ML20034H678
| ML20034H678 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 03/16/1993 |
| From: | Opeka J CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20034H679 | List: |
| References | |
| B14391, NUDOCS 9303190223 | |
| Download: ML20034H678 (5) | |
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4' NORTHEAST UTILETIES ceners ome... seioen street. semn. connecticut I
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P.O. BOX 270 HARTFORD. CONNECTICUT 06141-0270 J UEDSUNwC (203) 665-5000 k
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March 16, 1993 Docket No. 50-213 814391 Re:
10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Haddam Neck Plant Proposed Revision to Technical Specification Containment Leakaae Pursuant to 10CFR50.90, Connecticut Yankee Atomic Power Company (CYAPCO) hereby proposes to amend Facility Operating.l.icense' DPR-61 by incorporating the changes identified in Attachment 1 into the Technical. Specifications of the Haddam Neck Plant.
Description of the Proposed Chance The purpose of this change is to allow the Haddam Neck Plant to perform alternative methods of calculating containment integrated leakage rates during surveillance testing.
Currently, CYAPC0 is authorized via the technical specifications to only use ANSI ~ N45.4-1972. - This ' process entails ~ evaluation _-
of leakage on a total time method.
CYAPC0 proposes to modify thectechnical specifications to allow two additional methods of' testing to be performed:
the mass-point method conducted under ANSI. 56.8 or the total-time method conducted under BN-TOP-1.
All of the methods proposed to be used by.CYAPC0 have been.previously approved by the NRC Staff on other dockets. There are no changes required to be made to the bases.
On October 15, 1987,"' the NRC Staff granted. an Appendix J exemption to the Haddam Neck. Plant. to allow the use of the ANSI 56.8 mass-point method for a 24-hour leak rate test. '10CFR50 Appendix J has been revised since the Staff issued this exemption and now contains this test method, but the Haddam Neck Technical Specifications still direct the use of ANSI N45.4 only.
ANSI N45.4 does not cover the mass-point method.
(1)' F. M; Akstulewicz, Jr., letter to E. J. Mroczka, " Exemption from lthe Requirements of Appendix J to 10CFR Part 50, -Paragraph III.A.3," dated October 15, 1987.
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1 U.S. Nuclear Regulatory Commission B14391/Page 2 March 16, 1993 The total-time method, described in BN-TOP-1, is the only abbreviated test period leakage rate currently permitted by the NRC Staff.i28 The BN-TOP-1 method allows the test duration to be less than the 24-hour duration stated in ANSI N45.4-1972 when using the total-time method. However, successful passage is predicated on the magnitude and trends of the measured data and calculated leakage rates.
The leakage rate must be stable and the two-sided upper confidence limit for the total-time analysis must be less than 0.75 La where La is the maximum allowable leakage rate at pressure Pa.
In addition, at least 20 data points shall be taken at approximately equal intervals and the test must last at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Safety Assessment It has been recognized by the NRC Staff that the mass-point method is an acceptable means for calculation of containment leakage in addition to the total time, which is referenced in ANSI N45.4-1972 and endorsed by 10CFR50 l
Appendix J.
The mass-point method calculates the air mass at each point in time and plots it against time.
A linear regression line is plotted through-the mass-time points using a least squares fit. The slope of this line is the leakage rate.
In the total-time method, a series of leakage rates are calculated on the basis of air mass differences between an initial data point and each individual data point thereafter.
ANSI 56.8, which was intended to replace ANSI N45.4, specifies the use of the mass-point method, to the exclusion of the other method.
However, the NRC Staff has determined that these two methods (Mass Point and Total Time) are i
acceptable methods which may be used to calculate containment leakage rates.
This can be seen by the inclusion of ANSI N45.4 and ANSI 56.8 in 10CFR50 Appendix J.
In addition to the method of calculation, consideration of the length of time of the test must be included in the program.
Section 7.6 of ANSI N45.4 states that a test duration of less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is only allowed if approved by the NRC Staff.
Currently, the only approved methodology for such a test is contained in Bechtel Topical Report BN-TOP-1, Revision 1, " Testing Criteria for Integrated Leakage Rate Testing of Primary Containment Structures for Nuclear Power Plants."
This approach only allows the use of the total-time method. CYAPC0 also requests approval of this methodology.
Sianificant Hazards Consideration i
CYApC0 has reviewed the proposed change in accordance with 10CFR50.92 and has concluded that the change does not involve a
significant hazards consideration.
The bases for this conclusion is that the three criteria of l
(2) NRC Inspection and Enforcement Manual Inspection Procedure 70313,
" Containment Integrated Leak Rate Test Surveillance," dated November 25, 1985.
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'.S. I uclear Regulatory Commission U
B14391/Page 3 March 16, 1993 i
10CFR50.92(c) are not compromised.
The proposed change does not involve a significant hazards consideration because the change would not:
1.
Involve a significant increase in the probability of occurrence or consequences of an accident previously analyzed.
The performance of the test will verify the "as left" and "as found" condition of the containment.
This integrated leak rate test is performed to ensure that the containment integrity is in a satisfactory state prior to starting power operation.
The proposed change will modify the technical specifications to allow containment leakage to be tested with other methods that have already been approved by the NRC Staff and successfully used at other nuclear facilities.
This change has no impact on the probability of occurrence of any previously evaluated accidents.
The additional test methodologies that CYAPC0 proposes to use have been previously reviewed and approved by the NRC Staff and are recommended for use by national engineering organizations.
The consequences of any accidents previously evaluated are not affected since containment integrity will be tested and _ verified to be within existing limits by approved test methods.
2.
Create the possibility of a new or different kind of accident from any previously evaluated.
The potential for an unanalyzed accident is not created since there are no changes in the way the plant is operated.
The testing methodologies that CYAPC0 proposes on using are permitted for use by the NRC Staff.
These testing methodologies will ensure containment integrity is maintained within the existing limits.
3.
Involve a significant reduction in margin of safety.
The proposed change does not impact the safety limits of the containment
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or its protected boundaries.
The proposed change will. allow additional methods of testing to be performed which will verify containment integrity.
Since all methods that CYAPC0 proposes to use have been shown previously to adequately verify containment integrity, the margin of safety afforded by this test is not impacted.
Since the proposed change does ' not affect any accident previously analyzed or create any new-accidents, there is no reduction in a margin of. safety.
Moreover, the Commission has provided guidance concerning the application of the standards in 10CFR50.92 by providing certain examples- (March 6,
- 1986, 51FR7751) of amendments that are considered not likely to involve a significant hazards consideration.
The proposed modification is most like example (vii),
a change to conform a license to the changes in the regulations, where the license change results in very minor changes to the
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U.S. Nuclear Regulatory Commission B14391/Page 4 March 16, 1993 t
facility operations clearly in keeping with the _ regulations.
The facility operations affected by this technical specification change are the test methodology for the performance of Type A tests.
10CFR50. Appendix J now specifically authorizes the use of ANSI N45.4 and ANSI 56.8.
The use of BN-TOP-1 has been approved by the NRC Staff on other plant dockets, including t
Millstone Unit No. 1.
CYAPC0 has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations.
The proposed change does not involve a significant hazards consideration, nor increase the types and-amounts of effluents that may be released off site, nor signif_icantly increase individual or cumulative occupational radiation exposures.
Based on the foregoing, CYAPC0 concludes that the proposed chtnge meets the criteria delineated in 10CFR51.22(c)(9) for a
categorical exclusion from the requirements for an environmental impact statement.
The Haddam Neck Plant Nuclear Review Board has reviewed and approved the proposed change and has concurred with the above determination.
In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment.
Regarding our proposed schedule for this amendment, we respectfully request issuance by June 21, 1993, which will support our upcoming refueling outage.
The effective date of the amendment should be upon issuance.
We trust you will find this information satisfactory and remain available to discuss this with you at your convenience.
Very truly yours, I
CONNECTICUT YANKEE ATOMIC POWER COMPANY bb4I--
J. F. Opeka)
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Executive Vice President
.i cc:
T. T, Martin, Region I Administrator A. B. Wang, NRC Project Manager, Haddam Neck Plant l
W. J. Raymond, Senior Resident Inspector, Haddam Neck Plant l
l Mr. Kevin McCarthy, Director, Radiation Control Unit, l
Department of Environmental Protection, Hartford, CT 06116
4 U.S. Nuclear Regulatory Commission B14391/Page 5 March 16, 1993 Subscribed and. sworn to before me i
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