ML19291A885

LER 79-027/01T-0 on 790807:four Seismic restraints,NZ-2-R5 NZ-2R7,NZ-2-R8 & NZ-2-R9,in Positions Other than Required by Original Design.Caused by Improper Installation & Damage Due to Unrestrained Pipe Movement

ML19291A885
Person / Time
Site:	Oyster Creek
Issue date:	08/21/1979
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML19291A877	List: ML19291A876 ML19291A885
References
LER-79-027-01T, LER-79-27-1T, NUDOCS 7908280701
Download: ML19291A885 (3)

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7 8 0C C1 DOCKET NU'/ seq EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h o 2 On August 7, 1979, during an inspection of seismic restraints associated l g 3 g with Core Spray System 11, four seismic restraints, NZ-2-RS, NZ-2-R7, g g , ,NZ-2-R8, and NZ-2-R9, were discovered in positions other than required by j

[g s  ; original design or had failed. On August 8, 1979 two more restraints,  ;

, ,q ,NZ-2-R6 and NZ-2-R6A, were found to be in a condition not representative  ;

l0 7 l of the original design criteria. Core Spray System !! was considered j

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44 47 CAUSE DESCRIPT60N AND CORRECTIVE ACTIONS h qT] l Four of the restraints were found to be installed contrary to original  ;

, ,  ; design criteria and beCause of this two others were damaged due to un-  ;

restrained pipe movement in other sections of the piping. Four of the ,

restraints were restored to their designed condition. NZ-2-R7 des-3 3 4 j ign was modified. NZ-2-R6 will be restored to original design or relocated. g 83 i 8 3 F /.C it i T Y P/ETHOD CF STAlsi . PC'/ E R OT HER STATUS D;SCOVERY D:SCOVERY DESCRtPTION 3.

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6 OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/79-27-lT Report Date August 21, 1979 Occurrence Date August 07, 1979 Identification of Occurrence Discovery of six seismic restraints for the 6-inch core spray test line, which were either in positions other than required by original design criteria or had failed. This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.a.9 Conditions Prior to Occurrence The plant was operating at steady-state power.

Power: Core 1909.16 Mut Electric 639 MWe Flow: Recirculating 15 2 x 104 gpm Feedwater 7.143 x 105 lb/hr Stack Gas Activity: 27,900 pci/sec Description of Occurrence On Tuesday, August 7,1979, during an inspection of seismic restraints associated with Core Spray System II, it was determined that two seismic restraint (NZ-2-R5 and n9) clamps were not in thei r as-buil t posi tion. Additionally, one restraint, NZ-2-R7, was found to have its wall attachment bolts sheared, rendering this restraint inoperable. The structural configuration of the fourth restraint, NZ-2-R8, was found to have been al tered. All of the restraints are connected to the 6-inch test line for Core Spray System II. Because of the configuration and condition of four restraints, System 11 was considered inoperable at this time until further analyses could be performed.

After returning the above four restraints to their as-designed status on August 8, 1979, two more restraints, NZ-2-R6 and R6A, were found to be in a condition not representative of original design criteria. The condition of these two restraints alone did not justify declaring System 11 inoperable at this time.

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Re or:able 0:currence fio. 50-219/79-27-1T Page 2 August 21, 1979 Apparent Cause of Occurrence Four of the seismic restraints, NZ-2-R5, R6, R6A, and R9, were found to be installed contrary to original design criteria. Because of the failure to install the above restraints properly, restraints NZ-2-R7 and NZ-2-R8 were damcged due to unrestrained pipe movement in other sections of the piping.

Analysis of Occurrence The 6-inch test piping routes water in the core spray system from the discharge of the core spray booster pumps through a motor operated test isolation valve located close to the core spray 1ine, a check valve located in the area of the torus and into the torus. Failure of the restraints during a seismic event could have produced a failure of the test line at some point between the motor operated test isolation valve and the c' 2ck valve. The significance of this event is that core spray system function would not have been impaired by the failure. Primary containment would be maintained by the reliance on a single check valve. The check is not part of the local leak rate testing program since normally it does not serve as a primary containment isolation barrier. Therefore, the integrity of this valve is not known.

x rective Actlon_

All restraints were restored to their designed condition with the exception of restraint NZ-2-R7 and NZ-2-R6. IlZ-2-R7 design was modified to provide easier placement of anchor bolts. Core Spray System I was on an accelerated surveillance test schedule until System 11 was declared operable. NZ-2-R6 will be restored to original design or relocated based on radiation levels in the reactor cleanup filter sludge tank room.

Failure Data Piping restraints designed by: Bergen Patterson Pipe Support Company Clifton, NJ

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