IR 05000266/1987008

Insp Repts 50-266/87-08 & 50-301/87-08 on 870406-10.No Violations or Deviations Noted.Major Areas Inspected: Licensee Action on Previous Findings,Containment Integrated Leak Rate Test Procedure,Test Witnessing & Results

ML20209J170
Person / Time
Site:	Point Beach
Issue date:	04/29/1987
From:	Mendez R, Wright G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20209J139	List: IR 05000266/1987008 ML20209J135
References
50-266-87-08, 50-266-87-8, 50-301-87-08, 50-301-87-8, NUDOCS 8705040230
Download: ML20209J170 (10)

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U.S. NUCLEAR REGULATORY COMMISSION

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REGION III

Report Nos. 50-266/87008; 50-301/87008 Dockets No. 50-266; 50-301 License Nos. DPR-24; DPR-27 Licensee: Wisconsin Electric Power Company 231 West Michigan Milwaukee, WI 53203 Facility Name: Point Beach Units 1 & 2 .

Inspection At: Two Creeks, WI Inspection Conducted: April 6-10, 1987

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Inspector: R. Mendez f/Pf/67 Date

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M le - M Approved By: G. C. Wright, Chief Y/D//7 Test Programs Section Date Inspection Summary Inspection on April 6-10, 1987 (Report No. 50-266/87008(DRS)50-301/87008(DRS))

Areas Inspected: Routine announced inspection by a Region III based inspector of licensee action on previous inspection findings; Containment Integrated Leak Rate Test (CILRT) procedure; CILRT performance witnessing; and CILRT result This inspection was conducted per Inspection Procedures No. 61720, 70307, 70313, 70323, 92701 and 9270 Results: In the areas inspected no violations or deviations were identified.

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DETAILS 1. Persons Contacted Wisconsin Electric Power Company

• T. J. Koehler, General Superintendent

• T. G. Staskal, Operations Engineer

• T. G. Malinowski, Licensing Engineer

• W. Pullins, ISI Engineer

• A. Fleutje, Administration Specialist

• J. B. Gill, Project Engineer

• P. H. Kohn, Nuclear Plant Engineer G. R. Sherwood, Nuclear Plant Engineer Bechtel Corporation L. Young, Engineering Specialist B. Patel, Engineering Specialist

• Denotes persons in attendance during the exit meeting on April 10, 1987.

The inspector also contacted other licensee personnel including members of the technical, operating and regulatory assurance staf . Licensee Action on Previous Inspection Findings (Closed) Open Item (266/84005-01): The licensee had not established controls for the assignment of and changes to the weighting factors for RTDs and dewcells. The inspector reviewed procedure WMTP 12.18,

" Containment Integrated Leak Rate Test" and verified that criteria for the volume fraction redistribution for failed sensors had been establishe (Closed) Open Item (266/84005-2): The licensee's ILRT procedure had not established data rejection criteria for outlying observations in the collection of data. Consequently, the licensee would not have a technical basis to reject erroneous data resulting from human or instrument error. The inspector reviewed procedure WMTP 12.18 and verified that the data rejection criteria established in ANSI 56.8-1981 to identify outliers at the 5% rejection level had been incorporated, (Closed) Open Item (266/86021-01; 301/86018-01): Measuring and test equipment identification numbers were not documented on Local Leak Rate Test (LLRT) results. The concern was that erroneous LLRT corrections could occur since the range and test equipment were not documente The inspector reviewed the results of recent local leak rate tests and observed that the instrument identification number and the range of the scale used were documented on all completed test form .

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d. (Closed) Violation (266/86021-02): Failure to verify the results of a Type A test with a valid supplemental test as required by 10 CFR 50, Appendix J. Appendix J requires that the difference between the supplemental test data and the Type A test data be within 0.25 Lt (0.071 wt%/ day). In this particular case the licensee's result was Ltm = 0.099 wt%. day. On February 4, 1987, the licensee responded to the above violation and stated that in the past they had experienced deficiencies with the instrumentation. To prevent this, the licensee stated that they had performed studies to develop a new instrumentation system and to determine sensor weighting factors. In addition, the licensee stated that they had purchased a new instrumentation system, repositioned sensors and added more sensors as a result of the stud During the current CILRT, the inspector reviewed the licensee's CILRT procedure WMTP 12.18 and verified that the sensor weighting factors were adequate and representative of the containment. In addition, the licensee performed an acceptable CILRT in October 1986 at Point

Beach Unit 2 and an acceptable CILRT during this inspection. Since the licensee has performed a set of three valid Type A tests in a 10 year service period, the voiding of the April 1984 CILRT did not place Unit 1 in violation of containment integrity.

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e. (Closed) Open Item (266/86021-03; 301/86018-02): Using the results provided in the 90 day CILRT reports to the NRC the inspector determined that in 1981 at Point Beach Unit 1 and 1982 at Point Beach Unit 2 tests were failures in the as-found condition. The licensee had performed repairs and adjustments and calculated the penalties for penetrations that were not in the ideal lineup configuration, but erroneously added the lineup penalties to the actual leakage rate rather than the Upper Confidence Level (UCL). Consequently, based on the results given in the report, the as-found containment leakage rate for Unit 1 was 0.799 wt%/ day (acceptance criteria is less than 0.212 wt%/ day) and the as-found leakage rate for Unit 2 was 0.217 wt%/ day (acceptance criteria is less than 0.201 wt%/ day).

On February 4, 1987, the licensee responded to the open item and stated that the leakage rate values for the penetrations that were not in the ideal lineup configuration were incorrec The licensee stated that the leakage rate values provided in the 90 day report had been calculated using the maximum pathway method instead of the required minimum pathway method. The licensee re-calculated the results of the two tests and concluded that the tests passed in the as-found conditio The inspector reviewed the results of local leak rate tests using ,

minimum pathway leakag For the October 1981 Unit 1 CILRT, the i

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total Type C penalties using the minimum pathway method was 15,000 SCCM or 0.018 wt%/ day. Adding this penalty to the 95% UCL value of l 0.068 wt%/ day makes the as-found containment leak rate 0.086 wt%/ da Since the acceptance criterion is 0.212 wt%/ day, the test passes in 1

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the as-found conditio I l

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For the April 1982 Unit 2 CILRT, the total Type C penalties using minimum pathway totaled 5,462 SCCM or 0.006 wt%/ da Adding this leak rate to the 95% UCL value of 0.072 wt/ day makes the as-found containment leakage rate 0.078 wt%/ day. Since the acceptance criterion is 0.201 wt/ day, the test passed in the as-found conditio . Containment Integrated Leak Rate Test Procedure Review Procedure Review

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The inspectors reviewed the licensee's procedure titled

" Containment Integrated Leakage Rate Test Unit 1," Revision 0, relative to the requirements of 10 CFR 50, Appendix J, ANSI N45.4-1972 and FSAR. All inspector comments were satisfactorily resolve Clarifications of Appendix J Requirements To ensure the licensee's understanding of Appendix J requirements, the inspector conducted numerous discussions with licensee personnel during the course of the inspection. The following is a summary of the clarifications discussed with the license (1) The only methods of data reduction acceptable to the NRC are total time or point-to point as described in ANSI N45.4-1972 including a statistically calculated instrument error analysis. The following options are available to the licensee and are suggested in the following order:

(a) Total time (<24 hour duration test) in accordance with Bechtel Corp. Topical Report BN-TOP-1, Revision Whenever this method is used BN-TOP-1 must be followed in its entirety except for any section which conflicts with Appendix J requirement (b) Total time (>24 hour duration test) using single sided 95% UC (c) Proposed Regulatory Guide MS 021-5, Regulatory Position 13. If this method is utilized the licensee must submit an exemption request to NRC and receive approval for its use prior to the expiration of the Type A test frequency requirements stated in the Technical Specification (2) Periodic Type A, B, and C tests must include as-found results as well as as-lef If Type B and C tests are conducted prior to a Type A the as-found condition of-the containment must be calculated by adding any improvements in leakage rates, which are the results of repairs and adjustments (RA), to the Type A test results using the

" minimum pathway leakage" methodolog This method requires that :

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(a) In the case where individual leak rates are assigned to two valves in series (both before and after the RA),

the penetration through leakage would simply be the smaller of the two valves' leak rate (b) In the case where a leak rate is obtained by pressurizing between two isolation valves and the individual valve's leak rate is not quantified, the as-found and as-left penetration through-leakage for each valve would be 50% of the measured leak rate if both valves are repaire (c) In the case where a leak rate is obtained by pressurizing between two isolation valves and only one valve is repaired, the as-found penetration leak rate would conservatively be the final measured leak rate, and the as-left penetration through leak rate would be zero (this assumes the repaired valve leaks zero).

Whenever a reduced pressure test is performed the leakage rate Ltm shall be less than 0.75 Lt. If local leakage measurements are taken to effect repairs in order to meet the acceptance criteria, these measurements shall be taken at a test pressure P (3) Penetrations which are required to be Type C tested as described

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intheFSARandSER,mustbeventedinsideandoutsidethe containment during the CILRT. All vented penetrations must be drained of water inside the containment and between the penetration valves to assure exposure of the containment is controlled by the requirement that the valves be subjected to the post-accident differential pressure, or proof that the system was built to stringent quality assurance standards comparable to those required for a seismic syste (4) Whenever penetration configurations during a CILRT deviate from the ideal, the results of LLRTs for such penetrations must be added as a penalty to the CILRT results at the 95% confidence level. This penetration leakage aenalty is determined using the " minimum pathway leakage" metlodology. This methodology is defined as the minimum leakage value that can be quantified through a penetration leakage path (e.g., the smallest leakage through two valves in series). This assumes no single active failure of redundant leakage barriers. Additionally, any increase in containment sump, fuel pool, reactor water, or suppression pool level during the course of the CILRT must be taken as a penalty to the CILRT results. If penalties exist, they must be added (subtraction is never permitted) to the upper confidence level of the CILRT result (5) The start of a CILRT must be noted in the test log at the time the licensee determines that the containment stabilization has been satisfactorily completed. Reinitializing a test in progress must be " forward looking," that is, the new start time must be the time at which the decision to restart is mad ,

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This also implies that the licensee has determined that the test has failed, and has enough data to quantify the leakage rate. Any deviation from these positions should be discussed, and documented, with the NRC inspector as they occur to avoid later invalidations of the test results. Examples of acceptable deviations of reinitializing the start time of the test in the-past are: time at which a leaking penetration which has an obvious effect on the test data was secured, accidental opening and later closing of a valve which has an obvious effect on the test data, the time at which an airlock outer door was closed and the inner door was ope (6) The supplemental or verification test should start within one hour after the completion of the CILRT. If problems are encountered in the start of the supplemental test, data-recording must continue and be considered part of the CILRT until the problems are corrected and the supplemental test can begi (7) For the supplemental test, the size of the. superimposed leak rate must be between 0.75 and 1.25 time the maximum allowable leak rate La. The higher the value, the better. The supplemental test must be of sufficient duration to demonstrate the accuracy of the test. The NRC looks for the results to stabilize within the acceptance criteria, rather than the results being within the acceptance criteria. Whenever the BN-TOP-1 methodology is being used, the length of the supplemental test cannot be less than approximately one-half the length of the CILR (8) During a CILRT, it may become necessary to reject or delete specific sensors or data points due to drifting or erroneous sensors, or data outliers. Data rejection criteria'should be developed and used so that there is a consistent, technical basis for data rejectio One example of an acceptable method for data outliers is described in an Appendix to ANSI /ANS 56.8-198 Sensor data rejection criteria should be plant specific and based upon a sensor's trend relative to the average scatter, slope and/or absolute output of the senso (9) The water level in the steam generators during the CILRT must be low enough to ensure it does not enter the main steam lines unless flooding of the main steam lines is called for in the loss of coolant emergency procedur (10) An acceptable method for determining if the sum of Type B and C tests exceeds the 0.60 La Appendix J limit is to utilize the

" maximum pathway leakage" metho This methodology is defined as the maximum leakage value that can be quantified through a penetration leakage path (e.g., the larger, not total, leakage of two valves in series). This assumes a single active failure to the better of two leakage barriers in series when performing Type B or C test .

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(11) Test connections must be administratively controlled to ensure their leak tightness or otherwise be subject to Type C testin One way to ensure their leak tightness is to cap, with a good seal, the test connection after its use. Proper administrative controls should ensure valve closure and cap re-installation within the local leak rate testing procedure, and with a checklist prior to unit restar (12) Whenever a valve is replaced, repaired, or repacked during an outage for which Type A, B, and/or C surveillance testing was scheduled, local leak rate testing for the as-found as well as the as-left condition must be performed on that penetration. In the case of a replaced valve, the as-found test can be waived if no other containment isolation valve of similar design exists at the sit No violations or deviations were identifie (4) Containment Integrated Leak Rate Test Witnessing (Unit 1) Instrumentation The inspector reviewed the calibration data and determined all the instruments used in the CILRT had been properly calibrated and that the correct weighting factors had been placed in the computer program as required. The following instrumentation was used throughout the test:

Tyjte Quantity RTDs 24 Dewcells 12 Pressure Gauges 2 Flowmeter 1 During the integrated leak rate test dewcell No. 2 and RTD No. 8 were deleted from the data scan due to erratic (step changes) behavior. The test results were recalculated using the other 11 dewcells and the other 23 RTD's with reassigned weighting factors. Noothersensorsordatasetswererejected during the tes Temperature Survey The inspector reviewed the temperature survey performed by the licensee prior to containment pressurization. The survey was performed with all containment fans off as were the CILRT, and the verification test. The results of the temperature survey were satisfactory for the containment condition under which the Type A test was performed. The survey confirmed that the temperature readings of the RTDs were representative of each containment subvolum . _ _ _ _ - _ - _ _ _ _ _ -

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. Witness of Test The inspector witnessed portions of the CILRT on April 8,1987, and noted that test prerequisites were met and that the-appropriate revision to.the surveillance procedure was followed by test personnel. Valve lineup for the following systems were-verified correct to insure that no fluid could enter the containment atmosphere and that proper venting and draining.was provide System Penetrations-Pressurizer Liquid Sample 288

"A" Steam Generator Sample 34B Component Cooling IP1A 15 and 17 Component Cooling IPIB 16 and 18 Service Air Supply to Containment 33C Hot Leg Sample 28A Pressurizer Steam Space Sample 28C Reactor Makeup Water to Containment 30C NitrogentoSafetyInjectionAccumulators 14C Instrument Air Supply 33A and 33B Nitrogen Supply Line to Pressurizer Relief Tank 14A Demineralized Water Supply to Containment 12A No violations or deviations were identifie . CILRT Results

, Reduced Pressure CILRT Data Evaluation Upon satisfactorily completion of the required stabilization period. An eight hour reduced pressure CILRT was performed at 45 psia on April 8, 1937, with data collected and reduced by the licensee every 15 minutes. The inspector independently monitored and evaluated leak rate and instrument performanc There was agreement between the inspector's and licensee's

results as indicated by the following summary (units are in

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weightpercentperday).

Measurement Licensee Inspector Leak rate measured duringILRT(Ltm) 0.083 0.083 Ltm at upper 95%

Confidence level 0.132 0.133 Appendix J acceptance criteria at 95% UCL: <0.75Lt or <0.212 weight percent per da . _ -

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b. Supplemental Test Data Evaluation After the satisfactory completion of the reduced pressure eight hour CILRT, a known leakage (based on the inspector's independent readings and calculations) of 6.02 SCFM, equivalent to 0.283 weight percent per day was induced. Data was collected and analyzed by the licensee every 15 minutes. The inspector independentlymonitoredandevaluatedleakratedatatoverify the licensee s results. After five hours, the supplemental test was terminated with satisfactory results as-indicated by the following summary (units are in weight percent per day).

Measurement Licensee Inspectors Measured leakage rate during supplemental, Lc 0.325 0.325 Induced Leakage rate, Lo 0.283 0.283 Lc - (Lo + Ltm) -0.041 -0.041 Appendix J acceptance criteria: -0.071 <[Lc-(Lo + Ltm)] <+0.07 As indicated above, the licensee's test verification resiilts were stable and within the acceptance criteria, c. CILRT Valve Lineup Penalties Due to penetration configuration which deviated from the penetration requirements for the CILRT, the results of local leak rate tests for each penetration must be added at the 95%

UC Since the licensee performed an as-found CILRT, the ,

results of local leak rate tests were not availabl The licensee has committed to quantify the minimum pathway leakage for the following penetrations or leakage paths:

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Penetration / Equipment Service Air '

Post Accident Containment Vent System Drain Line

"A" Reactor Coolant Pump Seal Injection

"B" Reactor Coolant Pump Seal Injection N2 Bottles and Accumulators Containment Pressure Transmitter Instrument Line Reactor Coolant Drain Tank Suction Line Sump "A" Drain Line Letdown Aux Charging Charging Although, the licensee has not completed testing all valves which deviated from the ideal penetration valve lineup requirements, it is not anticipated that it will have a marked effect on the containment leakage rate. However, it is the

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licensee's responsibility to ensure that the results of local leak rate tests on the above penetrations do not cause the containment to leak in excess of the allowable leakage before containment integrity is require As-Found Condition of CILRT Results The as-found condition is the status of the containment at the beginning of the outage prior to any repairs or adjustments to the containment boundary. -The as-found Type A CILR test result can then be obtained by adding required adjustments to the overall Type A test resul Prior to the start of the CILRT, the licensee had determined that the steam generator level isolation valve, which are part of the containment boundary, were leaking through the valve packing. The licensee removed the valves and installed new valves prior to the start of the CILR Replacement of the valves was performed in accordance with special maintenance procedure (SMP) No. 779. In addition, the licensee performed a local leak rate test on the four valve The testing was also performed per procedure No. 779,

" Leak Testing of Steam Generator Level Isolation Valves Unit 1."

The licensee attempted to perform the test at 30 PSIG and 10 feet of water level at the outlet of the valves to simulate 10 feet of steam generator water level. On April i, 1987, the licensee performed a Type C test on the valves, but could only maintain 2 feet of water in the tygon tube connected at the outlet of the test rig. The result of the test at 30 psig was 89 standard liters per minute (SLM) with readings taken every 10 minutes. On April 8, 1987, the licensee performed a second test with an 8" diameter standpipe filled with 10 feet of water and connected to the outlet of the test rig. No problems were encountered during this test and the result was 88 SLM or 0.147 wt%/ da The licensee is limited to the Appendix J limit of <0.75Lt or

<0.212 wt%/ day leakage at the 95% upper confidence leve The Type A test result was 0.133 wt%/ day and adding the repair j and adjustment of the steam generator level isolation valves of 0.147 wt%/ day results in an as-found leakage rate, not including value lineup penalties, of 0.280 wt%/ da l This CILRT is the licensee's first failed test of Point Beach !

Unit l 6. Exit Interview The inspectors met with licensee representatives denoted in Paragraph 1 during the inspection at the conclusion of the inspection on April 10, 1987. The inspector summarized the scope end findings of the inspection. The licensee acknowledged the information and did not indicate that any of the information disclosed during the inspection could be considered proprietary in natur