IR 05000266/1986021
| ML20207L814 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 01/06/1987 |
| From: | Maura F, Mendez R, Ring M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20207L803 | List: |
| References | |
| 50-266-86-21, 50-301-86-18, NUDOCS 8701120357 | |
| Preceding documents: |
|
| Download: ML20207L814 (12) | |
Text
{{#Wiki_filter:. . U.S. NUCLEAR REGULATOR COMMISSION
REGION III
Reports No. 50-266/86021(DRS); 50-301/86018(DRS) Docket Nos. 50-266; 50-301 Licenses No. DPR-24; DRP-27 Licensee: Wisconsin Electric Power Company 231 West Michigan Milwaukee, Wisconsin 53203 Facility Name: Point Beach Units 1 and 2 Inspection At: Two Creeks, Wisconsin Inspection Conducted: September 26, through December 11, 1986 Inspectors: MkNz h /[6/77 Date /lflH Date % - A-Approved By: M.A. Ring,Chieh '/4[b Test Programs Section Dats Inspection Summary Inspection on September 26 through December 11, 1986 (Reports No. 50-266/86021(DRS); No. 50-301/86018(ORS)) Areas Inspected: Routine announced inspection by Region III based inspectors of the containment integrated leak rate test (CILRT) procedure, CILRT performance witnessing; CILRT results; local leak rate test (Type B and C) procedure and results.
NRC modules utilized during this inspection included 70307, 70313, 70323 and 61720.
Results: One violation was identified (failure to follow the requirements of Appendix J - Paragraph 7.a.(3)). , 8701120357 8701o7 gDR ADOCK 05000266 PDR i ! .
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- , . . -. -.. . . . _- . - -... -.. . . DETAILS 1.- Persons. Contacted . b . Wisconsin Electric Power Company
+*J. J. Zach, Manager +C. Krause, Senior Project Engineer + +*S. W. Pullins, ISI Engineer +A. Reimer,. Superintendent, Plant Engineer +*S.'R. Sherwood, Engineer, Nuclear +J. Knorr,-Regulatory Engineer
- F. A. Fluetje, Administrative Specialist i
' +R. Fromm, Modifications Engineer +D. Kohn, Engineer Bechtel Corporation )
- L.-Young, Engineering Specialist B. Patel, Engineering Specialist
R. Blum, Engineering Specialist ?Volumetrics,Inc.
D. H. Peyvan, Project Engineer ,.
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- Denotes persons attending the preliminary exit meeting of October 2, 1986.
+ Denotes persons in attendance during the telephone conference call of December 11, 1986.
, I The inspectors also contacted other licensee personnel including i members of the technical, operating and regulatory assurance staff.
2.
Licensee Action on Previous Inspection Findings ' a.
(0 pen) Open Item (266/84005-01): This item involved an inspector observation that the licensee had not established controls for the ' assignment of and changes to the weighting factors for the RTDs or dowcells.
During a review of the licensee's integrated leak rate test (ILRT) procedure, the inspector observed that assignment of and-changes'to the weighting factors were still not included in the ILRT l ' procedure.
The licensee personcel indicated they were in the
process of reviewing the matter but had not documented their proposed action to establish controls for the assignment of weighting factors.
, This item remains.open pending licensee action.
b.
(0 pen) Open Item (266/84005-02): This item involved inspector
determination that 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.
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_ . . The licensee indicated they had not established criteria to reject outliers, but would consider ANSI /ANS-56.8 as guidance.
This item remains open pending licensee action.
3.
Containment Integrated Leak Rate Test Procedure Review a.
Procedure Review The inspectors reviewed " Procedure for the Containment Integrated Leakage Rate Test Type ' A' Point Beach Nuclear Plant Unit No. 2," Revision 7, relative to the requirements of 10 CFR 50, Appendix J, ANSI N45.4-1972 and the FSAR.
All inspector comments were satisfactorily resolved.
b.
Clarifications of Appendix J Requirements To ensure the licensee's understanding of Appendix J requirements, the inspectors conducted numerous discussions with licensee personnel during the course of the inspection.
The following is a summary of the requirements discussed with the licensee.
(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 1.
Whenever this method is used BN-TOP-1 must be followed in its entirety except for any section which conflicts with Appendix J requirements.
(b) Total time (>24 hour duration test) using single-sided 95% UCL.
(c) Proposed Regulatory Guide MS 021-5, Regulatory Position No. 13.
If this method is utilized the licensee must submi' 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 Specifications.
(2) Periodic Type A, B, and C tests must include as-found results as well as as-left.
In order to perform Type B and C tests prior to a Type A, an exemption from the Appendix J requirement must be obtained from NRR.
The exemption request must state how the licensee plans to determine the as-found condition of the containment since local leak rate tests are being performed ahead of the CILRT.
An acceptable method is to commit to add any improvements in leakage rates, which are the results of repairs and adjustments (R&A), to the Type A test results using the " minimum pathway leakage" methodology.
This method requires that:
., ~ ... .. . - ' "-v ' (a) In the case where individual leak rates are assigned to . . two valves in series (both before and after the R&A), the ' penetration through' leakage would simply be the smaller of the two valves' leak rates.
(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 j
penetration through-leakage for each valve would be
50 percent of the measured leak' rate if both valves
are repaired.
. , '. (c). In the case where a leak rate is obtained by pressurizing between two isolation valves and only one valve is i 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).
l (3) Penetrations which are required to be Type C tested, as ! described in the FSAR and SER, must be vented inside and
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outside the 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 isolation valves to containment air test pressure.
, { The degree of draining of vented penetrations outside of ! 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 system.
. (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 penalty is determined'using
the " minimum pathway leakage" methodology.
This methodology l-is defined as the minimum leakage value that can be quantified through a penetration leakage path (e.g., the smallest leakage of 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 i upper confidence level of the CILRT results.
, (5) The start of the CILRT must be noted in the test log at the ! time the licensee determines that the containment stabilization j has been satisfactorily completed.
Reinitializing a test in j progress must be " forward looking," that is, the new start time must be the time at which the decision to restart is made.
, l This also implies that the licensee has determined that the F '
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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 a're: ' 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 open.
(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 begin.
(7) For the supplemental test, the size of the superimposed leak rate must be between 0.75 and 1.25 times 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 CILRT.
(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 rejection.
One example of an acceptable method for data outliers is described in an appendix to ANSI /ANS 56.8-1981.
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 sensor.
(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 the in
the loss of coolant emergency procedures.
! (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" method.
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 i ' to the better of the two leakage barriers in series when L performing Type B or C tests.
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. . (11) Test connections must be administrative 1y controlled to ensure their leak tightness or otherwise be subject to Type C testing. '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 reinstallation within the local leak rate testing procedure, and with a checklist prior to unit restart.
(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 site.
No violations or deviations were identified in this area.
4.
Containment Integrated Leak Rate Test Witnessing (Unit 2) a.
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.
_ Type Quantity RTDs
Dewcells
Pressure Gauges
Flowmeter
During the integrated leak rate test dewcell number 12 was deleted from the dan scan due to erratic (step changes) behavior.
The test data was reinitialized using the other 11 dewcells and the weighting factors were reassigned.
No other sensors or data sets were rejected during the test.
b.
Temperature Survey The inspectors reviewed the temperature survey performed by the licensee prior to containment pressurization.
The survey was performed with all containment fans off.
Both the survey, the CILRT, and the verification test were performed with the fans off.
The results of the temperature survey were satisfactory for
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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 subvolume.
c.
Witness of Test The inspectors witnessed the. reduced pressure CILRT on October 1, .1986, and noted that test prerequisites were met and that the appropriate revision to the test procedure was followed by test personnel.
Valve lineups for the following systems were verified to ensure that no fluid could enter the containment atmosphere and that adequate venting and draining was provided: System Penetration (s) Component Cooling to and from 1P1A 15 and 17 Component Cooling to and from IP1B 16 and 18 Service Air Supply to Containment 33C Hot Leg Sample 28A Pressurizer Steam Space Sample 28C Reactor Makeup Water to Containment 30C Nitrogen to Safety Injection Accumulators 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 identified.
5.
Test Results Evaluation a.
Reduced Pressure CILRT Data Evaluation Upon satisfactorily completion of the required stabilization period.
An'eight hour reduced pressure CILRT was performed at 45.2 PSIA during October 1, 1986, with data collected and reduced by the licensee every 15 minutes.
The inspectors independently monitored and evaluated leak rate and instrument performance.
There was agreement between the inspectors' and licensee's results as indicated by the following summary (units are in weight percent per day).
Measurement Licensee Inspectors Leakage rate measured 0.026 0.026 during ILRT (Ltm) Ltm at upper 95% 0.102 0.102 Confidence level Appendix J acceptance criteria at 95% UCL <0.75 Lt or <0.201 wt.%/ day.
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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 inspectors' independent readings and calculations) of 5.68 SCFM, equivalent to 0.268 weight percent per day (wt.%/ day) was induced.
Data was collected and analyzed by the licensee every 15 minutes.
The inspectors independently monitored and evaluated leak rate data to verify 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 0.312 0.312 during supplemental, Lc ! Induced leakage rate, Lo 0.268 0.268 Lc - (Lo + Ltm) 0.018 0.018 Appendix J acceptance criteria: -0.067 <[Lc-(Lo + Ltm)] <+0.067.
- As indicated above, the licensee's test verification resiilts were stable and within the acceptance criteria.
c.
CILRT Valve Lineup Penalties Due to penetration configurations which deviated from the penetration lineup requirement for the CILRT, the results of local leak rate tests for each penetration must be added to Ltm at the 95 percent UCL.
The following penalties must be added using the minimum pathway leakage for the following penetrations or possible sources of in-leakage: Local Leak Rate Based . ' On Latest Test (Units Penetration / Equipment are in SCCM) Service Air 495 Post Accident Containment Sampling Connection
Letdown 101 Seal Injection A
Seal Injection B
N Bottles and Accumulators 13,563
Containment Pressure Connection
Aux Charging
Charging
Total = 14,196 SCCM =.0237 wt.%/ day.
No violations or deviations were identified.
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As-Found Condition of CILRT Results The as-found condition is the condition of the containment at the beginning of the outage prior to any repairs or adjustments to the containment boundary.
Since the licensee performed the CILRT prior to repairs of the containment isolation valves and penetrations, the only adjustment was due to valve lineup penalties that deviated from the ideal.
The as-found Type A test result can then be obtained by adding the adjustments to the overall Type A test result.
The licensee is limited to the Appendix J limit of <0.75 Lt or <0.201 wt.%/ day leakage.
The following is a summary of the as-found containment leak rate (units are in weight percent per day): Measurement CILRT Valve Lineup Penalties 0.024 As-found Type A test results 0.102 Total As-found 0.126 The licensee passed this CILRT in the as-found condition.
6.
Local Leak Rate Test Review The inspector reviewed local leak rate test Procedure No. 0I-58, Revision 7, " Leak Testing of Containment Isolation Valves Units 1 and 2 General Instructions and Information," for testing method, acceptance criteria and penetrations to be tested.
The inspector also reviewed and verified the containment local leak rate test program to determine whether the sum of LLRT results met the acceptance criteria (<0.6 La or <231,000 SCCM).
In addition, the inspector verified that penetrations and containment isolation valves were tested at the required frequency and that measuring and that equipment was calibrated at the required intervals.
The following set of local leak rate tests results were reviewed: Unit Refueling Outage Date When Performed
10 December 1982
9 April 1983
11 August 1983
10 October 1984
12 September 1984
11 November 1985
13 June 1986 During the review of the local leak rate test (LLRT) results, the inspector observed that measuring and test equipment identification numbers were not documented on LLRT results.
The licensee currently uses three leak rate indicators which have different ranges but overlap at the lower and higher readings. The serial number and the ra;ge of the leak rate indicators are as follows: (1) No. TIS-1008A, from 0 to 2 standard l l
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.: I ^ liters per minute (SLM), (2) No. TIS-1012 has three ranges, from 0.02 to 0.2 SLM, 0.2 to 2 SLM, and 0-20 SLM and (3) No. TIS-10088, from.0 to . - 400 SLM. -The inspector reviewed records to determine whether out of cal.ibration test equipment was being reported to the leak rate testing department and whether the LLRT results were being adjusted to account for the as-found calibration errors.
Although no problems were found in this area, the inspector was concerned that' erroneous LLRT corrections could. occur since the range and test equipment were never documented. On September 30, 1986, the licensee issued an internal memo instructing all personnel performing local leak rate tests to document the' test equipment used and the range.
This item.is open pending review of future LLRT results.
(266/86021-01; 301/86018-01).
7.
Review of Previous CILRT Results a.
The inspectors' reviewed the results of previous CILRTs as presented by the licensee in their reports to the NRC.
The reports reviewed and the conclusions reached by the inspectors were discussed with the licensee and are as follows: ' (1) Unit No. 1 October 1981 CILRT The calculated leakage rate at the 95% UCL was 0.068 wt.%/ day.
According to the report nine penetrations were not in the ideal test configuration, therefore requiring a penalty to be added to the CILRT results.
It also indicates that repairs and adjustments'were made prior to the Type A test..The values given for those nine penetrations before repairs was 149,058 scc / min or 0.758 wt.%/ day and after repairs was 4,064 scc / min' or 0.027 wt.%/ day.
Based on the results'given in the report the as-found containment leakage rate was 0.799 wt.%/ day and the as left containment leakage rate was 0.095 wt.%/ day.
The acceptance criteria = 0.75 Lt = 0.212 wt.%/ day.
The Type A test was a failure in the as-found condition.
(2) Unit No. 2 April 1982 CILRT The calculated leakage rate at the 95% UCL was 0.072 wt.%/ day.
According to the report eleven penetrations were not in the ideal test configuration, therefore requiring a penalty to be added to the CILRT results.
It also' indicates that repairs and adjustments were made prior to the Type A test.
The values given for those eleven penetrations before repairs was 126,462 sec/ min or 0.147 wt.%/ day'and after repairs was 1,471 scc / min or 0.002 wt.%/ day.
Based on the results given in the report the as found containment leakage rate was 0.217 wt.%/ day and that as left containment leakage rate was 0.074 wt.%/ day.
The acceptance criteria = 0.75 Lt = 0.201 wt.%/ day.
The Type A test was a failure in the as found condition; however, since the test just concluded (October 1986) was successful in the as-found condition the results of the 1982 CILRT will have no effect on future test frequency.
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4- . , L -{ ~ (3) Unit No.~1' April 1984 CILRT.
. The calculated leakage rate, Ltm, was 0.186~wt.%/ day with a ~ 95% UCL of 0.202 wt.%/ day, adjusted for.the PORV N bottles
leakage. The superimposed leakage rate, Lo, during the supplemental _ test was 0.147 wt.%/ day.
The measured leakage rate, Lc, during the supplemental test, adjusted for the PORV N bottles leakage, was 0.234 wt.%/ day.
10 CFR 50, Appendix J, 2requires.that a Type A text be verified by a supplemental test of sufficient duration to establish accurately.the change in leakage between the Type A test and the supplemental test, and that for the results to be acceptable the differenta between the two tests can not exceed 0.25 Lt.
In this case, the ~ difference between the Type A test and the supplemental test .was: Ltm - (Lc - Lo) = 0.186-(0.234 - 0.147) = 0.099 wt.%/ day.
Since 0.25 Lt = 0.053 wt.%/ day, the results of the supplemental test were not acceptable.
Appendix J requires that if the results of the supplemental N test are not within 0.25 Lt, the cause must be determined, corrective action taken, and a successful test performed.
The m ^' report-shows that the data was misinterpreted by the licensee ~; which resulted in a failure to realize that the supplemental test had failed.
As a result, no cause of failure was
determined, no corrective action was taken, and a successful ' " supplemental text was never performed.
This is a violation-(266/86021-02) of 10 CFR 50, Appendix J.
Since the supplemental test failed to verify the accur'acy of the Type A test, the inspectors find the entire 1984 CILRT-invalid. A review of the CILRTs performed during the present ten year service period showed that three tests will have been performed once the licensee conducts the CILRT scheduled for April 1987; therefore meeting Appendix J requirements.
A-review of Technical Specifications requirements for containment integrity showed no coupling of the testing frequency with the definition of containment integrity. As a result, the voiding i of the April 1984 CILRT did not place Unit 1 in violation of containment integrity, i b.
During the recent interview of December 11, 1986, the licensee i expressed disagreement with the Region III position regarding the April 1984 Unit 1 test.
In addition, the licensee stated that the results presented for the penalties taken on the 1981 (Unit 1) and 1982 (Unit 2) tests had been calculated using the maximum leakage pathway method.
The inspector stated that the licensee should recalculate the penalties using the minimum leakage pathway method and correct the reports submitted.
This matter is open pending review of the licensee's local leak rate , l test data (266/86021-03; 301/86018-02).
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Open Ite71 Open itsis<are matters which have been discussed with the licensee, which will be reviewed by the inspector and which involve some action on the paat of the NRC or licensee or both. Open items disclosed during the inspection are discussed in Paragraphs 6 and 7.b.
9.
Exit Interview The inspectors met with licensee representatives denoted in Paragraph 1 during the inspection on October 2, 1986 and again by telephone at the conclusion of the inspection on December 11, 1986.
The inspectors summarized the scope and 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 nature.
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