NESC1063 SEISIM1.
SEISIM-1, Seismic Probabilistic Risk Assessment
NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROGRAM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES
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| Program name | Package id | Status | Status date |
|---|---|---|---|
| SEISIM-1 | NESC1063/01 | Tested | 27-APR-1988 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| NESC1063/01 | CDC 7600 | CDC CYBER 830 |
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3. DESCRIPTION OF PROGRAM OR FUNCTION
SEISIM1 calculates the probabilities of seismically induced failures for components and systems and propagates these calculations to determine the probability of accident sequences and the resulting total risk, which is quantified as an expected value of radiation release and exposure from a given nuclear power plant. SEISIM1 was developed as a fundamental tool for the systems analysis portion of the NRC's Seismic Safety Margins Research Program (SSMRP). The SSMRP provides a complete, self-contained methodology to assess and quantify the risk to nuclear power plants from seismic events and seismically induced failures.
SEISIM1 calculates the probabilities of seismically induced failures for components and systems and propagates these calculations to determine the probability of accident sequences and the resulting total risk, which is quantified as an expected value of radiation release and exposure from a given nuclear power plant. SEISIM1 was developed as a fundamental tool for the systems analysis portion of the NRC's Seismic Safety Margins Research Program (SSMRP). The SSMRP provides a complete, self-contained methodology to assess and quantify the risk to nuclear power plants from seismic events and seismically induced failures.
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4. METHOD OF SOLUTION
Accident sequence and system failure probabilities are computed from cut-set probabilities, utilizing three alternative approximation schemes, which represent the probabilities as unions of cut sets. All cut-set probabilities containing response-dependent basic events are converted to multinormal integrals, which are calculated using numerical integration. SEISMI1 computes each release sequence probability by multiplying the initiating event and accident sequence probabilities by the probabilities of earthquake and containment failure. Release category probabilities are computed by adding the probabilities of all release sequences associated with that release category.
Accident sequence and system failure probabilities are computed from cut-set probabilities, utilizing three alternative approximation schemes, which represent the probabilities as unions of cut sets. All cut-set probabilities containing response-dependent basic events are converted to multinormal integrals, which are calculated using numerical integration. SEISMI1 computes each release sequence probability by multiplying the initiating event and accident sequence probabilities by the probabilities of earthquake and containment failure. Release category probabilities are computed by adding the probabilities of all release sequences associated with that release category.
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6. TYPICAL RUNNING TIME
NESC executed the sample problem, which consists of two initiating events, 12 accident sequences, three logical component groups, and 91 basic events, in 4 CP seconds on a CDC7600.
NESC executed the sample problem, which consists of two initiating events, 12 accident sequences, three logical component groups, and 91 basic events, in 4 CP seconds on a CDC7600.
NESC1063/01
NEA-DB executed the test case included in this package on a CDC CYBER 830 computer in 36 seconds of CPU time.[ top ]
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10. REFERENCES
- SEISIM1, NESC No. 1063, SEISIM1 Tape Description and
Implementation Information,
National Energy Software Center Note 86-76, July 14, 1986.
- J.E. Wells, L.L. George, and G.E. Cummings,
Seismic Safety Margins Research Program Phase I Final Report -
Systems Analysis (Project VII),
NUREG/CR-2015 (UCRL-53021), Vol. 8, November 1981.
- P.D. Smith, D.L. Bernreuter, M.P. Bohn, T.Y. Chuang, G.E.
Cummings, R.D. Dong, J.J. Johnson, R.W. Mensing, and J.E. Wells,
An Overview of Seismic Risk Analysis for Nuclear Power Plants,
UCID-18680, September 11, 1980.
- SEISIM1, NESC No. 1063, SEISIM1 Tape Description and
Implementation Information,
National Energy Software Center Note 86-76, July 14, 1986.
- J.E. Wells, L.L. George, and G.E. Cummings,
Seismic Safety Margins Research Program Phase I Final Report -
Systems Analysis (Project VII),
NUREG/CR-2015 (UCRL-53021), Vol. 8, November 1981.
- P.D. Smith, D.L. Bernreuter, M.P. Bohn, T.Y. Chuang, G.E.
Cummings, R.D. Dong, J.J. Johnson, R.W. Mensing, and J.E. Wells,
An Overview of Seismic Risk Analysis for Nuclear Power Plants,
UCID-18680, September 11, 1980.
NESC1063/01, included references:
- Laurence L. George et al.:SEISIM - Systematic Evaluation of Important Safety Improvement
Measures: User Manual.
UCID-20496 (July 1985)
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11. MACHINE REQUIREMENTS
121,000 (octal) words of SCM and 553,000 (octal) words of LCM are required for execution.
121,000 (octal) words of SCM and 553,000 (octal) words of LCM are required for execution.
NESC1063/01
Main storage requirements for executing the test case on a CDC CYBER 830 are : 161,562 (octal) words (CM); 552,460 (octal) words (LCM).[ top ]
NESC1063/01
NOS2.5.1 (CDC CYBER 830).[ top ]
14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS
SEISIM1 requires as input, files created by other programs developed as part of the SSMRP project. In particular, the SMACS program (NESC 9706) provides the response data for SEISIM1. SEISIM1 calls subroutines MDNOR and MDNRIS from proprietary International Mathematical and Statistical Library, Inc. (IMSL); these routines are not included.
SEISIM1 requires as input, files created by other programs developed as part of the SSMRP project. In particular, the SMACS program (NESC 9706) provides the response data for SEISIM1. SEISIM1 calls subroutines MDNOR and MDNRIS from proprietary International Mathematical and Statistical Library, Inc. (IMSL); these routines are not included.
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NESC1063/01
| File name | File description | Records |
|---|---|---|
| NESC1063_01.001 | Information file | 66 |
| NESC1063_01.002 | JCL and control information | 28 |
| NESC1063_01.003 | SEISIM source program | 3884 |
| NESC1063_01.004 | Sample problem input INFILE | 20 |
| NESC1063_01.005 | Sample problem input LUFILE | 25 |
| NESC1063_01.006 | Sample problem input REFILE | 260 |
| NESC1063_01.007 | Sample problem input CRFILE | 71 |
| NESC1063_01.008 | Sample problem input FRFILE | 31 |
| NESC1063_01.009 | Sample problem input LCFILE | 63 |
| NESC1063_01.010 | Sample problem input IEFILE | 18 |
| NESC1063_01.011 | Sample problem input ASFILE | 144 |
| NESC1063_01.012 | IMSL SUBROUTINES | 9 |
| NESC1063_01.013 | Sample problem output | 1517 |
| NESC1063_01.014 | Sample problem output OUTP | 269 |
Keywords: nuclear power plants, risk assessment, safety, seismic effects, systems analysis.