ML19290B702

Interim Deficiency Rept Re Broken Reactor Vessel Anchor Stud.Vessel Support Skirt Flange Anchor Bolt Broke.Testing for Cause of Break Will Be Completed by Mid Jan 1980, W/Results Available by Mid Feb 1980

ML19290B702
Person / Time
Site:	Midland
Issue date:	12/14/1979
From:	Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
References
HOWE-311-79, NUDOCS 7912130544
Download: ML19290B702 (2)

Text

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{Q gg Stephen H. Howell Senior Vice President General offices: 1945 West Pernall Road, Jackson, Michigan 49201 e (517) 788-0453 December Ib, 1979 Hove-311-79 Mr J G Keppler, Regional Director Office of Inspection and Enforcement US Naclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND NUCLEAR PLANT UNIT NO 1, DOCKET NO 50-329 UNIT NO 2, DOCKET No 50-330 UNIT NO 1, REACTOR VESSEL BROKEN ANCHOR BOLT

Reference:

Letter SHHowell to JGKeppler; Midland Nuclear Plant; Unit No 1, Docket No 50-329; Unit No 2, Docket No 50-330; Unit No 1 Reactor Vessel Broken Anchor Bolt; Hove-267-79; dated October 12, 1979 This letter, as was the referenced letter, is an interim 50.55(e) report concerning the broken anchor bolt in the Unit 1 reactor vessel support skirt flange. The attachment to this letter provides a status of the actions being taken to resolve this condition.

Another r'eport, either interim or final, vill be sent on or before March 3, 1980.

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M WRB/1r

Attachment:

Broken Reactor Vessel Anchor Bolt in Unit 1 Status Report, dated December 5, 1979 CC: Director of Office of Inspection & Enforcement Att: Mr Victor Stello, USNRC (15)

Director, Office of Management Information and Program Control, USNRC (1) 1553 230 vg12130 5 tit

Date: 12/5/79

SUBJECT:

BROKEN REACTOR VESSEL ANCHOR STUD IN UNIT 1 STATUS REPORT Introduction This report su=marizes the additional action taken to date to determine the failure mechanism of the subject anchor stud and corrects the identity of the procurement source for the stud that failed.

History of Failed Stud The anchor stud that failed was identified as stud number 35, and was in-correctly located on Figure 1 of the previous status report. More correctly, the stud has no specific numerical identifier, the cited number 35 being only the Babcock and Wilcox tensioning sequence identifier. The revised Figure 1 attached clarifies the identified position of the stud.

This stud was purchased from Mississippi Valley Structural Steel Company who procured the material from Southern Bolt and Fastener Corporation. The material originated from Bethlehem Steel, was heat treated by J W Rex Company of Lansdale, Pennsylvania, for Southern Bolt and Fastener Corporation, and completed and shipped by Southern Bolt and Fastener Corporation directly to Bechtel.

Investigation Plan Bechtel, as agents for Consumers Power Company, has entered into a Technical Services Agreement with Teledyne Engineering Services of Waltham, Massachusetts, for testing and consultant services to determine the cause of the failure. The program for planned testing remains as described in the previous status report.

The testing co=menced on November 15, 1979 with Non-Destructive Examination.

The expected completion date for the planned series of tests is mid-January, 1980, with recultc available by mid-February,1980. After the results are received from Teledyne and reviewed, a course of action to correct this deficiency will be determined. .

Safety Innlications Based on preliminary analysis, it is judged that the failure of a single anchor stud does not represent an impediment to the safety-related support requirements for the reactor vessel. Overall safety implications will be further evaluated upon receipt of test data.

_Reportability This condition remains in the potehtially reportable category pending the results of the currently in prcgress testing program. -

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