IR 05000259/1990035
| ML18033B587 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/12/1990 |
| From: | Belisle G, Whitener H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18033B586 | List: |
| References | |
| 50-259-90-35, 50-260-90-35, 50-296-90-35, NUDOCS 9012270006 | |
| Download: ML18033B587 (15) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323 Report Nos.:
50-259/90-35, 50-260/90-35, and 50-296/90-35 Licensee:
Tennessee Yalley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.:
50-259, 50-260 and 50-296 License Nos.:
DPR-33, DPR-52, and DPR-68 Facility Name:
Browns Ferry 1, 2, and
Inspection Conducted:
October 22-26 and November 5-9, 1990 Inspector:
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Approved by:
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>s e, se'est Programs Section Engineering Branch Division of Reactor Safety
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)gne SUMMARY Scope:
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This routine, announced inspection was conducted in the areas of containment local leak rate testing, changes to the leak rate test program and LER followup inspection.
Results:
The 'licensee's local leak rate (LLRT) test program was found to meet NRC requirements.
Detailed test procedures and controls have been developed and implemented accordingly.
Leak rate tests for the suppression pool spray isolation valves were witnessed.
Conservative leak rate test practices were being followed and test personnel appeared knowledgeable of test requirements and the use.of test instrumentation.
The following two strengths were identified in the LLRT program:
Detailed penetration draining instructions were incorporated into each procedure, paragraph 3.b.
Supplemental tests were incorporated to assure testing of bonnets and packing seal leakage, paragraph 3.d.
9012270006 901214 PDR ADDCK 05000259
One weakness was identified in the LLRT program.
The licensee has not classified a single remote manual valve in the jet pump sample line as a
conta'inment isolation valve.
The licensee has agreed to further evaluate the
. status of this valve, paragraph 3.d.
In the areas inspected, violations or deviations. were not identifie REPORT DETAILS Persons Contacted Licensee Employees
- S. Austin, Engineer, Compliance Licensing
- K. Clark, Supervisor, Containment Programs and Test, Corporate Maintenance J. Mantooth, Work Control, Maintenance
- C. Hiller, Mechanical Engineer, Corporate Maintenance G. Morrison, Compliance Licensing
- L. Myers, Plant Manager
- F. Nilsen, Mechanical Engineer, Engineering Support J. Schlessel, Maintenance
- J. Shaw, Supervisor, Engineering Support Other licensee employees contacted during this inspection included craftsmen, engineers, mechanics, technicians, and administrative personnel.
NRC Resident Inspectors
- W. Bearden, Resident Inspector D. Carpenter, Senior Resident Inspector
- E. Christnot, Resident Inspector
- K. Ivey, Jr., Resident Inspector
- C. Patterson, Restart Coordinator
- Attended exit inter view Acronyms and initialisms used. throughout this report are identified in the last paragraph.
Purpose The purpose of this inspection was to verify the development and implementation of programs, controls, procedures, and test activities which ensure that containment local leak rate testing (Type B and C) is performed consistent with the requirements of the TS, Appendix J of
CFR 50, and applicable industry standards.
Containment Local Leak Rate Testing (61720, 61715)
a.
Administrative Procedures An important part of monitoring and maintaining containment integrity is the periodic testing performed to verify the leak tightness of containment leakage barriers.
As part of the evaluation of containment local leak rate testing, the inspector reviewed the
formal procedures established by the licensee to verify local leak tightness of leakage barriers.
The following documents were reviewed either totally or in part to verify that the licensee established adequate procedures and controls.
Procedure Revision Title SDSP 17.1 SDSP 6.7 SDSP 7.6
Primary Containment Leak Rate Test Requirements Post Maintenance Test Program Maintenance Management System SDSP 7.9
Integrated Schedule and Work Control MNI 51 PHI 17.1
10 Maintenance of CSSC/non-CSSC Valves and Flanges, Units 1, 2 and
Conduct of Testing The above documents were reviewed in general for assignment of responsibility; definition and control of processes including identification and tracking pre/post maintenance testing; adequate program instructions controlling leakrate test activity; and, identification of LLRT program scope and components.
Based on the review of portions of these procedures, the inspector concluded that the licensee has developed administrative procedures necessary to define the LLRT program, to control LLRT activities, and to provide for control of pre/post maintenance leak rate testing in conformance with the TS and Appendix J to
CFR 50.
b.
Test Procedures SDSP-17.1 defines the scope of the LLRT program.
This document, which was devel.oped by system walkdowns and design dr awing reviews to identify all containment penetrations and penetration components, is the basis for the LLRT surveillance program.
The LLRT program consists of 95 SIs organized as follows:
SI-4.7.A.2. i-3/seri es:
SI-4.7.A.2.g-1:
SI-4.7.A.2.g-2/series:
Series of SIs for leak rate testing mainsteam system valves Containment Airlock leak rate tests Series of SIs for Type B leak rate testing including electrical penetra-tions, hatch seals, and bellows
SI-4.7.A.2.g-3/ser ies:
Series of SIs for Type C leak rate testing of CIVs SI-4;7.A.2.g-4A:
SI-4.7.A.2.g-48:
Leakage control procedure used for tabulation of all Type
and Type C
tests to verify that leakage is within regulatory limits Option to SI-4.7.2.g-4A used when only limited leak rate testing is to be performed The inspector reviewed leakage control procedures and a
representative sample of surveillance instructions for leak rate testing 16 penetrations for the assignment of responsibility, control of test activity, and technical content.
In this review the inspector confirmed the following conditions:
(I)
Containment pressure boundaries and containment isolation valves were incorporated into the test program as defined in SDSP-17. 1.
(2)
Control procedures provided for the summation of Type 8 and C
"As Found" and
"As Left" maximum pathway leakage rates.
(3)
Test procedures specified correct test pressure, approved test methods, appropriate calculations, and acceptable leak rate limits.
(4)
Test procedures provided adequate valve identification for test connections, vents, drains, and block valves.
(5)
Test procedures contained adequate detailed instructions for penetration draining and valve alignment for testing.
(6)
Test procedures in conjunction with the administrative controls provided adequate instruction for pre/post maintenance leak rate testing.
In the detailed review of the 16 SIs, the inspector compared penetration draining instructions with isometric drawings and vent path and test valve configurations with up to date system drawings.
From this comparison the inspector concluded the procedural valve alignments were adequate for draining, venting and testing. 'he detailed draining instructions were considered to be a strong point in the procedures.
Observations and Test Results In addition to reviewing the leak rate test program documents and test procedures, the inspector witnessed the performance of the local leak rate test on the suppression pool spray isolation valves
(2-SI 4.7.A.2.g-3/74e).
The inspector verified that an approved, current procedure
'was used, equipment
.was in calibration, test personnel were familiar with the test equipment and knowledgeable of the procedure and test requirements.
Review of test results indicated that local leak testing is about
percent complete and results were well below the allowable leakage.
These results showed that where leakage exceeded the test procedure acceptance limit for a penetration, repairs were made and a post maintenance test was successfully performed.
The acceptance leak rate specified in the procedures for'ach penetration was set so that if each penetration meets the acceptance limit, the summation of all Type B and C tests would meet the regulatory leak rate of. 0.6La.
The inspector considered the basis for-the acceptance criteria adequately conservative.
The licensee established the official starting date for the local leak rate testing as July 30, 1990.
Subsequent to this date and prior to the need to establish containment integrity, all Type B
and C testing will be completed.
If plant start-up is delayed, test updates will be performed to ensure that test validity spans the anticipated operating cycle.
Action to Upgrade LLRT Program In 1985 the licensee identified and reported certain valves that were not leak rate tested in accordance with 10 CFR 50, Appendix J (see Paragraph 4).
Since that time, all three units have remained shutdown and a
complete program review performed.
A number of actions have been taken to bring the LLRT program in line with Appendix J as a result of this program review.
-
The inspector reviewed 12 design change requests for plant modifications, verified that the modifications are complete and verified that surveillance instructions have been approved to incorporate the changes into the LLRT program.
The nature of these changes can be characterized as follows:
(I)
Installation of block valves, drain valves, vent valves and test connections to enable isolation valves to be tested in the accident direction and to facilitate testing bonnet and packing seals.
(2)
Addition-of stainless steel overlay to improve valve performance.
(3)
Reorientation of valves in line so that the valve packing and bonnet seals are in the test boundary.
(4)
Cut and cap a
system no longer used to remove potential leak path (5)
Change valve type to improve leak tight design.
In addition to the changes made to conform with Appendix J
requirements, the licensee developed supplemental testing techniques for certain valves to meet these requirements.
These techniques included:
( I)
Breaking a line at a joint and installing a test flange to test valves in the accident direction.
(2)
Installation of an airtight box around a valve to pressurize bonnet and packing seals.
(3)
Use of packing leak off lines to check packing leakage.
(4)
Use of quarterly ISI pressure test for certain water sealed valves to verify bonnet and packing integrity.
The inspector concluded that through plant modifications and innovative testing techniques, the licensee developed the means to meet Appendix J
requirements.
The inspector considered the supplemental te'sting techniques a strength which enhances the quality of the LLRT program.
The inspector also reviewed some aspects of the post accident sample system plant modification to meet NUREG-0737 requirements.
Specifi-cally, the inspector reviewed this modification from a containment isolation aspect.
The RHR system and containment atmosphere sample lines and return line appear to be adequate.
Double isolation valves are provided for these lines.
However, the inspector identified a
concern related to a core )liquid sample line which utilizes a jet pump instrument line as the flow path and has only one remote manual solenoid valve (FSV 43-70) in the line.
The modification involves taping off of the jet pump instrument line between the excess flow check valve and the flow transmitter and routing the sample line to the sample analyzer.
Since this sample line is intended to be used for small break conditions, the line will be water filled and reactor system pressure of 1000 psi will be available to activate the excess flow check valve in the event of a
sample line rupture to prevent excessive loss of primary system water.
The licensee consequently does not consider valve FSV 43-70 as a containment isolation valve in the Appendix J
program.
The inspector reviewed the operating conditions and determined the following:
(I)
Under small break LOCA conditions, the excess flow check valve will close and limit loss of reactor coolant inventory.
(2)
Valve FSV 43-70 is normally closed and provides a
passive barrier except when opened for taking a sample.
(3)
A sample will be taken at six month interval For the conditions of a
small break LOCA, the excess flow check valve will function to limit the loss of reactor coolant inventory should a
leak occur while FSV 43-70 is open to 'collect a sample.
When no sample is being collected',
FSV 43-70 is closed and remains normally closed to form a passive isolation barrier.
However, these conditions change for a DBA LOCA.
In the DBA LOCA reactor system pressure is insufficient to close the excess flow check valve.
Since the sample loop outside containment is not a
fully qualified closed system, the only remaining containment isolation leakage barrier is FSY 43-'70.
The licensee stated that in a
DBA LOCA, the reactor coolant sample will be obtained through the RHR sample line and FSV 43-70 will remain closed as a
passive containment leakage barrier.
Based on the these conditions, the inspector concluded that FSV 43-70 is a containment isolation valve subject to
CFR 50, Appendix J leak rate requirements.
Some supplemental actions to assure the effectiveness of FSV 43-70 as a
passive containment isolation barrier were discussed with licensee management at the exit interview.
Some of the actions discussed with the licensee included the following:
(I)
Deactivate the valve in its closed position to prevent inadvertent opening in a DBA condition.
(2)
Incorporate a statement in the EOI defining specific conditions under which the valve may or may not be opened.
(3)
During the sample test, each six months perform a'ystem walkdown to verify the leak tight integrity of the sample loop at reactor system pressure.
(4)
Include the valve (FSV 43-70) in the Appendix J LLRT program.
Under these conditions the integrity of the isolation valve and the sample loop would be periodically confirmed and provide reasonable assurance of containment integrity under DBA conditions.
Licensee management agreed to further evaluate the status of FSV 43-70.
In line with the above inspection, the inspector also reviewed the valves which are reverse tested to determine if these tests are as conservative as a test in the accident direction.
Reverse tests were examined in the main steam, ventilation, control air, HPCI, RCIC,
.
The inspector concluded that based on plant design and supplemental test techniques, the reverse tests were acceptabl LER 259/85008 (92701)
On March 15, 1985, the licensee reported that the Unit
HPCI and RCIC turbine exhaust valves (HVC 73-23 and HCV 71-14), the HPCI turbine exhaust drain valve (HCY 73-24)
and the RCIC turbine condenser vacuum pump discharge valve (HCV 71-32)
have flanged bonnets exposed to containment air pressure which were not leak rate tested.
This condition also existed in Units
and 3.
This problem led to identification of other test deficiencies and prompted the licensee to perform an overall review of local leak rate testing for all three units.
Based on the review of plant modifications and.test methods during this inspection, the inspector determined that the reported conditions were corrected for Unit 2.
Also, the same modifications and test methods will be implemented prior to subsequent Unit 1 or Unit 3 start up as a result of the LLRT program review.
This LER is considered closed.
Exit Interview The inspection scope and results were summarized on November 9, 1990, with those persons indicated in paragraph 1.
The inspector described the areas inspected and discussed in detail the inspection results listed below.'roprietary information is not contained in this report.
Dissenting comments were not received from the licensee.
Program strengths involved the development of detailed penetration draining instructions in the procedures and supplemental tests for bonnet and packing seals which enhance the quality of the leak rate program.
One weakness involved failure to classify a sample line isolation valve as a containment isolation valve.
Acronyms and Initialisms CI V CSSC CS DBA EOI HPCI ISI LER LLRT LOCA MMI PMI PSI RCIC RHR SDSP SI TS Containment Isolation Valve Critical Structures Systems and Components Core Spray Design Basis Accident Emergency Operating Instruction High Pressure Coolant Injection Inservice Inspection Licensee Event Report Local Leak Rate Test Loss of Coolant Accident Mechanical Maintenance Instruction Plant Manager Instruction Pounds Per Square Inch Reactor Core Isolation Cooling Residual Heat Removal Site Director Standard Practice Surveillance Instruction Technical Specification
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