ML070110192

Regulatory Conference Clinton High Pressure Core Spray Finding NRC Presentation

ML070110192
Person / Time
Site:	Clinton
Issue date:	12/19/2006
From:	Pederson C Division of Reactor Safety III
To:
References
EA-06-291
Download: ML070110192 (7)

Text

Regulatory Conference Regulatory Conference Clinton High Pressure Core Spray Finding Clinton High Pressure Core Spray Finding Nuclear Regulatory Commission Nuclear Regulatory Commission -- Region III Region III Lisle, Illinois Lisle, Illinois December 19, 2006 December 19, 2006

Introduction and Opening Remarks Introduction and Opening Remarks Cynthia Pederson Cynthia Pederson Director Director Division of Reactor Safety Division of Reactor Safety

Agenda Agenda Introduction and Opening Remarks Introduction and Opening Remarks Overview of Inspection Finding Overview of Inspection Finding

• • Description of Vortex Issue Description of Vortex Issue

• • Description of Performance Deficiency Description of Performance Deficiency

• • Preliminary Safety Significance Determination Preliminary Safety Significance Determination and Apparent Violation and Apparent Violation Licensee Presentation Licensee Presentation NRC Caucus NRC Caucus Closing Remarks Closing Remarks Public Comments Public Comments

Description of Vortex Issue Description of Vortex Issue Calculation IP Calculation IP--M M--0384, Revisions 0 and 1:

0384, Revisions 0 and 1:

• • Air entrained into the suction of High Pressure Core Spray Air entrained into the suction of High Pressure Core Spray (HPCS)

(HPCS)

• • Assumed linear relationship (air entrained over time) without Assumed linear relationship (air entrained over time) without sufficient justification sufficient justification Calculation IP Calculation IP--M M--0384, Revision 1B 0384, Revision 1B

• • Used correlation that was not appropriate for assumed flow Used correlation that was not appropriate for assumed flow conditions conditions

• • Assumed linear relationship (air entrained over time) without Assumed linear relationship (air entrained over time) without sufficient justification sufficient justification Past operability not supported, potential for significant Past operability not supported, potential for significant amount of air which would prevent completion of safety amount of air which would prevent completion of safety function function

Performance Deficiency Performance Deficiency Failure to meet requirement Failure to meet requirement

• • 10 CFR 50, Appendix B, Criterion III, Design 10 CFR 50, Appendix B, Criterion III, Design Control Control

• • Failure to select an appropriate method for Failure to select an appropriate method for calculating the onset of a vortex at the intake calculating the onset of a vortex at the intake of the HPCS pumps suction line from the RCIC of the HPCS pumps suction line from the RCIC tank and subsequently demonstrate the HPCS tank and subsequently demonstrate the HPCS system would be capable of performing its system would be capable of performing its safety function.

safety function.

Cause within licensees ability to foresee Cause within licensees ability to foresee and correct and correct

• • Vortex issue was previously identified by the Vortex issue was previously identified by the licensee in 1998.

licensee in 1998.

Safety Significance Determination Safety Significance Determination (Preliminary)

(Preliminary)

Phase III Analysis Assumptions (IMC 0609 App. A)

Phase III Analysis Assumptions (IMC 0609 App. A)

• • HPCS will fail during suction transfer to the suppression pool HPCS will fail during suction transfer to the suppression pool

• • All potential initiating events affected except Station Blackout All potential initiating events affected except Station Blackout (SBO)

(SBO)

• • Exposure time is one year Exposure time is one year

• • No recovery of HPCS credited No recovery of HPCS credited

• • IPEEE information used to estimate fire risk contribution IPEEE information used to estimate fire risk contribution

• • Internal flooding risk contribution estimated with Clinton PRA Internal flooding risk contribution estimated with Clinton PRA information information Preliminary Greater than Green Finding and Apparent Preliminary Greater than Green Finding and Apparent Violation of 10 CFR 50, Appendix B, Criterion III, Violation of 10 CFR 50, Appendix B, Criterion III, Design Control, issued on November 29, 2006 Design Control, issued on November 29, 2006

Closing Remarks Closing Remarks Cynthia Pederson Cynthia Pederson Director Director Division of Reactor Safety Division of Reactor Safety