ML20206E132

Environ Assessment & Finding of No Significant Impact Re Exemption from Requirements of 10CFR50,App J,Paragraph III.A.3 & Associated License Amend to Permit Use of Mass Point Method of Primary Containment Leakage Testing

ML20206E132
Person / Time
Site:	Millstone
Issue date:	11/14/1988
From:	Stolz J Office of Nuclear Reactor Regulation
To:
Shared Package
ML20206E115	List: ML20206E111 ML20206E132
References
NUDOCS 8811170414
Download: ML20206E132 (5)

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e 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION  ;

NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCL_ EAR POWER STATION,, UNIT NO. 3 DOCKETNO._50,,4M ENVIRONMENTAL ASSESSMENT AND FINDING OF NOSIGNIFICANTIM, pag A

The U. S. Nuclear Regulatory Comission (the Commission) is considering issuance of an exemption from the requirements of Appendix J to 10 CFR Part 50 and an associated license amendment to Northeast Nuclear Energy Company, et al.

(the licensee) for the Millstone Nuclear Station, ULit No. 3, located at the licensee's site in New London County, Connecticut.

EMYIRONFENTAL ASSESSMENT Identification of Proposed Action:

The licer.see is requesting an exemption from Paragraph III.A.3 of 10 CFR Part 50 Appendix J "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors" to permit the use of the mass-peint method of primary contairsent leakage testing. In 1973, Appendix J was issued to established requirements for primary containment leakage testing and incorporated by reference ANS! N45.4-1972, "Leakage Rate Testing of Containment Structures for Nuclear Reactors." This standard requires that containment leakage caleclations be perfomed by using either the point-to-point method or the total time method. .

At this tine, a licensee who wishes to use mass-point must submit an application for exemption from the Appendix J requirement that containrent integrated leak rate tests will conform to ANSI N45.4 The exemption proposed 8811170414 881114 DR ADOCK 0500 Q3

, -2 v by the licensee would be granted until a proposed revision to Appendix J, which will permit use of the mass-point method, becomes effective. In the mass-point ,.

method, the mass of air in containment is calculated and plotted as a function

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of time and leakage is calculated from the slope of the linear least squares.

With the present developments in technology, the mass-point method has gained increasing recognition.

The superiority of the :nass-point method becomes apparent when it is conpared with the two other methods. In the total time method, a series of leakage rates is calculated on the basis of air mass differences between an initial data point and each individual data point thereafter. If for any rewson (such ae instrurent error, lack of temperature equilibrium, ingassing or outgassing) the initial data point is not accurate, the results of the test will be affected. In the point-to-point method, the leak rates are based on the na!4 difference between each pair of consecutive points which are then averaged to yield a single leakage rate estimate. Fathen,atically, this can be shown to be the difference between the air mass at the beginning of the test and the air mass at the end of the tett expressed as a percentage of the containment air mass. It follows from the above that the point-to-point method ignores any mass readings during the test and thus the leakage rate is calculated on the basis of the difference in mass between two reasurenents taken at the beginning and at the end of the test, which are 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> apart.

The licensee's request and bases for exemption are cor)tained in a letter dated August 11, 1988.

, The licensee has also requested changes to the Technical Specifications that are related to the containment leak rate test. By arplication for license amendment dated August 11, 1988, the licensee requested changes to Millstone Unit 3 Technical Specification (TS) 4.6.1.3, "Containment Leakage " to allow for use of ANSI /AN3 Standard 56.8-1981 for "mass-point" detemination of containment leakage rate.

A "Notice of Consideration of Issuance of Amendment to Facility Operating License and Proposed No Significant Hazards Consideration Determination ar.d Opportunity for Hearing" regarding the proposed changes to TS 4.6.1.? was published in the FEDERAL REGISTER on September 21, 1988 (53 FR 36672).

The Need for,,T,he Prop,0,seQct, ion:

The exemption and associated license amendment are needed to allow use of the mass point analysis method at Millstone Unit No. 3.

Enviror. men,t,al,Jmpactsoftheoroposed Action:

The erraticism of the total time method creates a higher probability of unnecessarily failing a containment integrated leakage rate test (note that the calculational procedure is independent of containn,ent tigh+.ncss) possibly resulting in increased test frequency, critical path outage time, and exposure to test personnel.

Radiological releases will not be greater than previously detemined, nor does the proposed exemption otherwise affect r.',diological plant effluents, or have any other environmental impact. Therefore, the Comis.sion concludes that there are no measurable radiological or non-radiolostcal environmental impacts associated with the proposed exemption and associated license amendment,

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Alternatives to the Prop ged Action:

It has been concluded that tFere is no measurable impact associated with the proposed exemption and asse,ciated license amendment; any alternatives to the exemption and associated license amendnent would have either essentially the same or greater envirennental impact, i

Alternative Use of Resources:

This action does not involve the use of any resources different from or 2

• beyond the scope of resources used during normal plant operation, which were

. assessed in the Final Environrental Statenent relating to plant operation, i t NUREG-1064, dated December 1964, t

i Agencies _and Persons Consulted:  !

The Comission's staff reviewed the licensee's request that supports the proposed exemption. The staff did not consult other agencies or persons.

i FINDING OF _p,0,SIGNIFI,CApT, If, PAC,T Based upon the foregoing environmental assessment, the Comission concludes that the proposed action will not have a significant effect on the quality of I the hunan environment. Accordingly, the Comission has detemined r.ot to prepare l an environmental inpact statement for the proposed exemption and associated license amendment. i i

For further details with respect to this action, see the request for  :

exemption and applich'. ion for license amendment dated August 11, 1988. A :opy  !

of the above is available for public inspection at the Comission's Public f

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, Document Room, The Gelman Building, 2120 L Street, NW, Washington, C.C., 20555, i

and at the local public document room located at the Waterford Public Library, 49 Rope Ferry Road, Route 156, Waterford, Connecticut 06385.

Dated at Rockville, Maryland this 14th day of November , 1988, FOR THE NUCLEAR REGULATORY COMMISSION

,oh IF. Stolz, Direct '

Pr ject Directorate I-4 vision of Reactor Projects-l/II Of fice of Nuclear Reactor Regulation i

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