IR 05000368/1985015
| ML20137G495 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/10/1986 |
| From: | Ireland R, Tapia J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20137G493 | List: |
| References | |
| 50-368-85-15, NUDOCS 8601210041 | |
| Download: ML20137G495 (6) | |
Text
_ _ _ _ _ _ _ _ _ _ -
__
-
.
-
o i
APPENDIX U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
NRC Inspection Report:
50-368/85-15 License:
NPF-6 Docket:
50-368 Licensee:
Arkansas Power & Light Company P. O. Box 551
!
Little Rock, Arkansas 72203 Facility Name:
Arkansas Nuclear One, Unit 2 Inspection At: ANO 2, Russellville, Arkansas and the NRC Region IV Office Inspection Conducted:
April 28-30 and October 28-30, 1985
///o/ir4 Inspector:
.
l h J. I. Tapia, Reactor Inspector, Engineering Date ve Section l
Approved:
aveeni i/fo /94, l
R. E. Ireland, Chief, Engineering Section Date Inspection Summary Inspection Conducted April 28-30 October 28-30, 1985 (Report 50-368/85-15)
Areas Inspected:
Special, announced inspection of the containment integrated leakage rate test.
The inspection involved 36 inspector-hours onsite and 20 in-office inspector-hours by one NRC inspector.
Results: Within the area inspected, no violations or deviations were identified.
.
..
-
.
.
~2-DETAILS 1.
Persons Contacted Arkansas Power and Light Company (AP&L)
D. N. Bennett, ILRT Director C. N. Shively, Plant Engineer L. J. Dugger, Instrumentation and Control Superintendent D. B. Lomax, Licensing Supervisor C. Halbert, Mechanical Engineering Supervisor R. Papini, Quality Control (QC) Inspector C. Taylor, Operations Technical Support T. Lloyd, Operations Shift Supervisor G. Wolfe, Operations Assessment Bechtel Engineering Corporation B. Patel, ILRT Test Director L. Young, ILRT Assistant Test Director K. Barry, Startup Engineer K. Pimentel, Data Technician 2.
Integrated Leak Rate Test (ILRT)
The periodic containment ILRT conducted using the Absolute Method as described in ANSI N45.4-1972, " Leakage Rate Testing of Containment Structures for Nuclear Power Plants," and ANSI /ANS-56.8-1981, " Containment System Leakage Testing Requirements," was addressed during this inspection.
The inspection involved procedure and records review, test witnessing and independent calculations by the NRC inspector.
This ILRT was conducted in accordance with approved procedures and satisfied the specified acceptance criteria contained in 10 CFR Part 50, Appendix J,
" Primary Reactor Containment Leakage Testing for Water Cooled Power Reactors," and in the Plant Technical Specifications.
a.
Procedure Review Engineering Test Procedure No. 2309.09, " Integrated Leak Rate Test,"
incorporates the referenced requirements and criteria.
This procedure was reviewed by the NRC inspector'and no discrepancies from the specified requirements and criteria were noted.
The review provided verification that the following test attributes were correctly addressed:
(1) Containment interior and exterior inspection requirements specifie,
_ _ _ _ _ _ _
- 4
..
-3-
. p>
(2)
Instrument locations justified by area surveys.
(3)
Instrument calibration requirements specified.
(4)
Instrument loss / test abort criteria delineated.
(5)
Instrument error analysis performed.
(6) Type B and C test results correction to Type A test results specified.
(7) Venting of internal isolated volumes required.
(8)
Isolation valve closing mode specified to be the normal mode.
(9) Proper postaccident system alignment to prevent creation of artificial leakage barriers specified.
(10) Quality control hold points specified.
(11) Test log entries required for repairs needed to complete test.
(12)Acceptancecriteriaspecified.
(13)Dataacquisitionrequirementsspecified.
(14)Dataanalysistechniquespecified.
(15) Hethod of despressurization specified.
As a result of the violation involving control of valve lineups during the December 1984 ILRT for ANO Unit 1(IR 313/8436), the ANO Unit 2 ILRT procedure was revised to ensure that any valve position and accompanying valve position tag changes are documented in the control room log sheets and approved by the ILRT test director, b.
Instrumentation The instrument calibration certifications traceable to the U.S.
,
!
National Bureau of Standards for the resistance temperature detectors, humidity measuring devices, pressure gauges, and the flowmeter used in the verification test were reviewed.
A multipoint calibration of all the instrumentation was performed. The guidelines of ANSI /ANS-56.8-1981, were used to select the instruments for the ILRT. The formula from the Instrumentation Selection Guide (ISG) was used during the ILRT to ensure that the data acquisition system
,
'
accuracy was sufficient to provide reliable test results. This i
.
$
%
..
m
.
..
.
.
.
.
.
.
.
.
.
.
.
..
.
.
...
-
m
.
.
.
.
-4-formula utilizes the systematic error of each sensor to determine an overall value for the data acquisition system.
The instrumentation system for the ILRT was based on a computer controlled data acquisition system capable of reading all sensors rapidly, storing the information and then outputting to the computer for conversions and calculation of the data.
c.
Test Witnessing The test pressure of 54 psig was reached at approximately 1:00 a.m.
on April 28, 1985.
At 6:30 p.m., the indicated leakage rate was 0.147%/ day, in excess of the acceptance limit of 0.075%/ day. Leakage into the steam generator was suspected and the secondary side was therefore, pressurized to 51 psig.
Subsequent computation of the leakage rate disclosed that the continuing excessive leakage could not be attributed to the steam generators.
The 51 psig secondary side block was subsequently removed.
Valve line-ups were also re-checked.
Closed loop systems penetrating containment were then addressed.
After closure of both sump valves it was determined that the sample return line in the postaccident liquid sampling system, installed in response to NUREG-0660, "NRC Action Plan developed as a result of the TMI-2 Accident," was not capable of withstanding containment accident pressure. This condition resulted from the inability of the two Target Rock Model No. 80-E-001 solenoid isolation valves to resist pressure in opposition to the normal flow direction into the containment sump suction line.
The valves were manually isolated and the test continued.
Modifications to correct the flow problem were to reverse the direction of both valves.
The results of the local leak rate tests which were performed after completion of the type A test were reviewed by the NRC inspector following the receipt of the licensee's final ILRT test report, as discussed in the following paragraph.
d.
Test Results Subsequent to the perfor. nance of the test, the NRC inspector obtained the raw data and computed the leakage rate in accordance with the Mast Point Data Analysis technique.
The computations performed were compared with the licensee's results for the purpose of verifying the calculational procedure and confirming the results.
This analytical technique confirmed the acceptability of the results obtained by the licensee.
The ANO - Unit 2 Primary Reactor Containment Integrated Leakage Rate Test Final Report dated August 19, 1985, provides a listing of the individual Local Leakage Rate Test (LLRT) results.
Whenever penetration configurations during an ILRT deviate from the ideal, the results of LLRTs for such penetrations must be added as a
_ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _
.__ _ _________________
?
-
.
.
!
-5-penalty to the ILRT results at the 95% upper confidence level.
An
,
'
acceptable penetration leakage penalty is determined using the
"minin;um pathway leakage" methodology.
This methodology is defined as the minimum leakage value that can be qualified through a penetration leakage path (e.g., the smallest leakage of the two valves in series).
This assumes no single active failure of redundant leakage barriers.
If penalties exist, they must be added to the upper confidence level of the ILRT results.
The "as found" condition of the containment is the condition at the beginning of an outage prior to any repairs or adjustments (ras) to
,
the containmeat boundary.
10 CFR 50, Appendix J, paragraph III.A.1 requires that during the period between the initiation of the containment inspection and the performance of the Type A test, no repairs or adjustments shall be made so that the containment can be tested in as close to the "as is" condition as practical.
ANSI N45.4-1972, paragraph 4.2 requires "For retesting, an initial record proof test shall be conducted at time periods and pressures established by the responsible organization, before any preparatory
,
repairs are made.
This will disclose the normal state of repair of the containment structure and a record of the results shall be retained." The NRC's position on the " initial record proof test" requirement is that it may be waived provided the Type A test results are back corrected for all ras to the containment boundary made prior to the performance of the Type A test.
If ras are made to the containment boundary prior to the Type A test, local leak rate tests must be performed to determine the leakage rates before and after the ras.
The as found Type A test results can then be obtained by adding the difference between the affected path leakages before and after ras to the overall Type A test results.
The as found leakage rate results are required and carry the same reporting requirements as the other Type A and Supplemental test results.
The correct methodology for correcting the Type A test results is the minimum pathway methodology.
The data providing the as-found and as-left values for the LLRTs were reviewed.
The following items were noted as a result of this review:
(1) The as-found leakage rates reported for the manually isolated Target Rock valves appear to be the as-left values since the leakage reported is small and is not indicative of the valves performance during the Type A test.
(2) The as found leakage for valve no. 2CCW-38 is listed as
" inoperative" and was not quantified and included in the summation for the as-found leakage.
The acceptance criteria of 0.60La for Type B & C tests was exceeded.
(3) The LLRT data reported for outage #3 (9/27/83-1/9/84) states i
_
_ _ _ _ - _ _ _ _ _ _ _ _ _ _
_ _ _ _
I
.
.
.
.
.
-6-that the "as-found leakage was unable to be determined."
It must be assumed that the acceptance criteria for the Type B & C tests was exceeded.
The identification of the as-found leakage of the Target Rock
valves at:d the failure to include this leakage as a penalty i
to the Type A results is considered an unresolved item (368/8515-01).
i The continuing failure to satisfy the 0.60La limit for r
penetration and isolation valve leakage may be indicative of inadequate corrective action taken by the licensee.
In order to resolve this matter, the licensee will need to provide a list of i
isolation valves that have been failing local leak rate tests at least 30% of the time, a summary of the corrective actions taken to correct the failures, and current plans to preclude the continuing failures of these valves.
Review of this information
t relative to the adequacy of past and planned corrective action is considered an unresolved item (368/8515-02).
l 3.
Exit Interview The NRC inspector met with licensee representatives at the conclusion of the inspection.
The NRC inspector summarized the scope and findings of the onsite inspection.
!
'
i L
(
t