ML20210D729

Exemption from Requirements of 10CFR70.24 Re Criticality Accident Requirements for SNM Storage Areas at Facility Containing U Enriched to Less than 3% in U-235 Isotope

ML20210D729
Person / Time
Site:	Three Mile Island
Issue date:	06/15/1992
From:	Boger B Office of Nuclear Reactor Regulation
To:	GENERAL PUBLIC UTILITIES CORP.
Shared Package
ML20210D728	List: ML20210D723 ML20210D729 ML20210D733
References
NUDOCS 9206180011
Download: ML20210D729 (4)

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y, 1 4 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of- )

)

GENERAL PUBLIC UTILITIES )

NUCLEAR CORPORATION ) Docket No. 50-320

)

(Three Mlle Island Nuclear )

Station, Unit 2) )

EXEMPTION _

I GPU Nuclear Corporation, (the licensee) is the holder of Facility Operating License No. DPR-73, which had authorized the operation of the Three Mile Island Nuclear Station, Unit 2 (TMI-2) at power levei, up to 1

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.

By Order for Modification of License, dated July 20, 1979, the licensee's authority to operate the facility was suspended and the !icensee's authority b was limited to maintaining the facility in the shutdown cooling mode (44 FR 45271). By further Ordar of the Director, Office of Nuclear Reactor Regulation, dated February 11, 1980, a new set of formal license reqairements was imposed to reflect the post-accident condition of the facility and to assure the conMnued maintenance of the safe, stable, long-term cooling condition of the facility (45 FR 11292). These license conditions and those imposed by subsequent orders were formally incorporated into the TMI-2 lics.

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on January 27, 1987. The license provides, among other things, that it is subject to all_ rules, regulations and orders of the Commission now or hereafter in-effect.

11 Section (a) of 10 CFR 70.24 requires that each licensee authorized to possess special nuclear material (SNM) shall maintain in each area where such material is handled, used, or stored, an' appropriate criticality monitoring system. Section (a)(1) of 10 CFR 70.24 requires that covcrage of all such areas at TMI-2 shall be provided by two criticality detectors.

By letter dated May 21, 1987, GPU Nuclear requested an exemption from

.this requirement for TMI-2 SNM sample storage areas. Specifically,the licensee proposed to handle and store SNM samples without having the two criticality monitoring systems required by 10 CFR 70.24. Such exemptions may be authorized pursuant to 10 CFR 70.24, provided that the licensee has shown that good cause exists for the exemption. In particular, Revision 2 of

-Regulatory Guide 8.12 " Criticality Accident Alarm Systems," October 1988, states that it is appropriate to request an exemption from 10 CFR 70.24 if an evaluation determines that a potential for criticality does not exist, as for example Wnere the quantities or form of special nuclear material make criti-cslity practically impossible or where geometric spacing is used to preclude criticality.

The licensee has previously demonstrated in "Ex-RCS Criticality Safety" TP0/TMI-132,- November 1985,.that the minimum critical mass has been conserva-tively calculated to be 93 Kg for the maximally enriched fuel used at

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.TM1-2. The NRC staff has confirmed the licensee's evaluation. This has been documented most recently in the staff's " Technical Evaluation of THI-2 Post-Defueling Monitored Storage," February 1992. The licensee has applied an additional 25 percent mass conservatism and derived an administrative safe fuel mass limit of 70 Kg. The licensee proposes to limit storage of SNM in any storage area to less than 70 Kg and to use criticality safe storage containers for all storage of wiM. Additionally, the licensee has placed geometric limits requiring a minimum separation distance of either 12 feet of r air or 1 foot of concrete between SNM storage areas. The NRC staff finds this 4 acceptable. The limitations on spacing of adjacent SNM storage areas will preclude neutronic interaction between any of the storage areas. The staff has also required that all storage containers be criticality safe by design.

Since the stored SNM will be criticality safe by the use of mass limits and geometric spacing, we conclude that the licensee's request for and exemption from the requirements of 10 CFR 70.24 with respect to storage of SNM samples is acceptable and should be granted. -

111 Accordingly, the Commission has determined that pursuant to 10 CFR 70.24(d) good cause exists for the granting of this exenption, in accordance with 10 CFR 70.14 exemption from the requirements of 10 CFR 70.24 is authorized by law and granting the exemption will not endanger life or property or the common defense and security, and is in the public interest.

Accordingly, the Commission hereby grants enmption from the requirements of 10 CFR 70.24, criticality accident requirements for SNM storage areas at l

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4 Three Mile Island, Unit 2. Pursuant to 10 CFR 51.32, the Corrsission has determined that the granting of this exemption will have no significant impact on the quality. of the human environment (57 FR 26668, June 15,1992).

FOR THE NUCLEAR REGULATORY COMMSSION

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Bruce A. Boger, Di ector _

Divition of Reactor Projects - III/lV/V Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 15th day of June 1992.

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