ML19211C678
| ML19211C678 | |
| Person / Time | |
|---|---|
| Issue date: | 01/02/1980 |
| From: | Carroll D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wright G ILLINOIS, STATE OF |
| References | |
| NUDOCS 8001140186 | |
| Download: ML19211C678 (2) | |
Text
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION TD o
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REGION 111 0,
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799 ROOSEVELT ROAD
,e GLEN ELLYN, ILLINOIS 60137 JAN 2 198()
State of Illinois Department of Public Health ATTN:
Mr. Gary N. Wright, Chief Division of Nuclear Safety 535 West Jefferson Street Springfield, IL 62761 Gentlemen:
The enclosed IE Information Notice No. 79-37 titled " Cracking in Low Pressure Turbine Discs" was sent to the following licensees on December 28, 1979:
American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Cincinnati Gas & Electric Company Zimmer (50-358)
Cleveland Electric Illuminating Company Perry 1, 2 (50-440, 50-441)
Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
Dresden 1, 2, 3 (50-10, 50-237, 50-249)
La Salle 1, 2 (50-373, 50-374)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Consumers Power Company Big Rock Point (50-155)
Midland 1, 2 (50-329, 50-330)
Palisades (50-255)
Dairyland Power Cooperative LACBWR (50-409) 1749 278 Detroit Edison Company d-Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462) 8 () U 1 14 0 l
JUI I State of Illinois -
Iowa Electric Light & Power Company Duane Arnold (50-331)
Northern Indiana Public Service Company Bailly (50-367)
Northern States Power Company Monticello (50-263)
Prairie Island 1, 2 (50-282, 50-306)
Ohio Edison Company Erie 1, 2 (50-580, 50-581)
Public Service of Indiana Marble Hill 1, 2 (50-546, 50-547)
Toledo Edison Company Davis-Besse 1 (50-346)
Union Electric Company Callaway 1, 2 (50-483, 50-486)
Wisconsin Electric Power Company Point Beach 1, 2 (50-266, 50-301)
Wisconsin Public Service Corporation Kewaunee (50-305)
Sincerely, t
W Dorothy E Carroll, Acting Chief Administr ive Branch
Enclosure:
IE Information Notice No. 79-37 cc w/ enc 1:
Mr. D. W. Kane, 4} ]g Sargent & Lundy Central Files Reproduction Unit NRC 20b Local PDR NSIC TIC
UNITED STATIS ISINS NO.:
6870 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7910250525 WASHINGTON, D.C.
20555 December 28, 1979 IE Information Notice No. 79-37 CRACKING IN LOW PRESSURE TURBINE DISCS Description of Circumstances:
An anonymous letter was received by the Director of the Office of Inspection and Enforcement, on November 17, 1979 which alleged possible violation of Part 10 CFR 50.55e and/or 10 CFR 21 Regulations concerning reportability of recently discovered stress corrosion cracking in Westinghouse 1800 rpm low pressure turbine discs.
Westinghouse had made a presentation on the turbine disc cracking to electric utility executives on October 30, 1979.
Telephone discussions between the NRC staff and Westinghouse's Turbine Division on November 20, 1979 established that cracking, attributed to stress corrosion phenomena, had been found in the keyway areas of several LP turbine discs at operating plants and that inservice inspection techniques (i.e., in situ ultra-sonic examination) for crack detection have been developed and are being imple-mented in the field.
The Office of Inspection and Enforcement was also notified on November 20, 1979 that during the current overhaul of Commonwealth Edison's Zion Unit 1 LP turbine, ultrasonic examination revealed embedded cracks located on the inlet side on the disc bore area where no cracks had been previously observed.
Ultrasonic measurements indicate this disc bore cracking is of greater depth than the keyway cracks found to date.
According to Westinghouse, these bore cracks have been metallurgically examined and preliminary findings show them not to be typical of classical stress corrosion cracking observed in the keyways.
The probable cracking mechanism and impact on disc integrity is being further evaluated by Westinghouse.
A meeting was held on December 17, 1979 between the NRC staff, Westinghouse and utility representatives to discuss the disc cracking problem, repair alter-natives, turbine missile evaluation, inspection techniques and plant inspection priorities.
In response to the staffs' request, Westinghouse provided the staff an updated report on December 21, 1979 regarding the current field inspection program that included a list of nuclear power plants already inspected, recom-mended inspection schedules and pertinent information related to LP turbines where cracks have been observed.
Inspections to date have identified turbine disc cracks at Surry Unit 2, Point Beach Unit 2, Palisades, Indian Point Unit 3 and Zion Unit 1.
All units except Point Beach Unit 2 will make repairs before the plants return to power.
Point Beac wer on December 979 with a small crack in the No. 2 disc o Westinghouse indicated that the observ during 28 additional months of turbine E DUPLICATE DOCUMENT the turbine inspection results and anal Entire document previously entered into system under:
ANO of paches:
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