ML20063P440

Fourth Interim Deficiency Rept Nonconservative FSAR Analysis for Loss of Normal Feedwater Event.Initially Reported on 810316.ASME Code Limits Will Be Exceeded Following Loss of Feedwater.Also Reported Per Part 21

ML20063P440
Person / Time
Site:	Bellefonte
Issue date:	10/05/1982
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-82 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8210130407
Download: ML20063P440 (2)

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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374o1 400 Chestnut Street Tower II October 5, 1982 BLRD-50-438/81-24 BLRD-50-439/81-26 U.S. Nuclear Regulatory Conmission  % Uc Region II o r 9^

. Attn: Mr. James P. O'Reilly, Regional Administrator c3

" l' 3 101 Marietta Street, Suite 3100 c'

Qo Atlanta, Georgia 30303 Eo oT

Dear Mr. O'Reilly:

3 rd' c:a oa BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - ANALYSIS FOR LOSS OF FEEDWATER ,

EVENT - BLRD-50-438/81-24, BLRD-50-439/81 FOURTH INTERIM REPORT $ 6

The subject deficiency was initially reported to NR$0IE Inspector .

J. Crlenjak on March 16, 1981 in accordance with 10 CFR 50 55(e) as NCR BLN NEB 8102. Thh was followed by our interim reports dated April 13 and November 16, 1981 and March 3, 1982. Enclosed is our fourth interim report. We expect to submit our next report by February 23, 1983 We consider 10 CFR Part 21 applicable to this deficiency.

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

Very truly yours, TENNESSEE VALLEY AUTHORITY 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, D.C. 20555 Mr. James McFarland (Enclosure)

Senior Project Manager Babcock & Wilcox Company P.O. Box 1260 l Lynchburg, Virginia 24505 l

GF14CIALC%!f a

P !!8&ogan l

PDR An Equal Opportunity Employer

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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 ANALYSIS FOR LOSS OF FEEDWATER EVENT NCR BLN NEB 8102

• BLRD-50-438/81-24, BLRD-50-439/81-26 1 10 CFR 50.55(e)

FOURTH INTERIM REPORT,

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Description of Condition '

The Bellefonte Final Safety Analysis Report (FSAR) analysis for the loss of normal feedwater event (section 15.2 7) may not be conservative. The Bellefonte FSAR analysis predicts that the ASME Section III Code limits for

overpressurization of the Reactor Coolant System will not be exceeded following a loss of normal feedwater. The Babcock and Wilcox (B&W) ~

Company has performed a more recent analysis for the Washington Public Power Supply System (WPPSS) which predicts that the ASME Code limits for j overpressurization will be exceeded following a loss of feedwater (LOFW).

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! A B&W representative stated, during a March 12, 1981 meeting of the B&W

,' Nonoperating Owners Group, that B&W analysts had reason to suspect a nonconservatism in the B&W computer codes when the Bellefonte analyses were being performed. B&W has several computer codes, including " POWER TRAIN,"

"CADDS," and " TRAP 2," which can be used to predict Reactor Coolant System i pressure following a decrease in heat removal by the secondary system. The.

1 computer code "CADDS" was used by B&W for the Bellefonte loss of feedwater i'

analyses. Apparently, "CADDS" predicts a lower Reactor Coolant System 4

pressure than one or more of the other computer codes available to B&W.

' TVA notes that the NRC has also raised a concern about the adequacy of "CADDS" in NUREG-0560.

l This nonconformance report (NCR) was deemed reportable because if a

! nonconservative computer analysis is used a potential exists for i overpressurization of the Reactor Coolant System. This NCR also indicates a possible failure of B&W's Quality Assurance program to resolve a known discrepancy in the analyses used to calculate Reactor Coolant System i pressure following an LOFW.

Interim Progrecs l TVA is continuing to work with Babcock and Wilcox (B&W) toward resolution of the subject deficiency. The resolution of this deficiency will be determined upon completion of' analyses being performed by B&W (Reactor Protection System Improvement Analysis and Loss-of-Feedwater Analysis).

TVA will evaluate the results of these analyses and determine the disposition of the subject NCR. The Bellefonte FSAR analysis is unique to B&W, and therefore no other TVA nuclear plants are affected.

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