ML20203A211
| ML20203A211 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/23/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20203A208 | List: |
| References | |
| NUDOCS 9802230303 | |
| Download: ML20203A211 (4) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION E
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 212 TO FACILIW OPERATING LICENSE NO. DPR-65 NORTHEAST NUCLEAR ENERGY COMPANY THE CONNECTICUT LIGHT AND POWER COMPANY b
AND WESTERN MASSACHUSETTS ELECTRIC COMPANY MILLSTONE NUCLEAR POWER STATION _ UNIT 2 QOCKET NO. 50-336 5
1.0 INTRODUCTION
By letter dated September 3,1997, Northeast Nuclear Energy Company, et al. (the licensee) proposed a license amendment that would allow changes to the description of Millstone Nuclear Power Station, Unit 2, in the Updated Final Safety Analysis Report (UFSAR). The licensee determined that the requested changes constitute an unreviewed safety question as defined in 10 CFR 50.59. The proposed changes would allow tha utilization of a nonseismic underground storage tank to provide makeup for the required minimum inventory of fuel oil needed for continuous operation of one onsite emergency diesel generetor (EDG) for 7 days and the other onsite EDG for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following a design basis loss-of-coolant accident (LOCA). of the September 3,1997, letter provided marked up pages of the UFSAR reflecting the proposed changes.
2.0 BACKGROUND
There are two EDGs for Millstone Nuclear Power Station, Unit 2 (MNPS-2). Each EDG is provided with a separate fuel oil supply (FOS) system, which consists of a FOS tank and associated piping, valves, and instrumentation controls. Current TSs require a minimum of 12,000 gallons of fuel oil to be storad in each FOS tank (T-48A and T-488). A cross-tie with two locked-close valves for the FOJ.anks is provided so that a total inventory of 24,000 gations would be available to either one of the EDGs. The FOS system for each EDG including the cross-tie for the FOS tanks is weismic Category I design.
In addition, a 25,000-gallon underground fuel oil storage tank (T-47A), which is common for both EDGs, is provided to receive fuel oil from the delivery trucks prior to placing fuel oil in the FOS tanks. Upon arrival at ihe site, fuel oil in the delivery truck is sampled and tested for appearance, flash point, and kinematic viscosity in accordance with the MNPS-2 procedure,
" Fuel Oil Delivery Sampling Requirements." If test results are acceptable, the delivery truck is 9802230303 900123
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. off-loaded to T-47A tank. An additional sample from the delivery truck is sent to an offsite laboratory for analysis in accordance with MNPS-2 surveillance procedure, " Diesel Generator Fuel Oil Sampling." After off-loading is complete, T-47A tank is sampled to verify that the combined fuel oil meets the applicable requirements of American Society for Testing and Materials (ASTM) D975. In addition, the tank is sampled once per month for water and color in accordance with MNPS-2 surveillance procedure, " Sampling & Inventory of Diesel Oil Storage Tank, T-47A," and is also sampled every 92 days to verify that the fuel oil meets ASTM D975 requirements.
Normally, fuel oil stored in T-47A tank is transferred by two 25-gpm fuel oil transfer pumps to
. the FOS tanks. One fue! oil transfer pump supplies fuel oil to one FOS tank. However, there is an inter-connection with a locked-close valve in the transfer pump discharge piping so that each transfer pump can supply fuel oil to either FOS tank T-48A or T-488. The T-47A tank, the two 25-gpm fuel oil transfer pumps and their associated piping (between the storage tank and the EDG tanks), and valves are nonseismic designed.
I During the licensing application for MNPS-2, the combined fuel oil inventory (a minimum of 24,000 gallons) stored in the FOS tanks was determined to be sufficant for one EDG to operate for approximately 7 days plus the other EDG for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following a LOCA. Thus, the EDG fuel oil inventory for MNPS-2 satisfied the licensee's commitment stated in the FSAR regarding compliance with the Institute of Electrical and Electronic Engineers (IEEE) Std. 308-1971.
-Tesrefore, the staff concluded that the EDG fuel oil storage and transfer systems were acceptable in the Safety Evaluation Report, dated May 10,1974.
in July,1994, the licensee identified that, due to the original methodology (a best estimate methodology, which predicted a maximum load of 2298 kW) used in the fuel oil consumption rate calculation and increases in the electrical loads on the EDGs since plant startup (from 2298
- kW to current 2616 kW), the fuel oil inventory in the combined FOS tanks, as previously detailed, was no longer sufficient for 7 days continuous operation of one EDG plus the other EDG for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following a LOCA.
New EDG run time calculations were performed assuming that both FOS tanks are at the TS limit of 12,000 gallons. Both EDGs will operate initially at the continuous rated loads of 2750 kW for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at which time one of the EDGs will be secured and the other EDG will continue operation at its rated load by cross-connecting the two FOS tanks. Results of the calculations indicate that the above cited combined fuel oil stored in the FOS tanks will allow two EDGs to operate for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and then allow one of the EDGs to continue to operate for a total of approximately 3.5 days. The total volume of fuel oil required for two EDGs to initially operate for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and then allow one of the EDGs to continue to operate at its rated load for a total of 7 days is 41,515 allons.
G MNPS-2 smergency plan procedures require an evaluation of the need to order additional fuel from offsite sources within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following a LOCA or loss of normal power (LNP). The licensee stated that the change to the two EDGs initial operation time from i hour to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> will provide sufficient time for manning the Technical Support Center, provide load shedding recommendations, determine the need for additional fuel oil, order any required fuel oil, and monitor the delivery of the fuel oil to the site.
3 3.0 EVALUATION Normal make up to the EDG FOS tanks is supplied via T-47A tank. It contains fuel oil which is fully qualified and tested regularly as described cbove. If a seismic cvent occurs, the fuel oilin T 47A tank cannot be relied upon; however, replenishment of fuel oil in the FOS tanks could be accomplished directly from delivery trucks via offsite sources. The bensee stated that the requirement of fuel oil (approximately 17,700 gallons) to be stored in T-47A tank will be added to the Technical Requiraments Manual and will be verified by a surveillance requirement, which is similar to TS Surveillance requirement 4.8.1.1.2.a.1 required to verify the EDG fuel oil inventory in tanks T-48A and T-488. The T-47A tank low level alarm will be set at approximately 92 inches to ensure that a useable volume of 17,700 gallons is maintained in the tank. The associated glarm procedure will provide guidance to restore the required T-47A tank volume.
1 in addition, as previously noted, the MNPS 2 emergency plan procedures require an evaluation of the need to order additionel fuel from offsite sources within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following a LOCA or LNP l
and require the Technical Support Center staff to provide load shedding recommendations within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> cf a LOCA or LNP. The load shedding recommendations may include securing one EDG, cross connecting the two FOS tanks, and securing any electricalloads not needed io support dnt recovery depending on the plant conditions.
The staff concludes, based on its review of the licensee' uroposed revision to the UFSAR and the licensee's commitment to the actions described aboSe to ensure the required EDG fuel oil supply inventory, that there will be an adequate and relicble fuel oil inventory for 7 days of I
co.itinuous EDG operation following a LOCA or LNP at MNPS-2. Therefore, the staff finds the proposed revision to the UFSAR, as described in Attachment 3 of the licensee's submittal, acceptable.
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the emendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation oi use of a facility component located within the restricted area as defined in 10 CFR Part 20. The amendment also relates to changes in record keeping, reporting, or administrative procedures or requirements. The NRC staff has determined that the amendment involves 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 significant increase in individual or cumulative occup.stional radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there nas been no public comment on such finding (62 FR 50009 dated September 24,1997). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and (10). Pursuant to 10 CFR 51.22(b) no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
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6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public wil; not be 'ndangered by operation in the proposed manner, (2) such activities will be conducted in (,tipliance with the i
Commission's regulations, and (3) the issuance of the amendment will not be ;nimical to the common deferise and security or to the health and safety of the public.
Principal Contributors: D. Chum D. Mcdonald Date:
January 23, 1998 I
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