ML20081H897
| ML20081H897 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 03/22/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20081H895 | List: |
| References | |
| NUDOCS 9503240427 | |
| Download: ML20081H897 (3) | |
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_ UNITED STATES E
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-E NUCLEAR REGULATORY COMMISSION
[
WASHINGTON, D.C. 20066-0001 SAFETY EVALUATION 8Y THE OFFICE OF NUCLEAR REACTOR REGULATION i
RELATED TO AMElWMENT NO.161 TO FACILITY OPERATING LICENSE NO. DPR-35
]
BOSTON EDIS0N COMPANY PILGRIN NUCLEAR POWER STATION DOCKET NO. 50-293 l
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1.0 INTRODUCTION
By letter dated September 6, 1994, as supplemented February 15, 1995, Boston Edison Company (BEco), the licensee for Pilgrim Nuclear Power Station, proposed the addition of.two new Technical Specifications (TSs) 3.7.B.I.f and 3.7.B.2.e, and proposed changes to existing TS 3.7.B.I.a. 3.7.B.I.c, i
3.7.B.I.e, 3.7.B.2.a and 3.7.B.2.c to the Pilgrim TSs. 'The above specifications deal with the standby gas treatment system (SGTS) and the control room high efficiency air filtration system (CRHEAF). Specifically, during refueling outages, BEco proposes to maintain one SGTS train and one CRHEAF train operable with both nonsafety-related and safety-related emergency 1
power sources while the redundant SGTS train and CRHEAF train are maintained operable with only normal nonsafety-related power sources. BEco's justification is that the changes would reduce refueling outage duration and j
that compensatory measures (the compensatory measures are incorporated as TS l
Additions 3.7.B.I.f and 3.7.B.2.e) will be taken to account for the i
nonavailability of a safety-related power source to one SGTS train and one j
CRHEAF train during refueling outages. The February 15, 1995, letter provided clarifying information that did not change the initial proposed no significant I
hazards consideration determination.
l 2.0 EVALUATION During refueling operations, fuel handling accidents (FHA) can occur resulting in release of radioactive materials to the environs.
In the event of a FHA j
during refueling operations, the SGTS performs its safety function, namely, l
limiting the release of radioactive materials to the environs and consequently i
limiting the offsite doses to below 10 CFR Part 100 limits. The plant TS i
" Bases" section for SGTS states-that only one of the two trains is needed to -
perform the system's safety function. The CRHEAF is a subsystem of the main l
control room environmental control system and its safety function is supplying a source of filtered outside air to the control room during an accident.
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This,. in turn, maintains the control room habitable by limiting the control room operator doses to within the 10 CFR Part 50, Appendix A, General Design j
Criteria 19 limits. The Final Safety Analysis Report, Section 10.17, states i'
that there are two independent trains of CRHEAF and that only one train is needed to provide the system's safety function.
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9503240427 950322 PDR ADOCK 05000293 i
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To account for nonavailability of emergency safety-related power sources for one SGTS train and one CHREAF train during refueling outages, BECo proposes j
the compensatory measures listed below for both the SGTS (See TS 3.7.B.1.f)
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and CRHEAF (See TS 3.7.B.2.e):
1.
Fuel movement will not occur until 5 days following reactor shutdown.
2.
Prior to and during fuel movement, the station blackout diesel generator or the shutdown transformer is required to be operable and capable of supplying power to the emergency bus.
3.
Fuel movement will not occur until the reactor vessel is flooded up to Elevation 114 feet to provide an enlarged coolant inventory.
4.
The SGTS train and CRHEAF train without their associated safety-related emergency power source will have power supplied from a normal offsite source via a non-safety-related bus. The normal offsite source consists of either the startup transformer or unit auxiliary i
transformer (backfeed mode).
If during refueling operations, either Compensatory Measure 2 or 4 given above cannot be met, or the SGTS train with emergency power source (i.e., with associated diesel generator) becomes inoperable by the TS definition (excluding its associated emergency power source availability), refueling operations can continue during the succeeding 7 days provided that within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> all the active components of the other SGTS train are demonstrated to be i
operable. The above action identified for the SGTS is also applicable to the CRHEAF.
The new TS, 3.7.b.1.f and 3.7.B.2.e allow one train of SGTS and CRHEAF to be operable without its safety-related bus and/or emergency diesel generator.
If there are no emergency diesel generators operable, irradiated fuel handling or new fuel handling over the spent fuel pool or core is not permitted.
The NRC staff recognizes that during refueling, the radiological consequences of an accident are less severe than during reactor operation in Modes 1, 2, or 1
3.
The NRC staff also agrees with BECo that the probability of a worst-case FHA coincident with loss-of-offsite power and a random failure of a SGTS or CRHEAF component in the train being fed from its associated safety-related emergency diesel generator is very low.
Based on the above findings, the NRC staff concludes that BEco's proposed TS changes, as identified in BEco's submittal dated September 6, 1994, are acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Massachusetts State official was notified of the proposed issuance of the amendment.
The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a i
facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined i
that the amendment involves no significant increase in the amounts, and no.
significant change in the types, of any effluents that may be released i
offsite, and that there is no significant increase in individual or cumulative i
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 (59 FR 53837). Accordingly, the amendment meets the eligibility 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 assessment need be prepared in connection with the issuance of the amendment.
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5.0 CONCLUSION
l The Commission has concluded, based on the considerations discussed above, 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 regulations, and (3) the issuance of the amendment will not be inimical to the common i
defense and security or to the health and safety of the public.
l Principal Contributor: Ronald B. Eaton Date:
March 22,1995
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