ML20137B342
| ML20137B342 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 03/14/1997 |
| From: | Subalusky W COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9703210283 | |
| Download: ML20137B342 (23) | |
Text
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- Gnnmonwealth I diwn1 Gimpan)
I.asalle &ncrating Station ;
S *~$ .
2 Nil North llM Road ,
Marvilles,11. 613 t la757
, TelMI5d5'4'6i March 14,1997 ,
United States Nuclear Regulatory Commission ,
Attention: Document Control Desk
- l Washingtcn, D.C. 20555
Subject:
RESPONSE TO APPARENT VIOLATIONS; NRC INSPECTION REPORTS 50-373/374-96013; AND 50-373/374-96018 ;
References:
J. L. Caldwell letter to W. T. Subalusky, dated January 1.
29,1997, Transmitting NRC Inspection ,
Report 373/374-96013 l
- 2. M. N. Leach letter to W. T. Subalusky, dated -
February 13,1997, Transmitting NRC Inspection ;
Report 373/374-96018 ;
i The enclosed attachments contain LaSalle County Station's response to the subject Apparent Violations that were transmitted in the Reference letters. i Attachment i responds to the issues associated with the corrective action program cited in both Reference 1 and 2. Attachment 2 responds to the issues associated with both the Auxiliary Electric Equipment Room and Control Room ventilation systems. ,
if there are any questions or comments conceming this letter, please refer them to me at (815) 357-6761, extension 3600.
Respectfully, W. T. Subalusky Site Vice President i l LaSalle County Station 9703210283 970314
! Enclosure PDR ADOCK 05000373.-
G PDR _
I cc: A. B. Beach, NRC Region ill Administrator M. P. Huber, NRC Senior Resident inspector - LaSalle
!/k' D. M. Skay, Project Manager - NRR - LaSalle 210064 M,@hN.U m i _ o , ,ae,
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ATTACHMENT 1
- LASALLE COUNTY STATION
- RESPONSE TO APPARENT VIOLATIONS l'
- ASSOCIATED WITH CORRECTIVE ACTIONS PROGRAM i
, INSPECTION REPORT 373/96013 e
INSPECTION REPORT 373/374-96018 4
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. DISCUSSION The NRC cited four events which demonstrate a failure to identify and/or correct significant conditions adverse to quality. We have reviewed each of the examples and other )
information relative to the state of the corrective action program at LaSalle County and the !
Comed Nuclear Operations Division (NOD). l The four events are particularly troubling to LaSalle County Station management because of the potential common mode failure of multiple safety systems present in two of the events, the failure to address generic aspects in one event, and failure to adequately address industry operating experience in two of the events.
1 We conclude that the fundamental underlying causes of the identified inadequacies of the corrective action program are the failure of station management to understand the importance of implementing the necessary corrective actions and to ensure accountability at all levels of the LaSalle organization to complete the corrective actions in a timely
. manner.
The program inadequacies are demonstrated by the failure to identify and correct the 1
important causes of the cited examples which include:
. Inadequate technical justification for deferral of identified corrective actions in the case of not resolving the problem with accumulation of water in the RCIC exhaust line leading to rupture disk failure.
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. Closure of a tracked item without the specified corrective action being completed in the case of recurrence of the breaker misalignment problem which impaired the breaker j capability during a seismic event. 1
. An ineffective program for the review of operating experience and vendor information j and the generallack of a questioning attitude on the part of plant personnelin the cases of the accumulation of foreign materialin the Unit 2 suppression pool caused by inadequate foreign material exclusion and inspection requirements, and the failure to replace degraded SBM control switches originally identified by the vendor in 1976.
To ensure a thorough understanding of performance issues at the LaSalle County Station, Comed commissioned an Independent Self Assessment Team. In December 1996, an intensive, independent self-assessment was performed by teams of experienced consultants and industry peers who reviewed the functional areas of Operations, Maintenance, Engineering, and Plant Support against the standard of best-performing plants in the industry. In the area of management and organization, it was identified that corrective actions have at times been slow, narrowly focused, deferred or incorrectly prioritized to resolve important issues. This was a validation of previous Comed and other assessments.
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We have taken aggressive action to change the leadership and enforce expectations of procedure adherence, questioning attitude, resolution of issues based on assumptions, and accountability within the organization. We are making significant changes to the corrective action program within the NOD. On the following pages, we provide our response to each of the four cited examples. In summary, we first want to provide an overview of the key points of our review and the programmatic corrective actions that we have taken and will take to improve the effectiveness of our corrective actions program.
ACTIONS TAKEN Over the past several months several new, industry experienced personnel have been placed at LaSalle, including: Plant General Manager; Unit 1 Plant Manager; Site Engineering Manager; Outage Manager; Units 1 and 2 Maintenance Superintendents; Safety Assessment Manager; Corrective Action Manager; and Site Quality Verification Directcr. These individuals bring proven industry records to help us meet our immediate and long term challenges. These managers will provide the leadership necessary to implement an effective corrective action program at all ievels.
Through the management approaches taken by this new leadership, the staff at LaSalle County will become more accountable in the identification and resolution of issues at the plant. We are driving this at alllevels of the organization. At recent "all hands" meetings en February 21 and March 7,1997, management conveyed and reinforced thair enpectation for LaSalle's improvement and the necessary elements of sh individual's contiDution to this effort. These include strict procedural adherence, strong use of the self-checking program, a questioning attitude and a demand for resolution of issues.
ACTIONS TO BE TAKEN i As stated above, the most important part of improving our corrective action program is the new leadership. We are also making substantive improvements in tr,e process through which our corrective action program is administered, as discussed in the following. '
The need to significantly improve the Corrective Action Programs at all Comed sites was identified as a result of the Comparative Assessment conducted by the Nuclear Oversight Department during the first half of 1996 and confirmed in assessments by INPO, NRC, and Site Quality Verification. This resulted in the creation of a Comed Corrective Actions Peer Group, with representatives from all six nuclear sites and the corporate office, that has been working since July 1996.
Beginning in the fall of 1996, a set of targeted improvement initiatives were undertaken at LaSalle County to reverse the performance trend. The 1996 Operational Plan provided for interim process changes to expedite improvement in the effectiveness of the corrective action program. These interim measures were not sufficiently aggressive and we recognize that significant improvements are necessary in root cause determinations and corrective action effectiveness reviewr to achieve the desired results.
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t j During the second half of 1996, the Comed Corrective Actions Peer Group developed a j i new corrective action program that is being implemented throughout the Comed NOD.
- The group reviewed state-of-the-art corrective action programs in the industry to establish s
a new corrective action process for the entire Comed nuclear program. The new process
- includes several improvements over the current program. It clearly delineates and ;
- standardizes the threshold for problem identification through Problem Identification Form .
. (Pl?) initiation, and establishes a common PIF database that provides greater ability to j i analyze PlF data. ;
i I i' The new corrective action process will encompass human error reduction methodology, including standardized coding, problem identification, trend analysis, and root cause
[ analysis techniques. To implement this process, Comed is identifying groups of dedicated I
{ root cause analysts and experts, specifically trained in root cause analysis techniques.
- Personnel will also be trained on the new corrective action process and on human error i
reduction techniques.
l To prevent recurrent events within the NOD, the procedures necessary to document j identified problems, properly screen them for significance and causal codes, and perform
- common cause analysis have been developed and approved. These procedures and the
} attendant computer software were implemented at Byron Station on March 3,1997, as a ,
! pilot effort. LaSalle County Station has developed a schedule to complete implementation i j of the new program by May 12,1997.
l l At LaSalle County, a new Corrective Action Manager position has been added to the
! organ lzation and filled with a senior, industry experienced individual. This manager is ,
! accountable for implementation and effectiveness of the new corrective action program. ,
j To facilitate this effort, a new Corrective Action Department has been created and i additional personnel are being added to increase root cause capabilities, in addition, we i j- recognized the need to enhance the availability and use of operating experience (OPEX) information. The operating experience function has been relocated to the new Corrective 4 Action Department and an OPEX Coordinator named. The Corrective Action Program ;
Manager will also be responsible for effective implementation of our OPEX process including an extensive effort to review past industry operating experience issues to determine which ones need to be re-addressed.
LaSalle County will no longer allow closure of NTS actions without proof that the action has been fully implemented. Management will take action as necessary to address cases where poor accountability is being demonstrated.
A NOD-wide common cause assessment will be completed by the end of June,1997, of the initial PlFs written under the new program. This first analysis will be based upon limited data but we believe that valuable insight will be gained by performing this early evaluation.
The frequency of the perfomiance of common cause analyses are now scheduled on a quarterly basis.
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i i Performance indicators, common to each Comed site, have also been developed to ,
i monitor the timeliness of implementation, quality of the corrective actions, and the number ;
i of significant events which are repeated. Site and Corporate management will take ,
appropriate actions based upon performance and results.
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t VIOLATION: 373/374-96013-08 The licensee's failure to implement corrective actions to address the accumulation of water in the RCIC exhaust line drain pot following the 1994 rupture disc event, was a contributing cause for the August 1996 event. The modification involving the installation of drain line taps was completed on Unit 2 during the February 1995 refueling outage. The modification was scheduled to be installed in the Unit 1 RCIC system during the January 1996 refueling outage, however, the modification was not initiated. The RCIC system engineer did not know why this modification had been deferred. The recommendation from the SQV audit 4
to implement a procedure for monitoring water accumulation before RCIC pump runs was also never acted on. If the licencee had implemented these recommendations, the
- accumulation of water in the drain pot may have been identified and consequently the August 1996 rupture disc event prevented.
The failure to ttke appropriate corrective action to preclude recurrence of a rupture disc event is considered an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI (50-373/96013-08).
. REASON FOR VIOLATION: 373/374-96013-08 Comed agrees that improvements to the Unit 1 RCIC drain pot piping have not been completed and that a procedural check for the presence of water in the drain line has not
- been implemented that would have prevented recurrence of the rupture disk event. A RCIC System improvement plan was prepared which identified the changes needed to prevent recurrence of the event. However, the plan was not fully implemented. The
, needed changes were completed on Unit 2. Similar changes to Unit 1 were scheduled to be completed during the January 1996 refueling outage but were deferred by senior management at LaSalle. At the time of the August 1996, Unit 1 RCIC event, these changes had not been completed.
A method was developed to determine whether water was present in the exhaust drain pot.
1 This method involved a physical verification of water in the flushing connection. However, this method was not proceduralized because it was thought that the physical modification would preclude the need for the procedural check.
CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED:
The modification to the Unit 1 drain pot piping to prevent recurrence of the rupture disk event will be installed prior to Unit 1 restart.
CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATION:
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The improvements described in the overview to these individual responses will be central to prevent further violations.
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Additionally, as described in the Restart Plan for Unit 1/ Unit 2, backlog items (e.g., ERs, PIFs/ root cause determinations / corrective actions, operator workarounds, control room deficiencies, outstanding ARs, and Work Requests) are being reviewed to determine ,
outstanding corrective actions which need to be completed prior to restart of the units.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance will be achieved prior to restart of the units. !
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1 VIOLATION: 373/374-96018-03a ;
The licensee's corrective actions to prevent recurrence of the 1995 breaker misalignment problem with the EDGCW pump breaker were not adequate or timely. As a result, similar ,
problems occurred with the MCC 136X-1 and 136X-2 supply breakers. The condition of the MCC supply breakers was safety significant in that the breakers may have opened during a seismic event interrupting normal and emergency power to those safety-related i loads supplied by the respective MCCs. The breaker alignment problems also represented l a potential common-mode failure that could have simultaneously affected multiple l safety-related systems. The failure to implement adequate and timely corrective actions 1 for the April 1995 common EDGCW pump breaker failure is considered an example of an I apparent violation of 10 CFR 50, Appendix B, Criterion XVI (50-373/96018-03a; 50-374/96018-03a).
l REASON FOR VIOLATION: 373/374-96018-03a )
l Comed acknowledges that the October 30,1996, breaker misalignment event resulted l from untimely and inadequate implementation of an identified corrective action from a previous event. In 1995, an identified corrective action to revise an Electrical Maintenance procedure, to check that the mechanical trip interlock of 480V switchgear breakers >
l disengages, was not implemented until February 1996. The procedure update occurred i after the subject MCC feeder breakers were retumed to service following refurbishment.
The tardiness of the procedure update was exacerbated by premature closure of the l Nuclear Tracking System item that tracked the procedure update. The item was incorrectly closed when the procedure revision was initiated but not completed. Additionally, the identified corrective action was inadequate since it did not address revision of Operations procedures and lacked adequate assessment of extent of condition. Operations personnel routinely rack breakers in/out without the presence of Electrical Maintenance. Electrical l
Maintenance is typically present for post maintenance breaker testing.
CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED:
- 2. Operations procedure LOP-AP-20 was revised and issued for use by December 31, ,
1996. It was revised to include verification that the mechanical trip interlock is '
disengaged prior to returning a breaker to service. The Just in Time training
- described in the following corrective step address _ed the interim period between identification of the problem and the procedure update. l l
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- 3. An aggressive effort has been underway to provide relevant and timely training to !
equipment operators. The first addressed short term needs and the remaining two address longer term operator training needs, e, immediate, "Just in Time", training was provided to all equipment operators on the mechanical trip interlock concem. This was a stopgap measure taken ,
to bridge the time period prior to the Operations procedure update. Included j in this training were inspection technique 3 to verify proper breaker to cubicle placement. This training was completed for the majority of equipment operators in the month of November,1996. The remaining operators who l
were off-site (i.e., vacation, license training) completed their training by early December 1996. -)
- b. As part of the non-licensed continuing training module (NLOCT Module-97-1) )
for equipment operators, a detailed handout and open forum discussion was l held with equipment operators. Proper racking and inspection techniques of !
480V switchgear breakers formed the core of this training module. This !
training was completed in January 1997.
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- 4. The 480V safety switchgear were inspected. Similar problems were not identified.
- 5. The 480V non-safety switchgear were inspected. Eight breakers were found with ):
this problem. Six of these had been previously identified and are awaiting -
scheduled bus outages for repair. Work packages have been initiated for the !
remainin'g two breakers that were not previously identified.
CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATION: l l
The improvements described in the overview to these individual responses will be central to prevent further violations. The following actions specific to this problem are being taken.
- 1. Training of new equipment operators will be handled in the Initial High Voltage i Switching training module. A lesson plan will be developed that includes the lessons leamed from this event. Training urMg this new lesson plan will be accomplished prior to startup of either unit,
- 2. As part of the restart effort at LaSalle County Station, an additional training module entitled High Intensity Training will be provided to equipment operators. A component of this training will address breaker and switchgoar concerns. System Engineering will participate in this effort. Training completion will occur prior to unit startup.
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i 3. All 480V non-safety switchgear breakers were inspected for this problem. A total of eight breakers were identified with this problem. Six of these had been previously identified and are awaiting scheduled bus outages for repair. Work packages have been initiated for the remaining two breakers that were not identified. Repairs for Unit 1 breakers will be completed prior to Unit 1 startup. Similarly, repairs for Unit 2 breakers will be completed prior to Unit 2 startup.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance will be achieved for all modes of operation prior to the restart of the units from their current outages L1F35 and L2R07.
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t VIOLATION: 373/374-96018-03b i
The accumulation of foreign material in the Unit 2 suppression pool was caused by the failure to implement an effective FME program during initial construction and the first few unit outages. The licensee did not identify the presence of foreign material earlier due to
- inadequate inspections. The licensee had strengthened FME controls before discovering the material in the sitt layer of the Unit 2 suppression poolin October 1996. The foreign material could have potentially caused a common-mode failure of the ECCS. The failure to l identify and correct this significant condition adverse to quality during previous inspections i i of the Unit 2 suppression pool, is considered an example of an apparent violation of I j 10 CFR 50, Appendix B, Criterion XVI (50-373/96018-03b; 50-374/96018-03b).
REASON FOR VIOLATION: 373/374-96018-03b This event resulted from past inadequacies in the Foreign Material Exclusion (FME)
Program in primary containment and inadequate previous pressure suppression pool (PSP) inspections and cleaning. In response to IEB 93-02, LaSalle did not identify and remove a considerable amount of foreign material during Suppression Pool cleanliness
! inspections performed during L2R03 and L2R06. The majority of this material was discovered under the accumulated floor silt layer during L2R07 desludging activities. l Previous inspections had not disturbed the silt layer nor included a thorough inspection of all downcomers because inspection instructions had focused on locating and removing detectable debris without disturbing the shallow silt layer. Instructions were not included to
- thoroughly inspect all downcomers which reflects a lack of questioning attitude to fully determine the scope of, and thoroughly resolve the problem.
CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED:
- e A thorough underwater foreign material inspection was conducted of the entire Unit 2 Suppression Pool and 100% of the Suppression Pool downcomers. The result of this inspection was satisfactory.
. A self assessment was peiformed of the current compliance of the site workforce to the i requirements of the Foreign Material Exclusion Program procedures. Weaknesses were identified, and immediate corrective actions were implemented. )
. A confirmatory inspection of 100% of the Unit 1 suppression pool downcomers was ;
performed in February,1997. The results of this inspection were satisfactory. The
- Unit 1 pressure suppression pool had previously been inspected and thoroughly cleaned in March,1996.
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CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATION:
The improvements described in the overview to these individual responses will be central to prevent further violations.
Additional steps specific to this issue that will be taken include:
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. issuance and training to revised Foreign Material Exclusion procedures to address the l issues identified during the self assessment.
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. design and fabrication of Drywell downcomer foreign material exclusion covers to be used for future outages.
. definition of a Suppression Pool desludging frequency consistent with the design of LaSalle's new ECCS suction strainers.
. installation of larger capacity passive ECCS suction strainers no later than the next scheduled refuel outage for each Unit (L1R08/L2R08) as part of LaSalle's response to NRC Bulletin 96-03.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance was achieved on October 16,1996, with the inspection and cleaning of the Unit 2 pressure suppression pool.
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1 VIOLATION: 373/374-96018-03c Degraded SBM switches due to hydrocarbon exposure and excessive age represented a potential common-mode failure which could simultaneously affect multiple safety-related systems. The failure to take appropriate corrective action for safaty-related SBM switch I degradation concems identified in 1979,1990, and 1995 is considered an example of an l l apparent violation of 10 CFR 50, Appendix B, Criterion XVI (50-373/96018-03c; 50-374/96018-03c).
l REASON FOR VIOLATION: 373/374-96018-03c Backaround j GE Service Advice Letter (SAL) 721-202.1, issued February 1976, identified that the CAM I
followers used in SBM switches manufactured from July 1972 through May 1975 were exposed to hydrocarbon contamination and as a result are subject to deterioration. No recommended actions were provided in this SAL.
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GE Service Information Letter (SIL) 155, dated March 1976, identified the same issue l reported in SAL 721-202.1. Additionally, GE recommended replacing all SBM switches !
with suspect date codes in use in class 1E applications. SIL 155 also recommended 4 inspecting all suspect date code SBM switches used in non-class 1E applications and ;
replacing them if appropriate (based on switch condition, application and frequency of use). ,
1 Four months later, supplement 1 to SIL 155 was issued. This supplement deleted all t previous recommendations made in the original SIL and made new recommendations.
These new recommendations stated that all SBM switches, regardless of application, j should be inspected. If, during the inspection, the cam followers were found to be severely-cracked the switch should then be replaced. Supplement 1 also recommended that l j
switches found to have minor cam follower cracks be evaluated for replacement based on application and frequency of use.
Supplement 2 to SIL 155 was issued in November 1979. The intent of supplement 2 was "to remind BWR operators of the need to inspect SBM switches according to the instructions of SIL 155, supplement 1." No new recommendations were made by supplement 2.
1979 GE Walkdown Following the recommendations in supplement 1 to Sll 155, LaSalle arranged for GE to perform an on site. inspection of installed SBM switches. This inspection began on December 5,1978 and was completed on March 26,1979. The inspection report indicates that all 536, of then installed, panels were inspected. Suspect switches were replaced as l
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4 part of the inspection. The report also states that there were 106 suspect date code
- . switches on 59 GE Nuclear Energy (GENE) panels not yet installed in the plant. ,
- Additionally, the report states that GENE "should be able to provide documentation that the !
i (106) switches are not defective." No record at LaSalle has been found to indicate that !
these 106 switches'were inspected or that any documentation was received from GENE !
- stating that the switches were not defective. This indicates an apparent failure to follow
- through on necessary corrective actions.
l Due to the length of time since the 1979 walkdown, it is not possible to determine the l reason the actions required to resolve this problem were not completed. However, based i
- on the results of the recently completed walkdowns and ongoing replacement activities, it ;
j appears no action was taken to thoroughly investigate the extent of the problem and take j q the required corrective actions. The visual indications of cam follower degradation that are !
i apparent today should have led to a decision to replace the switches in question. !
i Considering the characteristic of Lexan cam cracking due to the presence of hydrocarbons :
! and the highly stressed condition in the vicinity of the roll pins, it would be expected that !
l today's visual as-found condition should be the same as that in 1979. I i'
j Division ill Switchaear inspection l
! In February 1990, an inspection of the unit 1 division 111 switchgear was conducted by GE l 4
and LaSalle personnel to assess overall equipment condition and correct any deficiencies. l
! A similar inspection was performed on the unit 2 division lll switchgear in January 1992. ;
j- During these inspections, it was noted that several of the division lll switchgear SBM l switches had suspect date codes as identified by SIL 155. During the division lil ;
i' switchgear work the more conservative approach of replacing all division 111 suspect SBM :
! switches was taken. However, the discovery of the suspect date codes in the division ill :
4 switchgear did not result in an " extent of condition determination" being completed.
- In August of 1995 a review of the actions taken relative to SIL 155 was performed. The i
report associated with this review states that "it is reasonable to assume" that any switches i identified as having cracked cam followers were replaced. This indicates a lack of a l sufficiently questioning attitude to ensure a problem is thoroughly understood and resolved. l
! l j' CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED:
L LaSalle is replacing all safety-related SBM switches and SBM switches deemed to be important to reliable plant operations. A walkdown of panels has been performed to
- identify SBM switches, to inspect their condition and identify date codes. A review of all electrical drawings has been completed to ensure that all SBM switches were identified in i the walkdown. Replacement of these switches is currently in process for both Units 1 and
- 2 and will be' completed prior to restart from the current outages.
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,r CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATIONS:
I The improvements described in the overview to these individual rasponses will be central to prevent further violations.
Specific to this issue, GE operating experience information (i.e., SILs), will be reviewed as part of the LaSalle County Restart Action Plan to identify where other corrective actions are required prior to restart.
Future reviews of GE SILs will be accomplished through the recently approved procedure NSWP-A-06 Operating Experience (OPEX). This procedure requires the assignment of
. subject matter experts who are responsible for the quality and timeliness of generating experience information review.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance will be achieved prior to either unit restart following the replacement of SBM switches with suspect date codes or installed in safety related or equipment important to plant operations.
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l LASALLE COUNTY STATION RESPONSE TO APPARENT VIOLATIONS ASSOCIATED VENTILATION SYSTEMS INSPECTION REPORT 373/96013 INSPECTION REPORT 373/374-96018 l
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i j VIOLATION: 373/374-96018-04 i
! In October 1996 it was determined that the AEER ventilation system could not maintain the I AEER at a positive pressure of 1/8 inch water column (WC) as specified in Section 6.4 of i
, the UFSAR. If pressure in the AEER is less than 1/8 inch WC the post-accident dose to l personnel in the AEER would have exceeded the limits in General Design Criteria (GDC) ;
- 19. Technical Specification bases 3.7.2 states that the operability of the control room and l j AEER emergency filtration system is based on the radiation exposure limitations of 10CFR l i Part 50 Appendix A GDC 19. Consequently, the AEER ventilation system was inoperable J i since it was unable to perform its intended safety function. The failure to maintain the l
, AEER ventilation system operable since initial plant operation is considered an apparent !
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violation of TS 3.7.2 (50-373/96018-04; 50-374/96018-04).
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VIOLATICN: 373/374-96018-05 l 1
I 10 CFR 50, Appendix B, Criterion XI," Test Control" requires, in part; that a test program l l shall be established to assure that all testing required to demonstrate that structures, l systems, and components will perform satisfactorily in service is identified and performed i j in accordance with written test procedures which incorporate the requirements and
[ acceptance limits contained in applicable design documents; that the test results shall be
! documented and evaluated to assure that test requirements have been satisfied.
Contrary to the above:
- a. During the initial pre-operational testing of the Auxiliary Electric Equipment Room j (AEER) ventilation system (VE), when a differential pressure (DP) of 1/8" WC could
! not be maintained, the test acceptance criteria for DP was revised to 1/16" WC. In
!- June 1982, after conducting a second pre-operational test, the pressurization test
- result was accepted based on the revised acceptance criteria. The revision to the l test acceptance criteria was not evaluated to assure that the test results satisfy the
- - VE system's design and licensing basis.
i b. The post-modification testing performed after the Computer Room was separated
- from the AEER ventilation system, did not address the ability of the newly modified l VE system to maintain the required design DP of 1/8" WC.
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s REASON FOR VIOLATION: 373/374-96018-04 and 05alb
, Comed acknowledges that the AEER ventilation system has been inoperable and that both the pre-operational and post modification testing did not evaluate for a positive 1/8 inch
- . water column (wc). The reason for these apparent violations is that personnel involved believed that the AEER was not required to be habitable and failed to effectively follow-up to resolve the apparent conflict with the UFSAR and Technical Specifications. Our basis for concluding this is three fold.
- 1. The pre-operational testing did include the requirement for the 1/8 inch water column (wc) differential between the AEER and adjacent spaces. When this was :
not achieved during performance of the pre-op test, the discrepancy was reported 1 and although we found no documented technical justification for acceptance, the i results of the test were accepted, y
- 2. The NRC submitted FSAR question (No. 312.7), regarding the habitability of the AEER. Our response, contained in FSAR Amendment 22 dated May 1977, '
indicated that operator action would not be required from the AEER following a DBA.
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- 3. The modification which separated the ventilation to the computer room from the i AEER ventilation system identified the need to verify the 1/8" wc differential 1 pressure. This was to be verified as part of post modification VE system balancing. 1 The balancing was performed after installation of the modification which restricted ;
flow from the AEER to the computer room to 100 cfm. However, the requirement to I verify the 1/8" wc value had been removed in a revision to the modification. The l Post LOCA Habitability Study for CR and AEER completed in 1988 concluded that the habitability of the AEER was not required. A Technical Specification change i was submitted in 1990 to revise the charcoal filter testing program, and in addition, J to exclude the AEER from Technical Specification 3.7.2 as an area not requiring habitability. The Technical Specification change was later withdrawn by Comed due to difficulties in resolving questions with the charcoal filter testing program.
However, no actions were taken to reinstitute the AEER testing.
The Technical Specifications Bases Section 3/4.7.2 and UFSAR Section 6.4 currently indicate that the control room and AEER are habitable areas for operations personnel.
The modification to remove the MSIVLCS did not consider the effect of removal on AEER habitability. Specifically, the impact on AEER dose rates had not been considered before removalof the MSIVLCS.
The analysis for this modification did consider the effects of MSIVLCS removal on off-site and control room doses. The reason for not considering the impact on the AEER has not been established. The cause may be that individuals involved with the modification did not believe that the AEER was required to be habitable. A contributing factor may relate to the fact that FSAR Section 15 accident analysis does not specifically address dose rates for )
the AEER. i 2
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- The evaluation activities associated with preparing and installing this modification provided i
an opportunity to identify the design bases problem described above for the VE system.
However, the failure of the VE system to comply with the design bases was again not recognized.
CORRECTIVE ACTIONSTAKEN AND RESULTS ACHIEVED:
a A functional and design review of the AEER ventilation system (VE) has been completed.
- Actions required to return VE to full operability and compliance with the UFSAR and Technical Specifications will be completed prior to restart. This includes providing for !
habitability of the AEER, as it was recognized in October 1996, to provide access to a
', hydrogen recombiner control panel located in the room. l
- l A review is being performed of Technical Specification changes that have been initiated.
The review will verify that current actions for any issues that were not submitted, not approved by the NRC or were withdrawn by Comed are sufficient to demonstrate compliance with Technical Specification requirements. This review will be completed by August 31,1997. Corrective actions required for safe plant operation will be resolved prior to restart.
The effects of removal of MSIVLSC on AEER habitability have been evaluated. The i
evaluation has concluded that removal of MSIVLCS does not render the VE system !
inoperable. An independent design review of the modification that removed the MSIVLCS is being performed to determine if any other impacts were not considered. These reviews l will be completed by May 30,1997. Any resulting actions required for safe plant operation will be resolved prior to restart.
CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATIONS:
The corrective actions above will bound this condition and confirm that appropriate surveillance test procedures are in place and used.
A sample of modifications will be selected and reviewed to determine if appropriate design reviews were completed. These reviews will be completed by June 30,1997. Any resulting actions required for safe plant operation will be resolved prior to restart. The results of the review of these modifications will be used to determine if further review of other technical specifications will be performed.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance will be achieved upon declaring the VE system OPERABLE which is dependent upon effective implementation of the applicable engineering procedure.
Operability of the VE system is required prior to changing modes on either reactor.
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o VIOLATION: 373/374-96018-06 )
l LaSalle Technical Surveillance procedure LTS-400-17, " Control Room HVAC isolation Damper Surveillance Smoke and Radiation Detection," Revision 5, did not verify the capability of the control room (CR) ventilation system to maintain a positive pressure in the CR relative to g surrounding areas. The surveillance test only evaluated the pressure of the CR relative to the Auxiliary Building and Turbine Building areas adjacent to the CR.
The test did not evaluate the pressure of the CR relative to areas adjacent to the top and bottom of the CR and adjacent areas in the secondary containment. Technical Specification 4.7.2.d requires that each CR emergency filtration system train be demonstrated operable at least once per 18 months by verifying that the emergency train automatically switches to the pressurization mode of operation on an actuation signal and maintains the CR at a positive pressure of 1/8 inch water gauge relative to adjacent areas.
The failure to test the CR ventilation system since initial plant operation to ensure that the CR can be maintained at the specified positive pressure relative to g adjacent areas, is ,
considered an apparent violation of TS 4.7.2.d (50-373/96018-06; 50-374/96018-06). j REASON FOR VIOLATION: 373/374-96018-06 The reason for the failure to have appropriate surveillance test procedures from the time of initial operation is unknown.
CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED:
Surveillance testing requirements are being established and procedures developed to provide for testing the relative pressure differential between the CR and all adjacent areas.
These procedures will be completed and testing performed to verify that a positive pressure is maintained between the CR and adjacent areas prior to restart. l CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATION:
The extent of condition for this type of problem will be evaluated as part of the System Functional Review Program which has been initiated. The program is being conducted for systems important to safe and reliable operation and includes (1) determining the required system functions derived from the design bases, (2) identifying materiel condition problems that affect achieving these functions and (3) ensuring periodic testing requirements adequately confirm system functions. Corrective actions, including design changes and maintenance activities, will be implemented when required to ensure the system functions are achieved. If substantive functional' problems are encountered, a detailed design review will be performed to confirm whether supporting detailed analyses are available and identify necessary design changes.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance will be achieved prior to any mode changes. Unit 1 is currently in mode 4 and Unit 2 is defueled.
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ADDITIONAL EXAMPLE OF VIOLATION 373/374-96018-06 DISCUSSION:
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! An additional Technical Specification issue associated with the control room ventilation system was identified by LaSalle County. On December 17,1996, an independent review of selected Technical Specification (TS) Clarifications, identified an apparent inccr.sistency i between the TS Clarification related to the Main Control Room Atmospheric Control :
System (MCRACS) Radiation Monitoring System and TS 3.4.7.1. On January 13,1997, the subsequent investigation determined that (1) there was a functional inconsistency between the Design Basis as described in the FSAR text and the FSAR Logic Diagram for the MCRACS. The original installed design matched the logic diagram, (2) the modified .
design installed in 1993 was not consistent with either Design Basis as described in the FSAR text or as shown on the FSAR Logic Diagram and (3) SER Section 9.4.1 indicates that no single failure within the control circuit for the isolation dampers will result in a failed open Control Room Ventilation System.
The modified design installed in 1993 does not meet this Single Failure Criteria and was not consistent with SER 9.4.1 and consequently introduced an Unreviewed Safety Question. Subsequent engineering review has determined that a postulated single failure in the modified circuitry combined with a Design Basis Accident could have resulted in a failure of the Control Room Ventilation System Isolation dampers to isolate resulting in a radiation exposure to Control Room Personnel in excess of 10 CFR 50 Appendix A General Design Criteria 19 limits.
REASON FOR THE VIOLATION:
The safety evaluation for the modifications performed in 1993 was inadequate in that LaSalle County failed to recognize that damper isolation for the control room ventilation air intakes is not functionally redundant. Therefore, the modified design would have allowed a single failure to result in the failure to isolate one train.
Contributing to this event was a failure to conduct an adequate in-depth review of the documentation which comprise the licensing basis. The evaluation of the modification for conformance to single failure criteria, focused on single failure events described in the UFSAR and on the apparent functional redundancy of the two trains of ventilation. The safety evaluation determined that the change did not constitute an unreviewed safety question was based upon the text description in section 6.4.4 of the UFSAR. However, this ,
description was in conflict with other design basis documentation as well as in conflict with I the facility installed configuration. The root cause of this conflict is not known. The discrepancy existed at the time of licensing the facility. LaSalle County Station fciled to review key documents other than the UFSAR which would have identified thme ;
discrepancies. At the time the safety evaluation was performed, LaSalle County Safety l Evaluation Procedures focused on reviews of the UFSAR and the Technical Specifications i and did not specifically direct the reviewers to other license bases such as the FSAR and l the SER. Reviews at that time were mainly limited to hard copy searches with limited electronic search capabilities.
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In Updating the FSAR, numerous drawings had been removed for simplification of the l UFSAR. The system logic diagram in the FSAR which depicted a different design had i been incorrectly deleted from the UFSAR and review of the FSAR was not specifically l called out in the Safety Evaluation Procedures at LaSalle County Station at the time. !
CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED: i The Safety Evaluation for the modification was performed in September,1992. The ;
procedures and culture of the facility at that time was such that sufficient rigor was not always exercised in the Safety Evaluation process. Numerous programmatic weaknesses i were subsequently identified with LaSalle County's Safety Evaluation process. Corrective actions were taken which included increased training and programmatic changes resulting in more rigor and thoroughness in the Safety Evaluation and modification review and approval process. The Safety Evaluation Procedures were revised to specifically require reviews of the additional documentation which make up the license basis other than the UFSAR and Tech Specs. The documents comprising the license bases are now available for electronic searches which assist in a more thorough review and evaluation process CORRECTIVE ACTIONS TO BE TAKEN TO PREVENT FURTHER VIOLATIONS:
The extent of condition for this type problem will be evaluated as part oi the System Functional Performance Review Program. This program is being conducted for systems important to safe and reliable operation and includes (1) determining the required system functions derived from the design bases, (2) identifying materiel condition problems that affect achieving these functions and (3) ensuring the periodic testing requirements adequately confirm system functions. Corrective actions including design changes and maintenance activities will be implemented when required to ensure the system functions are achieved. If substantive functional problems are encountered, a detailed design review will be performed to confirm whether supporting detailed analyses are available and identify necessary design changes.
A modification will be developed to correct the installed design. The original ch&: nel separation and redundancy will be restored. The revised design will meet the single failure criterion of the design basis. This will be completed on each unit prior to restart. :
Prior to restart the Technical Specifications will be revised to conform to the design and to eliminate confusion in the wording of the action statement.
As described in Comed letter T. J. Maiman to A. B. Beach dated January 30,1997,
" Comed Plan for Upgrading the Quality and Access to Design Information at All Six Nuclear Stations," we are embarking on a comprehensive program to prepare a major scope of design basis documents. This program willinclude review of the FSAR, the UFSAR, applicable SERs and the Technical Specifications. This review will ensure conformance of the plant design with the design bases, and is expected to identify discrepancies such as the above.
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