IR 05000395/1991002
| ML20029C071 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/08/1991 |
| From: | Cantrell F, Haag R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20029C069 | List: |
| References | |
| 50-395-91-02, 50-395-91-2, NUDOCS 9103250230 | |
| Download: ML20029C071 (10) | |
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UNITED ST ATES jepmMo o
NUCLEAR REGULA10RY COMMisslON o
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REGION ll n
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101 MARIETTA STREET, N.W.
- c ATLANi A. GEORGI A 30323
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Report No.:
50-395/91-02 Licensee:
South Carolina Electric & Gas Company Columbia, SC 29218 Docket No.:
50-395 License No.:
NPF-12 Facility Name.
V. C. Summer Nuclear Station Inspection Conducted:
February 1 - 28, 1991 k T hl dd)M 3/7/?/
Inspector:
R. C. Haag, Senior ResGdent Inspector Date Signed Accompanying Personnel:
L. A. Keller
I Approved by:
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4 hFlopdS.Captrell,SectionChiei Date Signed Reactor Projects Branch 1 Division of Reactor Projects SUMMARY Scope:
This routine inspection was conducted by the resident inspectors onsite in the areas of monthly surveillance observations, monthly maintenance observation, operational safety verification, ESF system walkdown, review of nonconformance reports, and onsite follow-up of written reports of nonroutine events at power reactor facilities.
Selected tours were conducted on backshift or weekends.
Results:
At the beginning )of the insoection period, the plant was operating at reduced power (75 percent for fuel conservation and to allow continued plant operation for this fuel cycle until the next scheduled refueling outage in September, 1991.
Power was increased to 99 percent on February 4,1991, and remained at that pcwer level through the remainder of the inspection period.
- A potential safety hazard involving a temporary electrical cord lying in water and in an area with several ongoing maintenance activities was brought to the licensee's attention. An ESF system walkdown of the RB spray system identified several minor deficiencies.
The licensee initiated prompt corrective action for these items.
Resolution of a question by the inspector concerning applicable loads and stresses on the RCP motor oil cooler nozzles was timely and thorough.
l 9103250230 910308 PDR ADOCK 05000393 Q
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REPORT DETAILS 1.
Persons Contacted Licensee Employees W. Baehr, Manager, Chemistry and Heal +h Physics
- C Bowman, Manager, Maintenance Services
- M. Browne, Manager, Systems Engineering & Performance
- R. Campbell, Senior Engineer, Technical Oversight B. Christinsen, Manager, Technical Services
- H. Donnelly, Senior Engineer, Nuclear Licensing S. Furstenberg, Associate Manager, Operations
- G. Gibson, Manager, Nuclear Protection Services D. Goldston, Supervisor, Test Unit
- G. Hall, Associate Manager, Health Physics
- W. Higgins, Supervisor, Regulatory Compliance
- A. Koon, Manager, Nuclear Licensing-D. Moore, General Manager, Station Support H. O'Quinn, Associate Manager, Maintenance Services
- C, Price, Manager, Technical Oversite
- J. Proper, Associate Manager, ;Jality Serv'ces
- M. Quinton, General Manager, Eagineering Services
- L. Shealy, Senior Engineer, ISEG J. Skolds, Vice President, Nuclear Operations
- G.. Soult, General ~ Manager, Nuclear Plant Operations
- G. Taylor, Manager, Operations
- F. Zander, Manager, Nuclear Technical Education & Training Other licensee employees contacted included engineers, technicians, operators, mechanics, security force members, and office personnel.
- Attended exit interview Acronyms and initialisms used throughout this report are listed in the last paragraph.
Other Inspections:
An inspection by two regional inspectors of the licensee's radiation protection program was performed during the inspection perlod.
David M. ' Verrelli, Chief, -Reactor Projects Branch 1, visited the site on February 28-29, 1991, to meet with the resident inspectors, tour the plant, and review inspection activities.
2.
Monthly Surveillance Observation (61726)
The inspectors observed surveillance activities of safety related systems l
and components to ascertain that these activities were conducted in l
accordance with license requirements. The inspectors observed all aspects
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of Service Water Pump B Test, STP 123.002, and portion of the tests listed below.
The inspectors verified that required administrative approvals were obtained prior to initiating the test, testing was accomplished by qualified personnel in accordance with an approved test procedure, test instrumentation was calibrated, and limiting canditions for operation were met.
Upon completion of the test, the inspectors verified that test results conformed with technical specifications and procedure require-ments, test results were reviewed by personnel other than the individual directing the test, any deficiencies identified during the testir.g were properly reviewed and resolved by appropriate management personnel, and the systems were properly returned to service.
Semi-annual leak :est of the reactor building purge supply valves
XVB0001A and B (5P 115.022)
Main steam valves aperability test (STP 121.002)
Remote shutdown parel instrumentation channel check (STP 113.001)
Monthly test of
"B" service water booster pump (STP 123.002).
At the
completion of the test when securing SW flow to the reactor building cooling units, the inspector noted a difference in the sequence given in the STP and the industrial cooling water SOP.
STP 123.002 directed stopping of the booster pump then closure of the SW return valve while S0P 125 directed closure of the return valve prior to stopping the pump.
The inspector questioned the licensee on the desired sequence for securing SW flow to the RBCU's.
The licensee is reviewing this issue.
Valve stroke testing of
"B" RHR pump minimum flow isolation valve
FCV0602B (STP 105.005)
Monthly operational test of the reactor coolant pump under voltage
ans under frequency reactor trip actuation device (STP 506.002)
' Movable control rod insertion test (STP 106.001).
After moving each
rod bank back to it's original position, step 6.3.m of the STP directs that the Rod Control Bank Selector switch be placed in manual.
The following step (6.3.n) required the adjustment of Tavg by using manual rod control until the difference between Tavg and Tref is less than one degree Fahrenheit, then the selector switch is placed in Auto.
During the actual STP when each bank was individually moved, the difference between Tavg ard Tref remained less than one-degree Fahrenheit and therefore Tavg did not require adjustment by using manual rod control.
The inspector noted that the STP does not provide the flexibility for the operator to determine if the selector
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switch should be placed in manual for Tavg adjustment or if the switch can be directly placed in Auto. The licensee is reviewing the STP to determine if a procedure improvement is needed.
Operability test of chill water non-cssential isolation check valve
XVC06387A (STP 129.002)
No violations or deviation; were identified.
3.
Monthly Maintenance Observation (62703)
Station maitienance activities for the safety-related systems and components listed below were observed to ascertain that they were conducted in accordance with approved procedures, regulatory guides, and industry codes or standards and in conformance with TS.
The following items were considered during this review:
Limiting condi-tions for operation were met while coinponents or systems were removed from service, approvals were obtained prior to initiating the work, activities were accomplished using approved procedures and were inspected as applicable, functional testing and/or calibrations were performed prior to returning components or systems to service, cuality control records were maintained, activities were accomplished by qualified personnel, part.s and materials used were properly certified, and radiological and fire prevention controls were implemented.
Work requests were reviewed to detennine the status of outstanding jobs and to ensure that priority was assigned to safety-related equipment maintenance thct may affcct system performance.
The following maintenance activities were observed:
Preventive maintenance on the limiterque operator for the component
cooling water non-essential header itolation valve V.VB9526B (PMTS P0141045)
Replacement of Agastct relay, H6?XVU3A, which was located in the
start circuitry for the "A" chiller auxiliary oil pump.
Due to agiug concerns, replacement of the relay is scheduled on a three year time interval.
While observing the relay work, the inspector noted that the mechanics had connected.an external water heater to the chiller.
The heater was used to raise the temperature and pressure of the chiller refrigerent (freon) to allow subsequent work on the chiller.
The inspector noted that the electrical power supply cord to the 120 volt pump associated with the water heater was lying in water -that had drained from the chiller.
This potential safety hazard was brought to the attention of the licensee and the need for additional safety precaution when using ttmporary power supplies. The licenste innediately corrected this safety concern.
Inspection and testing of "A" chill water pump circuit breaker
XSW10A2-06C (EMP 295.004)
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1 Preventive maintenance on the limitorque tperator 'or "B" RHR heat
exchanger component cooling water inlet valve XVB95038 (PMTS PW42648)
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Cal 1bration of various gage::, pressure switches and temperata/c
switches associated with
"A" chill water chiiler XHX IC (PMTS P0141814)
Repair of nir leak on regulator for mairi sterm power operator relief
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valve operator IPV2020 (MWR 9100365)
Annual inspection and pa rtial teardewn of "B" emergency diesel
generator air compressor XAC0080 (PMTS P0141120)
Removal of chilled water non-esseritial i solation check valves XVC6410A and XVC6489A INCN 4096).
During operab('lity testing of
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'XVC6410A tne ddfferential pressure across the valve failed to meet the STP acceptance criteria.
The licensea also quantifi9d the leakage past the check valve.
Disassembly of ttu valve d'd not identify the cause of leakagt.
Subsequent test.ng af ter Jalve reassemoly also failed.
Since the non-essential portions of the VU system are no longer in use ar.d flow through the check valve is not required, the licansee tack welded the disc to the seat to prevent leakage thrcugh. XVC64'10A.
However, the following leak test also failed.
As part of the VU system upgrade the licensee had planned to isolate the non-essential portions of the system from the s*ty related part of the system and to provide a separate chiller for the non-essential loads.
Based on tiie unsuccessful attempts to correct the seat leakage, the licensee implemented a portion of the upgrade modifica-tion that involved removal of the isolation check valves -(XVC6410A and XVC6489A) and welding caps on the remaining piping, The inspector
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l observed portions'of this work that wes completed per MRF 34096.
The application of a freeze seal which allowed a significant reduction in the amount of VU piping subjected to hydrostatic testing was also observed.
Subsequently, the licensee also removed the two sets of
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isolation check valves that are located in the "B" train of the YU system.
No violations or deviations were identified.
I 4.
Operational Safe'v Verification (71707)
The inspectors conducted daily inspections in the following areas:
control room staffing, access, and operator behavior; operator adherence to approved procedures, TS, and lhiting conditions for operations;
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l examination of' panels containing instrumentation and other reactor l
protection system elements to determine that required channels are
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f operable; and review of cont col room operator logs, operating orders,
- ' ant deviation reparts, tageat logs, jumper logs, and tags on components varify complia me with approved procedures.
e Tho inspectors conducted weekly inspections in the following areas:
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ice ification of operability of selected ESF systems by ) valve alignment, k:
breaker positions, condition of equipment or component (s, and operability y
of instrumentation and support itens essential to system actuation or
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performance.
Plant tours included abservation of general plant / equipment conditions-fire protection and preventative measures, control of activil'^s N y
progress, radiation protection controls, ohysical :,ecurity cc o rris, lanx
!g housekeeping conditions / cleanliness, and missile hazards.
g The inspectors conducted biweekly inspections in the follo.'rq nreas:
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verif cation review and walkdown of safety related tagout(s) in effect;
review of sampling progra.r. (e.g., primary and seC9tury cooiant samples, boric acid tank saaples, plant liquid and gaseous n u es); observa', ion of
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control room shif t turnover; Av b of (rplementation u,
the nlart piobler i le stification system; verificat ion of selected portians of certainment isciation lineup (s); and verificction that notices to workeh. are peiled as required by 10 CFR 19.
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Selected tours were conducted on backshif ts or yeekend:.
Inspections included areas in the cable vaults, vital battery rooms, safeguards arbasy i
emergency switchgear rooms, diesel g merator rooms, control rcom, auriliary tuilding, cable penetration areas, service water intake structure, and cttar general plant areas.
- ates w4re reviewed to ensure that detected or suspected leakage from the system ieas recorded, hvastigated, and evaluated; and that appropriate actions were taken, if required.
On a regular basis, RWP's were reviewed and specific work activities were monitored to assure they were being conducted per the RWP's.
Selected radiation protection instruments were
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periodically checked, and equipment operability and calibration frequency were verified.
In the course of monthly activities, the inspectors included a review of the licensee's physical security program.
The performance of various shifts of the recurity force was observed in the conduct of daily
activities to incicde:
protected and vital areas access controls; s9:archirq cf perscanel, paci: ages and vehicles; badge issuance and mtrievM; esco'eting >of visitors; and patrols and compensatory posts.
K] vi6tations cr deviations ' sere identified.
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5.
ESF System Walkdown (71710)
The inspectors verified the operability of on ESF system by performing a walkdown of the accessible portions of the reactor building spray system.
The inspectors checked the licensee's system line-up procedures against plant drawings and the as-built configuration. The inspectors looked for equipment conditions and items that might degrade performance (i.e.,
corrosion, housekeeping, etc.).
The inspectors verified that-valves, including instrumentation isolation valves, were in proper position, power
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was available, and valves were locked as appropriate.
1he inspectors
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compared both local and remote position indications.
The inspectors verified that instrument calibration dates were current.
During the walkdown inspection, several minor defb.tencies were identified, including a discrepancy between the licenst e's valve line-up checklist and the as found condition.
The licensee reviewed thes3 items and issued c
l appropriate corrective action.
i No violations or deviations were identified.
6.
Review of Nonconformance Reports (71707)
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NCNs and ON0s were reviewed to verify the following:
TS were complied with, corrective actions bs identified in the reports were accomplished or i
being pursued for completion, generic items were identified and repcrted,
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and items were reported as required by the TS.
NCN 4038 identified an excessive loading condition for the RCP motor uppe:
bearing oil cooler nozzles.
The normal design conditions for all three cooler outlet nozzles and one cooler inlet nozzle resulted in stresses that were above ASME code allowables.
With the addition of seismic loads, the stresses for all the nozzles exceeded the vendor's and code allowables.
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The inspector reviewed the NCN evaluation which accepted continued plant operation with current RCP oil cooler nozzle loads.
The evaluation concluded that for normal loads (caused by thermal growth)- failure of the inlet nozzles would not occur and failure of the outlet nozzle was extremely un19Nli due to the limited number of RCP thermal cycles.
For a seismic event which would increase the likelihooo of a nozzle failure, the i
evaluation showed that failure of a cooler nozzle would not adversely affect the safe :hutdown of the reactor nor degrade the performance of the
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i essential portions of the CCW system.
During the revier the inspector noted that the cyclic loading from the RCP vibration had not been addressed in the evaluation, in response, the licensee agreed that vibration from the RCP's, which had not been included in the evaluation, should be considered in the overall loading and stress analysis for the RCP cooler nozzles. Westinghouse performed a subsequent
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fatigue crack growth analysis which included stresses due to both opera-tibaal transients (normal heatup and cooldown) and RCP vibration.
The
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evaluation concluded that RCP vibration had no effect on crack growth.
Based on these evaluations, the licensee's decision to correct the nozzle refueling outage (Spring of 1993)g flexible hose during the seventh loading conditions by installin appears appropriate.
Onsite Follow-up )of Written Reports of Honroutine Events at Power Reactor 7.
Facilities (92700 The inspectors reviewed the following Part 21 Reports, LER's and SPR's to ascertain whether the licensee's review, corrective action and report of the identified event or deficiency was in conformance with regulatory requirements, TS, license conditions, and licensee procedures and controls.
(Closed)
10 CFR 21 Report (P2189-12)), Part 21 report from Limitorque on SMB-000 and SMB-00 torque switch failures which result from loosening of contact screws which had fiber spacers.
The licentee's initial applica-bility review identified 30 non-safety and 5 safety related SMB-000 operators and no SMB-00 operators installed in the plant that may have fiber spacers in the torque switch.
Further review of the maintenance history narrowed the group dowa to one non-safety and two safety rf.ated SMB-000 operators that may have fiber spacers.
During this inspection period the torque switches of the two safety related operators were replaced with new style torque switches that do not contain fiber spacers.
Replacement of the torque switch for the non-safety related operator will be completed during the next refueling outage.
It should be noted that the licensee (SCE&G) did not receive tb Part 21 notification from Limitorque when the initial notifications were made to affected facilities in September, 1989.- The licensee became aware of the Part 21 notification in August, 1990, when the inspector questioned the licensee on the status of their Part 21 evaluation.
The licensee is pursuing this issue to ensure that they (SCE&G) are included on future Limitorque Part 21 notifications that are applicable to the plant.
(Closed)
10 CFR 21 Report (P2189-19), Part 21 report from Dresser Pump Industrics on improper hardening of replacement pressure reducing sleeves.
Failure of these sleeves would occur within one hour of pump startup and result in exCsive vivration and/or pump seizure.
Two independent-reviews con ted by tha licensee identified no spare pressure reducing sleeves ons.,e for -the charging / safety injection pumps.
In addition, information-on the potectlally defective sleeves will be included in the technical manual and procurement rNords for the pumps to' ensure that any future replacement sleeves do not contain the hardening defect.
(Closed)
Special Report 91-001, Degraded fire barrier between the auxiliary building and fuel-handling building exceeding the seven day limit.
The degraded barrier which was discovered during a scheduled fire barrier inspection was not repaired within the time limits due to the unavailability of a sufficient quantity of replacement foam material.
The
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a licensee reviewed the maintenance history and surveillance program for similar fire barriers and determined that the current inspection program is adequate to ensure compliance with the VCSNS fire protection program.
Based on the inspector's observations of the fire protection program
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implementation, this determination appears appropriate.
The degraded fire barrier was subsequently repaired.
(Closed)
LER 89-20. Reactor trip due to low steam generator water level caused by rapid turbine power decrease.
While decreasing power for the monthly turbine control valve testing, the turbine commenced a rapid power t
decrease.
After attempts by operators to stop the power decrease failed,
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the turbine was manually tripped.
The exciter field breaker f ailed to open af ter the turbine trip.
Later after ceveral attempts the breaker opened.
This breaker also failed to open following a reactor and turbine trip on February 16, 1988.
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The rapid turbine runback was caused by a relay contact failure in the turbine EHC circuitry.
A review of the runback circuit identified that a
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24 volt relay coil was connected to the failed contact without diodes which would have prevented high inductive voltages across the contact.
Failure of the exciter tield breaker to open resulted from a lack of lubrication, in addition to replacerent of the defective EHC card, the circuitry was modified by the installation of diodes.
A PM activity was
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initiated on a six month interval for the excitor field breaker.
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this event the licensee has not experienced any problems with the turbine runback circuit or failures of the excitor field bren er.
(0 pen) LER 89-16, Reactor shutdown due to an indication that "A" main isolation valve would not close.
Subsequent inspections identified that a crushed conduit containing the MSIV test circuit wiring was the cause of the erroneous indication that the MSIV would not close.
The crashed conduit resulted from movement of a feedwater flush line during a plant restart.
An engineering review of plant events prior to the MSIV indication concluded that a water hanmer transient caused the movement in a FW flush line. This review also determined that voiding occurred in the FW line after flushing was secured.
Then several hours later a change in tne valve lineup was made which allowed hot water (280 degrees Fahrenheit)
to refill the line and cause the water hammer-transient.
Engineering recomrnended several changes to the FW system 50P which would ensure that the flush line remained full af ter flushing operations and would prevent a similar transient.
When reviewing the FW system SOP, the inspector noted that the recommended changes had not been implemented into the SOP. _ Operations personnel were reluctant to use the same flush path that had caused the transient even with the changes recommended by engineering.- Therefore, to prevent recurrence, they maintain a valve in the flush path danger tagged-in the closed position.
The inspector agreed that maintaining this valve closed will prevent a similar water hanner i
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transient; however, changes to the FW system 50P are still being considered for implementation.
The item will remain open pending the licensee's permanent actions regarding future FW flushing evolutions.
8.
ExitInterview(30703)
The insp">: tion scope and findings were summarized on February 28, 1991, with those persons indicated in paragraph 1.
The inspectors described the areas inspected and discussed the inspection findings.
No dissenting comments were received from the licensee. The licensee did not identify as proprietary any of the matcaials provided to or reviewed by-the inspectors during the inspection.
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Licensee management was informed that two 10 CFR Part 21 reports and one LER discussed in paragraph 7 were closed during this inspection.
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9.
Acronyms and Initialisms ASME American Society of Mechanical Eng neors
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CCW Component Cooling Water EHC Electric Hydtaulic Control EMP Electrical Maintenance Precedure
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ESF Engineered Safety Feature FW Feedwater LER Licensee Event Reports MRF Modification Request Form MSly Main Steam Isolation Valve MWR Maintenance Work Request NCN Nonconformance Notice
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NRC.
Nuclear Regulatory Commission
NRR Nuclear Reactor Regulation 0N0 Off Normal Occurrence PM Preventive Maintenance
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PMTS Preventive Maintenance Task Sheet RBCU Reactor Building Cooling Units RCS.
Reactor Coolant System RCP Reactor Coolant Pump RHR Residual Heat Removal RWP Radiation Work Permits
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SCE&G South Carolina Electric & Gas
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S0P System Operating Procedures l
SPR Special Reports l
STP Surveillance Test Procedures
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l SW Service Water TS T*:chnical Specifications VCSNS V. C. Summer Nuclear Station
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VU Chilled Water j
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