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Title: The probability of containment failure by direct containment heating in Zion. Supplement 1

Technical Report ·
DOI:https://doi.org/10.2172/10106612· OSTI ID:10106612
; ; ;  [1];  [2]
  1. Sandia National Labs., Albuquerque, NM (United States)
  2. Idaho National Engineering Lab., Idaho Falls, ID (United States)

Supplement 1 of NUREG/CR-6075 brings to closure the DCH issue for the Zion plant. It includes the documentation of the peer review process for NUREG/CR-6075, the assessments of four new splinter scenarios defined in working group meetings, and modeling enhancements recommended by the working groups. In the four new scenarios, consistency of the initial conditions has been implemented by using insights from systems-level codes. SCDAP/RELAP5 was used to analyze three short-term station blackout cases with Different lead rates. In all three case, the hot leg or surge line failed well before the lower head and thus the primary system depressurized to a point where DCH was no longer considered a threat. However, these calculations were continued to lower head failure in order to gain insights that were useful in establishing the initial and boundary conditions. The most useful insights are that the RCS pressure is-low at vessel breach metallic blockages in the core region do not melt and relocate into the lower plenum, and melting of upper plenum steel is correlated with hot leg failure. THE SCDAP/RELAP output was used as input to CONTAIN to assess the containment conditions at vessel breach. The containment-side conditions predicted by CONTAIN are similar to those originally specified in NUREG/CR-6075.

Research Organization:
Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Research; Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
Nuclear Regulatory Commission, Washington, DC (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
10106612
Report Number(s):
NUREG/CR-6075-Suppl.1; SAND-93-1535-Suppl.1; ON: TI95005274; BR: GB0103012
Resource Relation:
Other Information: PBD: Dec 1994
Country of Publication:
United States
Language:
English