ML20040H045
| ML20040H045 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/02/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20040H042 | List: |
| References | |
| NUDOCS 8202170050 | |
| Download: ML20040H045 (4) | |
Text
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 47 TO FACILITY OPERATING LICENSE NO. DPR-66 DUQUESNE LIGHT COMPANY OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY BEAVER VALLEY POWER STATION, UNIT NO. 1 DOCKET NO. 50-334 Introduction Duquesne Light Company, by letter to the NRC dated March 20, 1981, requested a change to the Appendix A Technical Specifications for Beaver Valley Power Station, Unit No.1.
The request was in response to a requirement identi-fied in a staff safety evaluation relative to an auxiliary feedwater system reliability evaluation that was forwarded to the licensee by letter dated February 7,1981. The enange to the Technical Specifications requires auxiliary feedwater system realignment to maintain adequate redundancy when the motor driven auxiliary feedwater pump aligned to the redundant header is declared inoperable. This safety evaluation also addresses the concerns relative to operator response time in the event of feedline rupture or main steam line break inside containment. The results of our review of the AFW pump endurance test forwarded by a letter dated May 22, 1981 is also included.
Discussion and Evaluation Short Term Recommendation 7 - The locked block valves in each AFW pump discharge line are aligned so that the combined flow from one motor driven pump plus one turbine-driven pump is supplied to the steam generators via one AFW header while flow from the remaining motor-driven pump is supplied to the steam generators via the redundant AFW header.
In the SER, the staff concluded that the alignment of the AFW system discharge block valves is acceptable for normal, transient, and accident conditions, subsequent to installation of check valves in the AFW steam generator supply lines. We further stated that the positions of the block valves continued to be of concern if the motor-driven auxiliary feedwater pump aligned to the redundant header were inoperable.
1 8202170050 820202 PDR ADOCK 05000334 P
. The licensee, in a letter to NRC dated March 20, 1981, forwarded a proposed revision to the BVPS Unit No.1 Technical Specifications, which added the following:
"With motor-driven auxiliary feedwater pump suppyling the redundant header inoperable, realign the two remaining auxiliary feedwater pumps to separate headers within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />."
We conclude that Recommendation 7 is adequately met, and therefore, acceptable.
Additional Short Term Recommendation 1 - The licensee should provide redundant level indications and low level alarms in the control room for the AFW system primary water supply to allow the operator to anticipate the need to make up water or transfer to an alternate water supply and prevent a low pump suction pressure conditions from occurring. The low level alarm setpoint should allow at least 20 minutes for operator action, assuming that the largest capacity AR4 pump is operating.
In the SER we stated that the licensee has met the short term requirements by provision of two channels for level indication and annunciation, with power supplied from a vital instrument bus backed up by battery power.
For the long term, we require the entire demineralized water storage tank level indication and alarm system to be designed to safety grade requirements including the use of class lE circuitry and power supplies. By letter dated July 21,1981, followed up by subsequent telephone conversations, the licensee has demonstrated that the intent of this requirement will be satisfied with the installation of the low-low level alarm system during the 1982 refueling outage. He conclude that this recommendation is adequately met.
Recommendation " Basis for Auxiliary Feedwater System Flow Requirements -
In the SER we stated that the licensee's responses of March 10,1980, to our questions on this subject showed that sufficient AFW flow could be delivered by the AFW system to meet the minimum heat removal requirements following any design basis transient or accident and assuming the worst case single active i
failure. We stated that the licensee should confirm that the Beaver Valley l
AR1 system can provide required flow for the feedline rupture and for the j
main steam line break inside containment without operator intervention for i
10 minutes. A review of the licensees' response of March 10, 1980, indicates that for the main feedwater line break no AFW flow is assumed for the first 10 minutes. At this time it is assumed that the operator has isolated the break and the minimum AFW flow requirement of 350 GPM commences.
This flow rate can be met by one motor driven AFW pump. As a result, peak reactor coolant system pressure will not exceed design pressure, and no consequential l
l l
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.. fuel failures occur. The NRC review of the applicant's responses also indicates that an AF14 flow rate of 350 GPM, starting 10 minutes after the accident, is sufficient to meet acceptance criteria for transients and.
accidents. Operator action to isolate the faulted steam generator 10 minutes after the accident has been accepted by NRC for other Westinghouse operating plants and operating license applicants. For the case of the main steam line break, the licensee's responses indicated that, because the steam line break results in plant cooldown, AR4 flow is not needed for the short tem. Again, isolation of the faulted steam generator is assumed 10 minutes after the break. The containment design pressure is not exceeded, even assuming operation of all ARI pumps.
Based on our review of the licensee's responses and our independant evaluation of this subject, we conclude that the Beaver Valley AFW system design will provide adequate AFW flow to meet design basis transients and accidents.
Additional Short Term Recommendation 2 - The licensee should perfom a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> endurance test on all AFW system pumps, if such a test or continous period of operation has not been accomplished to date. Following the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> pump run, the pumps should be shut down and cooled down and then restarted and run for one hour. Test acceptance criteria should include demonstrating that the pumps remain within design limits with respect to bearing oil temperatures and vibration and that pump room ambient conditions (temperature, humidity) do not exceed environmental qualification limits for safety-related equipment in this room.
(The pump endurance test requirement was reduced to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> by NRC letter dated January 22, 1980).
In a letter dated May 22, 1981, the licensee provided the results of the AFW pump tests. The tests were conducted in accordance with the conditions specified in our recommendations. The test data included flow rate, bearing oil temperature, and room environmental conditions. The licensee stated, and we concur, that these parameters were within the design limits. The licensee aiso provided a statement that pump
- vibration did not exceed l
allowable limits. We have reviewed the licensee's response and conclude l
that the Beaver Valley Unit 1 Auxiliary Feedwater System meets the requirements l
of this recommendation, and is, therefore, acceptable.
l Environmental Consideration We have determined that the amendment does not authorize a change in effluent l
types to total amounts nor an increase in power icvel and will not result in l
any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 651.5(d)(4),
that an environmental impact statement or negative declaration and environmental l
impact appraisal need not be prepared in connection with the issuance of this amendment.
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. Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant decrease in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date:
February 2,1982
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