ML19257C161
| ML19257C161 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle  |
| Issue date: | 12/28/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | John Miller GEORGIA POWER CO. |
| References | |
| NUDOCS 8001250109 | |
| Download: ML19257C161 (2) | |
Text
4
'o UNITED STATES 8'3p NUCLEAR REGULATORY COMMISSION s.A AI E REGION 11 3
b[
o, 101 MARIETTA ST., N.W., SUITE 3100 o
ATLANTA, G EORGIA 30303 DEC 2E: ht)
In Reply Refer To:
RII:JPO 50-321-50-166
[ 424 50-4
?
3 Georgic. Power Company Attn:
J. H. Miller, Jr.
Executive Vice President 270 Peachtree Street, N.W.
Atlanta, Georgia 30303 Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time.
If NRC evaluations so indicate, further licensee actions may be requested or required.
If you have questions regarding this matter, please contact the Director ci the appropriate hTC Regional Office.
Sincerely,
,[
James P. O'Re N y Director
Enclosures:
1.
IE Information Notice No. 79-37 2.
List of Recently Issued IE Information Notices 182{ 017 8001 5 0 t () ']
DEC 28197s Georgia Power Company cc w/ encl:
M. Hanry, Plant Manager Post Office Box 442 Baxley, Georgia 31513 C. E. Belflower Site QA Supervisor Post Office Box 442 Baxley, Georgia 31513 K. M. Gillespie Construction Project Manager Post Office Box 282 Waynesboro, Georgia 30830 E. D. Groover QA Site Supervisor Post Office Box 282 Waynesboro, Georgia 30830 W. A. Widner, General Manager Nuclear Generation Georgia Power Company Post Office Box 4545 Atlanta, Georgia 30303 I
182f018 i
1 1
r
UNITED STATES 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 cf 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 ao cracks had been previously obs e rved. Ultrasonic measurements indicate this 1sc bore cracking is of greater depth taan 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 *:rpaction 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 o'
and Zion Unit 1.
All units except Poin the plants r-turn to power.
Point Beac with a small crack in the No. 2 disc of DUPLICATE DOCUFENT Westinghouse indicated that the observe during 28 additional months of turbine Entire document previously the turbine inspection results and anal entered into s stem unde :
ANO N o.
of pages:
jg}
gj