ML20129A302
| ML20129A302 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 05/24/1985 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | Spessard R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8506040527 | |
| Download: ML20129A302 (6) | |
Text
l Northern States Power Company 414 Nicollet Mali Minneapoks, Minnesota 55401 Telephone (6121330-5500 May 24, 1985 Mr R L Spessard, Director Division of Reactor Safety U S Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 LICENSE NO. DPR-22 In response to your letter of April 12, 1985, concerning Inspec-tion Report No. 50-263/84036 (DRS), the following information is offered related to the two noncompliance items and the two unre-solved items cited in the report:
Violation Monticello Technical Specifications 6.5.C paragraph I re-quires detailed written procedures, including the applicable check-off lists and instructions covering routine testing of Engineering Safeguards and equipment as required by the faci-lity license and Technical Specifications, be prepared and followed.
10 CFR Part 50, Appendix B, Criterion V as implemented by the Monticello Quality Assurance Plan, requires " activities affecting quality shall be prescribed by documented instruc-tions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings... instructions, procedures or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished."
Contrary to the above the procedures required to implement the Icak rate testing required by Technical Specifications and 10 CFR 50, Appendix J were not appropriate in that:
- a. Part B in procedure Number 136, Revision 5 did not adequa-tely describe the type of data reduction method to be used for the primary containment integrated leak rate test, nor did it contain adequate acceptance criteria for any data reduction method that could be used. Additionally, Appen-
' dix E of the procedure incorrectly described the data l
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Northem States Power Company reduction method the licensee wished to use (BNMP-1, Total Time method).
- b. Procedure Test Number 137, Revison 12 allowed an unaccep-table method to be used to total or sum the total leakage-rate required by Technical Specification 4.7.A.2 for tes-table penetrations and isolation valves.
Response Part A Appendix E of the Monticello Integrated Ieak Rate Test Proce-dure describes three methods of data reduction:
the point to point method, mass plot method, and the total time method.
All three data reduction methods were used for the_ test with the intention of conducting a short duration test, as permit-ted by the Technical Specifications, if this was possible. If this was not possible, the test duration would be extended to at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. A short duration test is permissible if the requirements of Bechtel Topical Report BN-TOP-1 are sat-isfied.
If a short duration test was not possible, a test lasting at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be performed using the methods described in ANSI /ANS 56.8-1981. BN-TOP-1 methodology uses the total-time method of data reduction and ANSI /ANS 56.8-1981 uses the mass plot method of data reduc-
. tion.
We believe the procedure adequately described the type of data reduction methods that were used in the test.
Our review of the procedure, however, found that temperature stabilization criteria of BN-TOP-1 were not included. The criteria from ANSI /ANS 56.8-1981 were included, however.
During the test it was noted that the stabilization criteria of BN-TOP-1 were met prior to meeting the criteria of ANSI /ANS 56.8-1981. Many of the other acceptance criteria of BN-MP-1 were not quoted in the test procedure.
- However, equivalent requirements were=in place in most cases.
The test procedure was found to contain two inaccuracies in the description of the 95% confidence interval calculation for the total time method.
The computer program used in the data reduction correctly performed this calculation, however.
All of the procedure deviations discussed above were corrected through temporary changes to the integrated leak rate test procedure prior to the start of data taking.
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3.
Northem States Power Company Besponse Part B This item is essentially the same as the second noncompliance item contained in the inspection report and will be discussed below.
Violation Monticello Technical Specification 4.7.A.2 paragraph f re-quires the total leakage rate for. double-gasketed seals be demonstrated to be less than 34.4 standard cubic foot per hour (SCFH) and the total. leakage rate for testable penetra-tions and isolation valves except main steam isolation valves be ' demonstrated to be less than 103.2 scfh.
Contrary to the above, the licensee failed to demonstrate that the total leakage rate for penetrations and isolation valves was less than the Technical Specification allowable.
Prior to startup the licensee made repairs and adjustments to make sure that the technical specification requirements were met.
Response
The inspector has interpretated Monticello Technical Specifi-cation 4.7. A.2 to require the sum of all individual leakage measurements to be less than the penetration total specified in the Technical Specifications.
These totals are consider-ably more conservative that the requirements of 10 CFR Part 50, Appendix J and predate the issuance of Appendix J by the Commission.
In a penetration with two isolation valves, the inspector indicates that the proper interpretation of the Technical Specification requirement is that both valve leakages be added into the penetration total. We do not believe this is the intended interpretation of this requirement.
Technical Specification changes are currently being drafted for submit-tal to the Office of Nuclear Reactor Regulation to clarify this matter and conform the Technical Specifications to the requirements of Appendix J.
Prior to startup, additional maintenance work was performed to bring the total leakage into conformance with the inspec-tor's interpretation of the technical specification requirement.
Unresolved Item No. 1 Unresolved item (263/84026-01(DRS)) identified concerns that we have relative to venting and draining non-seismic Class 1 systems that penetrate primary containment for Type A tests.
In your response to this' inspection report, please include a list of the systems penetrating containment which were not vented and drained outside of containment for the 1984 CILRT
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Northern States Power Company with the justification used to not vent and drain these systems.
Resegnse The Appendix J requirement for ensuring that all containment penetrations are exposed to test differential pressure has been met in the past at Monticello by venting the reactor coolant system (which is assumed to rupture in an accident) to the containment atmosphere. Piping outside containment was assumed to remain intact following an accident. A com-bined loss of coolant accident and simultaneous failure of lines outside containment, from an earthquake perhaps, was not considered credible. Many older plants are not desig-ned for the extremely unlikely load combination of. loss of coolant plus design basis earthquake.
Attached to the inspection report was a copy of a memorandum written to R C Lewis, Region II, in 1981 which provides an NRC I&E interpreation of this requirement. We had previously not been provided with this interpretation, which requires draining and venting of non-seismically design systems.
Prior to the next integrated leak rate test we will revise the test procedure to include the guidance in this memorandum. We believe guidance of this nature, however, should not be used in the enforcement process unless it was previously distributed to the licensee.
To address draining and venting concerns for the 1984 integrated leak rate test, a penetration vent penalty was added to the Type A 95% upper confidence level measured. leak rate as reported in our March 29, 1985 report entitled,
" Reactor Containment Building Integrated Leak Rate Test Report." This penalty included all ECCS, non-ECCS, seismic, and non-seismic systems that were not vented during the test.
Unresolved Item No.2 Unresolved item (263/84026-07(DRS)) as contained in Section 7 of the report pertains to the "as is" or as found condition of the containment.
It is the NRC's position that the con-tainment failed the as found integrated leak rate test in 1980.
In your response to this inspection report please report the as found 1984 test results.
For future Type A tests we expect you to abide by the as found test requirement of 10 CFR 50, Appendix J, III. A and ANSI N45.4, Paragraph 4.2, and if a test fails we expect you to follow the require-ments of Appendix J, III. A.6 and Technical Specification 4.7.A.2.a.2.
Besaggse This unresolved item is also based on an interpretation that differs from what has been accepted for many years.
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Northem States Power Company
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This interpretation involves the timing of containment integ-rated leak rate tests with respect to repairs on local pene -
trations.
It has been our policy to conduct integrated leak rate tests at the end of refueling outages to provide assur-ance that the unit is being returned to service with a tight containment following a period of extensive maintenance and the opening of containment penetrations and hatches.
The inspector has indicated that Appendix J should be inter-preted to require an "as found" integrated leakage rate test.
-A strict interpretation of this requirement would mean conduc-ting integrated leak rate tests at the beginning of the outage. This is not the preferred course of action.
The NRC Office of Nuclear Reactor Regulation clairified this matter is a memorandum to Mr James Sniezek in 1982. A copy of this memorandum was provided to us for the first time with the inspection report. We will revise our procedures prior to the next integrated leak rate test to incorporate the guidance in this memorandum.
We do not believe, however, that this is a significant safety issue. Type B and Type C tests performed each refueling outage are the primary means of assuring the leak tightness of piping penetrations, hatches, and other containment attachments. Type A tests are performed about-every third outage and have the primary purpose of assuring that contain-ment shell weld seems and other structural parts of the containment which cannot be locally tested are leak tight.
Correcting the Type A test results with the difference be-tween as-found and as-left Type B and Type C leakage totals has the punitive effect of increasing the frequency of Type A testing without addressing the problem of excessive Type B and Type C leakage.
As-found 1964 local leak rate test results were reported to the NRC in our March 29, 1985 report.
Other tietters The Appendix J exemption requests identified as desireable by the inspector will be drafted and submitted to NRR for review and approval as well'as the Technical Specification changes discussed above. This will be completed in approximately 90
-days.
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Northem States Power Compsg -
We welcome the opportunity to discuss these issues with you in
.more detail. Please~ contact us if you have any questions related to our response.
- e C E Larson Vice President Nuclear Generation c:- Regional Administrator-III, NRC Resident Inspector, NRC G Charnoff a