ML20095F597
| ML20095F597 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/12/1995 |
| From: | Stetz J CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR 2344, NUDOCS 9512190121 | |
| Download: ML20095F597 (4) | |
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9 CENTER 00R ENERGY l
300 Modison Avenue John P. Steer Toledo OH 43652 0001 Vice President Nuclear 1
419-249 2300 Davis-Besse Docket Number 50-346 I
License Number NPF-3 Serial Number 2344 i
4 December 12, 1995 i
United States Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555-0001
Subject:
Additional Information for The Summary Report for Resolution of Unresolved Safety Issue A-46
Reference:
USI A-46 Evaluation for the Davis-Besse Nuclear Power Station submitted under Toledo Edison Letter Serial Number 2316, Dated August 29, 1995 Ladies and Gentlemen:
During a November 1, 1995, telephone conference call with Ms. L. L. Gundrum and Mr. K. D. Desai of the Nuclear Regulatory Commission (NRC) Staff, Toledo Edison (TE) was requested to provide additional information regarding the Summary Report for Resolution of Unresolved Safety Issue A-46 submitted for the Davis-Besse Nuclear Power Station. Attachment 1 to this letter details the information requested and TD s corresponding responses.
Should you have any questions or require additional information, please contact Mr. Peter W. Smith, acting Manager - Regulatory Affairs, at (415) 321-7744.
Very truly yours, Attachment cc:
L. L. Gundrum, DB-1 NRC/NRR Project Manager H. J. Miller, Regional Administrator, NRC Region III S. Stasek, DB-1 NRC Senior Resident Inspector Utility Radiological Safety Board 9512190121 951212 g
PDR ADOCK 05000346 P.
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operating Companies
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Cleveland Electnc itiuminot:ng Toledo Edison
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Docket Number 50-346 License Number NPF-3 Serial Number 2344 Att'achment 1 Page 1 REQUEST FOR ADDITIONAL INFORMATION REGARDING
SUMMARY
REPORT FOR RESOLUTION OF UNRESOLVED SAFETY ISSUE A-46 FOR THE DAVIS-BESSE NUCLEAR POWER STATION 1.
Provide a complete list of sources of water (tanks, etc.), their capacities, and whether or not they are seismically qualified.
In the report you mention the Borated Water Storage Tank (BWST), Boric Acid Addition Tanks (BAAT), Makeup Tank, and Service Water System.
Are there any other sources which you may want to use? What is the order of preference for primary-side and secondary-side sources of water? What is the order of preference for secondary-side water sources during a Loss of Offsite Power? Are the instruments used for automatic switching of the Auxiliary Feedpumps from the Condensate Storage Tank to the Service Water System seismically qualified?
Response
Toledo Edison's (TE's) Unresolved Safety Issue (USI) A-46 Summary Report provides a list of seismic tanks for which credit is taken in the two shutdown paths (primary and backup). Non-seismic sources of water would be utilized, if available.
Primary-side tanks with capacities and seismic classification are listed below in order of preferential use:
TANK CAPACITY SEISMIC CLASSIFICATION (GAL)
Makeup 2,800*
Seismic #
BWST 482,778***
Seismic #
BAAT (2) System 5,500**
Non-seismic #
Core Flood (2) 7,555/ tank ***
Seismic ##
- Normal Operating Level j
- Technical Specification Minimum Total Volume
@ 13000 ppm Boron
- Technical Specification Minimum
- SQUG SSEL
- IPEEE SSEL Secondary-side tanks with capacities and seismic classification are listed in order of preferential use:
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a Docket Number 50-346 License Number NPF-3 Serial Number 2344 Att'achment 1 Page 2 TANK CAPACITY SEISMIC CLASSIFICATION (GAL)
Deaerator (2) 53,000/ tank **
Non-seismic Condenser Hotwell 80,000**
Non-seismic l
Condensate Storage Tanks (2) 250,000*
Non-seismic 450,000**
Service Water See Note 1 See Note 1 Note 1: Service Water System (SWS) is supplied from Lake Erie. The Ultimate Heat Sink portion of SWS at minimum water level and maximum temperature has sufficient capacity to supply 30 days of cooling water to safety related equipment without exceeding the equipments' design basis temperature.
Applicable portions of SWS are seismic and part of the SQUG SSEL
- Technical Specification Minimum Contained Volume (total of both tanks)
- Normal Operating Contained Volume For secondary-side tanks during Loss of Offsite Power, the deaerator tanks and the condenser hotwell would not be available.
The Steam Generators would be fed by the steam-driven Auxiliary Feedpumps with a water source from the Condensate Storage Tank with automatic switching to the Service Water System on low level in the Condansate Storage Tank. The Auxiliary Feedpump Suction Pressure Interlocks (PSL 4928A and B, and 4929A and B) are seismically qualified and listed on the SOUG SSEL.
2.
Are you planning on using the " Feed and Bleed" method as addressed in the emergency operating procedures for decay heat removal? Are all components in the " feed and bleed cooling" path seismically quali-fled?
Response
Feed and bleed cooling is directed in the Emergency Operating Pro-cedure when Steam Generator heat transfer is not available.
This mode of heat transfer would allow cooldown until the normal Decay Heat Removal System could be placed in service.
Feed and bleed cooling would be established with a water source from the BWST fol-lowed by Containment Sump recirculation. All components in the feed and bleed cooling path are seismically qualified.
However, feed and bleed cooling is not part of the DBNPS licensing basis and is not discussed or credited in the TE USI-A46 Summary Report as one of the two paths for reaching Hot Shutdown (Mode 3).
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Docket Number 50-346 License Number NPF-3
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Serial Number 2344 Att'achment 1 Page 3 3.
In Section 4.3 (Pg. 22 last paragraph) you stated "Although direction to use Safe Shutdown Equipment and Instrumentation was not always provided as the primary procedure flowpath, no procedural flowpaths were identified that would prevent a trained licensed operator from completing the cooldown to the Hot Shutdown condition." Can you elaborate on this? Do procedures exist for the paths that you high-lighted in the report or are you relying on operators to accomplish these paths?
Response
The symptom-based Emergency Operating Procedure (EOP), DB-0P-02000, j
" Reactor Protection System, Safety Features Actuation System, Steam j
and Feedwater Rupture Control System Trip or Steam Generator Tube Rupture," provides direction to the operators for operation of equip-l ment following a seismic event that results in a reactor trip. With only Safe Shutdown Equipment List (SSEL) components available, this E0P provides complete guidance to achieve Cold Shutdown (Mode 4).
The SSEL paths are a subset to the existing EOP flowpaths.
In addition to DB-OP-02000, the Off Normal Procedure, RA-EP-02820, l
" Earthquake," provides additional guidance with respect to Safe Shutdown Equipment and other auxiliary equipment. This procedure would also be utilized by the operating staff during a seismic event.
The operators are not required to develop flowpaths utilizing SSEL components.
4.
Explain the difference between Appendix B, Composite SQUG Safe Shut-down Equipment List (SSEL), and Appendix C, Seismic Review Safe Shutdown Equipment List (SSEL), to the Summary Report.
Response
Appendix B, Composite SQUG Safe Shutdown Equipment List (SSEL) is an alpha-numeric listing of all equipment identified in the two trains associated with placing the plant in a safe shutdown condition. This composite listing includes equipment required to be reviewed for seismic adequacy (S), relay actuation (R) or both seismic adequacy and relay actuation (SR).
For completeness the composite SSEL also includes equipment on the safe shutdown train that is not required to be walked down as this equipment has been determined by SQUG to be
" rugged".
Appendix C, Seismic Review Safe Shutdown Equipment List (SSEL), is a subset of Appendix B and includes only those items requiring a seis-mic review. This appendix was ge erated by performing a sort on Appendix B for equipment required t, be reviewed for seismic adequacy (S) or both seismic adequacy and relay actuation (SR).