ML20085N591
| ML20085N591 | |
| Person / Time | |
|---|---|
| Site: | Shoreham File:Long Island Lighting Company icon.png |
| Issue date: | 10/28/1983 |
| From: | James Smith LONG ISLAND LIGHTING CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| SNRC-974, NUDOCS 8311110124 | |
| Download: ML20085N591 (4) | |
Text
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e LONG ISLAND LIGHTING COM PANY gg waam SHOREHAM NUCLEAR POWER STATION P.O. DOX 618, NORTH COUNTRY ROAD
- WADfNG RIVER, N.Y.11792 Dunt Dhl Number October 28, 1983 SNRC-974 Mr. Harold R.
Canton, Director Of fice of Nuclea.- Reactor Regulation U.S.
Nuclear Regulatory Commission Washington, D. C.
20555 Reactor Building Settlement Shoreham Nuclear Power Station - Unit 1 Docke t No. 50-322
Dear Mr. Denton:
As indicated in U.S. Nuclear Regulatory Commission Region I Inspection Report No. 50-322/83-06 (Item 4), the Long Island Lighting Company is establishing a settlement monitoring program for use throughout the life of the plant.
Relative to the set-tlement issue, your staff requested LILCO to provide settle-ment criteria for the following:
(1) absolute reactor building settlement, (2) differential settlement between the reactor building and adjacent structures, and (3) reactor building differential settlement (tilt).
Item (2), differential settlement between the reactor building and adjacent structures was felt to be the most limiting para-meter.
In order to determine a limiting value, a review was performed of pipe stress analyses and pipe support design calcu-lations for all of the piping spanning the reactor building and I
adjacent structures, including buried pipe.
This review concluded that all of the piping and supports could tolerate a differential l
settlement of at least 0.9 inch.
It should be noted that the l
maximum differential settlement that has occurred since the earliest installation of pipe / support combinations in December 1978 is 0.1 in.
Piping and supports can sustain at least an additional 0.8 in. of differential settlement throughout the remaining life of the plant.
This is nearly double the to h in. increase expected in total absolute settlement of the reactor building.
A limiting settlement value is not required for reactor building differential settlement (tilt).
Actual tilt measured to date is only 0.1 in. as shown in Figure SC of Appendix 2J of the FSAR.
I As noted above, future total settlement of the reactor building is l
expected to be uniform and less than in.;
therefore, reactor 8311110124 831028 g
PDR ADOCK 05000322 A
October 28, 1983 SNRC-974 Page 2 building tilt is expected to be insignificant throughout the life of the plant.
If the reactor building does tilt in the future, the most signifi-cant potential problem is expected to be an increase of loads on the piping due to anchor point rotation.
Of all of the piping connected to the reactor building, the buried service water lines are the ones that are most sensitive to anchor point rotations.
As explained further on in this letter, however, these lines can accommodate tilt of at least 2 in, without inducing cignificant additional stresses.
A limiting value of absolute settlement of the reactor building is not required because absolute settlement is much less critical than dif ferential settlement.
Absolute settlement of as much as 6 in, would not cause problems as long as the criteria for dif ferential settlements are not exceeded.
Absolute settlement of this magnitude, however, is not expected.
As stated above, the reactor building is expected to settle only an additional % to in. throughout the life of the plant.
Adding this to the present measured settlement of 3 in, results in an expected absolute settlement of 3.5 in, for the reactor building.
This should not be used as a settlement criteria, however, because exceeding this value does not indicate there is a problem.
Dif-forential settlement criteria should be used as a measure of settlement acceptability.
Settlement of the reactor building and reactor building tilt do not present a. problem for the buried pipes as discussed below.
The only Category I buried pipes that go to the reactor building are the service water lines.
These lines enter the reactor building through the service water pit, which is founded on the portion of the reactor mat that extends out beyond the secondary containment.
Therefore, settlement of the service water pit will be approximately equal to the settlement of the reactor building.
Settlement along the service water lines is expected to vary with distance from the reactor building, approximating the settlement of the service water pit at the penetration, and tapering off to zero at some distance from the reactor building.
Thus, the differential settlements experienced by the service water lines or the connection at the service water pit are expected to be very small.
Furthermore, the U-shaped routings of the service water lines in the service water pit are specifically designed to provide flexibility and can accommodate the limiting values of differential settlement and tilt with substantial margins.
The study described above concluded that the buried service water lines could tolerate at least 0.9 in. of differential settlement and at least 2 in, of reactor building tilt.
These lines were
J October 28, 1983 SNRC-974 Page 3 connected to the service water pit after December 1978.
Since then, the reactor building has settled only an additional 0.1 in.,
and future settlement of the reactor building is expected to be less than in, throughout the life of the plant.
Even if the service water lines do not settle as much as in.,
(the maximum expected settlement of the reactor building throughout the life of the plant), the differential settlement at the connection will still be less than the 0.9 in. design requirement.
Based. on the good agreement between actual and predicted values of settlement (as noted in Appendix 2J to the FSAR), the insig-nificant amount of recent settlement (since 1978), the relatively large difference between limiting settlement values and the smaller predicted settlement values, and LILCO's commitment to perform a settlement monitoring program during plant operation, no further action should be required for this issue.
LILCO trusts that the information submitted above satisfies the staff request.
Should you have any questions, please contact this office.
Very truly yours, A
'J L. Smith Manager, Special Projects Shoreham Nuclear Power Station RWG/ss cc:
C.
Pe trone All parties listed in Attachment 1 l
e
L 4
l ATTACHMENT 1 I
I Lawrence Brenner, Esq.
Herbert H. Brown, Esq.
Administrative Judge Lawrence Coe Lanpher, Esq.
Atomic Safety and Licensing Karla J. Letsche, Esq.
Board Panel Kirkpatrick, Lockhart, Hill U.S. Nuclear Regulatory Christopher & Phillips Commission 8th Floor Washington, D.C.
20555 1900 M. Street, N.W.
Washington,.D.C.
20036 Dr. Peter A. Morris Administrative Judge Mr. Marc W. Goldsmith Atomic Safety and Licensing Energy Research Group Board Panel 4001 Totten Pond Road U.S.
Nuclear Regulatory Waltham, Massachusetts 02154 Commission Washington, D.C.
20555 MHB Technical Associates 1723 Hamilton Avenue Dr. George A. Ferguson Suite K School of Engineering San Jose, California 95125 Howard University 2300 6th Street, N.W.
Washington, D.C.
20059 Stephen B.
Latham, Esq.
Twomey, Latham & Shea 33 West Second Street Bernard M.
Bordenick, Esq.
P.O. Box 398 David A.
Repka, Esq.
Riverhead, New York 11901 U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Ralph Shapiro, Esq.
Cammer and Shapiro, P.C.
9 East 40th Street Mr. James Dougherty New York, New York 10016 3045 Porter Street A-Washington, D.C.
20008 Matthew J. Kelly, Esq.
State of New York Department of Public Service Titree Empire State Plaza Albany, New York 12223 I
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