ML19210D957

Summary of 791026 Meeting W/Util in Bethesda,Md Re Feedwater Line Cracking at Nozzles of Steam Generators & Required Insp

ML19210D957
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	11/09/1979
From:	Schwencer A Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 7911290085
Download: ML19210D957 (7)

Text

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UNITED STATES oq e

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November 9,1979 Docket Nos. 50-295 and 50-304 LICENSEE:

COMMONWEALTH EDISCN COMPANY FACILITY:

ZION STATION, UNIT NOS.1 AND 2

SUMMARY

OF OCTOBER 26, 1979 MEETING REGARDING INSPECTIONS FOR FEEDWATER LINE CRACKING ON ZION UNIT NOS.1 AND 2 At the request of the NRC staff representatives of the licensee, CECO, met with us in Bethesda, Maryland, on October 26, 1979 to discuss recently reported NDT indications of feedwater lina cracking at the nozzles of the steam generators on Unit 1 and the licensee's plans with respect to performing the similar inspection required for Unit 2 which was still operating.

A list of meeting attendees is attached.

The purpose of the meeting was reviewed by Ed. Reeves, Project Manager, ORB #1. Reference was made to CEC 0 letter of June 19, 1979 which reported that previous radiograph: had showed no evidence of cracking. CEC 0 was asked to explain the new evidence reported to our Inspection and Enforce-ment (E) regional office on October 15, 1979 for Zion Unit No. 1.

Mr. Naughton (CECO) reviewed the situation since shutdown of Zion Unit 1 on October 6,1979 for refueling as follows:

1.

October 15 -- First CEC 0 report of indications on the first two loops inspected.

2.

October 24 -- CEC 0 letter to IE Region III reported results using examination techniques more senstive than previously used.

Examinations revealed linear indications on all four steam generator (SG) feedwater piping lines at the SG nozzle on both sides of the weld.

Piping upstream had shown no in-dications at welds on June 10-11, 1979 using the less sensitive techniques.

3.

A specimen of the piping from the nozzle area of SGl A is being removed for metalographic examination on an expedited basis.

4.

CEC 0 proposed to check Zion Unit 2 about December 2,1979.

Mr. R. Shannon, CEC 0, then discussed details of the more recent examinations and presented piping isometrics and a technical description of materials 1434 087 Oss T

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Meeting Summa *y for Zion November 9,1979 in the piping and nozzles. (The Engineering Branch of D0R will maintain a copy of sketches and other written data presented at the meeting by thelicensee).

Indications had been found on both sides of the weld in the areas shown on the attached sketch of SGi A through SGlD.

Depths of indications had been estimated at leass than 0.170 inches maximum.

However, at the meeting, CECO could not give a definitive depth estimate. Westinghouse (E. Williams) estimated 0.060-0.090 inches in depth maximum.

Zion operating history was briefly reviewed by CECO:

1.

Unit 1 started critical operations on June 19, 1973 2.

Unit 2 started critical operations on December 25,10 3.

3.

Auxiliary feedwater is maintained at a constant feed rate during hot conditions.

4.

Water hammer experience at Zion Station has been well documented.

Only Unit 2's SG 2C now has J-tubes installed. J-tube installation in the other SGs is scheduled as furture work.

Mr. W. Bamford (Westinghouse) presented a Failure Prediction Analysis which showed combined water hammer load (previous reports) plus thermal and dead weight loads. With the aid of failure prediction curves (attached) Mr.

Bamford indicated that pipe failure should not occur ever with an 80%

through-wall crack for these combined loads. A discussion of Unit 2 status of examinations was held.

CECO (Naughton) restated its position that the Unit 2 examinations should be delayed until the plant shuts down for an outage that had been scheduled to start on December 2,1979. The NRC staff considered a more expeditious check is necessary.

Following an NRC staff caucus we requested that CEC 0:

1.

Proceed to replace the affected feedwater piping '

? for all loops on Unit No.1 during the current outage.

2.

Bring Unit 2 to shutdown condition as soon as the metalographic examination and the UT evaluation is completed on the Unit 1 speciment within a week to 10 days. Also perform inspections using latest techniques and then do an analysis to determine crack size, if existent.

Data would be used from the Unit 1 inspections to evaluate the safety status of the Unit 2 piping.

This is necessary since Unit 2 has not been examined using the more sensitive examination techniques.

1434 088

Meeting Summary for Zion November 9, 1979 CECO was asked to confirm no later than October 29, 1979* a commitment to take actions as stated above.

1 R,f(fMIld$L A.Schwdncer, Chief Operating Reactors Branch #1 Division of Operating Reactors cc: See next page

• Subsequent to the meeting, discussions between DOR and CEC 0 management resulted in shutdown of Unit 2 on October 26, 1979.

1434 089

LIST OF ATTENDEES OCTOBER 26, 1979 MEETING ON ZION FEEDWATER LINE CRACKS CECO Russ Tammings, Engineering Wesley Witt, 0AD W. F. Naughton, Licensing R. E. Shannon, Zion W. Benjamin, SNED NRC/ Organization Ed. Reeves DOR, ORBI A. Schwencer DOR, ORBl*

R. A. Newmann DOR, EB T. H. Liu DOR, E3 R. W. Klecker DOR, EB William J. Collins IE, NRC*

Vince Noonan DOR, EB*

W. S. Hazelton DOR, EB*

Others Gary Ellis, Westinghouse Ed Williams, Westinghouse Ronald Street, LLL Warren Bamford, Westinghouse *

• Part-Time Attendance 1434 090

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Meeting Summary for ZIOD November 9,1979 Docket Files NRC PDR Robert J. Vollen, Esquire Local PDR 109 North Dearborn Street ORBl Reading Chicago, Illinois 60602

'NRR Reading H. Denton Cr. Cecil Lue-Hing E. Case Director of Research and Development D. Jisenhut Metropolitan Sanitary District R. Tedesco of Greater Chicago G. Zech 100 East Erie Street B. Grimes Chicago, Illinois 60611 W. Gammill L. Shao Zion-Benton Public Library District J. Miller 2600 Emmaus Avenue R. Vollmer Zion, Illinois 60099 T. J. Carter A. Schwencer M". Phillip P. Steptoe D. Ziemann Isham, Lincolr: and Beale P. Check Counselors at Law G. Lainas One First National Plaza D. Crutchfield 42nd Floor

8. Grimes Chicago, Illinois 60603 T. Ippolito R. Reid Susan N. Sekuler, Esquire V. Noonan Assistant Attorney General G. Knighton Environmental Control Division D. Brinkman 188 West Randolph Street, Suite 2315 Project Manager Chicago, Illinois 60601 OELD

. OI&E (3)

C. Parrish/P. Kreutzer ACRS (16)

NRC Participants NSIC TERA Licensee Short Service List 1434 093