ML20204G167
| ML20204G167 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 07/30/1986 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | DETROIT EDISON CO. |
| Shared Package | |
| ML20204G171 | List: |
| References | |
| NUDOCS 8608070092 | |
| Download: ML20204G167 (7) | |
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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DETROIT EDISON COMPANY l
WOLVERINE POWER SUPPLY COOPERATIVE,
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Docket No.50-34I INCORPORATED
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(Fermi-?)
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EXEMPTION I.
Detroit Edison Company (DECO or the licensee) is the holder of Facility Operating License No. NPF-43 which authorizes the operation of the Fermi-?
facility at steady-state power levels not in excess of 3292 megawatts thermal.
The license provides, among other things, that the facility is subject to all rules, regulations and Orders of the Nuclear Regulatory Comission (the Commission) now or hereafter in effect.
The facility is a boiling water reactor (BWR) located at the licensee's site in Monroe County, Michigan.
II.
The Femi-2 facility achieved its initial criticality on June 21, 1985.
In compliance with the applicable requirements of Section 50.44 of 10 CFR Part 50, the primary containment of this facility, which has a toiling light-water nuclear power reactor with a Mark I type containment, was required to be inerted by December 21, 1985. The purpose of this regulatory requirement is to provide protection against hydrogen burning and explosions which might occur were gaseous hydrogen to be generated in the event of a loss-of-coolant accident. Due to an incident on, July 1-2, 1985, involving errors in reactivity control, the NRC issued a Confimatory Action Letter (CAL) on July 16, 1985, limiting the Femi-2,
facility to operations at a power level not exceeding five percent of rated The facility operated at this power level from then until October 11, power.
1985, when it was shutdown to install certain pieces of equipment.
No o 700h xie
. Due to a number of other problems, including a failure of a main bearina of an emergency diesel generator, the plant has remained shutdown and is not expected to restart until late July 1986, at the earliest.
Accordinaly, the licensee has been unable to proceed with, and complete, its Startup Test Program (STP) as originally planned during the initial six-month period following issuance on March 20, 1985, of the low-power Fermi-2 operating license, NPF-33. More importantly, the licensee was not able to con-duct its STP within the six-month period during which the containment need not be inerted (i.e., June 21, 1985, to December 21,1985) in accordance with 10 CFR 50.44.
In light of this restriction on power level and the delay resul. ting from the scheduled shutdown in early October 1985, the licensee requested an exemption, for a limited period of time, from the requirement to inert the primary contain-ment. This request was contained in its letter dated October 9, 1985, and supplemented in its letter dated November 13, 1985. This temporary exemption would permit the licensee to continue operating the Fermi-2 facility with a non-inerted containment during the balance of the initial startup test program as originally planned.
III.
In its request for the subject exemption, the licensee requests an exemption from the requirement of Section 50.44(c)(3)(1) to allow completion of the startup test program with a non-inerted containment. The actual time limit proposed in the requested exemption is the end of the Startup Test Program, described in
. Chapter 14 of the FSAR, or until the reactor core has operated for 120 effective full power days, whichever is earlier. The end of the startup test phase is determined by the completion of the 100 percent rated thermal power trip tests. -
The licensee's Startup Test Program is based on maintaining the primary containment in a non-inerted condition; 1.e., not removing the oxygen contained in normal air from the containment by purging with nitrogen. Completion of the Startup Test Program would normally be expected to occur within about 120 effec-tive full power days (e.o., within 6 months at an average power level of about 70 percentl. Based on this consideration, the licensee's reauest for an exemp-tion will not result in a significant change, if any, in the maximum full power days of reactor core burnup which would have been accumulated had the licensee been able to conduct its startup program without any extended delays or without a restriction on power level.
The reason the licensee has proposed a maximum fuel burnup of 120 effective full power days (EFPD), as noted above, was to assure that the buildup of the fission product inventory will be limited during the :tartup test phase. This limitation on the fission product inventory will minimize.the risk to public health and safety in two ways. First, the limit on the fission product inventory will put an upper limit on the amount of decay heat in the reactor core which would have to be removed in the event of a loss-of-coolant accident (LOCA). This in turn will limit the potential rise in fuel clad temperature following a post-ulated LOCA. It is the value of this last parameter which determines whether there would be a fuel clad failure leading to the release of the radioactive fission products. Thus, the limit on the effective full power days proposed by the licensee will serve to minimize the probability of the release of radio-
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. activity to the environment in the event of a 1.0CA as well as limit the amount of radioactivity which was available for release. Secondly, the proposed limit on the integrated power history will minimize the fission product inventory in th7 fuel which could be released through other postulated accident scenarios such as the dropped rod accident. The NRC staff finds for these reasons, dis-cussed above, that the level of safety provided by the proposed limited inerting exemption will not be significantly reduced, if at all, from that margin of safety implicit in the 6-month inerting exception in 10 CFR 50.44(c)(3)(1) to inerting requirements.
Since the startup tests will be perfomed in essentially the same manner as originally planned with respect to the magnitude and duration of power levels for these tests, the NRC staff concludes that there will be no increase in the risks of operating the Femi-2 facility during the startup tests with the pro-posed limited exemption over those risks which were contemplated by the staff when the Fermi-2 facility was granted its operating license. Therefore, since there is no increase in risk caused by the mere fact of extending the time allowed for conducting the startup tests while not inerted, the NRC staff finds that operating the Femi-2 facility during the startup test phase will be as safe under the conditions proposed for the exemption as operations would have been had the startup tests been completed in the Six-month period after initial criticality.
There is also a positive benefit in operating the reactor without inerting the containment during the startup test phase becatse this condition would pemit frequent inspections and/or the identification of potential problems which might affect safety during this period, without incurring the delay 9ssociated with deinerting and reinerting the containment. The anticipated high frequency of j
. containment entries by plant personnel during the startup tests, together with the 24-hour periods required to deinert and reinert, would tend to discourage prompt and frequent containment entries to identify and correct any potential safety problems before they could become serious safety problems. In this regard, frequent containment entries are nomally required during the startup test phase to adjust control systems, calibrate instruments and monitor contain-ment conditions as the plant ascends in power. Were the requested exemption rot to be granted, there would be a considerable delay in the overall startup test phase which would thereby delay the start of consnercial operation of the Femi-2 facility.
Accordinoly, based on the foregoing discussion, the staff finds that the proposed exemption poses no increase in risk to public health and safety, and is consistent with the intent of 10 CFR 50.44 regarding containment inerting. The staff also finds that granting the proposed exemption will promote the efficient and expeditious testino of the Femi-2 systems and components and is, therefore, in the public interest. On this basis, we find that the proposed limited exemp-tion from Section 50.44(c)(3)(1) of 10 CFR Part 50 is acceptable.
IV.
Accordingly, the Comission has determined that, pursuant to 10 CFR 50.12, this exemption is authorized by law, will not present an undue risk to the public health and safety, and is consistent with the consnon defense and security. The Commission further detemines that special circumstances, as provided in 10 CFR 50.12(a)(2)(iii), are present justifying the exemption; namely, that application of the regulation in the particular circumstances would result in undue hardship and other costs which are significantly in excess of those contemplated when the
. regulation was adopted and that are significantly in excess of those incurred by others similarly situated. If the licensee were forced to inert the containment prior to completing the startup test phase solely to comply with Section 50.44(c)(3)(1) of 10 CFR Part 50, an undue hardship and financial burden would result from the delay in comercial operation of the Femi-2 facility caused by the need to deinert and reinert each time entry into the containment is required.
The costs would be significantly in excess of those contemplated when the subject regulation was adopted in that the staff believed the startup test phase could be accomplished within six months of initial criticality withcut the need to deinert and reinert for each containment entry. The cost and hardship imposed on the licensee by failing to grant the proposed exemption would be considerably in excess of that contemplated when the rule was adopted. Therefore, the Com-mission hereby approves the following exemption request:
With respect to the requirement to provide an inerted atmosphere for the Femi-2 Mark I containment no later than December 21, 1985, pursuant to Section 50.44(c)(3)(1) of 10 CFR Part 50, exemption is granted from this provision for a limited period not extending beyond the completion of the lO percent rated themal power trip tests or i
until the reactor has operated for 120 effective full power days, whichever is earlier.
l The Comission has further determined that the exemption does not authorize a change in effluent types or total amounts of effluents nor an increase in power level and will not result in any significant environmental impact. In light of this detemiaation and as reflected in the Notice of Environmental Assessment and' Finding of No Significant Impact prepared pursu nt to 10 CFR 51.2 and 51.30 l
. through 51.32, it is concluded that the instant action is insignificant from the standpoint of environmental irapact and an environmental impact statement need not be prepared.
For further details with respect to this action, see the licensee's request dated October 11, 1985, and supplemented on November 13, 1985, which are 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 Library System, 3700 South Custer Road, Monroe, Michigan 48161.
Pursuant to 10 CFR 51.32, the Commission has determined that the granting of this Exemption will have no significant impact on the environment (51 FR 26315 dated July 22,1986).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION W
Gus Lainas, Acting Director Division of BWR Licensing Office of Nuclear Reactor Regulation Dated at Betherda, Maryland this 30th day of July 1986
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