ML20128P507
| ML20128P507 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 06/14/1985 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | Reyes L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8507260429 | |
| Download: ML20128P507 (5) | |
Text
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b Northern States Power Ccmpany 414 Niconet Matt Minneapolis. Minnesota 55401 Telephone (612) 330-5500 June 14, 1985 L A Reyes, Chief Operations Branch U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Illinois. 60137 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 In response to your letter of May 17, 1985, concerning Inspection Report No.
50-282/85011 (DRS), the following information is offered related to the three noncompliance items cited in the report:
Violation 10 CFR Part 50, Appendix B, Criterion V as implemented by the Prairie Island Quality Assurance Plan, requires that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings which 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 leak rate testing required by Technical Specifications and 10CFR 50, Appendix J were not appropriate in that:
a.
The licensee's Containment Integrated Leak Rate Test (CILRT) procedure (s) did not address the area temperature survey requirements of ANSI N45.4-1972.
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- O A Reyag, Chicf Opr Br Juna 14, 1985 Page 2 Northem States Power Company b.
The licensee's CILRT procedure (s) did not adequately reflect the required 10 CFR Part 50, Appendix J, acceptance criteria of 0.75 Lt for the BN-TOP-1 or mass point calculated leakage at the upper 95% confidence level, c.
The licensee's CILRT procedure (s) allowed the licensee to terminate the supplemental verification test portion of the CILRT with the BN-TOP-1 calculated leakage outside of the test acceptance band.
This is a Severity Level IV violation (Supplement I).
Response
Procedures required to implement the leak rate testing stipulations of the Technical Specifications and 10 CFR 50, Appendix J, will be changed prior to the next Integrated Leakage Rate Test at Prairie Island.
Specifically, the procedures will address the following:
a)
An area temperature survey will be performed in the containment prior to pressurization of the containment.
The containment will be as close to the "as-tested" condition as circumstances permit.
Fans will be used for air circulation in any region where representative temperatures show appreciable variation, b)
Acceptance criteria for future tests will be 0.75 Lt or 0.75 La at the upper 95% confidence level using either the BN-TOP-1 or the mass point calculation techniques.
c)
The supplemental verification test portion of the CILRT will be calculated using the same calculation technique as the Type A test.
Y 4 A R:yma, Chief Opr Br Jun2 14, 1985 Page 3 Northem States Power Company Violation Prairie Island Technical Specification 6.5 requires detailed written procedures, including the applicable checkoff lists and instructions, covering surveillance and testing requirements that could have an effect on nuclear safety shall be prepared and followed.
Contrary to the above, procedure SP-1071(8) Revision 0, step 3.15 required a BN-TOP-1 supplemental verification test of 11.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />, yet, the verification test was only 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> long and this step of the procedure was signed off.
This is a Severity Level IV violation (Supplement I).
Response
The verification test was terminated after five hours due to acceptable results and an interpretation of the word "approximately" in the BN-TOP-1 section related to verification test duration. To remedy this situation in future tests, the word approximately, when applied to supplemental test duration, will be defined as plus or minus ten percent of the Type A test duration. Furthermore, Prairie Island will not perform a CILRT using BN-TOP-1 methodology for Type A durations greater than 18.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br />.
Violation 10 CFR 50, Appendix J, paragraph III. A.1 requires that "During the period between the initiation of the containment inspection and the performance of the Type A test, no repairs or adjustments shall be made so that the containment can be tested in as close to the "as is" condition as practical."
10 CFR 50, Appendix J, paragraph III.A.3.(a) requires that all Type A tests can be conducted in accordance with the provisions of ANSI N45.4-1972. ANSI N45.4-1972 paragraph 4.2 requires "For retesting, an initial record proof test shall be conducted at time periods and pressures established by the responsible organization, before any preparatory repairs are made. This will disclose the normal state of repair of the containment structure and a record of the results shall be retained."
t A Rsy:0, Chief Opr Br June 14, 1985 Page 4 Northem States Power Company Contrary to the above, the licensee performed repairs to penetrations prior to performing the Type A test and failed to add the pre-and post-repair differen-tial leakage to obtain an as found value for containment leakage.
This is a Severity Level V violation (Supplement I).
Response
This noncompliance is based on an interpretation that differs from what has been accepted for many years. This interpretation involves the timing of I
containment integrated leak rate tests with respect to repairs on local penetra-tions.
It has been our policy to conduct integrated leak rate tests at the end of refueling outages to provide assurance 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 interpreted to require an "as found" integrated leakage rate test. A strict interpretation of this requirement would mean conducting 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 clarified this matter in a memo-randum to Mr. James Sniezek in 1982. A copy of this memorandum was provided to us for the first time with a recent inspection report for our Monticello plant.
We will revise our procedures prior to the next integrated leak rate test to incorporate the guidance in this memorandum.
We do believe, however, that this is not 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 contain-ment attachments. Type A tests are performed about every third outage and have l
the primary purpose of assuring that containment shell weld seams and other structural parts of the containment which cannot be locally tested are leak tight. Correcting the Type A test results with the difference between 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.
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.' 'L ' A R:y00, Chisf Opr Br
-Juna.14, 1985 Page 5 Periodic. Type B and C tests include both as found and as left results as documented in the: master local leak test procedure. An exemption request from Appendix J requirements will be submitted to NRR to clarify the acceptability of performing local repairs prior to a future Type A test.
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.
-m C E Larson Vice President Nuclear Generating CEL/vj' c: Regional Administrator - III, NRC Resident Inspector, NRC G. Charnoff i
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