ML20248B936

Safety Evaluation Supporting Amend 107 to License DPR-54

ML20248B936
Person / Time
Site:	Rancho Seco
Issue date:	06/05/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20248B921	List: ML20248B919 ML20248B931 ML20248B936
References
NUDOCS 8906090214
Download: ML20248B936 (2)

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k- UNITED STATES

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' NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555

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's SAFETY. EVALUATION.BY THE 0FFICE OF. NUCLEAR kEACTOR. REGULATION SUPPORTING. AMENDl4ENT-NO.107 T0. FACILITY.0PERATING LICENSE-DPR.54 RANCHO.SECO. NUCLEAR GENERATING. STATION,. UNIT 1 DOCKET.NO. 50-312

1.0 INTRODUCTION

By letter dated October 25, 1988, the Sacramento flunicipal Utility District (SMUD) raquested a change to the Technical Specifications of the-Rancho Seco Nuclear Generating Station to remove the requirements for carbon cioxide fire suppression systems in fire zones 75, 76, 77, 78, 79 and 80 from Table 3.14-3. This change removes carbon dioxide fire suppression systems from those Nuclear Service Electrical Building (NSEB) zones required to be operable by Technical Specification 3.14.4.

2.0 EVALUATION The flRC staff has evaluated the proposed changes and has concluded that they are acceptable. The staff's evaluation is given below.

The proposed technical specification change affects the NSEB fire protection system. This change allows permanent disabling of the carbon dioxioe fire suppression system for the switchgear, electrical equipment and battery rooms in the NSEB. The NSES is a reinforced concrete structure which houses equipment and support systems for the A2 and B2 essential distribution systems. Equipment and cabling for the A2 Train and the B2 Train are located on opposite sides of the NSEB and are separated by an eight foot corridor with three-hour rated fire walls on each side. Neither Appendix A to Branch Technical Position (BTP) APCSB or Section III.G.2 of Appendix R to 10 CFR Part 50 require the carbon dioxide system in zones 75 through 80 because the redundant shutdown systems are separated by three-hour fire walls.

The combustible leading in each of the affected areas is low. The loading within the subject fire areas consists primarily of fire retardant cable and battery casing plastic. The fire hazards within the building are isolated by the division of the NSEB into distinct fire areas, separated by rated fire barriers. Redundant equipment within the NSEB is additionally separated by the central corridors, which are protected by smoke detectors.

and a wet-pipe sprinkler system. Therefore, a fire in any zone would affect only one train and the redundant train would not be affected by the fire.

The adequacy of the fire suppression capability within the NSEB is not  ;

affected by this change. The existing fire detection system will remain operational in the affected zones. Smoke and thermal detectors are installed in each area to provide early warning alarm in the control room for prompt 8906090214 890605 gDR ADOCK 05000312 PDC

fire brigacie response and manual fire fighting.

The licensee's fire hazards analysis demonstrates that the construction features, low combust ible loadings, and equipment layout within the NSEB serve to lim potential fire damage without reliance on automatic suppress'on.it The zones affected do not require automatic suppression systems.

Specification 3.14 for Rancho Seco Nuclear Generatin supporting analysis as provided by SMUD.

systems in fire zonestechnical specification requirement for carbon dioxid 75, 76, 77, 78, 79 and 80. As discussed in the and meets the applicable regulatery requirements. preceeding p 3.0 CONTACT.WITH STATE OFFICIAL The NRC staff has advised the Chief of the Radiological Health Branch determination of no significant hazards consideration. State D received. No comments were

4.0 ENVIRONMENTAL CONSIDERATION

This amendment involves changes in the insta.llation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the anendment involves no significant increase in the amounts, and no significant change in the types, of any effluents tb t may be released offsite, and that there 1s no significant increase in individual or cumulative occupational radiation exposure.

The Commission has previously issued a proposed finding that this anendmen involves coment on no suchsignificant finding. hazards consideration and there has been no public criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).A Pursuant to 10 CFR 51.22(b), no environmental impact statement or of this amendment. environmental assessment need be prepared in connection with 5.0 . CONCLUSION Wehaveconcluded,basedontheconsiderationsdiscussedabove,that(1) there is reasonable assurence that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities willand regulations, be conducted 3 in compliance with the Commission's to common defense the issuance of thesecurity (an)d amendment orwilltonot thebe health inimical and safe Principal Contributor: S. Juergens Dated: June 5, 1989

. fire brigade response and manual fire fighting. The licensee's fire hazards analysis demonstrates that the construction features, low combust-ible loadings, and equipment layout within the NSEB serve to limit potential fire damage without reliance on automatic suppression. The zones affected do not require automatic suppression systems.

In summary, the NRC staff has reviewed the proposed change to Technical  !

Specification 3.14 for Rancho Seco Nuclear Generating Station, and the supporting analysis as provided by SMUD. The proposed change deletes the technical specification requirement for carbon dioxide fire suppression systems in fire zones 75, 76, 77, 78, 79 and 80. As discussed in the preceeding paragraphs, we find that the proposed change is acceptable, and meets the applicable regulatory requirements.

3.0 CONTACT.WITH STATE OFFICIAL The NRC staff has advised the Chief of the Radiological Health Branch, State Department of Health Services, State of California, of the proposed determination of no significant hazards consideration. No comments were received.

4.0 ENVIRONMENTAL CONSIDERATION

This amendment involves changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the anendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is.no significant increase in individual or cumulative occupational radiation exposure.

The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comrrent on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuantto10CFR51.22(b),noenvironmental1mpactstatementor environmental assessment need be prepared in connec' ..n with the issuance of this amendment.

5.0 CONCLUSION

We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, such (2) public activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to common defense and security or to the health and safety of the public.

Principal Contributor: S. Juergens Dated: June 5, 1989

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