ML20236K927
| ML20236K927 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 11/05/1987 |
| From: | Virgilio M Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236K909 | List: |
| References | |
| NUDOCS 8711100026 | |
| Download: ML20236K927 (8) | |
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7590-01 UNITED STATES NUCLEAR REGJLATORY COMMISSION DETROIT EDISON' COMPANY.
WOLVERINE POWER SUPPLY COOPERATIVE, INCORPORATED DOCKET NO 50-341-ENVIRONMENTAL ASSESSMENT AND FINDING 0F NO SIGNIFICANT IMPACT The U.S. Nuclear Regulatory Commission (the Commission) is considering issuance of an exemption from the requirements of General Design Criterion (GDC) 56 of Appendix A to 10 CFR Part 50 to the Detroit Edison' Company (DECO or licensee) for the Fermi-2 facility. The facility is a boiling water reactor located in Monroe County, Michigan.
ENVIRONMENTAL ASSESSMENT Identification of the Proposed Action:
The exemption would allow, for a limited period, a primary containment isolation scheme for the Primary Containment Radiation Monitor (PCRM) consisting of one set of automatic containment isolation valves and one set of remote-manual isolation valves which require operator action to close, rather than two sets of automatic containment isolation valves or other specified '
combinations of valves, as required by GDC 56 of Appendix A to 10 CFR Part 50.
This exemption would extend only until startup following the scheduled March 1988 outage required for local leak rate testing (LLRT). The exemption !
is in accordance with the licensee's application dated October 27, 1987, as I
supplemented by letters dated October 29, 1987, and November 2, 1987.
8711100026 871105 PDR ADOCh 05000341 P PDR
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~2-e The Need for the Proposed Action:
The Fermi-2 Containment Leakage Det'ection' System includes a PCRM configured in parallel with the Drywell Hydrogen /0xygen Sampling System )
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panel. Both systems norma 11y' operate during reactor operation and sample the l 1
drywell atmosphere from five zones through containment penetrations. The initial isolation design for.the PCRM and the Drywell Hydrogen /0xygen Sampling l System is described in Section 6.2.4 of the Fermi-2 Final' Safety Analysis Report. Containment isolation requirements of GDC.56 were achieved using a single automatic isolation valve and a cl~osed piping system outside'the containment, instead of one automatic isolation valve inside and one automatic isolation valve outside containment. As stated in Section 6.2 4 of the.
Commission's Safety Evaluation Report for Fermi-2, this design is acc&ptable. ,
The design intent was that the PCRM would operate _ following a loss-of-coolant accident (LOCA) and that the PCRM would be in compliance with the closed system -
requirements approved as an alternative to GDC 56. j In January 1984, the licensee determined that the PCRM did not ' comply with the closed system design requirements; specifically, for a containment design pressure:of 56 psig, the closure of the PCRM skid-mounted motor-operated valves-(MOVs) was required. These MOVs close automatically when a pressure signal, sensed immediately inboard of the valves, reaches two psig. Seismic and i
material certifications provided by the PCRM vendor also were found to be i
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f deficient. Two actions were taken by the licenste as a result of these findings: (1) the PCRM was reclassified as nonessential following a LOCA and, !
as such, should be isolated auto.natically.upon receipt of a LOCA signal (the j l
Drywell Hydrogen /0xygen Sampling panel retained its essential classification); j and (2) two solenoid-operated automatic'is91ation valves were added to the ;
branch line to the PCRM. The automatic isolation valves were added to provide _ l l isolation of toe reclassified nonessential PCRM. The automatic isolation valves 1 .
receive a closure signal'on;a high drywell pressure signal from the Reactor Protection System A and 8 trip systems.
The PCRM configuration installed in the plant'in January 1984 provides two-barriers in the event of a LOCA and failure of the PCRM boundary. One barrier ;
consists of the automatic isolation valves and the second barrier is provided by remote manual isolation valves. However, the use of a remote' manual 1 isolation valve as a barrier for a nonessential system (such as the current PCRM design) is not an acceptabic alternative to the requirements of GDC 56, .;
- and, thus, the existing design for the PCRM must be upgraded to fully meet the provisions for GDC 56. The licensee has, accordingly, proposed to redesign the PCRM providing two barriers, each consisting of two sets of automatic containment isolation valves, to fully meet GDC 56 requirements.
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The PCRM, in conjunction with the Drywell Hydrogen /0xygen Sampling System, is one of three Containment Leakage Detection Systems in the plant. The plant Technical Specifications (Section 3.4.3.1) require that all three detection systems be operable, and that with only two of the three systems operable, the inoperable system must be restored to operable status within 30 days otherwise the plant must be shut down following the 30-day period. The plant is currently
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operating within this 30-day Action of the Limititing Condition for.0peration.
The requested exemption would permit the licensee to return to service the now isolated PCRM utilizing the existing isolation design configuration and would allow the licensee sufficient time to design, procure, .and install necessary isolation features to achieve full compliance with the provisions of !
I Environniental Impact of the Proposed Action:
The only possible environmental impact due to this proposed action could be from increased leakage from the containment to the environment following an accident which damaged nuclear fuel in the core and pressurized the containment. l The applicable requirement for the PCRM line penetrating containment specifies a configuration consisting of two sets of automatic containment isolation valves (the existing design has one set of automatic isolation valves), which receive isolation signals from diverse sources (i.e. , high drywell pressure and reactor coolant water level.) To be in full compliance with GDC 56 requirements, the
! licensee has committed to modify the existing PCRM to incorporate two sets of l
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, i automatic isolation valves and amend the plant Technical Specifications to include these valves. These actions will be complete ( , trier to startup j 1
following the scheduled March 1988 LLRT outage. Any environmental impact associated with this proposed exemption could occur only during the interval ,
that the exemption would be in effect; i.e., about five months. During the exemption period, the licensee has committed to implement several compensatory actions which provide assurance that the PCRM will be properly isolated when required in the unlikely event of an incident requiring containment isolation.
The licensee will, while the exemption is in effect, maintain plant operating procedures that require operator action to verify the isolation of the automatic containment isolation valves and to actuate the remote-manual isolation-valves l to isolate the PCRM in the event containment isolation is required Each of the l automatic and manually operated valves will be leak-tested at least every 30 days without regsta to the 18-month test period specified in the plant Technical Specifications. Instrument channel functional tests, logic systems, valve response times and valve stroke testing will be performed in conjunction with the leak-rate tests at least every 30 days. Furthermore, the licensee will visually inspect the PCRM valves and piping for leakage, piping deformation, or other abnoi',alities on a daily basis for the duration of the exemption period.
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.. -6' Based on these considerations, the Commission has determined that.the 4
compensatory. actions committed'to by.the licensee should provide a level of isolation similar to that intended by GDC 56 and that there..is reasonable <
assurance of containment integrity in event of an acciden't requiring :)
containment isolation. Further, the Commission finds that' the' probability'of any acciden't will not be increased by permitting'the exemption requested by the-licensee,.and any post-accident radiological. releases from containment would not be greater than'previously determined. The exemption does not.otherwise affect-other radiological plant effluents. Therefore, the-Commission concludes that- j l
there are no significant radiological environmental. impacts associated with the j q
proposed exemption. 1
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With regard to potential nonradiological impacts, the proposed exemption involves systems located entirely within the-restricted area as defined in 10 'l CFR Part 20. It does not affect nonradiological plant effluents and has n'.o other environmental impact. Therefore, the Commission concludes that there are no signit! cant adverse nonradiological environmental 'mpacts i associated-with the proposed exemption.
Alternative to the Proposed Action:
Since the Commission has concluded that there is no measurable environ-i mental impact associated with the proposed exemption, any alternative to the exemption would have either no impact or a greater environmental impact.
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4 The principal alternative would be to deny the requested exemption. This would not reduce the environmental impacts of plant operation. Further, without the requested exemption, the licensee would be required to shut down I
the presently operating facility as a. result of the requirement'to maintain an
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operable PCRM as required by plant' Technical Specifications. A considerab,le delay also would be incurred as a result of the time required to design, -
procure, and install the plant modification to achieve full compliance with GDC 56 requirements. This delay would impose a significant economic impact on l
the facility without the benefit of any significant' increase ir safety. !
l Alternative Use of Resources:
The action in the granting of this exemption does not involve the'use.of resources not previously considered in connection with the " Final Environmental Statement related to the Operation of Enrico Fermi Power Plant, i Unit No. 2", (NUREG-0769) dated August 1981. {
Agencies and Persons Consulted:
The Commission's staff reviewed the licensee's request and did not consult other agencies or persons.
FINDINC OF NO SIGNIFICANT IMPACT ,
The Commission has determined not to prepare an environmental impact j i
statement for the proposed exemption. l Based upon the foregoing environmental assessment, the Commission concludes that the requested action will not have a significant effect on the quality of the human environment. j i
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For further details with respect to this. action,'see the request for exemption dated October 27, 1987, as supplemented October 29, 1987, and November 2;-1987, which is available.for public inspection at the' Commission's Public Document Room, 1717 H Street, N.W.,' Washington, D.C.
20555 and at the Monroe County Public Library System, 3700 South Custer Road, Monroe, Michigan j 48226.
Dated at Bethesda, Maryland,- this' 5th day of November,1987.
FOR THE NUCLEAR REGULATORY COMMISSION u
Martin Vi gilio, Director ,
Project Directorate III-1 l Division of Reactor Projects - III, IV, V i
& Special Projects l Office of Nuclear Reactor. Regulation i
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