ML20011A704

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Responds to NRC 810608 Ltr Re Violations Noted in IE Insp Repts 50-254/81-04 & 50-265/81-04.Safe Shutdown Could Be Accomplished Independent of Fire by Local Manual Operation of Electromatic Relief Valves
ML20011A704
Person / Time
Site: Dresden, Quad Cities  Constellation icon.png
Issue date: 07/08/1981
From: Rausch T
COMMONWEALTH EDISON CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20011A700 List:
References
NUDOCS 8110290310
Download: ML20011A704 (2)


Text

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( j)'y Address Reply to: Post Othee Box 767

. Chicago, Ithnois 60690

-July 8, 1981' Mr.. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Poosevelt Road Glen Ellyn, IL 60137 l

Subject:

Quad Cities Units 1 and 2 Supplemental Response to Inspection Report 50-254/87-04 i and 50-265/81-04 Addressing Safe Shutdown Fire Analyses NRC Docket Nos.- 50-254/265 Reference (a): C. E. Norelius letter to C. Reed 1

dated June 1, 1981.

i (b): J. S. Abel letter to J. G. Keppier dated April 28, 1981.

Dear Mr. Keppler:

Reference (a) documented NRC receipt of the Commonwealth

, Edison response to the items of noncompliance identified in the subject Inspection Report, and requested an additional response concerning the effect upon safe shutdown analyses of a fire in the vicinity of certain non-fire rated hatches.

The enclosure to this letter contains our response to this request. It concludes that Quad Cities Units 1 and 2 could still be safely shutduwn in the event that a fire in a cable tunnel

' propogates through non-fire rated hatches in the turbine building 595' level.

Flease address any questions you may have to this office.

Very truly yours dbs-  %(

Thomas J. Rausch Nuclear Licensing Administrator Boiling Water Reactors Enclosure cc: Region III Inspector - Quad Cities im 2265N g@

8110290310 011023. 9 PDR ADOCK 05000237 .g$

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,,!,,. CCMONNEALTH EDISCN CCHPANY SUPPIDENTAL

, Response to Inspection Report 50-254/81-04 & 50-265/81-04 QUAD CITIES 1 & 2 "Can a fire in a cable tunnel propagate through non-fire rated hatch at turbine building floor elevation 595', and will such fire damage essential safe shutdown equipment in the turbine building?"

Response

A postulated fire in the Unit 1 Cable Tunnel would affect Divi-sion II cables only. If such a fire were to propagate through the unrated manhole at column / row 17/H, the only safe shutdown equipment located in the surrounding area are Division II cables in risers from the tunnel to the ground floor. Safe shutdown could be accomplished independent of such a fire by local manual operation of the electromatic relief valves in the Reactor Building and RHR System (Division I) in the LPCI and torus cooling modes.

The fire loading on the ground floor is.only 10,000 Btu /ft2, equivalent to a fire of less than 1/2 hour severity. All of the significant fire hazards on this floor, including the Reabtor

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  • Feedwater' tumps and the cable concentrations over' 4kV Eusses 11 and 12, are protected by automatic water suppression systems.

Automatic water suppression is also provided at the non-flammable EHC Fluid Reservoir, the trackway area, and cable penetration areas. ,

. A postulated fire in the Unit 2 Cable tunnel would affect cables of both safety divisions. If such a fire were to propagate through the unrated manhole at 17/G, the only safe shutdown equipment in the surrounding area are Unit 1 Division II cables as discussed above. Unit 2 shutdown could be accomplished independent of such a fire by local manual operation of the electromatic relief valves in the Reactor Building and RHR System in the LPCI and torus cooling modes. Unit 1 shutdown could be accomplished as described above.

If a fire in the Un3.t 2 cable tunnel were to propagate through the manhole at column / row 9/G-H, the only safe shutdown equipment in the surrounding area are Division II cable trays which run along Row G. Safe shutdown could be accomplished independent of such a fire by local manual operation of the electromatic,re-licf' valves in the Resctor Building and RHR System in the LPCI and torus cooling modes. All of the significant fire hazards on this floor, similar to the Unit 1 side, are protected by automatic water suppression systems.

Due to the low fire loading, 3" curbs around all manholes, auto-matic suppression systems, and independent safe shutdown capability, the postulated. spread of fire from either cable.. tunnel to the Turbine Building ground floor is not a significant event, and will not prevent safe shutdown of either unit.

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