ML080250274

Oconee - Handouts from 1/24/08 Meeting

ML080250274
Person / Time
Site:	Oconee
Issue date:	01/24/2008
From:	Duke Power Co
To:	Office of Nuclear Material Safety and Safeguards
References
GL-96-006
Download: ML080250274 (15)

Text

,Duke!PowerA Duke Energy Company Oconee Nuclear Station.GL 96-06 Resolutions January 24, 2008 MkDuke fEPowerA Duke Energy Company Agenda-m Introductions m Purpose of Meeting m GL 96-06 Background m Modification

• Technical Specifications/Selected Licensee Commitments

• Summary 2 MkDuke EFPowerA Duke Energy Company Introductions I U Technical Support* Henry Harling -Modifications

-. Mechanical

• Tom Glenn -Modifications

-Electrical

• Tim Brown -Design Basis Group* -Vance Bowman -Modifications-Mechanical Supervisor

• Patsy Earnhardt

-Modifications-Project Manager--*] Ed Burchfield

-RES Manager n Regulatory Compliance

• Reene' Gambrell -Licensing Engineer 3 Duke ,PowerA Duke Energy Company Purpose U Discuss background of the project.U Discuss modification.

• Discuss associated technical specifications/selected licensee commitments.

U Discuss commitments and approval timeframe.

4 P Duke EhPowere A Duke Energy Company GL 96-06 Background

ý17 7" Thermal overpressurizatior isolated penetrations

-Cor U Two phase heat transfer of RBCUs -Complete.of nplete.Waterhammer.

5 wDukew=6B c go-n ADuko GL 96-06 Background (cont'd)* Timeline: " NRC GL 96-06 released September 1996.-ONS operability assessment completed January 1997.* ONS detailed operability evaluation completed February 1999.* EPRI GL 96-06 waterhammer methodology approved April 2002.* ONS letter to NRC describing operability evaluation and planned modifications September 2002.6 DGL 96-06 Background A ueEnoergyCmay (cont'd)* ONS Operability Evaluation:

• Significant Work. Scope.* Waterhammer magnitudes determined by Method of Characteristics (MOC) approach.* MOC methodology validated versus EPRI program.* Credit taken for presence of non-condensables by altering speed of sound.* Joukowsky's equation with the modified speed of sound was then used to predict waterhammer magnitudes.

• 7

Duke GL 96-06 Background A Duke Energy Company (cont'd)EONS Operability Evaluation (cont'd)

* Results of MOC used to construct force time histories input into stress -analysis.

• Evaluated approximately 300 piping.support/restraints per unit.* ASME Code Section III, Appendix F used as acceptance criteria.* Results indicated no pressure boundary failures.8 1PDuke rE Powere A Duke Energy Company GL 966-06 Background (cont'd)LPSW System RESOLUTION STATUS Waterhammer Vulnerabilities Failure of running LPSW Modification to install LPSW Standby pump auto- COMPLETE pump to restart following start circuitry to start LPSW standby pump LOOP. following LOOP event in which running LPSW pump does not restart.Voiding of Reactor Modification to relocate the connection between COMPLETE Building Auxiliary the trains outside containment, provide fast Cooling. Units due to high isolation capability on low LPSW pressure and elevation, provide relief valves adjacent to the containment penetrations to prevent thermal overpressurization".

Drainage of the LPSW Modification to install check valves in LPSW Pending review system which includes supply header and automatic pneumatic and approval by LPSW piping servicing discharge isolation valves, controllable vacuum NRC the Reactor Coolant breaker valves, and associated circuitry in LPSW. U2 -Fall 2008 Pumps return header to isolate Engineered Safeguards.

U3 -Spring 2009 portions of the LPSW system to mitigate waterhammers.

AkDuke EIPowerA Duke Energy Company Modification m System designed to prevent waterhammers following:

m LOOP, LOCA/LOOP, and MSLB/LOOP.

m Analysis determined LOOP only events are more limiting.m LPSW Waterhammer Prevention Modification:

m New components in LPSW supply headers to RBCUs, RBACs, and RCP motor coolers.m Check valves.m Isolation valves and test connections.

m Logic circuitry:

,,4 Analog Channels.m 2 Digital Channels.10 MkDuke Wf PowerA Duke, Energy Company Modification (cont'd)*.New components in LPSW discharge headers from RBCUs, RBACs, and RCP motor coolers: miCommon cooling water return piping divides into two parallel headers.m Two pneumatic discharge isolation valves installed in each header.m *Two controllable vacuum breakers installed in parallel on common header downstream of pneumatic discharge isolation valves.mThermal relief valves.11 A Duke WPowerA Duke Energy Company Modification (cont'd)* System

Description:

• Actuates on low, decreasing LPSW Supply Header pressure.,* Resets on increasing LPSW Supply Header pressure.* Setpoints selected and offset to prevent inadvertent actuation or reset.* Single Failure Proof- Design.* System is fully automatic.

• . Boundary Valve Leakage Allowance.

• Pneumatic Valve Accumulators.

12 IADuke.W.FPowere A Duke Energy Company Technical Specifications F Reset portion of circuitry and system meets criterion 3 of 10 CFR 50.36.ZOne new Technical Specification E] TS 3.3.27, LPSW RB Waterhammer Prevention Reset Circuitry.

U One revised Technical Specification TS 3.6.5, revised to address pneumatic discharge isolation valves.13 Mk,Duke W.Power Selected License A Duke Energy Company Comm im en ts E SLCs to address Waterhammer.

• Isolation function of circuitry." Vacuum Breakers." Isolation function of Isolation Valves.U Controlled through internal processes.

14 Duke EPowere A Duke Energy Company Summary* One modification remains to resolve issue.-NRC approval of LAR necessary to support modification installation beginning Fall 2008.* Proposed change improves plant safety.* Duke committed to support NRC review and approval." Conference Calls." Additional Meetings.15