ML20210T165

Environ Assessment & Notice of Finding of No Significant Environ Impact Supporting Exemptions to 10CFR50,App A,Gdc 17 & 19 Requirements Re Electric Power Sys & Control Rooms

ML20210T165
Person / Time
Site:	Three Mile Island
Issue date:	02/03/1987
From:	Masnik M Office of Nuclear Reactor Regulation
To:
Shared Package
ML20210T117	List: ML20210T112 ML20210T152 ML20210T165
References
NUDOCS 8702180091
Download: ML20210T165 (5)

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UNITED STATES NUCLEAR REGULATORY COMMISSION b GENERAL PUBLIC UTILITIES NUCLEAR CORPORATION DOCKET NO. 50-320 ENVIRONMENTAL ASSESSMENT AND NOTICE OF FINDING OF N0 SIGNIFICANT ENVIRONMENTAL IMPACT The U.S. Nuclear Regulatory Commission (the Commission) is planning to issue two Exemptions to the requirements of 10 CFR 50, Appendix A, General Desion Criteria 17 and 19, relative to Facility Operating License No. DPR-73, issued to General Public Utilities Nuclear Corporation (the licensee), for operation of the Three Mile Island Nuclear Station Unit 2 (TMI-2), located in Londonderry Township, Dauphin County, Pennsylvania. By Order for Modification of License, dated July 20, 1979, the licensee's authority to operate the facility was suspended and the licensee's authority was limited to maintenance of the -

facility in the present shutdown cooling mode (44 Fed. Reg. 45271). By further Order of the Director, Office of Nuclear Reactor Regulation, dated February 11, ,

1980, a new set of formal license requirements was imposed to reflect the post-accident condition of the facility and to assure the continued maintenance of the current safe, stable, long-term cooling condition of the facility (45

- Fed. Reg. 11292). The license provides, among other things, that it is subject to all rules, regulations and Orders of the Commission now or hereafter in effect.

8702180091 870209 0 DR ADOCK 0500 i

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• h, ENVIRONMENTAL ASSESSMENT I

Identification of Proposed Action: The actions being considered by the Commission are exemptions from 10 CFR 50, Appendix A, General Design Criteria (GDC) 17 and 19 relating to requirements for electric power systems and nuclear station control rooms. Specifically, GDC 17 requires that an onsite and offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. As relevant to the licensee's request, GDC 19 requires that a control room shall be provided from

, which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions. GDC 19 further requires that radiation protection shall be '

provided to permit access and occupancy of the control room under accident conditions, within specified exposure limits.

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The Need for the Proposed Action: TMI-2 is currently in a post-accident, cold shutdown, long-term recovery mode, with sufficient decay beat removal assured by direct heat loss from the reactor coolant system (RCS) to the reactor buiidingatmosphere. In case of a TPI-2 loss of coolant event, sufficient l borated makeup water will be provided by a passive gravity feed system to maintain the level of the RCS above the damaged fuel for a minimum of 10 days.

Dedicated equipment is available and procedures have been established to provide recirculation to assure long-term core coverage, if necessary, even in the unlikely event that the Unit 2 control room is temporarily uninhabitable.

Consequently, the facility can be maintained for the short term in a safe,

.- stable shutdown condition without relying upon action from control boom-personnel and continuous manning of the THI-2 control room is not n4cessary under worst-case accident conditions to achieve the underlying purpose of the requirement. For.this reason, a_ partial exemption to the reouirenents of GDC 19 is justified.

Since continuous control room manning is no longer necessary for all postulated events, with TMI-2 in its current long-term cold shutdown mode, control room emergency air cleanup system operability does not have to be continuously maintained. Therefore, onsite emergency backup power provided by the diesel generators is not needed for the system. This removes the need for the last load on the diesel generators still required by the facility license, and safe shutdown of the plant is no longer dependent on the onsite backup emergency power source. Thus, the performance of maintenance and surveillance of the emergency diesel generators required by GDC 17 would impose an unnecessary burden and expense on the licensee with no concomitant benefit in terms of '

achieving the underlying purpose of the requirement.

, Environmental Impact of the Proposed Action: The staff has evaluated the subject exemptions and concludes that in light of the current and future condition of the facility described above, there are no significant radio-logical or nonradiological impacts to the environment as a result of this action. The exemptions remove specific features of the Commission's require-ments to provide an onsite electric power system and a control room to maintain the nuclear power unit in a safe condition following an accident.

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-4 Alternatives to the Proposed Action: SincetheCommissionhasconckudedthat there is no significant environmental impact associated with the proposed exemptions, any alternatives to this action will have either no significant

. environmental impact or greater environmental impact. This would not reduce significant. environmental impacts of plant operations and would result in the application of unnecessary regulatory requirements.

' Agencies and Persons Consulted: The NRC staff reviewed the licensee's reauest and did not consult other agencies or persons.

Alternative tise of Rescurces: This action does not involve the use of resources not previously considered in connection with the Final Programmatic Environmental Impact Statement for TMI-2, dated March 1981.

FINDING OF NO SIGNIFICANT IMPACT The Commission has determined not to prepare an environmental impact statement for the proposed exemptions. Based upon the foregoing environmental assessment, we conclude that this action will not have a significant effect on the quality of the human environment.

For further details with respect to this action see: (1) letter from F. R. Standerfer, GPUNC to W. D. Travers, USNRC, Exemption from 10 CFR 50 Appendix A, General Design Criteria 17 and 19, dated December 10, 1986. This document is available for inspection at the Commission's Local Public Document

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-5 Room,1717 H. Street, N.W. , Washington, D.C., and at the Conunission'I. Local Public Document Room at the State Library of Pennsylvania, Government Publications Section, Education Building, Conunonwealth and Walnut Streets, Harrisburg,-Pennsylvania 17126.

Dated at Bethesda, Maryland, this 3rd day of February 1987. 1 FOR fHE NUCLEAR REGULATORY COP' MISSION h fc==

Michael T. Masnik, Acting Director TMI-2 Cleanur Pro,iect Directorate Office of Nuclear Reactor Regulation i

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