Performing a multi-unit level-3 PSA with MACCS

Bixler, Nathan E.; Kim, Sung-yeop

doi:10.1016/j.net.2020.07.034

Performing a multi-unit level-3 PSA with MACCS

Journal Article · Tue Jul 28 00:00:00 EDT 2020 · Nuclear Engineering and Technology

DOI:https://doi.org/10.1016/j.net.2020.07.034· OSTI ID:1670185

Bixler, Nathan E. ^[1]; Kim, Sung-yeop ^[2]

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Korea Atomic Energy Reseach Inst., Daejeon (Korea, Republic of)

MACCS (MELCOR Accident Consequence Code System), WinMACCS, and MelMACCS now facilitate a multi-unit consequence analysis. MACCS evaluates the consequences of an atmospheric release of radioactive gases and aerosols into the atmosphere and is most commonly used to perform probabilistic safety assessments (PSAs) and related consequence analyses for nuclear power plants (NPPs). WinMACCS is a user-friendly preprocessor for MACCS. MelMACCS extracts source-term information from a MELCOR plot file. The current development can combine an arbitrary number of source terms, representing simultaneous releases from a multi-unit facility, into a single consequence analysis. The development supports different release signatures, fission product inventories, and accident initiation times for each unit. The treatment is completely general except that the model is currently limited to collocated units. A major practical consideration for performing a multi-unit PSA is that a comprehensive treatment for more than two units may involve an intractable number of combinations of source terms. This paper proposes and evaluates an approach for reducing the number of calculations to be tractable, even for sites with eight or ten units. The approximation error introduced by the approach is acceptable and is considerably less than other errors and uncertainties inherent in a Level 3 PSA.

Research Organization:: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC04-94AL85000

OSTI ID:: 1670185

Alternate ID(s):: OSTI ID: 1643651
OSTI ID: 23072956

Report Number(s):: SAND--2020-6464J; 686893

Journal Information:: Nuclear Engineering and Technology, Journal Name: Nuclear Engineering and Technology Journal Issue: 2 Vol. 53; ISSN 1738-5733

Publisher:: Korean Nuclear SocietyCopyright Statement

Country of Publication:: United States

Language:: English

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