ML20091A919
| ML20091A919 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/20/1992 |
| From: | Danni Smith PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9203300264 | |
| Download: ML20091A919 (11) | |
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10 CI'R 2.201 10 CPR 2.205
]
PHILADELPHIA ELECTRIC COMPANY t
NUCLEAR GROUP HEADQUARTERS j
955 65 CHESTERDROOK DLVD.
WAYNE.PA 19087 5691 j
o u. suim March 20, 1992 00meon vics f u ssicsN1. nucle An Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 Director, Of fice of Enforceraent U.
E. Nuclear Regulatory Commissior.
ATTN:
Document Control Desk i
Washington, DC 20555 SUBJLCT:
Peacn Bottom Atomic Power Station - Utilts 2 and 3 Reply to a Notice of Violation and Proposed Imposition of Civil Penalties NRC Inspection Report Nos. 50-277/91-33; 50-278/91-33 Attached is Philadelphia Electric Company's (PEco) response to the subject Notice of Violation (NOV).
The NOV was identified in the resident's routine inspection 91-33/33 and consisted of two parts.
Part A of the violation concerned a Technical Specification Violation due to Autor:,:. tic Depressurization Syntem (ADS) valves being inoperable on Uru t 3 and Part B concerned inadequate corrective action to ensure that a similar condition did not exist La Unit 2.
We feel that our comprehensive corrective actions identified in the attached response will preclude repetition of this violation.
Please find enclosed an affidavit and a check in payment of the civil penalty.
If you have any questions or desire further informai.lon, please do not hesitate to contact us.
Sincer'ly, M Ns cc T. T. Martin, Administrator, Region I, USNRC
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J. J. Lyash, USNRC Senior Resident Inspector hfY000
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PDR ADOCK 05000277 G
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. COMMONWEALll OF PENNSYLVANI A I
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COUNTY OF Cl! ESTER 1
D. M.
Smith, being first duly sworn, deposes and says:
That he is Senior Vice President-Nuclear, Philadelphia Electric Company; that ho has road the response to the Peach Bottom Atomic Power Station, Units 2 and 3 Notico of Violation and Proposed Imposition of Civil Penalties, and knows the contents thoroof; and that the statomonts and matters set forth thoroin are true and correct to the best of his knowledge, information and belief.
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Senior Vice President Subscribed and sworn to beforemethish ay Q-e of /2M44 2._,
1992.
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.Donument Control Desk Page,3 e
Hesponse to Notice of Violation 91-33-01 PART A 13estatement of the Violation Unit 3 Technical Spen;fication Limiting Condition for Operation (LCO) 3.5.E.1 requires that the Automatic Depressurization Subsystem be operable whenever there is irradiated fuel in the reactor vessel and the reactor l
pressure is greater than 105 psig and prior to a startup from a Cold Condition, except as specified in 3.5.E.2 below.
Unit 3 Technical Specification LCO 3.5.C.2 requires that from-I and after the date that one valve in the Autoinatic Depressurization Subsystem is made or found to be inoperable for any reason, continued reactor operation is permissible only during the succeeding seven days, unless such valve.ls sooner made operable, provided that during such seven days the HPCI subsystem is operable.
Unit 3 Technical Specification LCO 3.5.E.3 requires that if the requirements of 3.L.E cannot he met, an orderly shutdown shall be initiated and the reactor pressure shall be reduced to at least 105 psig within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Contrary to the above betreen December 7, 1989 (shortly after plant startup from a refueling outage) and September 14, 1991 (when the plant was shutdownLfor another refueling 4
outage), curing which-time the reactor was-operatino and reactor pressure was greater than 105-psig,-the Automatic Depressurization Subsy; tem (ADS) was Inoperable.
During that time, the HPCI subsystem was also inoperable for a total.of
- 510 hours0.0059 days <br />0.142 hours <br />8.43254e-4 weeks <br />1.94055e-4 months <br />., and the reactor wan not shutdown and reactor pressure was not reduced to at least-105 psig.- The ADS was inoperable due to incorrectly installed thermal insulation around the ADS safety relief valves, resulting-inLsignificant degradation of the associated solenoid operated valves, cables, and splices, and_in_the ability of the ADS valves to perform their intended safety function.
Admission or Denial of Alleged Violation PECo acknowledges the violation with the clarification-that l
two of the five ADS valves were determined by an engineering i
evaluation to be operable for design basis events.
TheLother three valves were outside of the environmental' qualification:
(EO) e.nvelope cond therefore may not have-functioned properly l-during certain design basis events. involving a-_ harsh environment in the drywell. -
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Background of the Violation During the pipe replacement outage in November 1987, the t
mirror insulation was removed from all 11 Unit 3 Main Steam Relief Valven (MSRV's) by the Peach Bottom Maintenance Pltter i
Croup.
The MSRV's were then removed and sent offsite for i
rebuild and testing.
After the MSRV's were serviced they were returned and reinstalled on September 5 and 6, 1989, by the Maintenance Pitter Group.
Extensive damage to the MSRV mirror insulation was identified by the fitters and they did not feel quallfled to perform the necessary repairs.
The reinculation of the MSRV's was then assigned to the contractor hired to reinstall drywell insulation.
Extensive repairs and alterations to the mirror insulation were performed by the contractor.
Following reinstallation of the j
insulation, several walkdowns of the mirror insulation in the drywell were conducted, but did not result in identification.
of the MSRV insulation deficiencies of the type identified during the eighth refueling outage.
i The Operataons Verification Form (OVP) for Maintenance Request Form (MRP) 8809258 for the pipe replacement modification stated that "all drywell insulation to be inspected on MRP 8803474".
However, no work was performed on
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MRP 88009474 and the OVP was signed off stating that fact._
i Three other MRPs were referenced for drywell insulation work, but none of their associated OVP's indicated that the inspection of the mirror insulation was conducted.
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Special Procedure 1142J was wrltten and approved by the Plant Operations Review Committee (PORC) to ensure that all
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insulation inside the drywell that was, or may have been, disturbed during the Unit 3 outage was properly repalted or replaced.
This procedure was very detailed and referenced the proper prints including the MSRV insulation detail. The special procedure was completed and closed out on November 16, 1989, but did not note any MSRV-insulation discrepancies.
A general drywell inspection was conducted-on December 1, 1989, but the MSRV insulation discrepancy'was not detected.
The Unit 3 generator was then synchronized to the-grid on December 11, 1989, with'the insula? ion installed in a manner with the body of the MSRV on the air operator end of the_-
i valve-uninsulated.
This resulted in temperatures-in_ excess of 400 degrees P around-the solenoid valve and associated i
cabling.
On October 27, 1990, Unit 3 was shutdown for a midcycle-outage.
During this time, the main valve seat of the "E" MSRV was cuspected to be leaking and was replaced by the-Maintenance Pitter Group.
A maintenance fitter craftsman questioned the orientation of the mirror insulation on the L,-,.._,..._m.,...-.,,.....-,~...-.,_..m.-.-----,,..
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MSRV.
To reinstall the insulation as he remembered, the insulation would require alteration.
The maintenance fitter craftsman also identified that all 11 MSRV's were installed l
in a similar manner.
This concern was expressed
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maintenance unit coordinater.
The maintenance unit coordinator knew that the MSRV insulation was extensively repaired during the pipe replacement outage and, based on the i
information presented to him, considered the MSRV's to be adequately insulated.
No follow-up investigation or evaluation was initiated, and Unit 3 was returned to service i
on November 21, 1990.
On Septembe-
'4,-1991, Unit 3 was shutdown for-the eighth refueling out. age.
During the performance of preventive maintenance tasks on September 24, 1991, it was discovered-that the associated wiring on three of the MSRV solenoid valves showed signs of heat damage.
This observation could not have been made during any of the previous walkdowns or -
inspections because-the damaged wiring was concealed in conduit.
After further exsmination, it was determined that heat damage on the MSRV's was the result of the improperly installed mirror insulation.
Reason for the violation A causal factor analysis has been performed concerning this event.
The most significant contributing factor of this event was that no one perceived any technical risk with insulation.
It was determined that the personnel involved in this event were primarily concerned about insulating piping and components.
They believed that the function of insulation was limited to thermal efficiency or' personnel protection.
It was only af ter t he event that the sianificance of insulating to protect critical equipment !? rom exposure to high temperature heat sources and-thermal degradation was fully realized.
Additionally, due to this perception, informatlon was never requested or provided on areae where insulation could be critica1'to currounding-equipment or components.
1 7nadequate training and guidance and inattention to detail were other factors in this violation.
Maintenance Request Form 8809258 did not contain sufficient MSHV insulation inspection details.
The inspection of drywell insulction after the pipe replacement falled to identify the discrepancies with the installed MSRV insulation.
-The.
performer of Special Procedure'SP: 1142J had seen the damaged MSRV insulation prior to its' repair and, when performing the final inepection, was so impressed by the improved visual and physical condition of the'MSRV' insulation that he did not identify the installation discrepancies.
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Document Control Desk Page 6 j
I There was also an occurrance where the lack of a questioning attitude by thn technical staff failed to identify the improperly installed insulation.
This opportunity occurred October 27, 1990, when a maintenance fitter craftsman questioned the orientation of the MSRV insulation.
This information was given to the maintenance unit coordinator who decided, based on his knowledge of the reinstallation, that the MSRVtu were properly installed.
No action was taken to investigate the potential problem.
i Assessment of Safety Significance PECo would like to comment on a statement made in the February 21, 1992, letter transmitting the Notice of Violation and Proposed Imposition of Civil Penalties.
The-statement in the last paragraph of page 2 of the letter reads, "Aa a result, the ability of-the plant to automatically cope with a small_to intermediate break LOCA was lost."
PEco disagrees with-this conclusion.
As presented at the Enforcement Conference on January 17, 1992, the intermediate bret< Loss of Coolant Accident-(LOCA) was determined to be the limiting event-for the circumstances dSaoClated with this violation.
Our analysis of this limiting event concluded that safe shutdown was achievable.
This analysis assumed:
- 1) an intermediate break LOCA, 2)
High Pressure Coolant Injection (HPCI) unavailable, 3) loss of offsite power, and 4) only two ADS valves available.
The assumption that only two ADS valves were available is considered to be conservative.
This assumption takes no credit for the one ADS valve whose solenoid valve van t.navailable for testing because it and been diccarded.
Purther, this assumption takes no credit for the two ADS valves whose solenoid valves passed the as-found " click" test, passed the as-found functional test and passed the vibration test, but required multiple attempts to pass either the LOCA or the non-LOCA test.
Additional informar!?n which supports the conclusion that safe shutdown was achievable is found in General Electric (GE) Report NEDC 30936P-A, "BWR Owners Group Technical Specification Improvement Methodology (With Demonstration for BWR ECCS Actuation Instrumentation) Part 1" dated December, 1988.
This report has been previously docketed with the NRC.
Table 3-7 of this. report states that two ADS valves are sufficient to depressurize the reactor for all small and-intermediate break LOCAs.- The sensitivity study associated with this table ensures that that peak clad temperature does not exceed 2200. degrees P.
PEco has confirmed-the applicability of this GE Report to PBAPS.
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Document Control Desk Page 7 Corrective Actions Taken and Results Achieved The Unit 3 MSRV's were removed and replaced during the eighth refueling cutage.
The Unit 3 Technical Specification Limiting Conditions for Operation (LCO) for ADS were exited when the plant was placed in shutdown with reactor pressure less than 105 psig.
Heplacement of these valves returned operability to ADS wriich would be required for plant start-up.
Administrative Procedure A-26, " Plant Work Process," was revised to prevent insulation tasks on certain safety-related components from being performed on blanket work orders.
A-26 now requires that insulation tasks on components such as MSPV's, Main Steam 1 solation Valves (MSIV's), ilPCI and-Reactor Core Isolation Cooling (9CIC) Turbine must receive Control Room approval for the release and return of equipment to service.
Insulation inspections were performed by the system engineers on high temperature safety-related systems.
These inspections did not identify any problems that adversely affected system operability.
This event was reviewed with the plant staff during a January 21, 1992, supervisory meeting.
Emphasis was-placed on the importance of insulation from an operability standpoint and the various functions that insulation provides to a component, system, and its surroundings.
Attention to detail and the pitfalls of poor detection practices when conducting acceptance of close-out inspections were also stressed.
A letter from the plant manager concerning the purpose of insulation and the controls to maintain its integrity was n
dist ributed to the plant staf f on January 24, 1992.
Corrective Steps that will be Taken to Avoid Further Violations As a follow-up to discussions with maintenance plannerr and foremen, the Maintenance Planner-Training Course will De revised to include guidance on insulation.
Addi*lonally, the course will be enhanced to emphasize the importance of providing appropriate references and specifications to ensure complete work packages.
T."is will be completed by March 31,-
1992.
This event will be formally discussed with maintenance planners and foremen.
The importance of providing necessary information and references to ensure work is completed properly will be stressed. -This will be completed by March 31, 1992.
This event will also be included in the next Technical Staff and Manager Continuing Training Course to be completed by April 15, 1992.
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Document Control Desk Page 8 i
Critical areas with i.nsulation design requirements will be identified and inspected.
Insulation design requirements for j
components, systems and environmental effects will be r
reviewed to ensure proper application.
Subtle design concerns involving insulation that could potentially cause operability concerns on-safety equipment will alta be evaluated.
Information concerning design requirements will also be l
captured in the Plant Intormation Management System for use i
by maintenance planners.
This will ensure that insulation tasks are not lost and will enhance the capability to provide complete work package information.
This event will also.be reviewt and discussed with personnel 4
who supervise contractors.
The importance of fully evaluating work scope and providing adequate information to perform that work will be stressed. - Additionally, the role of supervisors to ensure that work is performed correctly will be emphasized.
This will be accomplished by March 31, 1992.
t Date When Full Compliance Was Achieved Compliance with Technical Specifications was achieved on l
September 15, 1991, with the shutdown of Unit 3 and-reactor pressure less than 105 psig.
Insulation repairn were completed during the refueling outage and Unit 3-was returned to service on January 8, 1992.
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. Document Control Desk Page 9 Response to Notice of Violation 91-33-01 PART D Restatement of the Violation 10 CPR Part 60, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality and nonconformances are 9,omptly identified and corrected.
In the case of significant conditions adverse to quality, the cause of the condition shall bu determined and documented, and corrective action shall be documented and taken to preclude repetition.
Contrary to the above, although a significant condition aaverse to qualit/ was identified in September 1991 involving the degradation o. all five of the Unit 3 ADS valves because of improper insulation, adequate corrective actions were not taken to assure that a similar significant condition adverse to quality did not also exist on Unit 2 and to. correct such condition if it existed.
Specifically, although the licensee performed a visual inspection of the Unit 2 SRV's on October 17, 1991 to verify correct insulation, this inspection was inadequate in that it did not identify that insulation for the 'C" SRV (an ADS valve) was improperly installed.
As a result, the unit was returned to power operations without correcting this condition adverse to quality..
Admission or Denial of Alleged Violation 4
PECo acknow.adges the violation.
Background of t.he Violation On October 18, 1991, a maintenance engineer aware of the Unit 3 MSRV insulation problem inspected the Unit 2 MSRV's to collect nameplate data for the solenoid valves.
While collecting data on the Unit 2 MSRV's, the engineer also observed the installed insulation.
Aft.er the-inspection, he reported the results to his supervisor.
A pre planned inspection for the Unit 2 MSRV insulatlan was then cancelled based on the results of-the inspection of solenoid valves and insulation.
The-inspection failed to identify 1the
'2C' MSRV insulation discrepancy.
On October 19, 1991, an outage planning supervisor performed
.a work status walkdown in the area of the MSRV's.
He noticed the '2C' MSRV insulation discrepancy, but considered it to be adequately. insulated.
He mistakenly believed that convective heat transfer caused the damage to the Unit 3 MSRV's when in fact it was rudlant heat transfer.
Because of the nature of
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the insulation discrepancy on the
'2C' MSRV, he felt that the
'2C' MSRV would not be subject to convective heat transfer and, therefore, was not affected by the insulation discrepancy.
On February 3, 1992, an engineering evaluation cont ~irmed that the '20' MSRV was operable in this condition.
Reason for the Violation A causal factor analysis has been performed concerning this event.
The cause of the failure to identify the
'2C' MSRV insulation discrepancy was due to a cancellation of a pre-planned inspection on Unit 2 insulation for potential similar deficiencies as Unit 3.
The basis for cancellation was due to a walkdown concerning solenoid valves on October 18, 1991 by a maintenance engineer.
His walkdown included the solenoids on the 11 Unit 2 MSRV's.
Because he was familiar with the Unit 3 MSRV insulation discrepancy issue, he also observed the insulation condition during the-walkdown.
The maintenance engineer did not have the MSRV insulation detail print in-hand, but he understood the standard for insulating the MSRV.
Because the walkdown was not specifically for insulation, his attention to detail concerning insulation was diminished after finding the first five-of 11 MSRV's without discrepancies.
Contributing to this was a mindset that the discrepancy on the Unit 3 MSRV's was generic in nature in that insulation for all 11 MSRV's had been improperly installed.
The '2C' MSRV insulttion discrepuncy was unique for Unit 2.
The other ten MSRV's on Unit 2 were adequately insulated.
After the maintenance engineer reported his inspection results to nis supervisor, the supervisor was satisfied that the maintenance engineer understood the standard for MSRV insulation and had performed an adequate inspection.
The supervisor then cancelled the pre-planned i.nspection.
The cause of the failure to identify the impact c* the
'2C' MSRV insulation discrepancy during the outage plunning supervisor walkdown on October 19, 1991,-was due to his limited knowledge of the_ concern surrounding the Unit 3 MSRV insulation installation.
Had he known the effect of the insulation discrepancy concerning radiant vice convective f
heat transfer, he would have properly pursued remedial corrective actions.
Corrective Steps Taken and Results Achieved Thic event has been reviewed'wish plant staff personnel.at a plant supervisory meeting-on January 21, 1992.
Attention to detail, importance of pre-job planning,.and responsibilities-to thoroughly investigate and follow-up on-abnormal conditions were specifically addressed.
This discussion also
Document Control Desk Page 11 included the need to consider detail, significance, and complexity of each individual task before combining them.
This event has also been extensively d'.= cussed with personnel involved with this ev?nt as well as other appropriate plant groups.
Corrective Stegs that will be Taken to Avoid rurther Violationu Discussions held at the January 21, 1992, plant supervisors' meeting, with individualn involved and appropriate plant groups have been completed.
Appropriate plant staff are now aware of the importance of insulation as well as the importance of pre-planning and attention to detail.
PEco is also dedicated to the longer term enhancement of our process for review and disposition of conditions adverse to qua'lity.
Since mid-1991 we-have-assigned a Benior Er.gineer to our in-house events program as well as providing him with a competent-staff.
-Efforts have also been taken to strengthen applicable procedures and training, strengthen tho analysis of outstanding corrective action Atoms, track outstoding event reports and evaluate interim corrective
- or effectiveness.
I*. is felt that those actions are e'
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h antly enhancing our abilities to promptly identify e
m vect conditionc adverse to quality.
Plant staff has a, a ac
.>o J this concept and is providing good overall support for t.4e program.
Even though the number of identified events remained high, the number of reportable events and attention to detail events have shown a marked decrease since October, 1991.
Date When Pull Compliance Was Achieved Full compliance was achieved on December 15, 1991, O th the repair of the '2C' MSRV insulation discrepancies.
On February 3, 1992, an engineering evaluation concluded that insulation discrepancies in the '2C' MSRV at no time resulted in valve inoperability.
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