ML19290E714
| ML19290E714 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/25/1980 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Ferguson J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8003140434 | |
| Download: ML19290E714 (3) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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WASHINGTON. D. C. 20555 g ~7j!
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February 25, 1980 Docket No.
50-338 Mr. J. H. Ferguson Executive Vice President - Power Virginia Electric and Power Comany Post Office Box 26666 Richmond, Virginia 23261
Dear Mr. Ferguson:
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 provided by Westinghouse and recent indications from turbine disc inspections now undersay at Arkansas 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 requested 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 your license to operate North Anna, Unit No. I 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.
130031 40
Mr. J. H. Ferguson February 25, 1980 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.
Sincerely, I
l s
l Darrell G.
sen ut, Acting L'irector Division of perating Reactors Enclosu res:
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. J. H. Ferguson Virginia Electric and Power Company February 25, 1980 cc: Mr. Anthony Gambardella Mr. Michael S. Kidd Office of the Attorney General U. S. Nuclear Regulatory Commission 11 South 12th Street - Room 308 P. O. Box 128 Richmond, Virginia 23219 Spotsylvania, Virginia 22553 Richard M. Foster, Esquire Director, Technical Assessment Division 1230 A Pearl Street Office of Radiation Programs (AW-459)
Denver, Colorado 80203 U. S. Environmental Protection Agency Crystal Mall #2 Michael W. Maupin, Esquire Arlington, Virginia 20460 Hunton, Williacs, Gay and Gibson P. O. Box 1535 U. S. Environmental Protection Agency Richmond, Virginia 23212 Region III Office ATTN: EIS C0ORDINATOR Mrs. June Allen Curtis Building 6th and Walnut Streets 412 Owens Drive Huntsville, Alabama 35801 Philadelphia, Pennsylvania 19106 Mr. Janes Torson Alderman Library 501 Leroy Manuscripts Department Socorro, New Mexico 87801 University of Virginia Charlottesville, Virginia 22901 Mrs. Margaret Dietrich Route 2, Box 568 Mr. Edward Kube Gordonsville, Virginia 22042 Boaro of Supervisors Louisa County Courthouse Ellyn R. Weiss, Esquire P. O. Box 27 Sheldon, Harmon, Roisman and Weiss Louisa, Virginia 23093 1725 I Street, N.W., Suite 506 Washington, D. C.
20006 Mr. J. B. J ackson, J r.
Commonwealth of Virginia Mr. James C. Dunstan Council on the Environment State Corporation Commission 903 Ninth Street Office Building Commonwealth of Virginia Richmond, Virginia 23129 Blandon Building Richmond, Virginia 23209 Mr. Paul W. Purdom Environmental Studies Institute Mr. A. D. J ohnson, Chai rman Drexel University Board of Supervisors of Louisa County 32nd and Chestnut Streets Trevillians, Virginia 23170 Philadelphia, Pennsylvania 19104 e
Mr. J. H. Ferguson Virginia Electric and Power Company Februa ry 25, 1980 cc:
Mr. W. R. Cartwright Station Manager P. O. Box 402 Mineral, Vii ginia 23117 Alan S. Rosenthal Esonire Atomic Safety and Lie ing Appeal Board U. S. Nuclear Regulats.y Commission Washington, D. C.
20555 Michael C. Farrar, Esquire Atomic Safety and Licensing Appeal Board C. S. Nuclear Regulatory Commission Washington, D. C.
20555 Dr. John H. Buck Atomic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Atomic Safety and Licensing Board Panel V. S. Nuclear Regulato " Commission Washington, D. C.
20555
.(Ic.ure 1 UNITED STATES ISINS NO.:
G870 NUCLEAR REGULA10RY CORMISSION Accession No.:
OFFICE OF INSPEClION AND ENFORCEMENT 7910250525 UASHIN'iTON, 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 l
50.55e and/or 10 CFR 21 Regulations concerning reportability of recently discovered i
stress corrosion cracking in Westinghouse 1800 rpm low prassure turbine discs.
Vestinghouse had c.ade a presentation on the turbine disc cracking to electric l
utility executives on October 30, 1979.
i Telephone discussions between the NRC staff and Westinghouse's Turbine Division on Novecber 20, 1979 astablished that cracking, attributed to stress corrosion
,' e n c - na, h d Lnn fc
,.,d in the Leymy areas of several LP turbine discs at cperatii.g plcnts md that inservice inspection techniques (i.e., in situ ultra-sonic exa.iuation) far crack detectica have been develcped and are being imple-T.ented in the field.
The Of fice of Inspection and Enforcement was also notified c n Nc'.. bar 20, l'379 that during the curront overhaul of Corconw alth Edison's Zion Unit 1 LP t uibine, ultraronic ex:T.ination revealed embedded cracks located on the inlet side on the disc Lore area w'.cre no cracks had been previously cSsaved.
Ultrascnic r..en ure.aents indicate this disc bore cracking is of greater depth t'.an the keysay cracks found to date.
According to Westinghouse, these bare cr.ecks hw e been metallurgically examined and preliminary findings show them not to be typical of classical stress corrosion cracking observed in the keyways.
The prob-ble cracking t >chanim and impact on disc integrity is being further evaluated by Westinghouse.
A meeting was held on December 17, 1979 betwaen the NRC staf f, Westinghouse and utility representatives to discuss the disc cracking problem, repair alter-1 r.atives, turbirie aissile evaluation, inspection techniques and plant inspection priorities.
In respanse to the staf fs' request, Westinghouse provided the staf f 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 crach have been observed.
Inspections to date have identified turbine disc cracks at Surry Unit 2, Point Beach Unit 2, Palisades, Indian Point Unit 3
.ld Zicn Unit 1.
All units except Point Scach Unit 2 will rike repairs before the plants return to power.
Point ~
with a small crack in the No. 2 di Westinghouse indicated that the ob during 23 additional conths of tur DUPLICATE DOCUMENT the turbine inspection results and Entire document previously entered into system under:
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