ML20010F683

Final Deficiency Rept Re Pipe Supports,Initally Reported on 810406.Design Criteria N4-60-D717 Is Adequate for Use in Design of Supports for Piping Analyzed by Alternate Criteria & Does Not Need Revision

ML20010F683
Person / Time
Site:	Bellefonte
Issue date:	09/03/1981
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 8109110164
Download: ML20010F683 (4)

Text

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                  .        ,                       TENNESSEE VALLEY AUTHORITY CH ATTANOOG A, TENNESSEE 374ot
                                                      ' 400 Chestnut Street Tower II September 3, 1981                                y     -{

v ...- BLRD-50-438/81-31 " o g e BLRD-50-439/81-34 7,o Mr. James P. O'Reilly, Director D SEP 1019815 - ' u C'= Office of Inspection and Enforcement i ms.Huctan nouce: U.S. Nuclear Regulatory Commission \ " * " ' Region II - Suite 3100 101 Marietta Street

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Jf Atlanta, Georgia 30303 ' .. -- eear Mr. O'Reilly: BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - DEFICIENT PIPE SUPPORTS - BLRD-50 438/81-31, BLRD-50-439/81 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. Enclosed is our final report. TVA does not now consider 10 CFR Part 21 to be applicable to this deficiency. 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 &D35 L. M. Mills, Manager Nuclear Regulation and Safety Enclosure oc: Mr. Victor Stello, Jr., Director (Enclosure) Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 raf 8109110164 810903 gDRADOCK 05000438 I/ PDR An Equal Opportunity Employer

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l l ENCLOSURE I BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 DEFICIENT PIPE SUPPORTS BLRD-50-438/81-31, BLRD-50-439/81-34 10 CFR 50.55(e) 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 the pipe might not have sufficient clearance to move in a direction that is specified as unrestrained without contacting the support structure. The alternately analyzed piping supports have not been analyzed for any loading which would cause a displacement of this nature. In addition, TVA hanger personnel did not know the meaning of the symbol (^') . This was noted in inspection report 81-14 and was identified as , Violation 81-14-02. Safety I=olications Should pipe supports be inadequately designed cr installed, loading configurations resulting from accident conditions could result in support failures. The severity of safety implications depends on the proportions of any failure (s). Where the supports failed in such a manner as to directly or indirectly cause a failure of a safety-related system or piping, the safety of operations of the plant could be adversely affected. Corrective Action Before tnis NCR vas identified, the NRC resident inspector at BLNP cited TVA with a Severi.y 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 this symbol. In review of the support detail design sheets, an additional concern was identified by TVA piping ana.. '. This concern arose when the adequacy of the support design for possible ;ismic movement of alternately analyzed pipe was questioned. It was not clear that the support design was adequate i for all possible seismic movements (in unrestrained directions) for the alternately analyzed 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.

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                                                                                        .w Violation 81-14 Because TVA Hanger Installation personnel did not know the meaning of the symbol (~9, ITT Grinnell support designers were consulted as to its meaning. The designers stated that per ITT engineering i            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 i movement indicated must be assumed in the unrestrained direction (see 1 attached Appendix A), and a line drawn through the movement box on the support sketch form. The symbol @w9 indicates a 1/4-inch movement. TVA will ensure that all personnel required to know the meaning of the l symbol Gw0 are educated as to its meaning before further installation. TVA I will review the affected support designs and will inspect the installation to assure that sufficient clearance is provided. The inspection will be completed by December 1782. 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. J TVA determined that the support design criteria and the design drawings 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 placement of unidirectional supports. The review showed that at these locations the maximum seismic deflections in the unrestrained directions were neglible.

i Therefore, neither the Bellefonte Alternate Design Criteria nor the l Bellefonte Nuclear Plant Design Criteria N4-50-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

! to move in an unrestrained direction. l 1 l i l [

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l, ATTACHMENT i APPENDIX A l ITT GRINNELL ENGINEERING INSTRUCTIONS INSTRUCTION NO. 10, R6 0F 7-28-80 -

                                                                              "SPECIAL REQUIREMENTS" SECTION J Friction

1. 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. When a 1/4-inch movement is assumed, draw a line through the movement box on the rough - sketch form. Therefore, friction should be considered. 4

2. Frictio. shall be dynamic and will not require evaluation unless

the fcreed displacement is 0.0625 inches or greater. The coefficient will be 0.33 for steel to steel regardless of l composition and/or surface conditions under load. For restrained .

directions, friction is to be assumed as nonexistent regardless of construction gaps. I i f l l l l l l l t [

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