ML19290E752
| ML19290E752 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 02/25/1980 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Clayton F ALABAMA POWER CO. |
| References | |
| NUDOCS 8003140474 | |
| Download: ML19290E752 (3) | |
Text
l
~
I C 0 J-T pa acog g
k UNITED STATES y
3.,q g
NUCLEAR REGa ATORY COMMISSION E
WA$HINGTON, D. C. 20555 a
%,...../
February 25, 1980 Docket No.
50-348 Mr. F. L. Clayton, J r.
Senior Vice President Alabama Power Company Post Office Box 2641 Birmingham, Alabama 35291
Dear Mr. Clayton:
On December 28, 1979 the NRC Office of Inspection and Enforcement issued Information Notice No. 79-37 that presented information available to the staff related to the discovery of cracks in the keyway and bore sections of Westinghouse 1800 rpm low pressure turbines. A copy of this Information Notice with errata sheet is enclosed.
Westinghouse notified utility users of this potential problem on October 30, 1979 and was requested by the staff to present a similar briefing in Bethesda, Maryland on December 17, 1979. You were contacted on December 14, 1979 and invited to send representatives to the staff briefing and also were requested to advise the staff of the actions being taken in regard to this potential problem at your operating nuclear power plant.
Westinghouse was later requested to meet again with the staff and licensee-users on January 8,1980 to supplement the information provided in the earlier meeting and in interim correspondence with the staff.
On the basis of information provideo by Westinghouse and recent indications from turbine disc inspections now underway at ArFansas Nuclear One Unit
- 1. Beaver Valley Unit 1 and Indian Point Unit 2, it is evident that the probability of crack formation in these turbine discs is significantly greater than previously assumed by the vendor.
In light of this information and the actions being taken by the licensee-users, we consider this warrants your prompt full UT inspection of LP rotor discs, especially the keyways and bore areas, and documentation to the NRC of your justification for continued operation until such inspections are made and all defects thus identified are corrected. Therefore, in accordance with 10 CFR 50.54(f), you are r-equested to provide within 20 days of the date of this letter, or in any event prior to restart if your unit is not operating, written statements, signed under oath or affirmation, which will enable the staff to determine whether or not year license to operate Joseph Farley Nuclear Plant, Unit 1 should be modified, suspended, or revoked. As part of your statement, you should provide and address the safety significance of the information requested in Enclosure 2 to this letter.
800314of,7f
i Mr. F. L. Clayton, Jr. Februa ry 25, 1930 Because of the general nature of the information sought in Enclosure 2 we are transmitting a copy of this enclosure to Westinghouse by separate letter. As discussed in the December 17, 1979 meeting we urge you to address the generic aspects of this problem and to coordinate your responses through an owner's group.
11ncerely,
(,
arre ' G.' E hu, ct ng Director Division of erating Reactors
Enclosures:
1.
IE Information Notice No. 79-37 With Errata Sheet 2.
Request for Information Related to Turbine Disc Cracks - 20 Day Response cc: w/ enclosures See next page
Mr. F. L. Clayton, J r.
Alabama Power Cocpany February 25, 1980 cc: Alan R. Barton Executive Vice President Alabama Power Company Post Office Box 2641 Birmingham, Alabama 35291 Ruble A. Thomas, Vice President Southern Cocpany Services, Inc.
Post Office Box 2625 Birmingham, Alabama 35202 George F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbrid,ge 1800 h Street, N.W.
Washington, D. C.
20036 John Bingham, Esquire Balch, Bingham, Baker, Hawthorne, Williams and Ward 60C North 18th Street Bi rmi ngFam, Alabama 35202 Edward H. Keiler, Esquire Keiler and Buckley 9047 Jefferson Highway River Ridge, Louisiana 70123 George S. Houston Memorial Library 212 W. Burdeshaw Street Dothan, Alabama 36303
..o:gre 1 Poli t 0 $1M ES ISINS NO.: 6870 lwCl GR
.1i m A.Gr.f COP:il5S10N Accession No.:
01 F1CE OF DML)!CN /sND ENf0RCf.l ENT 7910250525 UY MIfnTnN, D.C.
20555 Deccher 28, 1979 IE Information Notice No. 79-37 G M KING IN LOW PRESSURE TURBINE DISCS C-3cription of C:rcumstances:
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 50.55c and/or 10 CFR 21 Regulations concerning reportability of recently discovered stress corrosion crackir.g in Vestinghouse 1800 rpm low pressure turbine discs.
Vestinghouse had cade a presentation on the turbine disc cracking to electric utility executives on October 30, 1979.
Telepbcne discussions between the NRC st.aff and Westinghouse's Turbine Division on Nov.>:bar 20, 1979 established that cracking, attributed to stress corrosion
- henr'.n, ' d ', n fcend in the !. pay arcas of several LP turbine discs at cperati.,g,1.
- M s and that i.itervice i.apactica techniques (i.e., in situ ultra-sonic m.in:t!un) for crack d tection have Lecn developed and are being imple-
.:-nted in tha field.
The Of fice of Inspestion and Enforcement was also notified on Nv.
.ber F0, 1979 th.3t during the current cverhaul of Co. mon.<ealth Edison's Zicn Unit 1 LP turbine, ultre.scnic ex c.ination i cvcaled embedded cracks located on the in1.'t s Ma :n the disc bore area w ire no cr'ds had been previousl.,
obser.ad.
Ultre.-enic ma nurcments indir..e this disc bore cracking is of greater depth than the kep,ay cracks found to date.
According to Westinghouse, these bore cracks have been metallurgically examined and preliminary findings show them not to Le typical of classical stress corrosion cracking observed in toe kepeays.
The pi c' 'ble crad ing vechanism and irp,ct on disc integrity is being further eval u ted by estinghouse.
A meeting was held on Dece-ber 17, 1979 between the NRC staff, Westinghouse and utility representatives to discuss the disc cracking problem, repair alter-natives, turbine cirsile evaluation, inspection techniques and plant inspection priuriti's.
In respase to the staf fs' request, Vestinghouse previded the staf f an ydated re, port 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'Seach Unit 2, Palisades, Indian Point Unit 3 cod Zion Unit 1.
All units except Point Seach Unit 2 will make repairs before the plants return to pc-er.
Point Beach returned to power on Dece:Ser 23 979 with a small crack in the No. 2 d Vestinghouse indicated that the et s
during 28 additional conths of tui DUPLICATE DOCUMENT the turbine insp'ction results an Entire document previously entered into system under:
ANO oh pages:
h No.
~
_