ML20195D670
| ML20195D670 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/01/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20195D623 | List: |
| References | |
| NUDOCS 8811070097 | |
| Download: ML20195D670 (5) | |
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WASHING TON, D. C. 20666
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i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.120 TO FACILITY O_PERATING LICENSE NO. OPR-3 YANKEE ATOMIC ELECTRIC COMPANY
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YANKEE NUCLEAR POWER STATION DOCKET NO. 50 029
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INYRODUCTION l
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By letter dated June 27, 1988 Yankee Atnmic Electric Coinoany (YAEC or the i
licensee) submitted a request for changes to the Yankee Nuclear Power Station l
i (YNPS or the plant) Technical Specifications (TS).
The amendeent would change the TS as follows:
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1.
Add valves WC-MOV-603. -605, and -615 to the surveillance requirements of TS 4.5.2.b.1. regarding valve position and power to the motor 7
operators.
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Change the function qf valve WC-V-622 in section C.2 of Table 3.6-1 of the TS. from spare penetration check valve to Water Clean-Up System t
l (WCS) return check valve. This merely represents a name change.
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3.
P.emove valve WC-V-621 from section B.1 of Table 3.6-1 and add valves WC-MOV-618 and -619 to section 0.1 of Table 3.6-1.
This represents replacing WC-V-621 with the valves WC-MOV-618 and -619 as the outside i
containment isolation valves in the WCS return line penetration, i
DISCUSSION I
The reason for this proposed change is to provide for two piping modifications t
necessary for installation of an enhanced Water Clean-Up System at the Yankee plant. The WCS is being added to process low level radioactive waste generated during normal plant operation and to remove radioactive cesium and iodine from recirculating water via the containment sump following a loss of coolant accident.
The licensee is preparing to make this change, addition of WCS. to the facility l
under the provisions of 10 CFR 50.59. This analysis is subject to audit by the NRC.
t The following safety evaluation relates specifically to the three TS chan;es listed above.
In evaluating these changes the staff also evaluated systems interactions
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between the WCS and the Low Pressure Safety injection System. We applied the requirements of 10 CFR 50 Appendix A. General Design Criteria (GDC) 54. 55. 56 and 57 in our evaluatioa of the containment piping penetrations and to containment 2
isolation capability.
In regard to leak testing of the subject valves in containment
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penetrations we applied the requirements of 10 CFR 50 Appendix J that relate to 1
I containment isolation valve leakage testing and allowable leakage rates, namely
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Type C testing of Appendix J.
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' l EVALUATION The first proposed change is ne addition of valves WC-MOV-603, -605 and i
-615 to TS 4.5.2.b.1.
These three valves, during normal operation, will isolate the WCS from the Low Pressure Safety injection (LPS1) System.
In a post-accident situation the valves would be opened and supply recirculated containment sump water, which would be highly radioactive, through the LPSI System to the WCS for clean-up.
Valves -603 and -605 would serve as l
throttling valves, post-accident, to divert 50 gpm of the total 350 gpm LPSI flow to the WCS.
The remaining 300 gpm flow to the LPSI System is l
much more than needed for decay heat removal from the core, which is the post-accident function of the LPSI System.
The -615 valve, in addition to its isolation function, serves to provide ae LPS! pump, one of three in operation post-accident, with a flow path when LPSI recirculation is not j
required.
This flow path is needed for maintaining flow greater than or I
equal to 25% of the best pump efficiency flow during normal operation in order to fulfill the pump manufacturer's recommendations.
l These three valves do not serve any containment isolation function, thus, are not subject to GDC 54, 55, 56 or 57, nor to the containment leak test t
requirements of 10 CFR 50 Appendix J.
However, these valves will be tested and inspected under the provisions of 10 CFR 50.55a Codes and Standards, which requires inclusion of these valves in the YNPS pump and valve l
inservice test program. We have verified that the licensee has included th se valves in the inservice test program.
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The inclusier of these three valves in TS 4.5.2.b.1 ensures that the valve position in iormal operation will be closed and that power to the valve motor operators will be removed by opening at least two circuit breakers in series and that this configuration will be verified at least once per 31 days.
We conclude that the addition of these three valves to TS 4.5.2.b.1 is acceptable as it will maintain these valves in a configuration that isolates the LPSI from the WCS until an interconnection in a post-accident situation is required, he further conclude that these valves which serve to interconnect the WCS end LPSI system, post-accident, would not inadvertently defeat the primary purpose of the LPSI, namely to remove decay heat from the core af ter a loss-of-coolant accident. We base this conclusion on the requirements of TS 4.5.2.b.! to maintain these valves in a closed position with power removed from two circuit breakers in series to the motor operators on the valves. However; when the valves are opened, in a post-accident situation, it is done under procedural control several days after the accident. At that time there would be minimal stress on plant operatorsensurinyon,mpliancewiththeapplicableprocedurestoopenthese co valves.
In addit the primary system would be depressurized and all LPSI system flow in a stable mode.
The second proposed change, that of renaming valve WC-V-622 from "Spare Penetration Check Valve' to "WCS Return Check Valve," does not change any of the required leak testing cr inspections required by 10 CFR 50. This is purely an administrative change due to the fact that the spare penetration
, the valve was a part of has become a penetration used by the WCS. Based on the above, we conclude the change in name and relocation within Table 3.6-1
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of the TS is acceptable.
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The third proposed chance is the replacement of valve WC-V-621 as the outside isolation valve in what was a spare penetration, with a pair of valves, in parallel. WC-MOV-618 and -619 The spare penetration is now to be used as the WCS return line penetration. This pipe line returns recirculated water from the WCS after fission products have been removed.
i This "clean" water is returned to the containment sump where it becomes a suction source for the LPSI pumps and is recirculated through the LPSI system with 50 gpm of the total 350 gpm flow being sent to the WCS for i
processing.
GDC 54 of 10 CFR 50 Appendix A requires that piping systems penetrating I
containment are provided with leak detection and isolation capability.
Such leak detection capability is provided by a valved pressure tap between the inside and outside isniation valves.
Isolation capability per GDC 56 is q
discussed below.
GDC 56 requires thr,t lines that connect directly to the containment atmosphere l
and penetrate con'cainment shall be provided with containment isolation i
valves. The WCS return line penetrates the containment with an inboard i
check valve (WC-V-62?) and two parallel outboard motor-operated valves (WC-MOV-618 and -619) serving as the containment isolation valves. These valves are subject to local leak rate (Type C) testing per the requirements of 10CFR50 Appendix J.
The WCS return line directs flow to the containment t
l sump. The two motor-operated valves in the line are normally closed with l
their motive power removed by two breakers in series. The staff finds I
that this valve arrangement complies with the isolation provisions specified l
in GDC 56.
in addition to the above. SRP Section 6.2.4 requires that the isolation valves be located as close to containment as possible to minimize the probability of a pipe rupture and valve leakage between the isolation valves. There are three manual valves (WC-V-621. -625, and -626) in the t
WCS return line located between the containment wall and the outboard i
containment isolation valves.
In a telecon with the licensee on October 19, 1988 the staff expressed the concern that the possible leakage of these three valves could impair the isolation function of the outboard
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containment isolation valves. To ensure the integrity of the line, the licensee consnitted to leak test these three manual valves periodically.
Based on the licensee's consnitment to test the three manual valves between the containment wall and containment isolation valves, and compliance with the requirements of GDC 54. GDC 56, and Appendix J for isolation valves l
VC-V 622. WC J0V-618. and WC-MOV-619. the staff concludes that the proposed change is acceptable, j
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ENVIRONMENTAL CONSIDERATION This amendment involves a change to a requirement with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment in-volves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no l
significant increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a proposed finding that this I
amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eiigi-bility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental I
assessment need be prepared in connection with the issuar.ce of this amendment.
l CONCLUSION I
The staff has concluded, based on the considerations discussed above, that:
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(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such I
activities will be ccnducted in compliance with the Comission's regulations f
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and the issuance of this amendment will not be inimical to the comon defer.se and security or to the health ani safety of the public, i
ACKNOWLEDGEMENT Principal Contributor: Porton B. Fairtile t
Dated: November 1, 1938 f
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NOV1 1988 Dated AltENDMENT fl0.120 TO FACILITY OPERATIllG LICENSE DPR-3, YAtlKEE fiUCLEAR POWER STATION Distribution:
Docket file 50-029 %-
NRC PDR Local PDR PDI-3 Reading S. Varga M. Fairtile M. Rushbrook OGC D. Hagan E. Jordan B. Grirnes T. Barnhart I4)
W. Jones E. Butcher ACRA (10)
GPA/PA ARM /LFNB
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