ML20049A348
| ML20049A348 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/26/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| 959, NUDOCS 8012040414 | |
| Download: ML20049A348 (4) | |
Text
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l VImOINIA EI.ecruzC AND Powem CoxPANY Ricumown,VamonmzA nuess November 26, 1980 Mr. Harold R. Denton, Director Serial No. 959 Office of Nuclear Reactor Regulation N0/RMB Attention:
Mr. B. Joe Youngblood, Chief Docket No. 50-339 Licensing Branch No. I License No. NPF-7 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Denton:
NRC REQUEST FOR ADDITIONAL INFORMATION LOW HEAD SAFETY INJECTION AND OUTSIDE RECIRCULATION SPRAY PUMP OPERABILITY NORTH ANNA UNIT NO. 2 This letter is to respond to a request for additional information concerning Low Head Safety Injection and Outside Recirculation Spray Pump operability on North Anna Unit No. 2.
The request for additional information was contained in a letter from the NRC staff dated November 5,1980.
Vepco and Stone and Webster have reviewed the NRC request and our response is as follows:
a.
Request A discussion of the anchoring details for each of these pumps, sup-plemented by drawings.
i
Response
(
The LHSI pumps, manufactured for Westinghouse by Ingersoll Rand, and the ORS pumps, manufactured by Bingham Willamette, are each flange i
mounted to a vertical can.
The can is anchored to the containment l
mat at elevation 215'-11" and shrouded above the anchor point by i
2 inches of foam material surrounded by concrete backfill.
The pump to can flanges are laterally restrained to the containment wall elevation 257'-10".
The LHSI pump motors are also laterally at restrained to the containment wall at elevation 263'-4".
Wedges and/or guides e.re used between pump columns and cans with different design schemes used by each manufacturer.
Enclosed is a listing of the drawings which depict the pumps, can, and methods of support.
EO1204M THIS DOCUMENT CONTAINS l
P0OR QUAUTV PG3 I
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Mr. Harold R. Denton, Director b.
Request For each pump the results of analysis which quantify the degree of relative moveaent of the containment with respect to the base mat.
Response
The calculated containment radial growth, at the pump lateral support elevation (257'-10"), relative to the containment mat is 0.98 inches based on conservative analysis of post accident pressure and tempera-ture conditions using the methodology for static analysis in Section 3.8.2.5.1 of the FSAR.
c.
Request A description indicating how the relative movement of the contain-ment could affect pump operability.
Response
The relative containment movement of 0.98 inches will not affect the ability of either the LHSI pumps or the ORS pumps to either start or operate satisfactorily.
Although the designs of the LHSI pump and the ORS pump differ in a few details, both pumps can be classified as long, flexible, vertical can-type.
Both pumps will respond similarly to a force or displace-ment imposed at its upper seismic restraints which are tied to the containment.
It is assumed that the deflection of 0.98 inches is taken over the length of the pump, between its upper seismic restraints and lower seismic guides (approximately 520 inches). The overall angle created by this deflection is less than six minutes of arc.
Both vertical pump designs can be expected to accommodate such a small movement with little or no bushing wear.
The deflection is not great enough to prevent a pump from starting or cause measureable bushing wear if it were to occur during operation.
Also, since both pumps are flexible members, based on length, the force required to deflect the combined pump and can 0.98 inches is estimated to be less than half the design load-carrying rating of the pumps' graphite bushings.
Such a load, consequently, if it were to occur during pump operation would not result in measureable wear.
Because of both factors, the operability of either pump will not be
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impaired by a short-term deflection caused by relative movement of the containment.
[
l r
vamonwea EtscTase amp Powsm Courawv o Mr. Harold R. Denton, Director d.
Request Your evaluation of the relative movement on pump operability.
Response
A number of steps have been taken to assure the verticality of both the cans and the LHSI and ORS pur:ps.
As a result of optically aligning both sets of pumps and cans and providing detailed pump assembly procedures to ensure the vertical alignment of the pumps, the pumps in its non-accident state can be considered centered and plumb.
The maximum movement of the upper seismic restraint will result in a total pump deflection of less than one inch at its highest point.
This is a short-term event which by calculation lasts less than one-half hour for the design basis accident. Even with the differences between the wedged LHSI and the ORS pumps with no wedges, the move-ment of the pumps laterally does not affect operability.
Futhermore, even with some bushing contact, pump operability is not directly affected.
Extreme deflection or distortion of running parts would have to occur before significant wear, or loss of operability could result.
~
We have reviewed this matter with the pump manufacturers and have received their verbal concurrence with the response given to items e and d above.
If you have any question or require additional information, please contact us.
Very truly yours, B. R.
ylvia Manager - Nuclear Operations and Maintenance sav:SP1 cc:
Mr. Robert A. Clark Operating Reactors Branch No. 3 Division of Licensing Washington, DC 20555 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement Region II Atlanta, GA 30303
e e
REFERENCE DRAWINGS Drawing No.
Title 11715-FC-15A & B Achorage Details in Mat 11715-FC14B, D, & E Containment Backfill Details 11715-FV-4A, B, & C Can & Can Restraint Details 12050-MFSK-2429A & B Motor Restraints 2-SI-P-1A 12050-MFSK-2430A & B Mbtor Restraints 2-SI-P-1B 12050-CBD-354A Motor Restraint Bracket F-25-2APK86X1-K Ingersoll Rand General File 11715/12050 - 2.29-1C Arrangement F-25APK500K5 Ingersoll Rand APK Pump &
Sheets 1 & 2 Wedge Lock Assemblies File 11715/12050 - 2.29-10A & 11A FD-200465/66 Bingham Pump, Gen. Arrangement File 11715/12050 - 2.21-3D G
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