ML20214K007

Special Rept 86-13:on 860708 & 17,several Sprinkler Heads Identified as Blocked or Partially Blocked.Caused by Inadequate Design & Positioning of Heads.Surveillance Procedures Revised

ML20214K007
Person / Time
Site:	Rancho Seco
Issue date:	07/30/1986
From:	Julie Ward SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
86-13, JEW-86-262, NUDOCS 8608150269
Download: ML20214K007 (2)

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'$SMUD *%9 SACRAMENTO MUNICIPAL UTILITY DISTRICT O 62o1 S Street, P.O Box 15830. Sacramento CA 95852-1830. (916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA

" 31 fg lg g JEW 86-262

'EG;. .n July 30,1986 J B MARTIN REGIONAL ADMINISTRATOR REGION V 0FFICE OF INSPECTION AND ENFORCEMENT U S NUCLEAR REGULATORY COMMISSION 1450 MARIA LANE SUITE 210 WALNUT CREEK CA 94596 DOCKET NO. 50-312 SPECIAL REPORT NUMBER 86-13, SPRINKLER HEADS PARTIALLY BLOCKED The Sacramento Municipal Utility District hereby Special Report No. 86-13 in accordance with the Rancho Seco Nuclear Generating Station Technical Specifications Sections 3.14.3.2 and 6.9.5.E.

In two separate Occurrence Description Reports (0DR's), one dated July 8, 1986 and one dated July 17, 1986, it was reported that several sprinkler heads were identified as being blocked or partially blocked. The posi-tions of the sprinkler heads and associated surrounding equipment were such that a reduced efficiency or lack of adequate water coverage could be expected from those sprinkler heads. It should be emphasized that the deficient sprinkler heads account for only isolated portions of large sprinkler systems, and the remainder of the affected sprinkler systems remain fully operable. The sprinkler heads in question were dis-covered during weekly fire hazards inspections of Rancho Seco Buildings and grounds in accordance with AP.34A, Fire Hazards Inspections Guidelines.

The areas and sprinklers affected are specifically;

1) Sprinkler heads partially blocked by cable tray covers in Zone 81 and 82 of the Nuclear Service Electrical Building.

2) Sprinkler heads which are partially blocked between conduits in Corr-idor 103 on the grade level of the Auxiliary Building, Zone 43.

3) A portion of the sprinkler system protecting the grade level in Corridor 105 of the Auxiliary Building not being fully capable of protecting the corridor area because recently installed cable trays obstruct the sprinkler heads. These sprinklers are located in Zone 42.

8608150269 860730 PDR ADOCK 05000312 S PDR 0

i RANCHO SECO NUCLEAR GENERATING STATION O 14440 Twin Cities Road, Herald, CA 95638-9799; (209) 333-2935]g J

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SP 86-13 July , 1986 As a result of these identified deficiencies within fire Zones 81, 82, 42 and 43, the effected portions of these Zones have been declared technically

" inoperable" with regard to Technical Specification 3.14.3.2, and an hourly fire watch patrol has been established as required by the Technical Specifi-cation.

Each of the subject fire zones and associated sprinklers has been the sub-ject of a Nonconforming Report (NCR) and has been assigned to the Nuclear Engineering Department for disposition. Current scheduling by the Engi-neering Department provides for redesigning the affected systems through the Engineering Change Notice (ECN) system by the first of September 1986, and the physical modifications by the end of October 1986. In addition to the above physical modifications, a revision has been made to Surveil-lance Procedure SP.201.03I, Refueling Interval Fire Suppression System Surveillance (Sprinkler Systems and Hcse Stations). This revisien, re-designated SP.1000, Refueling Interval Inspection of Spray / Sprinkler Headers and Nozzles, gives specific guidance to ensure that Spray and/or Sprinkler Headers are free from blockage or disruption from equipment or structures within the zone. SP.1000 became effective July 14, 1986.

If there are any questions concerning this' report, please contact Mr. Ron W. Colombo at (916)452-3211,_ extension 4236 at the Rancho Seco Nuclear Generating tation.

. WARD DEPUTY GENERAL MANAGER, NUCLEAR cc: NRR