ML20154K397
| ML20154K397 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 08/23/1988 |
| From: | Maine Yankee |
| To: | |
| Shared Package | |
| ML20154K375 | List: |
| References | |
| NUDOCS 8809260006 | |
| Download: ML20154K397 (31) | |
Text
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ENVIRONMENTAL QUALIFICATION.
ENFORCEMENT CONFERENCE AUGUST 23, 1988 YANKEE ATOMIC ELECTRIC COMPANY
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EQ ENFORCEMENT CONFERENCE TABLE of CONTENTS INTRODUCTION AND PROGRAM OVERVIEV I.
Scope of Enforcement Conference II.
EQ Program Overview III.
Program Status EQ IMPLEMENTATION MILESTONES AUDIT ITEM 50-309/87 16-19, DISCUSSION CHARCING PUMP SUCTION LINE VENT ISOLATION VALVES, DISCUSSION
SUMMARY
OVERH EADS (q
J Introduction / Overview Program Status Commitment to Implementing and Maintaining High quality EO Program Topic History Cabic (nd Terminal Block Qualification Charging Pump Suction Line Vent Isolation Valve Figure 1, Vent Isolation Valves Location Vent Isolation Valves Flow Diagran Summary O
INTRODUCTION AND PROGRAM OVERVIEW I.
SCOPE OF ENFORCEMUlT CONFERENCE o
This enforcement conference addresses three EQ issues identified by Maine Yankee. These are:
l l
A.
Audit Ite '^ 509/87-16-13 l
Qualification of four cables associated with reactor coolant I
hot and cold leg RTDs and qualification of one terminal block in cold leg RTD (LER-87-005-00);
Qualification of two terminal blocks for containment sump level instrument circuits (LER-87-005-00);
B.
LER 88-005-00 and LER-88-005-01 O
ce 11fic tie er feer ete# eta-ever ted vetves oe the HPSI/ charging pump suction vent.
o In summary, these issues do not warrant escalated enforcement action l
under the Modified Enforcement Policy (Generic Letter 88-07).
II.
EQ PROGRA?) OVERVIEW o
NRC originally established equipment qualification requirements in 1979 with IE Bulletin 79-018. The final EQ rule became effective on February 1, 1983, establishing a deadline for licensee compliance of November 30, 1985. Throughout the history of evolving requirements in this area, Maine Yankee has exerted substantial efforts to meet
. applicable requirements.
o, the Program Overview, lists the chronology of efforts by Maine Yankee.
O 6748R/4.425
Maine Yankee continues to be pro-active on equipment qualification by o
(q implementing activities to enhance and maintain the program.
_j Maine Yankee has also been prompt in responding to new industry o
concerns identified in IE notices and bulletins, and has remained informed of new issues and developments through participation in industry groups (i.e., NUGEQ, EPRI, IEEE) and through a strong utility network.
III. PROGRAM STATUS o
The potential EQ deficlincies that have been identified by Maine Yankee, and which are the subject of this enforcement conference, were not indicative of programmatic or management weaknesses.
o The potential deficiencies represent only 11 items (4 cables, 3 terminal blocks, and 4 SOVs). This is out of approximately 200 primary components on the EQ Master List, which encompasses an
()
estimated 1500 individui.1 itcms (i.e., splices, cables, terminal blocks, etc.).
o Maine Yankee has a high degree of confidence that deficiencies identified are isolated occurrences based on specific root causes.
o As discussed further below, Maine Yankee has also concluded that the items identified as potential deficiencies were in facts a.
potentially qualifiable, b.
not EQ deficiencies, or c.
not significant from a safety perspective.
o In summary, the current status of the items is as follows:
The cables for the reactor coolant hot and cold leg RTDs have been replaced with qualified cable and the terminal block was
()
removed as part of the aforementioned cable replacementt 6748R/4.425
The terminal blocks for containment sump level instrument
()
circuits have been replaced by qualified Raychem splices; Design codifications are being implemented such that the four solenoid valves do not need to be included in the EQ Master List.
As reflected in this status, Maine Yankee has taken prompt measures o
to ensure that underlying concerns are addressed and that appropriate qualification is maintained.
In several cases. Maine Yankee has taken actions which reflect its overall philosophy that it is preferable to make hardware changes to address an issue than to spend the same resources on analysis to demonstrate that equipment was qualified or qualifiable, o
The Maine Yankee EQ Program was and is in good condition. Maine Yankee believes that at all times the plant has been safe to operate. The company remains committed to further improvement in the EQ area to keep abreast with the evolving state of industry and NRC
()
knowledge.
O 6748R/4.425
PROGRAM OVERVIEW O
MAINE YANKEE HAS EXERTED SUBSTANTIAL EFFORTS TO IMPLEMENT PROGRAM AND MEET EQ DEADLINFA AS SHOWN BELOW:
YAEC Report No.1180, "Environmental Qualification of June 15, 1973 Electrical Equipment Within the Reactor Containment at Maine Yankee Atomic Power Station" YAEC Report No. 1217, "Environmental Qualification of i
June 2, 1980 I
Safety-Related Electrical Equipment at Maine Yankee Atomic Power Company" was submitted and superseded Report l
j No. 1180.
l l
YAEC Report No. 1229, "Environmental Qualification October 31, 1980 of Safety-Related Electrical Equipment" was submitted in response to Staff Order CLI-80-21.
Maine Yankee received NRC - Safety Evaluation Report June 1, 1981 (SER) which included NRC Technical Evaluation Report (TER).
O September 2, 1981 YAEC submitted additional information in response to NRC's SER and TER.
NRC issued SER which included Franklin Research Center April 8, 1983 (FRC) TER.
Information requested by 10CFR50.49 was submitted to May 20, 1983 NRC.
Meeting with NRC to resolve FRC TER concerns.,
April 4, 1984 HYPAC to NRC, "Certification of Compliance to 10CFR50.49."
January 25, 1985 I
NRC Region I EQ Inspection of Maine Yankee.
Ju?y 20-24, 1987 NRC issued EQ Inspection Report No. 50-309/87-16.
November 19, 1987 O December 22, 1987 Maine Yankee submitted "Reply to Notice of Violation" in responso to EQ Inspection Report No. 50-309/87-16.
l
AUDIT 17EM NO.: 50-309/87-16-13 7(_/
AUDIT ITEM DESCRIPTION: Qualification of Weidmuller Terminal Blocks for Containment Sump Level Instrument Circuits, Continental Cables for Reactor Coolaat Hot and Cold Leg RIDS, and States Terminal Block for Reactor Coolant Cold Leg RTD.
I.
AFFECTED EQUIPMENT / SYSTEMS o
LT-307K Containment Sump Level Transmitter o
LT-308K Containment Sump Level Transmitter o
TE-121X Reactor Coolant System Hot Leg Temperature Detector o
TE-121Y Roactor Coolant System Cold Leg Temperature Detector o
TE-131X Reactor Coolant System Hot Leg Temperature Detector o
TE-131Y Reactor Coolant System Cold Leg Temperature Detector II.
IDENTIFICATION AND RESPONSE o
Continental cables in RCS Loops 2 and 3 (both hot and cold legs) and a States terminal block in RCS Loop 2 (cold leg) were identified as a result of a plant walkdown and EQ maintenance
/~3 activities during the 1987 outage.
In addition, Weidmuller
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terminal blocks were identified in two containment sump level transmitter circuits as a result of the same walkdown.
o Corrective action was taken to replace the Continental cables with qualified Brand-Rex cable on June 10-18, 1987.
The States terminal block was removed as a result of the aforementioned cable replacement. The Weidmuller terminal blocks were replaced with qualified Raychem splices on June 3-15, 1987.
o An extensive review of the EQ diagrams versus Maine Yankee electrical drawings (FE Series) was conducted during the 1987 outage to ensure that the EQ diagrams concurred with the plant as-built drawings.
o The NRC was notified of the discrepancies per LER 87-005-00 on June 25, 1987.
III.
SAFETY SIGNIFICANCE EVALUATION A.
Containment Sump Level Transmitters o
Maine Yankee has concluded that the Weidmuller terminal blocks were qualifiable. Qualification documentation was on file at Maine Yankee for containment use of Weidmuller terminal blocks prior to their identification in the containment sump level O
transmitter circuit.
1-1 6745R/12.580
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A review utilizing the conservative Main Steam Line Break temperature profile with the Weidmuller terminal block O
Insulation Resistance (IR) test data determined that the containment sump level accuracy would not have been seriously affected by the decreased terminal block resistance. The l
review concludes that errors are insignificant throughout the l
entire operational range of the transmitter (0.16 inches at zero level and less when the sump is full). These errors would not have affected operator response since these instruments are used in conjunction with the RWST level transmitters.
o The containment sump level transmitters are utilized in conjunction with the RWST level transmitters to verify sump level prior to automatic initiation of recirculation. The i
Maine Yankee Emergency Operation Procedures require operator action to ensure correct valve alignment based on sump and RWST levels.
B.
Reactor Coolant System Hot and Cold Leg RTDs o
The qualification of the Continental cables and States terminal block had been documented for EQ applications prior to their being identified in the RTD circuits. A Continental cable Qualification Documentation Review (QDR) package had been developed for outside containment use. The QDR was void since this cable was determined not to be in use in EQ applications at the time the cables were identified.
Note that this voided QDR had been previously reviewed by the i
FRC for use outside containment instrument applications.
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The States terminal block was qualified prior to being identified in the Reactor Coolant System cold leg circuit. As in the case of the Continental cable, the qualification was based on outside containment parameters.
i o
The operational requirements for the Reactor Coolant System hot j
and cold leg RTDs has determined that these components would not be required for a design-based LCCA. The RTDs are utilized in the event of a small break LOCA or Main Steam Line Break.
I o
The RCS hot and cold leg RTD1 provide' data to the operator for J
verification of natural circulation.
The hot and cold leg RTDs are two of five parameters which the operator will utilize to verify natural circulation; the others are incore thermocouples, pressurizer pressure transmitters, and steam generator pressure transmitters, o
The reduced Insulation Resistance (IR) which could result at j
high temperatures would cause the cold and hot leg indication to read low. One set of RTDs (Loop 1, both hot and cold legs) was fully qualified and documented. The operators would tend to utilize the highest temperature which is located in the O
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1-2 6745R/12.580 i
o The RCS hot and cold leg RTDs are also utilized to monitor long r's term RCS temperature as part of Maine Yankee Regulatory
(_)
Guide 1.97 commitments.
In the long term, containment temperatures would be below the maximum MSLB temperature.
Since cable and terminal block IR values are inversely related to the ambient and conductor temperature, the potential inaccuracy would decrease as containment temperature decreases. Over the long term, it is our engineering judgement that the hot and cold leg RTDs would perform their intended function.
IV.
CLEARLY SHOULD HAVE KNOWN ANALYSIS o
At the time of the Weidmuller terminal block identification, Maine Yankee had on file a Qualification Documentation Review (QDR) package. This package supported the use of the terminal blocks in the containment sump level transmitter circuits.
o At the time of the Continental cable ider
'ication, Maine Yankee had a QDR on file. This QDR had been v* ded because it was assumed the Continental cable was not utilized in instrument applications.
o At the time of the States terminal block identification, Maine Yankee had a QDR on file.
Although this package did not support terminal block use with instruments inside containment, it is felt with reasonable assurance that qualification could have been substantiated.
o Maine Yankee personnel performed a walkdown to verify EQ Diagrams in 1984. The subject Weidmuller terminal blocks, Continental cable and States terminal block were not identified during this walkdown. Another walkdown was performed in accordance with a written procedure during the 1987 outage. The terminal blocks and cables were discovered as a result of this walkdowa.
o IEIN 84-47, "Environmental Qualification Tests of Electrical Terminal Blocks," was published to alert utilities of low insulation resistance of terminal blocks subjected to steam environment in low voltage or low current signal circuits.
o The CEMS sump level transmitters operate on a variable resistance principle, and would be less affected by reduced IR values of the cables and terminal blocks than a 4 to 20 mil 11 ampere transmitter.
Maine Yankee performed a review of terminal block inspection in response to IEIN 84-47 and removed all terminal blocks from EQ-related Rosemount transmitter circuits inside containment.
V.
ROOT CAUSE The root cause of not having identified these components was that o
Maine Yankee's initial walkdown was not conducted in accordance with a written walkdown procedure. A subsequent proceduralized O
walkdown discovered the components.
1-3 6745R/12.580
o The Maine Yankes EQ Program has 200 primary components and over 1,500 associated components (i.e., cables, splices, seals, etc.)
VI.
OTHER CONSIDERATIONS o
The deficiencies were limited to two containment sump level Weidmuller terminal blocks and four Continental cable runs, one of which included a States terminal block.
o Maine Yankee /YNSD personnel identified cables and terminal blocks during plant walkdown and EQ maintenance activities.
o Maine Yankee promptly identified the potential deficiencies to NRC through LER 87-005-00, dated June 25, 1987.
o Maine Yankee promptly implemented hardware changes to ensure full compliance.
o Regarding the Continental cable, Maine Yankee agrees that a deficiency existed but consistent with the licensee identification and prompt corrective action provision of GL 88-07, the deficiency should not be categorized greater than a Severity Level IV.
o Maine Yankee had completed its EQ Program development and documentation process prior to hovember 1985. The discovery of the deficiencies was a result of Maine Yankee's proactive approach to environmental qualification issues.
In an effort to improve the program, ensure continuous compliance and address industry concerns, Maine Yankee continuously reviews its EQ Program and has undertaken additional activities. One such activity was the proceduralized walkdown of EQ-related equipment. This demonstrates continued commitment to maintaining and enhancing the Maine Yankee EQ Program in light of evolving knowledge in the area.
O 1-4 6745R/12.580
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ITEM DESCRIPTION: Charging Pump Suction Vent Isolation Valves Qualification I.
AFFECTED EQUIPMENT / SYSTEMS o
SOV-4008A - Charging Pump Suction Line Vent Isolation Valve o
SOV-4008B - Charging Pump Suction Line Vent Isolation Valve o
SOV-4009A - Charging Pump Suction Line Vent Isolation Valve o
S0V-4009B - Charging Pump Suction Line Vent isolation Valve II.
IDENTIFICATION AND RESPONSE o
The valves were identified during a common power source and process flow review as part of Maine Yankee's ongoing EQ Program durf '.3 the period of March through May 1988.
o As a result of the review, four valves were identified which had the potential of being subjected to a harsh environment and were not included on the Maine Yankee EQ Master List, o
The NRC was notified per LER 88-005-00, dated June 22, 1988, and LER-88-005-01, dated August 10, 1988.
o Action was taken in June 1988 to fuse the solenoid circuits and implement procedural changes to require isolation of the manual ball valves.
o Modifications are being developed to replace the valves and to change their operational function.
III.
FULL EVALUATION / SAFETY SIGNIFICANCE o
Harsh environment (radiation dose level) potential was based on a worst case assumption and is not supported by a detailed calculation or analysis of the existing valve materials.
o The most severe valve failure mode, though highly unlikely, was assumed.
o In the event of a worst case solenoid failure (i.e., coil shorting), other devices sharing the same power supply would also have been de-energized.
o In the event of solenoid failure and valve opening, radioactive fluid would be prevented from releasing to the Primary Drain System by means of a pipe trap located downstream of the valves, o
Maine Yankee has concluded that no violation of 10 CFR 50.49 existed. A harsh environment did not nted to be assumed for these valves and, therefore, the valves were not required to be on the EQ Master List.
O 2-1 6746R/26.357
o Based on the planned design modification, regardless of whether a deficiency ever existed, the valves do not need to be included in O
the EQ Master List.
IV.
CLEARLY SHOULD HAVE KNOWN REVIEW o
The charging pump suction line vent isolation valves are located in EQ Zone PAB-1.
This area has the potential for a total integrated dose of 3.2x105 rads (i.e., 40-year normal dose plus DBE, one foot from recirculation line). The radiation sources are a hydrogen purge line and charcoal f11ter banks.
The source is located at a distance greater than 35 feet from the vent isolation valves (see Figure 1 attached).
o Based on this information, it is determined that the valves are not subjected to a radiation dose above 1x104 rada due to their proximity to the sources (see Figure 1 attached). Therefore, the valves are not required to be environmentally qualified or included in the EQ Master List.
o When the vent isolation valves were identified as part of the common power source review (which was performed in light of the Appendix R review), another analysis of potential radiation sources was performed.
The results of this analysis, based on conservative assumptions, determined that the vent isolation valves could be subjected to radiation dose above the threshold value of 1x104 rads.
Based on the results of this conservative approach, an LER was issued and modifications were initiated.
o Based on good engineering judgement, the opinion of Maine Yankee is that if a detailed analysis was performed to estimate actual dose levels and to determine valve materials, it could be shown that the existing valves would have remained operational. This judgement is based on the following:
1.
The preliminary analysis, which was the basis for reporting, assumed a radiation source term which included noble gases.
The gases dissolve in containment spray and be could omitted from a detailed analysis.
2.
The system geometry and shielding was simplistic and did not account for self-absorption, actual tubing dimension, valve enclosure, or tube wall shielding.
3.
A coarse energy group structure was used. Refinement of the low energy groups could reduce dose by accurately modeling the absorption.
4.
DBA dose from fluids in dead-ended piping was estimated to be ten times that of recirculating fluids.
5.
The dead-ended pipe, approximately 18 inches long, was assumed to be filled instantaneously upon start of recirculation.
O 2-2 6746R/26.357
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6.
The dose from hydrogen purge line was assumed to be 1 x 103 rad s.. A detailed review of distance and shielding would reduce this value.
V.
ROOT CAUSE o
The location of the valves in a harsh environment was not determined until the common power source and process flow reviews were performed.
o Fluid migration via the cross-tie is not easily quantifiable, and was not analyzed during the original review.
VI.
OTHER CONSIDERATIONS o
The deficiencies were limited to four valves on charging pump suction vent line having a comon power source with other components.
o Maine Yankee identified the valves during its review of EQ component power sources in May 1988.
o Maine Yankee made a determination that a potential problem existed in late May 1988 and conservatively reported it by LER 88-005-00 on June 22, 1988, with additional information submitted by LER-88-005-01 on August 10, 1988.
o Maine Yankee initiated hardware modifications (i.e., installed fuses) and procedure changes in June, 1988 upon determination of potential problems. Although Maine Yankee believes that this issue could have been resolved based on analysis as discussed above, it was determined that the hardware modifications represented a more prudent expenditure of resources to clearly resolve the issue.
o Maine Yankee had completed its EQ Program development and documentation process prior to November 1985. The discovery and notification of the potential deficiency was a result of Msine Yankee's proactive approach to environmental qualification issues.
In an effort to improve the program, ensure continuous compliance, and address new industry concerns, Maine Yankee has continuously i
reviewed its EQ Program and undertaken additional activities.
One j
such activity was the comon power source review which identified the charging line vent valves. This demonstrates continued l
comitment to maintaining and enhancing the EQ Program in light of I
evolving knowledge in the area.
O 2-3 6746R/26.357
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SUMMARY
- nb To summarize, Maine Yankee's position on the issues for this enforcement conference are as follows:
1.
Continental cable -- An EQ documentation deficiency existed. A qualification package did exist for outside use of Continental cable, but had been voided. The deficiency was licensee identified, promptly corrected, and of low safety significance.
2.
Weidmuller terminal blocks -- An EQ documentation deficiency existed for the terminal blocks, in that these components for the containment sump level transmitter circuit were not included on the EQ Master List. Ilowever, the terminal blocks were qualifiable in that documentation demonstrating qualification for inside containment use was on file at Maine Yankee.
Further, the failure to include theme terminal blocks in the EQ Master List was licensee identified, corrected, and of minimal safety significance (given that the
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components were qualifiable).
3.
States terminal block -- An EQ documentation deficiency existed for the terminal block, in that an inside containment analysis had not been performed and the component was not on the EQ Diagrams. The potencial temperatures induced RTD inaccuracy would have a minimal safety significance. Further, the failure to include the States terminal block on the EQ diagrams were identified by Maine Yankee, was prompely corrected, and had minimal safety significance.
I 4.
Charging Pump Suction Vent Isolation Valves -- This issue was conservatively identified and reported by Maine Yankee as a potential EQ deficiency in that it could be postulated that the valves would be in a harsh environment. Upon further evaluation, Maine Yankee believes that this is not an EQ deficiency because a harsh environment may not exist.
In any event, Maine Yankee clearly resolved any possible concern by conservatively deciding '.o luplement
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procedure and design modifications.
6748R/4.425
i, At all times the EQ Program has been adequately implemented and the plant
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safely operated.
Escalated enforcement action is not appropriate under the Modified Enforcement Policy for the above issues, either individually or collectively.
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6748R/4.425 i
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INTRODUCTION /0VERVIEW O
o TOPICS I.
INSPECTION AUDIT ITEM 50-309/87-16-13 (MAINE YANKEE IDENTIFIED)
CONTINENTAL CABLES FOR HOT AND COLD LEG RTDS AND STATES TERMINAL BLOCK FOR COLD LEG RTD (LER 87-005-00)
TERnINAL BLOCKS FOR CONTAINMENT SUMP LEVEL INSTRUMENT CIRCUITS (LER 87-005-00)
II.
LER 88-005-00 AND LER 88-005-01 (MAINE YANKEE IDENTIFIED)
SOLENOID VALVES ON HPSI/ CHARGING PUMP SUCTION VENT O
o NO ESCALATED ENr0RCEnENT ACTION IS WARRANTED UNDER TuE 80DIrIED ENFORCEMENT POLICY
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O
I PROGRAM STATUS c
SUMMARY
OF STATUS:
i CONTINENTAL CABLES AND STATES TERMINAL BLOCK REPLACED BY I
QUALIFIED CABLE i
WEIDMULLER TERMINAL BLOCKS REPLACED BY QUALIFIED RAYCHEM f
SPLICES i
DESIGN MODIFICATIONS ENSURE THAT SOVS DO NOT NEED TO BE ENVIRONMENTALLY QUALIFIFD i
o NO PROGRAMMATIC OR MANAGEMENT WEAKNESSES i
i o
MAINE YANKEE HAS TAKEN PROMPT MEASURES TO ENSURE THAT CONCERNS OR DEFICIENCIES ARE ADDRESSED O
o IN SOME CASES. MAINE rAuKEE HAS DECIDED TO 1MPLEMENr HARDWARE MODIFICATIONS RATHER THAN DEVOTE RESOURCES FOR ANALYSES i
o AT ALL TIMES PLANT WAS SAFE o
NO ENFORCEMENT IS APPROPRIATE l
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,s MAINE YANKEE IS COMMITTED TO IMPLEMENTING AND MAINTAINING A HIGH O
qual 1TT En PROGRAM SEVERAL ONGOING ACTIVITIES INCLUPE:
o AMBIENT TEMPERATURE MONITORING PROGRAM o
DEVELOPMENT OF MAINTENANCE PROCEDURES o
EQ TRAINING o
IMPROVEMENT OF DOCUMENTS o
RESPONDING TO NEW INDUSTRY CONCERNS INSPECTION AND ENFORCEMENT NOTICES AND BULLETINS LESSONS LEARNED FROM PREVIOUS ACTIVITIES INVOLVEMENT IN INDUSTRY GROUPS (I.E., NUGEQ, EPRI, IEEE)
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DATE CORRECTIVE HOV DATE TOPIC FOUND ACTION FOUND REPORTED Continental May 1987 Replaced Cables Valkdown 6-25-87 Cables (During (During Outage) and EQ (LER 87-005-00)
Outage)
Maintenance Activities Termino!
May 1987 Removed TB Valkdown 6-25-87 Blocks (Dur!ng Installed Splices (LER 87-005-00)
, Outage)
Replaced Cable (During Outage)
Solenoid 4 8 8 Added Fuses Connon 6-22-88 Vent Valves (Engineer-Revised EDPs Power 8 8 8 (LER 88-005-00)
Ing Review) (5-23-88)
Source (LER 88-005-01)
Review
ITEM:
CABLE AND TERMINAL BLOCK QUALIFICATION O
<50-309/87-16-13)
COMPONENTS INVOLVED:
7 CONTINENTAL CABLE - 4 CABLE RUN WEIDMULLER TERMINAL BLOCKS - 2 STATES TERMINAL BLOCK - 1 COMPONENTS AFFECTED 4 - RTDS (RCS HOT AND COLD LEG TEMPERATURE) 2 - LEVEL TRANSMITTERS (CONTAINMENT SIPtP LEVEL) i CHRONOLOGY o
ALL ISSUES WERE IDENTIFIED BY MAINE YANKEE DURING THE 1987 REFUELING OUTAGE (EQ VERIFICATION WALKDOWNS) o POTENTIAL ISSUES WERE PROMPTLY REPORTED IN LER 87-005-00, DATED MAY 25, 1987 1
o COMPONENTS WERE PROMPTLY REPLACED DURING THE 1987 REFUELING l
OUTAGE MAINE YANKEE POSITION o
WEIDMULLER TERMINAL BLOCKS WERE QUALIFIABLE, BUT WERE REPLACED AS A CONSERVATIVE ACTION o
CONTINENTAL CABLE AND STATES TERMINAL BLOCKS WERE PROMPTLY REPLACED DURING THE OUTAGE o
THE RTDS ARE REQUIRED TO FUNCTION IN A LESS SEVERED ACCIDENT 1
ENVIRONMENT O
o THE DEFICIENCIES UERE IDENTIFIED BY MAINE YANKEE, PROMPTLY CORRECTED, AND AT.E OF MINIMAL SAFCTY SIGNIFICANCE 1
ROOT CAUSE t/
o ORIGINAL WALKDOWN DID NOT UTILIZE A CONTROLLING PROCEDURE o
MAINE YANKEE HAS APPR0XIMATELY 200 MASTER LIST PRIMARY COMPONENTS AND OVER 1,500 SUPPORT ITEMS.
SEVEN SUPPORT ITEMS WERE MISSED DURING PREVIOUS WALKDOWN CORRECTIVE ACTIONS TO PREVENT RECURRENCE o
AS-BUILT DESIGN VERIFICATION WALKDOWNS ARE NOW REQUIRED BY PROCEDURE o
CONTINUED EQ TRAINING OF PLANT AND ENGI!EERING PERSONNEL o
CONTINUED REVIEW OF EQ-RELATED DOCUMENTS TO CLARIFY POTEFTIAL INTERPRETATIONS AND CONSIDER NEW TEST REPORTS O
o
^GGRESS1vE RESPONSE TO 1E N0 RICES AND BuLtET1NS o
ACTIVE INVOLVEMENT IN INDUSTRY GROUPS TO EXCHANGE EVOLVING KNOWLEDGE s
O
ITEM:
CHARGING PUMP SUCTION LINE VENT ISOLATION VALVES I
(LER 88-005-00)
(LER 88-005-01)
COMPO!ENTS 4 - SOLEN 0 IDS (CHARGING PUMP VENT ISOLATION VALVES)
CHRONOLOGY o
IDENTIFIED:
MAY 1988 (DURING COMMON POWER SOURCE REVIEW) o CONCERN:
A RADIATION ENVIRONMENT COULD BE POSTULATED IN THE VICINITY OF SOVs THAT HAVE NOT BEEN ENVIRONMENTALLY QUALIFIED o
REPORTED ON JUtG 22, 1988 AND AUGUST 10, 1988, BASED ON CONSERVATIVE ASSUMPTION h
o CORRECTIVE ACTIONS:
INSTALLED FUSES, JUNE 1988 MODIFIED OPERATION PROCEDURES, JUNE 1988 REPLACEMENT OF VALVES AND CIRCUIT MODIFICATION, ONGOING o
THESE ACTIONS ENSURE NO EQ CONCERN AND VALVE'i WILL NOT BE ADDED TO EQ MASTER LIST
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MAINE YANKEE POSITION O
o LOCATION OF VALVES WITH RESPECT TO RADIATION SOURCE o
INITIAL REVIEW DID NOT CONSIDER:
COMMON POWER SOURCE FLUID MIGRATION o
LER WAS PREPARED AND FILED REFLECTING A CONSERVATIVE APPROACH.
BASED IN PART ON A DECISION TO MAKE HARDWARE MODIFICATIONS o
DESIGN MODIFICATIONS RESOLVE ANY POSSIBLE CONCERN, REFLECTING COMPANY POLICY REGARDING ALLOCATION OF RESOURCES o
ENGINEERING JUDGMENT INDICATES THAT THE VALVES WOULD NOT SEE A HARSH ENVIRONMENT DUE TO FLUID MIGRATION O
o CROSSTIE IS ^ UNIouE CONrIGuRAT10N o
NO EQ VIOLATION OCCURRED 4
o THE DEFICIENCY WAS IDENTIFIED BY MAINE YANKEE, PROMPTLY l
CORRECTED, AND WAS OF MINIMAL SAFETY SIGNIFICANCE l
4 ROOT CAUSE o
INITIAL REVIEW DID NOT CONSIDER COMMON POWER SOURCE AND POTENTIAL FROM RADIATION MIGRATION IN THE VENT LINES t
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SUMMARY
o LIMITED NUMBER (I.E., 11) 0F COMPONENTS WITH QUALIFICATION CONCERNS o
BASED ON ENGINEERING JUDGMENT CABLES AND TERMINAL BLOCKS DEFICIENCIES HAD MINIMAL OR NO SAFETY SIGNIFICANCE
[
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VALVES ARE NOT ON THE EQ MASTER LIST.
THEY DID NOT INVOLVE AN I
EQ CONCERN AND ARE NOT REQUIRED TO BE ADDED TO THE EQ MASTER
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LIST.
BASED ON ENGINEERING JUDGMENT THIS DEFICIENCY HAS f
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MINIMAL OR NO SAFETY SIGNIFICANCE 4
i o
MAINE YANKEE SELF-IDENTIFIED THESE EQ CONCERNS AND RESOLVED 1
PROMPTLY WITH CONSERVATIVE ACTION i
o MAINE YANKEE HAS DEMONSTRATED BEST EFFORTS TO FULLY COMPLY WITH j
10CFR50.49 PRIOR TO THE NOVEMBER 30. 1985 DEADLINE i
i O
4 o
COLLECTIVELY OR INDIVIDUALLY, THESE ISSUES DO NOT WARRANT ESCALATED ENFORCEMENT ACTIONS l
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