ML17354A304
| ML17354A304 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point, Saint Lucie  |
| Issue date: | 10/22/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17354A300 | List: |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, NUDOCS 9610250179 | |
| Download: ML17354A304 (19) | |
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oi Cy Wy*y4 UNITED STATES NUCLEAR REGULATORY COMMISSlON WASHINGTON, D.C. 2055&4001 SU ENT L SAF Y EVALUATION BY THE OFFICE OF NUCLEA REACTOR REGULATION EVALUATION OF THE FLORIDA POMER AND LIGHT CONPANY'S
RESPONSE
TO GENERIC LETTER 87-02 ST.
LUCIE UNIT 1
AND TURKEY POINT UNITS 3 AND 4 DOCKET NOS. 50-335 50-250 251 1.0
~IM7 OUCTI N
By letter dated February 9, 1995, the staff issued a safety evaluation (SE) on the Florida Power and Light Company's (the licensee, FPL) implementation program for addressing Generic Letter 87-02, "Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating
- Reactors, Unresolved Safety Issue (USI) A-46."
In the SE, the staff identified several open items, and indicated that a site audit would be conducted to address the open items.
The audit was performed December 4 through &, 1995, by a team consisting of two members from NRR, one member from Region I, and one contractor from Brookhaven National Laboratory (BNL).
This supplemental safety evaluation provides the NRC staff results of the audit.
2.0 DISPOSITION OF SE OPEN ITENS The audit was conducted in part at the licensee's corporate offices and at the Turkey Point plant site.
During the visit to the corporate offices, the licensee presented an overview of its USI A-46 program, including details of its program for addressing concerns with electrical relays.
Discussions were also held with the licensee's Seismic Review Team (SRT), consisting of three expert seismic consultants from the nuclear industry, who performed the equipment walkdowns.
It is noted that the SRT members were extensively involved in -the development and review of the equipment experience database utilized in the USI A-46 generic resolution program.
During the site visit, the staff performed inspection walkdowns of several equipment items in the safe shutdown path.
Since the plant was in operation, extreme care was taken to avoid upsetting the equipment during the walkdowns.
Consequently, the walkdgyn portion of the audit was mostly limited to external visual observations.
T e audit findings relating to the previously-open SE items are discussed below.
~SE Ite 1
Staff's review of the methods used to develop the in-structure response
, spectra for performing equipment evaluations.
96l0250179 96i022 PDR ADCICK 05000250 P
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Audit Observations and Findin s The staff reviewed the in-structure response spectra (IRS) developed by the licensee during its audit meeting of December 4-8, 1995.
The staff observed that the licensee had developed the IRS for the Containment, Auxiliary and the Control'buildings.
No specific method for developing the IRS was identified.
However, the overall amplifications of the ground motion through the buildings appeared reasonable.
During discussions with the licensee's SRT members (consisting of Robert Kennedy, John Reed and John Stevenson),
the staff found that because of the relatively low heights of other seismic Category I structures, the SRT used judgments to estimate the amplified motion.
For
- example, the anchorage calculations were performed by using either the peak (irrespective of the frequency of the equipment) spectral accelerations of the available IRS, or 1.875 times the peak ground acceleration of the ground response spectrum.
The factor 1.875 is 1.5 times 1.25 used for anchorage evaluation of relatively rigid equipment (frequencies above 8Hz) under GIP-2 criteria when the equipment is located within 40 feet above the grade elevation.
Therefore, for the equipment located in the low structures at the plant, for which the IRS have not been developed, the staff found the SRT judgement acceptable.
For the resolution of USI A-46, the staff considers the mixed use of IRS and the SRT criterion acceptable, and this item is closed.
SE Item 2-Staff's verification, by sampling, that the Turkey Point safe shutdown equipment is similar to equipment in the experience database.
Audit Observations and Findin s The staff discussed this issue with the licensee and the SRT members.
As noted previously, the SRT members are recognized seismic experts who were closely involved, with the development and review of the equipment classes included in the experience database.
The SRT confirmed that the safe shutdown equipment at Turkey Point is representative of what they observed during their review of the database facilities.
In addition, the staff performed walkdown inspections of selected equipment items during the site audit, and found that the equipment items were procured from major nuclear equipment vendors, and were typical of those observed in any such large industrial facilities; including those in the experience database.
Based on this information, the staff concluded that the Turkey Point safe shutdown equipment is representative of that in the database, and therefore, the use of the experience database criteria to establish equipment seismic adequacy is appropriate.
This item is closed.
SE Item 3 Staff's review of selected safe shutdown equipment items and raceway systems which were excluded from the licensee's seismic verification walkdowns.
Audit Observations and Findin s E ui ment Items The staff reviewed information related to selected equipment items that are included in the safe shutdown path, but were not included in the licensee's
detailed walkdowns.
In addition, the staff inspected a sample of the excluded equipment items.
Based on the sample review, the staff determined that the excluded items were representative of the equipment found in the experience
- database, appeared to be adequately
- anchored, and were generally free of seismic interactions.
In one case, the staff noted a valve, CV-4-1607, that was very close to other equipment.
The staff questioned the licensee as to the potential for seismic interaction, and the impact on the safe shutdown path.
The licensee indicated that potential impacting or minor damage of the valve was acceptable, and that even if the valve failed to operate, it would not prevent achievement of safe shutdown.
Based on this sample review of excluded equipment items, the staff did not identify any significant concerns and this item is closed.
~Racewa a
The Turkey Point electrical
- raceways, including the associated supports and anchorages, were not evaluated by the licensee's Seismic Review Team (SRT).
In the 1983-84 time frame, the licensee developed and implemented a
comprehensive program to determine the as-built routing of all cables, loads on the raceway supports, and identify overfilled raceways.
The information developed as a result of this program provided a database for the control and documentation of future additions and rerouting of the cables.
The cable tray supports in the cable spreading room were qualified for 60X fill or existing percent fill, whichever controlled the design.
The remaining cable trays, including those in the Unit 3 and Unit 4 containments were evaluated for 40X" fill, or existing percent fill, whichever governed the design.
All safety-r'elated
- raceways, as well as seismic Category II over I raceways were evaluated for dead loads, plus seismic loads.
In the 1990-91 time frame, the licensee added a new Emergency Diesel Generator Building.
During that time, some of the cable trays were further loaded and some of the cables were rerouted.
The licensee had reevaluated the affected cable trays to assure compliance with the established criteria for filling, and seismic adequacy.
The staff reviewed the licensee'.s documentation identifying the cable trays, tolerable fill levels, and actual fill levels.
Drawings and calculation documents containing details and the design criteria used by the licensee's consultant, were also reviewed.
The staff randomly picked four cable tray runs (I) one in the Cable Spreading room at Elevation 30 ft., (2) one in the '
Control Room at Elevation 42 ft., (3) one in the Auxiliary Building at Elevation 18 ft., and (4) one in the Turbine Building at Elevation 30 ft.
Adequate documentation was available leading to the corresponding drawings and calculations packages.
The calculation packages led to the details about the supports and support anchorages.
The review of the criteria for supports design indicated that the licensee had used the l980 edition of the American Institute of Steel Construction specification with almost the same acceptance criteria as those in Standard Review Plan (SRP) 3.8.4.
However, for the combination of dead load with the Operating Basis Earthquake
[OBE, Peak Ground Acceleration (PGA)aa 0.05g], the licensee used the more liberal acceptance criterion of 0.72 Fy (yield stress) rather than 0.6 Fy.
For the combination of dead load with the Safe Shutdown Earthquake (SSE),
(SSE, PGA 0.15g), the licensee utilized the SRP acceptance criterion of 0.9 Fy.
This was acceptable since the combination with the OBE loading would not control the design of the supports since the ratio between the SSE and the OBE is larger than their corresponding acceptance criteria.
The staff also'eviewed the specifications and acceptance criteria for expansion bolts which were widely used in anchoring the supports to the concrete.
The installation procedure required the specific preload on the installed bolts, and the quality assurance criteria required the licensee to document the preload on the bolts.
During the walkdown of the four cable-tray runs, the staff review d th bl-tra ali y
'gnments, support spacings, and anchorages to the steel and concrete i
e 'ca e-structures.
The as-observed attributes were very close to the ones shown on the drawings.
Many of the cable trays and conduits had sprayed-on fire proofing.
The non-sprayed supports were painted.
The anchor bolts appeared to be sufficiently tight (observed and prodded with fingers).
- Overall, based on the review of the criteria, documentation, and inspection of the sampled cable trays, the staff concludes that the licensee was able to reasonably ensure that the over-fill conditions did not exist; and the cable trays, their supports and anchorages could safely withstand the postulated seismic loadings.
This item is closed.
SE Item 4 Staff's verification, by sampling, that the criteria in EPRI NP-5288-SL, Revision I, has been adequately addressed, in light of the extensive use of SRT judgment for screening out equipment anchorage and the lack of documentation to support the judgments.
Audit Observations and Findin s During the audit, the SRT members, who were technical reviewers or otherwise knowledgeable of the Electric" Power Research Institute (EPRI) anchorage criteria, confirmed that they applied the same criteria in judging anchorage adequacy for Turkey Point.
Since the plant was in an operating condition at the time of the audit, the staff could not comprehensively inspect the installed anchorage.
The staff performed limited walkdowns, and reviewed relevant design drawings and original design calculations.
In addition, the staff reviewed the licensee's supplemental calculations used to verify the adequacy of the installed anchorage, and also reviewed calculations to support anchorage modifications.
Based on this review, the staff raised questions regarding some of the existing anchor ages that the licensee previously determined were adequate, and on some of the anchorage modifications.
In one case, the staff questioned the adequacy of the upgraded anchorage for.
the 480 volt motor contro.l centers (MCC).
Specifically, the staff was concerned that only the front bottom portion of the HCC was anchored to the
.floor, and the front top was braced to the wall with steel angles at relatively large spacings.
This concern was discussed with the licensee and the SRT.
The SRT reviewed the seismic loads on the MCC.
The HCC is mounted at grade elevation and the SRT determined that the seismic loads were small.
The SRT therefore concluded that the modified anchorage was sufficient to carry the seismic loads.
Based on the review of the seismic loads and discussions with the SRT, the staff concurred with this conclusion.
5 In another
- case, the staff raised questions regarding the adequacy of the anchorage for the invertors and battery chargers.
Specifically, it was not clear if the anchor bolts penetrated through the 2.5-inch thick grout pedestals, and whether there was adequate embedment in the floor slab.
Further investigation revealed that the anchors consisted of new Hilti-type bolts with minimum embedment lengths of 8.5 and 12 inches, respectively.
The lengths of the bolts ensure a minimum embedment of 6. inches which the staff determined was adequate for the light equipment.
The staff noted a crack on the concrete floor in front of the Unit 4 Direct Current Load. Center.
The staff was concerned that the crack may propagate through the pedestal near the anchor bolts, and could degrade the load carrying capacity of the bolts.
Subsequent investigation by the licensee confirmed that the crack had indeed penetrated the pedestal and passed near one of the two bolts in the middle row.
The licensee indicated that the remaining five bolts can safely carry the seismic loads from the cabinet.
However, the staff remained concerned that the crack could worsen and further degrade the anchorage capacity.
In response to the staff's concerns, the finding was documented in the licensee's deficiency tracking system as Condition Report 95-1220 for corrective action.
The licensee's corrective action will be evaluated in the NRC resident inspector's report.
- Thus, based on confirmation by the SRT and the staff's own sample audit and inspection, the staff found that the equipment anchor ages are adequate for the seismic loads at turkey Point except for the two places as noted below.
The component cooling water heat exchangers and associated support
- systems, and several other equipment items, all located in an area of the plant which de is exposed to the outside environment, were observed to have been sever 1
graded by corrosion (e.g., bolt heads were split and-steel plates were perforated).
Although the staff did not consider this to be an immediate
- problem, the staff was concerned that further degradation could challenge the structural integrity of the supports.
It was also noted that in several
- cases, the licensee appeared to have recently painted some of the corroded structures, but the corrosion products had not been removed.
This may not arrest further corrosion, and may require more aggressive maintenance for prolonged reliance on these items for carrying seismic (and other) loads.
The
.staff cautioned. the licensee that it would be prudent to implement a program for eliminating and controlling corrosion.
The licensee documented the as-found condition of the equipment, that it would perform further evaluations of the equipment, and that it would implement corrective actions to arrest further corrosion.
This was documented in the licensee's deficiency tracking system as Condition Report 95-1217 for corrective action.
The staff considers the licensee's action sufficient to close this item.
The licensee's corrective action will be tracked in the NRC's resident inspector's report.
SE Item 5 Staff's verification, during the site audit, of the adequacy of the licensee's implementation of the methodology for assessing seismic interactions.
F
Audit Obse vations and Findin s During discussions with the staff, the SRT members confirmed that during their walkdown in 1990, they specifically considered the potential for spatial interaction of components due to seismic motion.
- Further, the SRT members indicated that the seismic interactions assessment was consistent with the methodology approved for the USI A-46 generic resolution.
The methodology consists of visual inspection of the existing clearance between adjacent components, and assessing whether modifications were needed to limit seismic motion to prevent deleterious interactions.
During the site audit, the staff observed that the licensee's program was generally effective in identifying and resolving potential seismic inter action situations, or ensuring that an interaction concern does not exist.
- However, the staff also noted some instances in which the potential for seismic interaction still existed.
For example, during a walkdown of the station batteries, the staff noted small clearances between some of the end battery cells and restraints, and between some interior battery cells and vertical cross braces.
These clearances could result in damage due to the batteries impacting the restraints and support structures.
This situation was previously noted by the SRT during its equipment walkdowns, but the licensee had failed to address the concern.
The staff informed the licensee that either these gaps should be eliminated or spacer cushions should be inserted to eliminate the potential for impact of the brittle battery cells with the restraint's metallic material.
The licensee indicated that it would implement corrective actions to resolve the concerns with the batteries.
This was documented in the licensee's deficiency tracking system as Condition Report 95-1217 for corrective action.
Another potential seismic interaction concern involved the medium voltage switchgear.
The staff noted that several screws on the doors of the cabinets were either missing or loose; which could result in rattling of the doors.
These cabinets house electrical relays, and rattling of the doors could cause chatter or relay malfunction.
The staff considers this as primarily a housekeeping issue.
Since electrical cabinet doors are frequently opened for maintenance and operational
- purposes, the licensee should institute and adhere to a good housekeeping program that will ensure securing all door fasteners for all cabinets.
In response to the staff'
- concerns, the licensee indicated that it would review the adequacy of its housekeeping procedures, and ensure that plant maintenance and operations staff are aware of the importance of proper housekeeping.
This was documented in the licensee's deficiency tracking system as Condition Report 95-1217 for corrective action.
The staff finds that the licensee's implementation of the methodology for accessing seismic interactions is acceptable and considers the licensee's commitment to resolve the above concerns sufficient to close this item.
The licensee's corrective ac%on will be tracked in.the NRC's resident inspector's report.
SE Item 6 Staff's review of the capacity versus demand evaluations for selected equipment items to confirm the appropriateness of the licensee*s method of comparing capacity and demand at the plant level rather than for each individual equipment item.
Ct i
Audit Obse vat o s and din s For the USI A-46 program, the equipment capacity is usually derived generically by use of the experience data.
The Senior Seismic Review and Advisory Panel (SSRAP) has developed a generic capacity spectrum (called "reference spectrum,"
having 1.2g spectral acceleration between 3 and 8 Hz at a damping value of 5X with a zero period acceleration of 0.5g) -for common types of industrial equipment ~ long as certain inclusion and exclusion rules are satisfied.
The SSRAP recommended that the seismic ground motion demand should not exceed two-thirds of this capacity spectrum (called "bounding spectrum").
- Further, the SSRAP judged that this demand vs. capacity comparison is valid for equipment located at an elevation equal or less than about 40 feet above the effective grade as long as the building is a typical industrial structure and the equipment items possess a fundamental frequency above about 8 Hz.
Otherwise, the in-structure response spectrum at the equipment mounting location should be used for comparison with the capacity spectrum.
For Turkey Point, the SSE ground motion acceleration spectrum with a zero period acceleration of 0. 15g is substantially below the bounding spectrum.
Equipment items in the licensee's USI A-46 safe shutdown list (except component cooling water surge tanks that have been separately evaluated) are located at an elevation of 24 feet or less above the effective grade.
Thus, the amplification of the ground motion will be such that the amplified in-structure acceleration response spectra at 5X damping up to this elevation will be significantly lower than the reference spectrum.
This was confirmed during the audit by comparing with the in-structure spectra response available for the Control Building.
Therefore, this item is closed.
SE Item 7 Staff's review of the licensee's evaluation of tanks and heat exchangers to verify the adequacy of the licensee's calculations, and to ensure that the program adequately resolves the outliers and concerns identified in the SE.
The review is for resolving the seismic adequacy of tank's in both USI A-40 and USI A-46.
Audit Observations and Findin s l.
Yard Tanks Refuelin Water Stora e Tank and Condensate Stora e Tank During this audit, the staff discussed the deficiencies in the seismic capacity of the Refueling Water Storage Tank (RWST) and Condensate Storage Tank (CST) with the licensee and its consultant
[Stevenson 5 Associates (SM)].
As a result of the recommendation of the SRT and SM, the licensee upgraded the tops of the tank chairs.
With the upgr ade, and using relatively conservative criteria, the licensee calculated the tank capacities as 0. llg.
The capacities are controlled by the capacity of the J-bolts used for anchoring the tanks to thh concrete ring foundations.
Subsequent to the audit, the licensee attempted to demonstrate that the realistic high, confidence-low probability of failure-(HCLPF) capacities were higher than the SSE PGA (0. 15g).
By letter dated June 20,
- 1996, FPL indicated that the seismic capacities of the CSTs and RWSTs met the design basis seismic acceleration requirement of 0. 15g ground acceleration for the maximum hypothetical earthquake, i.e.,
- SSE, and the tanks were no longer considered outliers.
A review by the staff's consultant, BNL, indicated that the formulas used by. SM could not be undisputedly substantiated, and when more conservative formulas were employed, the tanks'CLPF capacities could be
I'
estimated to be 0.12g.
The staff recognizes that BNL computed HCLPF capacity values for the tanks are based on conservative design code assumptions, and that they were sufficiently close to SSE-PGA.
Thus, the staff concludes that the tanks are capable of withstanding the postulated earthquakes without losing their fluid content.
2.
Boric Ac d Stor e Tanks The original design documentation for the Boric Acid Storage Tanks (BASTs) was not available.
Ouring the SRT walkdown in 1990, the team identified the anchorage of vertical tank support legs, welds, and the torsional load on horizontal support system as concerns.
However, in l991, the licensee made a
change in the concentration of boric acid in the tanks, and increased the depth of boric acid in the tanks.
To incorporate the effects of the change, and to address the SRT's seismic concern, the licensee reanalyzed the tanks and their support structures.
The reanalysis was performed by ABB Impell Corporation (the licensee's consultant) after surveying the as-built conditions of the tanks and their support structures.
The preliminary analysis indicated that the support systems required six rigid vertical struts attached at specified locations to the supporting horizontal members (existing 12W58 and 12W65) that are anchored to the Auxiliary Building South wall.
The licensee installed the'truts.
ABB Impell performed the dynamic analysis of a tank model, and the integrated support structures.
The details of this analysis was provided to the staff subsequent to the site audit in Oecember 1995.
The staff reviewed the parameters incorporated into the dynamic analyses, their results, the way the results were incorporated in verification of the adequacy of the tanks, their attachments, and the support structures.
The staff also performed a sample review of the calculations related to the North 'side columns (where struts were not added),
and found them to be slightly (maximum 7X) overstressed.
ABB Impell provided a number of reasons (mainly conservative analysis-design assumptions) for accepting the minor overstress.
The staff did not completely agree with all the reasons
- provided, but overall, the staff considers the small overstress acceptable.
Based on the SRT's walkdown and the staff's review and walkdown inspection, the staff concludes that the BASTs and their support structures, as modified, are adequate to withstand the postulated seismic loadings.
This item is therefore closed.
SE Item 8 Staff's review of specific seismic qualification documents for the "Bad Actor" relays and the adequacy of procedural changes and/or operator actions for resetting relays.
Audit Observations and Fthdin s
'he FPL reduced-scope relay program includes verifying relay mounting (see 2/9/95 SE Item No. 9),
and disposition of any relays on the EPRI "Bad Actor" list that are installed in the plant.
The "Bad Actor" relays are so defined because of documented past poor performance, the basis of which varies due to severa1 factors.
FPL reviewed the relays installed at Turkey Point, and found that of the 23 "Bad Actor" relays on the EPRI list, the following relays are used in Turkey Point Units 3 and 4:
I '
GE Relays
- CFD, CFVB, CEH, IJD, HGA and PVD
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g Relay SG
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Mercury Switches
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Sudden Pressure Switches The licensee initially indicated that it had specific seismic qualification data to qualify some of the "Bad Actor" relays installed at Turkey Point.
The staff reviewed the test data during the audit, and questioned whether the data'as sufficient to demonstrate adequacy of these relays in all of the different applications.
A major concern was that FPL did not fully assess the potential for different in-structure responses due to the plant elevation at which the relay was installed, and the specific mounting configuration.
Therefore, the actual in-structure response spectra for a particular relay may be higher than the test response spectra.
Consequently, the staff did not accept the licensee's position that a single test report could be used to demonstrate the adequacy of one type of relay in all applications.
In response to the staff's concerns, the licensee performed additional evaluations to determine the effect that potential seismic-induced chatter may
, have on the ability of the relay to perform its safe shutdown function.
The licensee provided information to demonstrate that potential relay chatter of "
the "Bad Actor" relays would not affect the ability to achieve safe shutdown."
The licensee determined that most of the "Bad Actor" relays installed at Tur key Point perform annunciation functions, and have no direct safety function.
For the remaining relay types, the licensee determined that chatter can be tolerat'ed for each particular application.
There is one "Bad Actor" relay model (GE IJD) installed at Turkey Point for which the earthquake experience data showed a unique failure mode due to seismic loads.
This is an induction disk relay and is installed at Turkey Point in the emergency diesel generator control panel.
The experience data showed an instance in which the relay control spring vibrated due to seismic
- loads, touched ground within the relay enclosure, and short-circuited the relay.
During discussions with the licensee, an SRT member provided information to show that this particular failure mode was, not a concern if the relay included a special restraining device to prevent excessive spring vibration.
The GE IJD relays installed in the safe shutdown path at Turkey Point were inspected and found to contain the special device.
Therefore, this failure mode is not applicable to this type of relay installed at Turkey Point.
Notwithstanding, the licensee performed further assessment of the possible failure of this relay, and concluded that operator actions would be sufficient to ensure that safe plant shutdown would be accomplished.
In order to provide an afditional level of defense-in-depth against deleterious effects of relay chatter, the licensee indicated that its Emergency Plant Implementation Procedure would be revised to alert plant operators of the possible occurrence of relay chatter, and to provide guidance for identifying and recovering from potential relay chatter.
The staff concluded that the licensee's actions appeared adequate to resolve the concerns with "Bad Actor" relays, and therefore, the "Bad Actor" relay issue is closed.
10 SE tern 9
Staff's verification, by sampling of the installation adequacy of relays in the safe shutdown path.
Audit Observations and Findin s In general, since the plant was at ful,l power during the audit, electrical and
'control cabinets could not be opened for verification of relay mounting.
This subject was discussed with the SRT members who confirmed that, during their equipment walkdowns in 1990, they verified that relays were adequately mounted.
For the limited occasions when the licensee opened the cabinets during the audit, the staff inspected relay mountings and did not observe any mounting configurations that would contradict the SRT's observations.
In addition, the licensee implemented a relay inspection program which verified the installation adequacy of a sample population of relays in the safe shutdown path.
This program included visual examination of numerous relay installations, and additional relays were selected for physical examination to verify that mountings were secure.
The staff reviewed the results of this program.
The licensee reported that all relays inspected were determined to be properly installed per manufacturers recommendations.
The staff concluded that the actions described above provide reasonable assurance that relays in the safe shutdown path are adequately installed, and therefore, this item is closed.
SE Item 10 Staff's review of the licensee's methods for resolving equipment outliers, including any needed revisions to plant procedures to address the several issues involving poor housekeeping.
Audit Observations and Findin s For many of the modifications which were implemented to resolve equipment
- outliers, the staff observed that the modifications were adequate.
- However, there were also instances in which the licensee did not implement a
modification recommended by the SRT, or in which it was not clear that the modifications adequately resolved the issues.
For example, the licensee failed to address the SRT's recommendation to replace a sight glass on the emergency diesel generator day tank.
The SRT's concern was that the glass may break during a seismic event and result in draining the day tank.
The licensee's options were either to replace the glass with a different material (e.g., plastic) not prone to breakage, or demonstrate that the consequences of losing the sight glass are acceptable.
The licensee initiated Condition Report 95-1219 to document the site glass deficiency for corrective action.
Subsequent to the audit,~the licensee indicated that the lower gage glass isolation valve is an excess flow stop check valve which would minimize fuel losses in the event of a site glass rupture.
Documentation for this valve will be reviewed by the resident inspector.
The lack of spacers for batteries (SE Item 5) presents a potential seismic interaction concern that was originally identified by the SRT.
In the case of modifications made to the HCC, it was not immediately clear whether the anchorage modifications adequately addressed the SRT concern.
During the audit, the SRT performed further calculations and determined-.that the modifications were adequate since the HCCs are located at the grade level.
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During the equipment walkdowns, the staff identified several examples of poor housekeeping and inadequate maintenance.
For example, the staff identified loose fasteners
- and, in some cases, lack of fasteners for securing some electrical cabinet doors (SE Item 4).
The staff also observed severe corrosion of outdoor components and cracking of the concrete floor slab near an electrical cabinet (SE Item 4).
The staff considers these observations indicative of the need for the licensee to more closely focus on improving its housekeeping and equipment maiptenance programs.
The licensee indicated that it would take appropriate actions to resolve the specific issues.
The staff concluded that the licensee needs to improve its initiatives and methodologies for resolving outliers, and needs to improve its housekeeping program.
The staff understands that the licensee is currently addressing all of the deficiencies and outliers identified during the site audit by the Condition Reports previously mentioned.
On this basis, this SER item is closed.
- However, the above-identified staff findings and subsequent licensee's corrective actions relating to this item will be tracked by the NRC's resident inspector.
~ 3. 0 CONCLUSIONS As described in this SE, the staff found that, in general, FPL has implemented an adequate seismic program to address the open items described in the staff's SE dated February 9,
1995.
- However, the staff identified several items for which the licensee needs to take additional actions to resolve the staff's concerns.
These items are summarized below.
2.
The concrete floor crack observed near the Unit 4 DC load center should be repaired (SE Item 4).
Better maintenance needs to be provided, especially, to steel components located outdoors, to arrest further degradation due to corrosion (SE Item 4).
3.
Cushioning materials should be provided at the end and between battery cells to preclude potential impacting for the station batteries (SE Item 5).
4.
The licensee should institute and implement a strict housekeeping program to preclude the types of situations identified during the audit; e.g., electrical cabinet doors should be secured and locked with all of the fasteners provided with the equipment items (SE Item 5, 10).
During the exit meeting held on December 8,
- 1995, the licensee's management acknowledged the items summarized above.
The licensee stated its commitment, to resolve these items.
On the basis of the licensee's commitment, the original SE items are co%sidered closed.
- However, the licensee's corrective actions will be followed and tracked by the NRC's resident inspector.
The corrective actions were reviewed by the Project Manager. during a site visit on September 30 through October 2,
- 1996, and are dicussed in Inspection Report 50-250/251 96-12.
4.0 CONCLUSIO S
FOR ST.
LUCIE UNIT 1
12 Based on the results of the Turkey Point Units 3 and 4 inspection, the staff determined that a separate inspection at the St.
Lucie Unit 1 is not warranted.
However, in addition to the general concerns common to these three units, the staff's February 9,
- 1995, SE, identified two areas of concerns specific to St. Lucie Unit 1, namely (1) poor seismic housekeeping (Section 2.3),
and (2) adequacy of safe 'shutdown tanks and heat exchangers (Section 2.4).
Considering that the SSE for St.
Lucie Unit 1 is less than that. for Turkey
- Point, and based on the resolution of the tank issue at Turkey Point, the staff considers the tank issue at St. Lucie Unit 1 closed.
With regard to the housekeeping
- issue, the licensee should institute and implement a strict housekeeping and maintenance program similar to that considered for Turkey Point Unit 3 and 4 (Items 2 and 4), to preclude the types of findings identified by the SRT and exemplified in the staff's February 9, 1995 SE.
This SE item is considered closed;
- however, the licensee's corrective action will be tracked by the NRC's resident inspector.
On the basis of the above, all the original SE open items for St.
Lucie Unit 1're considered closed.
Principle Contributors:
H. Ashar, M. HcBrearty, P.Y.
Chen.
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