ML20043B240
| ML20043B240 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 05/21/1990 |
| From: | Shemanski P Office of Nuclear Reactor Regulation |
| To: | Kovach T COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20043B241 | List: |
| References | |
| TAC-74116, NUDOCS 9005250131 | |
| Download: ML20043B240 (4) | |
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UNITED STATES j'o NUCLEAR REGULATORY COMMISSION l
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May 21, 1990 Docket Nos. STN 50-454, STN 50-455 STN 50-456, STN 50-457 Mr. Thomas J. Kovach Nuclear Licensing Manager Commonwealth Edison Company-Suite 300 OPUS West III 1400 OPUS Place Downers Grove, 1111r.ois 60515
Dear Mr. Kovach:
SUBJECT:
IMPLEMENTATION OF SEISMIC STOPS AT BYRON STATION, UNIT NO. 2 (TACNO.74116)
References:
1.
Memo from L. N 01shan, NRR/PDilI2, " Meeting Summary - Non-Linear Piping Analysis Used to Justify Removal of Snubbers and Pipe Supports," dated May 24, 1989 2.
Letter from R. A. Chrzanowski, CECO to T. Murley NRC, "Non-Linear Piping Analysis to JustIf and Pipe Supports" (with attachments)y Removal of, Snubbers dated July 14, 1989 OnMay2,1989,CommonwealthEdisonCompany(CECO)proposedatameetingwith theMechanicalEngineeringBranch(EMEB)(Reference 1)todemonstratethe implementation at Byron Unit No. 2 of a new type of seismic restraint termed
" seismic stop." This restraint was developed by a CECO contractor, Robert L.
Cloud Associates (RLCA), as an alternative to snubbers and other types of seismic restraints. The seismic stop is claimed to permit totally free piping thermal expansion, provides restraint to dynamic loading through impact with fixed stops and requires little in-service maintenance and inspection.' Since these are highly non-linear devices RLCA has also developed a computer prcgram (GAPPIPE) for evaluating the response of piping systems containing seismic stops, based on standard dynamic analysis methodology and equivalent linearization/ iterative procedures.
A description and verification of this program was provided in Reference 2, where NSC approval by February 1990 was also requested so that modifications could be made at Byron Unit No. 2 during its second refueling outage scheduled for September 1990.
The demonstration for Byron Unit No. 2 will consist of replacing 13 snubbers on reactor coolant loop bypass line (2RC04/19) with 8 seismic stops. The number of stops and required sizes were determined by using GAPPIPE. The objective of this demonstration is to determine if all snubbers on balance-of-plant piping at Byron /Braidwood can be replaced with these stops.
9005250131 900521 4
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Thomas J. Kovach- -
The EMEB-staff and its consultant, the Brookhaven National Laboratory (BNL) have reviewed the basis for the implementation of the stops and the procedures i
of GAPPIPE; this review is provided in the enclosed Safety Evaluation Report 1
(SER).
Based on its review, the staff has concluded the following:
1 1
1.
Seismic stops appear to represent, from a safety point of view, acceptable devices for restraining safety related piping subjected to seismic and other dynamic excitation.
~2.
The theoretic 6i basis for the program GAPPIPE appears to be based on sound principles in accordance with the present state-of-the-art of piping analysis.
Based on these conclusions, we find the proposal to implement the pilot study at Byron Unit No. 2 acceptable, subject to the conditions stated in Section IV of the SER. This acceptance is applicable exclusively to Bryon Unit No. 2.
Sincerely,
/s/
Paul C. Shemanski, Project Manager Project Directorate 111-2 Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
Safety Evaluation Report cc w/ enclosure:
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L Mr. Thomas J. Kovach
- The EMEB staff and its consultant, the Brookhaven National L6boratory (BNL) have reviewed the basis for the implementation of the stops and the procedures of GAPPIPE this review is provided in the enclosed Safety Evaluation Report (SER). Based on its review, the staff has concluded the following:
1.
Seismic stops appear to represent, from a safety point of view, acceptable devices for restraining safety related piping subjected to seismic and other dynamic excitation.
2.
The theoretical basis for the program CAPPIPE appears to be based on sound principles in accordance with the present state-of-the-art of piping analysis.
Based on these conclusions, we find the proposal to implement the pilot study at Byron Unit No. 2 acceptable, subject to the conditions stated in Section IV of the SER.
This acceptance is applicable exclusively to Bryon Unit No. 2.
Sincerely, fr O
D8 or Paul C. Shemanski, Project Manager
/
Project Directorate 111 2 Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
c Safety Evaluation Report cc w/ enclosure:
See next page 9
8 i
4 Mr. Thomas J. Kovach Byron /Braidwood Power Station i
Comonwealth Edison Company Units 1 and 2
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cc:
Mr. Gabe Toth U. S. Nuclear Regulatory Comission Westinghouse Electric Corporation Byron / Resident Inspectors Office Energy Systems Business Unit 4448 North German Church Road Post Office Box 355, Bay 236 West Byron, Illinois 61010 Pittsburgh, Pennsylvania 15230 Ms. Lorraine Creek t
Joseph Gallo, Esq.
Rt. 1, Box 182 Hopkins and Sutter Manteno, Illinois 60950 SBB 16th Street, N.W.
l Suite 700 Mrs. ?hillip B. Johnson t
Washington, D.C. 20006 1907 Stratford Lane Rockford, Illinois 61107 Regional Administrator U. S. NRC, Region !!!
Douglass Cassel. Esq.
799 Roosevelt Road, B169. #4 109 N. Derarborn Street Glen Ellyn, Illinois 60137 Suite 1300 Chicago, Illinois 60602 Ms. Bridget Little Rorem Appleseed Coordinator David C. Thomas, Esq.
117 North Linden Street 77 S. Wacker Drive Essex, Illinois 60935 Chicago, Illinois 60601 Mr. Edward R. Crass Michael Miller Esq.
Nuclear Safeguards and Licensing Sidley and Austin Division One first National Plaza Sargent & Lundy Engineers Chicago, Illinois 60690 55 East Monroe Street Chicago, Illinois 60603 George L. Edgar Newman & Holtzinger, P.C.
U. S. Nuclear Regulatory Comission 1615 L Street, N.W.
Resident Inspectors Office Washington, D.C.
20036 RR#1, Box 79 Bracev111e, Illinois 60407 Comonwealth Edison Company Byron Station Manager Mr. Thomas W. Ortciger, Director 4450 North German Church Road 1111 noir. Emergency Services Byron, Illinois 61010 and Disaster Agency 110 Eatt Adams Street Springf,ield, Illinois 62706 1111 nots Department of Nuclear Safety Officts of Nuclear Facility Safety 1035 Juter Park Drive Springfield, Illinois 62704
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