ML17331A716
| ML17331A716 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 05/06/1981 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| References | |
| NUDOCS 8105130376 | |
| Download: ML17331A716 (4) | |
Text
DISTRIBUTION:
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NRC PDR Docket NosPSf-315 and 50-316 e
L PDR TERA-2 NSIC ORBIT1 Rdg SVarga SHiner NConner KParrish Q-OELD AEOD IE-3 ACRS-10 Gray File-2
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llr. John Dolan, Vice President Indiana and Nchigan Electri Post Office Box 18 Bowling Green Station New York, New York 10004 AWE "4-NA DAO'49~4' c Company 6
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Dear Hr. Dolan:
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In our August 14, 1980 letter, we concluded that the control rod guide thimble Ivear issue is resolved for the 'fl x 17 fuel asseriibl ies "designed by Hestinghouse for the D. C. Cook, Unit No. 2.
He, also, stated"that our review of this subject for facilities using fuel assemblies designed by Exxon, such as D. C. Cook, Unit tfo. 1, is contiiiuing.
He have now completed this review.
The propensity for guide thimble tube wear in Exxon reload fuel should be, to "a first approximation,'equivalent to that in Westinghouse fuel i<ere from Cycle 5 operation.
Of the --.
100 guide thimble tubes examinerI by an eddy current testing (ECT) method, only ll had detectable wear (i.e., Uiear,greater than about 3 nIils local wall thinning).
The ECT il.asurements did not reveal the aziriIuthal"distri-bution of the wear, but if tlie worsj.Yieai that was detected had been con-centrated on one side of thequfde thimble tube wall, it jould have indi-cated that a mirtiiqum of 23K of the iia11 thickness remained.
He conclude that (a) the degree ofprear measured by Exxon is acceptable, (b) the degree of wear in the Exxon'fuel is 'similar to tliat in ltestinghouse fuel, which we have found acceptable,,and (c) therefore the issue of'guide thimble wear in D. C.
Cook Nuclear P1ant, Unit No.
1 has been adequately reso ve.
Sincerely, 826S l,e 0 911>
Original signed baal Steven A. Varga, Chief Operating-Reactors'ranch rl'1 OFFICE/
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Docket Nos.
50-315 and 50-316 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 May 6, 1981 Mr. John Dolan, Vice President Indiana and Michigan Electric Company Post Office Box 18 Bowling Green Station New York, New York 10004
Dear Mr. Dolan:
In our August '14,.1980 letter, we concluded that'the control rod guide
'himble wear issue is resolved for the 17 x 17 fuel assemblies designed by Westinghouse for the D. C. Cook, Unit No. 2.
We, also, stated that our review of this subject for facilities u'sing fuel assemblies designed by Exxon, such as D.
C. Cook, Unit No. 1, is continuing.
We have now completed this review.
The propensity for guide thimble tube wear in Exxon reload fuel should be,, to a first approximation, equivalent to that in Westinghouse fuel in the same plant.
Examinations of Exxon fuel that was discharged from H. B. Robinson, Unit No. 2, as reported by Exxon letter dated February 25, 1980, revealed no through-wall wear nor major differences in the wear from that wear which was measur'ed on Westinghouse fuel that was discharged from Pt.
Beach, Units Nos.
1 and 2.
The Exxon examinations were performed on 5 fuel assemblies that had been under control rod banks for one cycle of reactor operation.
One assembly was from Cycle 4 and four assemblies were from Cycle 5 operation.
Of the 100 guide thimble tubes examined by an eddy current testing (ECT) method, only ll had detectable wear (i.e., wear greater than. about 3 mils local wall thinning).. The ECT measurements did not reveal the azimuthal distri-bution of the wear, but if the worst wear that was detected had been con-centrated on one side of the guide thimble tube wall, it would have indi-cated that a minimum of 23K of the wall thickness remained.
4 We conclude that (a) the degree of wear measured by Exxon is acceptable, (b) the degree of wear in the Exxon fuel is similar to that in Westinghouse fuel, which we have found acceptable, and (c) therefore the issue of guide thimble wear in D.
C.
Cook Nuclear Plant, Unit No.
1 has been adequately res ol ved.
- ncerely, cc:
See next page teven A. Varga( hief Operating React rs Branch Pl Di vision of'icen ng
'.!v i~he Dolan
- ndiana and M"
- chigan Electric Co~any cc:
Mr. Robert M. Jurgensen Chief Nuclear Engineer American Electric Power Service Corporation 2 Broadway Nev York, New York 10004 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.l.
ti'ashinqton, D.
C.
20036 Maude Preston Palenske Memorial Library 500 Market Street St.
- Joseph, Michigan 49085 Mr. 0- Shaller, Plan+ Manager Donald C.
Cook Nuclear'Plant
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Box 458 Bridgman, Michigan 49106 U. S. Nuclear Regulatory Cormission Pesident Inspec ors 0 fice 770 Red Arrow Highway Stevensvi lie, Michioan 49127 liilliam J.,Scanlon, Esquire ZG34 Pauline Boulevard Ann Arbor, Michigan 48103