ML19345G577

Interim Deficiency Rept 8 Re Reactor Vessel Broken Anchor Bolts,Initially Reported on 791012.Encl Repts Establish That Root Cause for Excessive Hardness Was Tempering of Some Studs at Lower than Min Temp.Addl Rept to Be Sent by 810724

ML19345G577
Person / Time
Site:	Midland
Issue date:	03/31/1981
From:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19345G578	List: ML19345G577 ML19345G580 ML19345G581
References
10CFR-050.55E, 10CFR-50.55E, 11524, NUDOCS 8104070546
Download: ML19345G577 (2)

Text

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Consumers power James W Cook Vice Pressdent - Projects. Engineenng and Constructson oeneral Orf 6ces: 1945 West Parnell Road, Jackson, MI 49201 * (517) 788 0453 79 88

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Maren 31, 1981 II.

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Mr J G Keppler, Regional Director J

Office of Inspection c.nd Enforcement US Nuclear Regulatory Commission y

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Region III 6

799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND PROJECT -

DOCKET NCS 50-329, 50-330 UNIT NO 1 - REACTOR VESSEL BROKE *i ANCHOR BOLT FILE:

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73*10*01, 02111(S), 21114(E) SERIAL:

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References:

(1) CPCo letters to J G Keppler, Same

Subject:

(a) Hove-267-79, dated October 12, 1979 (b) Hove-311-79, dated December 14, 1979 (c) Hove-51-80, dated March 3,1980 (d) Hove-80-80, dated April 30, 1980 (e) Serial 8971, dated May 16, 1980 (f) Serial 8809, dated August 1,1980 (g) Serial 9787, dated December 10, 1980

-(2) J G Keppler letter to S H Howell, D >cket No 50-329 and 50-330, dated August 18, 1980 (3) R L Tedesco letter to J W Cook, Docket No 50-329 and 50-330, dated March 6 1981 References (1) (a) through (g) were interim 50.55(e) reports, as is this letter, concerning the broken anchor bolts in the Unit No 1 reactor vessel support skirt. Enclosures 1 and 2 are Teledyne Engineering Services (TES) reports on the " Continued. Investigation of the Failure of Midland Unit 1 REV Anchor Studs".

These enclosures represent the completion of an investigation

. into the " root caute" for the excessive hardness, which was described in previously submitted TES reports. These reports establish that the " root cause" for the excessive hardness was tempering of some of the studs e.t a temperature which was lover than the minimum specified by the applicable ASTM specification.

This " root cause" does not affect the allovable preload and accident leadings recommended by TES in their. (previously submitted) report #TR-3887-2, Rev 1.

These allowable preload and accident loadings continue to form a portien of the basis for the modified reactor. vessel support system. While it is possible 8104070546

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1. 3 Serial ll52L that control of temp- ;ng temperat~ re may have been inadequate for ot:.'" bolting at the Midland Flant, it is anticip tted that those conditions will te revealed in the work which is being perforcea under cctritments relative to the 50.55(e) on low clloy, quenched and tempered bolts in safety-related systers, lh" and larger in diameter (3echtel MCAR #L55), CFCo 50 55(e) Report no 60-09. provides the status of actions taken to resolve this condition.

Reference (2) specified a condition that there be a construction hold on the proposed upper lateral support modification until approval was obtained fre:

URR.

Reference (3) gave NRR's approval to begin the proposed ecnstructicn modifications.

In a March 11, 1981 telephcne eenversation between J L Weed (CFCo) and D 3cyd (USNRC Region III), it was determined that the ecnstruction hold could be lifted as allowed in Reference (3).

Another report, either interin er final, vill be sent en or before July 2L, 1981.

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Enclosures:

1.

TES Report No TR L599-1, "Centinued Investigation of the Failure of Midland Unit 1 RFV Anchor Studs - Eata Repcrt,"

dated February 11, 1981 2.

TES Report No TR L599-2, " Continued Investigatica of the Failure of Midland Unit 1 RF7 Anchor Studs - Analysis Report," dated February 11, 1981 3.

MCAR-37, Interin Report #5, March 6,1951

" Broken Reactor Vessel Anchor Stud in Unit 1" CC:

Director, Cffice of Inspection & Enforcement Att Mr Victor Stello, USNRC (36)

Directcr, Office of Management Information & Progra Control, USNRC (1)

RJCeck, USURC Resident Inspector Midland Nuclear Plant (1)

C3echhoefer, ASL3 FJKelly, Esq, Attorney Geneal GALinenberger, ASL3 SRFreeran, Esq, Asst Attcrney General FFCowan, AS13 GTTaylor, Esq, Asst Atterney General AS&L Appeal Panel WEMarshall MMCherry, Esq GJMerritt, Esq, TN &J MSinclair CRStephens, USURC WEFatcn, Esq, USHRC

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