ML17055E156
| ML17055E156 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/06/1988 |
| From: | Capra R Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17055E157 | List: |
| References | |
| NUDOCS 8809130336 | |
| Download: ML17055E156 (10) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION NIAGARA MOHAWK POWER CORPORATION NINE MILE POINT NUCLEAR STATION, UNIT 1 DOCKET NO. 50-220 NOTICE OF ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT 7590-01 The U.S. Nuclear Regulatory Commission (the Commission) is considering issuing an exemption from certain requirements of 10 CFR Part 50, Appendix J, to the Niagara Mohawk Power Corporation (the licensee), for the Nine Mile Point Nuclear Station, Unit 1 (NMP-l), located at the licensee's site in Scriba, New York.
ENVIRONMENTAL ASSESSMENT Identification of Pro osed Action:
The proposed action would exempt the licensee from meeting certain requirements of 10 CFR 50, Appendix J, until startup following the next refueling outage.
Appendix J requires containment isolation valves to be Type C leakage tested.
In the past the licensee has not included the four containment isolation valves in the condensate return lines from the emergency condensers (39-03, -04, -05, -06) in the Type C testing program.
The licensee did not consider them to be containment isolation valves.
- However, by letter dated May 6, 1988 the NRC transmitted to the licensee a safety evaluation (SE) concerning the licensee's leakage rate testing program.
In that SE the staff stated its finding that the subject valves needed to be included in the Type C testing program.
These valves, particularly the inside check valves which were designed to be held closed by high reactor water pressure (1000 psig) rather than Type C air pressure (35 psig), were not designed to meet the criteria of the Appendix J, Type C leak test.
Consequently, these valves have been unable to pass the Type C leakage criteria.
8809130336 880906 PDR ADOCK 05000220 PDC j)
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The licensee has proposed that a schedular exemption be granted from the requirement to perform Type C leakage testing of the emergency condenser condensate return line valves (39-03, -04, -05, and -06) and from the requirement that the leakage of these valves be included in the 0.60L acceptance criteria a
for Type 8 and Type C tests.
The requested exemption is for the period up to and including the next refueling outage.
The schedular exemption was requested to allow time to procure needed hardware and to develop and install the necessary changes to meet the requirement of 10 CFR 50, Appendix J.
The licensee's request for this exemption, and the basis therefor are contained in its letter dated June 23, 1988.
The Need for the Pro osed Action:
The exemption is required in order to permit the licensee to star tup from the current outage and operate the plant while the necessary changes are developed and the necessary hardware is procured.
The licensee has estimated the development, procurement, and installation of the required changes may take 18 to 24 months.
Mithout this exemption the restart and operation of this plant would be delayed until the necessary changes and testing were completed.
Environmental Im act of the Pro osed Action:
The exemption would allow the changes needed to the isolation valves on the emergency condenser condensate return lines to meet the requirements of 10 CFR, Appendix J, to be completed during the next refueling outage.
The exemption would allow the plant to be operated during the period of 'time necessary to determine the necessary changes and procure the necessary hardware.
The licensee has stated that the effects of a design basis loss-of-coolant accident (LOCA) involving emergency condenser tubing with the condensate return line valves leaking beyond Appendix J limits are bounded by the existing LOCA analysis in the Final Safety Analysis Report (FSAR).
Furthermore, the failure
of the subject valves to meet Appendix J leakage limits will not increase the probability of uncovery of or damage to the fuel, or failure of accident mitigation systems such as the emergency core cooling system (ECCS).
The requested exemption will not affect normal radiological plant effluents nor increase normal occupational exposure.
The emergency condenser system will automatically isolate in the event system integrity is significantly compromised.
In addition, the subject valves are normally closed during normal plant operation.
If the leakage in these lines exceeds 10 gpm, the leakage can be detected by steam from the condenser vent or a reactor coolant system imbalance.
If there is excessive
- leakage, the licensee has stated that the reactor will be shut down.
Furthermore, the requested exemption is for a period of one cycle (approximately 24 months).
The probability of a LOCA with system leakage outside containment during this time period is low.
Therefore, based on.the low probability of a LOCA during this time frame and the considerations discussed
- above, the staff concludes that granting the proposed exemption will not increase the probability of an accident and will not result in any post-accident radiological releases significantly in excess of those previously determined for Nine Mile Point Nuclear Station, Unit 1.
Moreover, the proposed exemption would not otherwise affect radiological plant effluents, nor result in any significant occupational exposure.
- Likewise, the exemption does not affect non-radiological plant effluents and has no other environmental impact.
Therefore,= the Commission concludes that there are no significant radiological or non-radiological environmental impacts associated with the proposed exemption.
Alternative to the Pro osed Action:
The staff has concluded that there is no measurable environmental impact associated with the proposed exemption.
Therefore, alternatives to the exemption will have either no environmental impact or greater environmental impact.
The principal alternative would be to deny the requested exemption.
Such action would not reduce the environmental impacts of the Nine Mile Point Nuclear Station, Unit 1 operations and would result in unwarranted delays in plant startup and operation.
Alternative Use of Resources:
These actions associated with the granting of the proposed exemption as detailed above do not involve the use of resources not previously considered in connection with the "Final Environmental Statement Related to Operation of Nine Mile Point Nuclear Station, Unit No. 1," dated January 1974.
A encies and Persons Consulted:
The NRC staff reviewed the licensee's submittal that supports the proposed exemption discussed above.
The NRC staff did not consult other agencies or persons.
FINDING OF NO SIGNIFICANT IMPACT The Commission has determined not to prepare an environmental impact statement for the proposed exemption.
Based upon the foregoing environmental assessment, the Commission concludes that the proposed action will not have a significant effect on the quality of the human environment.
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For further details with respect to this action, see the request for the exemption as listed herein, 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 Penfield Library, State University College,
- Oswego, New York 13126.
Dated at Rockville, Maryland, this 6th day of September 1988.
FOR THE NUCLEAR REGULATORY COMMISSION Robert A. Capra, Director Project Directorate I-1 Division of Reactor Projects I/II
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