ML060170075

Salem Generating Station - CO2 System Review, December 13, 2005

ML060170075
Person / Time
Site:	Salem, Hope Creek
Issue date:	12/13/2005
From:	Public Service Enterprise Group
To:	Office of Nuclear Reactor Regulation
References
Download: ML060170075 (18)

Text

• Scope of C02 Systems* System Operation* Design and Licensing Basis 0 C02 Concentration Issue 0 C02 Migration Issue* Summary Salem oHope Creek GENERATiNG SrATIONS 2

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-.. I. ,.I ' : 4.- I .I ,, ~ ..:6~1 ., i.- --. ~-~7 ,~,~ 1 4 ,' ~ ,-," ~ ,.- :: ~ --.~ ;I-m Owned by PSEG* Located in Southern New Jersey on River* Westinghouse 4-Loop PWRs* 1120 MWe Delaware* Unit 1 Operating* Unit 2 Operating License in 1976 License in 1980 SalrSAHope CreOk! GENERATI/NG STATIONS 3 A *; .- I,- ,;; :,?. -7 !M I,~. -1 C02 Areas within Scope of Discussion E 64' 4kV Switchgear Room M 84' 460V Switchgear Room 78' Electrical Penetration Room Other Areas with C02 E 1 00' Diesel Generator Rooms (3/unit)1 00' Diesel Generator Control Rooms (3/unit)m 84' Diesel Fuel Oil Storage Tank Rooms (2/unit)* 84' Diesel Fuel Oil Transfer Pump Rooms (2/unit)E Main Turbine Exciter (1/unit)SalemnjHope Creek GENERATING STATIONS 4 Figure of Salem Auxiliary Building 64 Foot Elevation Withheld under 10 CFR 2.390 5 Figure of Salem Auxiliary Building 84 Foot Elevation Withheld under 10 CFR 2.390 6 S?ktgnm of SPAY System lii~rft in 0 ;= .sr I-.;i--;e'@, B~d iR 2 l i W Wh s5w ;a-C-460 VAC Swit8bgwa..

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'034 _-* 1 an MTIWU fulitiff t ius OaAD MsS 5. 1 Sa&em4 Hope Creek GENERATING STATIONS 7 Design Basis of Systems Low pressure total area flooding C02 systems 64' 4kV Switchgear Rooms manually actuated 84' 460V Switchgear and 78' Electrical Penetration Rooms automatically actuated 50% concentration lAW NFPA 12 30 minute concentration hold time* Current NFPA 12 requirement 20 minutes Tank sized for two full discharges to largest area Salems), Hope Creek GENERATING STATIONS 8 SER for Amendment 11 -February 14, 1978* Implemented Technical Specifications for C02 Tank level and pressure PSEG Letter -September 26, 1978* PSEG committed to hold concentration for 30 minutes SER for Amendment 21 -November 20, 1979* C02 designed to flood protected areas to 50%* Manually actuated systems 1 Designed lAW NFPA 12 Supplement 6 of SER was adapted into original Unit 2 Operating License -May 20,1981 Salen'1Hope CSTATIO GENERATING STATIONS NRC approved exemptions from Appendix R, Ill.g62, for trains not separated by full one hour barriers Letter dated July 20, 1989 64' 4kV Switchgear Rooms-Included manual C02 actuation 84' 460V Switchgear Rooms* 78' Electrical Penetration Rooms Salem has no other C02 related exemptions Salen@Hope Creek'GENERATING STATIONS 10 64' 4kV Switchgear Rooms a Alternate Safe Shutdown n Reflected plant modifications into analysis to bring area to lll.g 3* Exemption no longer required E Retaining manual C02 84' 460V Switchgear Rooms m Alternate Safe Shutdown* Reflected plant modifications into analysis to bring area to Ill.g.3 i Exemption no longer required 78' Electrical Penetration Rooms* Normal Safe Shutdown* Area remains lll.g.2 M PSEG has completed fire wrap on cable trays* Eliminates one of two exemption issues M Maronite walls separate MCCs* Approved exemption still required SalemnI4 Hope Creek GENERATING STATIONS 11 1999 Self identified C02 concentration discrepancies Calculated room volumes not representative of actual Pre-operational tests in 64' 4kV Switchgear and 78' Electrical Penetration Rooms did not meet acceptance requirements NRC Violation issued February 14, 2000 2001 PSEG evaluated replacement of C02 suppression system with water in the 64' 4kV Switchgear Room r Design implementation issues precluded option selection 2002 Testing of C02 system performed Use of a tracer gas selected to support proposed design change to resolve C02 concentration SaleinrH2pe Creek GENER7ATING STATIONS 12 Immediate Actions Taken for System Operability El Firewatches in place Cause Identified Design Deficiencies

• Isolation dampers not leak tight design* Ventilation fans continue to operate Resulting Actions from Root Cause* Performed assessment applying NFPA 2001 methodology

• Determined concentrations are sufficient to suppress fire and allow for Fire Department response* Commitment change then License Amendment Request a Focused efforts on damper maintenance X Revisited response to Information Notice 99-05 Salenm§-2,,Hope Creek 13.GENERATING STATIONS 3 64' 4 kV Switchgear Rooms and 78' Electrical Penetration Rooms Meet the NFPA 2001 Methodology with Margin Completed Damper Maintenance and Testing 84' 460V Switchgear Room leakage remains higher than desired Firewatches in Place Safe Shutdown Capability Independent of C02 Areas have defense in depth-Early warning detection-On Site Fire Department Promptly Responds uSafe Shutdown Analysis assumes loss of all equipment in 64' 4kV and 84' 460V Switchgear Rooms u78' Electrical Penetration Rooms-Barrier to Barrier cable wrap-Partial Height Maronite walls between MCCs Salem~iZHope Creek 14 GENERATING STATIONS

Background

• Revisiting response to Information Notice 99-05 identified migration issue* Engineering study conservatively assessed migration paths* Study identified potential for C02 migration to areas requiring access for manual actions* Validated inputs and assumptions m Action taken based on results Cause Identified Design Deficiencies

• Pressure relief path not provided* Ventilation fans continue to operate causing differential pressures i Pressure is relieved by migration to surrounding areas SalemniD9 Hope Creek G ENERATHYG STATIONS 15 C02 Systems Isolated Compensatory Actions Established E Fire watches in place* Control of transient combustibles

• Control of Hot Work Safe Shutdown Capability Independent of C02* Areas have defense in depth-Early warning detection-On Site Fire Department Promptly Responds* Safe Shutdown Analysis assumes loss of all equipment in 64' 4kV and 84' 460V Switchgear Rooms* 78' Electrical Penetration Rooms-Barrier to Barrier cable wrap-Partial Height Maronite walls between MCCs SalemrrHope Creek GENERATING STATIONS 16 Multiple Solution Paths being Evaluated* Modifications to the current system / components

• Replacement with an alternate system* Application of risk informed methodologies

• Enhanced Modeling of C02 migration paths Evaluation of Solution Method -February 2006 Management Selection

-March 2006 Gen EAHope CrAOk GENERATING STATIONS 17 Some exemptions can be eliminated Concentration and Migration issues stem from design deficiencies Analytical and field actions were taken to resolve Compensatory measures provide conformance with licensing basis Multiple paths for resolution of issue being pursued One of Salem's key equipment issues to resolve PSEG will continue to communicate status SaIenmHope Creek GENERATING STATIONS 18