report provides additional details related to the formal process used to develop a qualified TMI-2 data base and presents data qualification details for three parameters: primary system pressure; containment building temperature; and containment pressure. As described within this report, sensor evaluations and data qualification required implementation of various processes, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design to instruments easily removed from the TMI-2 plant for evaluations. As documented in this report, results from qualifying data for these parameters led to key insights related to TMI-2 accident progression. Hence, these selected examples illustrate the types of activities completed in the TMI-2 data qualification process and the importance of such a qualification effort. These details are documented in this report to facilitate implementation of similar process using data and examinations at the Daiichi Units 1, 2, and 3 reactors so that BWR-specific benefits can be obtained.