05000272/LER-1982-005, Forwards LER 82-005/01X-1.Detailed Event Analysis Encl

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Forwards LER 82-005/01X-1.Detailed Event Analysis Encl
ML20062C711
Person / Time
Site: Salem PSEG icon.png
Issue date: 07/21/1982
From: Midura H
Public Service Enterprise Group
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20062C713 List:
References
NUDOCS 8208050335
Download: ML20062C711 (3)


LER-2082-005, Forwards LER 82-005/01X-1.Detailed Event Analysis Encl
Event date:
Report date:
2722082005R00 - NRC Website

text

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b PSEG Public Service Electric and Gas Company P.O. Box E Hancocks Bridge. New Jersey 08038 Salem Generating Station July 21, 1982 Mr. R. C. Haynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406 Dear Mr. Haynes LICENSE NO. DPR-70 DOCKET NO. 50-272 REPORTABLE OCCURRENCE 82-05/0lX-1 SUPPI" MENTAL REPORT Pursuant to the requirements of Salem Generating Station Unit No. 1 Technical Specifications, Section 6.9.1.9.b, we are submitting supplemental Licensee Event Report for Reportable Occurrence 82-05/0lX-1.

Sincerely yours, llVilt:

H. J. Midura General Manager -

Salem Operations RF:ks f4 CC: Distribution 1

8208050335 820721 PDR ADOCK 05000272 S pon The Energy People $6 ,,

Report Number: 82-05/0lX-1 Report Date: 07-21-82 Occurrence Date: 01-31-82 Facility: Salem Generating Station, Unit 1 Public Service Electric & Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Degradation of Fuel Cladding.

This report was initiated by Incident Report 82-023.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 6 - Rx Power 0% - Unit Load 0 MWe DESCRIPTION OF OCCURRENCE:

On January 31, 1982, the Westinghouse Fuel Inspection Team, while conducting their fuel assembly TV visual and dimensional survey, in accordance with the Planned Fuel Inspection (FP-PSE-FE4) of two optimized assemblies and four additional assemblies, discovered degradation of the fuel cladding on fuel assembly C-04. Based on the video inspection, a fuel pin rupture was observed on fuel pin 9, face 2, fuel assembly C-04, between grid 7 and 8. The assembly C-04 core location for Cycle 3 was F-06. The inspection team reported that fuel pellets were visible during the fuel element scan.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

The cause of the fuel pin rupture was diagnosed as excessive rod growth due to fuel lockup. A fuel pellet was wedged in the top several inches of the fuel column, resulting in excessive diametri-cal strain and swelling. Rod growth was due to Pellet Clad Material Interaction (PCMI)/Ratcheting and Neutron Elongation. Internal tube stress and fission product iodine created crack initiation via stress cracking corrosion. Secondary hydriding completed the failure mode.

ANALYSIS OF OCCURRENCE:

The Westinghouse investigation of the cladding failure produced the following results: the remainder of the assembly showed normal crud buildup and burnup condition. The rod adjacent to and in contact with the failed rod did not fail. The failed rod grew most in Cycle 2 and continued to grow in Cycle 3. The total growth of the failed rod, S/N 09, at the End of Cycle 3, (EOC-3), was 1.0% as compared to .56% for the assembly average.

(_

LER 82-05/0lX-1 .

ANALYSIS OF OCCURRENCE: (continued)

After their reexamination of the EOC-3 video inspection results and the EOC-2 Inspection Report (WCAP 9874), Westinghouse indicated that evidence of a problem had existed. Rod swelling was detected at EOC-2, not rod misalignment as reported in WCAP 9874. Operating chemistry showed that Iodine 131 and 138 were mismatched at EOC-2 and 3, indicating a probable fuel element failure, and hydride lines were evident around contact areas on Rod S/N 09 at EOC-2.

CORRECTIVE ACTION:

Fuel assembly C-04, which was scheduled to be removed from the core, was placed in the spent fuel pit. As a result of the C-04 inspection results, all C assemblies scheduled to be reused in the core, were inspected. Ten additional assemblies were also inspected. No additional cladding ruptures were discovered.

Westinghouse conducted an evaluation of the cladding failure, and found fuel lockup to be the primary cause. Based on the results of the inspection of the other fuel assemblies, and the results of the Westinghouse evaluation, the following conclusion was reached: Due to the large number of fuel pins in the core, and the lack of similar occurrences of cladding failure in the fuel assemblies inspected, this occurrence is considered to be isolated in nature. No further corrective action is deemed necessary.

FAILURE DATA:

Westinghouse Electric Corporation Fuel Assembly Prepared By R. Heller h~

Genehal Manager -

Salem Operations SORC Meeting No. 82-69