ML20245A360
| ML20245A360 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/11/1986 |
| From: | Gibson A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Holahan G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20244D710 | List:
|
| References | |
| TAC-52665, NUDOCS 8703200193 | |
| Download: ML20245A360 (2) | |
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am,119 86 Gary Holahan, Director, Operating Reactor Assessment Staff NRR MEM3RANDUM FOR:
Albert F. Gibson, Director, Division of Reactor Safety FROM:
REQUEST FOR CLARIFICATION OF PIRIOD OF TEST WHE
SUBJECT:
AN INTEGRATED LEAK RATE TEST (ILRT) - OCONEE UNIT 1 An' inspection o'f an integrated leak rate test (1LRT) at Oconee Unit I was recent-(See ly conducted and an issue was identified regarding the period of test. Appen enclosed Inspection Report 50-269/86-13).
ANSI N45.4-1972 as the acceptable test method. (10 CFR 50. Appendix J.
III.A.3.(a))
During the ILRT at Oconee 1, problems were experienced such that the period of test was' approximately 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />. collected was in error or not a Region 11 determined that this resulted in a failed test since the period of tes was less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and the data would not pass the calculation method of The BN-TOP-1, which is accepted by the NRC as a shorter than 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test.
licensee stated that paragraph 7.6 of ANSI N45.4 allows him to detemine if a shorter period of test is acceptable and, therefore, if the test is successful or Paragraph 7.6 of ANSI N45.4 states that the leakage rate test period for It also states that... "If it can be not.
any method shall be at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
demonstrated to the satisfaction of those responsible f shorter test period, the agreed upon shorter period may be used."
Region 11 believes that a deviation from a clearly st in this case the f
approval of the regulatory body that established the rule:While w containment structure, he is responsible for assuring that the containment NRC.
structure is acceptable relative to design specifications, standards and func-tional performance testing which have been reviewed and fcend acceptable t I
Consequently, we believe that the reference to "... those responsible...*
in paragraph 7.6 of ANSI N45.4 requires that the NRC must review and accept NRC.
This alteration of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test requirement before it is implemented. There are situation appears analogous to changing a Technical Specification.
methods for altering a specification, but any change cust be reviewed and accepted by the NRC prior to implementation.
The issue is identified as an unresolved item in the enclosed inspection re We request clarification of paragraph 7.6 of ANSI N45.4 as to who makes the determination of acceptability of a shorter.than 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test period.
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2 3 gg Gary Holahan If you require additional details or discussion on this matter please contact H. Whitener (FTS 242-5593) or F. Jape (FTS 242-4182).
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Albertf.Gibson
Enclosure:
HRC Inspection Report No. 50-269/86-13 cc w/ enc 1:
H. Pastis, NRR J. F. Stolz, NRR R. Weller, NRR G. Arndt, NRR
- 5. Ebneter, R1 J. Paperiello, RIII E. Johnson, RIV D. Kirsch, RV bcc w/ enc 1:
V. Brownlee F. Jape H. Whitener
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sp JUN $0 W Docket No. 50-269 License No. OPR-38 Duke Power Company Mr. N. B. Tucker, Vice President ATTN:
Nuclear Production Department 422 South Church Street Charlotte, NC 28242 Gentlemen:
SUBJECT:
HRC INSPECTION REPORT NO. 50-265/86-13 This refers to the Nuclear Regulatory Commission (NRC) inspec H. L. Whitener en April 4-9, 1986.
At the conclusion of the inspection, ties authorized for-your Oconee facility.the findings were discus enclosed inspection report.
Within these Areas examined during the inspection are identified in the report.
areas, the inspection consisted of selective ex in progress.
Your attention is invited to unresolved items identified in the inspec This matter will be pursued during future inspections.
In accordance with Section,2.790 of the NRC's " Rules of Practice
- Title 10, Code of Federal Regulations,- a copy of this letter and its will be placed in the NRC Public Document Room.
Should you have any questions concerning this letter, please contact us.
Sincerely, It M Virgil L. Brow-lee, Chief beactor Projects Branch 3 Division of Rea: tor Projects
Enclosure:
(See page 2) l b
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RRC Inspection Report cc w/ enc 1:
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Repert No.: 50-269/86-23 Licensee: Duke Power Company 422 South Church Street Charlotte, NC 28242 License No.: DPR-38 Docket No.: 50-269 Facility Name: Oconee 1 Inspection Conducted: April 4-9, 1986 d b N
[ d b.e A Date signed Inspector:
H: L. Whitener YAb fh s2,
A Date Signed Approved by: F. Jape, Section Chief g/
Engineering Branch Division of Reactor Safety StWARY This routine, announced inspection involved witnessing the containtnent integrated leak rate test and reviewing the test procedure.
Scope:
No violations or deviations were identified.
Results:
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REPORT DETAILS 1.
Persons Contacted Licensee Employees
'M. 5. Tuckman, Station knager
- T. Barr, Superintendent Technical Services
- R. Todd, Performance
- K. Rohde, Performance W. Suslick, General Office R. Bond, Performance-
- D. Compton, Compliance NRC Resident Inspectors J. Bryant, Senior Resident Inspector
- K. Sasser, Resident Inspector
- Attended exit interview Exit Interview 2.
The inspection scope and findings were summartred on April 9,19 h
those persons indicated in paragraph I above and in subseque calls on m y 27 and 29, 1986.
The following new items and discussed in detat1'the inspection findings.
were identified:
Review any developments which may alter Unresolved item 269/86-13-01:
- Further, the Region 11 position on paragraph 7.6 of ANSI N45.4-1972.
review the results of the licensee's investigation as to the cau the problems which occurred during the test results based on less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of data.
Verify the licensee's validation of RTD Unresolved Item 269/86-13-D2:
accuracy over the range of use and any data corrections, if re paragraph 5.d.(2)(b).
The licensee did not identify as proprietary any of the sateri to or reviewed by the inspector during this inspection.
Licensee Action on Previous Enforcement Matters 3.
This subject was not addressed in the inspection.
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Unresolved Itees Unresolved itees are matters about which mere information is 1 require acceptable or may involve violations or determine whether they,areTwo new unresolved items identified during this. inspec discussed in paragraphs 5.d.1, 5.d.(2)(a), and 5.d.(2)(b).
deviations.
1 (70313) (70307)
Containment. integrated Leak Rate Test - Unit 5.
The inspector reviewed and witnessed test activities to determine tha primary containment integrated teak rate test was performed in ac Technical Specification 4.4.1 Appendix J to with the requirements of test procedure PT/1/A/0150/03A, " React or 10 CFR 50, ANSI-N45.4 and the Building Integrated Leak Rate Test."
licensee's activities which were inspected (1) review of the test procedure to verify that the procedure w of the Selected sampling and' conformed with the regulatory requirements; included:
(2) observation of test performance to detemine that test prere properly approved li-were coepleted, special equipment was installed, instrumentation was brated, and appropriate data were recorded; and (3) preliminary of leakage rate test results to verify that leak rate limits were met.
Pertinent aspects are discussed in the following paragraphs.
General Observations a.
The inspector witnetsed and reviewed portions of the test prepa containment pressurization, temperature stabilization and data The following areas processing during the period of April 4-g, 1956.
were inspected:
The test was conducted in accordance with an approved proce (3)
Test prerequisites selected for review wre found to be com (2)
Selected plant systems required to maintain test control were (3) found to be operational.
Special test instrumentation was reviewed and found to (4) stalled and calibrated.
Data required for the performance of the containment leat.
calculations were recorded at five-sinute intervals.
(5)
Problems encountered during the test wre described in the (6) event log.
3 (7). Temperature, pressure, dew point, and flow data were recor five-minute intervals.
evaluation and analysis by the licensee. A final ILRT report will be submitted to the NRC.
h tion of
. No problems were ide'ntified in the above areas with t e excepTh j'
iters (4) and (5).
b.
Procedure Review The inspector reviewed portions of PT/1/A/0150/03A to verify that test specified.
controls, valve alignments and acceptance criteria were Some problems were identified relating to the duration of the Type A test and application of the limits for the imposed leal rate.
Regarding the calculation of the imposed lest rate in convert - scfm to wt 5/ day.
In calev1 sting the limits of the d
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, verification test per Enclosure.13.3 the licensee had ina vertent y These minor 20.25(0.75La) rather than 20.25La.
used an error band ofdiscrepancies were resolved and htd no impa the. test results.
Regarding the test duration, the acceptance criteria in test procedure PT/1/A/0150/03A specified a short duration test, minimum length of the Step 9.1 of this procedure further specified thatAppendix J eight hours.
mass plot method would be used to calculate th into the leak rate test regulations.
that, as'part of the regulations, ANSI-N45.4, parag l
At this time, the only test of less than 24-hour duration
)
which is acceptable to the NRC is the method specified in BN-TOP-1, the NRC.
Revision 1. This test method requires total time a ANSI /ANS-56.8 which delineates the error analysis forI analysis method.
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Integrated Leat Rate Test c.
After Containment pressurization was started at h15 psig was obtained and the compressors were isolated at 12:24 a.m.
April 6.
1 on Containment temperature stabilization was achieved at 11:00 a.m.
The Type A leakage rate test (data collection) was started at this time and continued untti 11:00 l
April 6,1986.
test method mass point analysis:
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i 9.0965 wt. t/ day Calculated leakage rate 0.1053 wt. $/ day s
Upper 95%confidencelevel(UCL) 0.25 wt Eday Maximum allowable leakage rate 0.1875 wt. Eday 75% of maximum allowable leakage rate The acceptance criteria for the CILRT requires that the'opper bound of the leakage rate calculated at the 95% UCL, plus any required leakage rate additions, shall be less than 75% of the maximum The licensee did not find it necessary to make adjust-ments to account for local leakage, i.e., me isolation or repair of leakage rate.
However, certain problems were the test.
These problems are discussed leaks were made during identified with the above test results.
further in paragraph 5.d.(3), " Test Results."
A four hour supplemental test was performed in accordance w The licensee's recommendations of Appendix C of ANSI-N45.4-1972.
measured composite leak rate was within the upper and lower acce limit specified by the equation Lam + Lo - 0.25La '< Le < Lam +
0.25La for the Mass Point ar.alysis as indicated below:
0.187 wt. E < 0.2BB wt.% < 0.312 wt.%
These values meet the requirements of Appendix J.
d.
Identified Issues (1) Test Duration The issue of test duration was discussed with indicated in paragraph 5.b.that a recent NRC staff review NRR to the the Deputy Director, from issued April 1,
- 1986, Inspection Prograes, IE, confirms the Division of This memorandum clearly states
- Director, position stated in paragraph 5.b.
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that the NRC staff is in agreement that th least for mass point analysis is at that the test duration the inspector stated that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
At the exit interview, extended over a 24-hour period, although the Type A test 11:00 a.m., April 7, 1986, instrument 11:00 a.m., April 6, tofailures and a discontinuity in the m less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (see the effective test data span to The inspector stated that paragraphs 5.d.(2)(a) and 5.d.(3)).in violation of Technical this situation appears to be Spectitcation 4.4.1 and Appendix J to 10 CFR 50 whic AN57-N45.4-1972 into the regulations.
as an unresolved item pending review by Region 11 m In subsequent telephone further evaluation of the test data.
discussions with the licensee, Region II identified the fai record a consistent mass trend of indep
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apparent violation.
In these discussions, the' licensee stated that he. believes the requirements of AN51-ti45.4-1972, paragraph 7.6 gives authority to the leak rate test engineers to alter the 24-hour time requirement.
The first sentence of paragraph 7.6 clearly states that, "The leakage rate test period, for any shall extend to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />..."
The second sentence of
- method, paragraph 7.6 states that, *1f it can be demonstrated to the satisfaction of those responsible for the acceptance of the J
containment structure that the leakage rate can be accurately detemined during a shorter test period, the agreed-upon shorter period may be used." The licensee contends that this statement allows his engineers to agree upon a shorter time period and deviate from the time period of 24' hours specified in the first sentence of paragraph 7.6.
Region 11 does not concur with the licensee's position on paragraph 7.6 of ANSI-N45.4-1972. The Region believes that the sentence is simply a statement of the obvious; second specifically, that with the review and approval of the regulatory body that initially approved the rule, in this case the NRC, an acceptable alternate to the requirements of that rule may be teplemented. The Region also believes that the NRC staff review discussed above supports this position. However, upon request from the licensee for time to pursue clarification of the meaning of paragraph 7.6, Region management has categorized this matter as unresolved as follows:
269/86-13-01: Review any developments which Unresolv~ed Item may alter the Region II position or paragraph 7.6 of ANSI Further, review the results of the licensee's N45.4-1972.
investigation as to the cause of the problems which occurred during the test, the ef fect these problems may have on test results, and the justification for acceptance of test results based on less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of data.
(2) Instrumentation (a) Loss of Temperature Sensors At about 3:00 p.m., on April 6, the licensee realized that a process board had failed in a manner which caused RTDs 2 through 7 to read about 10 degrees high from the start of the The board was replaced.
Rather than l
test at 11:00 a.m..
restarting the test at 3:45 p.m. on April 6, when the RTDs were returned to service, the licensee ssed the difference between the repaired RTDs and RTDs in steilar locations, which had mot f ailed, to generate the temperatures for RTDs 2 through 7 for the time period 11:00 a.m. to 3:45 p.m. on The same board failed again and data for RTDs 2 April 6.
through 7 was lost from 7:25 a.m. to 8:15 a.m. on April 7.
In this case, the last functional reading for RTDs 2 through
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I 7 was used. The licensee concluded that the manipulation of these data did not affect test results because the containment air temperature was stable and only, very small-changes in temperature would occur ever the time period for which these data were artiff cially generated.
The inspector's position on this matter was that the basis of the mass point analysis is a statistical analysis to determine the best fit line to the data and to calculate confidence error.
The statistical analysis assumes random scatter in the data, Forcing 25% (six determined from independent observations.
RTDs) of the temperature sensors to track other sensors has.
the potential to affect both the least square fit and the confidence interval calculations.
If these data from 11:00 a.m. to 3:45 p.m. on April 6 are excluded, the test At the time is reduced to less than the required 24-hours.
exit interview, the inspector identified this matter as a potential violation for the -following reasons:
The licensee's Technical Specification 4.4.1 and Appendix J to 10 CFR 50, paragraph III incorporate the into the regulations.
requirements of AN51-N45.4-1972 the test Paragraph 7.6 of AN51-N45.4 requires that period shall extend to 24-hours.
leak Para' graph 7.9 of ANSI-N45.4 further state for 24 consecutive hours.
pressure Paragraph 7.8 of ANSI-N45.4 requires.that temperature and humidity ) observations (analysis i
shall be made at hourly or independent observations more frequent intervals.
Contrary to the above, the licensee did not record independent data observations on an hourly or more freque interval in the time period from 11:00 a.m. to 3:45 p.m. en Rejection of this time period results in a Further, a perturbation in l
April 6, 1986.
test duration of about 19-hours.
the mass trend at 10:00 p.m. (details in 9-hours (10:05 p.m. April 6 to 7:20 a.m I
about 1986).
(seeparagraph5.d.(1)).
a
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(b) Instrument Calibration In review of-instrument calibrations, the inspector
- found that the RTDs had been calibrated at only one point, 32*F.
The licensee stated that any probles with the RTDs would be
)
This matter was discussed with evident at the ice point.
personnel of the temperature measurements department of the National Bureau of Standards who indicated that a true calibration would include comparison with a known standard at Further, paragraph 6.2 of I
a minimum of three points.
AN51-N45.4 indicates that a comparison with a known standard In further should be made over a range of temperatures.-
discussions on this item, the licensee stated that a misunderstanding may have occurred.
He believes that documentation of a multipoint calibration exists.
This matter was identified as unresolved pending review of the
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Unresolved. Item 269/P6-13-02:
Review documentation:
temperature calibration documentation to verify that an adequate calibration over the range of use was performed, (3) Test Results Examination of the mas's plots at the end of the test showed that a The discontinuity occurred in the data et 10:05 p.m. on April 6.
mass plot showed a step increase of about 180 pounds.
The only perturbation which could be identified at this time wasThis is c an increase of 0.02 psi in the pres'sure readings.The mass trend rem tent with the mass change.
leak rate calculation of the earlier data which renders theBased on a preliminary evaluation of 0.096 wt. 5/ day inaccurate.a portion of the data, the leak rat Although this leak rate still with a UCL of 0.145 wt. 5 per day.
appears to be within the limit of 0.1875 wt. 5 per day the margin Further, a is reduced to about 0.04 wt. 5 per day.
I consistent mass trend for analysis is reduced to about 9-hours, for error 10:05 p.m. on April 6 to 7:20 a.m. on April 7,1986.
Re-evaluation of the Type A test data at the Region II office showed the following results:
Due to instrument failures and an unexplained discontinuity l
in mass trend, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of independent data observations 1.
linear mass vs. time relationship (based on assumption of a constant leak rate) were not available for yielding a analysis by the approved 24-hour total time mass point analysis by the methods specified in 24-hout ANSI /ANS 56.8.
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S Analysis of data free 30:05 p.m. April 6 to 7:20 a.m. on April 7, in which there are no apparent 1mstement failures 2.
or discontinuity in the linear mass trend show that the test does not meet the criteria of the NRC accepted methodology of BH-TOP-1, Rev.1 for the temination of a Type A test in less Specifically, the total time analysis per than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
BN-TOP-1, REv. I shows ah upper confidence limit of about 0.42 wt% per day which is greater than the allowable-limit of 4
0.1875 wt% per day.
As indicated above, the 9k hour span of consistent data show a leat rate of 0.138 wt% per day and a UCL of 0.145 wt.% per day by tfhile this leak rate may be a reasonable
. sass point analysis.
representation of the containment leakage, the inspector does not have specific NRC approved and issued criteria to judge the acceptability of a short duration, mass-point test.
Final acceptance of the Type A test result is deferred pending a review of the cause of the instrument f ailures and the perturbation in the mass trend and the possible effect of thes problems on the test results.
stated that an evaluation and analysis of these events would be included in the containment leak rate test report to the NRC.
Review of this comitment has been incorporated into unresolved item 269/86-13-01, paragraph 5.d.(1).
(4) As-Found Leak Rate The The licensee bid not yet determined the as-found leak rate.
inspector stated that his understanding is that determination the as-found leak rate is a requirement but the Resolution of this Type A test is appropriate corrective action. matter w rate.
(5) Outstanding Item Review concerned improvement in Inspection followup item (287/84-12-01) control of field activity relative to making repairs or adjustments to boundary valves during a Type A test.
The inspector found that specific instructions have been includ procedure PT/3/A/0150/03B to prohibit any repair or adjustment to valves prior to review and approval by the tes the test director.
This item is closed.
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APPENDIX J CLARIFICATION REQUEST I
6/12/86 Caller:
Clifford Clark,414* (FTS) 463-3741 Question:
A plant's "24-hour CILRT had the following results:
Total Time (TT): L,, ( tech specs 95%UCL)techspecs Mass Point (MP): L,( tech specs 95% UCL ( tech specs Licensee claimed this CILRT was acceptable because TT 951 UCL is not applicable to a 24-hour test.
Discussion with Y.S. Huang, NRR, confinned that this ILRT was Survey:
technically acceptable, but that the licensee's reasoning was The 95% UCL would continue to be applicable regardless incorrect.
of test duration. However, based on the 4/1/86 Eisenhut, NRR, memo to Partlow, IE, this test, having met its tech spec limits by use of the MP method, would be considered technically acceptable.
G. Arndt infonned C. Clark of the above clarification. He also
Response
advised C. Clark that this was a technical clarification, and recomended'that its acceptability be checked through this particular plant's nonnal NRC licensing chain.
E.)3unter Arn t MJEB/DET/RES Subsequently, G. Arlotto, RES, sent a memo to W. Olmstead, ELD, on July 8,1986, requesting ELD clarification of the legal acceptability of l
Note:
I using the 4/1/86 memo as a basis for passing a CILRT.
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