ML20246C276

Forwards Request for Addl Info Re Containment Tendon Wire Strength & Tendon Inservice Insp Issue in Order to Complete Review,For Response within 45 Days from Receipt of Ltr

ML20246C276
Person / Time
Site:	LaSalle
Issue date:	05/03/1989
From:	Shemanski P Office of Nuclear Reactor Regulation
To:	Kovach T COMMONWEALTH EDISON CO.
References
TAC-71396, TAC-71397, NUDOCS 8905090316
Download: ML20246C276 (5)

Text

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.',o UNITED STATES g

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g NUCLEAR REGULATORY COMMISSION 7,

j WASHINGTON, D, C. 20555 t

p flay 3,1989 Docket Nos.:

50-373 and 50-374 Mr. Thomas J. Kovach Nuclear Licensing Manager Connonwealth Edison Company P. O. Box 767 Chicago, Illinois 60690

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - CONTAINf1ENT TENDON WIRE STRENGTH AND TENDON INSERVICE INSPECTIONS FOR LASALLE UNITS 1 AND 2 TAC NOS. 71396 AND 71397 Based on the February 15, 1989 meeting with Commonwealth Edison Company, the staff finds that additional information is required in the evaluation of containment tencon wire strength and tencon inservice inspection issue in order to complete the review.

Enclosed please find the additional information required.

Your response is requested 45 days from receipt of this letter.

If you should have any questions, please contact Paul Shemanski, Project Manager,at(301)492-3101.

The reporting and/or recordkeeping requirements contained in this letter affect fewer then 10 respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, GJLc.ru Paul C. Shemanski, Project Manager Project Directorate III-2 Division of Reactor Projects III, IV, V, and Special Projects

Enclosure:

As stated cc: See next page f I 1

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fiay - 3, 1989.

Docket Nos.: 50-373 and 50-374 Mr. Thomas'J. Kovach Nuclear Licensing Manager Commonwealth Edison Company.

P. O. Box-767 Ch'icago, Illinois 60690

SUBJECT:

REQUEST FOR ADDITIONAL-INFORMATION - CONTAINMENT TENDON WIRE

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STRENGTH AND TENDON. INSERVICE INSPECTIONS FOR LASALLE UNITS 1 AND.2 i

TAC NOS.l71396 AND 71397 I

Based on the February 15, 1989 meeting with Coninonwealth Edison Company, the

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staff finds that additional information 1s required in the evaluation of-containment. tendon wire strength and tendon inservice inspection-. issue in j

order to complete.the review. Enclosed please find the additional information required. Your response is requested 45 days from receipt of this.

1 letter.,

If you should have any questions, please contact Paul Shemanski, Project Manager, at (301) 492-3101.

The reporting and/or recordkeeping requirements-contained in this letter j

affect fewer than 10 respondents; therefore, OMB clearance is.not required under P.L.96-511.

.Th.

l Paul C. Shemanski, Project Manager' Project Directorate III-2 Division of Reactor Projects III, IV, V, and Special Projects

Enclosure:

As stated 1

cc: See next page J

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Mr. Thomas J. Kovach LaSalle County Nuclear Power Station Commonwealth Edison Company '

Units 1 & 2 l

CC:

1 Phillip P. Steptoe, Esquire John W. McCaffrey Sidley and Austin Chief, Public Utilities Division One First National Plaza SOIC Chicago, Illinois 60603 100. West Randolph Street Chicago, Illinois 60601 Assistant Attorney General 100 West Randolph Street l

Suite 12 l

Chicago, Illinois 60601 l

Resident Inspector /LaSalle, NPS U.S. Nuclear Regulatory Comission Rural Route No. 1 P. O. Box 224 i

Marseilles, Illinois 61341 Chairman LaSalle County Board of Supervisors LaSalle County Courthouse Ottawa, Illinois 61350 Attorney General j

500 South 2nd Street i

Springfield, Illinois 62701 Chairman Illinois Commerce Commission Leland Building 527 East Capitol Avenue Springfield, Illinois 62706 Mr. Michael C. Parker, Chief Division of Engineering Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 Regiorial Administrator, Region III U. S. Nuclear Regulatory Comission 799 Roosevelt Road, Bldg. f4 Glen Ellyn, Illinois 60137 l

7 ENCLOSURE EVALUATION OF CONTAINMENT TENDON WIRE STRENGTH-AND TENDON INSERVICE INSPECTIONS, AND REQUEST 4

FOR ADDITIONAL INFORMATION. LA5ALLE 1 & 2

References:

1.

Special Report Attached to the-Commonwealth Edision 1

Letter to Mr. Bert A. Davis (Region III) Dated I

September 28, 1988 l

i 2.

Request for Additional Information from Paul-Shemanski (PM) to Mr. Henry E. Bliss (Commonwealth ED.) Dated December 12, 1988 1

BACKGROUND:

During the 5th year inspection of Unit 2 and the 10th year

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inspection of Unit I, it was found that two of the 12 wire samples tested had their ultimate strengths slightly below theguaranteedultimatetensilestrengthofwires'(Ref.1).

The staff had determined that though these results are in violation of the technical specification requirement, such.

incidence is within the tolerance level for wire strength and their extrapolated consequence would not affect the capacity of the containment to resist the postulated design accident loads. However, the staff asked (Ref. 2) the licensee to provide evidence to demonstrate that the incidence is not a systematic pattern of degradation. During the review of the reference the staff also noticed certain irregularities in the behavior of comon tendons. To discuss the two concerns, Commonwealth Edison requested a meeting with the staff on.

February 15, 1989. The actions identified below resulted from staff review of the additional information provided by the licensee during the meeting.

1.

No need to detension additional tendons before the next scheduled inspections.

2.

Formally submit the following (as discussed during the meeting):

a.

Wire strength variations and comparative chart l

demonstrating that the type of variation indicated by concern 2(Ref.2))isattributabletothenormal' variation inwire(heat / coil strength from one end to the other.

b.

Reexamine comon tendon behavior. Allow 2% tolerance in the measured tendon forces and show that the irregularity indicated by concern 1 (Ref. 2) is attributable.to the 2% error in the measurement of tendon forces.

3.

During the meeting it was indicated that the sustained temperatures on both sides of the containment wall are higher than the ones considered in the design.

Investigate the effects of sustained high temperatures around'the containment wall on the long-term prestressing forces, grease and on the concrete around the hot penetrations.

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4.

During the next scheduled inspection of both units, in addition to the routine inspection, detension two additional tendons (one from each unit) adjacent to the ones showing low wire strengths and test the wire samples together with the wire samples from the routine inspections.

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