Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability
The Nuclear Regulatory Commission's (NRC) steady progress towards risk-informed performance-based regulation (RIPBR) prompted the practical application of this regulatory tool in order to demonstrate its potential benefits. This practical demonstration makes up one part of an Idaho National...
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| Beste egile batzuk: | |
| Formatua: | Technical Report |
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Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program
2011
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| Sarrera elektronikoa: | http://hdl.handle.net/1721.1/67649 |
| _version_ | 1826197523606274048 |
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| author | Utton, S. Golay, M. W. |
| author2 | Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) |
| author_facet | Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) Utton, S. Golay, M. W. |
| author_sort | Utton, S. |
| collection | MIT |
| description | The Nuclear Regulatory Commission's (NRC) steady progress towards risk-informed
performance-based regulation (RIPBR) prompted the practical application of this
regulatory tool in order to demonstrate its potential benefits. This practical demonstration
makes up one part of an Idaho National Engineering and Environmental Laboratory
(INEEL) sponsored project entitled Integrated Models, Data Bases and Practices Needed
for Performance-Based Safety Regulation. Project members selected the emergency
diesel generator system as a candidate for assessment because of its high risk importance
for core damage frequency (CDF) as well as for its failure to exhibit fulfillment of its
current maintenance objectives.
An analysis of current NRC maintenance and inspection requirements of the
emergency diesel generators at the Millstone 3 nuclear power plant was performed by the
project members. Maintenance and inspection items identified as unnecessary or harmful
to the EDG qualified as candidates for removal from the current surveillance schedule.
Expert testimony and comparisons with similar non-nuclear utility industries aided in the
identification of candidate items.
Calculations of the subsequent risk, reliability, safety, and economic implications
revealed several benefits of the inspection alterations. The modified inspection provided
improved backup power availability and defense in depth during the refueling outage. A
sensitivity analysis performed on the EDG basic events affected by inspection alteration
showed that a 50% reduction in these basic event failure rates would decrease the EDG
system failure probability by 13.9%. The altered inspection also shortens the plant's
refueling outage critical path therefore decreasing the risk of fuel damage and improving
the risk profile of the plant outage. Transfer of the revised inspection to performance
while the plant is operating at power resulted in identical refueling outage benefits.
Performance of the inspection at power requires an increase in the allowed outage time
(AOT) of the plant. The subsequent rise in core damage frequency due to the increased
AOT is considered negligible. |
| first_indexed | 2024-09-23T10:49:19Z |
| format | Technical Report |
| id | mit-1721.1/67649 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T10:49:19Z |
| publishDate | 2011 |
| publisher | Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program |
| record_format | dspace |
| spelling | mit-1721.1/676492019-04-12T15:04:26Z Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability Utton, S. Golay, M. W. Advanced Nuclear Power Technology Program (Massachusetts Institute of Technology) Utton, S. Golay, M. W. The Nuclear Regulatory Commission's (NRC) steady progress towards risk-informed performance-based regulation (RIPBR) prompted the practical application of this regulatory tool in order to demonstrate its potential benefits. This practical demonstration makes up one part of an Idaho National Engineering and Environmental Laboratory (INEEL) sponsored project entitled Integrated Models, Data Bases and Practices Needed for Performance-Based Safety Regulation. Project members selected the emergency diesel generator system as a candidate for assessment because of its high risk importance for core damage frequency (CDF) as well as for its failure to exhibit fulfillment of its current maintenance objectives. An analysis of current NRC maintenance and inspection requirements of the emergency diesel generators at the Millstone 3 nuclear power plant was performed by the project members. Maintenance and inspection items identified as unnecessary or harmful to the EDG qualified as candidates for removal from the current surveillance schedule. Expert testimony and comparisons with similar non-nuclear utility industries aided in the identification of candidate items. Calculations of the subsequent risk, reliability, safety, and economic implications revealed several benefits of the inspection alterations. The modified inspection provided improved backup power availability and defense in depth during the refueling outage. A sensitivity analysis performed on the EDG basic events affected by inspection alteration showed that a 50% reduction in these basic event failure rates would decrease the EDG system failure probability by 13.9%. The altered inspection also shortens the plant's refueling outage critical path therefore decreasing the risk of fuel damage and improving the risk profile of the plant outage. Transfer of the revised inspection to performance while the plant is operating at power resulted in identical refueling outage benefits. Performance of the inspection at power requires an increase in the allowed outage time (AOT) of the plant. The subsequent rise in core damage frequency due to the increased AOT is considered negligible. INEEL University Research Consortium United States. Dept. of Energy (Contract No. DE-AC07-941D13223) 2011-12-13T20:55:41Z 2011-12-13T20:55:41Z 1998-01 Technical Report http://hdl.handle.net/1721.1/67649 MIT-ANP;TR-058 application/pdf Massachusetts Institute of Technology. Center for Advanced Nuclear Energy Systems. Advanced Nuclear Power Program |
| spellingShingle | Utton, S. Golay, M. W. Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title | Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title_full | Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title_fullStr | Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title_full_unstemmed | Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title_short | Risk-Informed, Performance-Based Regulatory Implications of Improved Emergency Diesel Generator Reliability |
| title_sort | risk informed performance based regulatory implications of improved emergency diesel generator reliability |
| url | http://hdl.handle.net/1721.1/67649 |
| work_keys_str_mv | AT uttons riskinformedperformancebasedregulatoryimplicationsofimprovedemergencydieselgeneratorreliability AT golaymw riskinformedperformancebasedregulatoryimplicationsofimprovedemergencydieselgeneratorreliability |