ML20211K020

Exemption from Requirements of 10CFR50.47 Re Emergency Plans.Exemption Granted

ML20211K020
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	08/31/1999
From:	Zwolinski J NRC (Affiliation Not Assigned)
To:	COMMONWEALTH EDISON CO.
Shared Package
ML20211J975	List: ML20211J970 ML20211K020 ML20211K040
References
NUDOCS 9909070087
Download: ML20211K020 (5)

Text

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7590-01-P -

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION in the Matter of )

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COMMONWEALTH EDISON COMPANY ) Docket Nos. 50-295 and 50-304

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(Zion Nuclear Power Station, Units 1 and 2) )

EXEMPTION 1.

Commonwealth Edison Company (Comed or the licensee) is the holder of Facility

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Operating License Nos. DPR-39 and DPR-48, which authorize the licensee to possess the Zion Nuclear Power Station (ZNPS). The license states, among other things, that the facility is subject to all the rules, regulations, and orders of the U.S. Nuclear Regulatory Commission (the Commission or NRC) now or hereafter in effect. The facility consists of two pressurized-water reactors located at the Comed site on the west shore of Lake Michigan about 40 miles north of Chicago, Illinois, in the extreme eastern portion of the city of Zion, Illinois (Lake County). The facility is permanently shut down and defueled, and the licensee is no longer authorized to operate or place fuelin the reactor.

11. .

Section 50.12(a) of 10 CFR, " Specific exemption," states that..

The Commission may, upon application by any interested person, or upon its own initiative, grant exemptions from the requirements of the regulations of this part, whhh are: (1) Authorized by law, will not present an undue risk to the public health and safety, and are 9909070087 990831 hDR ADOCK 05000295 PDR

consistent with the common defense and security. (2) The Commission will not consider granting an exemption unless special circumstances are present.

Section 50.12(a)(2)(ii) of 10 CFR states that special circumstances are present when

" Application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule...." The underlying purpose of Sections 50.47(b) and 50.47(c)(2) is to ensure that there is reasonable assurance that adequate protective measures can and v.;;l be taken in the event of a radiological emergency, to establish plume exposure and ingestion pathway emergency planning zones for nuclear power plants, and to ensure that licensees maintain effective offsite and onsite emergency plans.

By letter dated April 13,1999, Comed requested an exemption from certain provisions of 10 CFR 50.47(b) and 10 CFR 50.47(c)(2) on the basis that the permanently shutdown and defueled condition of the ZNPS had substantially reduced the risk to public health and safety, in addition, the licensee submitted a proposed Defueled Station Emergency Plan (DSEP) for NRC's approval. The DSEP proposed to discontinue offsite emergency planning activities and to reduce the scope of onsite emergency planning. Thus, exemptions from certain provisions of 10 CFR 50.47(b) and 50.47(c)(2) are required to implement the proposed DSEP to maintain compliance with the regulation.

By letter dated April 13,1999, and supplemental letters dated July 8, July 19, and August 30,1999, the licensee also submitted an analysis of the radiological consequences of a postulated event, an analysis to determine the maximum Zircaloy cladding temperature in the spent fuel pool (SFP) with the fuel exposed to an air environment, and an analysis to determine the potential upper limit radiation fields at the exclusion area boundary.

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111.

The licensee stated that special circumstances exist at ZNPS because of the station's l

permanently shutdown and defueled condition. The standards in 10 CFR 50.47(b) and the  !

requirements in 10 CFR 5037(c)(2) were developed taking into consideration the risks associated with operation of a nuclear power reactor at its licensed full-power level. The risks include the potential for an accident with offsite radiological dose consequences. There are no design basis accidents or other credible events for ZNPS that would result in a radiological dose beyond the exclusion area boundary that would exceed the Environmental Protection Agency's (EPA) Protective Action Guidelines (PAGs). Therefore, the application of all of the standards in 10 CFR 50.47(b) and the requirements of 10 CFR 50.47(c)(2) are not necessary to achieve the underlying purpose of those rules.

The licensee analyzed the heatup characteristics of the spent fuel from a beyond design basis event that sesults in the complete loss of spent fuel pool (SFP) water, when cooling depends on the natural circulation of air through the spent fuel racks. The licensee presented the results of an analysis showing that as of June 30,1999, decay heat could not heat the 1

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spent fuel cladding above 482*C in the event all water was drained from the SFP. The staff reviewed the licensee's analysis and found the licensee's value for peak fuel cladding  !

temperature acceptable. On the basis of a staff determination that fuel cladding will remain intact at this temperature, the staff concluded that a complete loss of water from the ZNPS SFP -

would not result in a release off site that exceeds the early-phase EPA PAGs.

Although a significant release of radioactive material from the spent fuel is no longer possible in the absence of water cooling, a potential exists for radiation exposure to an offsite individual in the event that shielding of the fuel is lost (a beyond-design-basis event). Water '

and the concrete pool structure serve as radiation shielding on the sides of the pool. However,

water alone provides most of the shielding above the spent fuel. A loss of shielding above the fuel could increase the radiation levels off site because of the gamma rays streaming up out of the pool being scattered back to a receptor at the site boundary. The licensee calculated the offsite radiologicalimpact of a postulated complete loss of SFP water and determined that the gamma radiation dose rate at the exclusion area boundary would be 0.00294 ' rad per hour at an outside air temperature of 21 *C. At this rate, it would take 14 days for the event to exceed the 1

EPA early phase PAG c'1 rem. The EPA early-phase PAG is defined as the period beginning l l

at the projected or actualinitiation of a release and extending a few days later. The PAGs were developed to respond to a mobile airborne plume that could transport and deposit radioactive i material over a large area. In contrast, the radiation field formed by scatter from a drained SFP would be stationary rather than moving and would not cause transport or deposition of I radioactive materials. The 14 days available for action allow sufficient time to develop and  ;

implement mitigative actions and provide confidence that additional offsite raeasures could be taken without planning if efforts to reestablish shielding over the fuel are delayed. '

The standards and requirements that remain in effect are listed in Attachment 1 to the licensee's letter of April 13,1999, and Attachment 2 to the licensee's letter of July 8,1999. On the basis of this review, the staff finds that the radiological consequences of accidents possible I

at ZNPS are substantially lower than those at an operating plant. The upper bound of offsite dose consequences limits the highest attainable emergency class to the alert level. In addition, because of the reduced consequences of radiological events still possible at the site, the scope of the onsite emergency preparedness organization may be reduced. Thus, the underlying purpose of the regulations will not be adversely affected by eliminating offsite emergency planning activities or reducing the scope of onsite emergency planning. Accordingly, the

4 Commission has determined that special circumstances as defined in 10 CFR 50.12(a)(2)(ii) exist.

IV.

The Commission has determined that, pursuant to 10 CFR 50.12, the exemption is authorized by law, will not present an undue risk to the public health aisd safety and is consistent with the common defense and security, and is otherwise in the public interest.

Therefore, the Commission hereby grants Commonwealth Edison Company an exemption from l certain requirements of 10 CFR 50.47(b) and 10 CFR 50.47(c)(2).

l Pursuant to 10 CFR 51.32, the Commission has determined that granting of this exemption will have no significant impact on the environment (64 FR 45981).

This exemption is effective upon issuance.

f FOR THE NUCLEAR REGUl>> ORY COMMISSIOtJ 1

Joh A. Zwolinski, Director Division of Licensing Project Management Office of Nuclear Reactor Regulation Dated at Rockville, Maryland, this 31st day of August 1999

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