ML20054E430

Final Deficiency Rept Re Main Steam Valve Room a Pipe Anchor Support Loads,Initially Reported on 820723.Concrete Stiffening Walls Designed & Released to Increase Capacity of R-line Wall in Area of Main Steam Pipe Anchors

ML20054E430
Person / Time
Site:	Bellefonte
Issue date:	06/03/1982
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8206110202
Download: ML20054E430 (2)

Text

t a

f TENNESSEE VAhtEY

.- s t o n r< c.gm f, AUTHORITY

cHgf4gogGLA. TENNESSEE 374ot 400 Chestnut Street Tower II I AB 2

<37 p!.O June 3, 1982 BLRD-50-438/81-50 BLRD-50-439/81-52 U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - MAIN STEAM VALVE ROOM A PIPE ANCHOR SUPPORT LOADS - BLRD-50-438/81-50, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on July 23, 1981 in accordance with 10 CFR 50.55(e) as NCR BLN BLP 8120. This was followed by our interim reports dated August 18, October 6, and November 13, 1981 and February 9, March 11, and April 22, 1982. Enclosed is our final report.

If you have any questions concerning this matter, please get in touch with R. H. Shsll at FTS 858-2688.

Very truly yours, TENNESSEE VALLEY AUTHORITY D SW L. M. Mills, Manager Nuclear Licensing Enclosure cc: Mr. Richard C. DeYoung, Director (Enclosure)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 kS O

An Equal Opportunity Employer

h e

ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 MAIN STEAM VALVE ROOM A PIPE ANCHOR SUPPORT LOADS NCR BLN BLP 8120 BLRD-50-438/81-50, BLRD-50-439/81-52 10 CFR 50.55(e)

FINAL REPORT Description of Deficiency Two main steam pipe anchors and one feedwater pipe anchor (6-way restraints) per unit are attached to the R-line wall in the A main steam valve rooms. The original design of the R-line wall and roof slab was accomplished utilizing preliminary loads and preliminary anchor design concepts. The anchor design was completed and the actual anchor embedment loads determined. Although the actual loads were significantly higher than the preliminary design loads, the R-line wall and roof slabs were not reevaluated analytically but were reviewed subjectively and said to be acceptable by inspection which does not provide adequate design review.

Deficiency No. 5 of audit M81-13 identified this nonconformance as being part of a generic problem of inadequate design review. .

Safety Implications -

If the R-line wall and roof slabs lacked sufficient capacity to withstand the applied anchor embedment loads, the main steam line and/or main feedwater line anchors could fail. Should this happen, the main steam isolation valves could be damaged, resulting in a steam generator blowdown; or the main feedwater isolation valve could be damaged, resulting in an overcooling condition in the steam generator. Such multiple failures, if they occurred, would degrade the safety of operations of the plant.

Corrective Action Concrete stiffening walls have -been designed and released to increase the capacity of the R-line wall in the vicinity of the unit 1 and unit 2 center main steam pipe anchors. These stiffening walls, in conjunction with the existing R-line wall and remaining reinforcing, provide sufficient capacity to resist the applied anchor loads. The walls at the corner main steam and feedwater anchors were determined to be acceptable as is. The adjacent walls and slabs, acting together with the existing R-line wall and remaining reinforcing, provide adequate capacity to resist the applied anchor loads at the corners. The modifications will be completea by September 1, 1983 for unit 1 and September 1, 1984 for unit 2.

Actions to prevent the recurrence of design review deficiencies of this type will be addressed in the final report on audit M81-13, Deficiency No. 5.

. .- - .- . - - _- . . .- . . .-