ML20082V321
| ML20082V321 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/03/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20082V319 | List: |
| References | |
| NUDOCS 9505090181 | |
| Download: ML20082V321 (5) | |
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NUCLEAR REGULATORY COMMISSION i
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s, SAFETY-EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i
RELATED TO AMElWNENT No. 68 TO FACILITY OPERATING LICENSE NO. NPF-73 DUQUESNE LIGHT COMPANY OHI0 EDISON COMPANY THE CLEVELAND ELECTRIC ILLUMINATING COMPANY THE TOLEDO EDISON COMPANY
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BEAVER VALLEY POWER STATION. UNIT 2 00CKET NO.' 50-412 t
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1.0 INTRODUCTION
By letter dated April 10, 1995, as supplemented April 12, 1995, and April 20, 1995, the Duquesne Light Company (the licensee) submitted a request for J
changes to the Beaver Valley Power Station, Unit 2 (BVPS-2), Technical i
Specifications (TSs). The requested changes would revise TS 4.6.2.2.d to l
delete the reference to the specific test acceptance criteria for the containment recirculation spray system pumps and replace the specific test acceptance criteria with reference to the-requirements of the Inservice Testing (IST) Program.
In addition, the 18-month frequency would be replaced with the test frequency requirements specified in the IST Program. The current footnote'(1) pertaining to the performance of containment recirculation spray pump 2RSS*P21A would be deleted. The April 20, 1995, i
letter provided clarifying information that did not change the initial proposed no significant hazards consideration determination.
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2.0 BACKGROUND
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The function of the containment recirculation spray system pumps is to take suction from the containment sump and discharge water to the spray rings located in the containment dome during a design basis accident. The sprayed water provides cooling for the containment atmosphere and will maintain the containment atmosphere at a negative pressure with respect.to the outside.
atmosphere after initial depressurization by the quench spray system and the recirculation spray system.
The recirculation spray system consists of two redundant trains with two pumps in each train. During the recirculation phase, one of the two pumps in each
' train continues to operate in the spray mode while the second pump in each train is automatically realigned to provide flow to the emergency core cooling system to remove decay heat from the reactor core in the long term. The remaining pump in each train that continues to provide flow in the spray mode maintains the containment subatmospheric in the long term.
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- The recirculation spray system pumps are flow tested during refueling outages by installing a temporary dike in the lowest floor elevation of the i
containment around the safeguards sump area to ensure adequate net positive suction head for the pumps during pump testing.
Flow to the spray headers is then blocked and pump discharge in returned to the sump area via installation j
of a spoolpiece into the test loop flow path.
TS 4.6.2.2.d requires the pumps to demonstrate their operability by developing 2 112 psid at a f: low of 2 3500 gpe. This acceptance criteria was temporarily reduced to 2110 psid at a flow of 2 3275 gpa by License Amendment No. 62 l
which Nas issued on August 22, e ?4. However, this temporary approval expired at the beginning of the unit's fifth refueling outage on March 24, 1995.
Pump 2RSS*P21A failed the requirements of TS 4.6.2.2.d when tested on April 1, 1995. Therefore, pump 2RSS*P21A was declared inoperable. Subsequently this pump was removed and inspected. A 1-inch diameter by 5-inch long stainless-steel bolt was discovered lodged in a pump inpeller. Some minor damage had i
occurred to the impeller and pump casing. The pump is a two stage pump, therefore, both impellers were replaced and the casing was repaired. Upon i
retest, the pump again failed the TS requirements. Therefore, the licensee
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submitted the April 10, 1995, license amendment request.
3.0 EVALUATIQN i
The proposed change to TS 4.6.2.2.d would delete reference to the specific test acceptance criteria for the recirculation spray system pumps and replace these criteria with reference to the requirements of the Inservice Testing (IST) Program.
Future changes in the pumps' minimum operating point could then be made by the licensee in accordance with the provisions of 10 CFR i
50.59, without requiring prior NRC staff approval and a license amendment unless an unreviewed safety question is involved. During its review of the April 10, 1995, submittal, the NRC staff became concerned that the provisions of the IST Program, o*.her than reference to the frequency specified in the IST program, could permit axcessive degradation of the pumps to be considered acceptable. Therefore, in a telephone conference call on April 12, 1995, the i
NRC staff requested that reference to the provisions of the IST Program, other j
than reference to the fregeency specified in the IST program, be deleted from proposed TS 4.6.2.2.d.
The licensee agreed with the NRC staff's concern and by letter dated April 12, 1995, submitted a revision to proposed TS 4.6.2.2.d' deleting reference to the provisions of the IST Program regarding pump performance.
% ring the April 12, 1995, telephone conference call, the NRC staff also requested that if pump 2RSS*P21A did not meet the criteria of TS 4.6.2.2.d following repair of the pump, the licensee should submit for NRC review, the licensee's engineering evaluation of the revised pump performance values for developed differential pressure and flow. By letter dated April 20, 1995, the licensee submitted the requested engineering evaluation.
This submittal includes a revised developed pump head curve for pump 2RSS*P21A. The revised developed pump head curve was then used to establish acceptable and unacceptable pump performance criteria considering the number of tubes plugged in the associated recirculation spray system head exchanger. The NRC staff i
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, has reviewed the licensee's evaluation and has determined that the a.ulysis methods and assumptions have not changed and that the licensee's analyses follow standard engineering practices. The licensee's evaluation demonstrates that following a design basis accident, the containment will depressurize in 1ess than I hour and that subatmospheric conditions will be maintained in the containment thereafter, as stated in the Updated Final Safety Analysis Report.
The NRC staff subsequently determined that TS 4.6.2.2.d, as proposed in the April 12,1995,14tter, did not provide an adequate limit on pump performance.
Therefore, during a telephone call on April 28, 1995, the NRC staff and licensee representatives agreed to further modify TS 4.6.2.2.d to specify that i
the pump's performance shall be as specified in the IST Program and in the containment integrity safety analysis which prohibits the excessive pump degradation which could otherwise be permitted by the IST Program. Therefore, we have determined that the proposed TS change, as revised, is acceptable.
The proposed amendment would also delete footnote (1) of TS 4.6.2.2.d.
This.
footnote is no longer applicable and therefore, its deletion is acceptable.
The proposed amendment would change the frequency for demonstrating the l
operability of the recirculation spray system pumps from once-per-18-months to the frequency specified in the IST Program (each refueling outage). This-change is consistent with current NRC staff guidance and requirements, as reflected in the NRC's improved Standard Technical Specifications (NUREG-1431, Revision 0), and is, therefore, acceptable.
4.0 EXIGENT CIRCUMSTANCES
i On April 10, 1995, the licensee requested that the proposed license amendment be processed as an exigent TS change in accordance with 10 CFR 59.91(a)(6).
Exigent processing was requested because BVPS-2 entered Mode 5 for the purpose of performing its fifth refueling outage on March 25, 1995, and upon completion of testing of Recirculation Spray Pump 2RSS*P21A on April 4, 1995, the licensee concluded that this pump failed to satisfy the specific test acceptance criteria in TS 4.6.2.2.d.
Pump disassembly for inspection and repairs commenced on April 5, 1995. The pump was reassembled and flow tested on April 18, 1995, at which time the licensee determined that the pump had again marginally failed to satisfy the requirements of TS 4.6.2.2.d.
EVPS-2 is currently scheduled to enter Mode 4 on May 4, 1995, at which time pump 2RSS*P21A is required to be operable.
Unless TS 4.6.2.2.d is revised, BVPS-2 will be prohibited from entry into Mode 4.
With the proposed revision to TS 4.6.2.2.d, the actual performance of pump 2RSS*P21A could then tv evaluated against accident analysis assumptions and the pump's acceptance criteria could then be revised under the provisions of 10 CFR 50.5C to establish IST Program requirements that would continue to maintain the plant within the accident analysis assunptions.
The licensee could not have foreseen this event since the pump's performance could not be tested until the plant entered Mode 5 on March 25, 1995. Therefore, we conclude that a license amendment pursuant to 10 CFR 50.91(a)(6) should be processed.
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5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION The Connission has made a final determination that the amendment involves no significant hazards consideration. Under the Commission's regulations in with the propos)ed amendment would not (1) Involve a significant increase the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
The Consission has evaluated the proposed changes against the above standards as required by 10 CFR 50.91(a) and has concluded that:
A.
The proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated (10 CFR 50.92(c)(1)) because they do not involve a change in the design or operation of the facility, nor do they affect the response of the facility to an accident. Since the proposed changes merely involve a surveillance requirement for devices which are used in the mitigation of an accident, they will not affect the operation of the equipment.
Furthermore, none of the failure modes of the recirculation spray system pumps are accident initiators, and any failure would be detected during the proposed surveillance requirements. The revised surveillance requirements will continue to provide adequate assurance that the equipment will perform its specified function if called upon to do so.
B.
The proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated (10 CFR 50.92(c)(2)) because the changes do nut affect the manner by which the facility is operated or involve any changes to equipment or features which affect the operational characteristics of the facility.
C.
The changes do not involve a significant reduction in a margin of safety (10 CFR 59.92(c)(3)) because they do not affect the manner by which the facility is operated or involve equipment or features which affect the operational characteristics of the facility.
6.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment.
The State official had no comments.
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7.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no l
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-5 significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (60 FR 19417). The Commission has made a final determination that the amendment involves no significant hazards consideration. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pur'suant to 10 CFR St.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
8.0 CONCLUSION
The Conuilssion has concluded, based on the consideratioris discussed above, that because the requested changes do not involve a significant increase in the probability or consequences of an accident previously evaluated, do not create the possibility of an accident of a type different from any evaluated previously, and do not involve a significant reduction in a margin of safety, the amendments do not involve a significant hazards consideration and that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulation ~s, and (3) the issuance of the amendment will not be inimical to the conenon defense and security or to the health and safety of the public.
Principal Contributor: Donald S. Brinkman Date: thy 3,1995
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