ML20238E130
| ML20238E130 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/28/1987 |
| From: | Mroczka E, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20238E132 | List: |
| References | |
| B12686, NUDOCS 8801050012 | |
| Download: ML20238E130 (4) | |
Text
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L J %.Z'"00,*cg; (203) 665-5000 December 28, 1987 Docket No. 50-336 B12686 Re: 10CFR50.90 U.
S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.
20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 Proposed Revision to Technical Specifications Containment Systems Pursuant to 10 CFR 50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License, No.
DPR-65, by incorporating the changes identified in Attachment 1 into the Technical Specifications of Millstone Unit No.
2.
Backcround The proposed change reflects the fact that more current engi-neering and computational methodologies are being utilized to calculate the containment leakage rate during an Integrated Leak Rate Test (ILRT).
The combination of the following factors vill yield an ILRT measurement system with minimal systematic instru-mentation errors as explained below:
o ILRT test instrumentation is selected to fall within the accuracy guidelines of ANS 56.8-1981.
o Engineering calculations of Instrumentation Selection Guide (ISG) determination are completed to ensure system measure-ment errors are less than or equal to 0.25 La.
o Temporary Precision Pressure Gages and Verification Flow Transmitter instrumentation is calibrated and National Bureau of Standards (NBS) traceable calibration certifica-tion is recorded to ensure compliance with ANS 56.8-1981.
o Permanent plant temperature and dewcell instrumentation is calibrated by approved plant procedures and is NBS trace-able.
8801050012 071228 gr/
[k PDR ADOCK 05000336 00
'U.S.
Nuclear Regulatory Commission B12686/Page 2 December 28, 1987 Description of Chance The proposed changes will delete the (pre-ANSI /ANS 56.8-1981) instrument error analysis criteria applicable to manual-type ILRT
. data acquisition-reduction processing and the leakage rate computations, and add explicit wording, calling for an. instrument error analysis evaluation.
This will ensure the measurement system can detect and "see" subtle fluctuations of containment air mass over time.
Technical Specification page 3/4 6-4 in reflects the proposed change.
Safety Assessment The ILRT Software Program, which NNECO uses to process the measurement system
- data, utilizes accepted engineering and statistical methodologies as specified in ANSI /ANS 56.8-1981.
The code is used to calculate a least squares fit (LSF) and 95 percent upper confidence limit (UCL) of L (the total measured containment leakage rate at the calcul$Eed peak containment
)
pressure during a
design basis accident, P
- Finally, an
]
independent verification test is conducted, us$n)g an NBS trace-able flow measurement device.
The test induces a known leakage rate out of the containment (and through the flow device).
The flow meter's measured leakage rate is then compared to the measured rate and calculated by the ILRT Software Measurement System.
An engineering calculation is then completed to verify that the ILRT Measurement System's leakage rate is within ANSI /ANS 56.8-1981 ineytality limite.
Significant Hazards Consideration NNECO hdE reviewed the proposed changes, in accordance with 10CFR50.92, and has concluded that they do not involve a signifi-cant hazards consideration in that these changes would not:
1.
Involve a significant increase in the probability or conse-quences of an accident previously evaluated.
Rewording the existing Technical Specification more clearly articulates the manner in which the ILRT test data are analyzed and statistically evaluated.
2.
Create the possibility of a new or different kind of acci-dent from any previously analyzed.
There are no failure modes associated with this change and therefore, there will not be a new, unanalyzed accident.
3.
Involve a significant reduction in a margin of safety.
This is a Surveillance Requirement change, and there is no direct impact on the boundaries or their safety limits.
The improved analytical methodology provides added assurance that containment integrity will continue to be maintained.
The commission has provided guidance concerning the application of standards in 10 CFR 50.92 by providing certain examples
U.S.
Nuclear Regulatory Commission B12686/Page 3 December 28, 1987 (March 6,
- 1986, 51FR7751).
The changes proposed herein most closely resemble example (i), a purely administrative change to Technical Specifications:
for example, a change to achieve consistency throughout the Technical Specifications, correction of an error or change in nomenclature.
The re-wording of ILRT Surveillance Requirements reflects the current upgraded computerized approach which is consistent with the requirements of 10 CFR 50 Appendix J,
and follows the guidance of ANSI N45.4-1972, and guidelines of ANSI 56.8-1981.
The Millstone Unit No. 2 Nuclear Review Board has reviewed and approved the attached proposed revisions and has concurred with the above determinations.
This propose g change is requested to be issued in February, 1988 to allow Millstone Unit No.
2 to accurately perform an instrument error analysis evaluation tb support our Type A ILRT this outage.
In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment.
Pursuant to the requirements of 10CFR170.12(c),
enclosed with this amendment request is the application fee of $150.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY Y
. Y\\ [c0 L
E. J. Mroczka
Senior Vice President By:
C.
F. Sears Vice President Attachment cc:
Mr. Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, CT 06116 (1)
The current outage schedule calls for the conduct of a Type A ILRT in February 1988; accordingly, we believe it preferable that this amendment be issued on or before this activity is complete.
If the outage schedule changes, NNECO will inform the NRC Project Manager by telephone.
U.S.
Nuclear Regulatory Commission B12686/Page 4 December 28, 1987 W.
T.
Russell, Region I Administrator D.
H. Jaffe, NRC Project Manager, Millstone Unit No. 2 W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos.
1, 2,
and 3 STATE OF CONNECTICUT)) ss. Berlin COUNTY OF HARTFORD
)
Then personally appeared before me, C.
F.
Sears, who being duly sworn, did state that as Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensee herein, and that the statements contained in said information are true and correct to t. efbest of his knowledge and belief.
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