05000272/LER-1981-007, Forwards LER 81-007/01X-1.Detailed Event Analysis Encl

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Forwards LER 81-007/01X-1.Detailed Event Analysis Encl
ML18085B094
Person / Time
Site: Salem PSEG icon.png
Issue date: 03/20/1981
From: Uderitz R
Public Service Enterprise Group
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML18085B095 List:
References
NUDOCS 8103310626
Download: ML18085B094 (4)
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LER-1981-007, Forwards LER 81-007/01X-1.Detailed Event Analysis Encl
Event date:
Report date:
2721981007R00 - NRC Website
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PS~G Public Service Electric and Gas Company 80 Park Plaza Newark. N.J. 07101 Phone 201 /430-7000 Mr. Boyce H. Grier Director of USNRC March 20, Off ice of Inspection and Enforcement Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

LICENSE NO. DPR-70 DOCKET NO. 50-272 REPORTABLE OCCURRENCE 81-07/0lX-l SUPPLEMENTAL REPORT Pursuant to the requirements of Salem Generating Station Unit No. 1 Technical Specifications, Section 6.9.1, we are submitting supple-mental Licensee Event Report for Reportable Occurrence 81-07/0lX-l.

Sincerely yours,

/

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R. A. Uderit:.z*

General Manager -

Nuclear Production CC:

Director, Office of Inspection and Enforcement (30 copies)

Director, Office of Management Information and Program Control (3 copies)

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Report Number:

81-07/0lX-l Report Date:

March 20, 1981 Occurrence Date:

1/19/81 Facility:

Salem Generating Station -

Unit l Public Service Electric and Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Safety Injection Throttle Valves not in Required Positions CONDITIONS PRIOR TO OCCURRENCE:

Mode 3 -

Hot Standby DESCRIPTION OF OCCURRENCE:

At 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on January 19, 1981, the NRC Resident Inspector requested that the following throttle valves which balance flow through the Safety Injection Loops be inspected to verify Lhat they were all in their required positions; 11SJ16, 12SJ16, 13SJ16, 14SJ16, llSJ143, 12SJ143, 13SJ143, 14SJ143, llSJ138, 12SJ138, 13SJ138 and 14SJ138.

The following valves were not in their required positions; 14SJ16, 11SJ138, 12SJ138 and 13SJ138.

This occurrence requires prompt notification to the NRC with a written followup required in fourteen days IAW Technical Specification 6.9.1.8.f.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

Combination of procedure inadequacy and personnel error.

ANALYSIS OF OCCURRENCE:

Valve No. 14SJ16, a cold-leg throttling valve controlling flow from the Centrifugal Charging/Safety Injection (C/SI) pumps, was found to be one turn further opened than intended (4-1/3 turns open instead of the 3-1/3 turn required).

The effect of this would be to make the No. 14 cold-leg injection flow higher than the other three legs.

If a. small-break LOCA were to be postulated as this injection line fracturing at the RCS connection, a greater loss of injection water would be spilled (not reach the core) due to the lower cold-leg line resistance.

It is difficult to quantify the amount of additional fluid loss unless a field test is performed.

However, due to the substantial margin in peak cladding temperatures (PCT) found in the FSAR analysis of small-break LOCA, it is the judgment of both Westing-house Electric Corporation and PSE&G that the conditions created by the 14SJ16 valves being one turn further open would not cause

LER 81-07/0lX-l 2 -

March 20, 1981 an unsafe condition.

Should a large-break LOCA occur elsewhere in the RCS, no detrimental affects would be noticed by virtue of the 14SJ16 valve being further open because the C/SI pumps are not the major or dominant source of water to the core in such a break.

It should be noted that the position of the 14SJ16 valve was in a region where a significant change in flow resistance would occur for each turn of the valve handwheel.

However in PSE&G's judgment, the condition of this one valve would not have placed the plant in an unsafe condition.

Three valves on the hot-leg injection lines were also found to be mispositioned.

The 11SJ138 valve was approximately 1/2 turn further open, the 13SJ138 valve was one full turn further open, and the 12SJ138 valve was found to be several turns further closed than required.

Again, it would be difficult to quantify the net effects of the two valves being further open and one valve being further closed than intended, unless a test is performed in the field.

However, after consultation with Westinghouse Electric Corporation, PSE&G has come to the conclusion that the misposition of these valves would not have placed the plant in an unsafe condition.

Our basis for this is that by the time hot-leg injection begins, the flow requirements into the core are not large and can be met with the valves in a wide range of positions.

Secondly, although the lines would be somewhat imbalanced, this per se has little or no effect on the core due to mixing in the reactor vessel.

Last, the two valves being slightly further open compensate for the one valve being further closed, for a net effect which is probably negligible.

Again, Westinghouse Electric Corporation concurs with our judgment.

Based on consultation wi.th Westinghouse Electric Corporation and our own examination of the situation, PSE&G concludes that the Salem Unit No. 1 was not in an unsafe condition due to the refer-enced valves being mispositioned.

This conclusion extends only to this specific occurrence and would not necessarily be applicable to any other incident of this type.

For this specific occurrence, PSE&G believes that the Salem plant was not in an unsafe condition, and is satisfied that steps have been taken to correct the immediate situation and to prevent a reoccurrence.

CORRECTIVE ACTION

Valves 14SJ16, 11SJ138, 12SJ138 and 13SJ138 were immediately placed in their required positions.

To insure that all the throttling valves in this system are returned to their exact required positions following any evolution required by a valve lineup, on-the-spot changes have been made to the appropriate procedures.

LER 81-07/0lX-l 3 -

March 20, 1981 FAILURE DATA:

Not Applicable Prepared By W. J. Steele SORC Meeting No.

Sl-15

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