ML20133P802

Exemption from 10CFR50 App A,Gdc 34 Re RHR Sys & GDC 37 Re Testing of ECCS Sys

ML20133P802
Person / Time
Site:	Three Mile Island
Issue date:	08/08/1985
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	GENERAL PUBLIC UTILITIES CORP.
Shared Package
ML20133P766	List: ML20133P765 ML20133P771 ML20133P785 ML20133P802 ML20133P830
References
NUDOCS 8508140490
Download: ML20133P802 (5)

Text

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Enclosure 4 UNITED STATES NUCLEAR REGULATORY C0fetISSI,0N In the Matter of GENERAL PUBLIC UTILITIES NUCLEAR ) Docket No. 50-320

' CORPORATION ,

! (Three Mile Island Nuclear Station

! Unit 2) -

l EXEMP IONS I.

! GPU Nuclear Corporation, Metropolitan Edison Company, Jersey Central Power I

and Light Company and Pennsylvania Electric Company (collectively, the .

i licensee) are the holders of Facility Operating License No. DPR-73, which has authorized operation of the Three Mile Island Nuclear Station, Unit 2 (TMI-2) at power levels up to 2772 megawatts thermal. The facility, which is located in Londonderry Township, Dauphin County, Pennsylvania, is a pressurized water reactor previously used for the commercial generation of electricity.

b 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 i shutdowncoolingmode(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 f

(45 Fed. Reg.11292). This license provides, among other things, that it

) is subject to all rules, regulations and Orders of the Commission now or i

hereafter in effect. -

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II.

On November 6,1984, General Public Utilities Nuclear Corporation (GPUNC) submitted Technical Specification Change Request No. 46. This corres-pondence contained a request to delete the Decay Heat Removal System from the THI-2 Proposed Technical Specifications. The staff responded to this and other change requests with a list of questions forwarded on February 6, 1985. The licensee was asked to consider whether exemptions from 10CFR50,AppendixA,GeneralDesignCriteria(GDC) 34, 35, 36 and 37 were o appropriate. GPUNC responded in correspondence dated March 27, 1985 which stated that exemptions from GDC 35 and 36 were not required. However, an exemption request from GDC 34 and 37 was requested by GPUNC in a letter dated March 26, 1985. The staff is issuing the requested exemptions as discussed herein.

III.

10 CFR 50, Appendix A, GDC 34 requires that a system to remove residual heat shall be provided. The purpose shall be to transfer' fission product decay heat and other residual heat from the core at such a rate that acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded.

Since January 1981, the THI-2 core has been cooled passively via the loss-to-ambient mode. At present the decay heat level is less than 12 Kw thernal with an associated maximum core temperature of less than 100*F.

. The maximum temperature that is credible while in this mode (no forced circulation) is less than 170*F assuming water level is lowered to the

c. .. . . .. . .

bottom o# the hot leg nozzles. At this temperature sufficient buffer is still maintained between the maximum anticipated core temperature and the temperature at which the water in the vessel would boil (212*F). There-fore, the staff concludes that since the current loss-to-ambient mode is ,.

effective for all anticipated core temperatures, the requirement to have a

. residual heat removal system (GDC 34) is no longer necessary at TMI-2. On the other hand, portions of the residual heat removal system at TMI-2 still contain radioactive contamination resulting from the accident. Operation of the system could result in the spread of radioactive contamination. In addition, the requirement to maintain an operable residual heat removal system would result in an unnecessary burden for maintenance, surveillance and testing and could result in unnecessary radiation exposures to the workers. Accordingly, an exemption for GDC 34 is warranted.

The licensee has proposed in Technical Specification Change Request No. 46 that a Reactor Building Sump Recirculation System (RBSRS) be used for emergency core cooling at THI-2. The system would only be installed in the event of an unisolable leak in the RCS. Licensee calculations, which are supported by the staff in an Amendment of Order concurrently issued with this exemption, conclude that at least 10 days are available between the detection of the worst-case credible leak and when the RBSRS would be required. This gives ample time for the system to be put in service. As stated in the referenced Amendment of Order, the staff has accepted the RBSRS and its proposed method of use. This acceptance included Recovery Operations Plan requirements for testing the operability of major system

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r components on a regular basis (see the staff's Safety Evaluation Report dpproving the modifications to the Proposed Technical Specifications related to Borated Cooling Water Injection). GDC 37 requires the testing of the emergency core cooling system including the operability of the system as a whole and the performance of the full operational sequence.

Since the staff has accepted tne installation of the RBSRS in the reactor building only in the event of an unisolable leak in the RCS, the testing of' the system according to GDC 37 is not necessary. In addition, since the reactor building basement still contains accident generated contaminated water, testing of a basement sump recirculation system in a full operational sequence could result in the spread of contamination and radiation exposures to the workers. Accordingly, an exemption from GDC 37 is warranted.

IV.

Accordingly, the Comission has determined that, pursuant to 10 CFR 50.12, an exemption is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest.

The Comission hereby grants exemptions from the requirements of 10 CFR 50, Appendix A General Design Criteria 34 and 37 in accordance with the licensee's request dated March 26, 1985.

} It is further determined that the exemptions do not authorize a change in effluent types or total amounts nor an increase in power level and will not rcsult in any significant environmental. impact. In light of this deter-mination and as reflected in the Environmental Assessment and Notice of

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• l Finding of No Significant Environmental Impact prepared pursuant t'o 10 CFR I

51.2 and 51.30 through 51.32, issued concurrently herewith, it was con-cluded that the instant action is insignificant from the standpoint of environmental impact and an environmental impact statement need not be prepared.

FOR THE NUCLEAR REGULATORY COWilSSION l k Harold R. Denton, Director Office of Nuclear Reactor Regulation

- Effective Date: September 23, 1985 Dated at Bethesda, Maryland Issuance Date: August 8, 1985 ,

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