ML20207L814
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| 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 | |
| Download: ML20207L814 (12) | |
See also: IR 05000266/1986021
Text
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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
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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)).
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8701120357 8701o7
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DETAILS
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1.- Persons. Contacted
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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
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*F. A. Fluetje, Administrative Specialist
+R. Fromm, Modifications Engineer
+D. Kohn, Engineer
Bechtel Corporation
) *L.-Young, Engineering Specialist
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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.
Licensee Action on Previous Inspection Findings
2.
'
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
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-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 4
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:
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' (a) In the case where individual leak rates are assigned to
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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.
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(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
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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
- ' outside the containment during the CILRT. All vented
penetrations must be drained of water inside the containment
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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
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standards comparable to those required for a seismic system.
(4) Whenever penetration configurations during a CILRT deviate from
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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
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failure of redundant leakage barriers. Additionally, any
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increase in containment sump, fuel pool, reactor water, or
- suppression pool level during the course of the CILRT must be
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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 results.
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(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.
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This also implies that the licensee has determined that the
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i. 1 , test has failed,'and has enough data'to quantify the leakage
, , . rate. 'Any deviation from these positions should be discussed,
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'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
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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
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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 i '
of two valves in series). This assumes a single active failure
to the better of the two leakage barriers in series when
L performing Type B or C tests. i i 5
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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 24
Dewcells 12
Pressure Gauges 2
Flowmeter 1
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
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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.
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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:
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Local Leak Rate Based
On Latest Test (Units
Penetration / Equipment are in SCCM)
Service Air 495
Post Accident Containment Sampling Connection 0
Letdown 101
Seal Injection A 6
Seal Injection B 1
N2 Bottles and Accumulators 13,563
Containment Pressure Connection 0
Aux Charging 28
Charging 2
Total = 14,196 SCCM = .0237 wt.%/ day.
No violations or deviations were identified.
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d. 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
1 10 December 1982
2 9 April 1983
1 11 August 1983
2 10 October 1984
1 12 September 1984
2 11 November 1985
1 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
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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
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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:
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(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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~ (3) Unit No.~1' April 1984 CILRT.
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. The calculated leakage rate, Ltm, was 0.186~wt.%/ day with a
95% UCL of 0.202 wt.%/ day, adjusted for.the PORV 2N 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
N2 bottles leakage, was 0.234 wt.%/ day. 10 CFR 50, Appendix J,
requires.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
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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
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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 #
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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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8. 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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