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Title: External Cooling of the BWR Mark I and II Drywell Head as a Potential Accident Mitigation Measure – Expanded Scoping Assessment

Technical Report ·
DOI:https://doi.org/10.2172/1470864· OSTI ID:1470864
 [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

This report documents a scoping assessment of a potential accident mitigation action applicable to the US fleet of boiling water reactors with Mark I and II containments. The mitigation action is to externally flood the primary containment vessel drywell head using portable pumps or other means. A scoping assessment of the potential benefits of this mitigation action was conducted focusing on the ability to (1) passively remove heat from containment, (2) prevent or delay leakage through the drywell head seal (due to high temperatures and/or pressure), and (3) scrub radionuclide releases if the drywell head seal leaks. This report is an expanded revision of ORNL/TM-2017/457 and includes an analysis of (1) the delay in initiating drywell head cavity flooding from 2 hours to 8 hours after accident scenario initiation and (2) the effectiveness of including additional drywell head heat transfer area.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-00OR22725
OSTI ID:
1470864
Report Number(s):
ORNL/TM-2018/901; TRN: US1902851
Country of Publication:
United States
Language:
English