ML23045A289

RIC 2023 - 03/14/2023 to 03/16/2023 Regulatory Information Conference (Ric).Operational and Safety Benefits of Risk Informed Applications

ML23045A289
Person / Time
Site:	Nuclear Energy Institute
Issue date:	03/14/2023
From:	Nuclear Energy Institute
To:	Office of Nuclear Reactor Regulation
References
Download: ML23045A289 (1)

Text

Operational and Safety Benefits of Risk Informed Applications NRC Regulatory Information Conference March 14, 2023

©2023 Nuclear Energy Institute

General Themes in Risk Informed Application Benefits Reduction in outage complexity, duration, and risk Flexibility to better focus maintenance and repairs Averted shutdowns Completion of deferred maintenance without additional license amendments or exemptions Reduced personnel dose Refocusing of staff hours on more impactful issues

©2023 Nuclear Energy Institute 2

TSTF-425, Risk Informed Surveillance Frequency Control Program

• Allows licensees to move tech spec surveillance frequencies to a licensee-controlled program and to use risk information to extend these

• Major benefits:

• Streamlining of testing programs to reduce burden on plant personnel

• Potential to shorten outages with less frequent testing

• Reduction of frequency for tests that stress plant systems

©2023 Nuclear Energy Institute 3

Plant Specific Benefits: TSTF-425 Success Station blackout test extension

• Allows performance of test on one division instead of two

• Significantly reduces outage complexity

• Reduces dose

• Lessens the potential for test-caused errors

• Reduces outage length up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> EDG Operability Test Extension

• Supports train-specific outages

• Substantially reduces outage risk and complexity

©2023 Nuclear Energy Institute 4

50.69, Risk Informed Special Treatments

• Allows licensees to recategorize some safety-related equipment with low risk significance to streamline various operational programs (e.g.

maintenance, procurement)

• Major benefits:

• Potential for substantial reduction in Appendix B (Quality Assurance) scope

• Improves program focus on most risk-significant components

©2023 Nuclear Energy Institute 5

Plant Specific Benefits: 50.69 Success Aggregate benefits at two-unit PWR, several years into implementation

• Permanent 1 person-rem/year reduction

• Maintenance Rule scope reduction allows for reallocation of 230 engineering hours per year

• Procurement lead time for safety-related parts cut in half Specific successes

• Relief valve downgraded to removed from IST test Allowed test to be conducted despite inability to isolate valve

• Simplification of process to address known pin hole leak issues Supported streamlined piping replacement

©2023 Nuclear Energy Institute 6

TSTF-505, Risk Informed Tech Spec Completion Times

• Allows licensees to extend equipment allowed outage time to up to 30 days based on a plant-configuration specific risk assessment

• Major benefits:

• Avoidance of unplanned shutdowns (economic and safety improvement)

• More deliberate maintenance practices

• Substantial reduction in need for NOEDs

©2023 Nuclear Energy Institute 7

Plant-Specific Benefits: TSTF-505 Success Averted shutdowns

• 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> tech spec limitation extended to 71-hour Risk Informed Completion Time Enabled repair to be delayed until more timely preparations could be implemented Supported improved grid stability during a time of high demand with averted shutdown Additional online work enabled, reducing outage risk

• Conducting piping replacement online 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br /> of outage length reduction

• Moving cable work online 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> of outage length reduction

©2023 Nuclear Energy Institute 8

Summary of Risk Informed Application Benefits Refocusing of utility and NRC resources on issues most relevant to plant operation, performance, and safety Streamlining of plant operations to support improved performance and more timely resolution of operational issues Overall reduction in challenges to plant

©2023 Nuclear Energy Institute 9