ML20010J510

Revised Final Deficiency Rept Re Deficient Pipe Supports, Originally Reported on 810406.Caused by Support Installation Engineer Error.Personnel Educated Re Meaning of Engineering Symbol.No Design Criteria & Drawing Revisions Needed

ML20010J510
Person / Time
Site:	Bellefonte
Issue date:	09/28/1981
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 8110050199
Download: ML20010J510 (3)

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, i 400 Chestnut Street Tower II

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& .. l, September 28, 1981 BLRD-50-438/81-31 BLRD-50-439/81-34

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Mr. Jases P. O'Reilly, Director (q Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Region II - Suite 3100

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101 Marietta Street _ , %iuID'cu/A Atlanta, Georgia 30303 r

Dear Mr. O'Reilly:

'O BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - DEFICIENT PIPE SUPPORTS -

BLRD-50-438/81-31, BLRD-50-439/81 REVISED FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector P. Taylor on April 6,1981, in accordance with 10 CFR 50.55(e) as NCR BLN BLP 8109 This was followed by our first interim report dated May 6, 1981 and our final report dated September 3, 1981. Enclosed is our revised final report. The reason for this revision is to clarify the description of the corrective action.

If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 857-2581.

Very truly yours, .

TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure ec: Mr. Victor Stello, Director (Enclosure) .

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Office of Inspection and Enforcement O ') /

U.S. Nuclear Regulatory Commission 3 Washington, DC 20555 I I C O!oh$g PDR

ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 DEFICIENCY PIPE SUPPORTS BLRD-50-438/81-31, BLRD-50-439/81-34 10 CFR 50.55(e)

REVISED FINAL REPORT ,

Description of Deficiency The Bellefonte Alternate Analysis Criteria imposes a seismic displacement limit of one inch for piping. It was not clear to TVA that seismic restraints were properly designed to allow for seismic displacement of the piping. It was hypothesized that tro pipe might not have sufficient clearance to move in a direction that is specified as unrestrained without contacting the suppori et"ucture. The alternately analyzed piping supports have not been analyzed tot any loading which would cause a displacement of this nature.

1 In addition, TVA hanger personnel did not know the meaning of the symbol

('w) . This was noted in inspection report 81-14 and was identified as Violation 81-14-02.

Safety Implications Should pipe supports be inadequately designed or in' ad, loading configurations resulting from accident cono tior'- . result in support failures. The severity of safety implicativas s g- on the proportions of any failure (s). Where the supports failed in st ch a manner as to (.;

directly or indirectly ause a failure of a sarety-related system or L' '

piping, the safety of operations of the plant could be adversely affected.

Corrective Action Before this NCR was identified, the NRC resident inspector at BLNP cited TVA with a Severity Level V Violation (81-14-02). The violation concerned the symbol G-3 which is used in the movement column on ITT Grinnell (ITT)

support detail design sheets. TVA_ support installation engineers were confused as to the meaning of thf.s symbol.

In review of the support detail design sheets, an additional concern was

, identified by TVA piping analysts. This concern arose when the adequacy of l the support design for possible seismic movement of alternately analyzed pipe was questioned. It was not clear that the support design was adequate for all possible seismic movements (in unrestrained directions) for the alternately analy7.ed pipe. The subject NCR was written as a result of this additional concern. TVA discussed the above violation and the piping analysts' concern in a telephone conference with the resident inspector on July 30, 1981. In that conference, the inspector agreed that the response to the violation and the response to the subject deficiency should be combined. Therefore, TVA discusses both conditions below. -

. Violation 81-14 Because TVA Hanger Installation personnel did not know the meaning of the symbol (es), ITT Grinnell support designers were consulted-as to its meaning. The designers stated that per III engineering instructions that if the movement column on the table of support loads indicates anything other than zero, then a 1/4-inch movement or the movement indicated must be assumed in the unrestrained direction (see Appendix A), and a line drawn through the movement box on the support sketch form. The symbol (^/) indicates a 1/4-inch movement in unrestrained directions only. For the directions in which a supp' ort is a rigid restraint, the movement will be zero.

TVA will ensure that all personnel required to know the meaning of the symbol (e s ) are educated as to its meaning before further installation.

TVA will review the affected support designs and will make the necessary inspections of the installed supports to assure that sufficient clearance is provided. The inspection will be completed by December 1982.

NCR BLN BLP 8109 - In regard to the concern about the adequacy of support design for alternately analyzed pipe, TVA has determined that the Bellefonte Nuclear Plant Design Criteria N4-60-D717, " Design of Safety-Related Piping Supports and Supplemental Steel," is adequate for use in the design of supports for piping analyzed by the alternate criteria and does not need to be revised.

s . TVA determined that the support design criteria and the design drawings

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are adequate after reviewing the computer analyses of seismic events obtained from EDS Nuclear, Incorporated (the developer of the alternate criteria).

The Bellefonte alternate criteria contains specific guidelines for pit. cement of unidirectional supports. The review showed that at these locations that maximum seismic deflections in the unrestained directions l were negligible.

Therefore, neither the Bellefonte Alternate Design Criteria nor the Bellefonte Nuclear Plant Design Criteria N4-60-D717, " Design of Safety-Related Piping Supports and Supplemental Steel," has been violated. All seismic restraints have been designed so as to allow sufficient clearance l to move in an unrestrained direction.