ML20247D259
| ML20247D259 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 08/06/1988 |
| From: | Bradham O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8905250296 | |
| Download: ML20247D259 (10) | |
Text
j , ;,i .10CFR50.59
"'Q*'
~
, gth, Carolina Electric & Gas Company Ollie . dham
... e insv le SC 29065 Nuclear Operations SCE&G 4 * * * " " * .May 10, 1989 89 MAY 17 A 9: 05 f
Mr. S. D. Ebneter
. Regional Administrator U. S. Nuclear Regulatory Commission Region II, Siiite 2900 101 Marietta Street, N.W.
Atlanta, Georgia 30323
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12
< Annual 10CFR50.59 Report
Dear Mr.-Ebneter:
Attached is the sixth Annual Report provided pursuant to 10CFR50.59(b) for
.the Virgil C. Summer Nuclear Station. This report includes a brief description of modifications made to the facility as described in the Final Safety Analysis Report (FSAR) and a summary of the safety evaluation of each.
These modifications, identified by the Modification Request Form (MRF) number where applicable, were completed prior to August 6, 1988, which ended the sixth year following the issuance of the Facility Operating License.
If you have any questions, please advise.
Very truly yours, M
- 0. S. Bradham e
HID/OSB: led Attachment c: D. A. Nauman/0. W. Dixon, Jr./T. C. Nichols, Jr.
E. C. Roberts W. A. Williams, Jr. G. O. Percival General Managers R. L. Prevatte C. A. Price /R. M. Campbell, Jr. J. B. Knotts, Jr.
R. B. Clary NSRC J. R. Proper NPCF -
J. C. Snelson File (818.02-8)
_ _ _ - _ _ W-
Attachment I to Mr. 3. D. Ebneter Letter
.May 10,'1989 Page 1 of 10 SIXTH ANNUAL 10CFR50.59 REPORT VIRGIL C. StMIER NUCLEAR STATION MRF-10038 This modification added a nitrogen connection to the Waste Evaporator Vent Condenser to allow pressurization with nitrogen for pumpdown before waste evaporator shutdown. The connection to the nitrogen header is classified as non-nuclear safety related (NNS) and at the waste evaporator vent condenner inlet valve as quality related in accordance with I
Regulatory Guide 1.143. The margin 'of safety has not been reduced since the nitrogen header is NNS and the waste evaporator is protected from overpressurization by a rupture disk.
This modification also revised the interim essential drawings for the waste evaporator upgrade modification and evaluated the leakage rate from two safety related instrument root valves which are the code boundary break points in a component cooling water flow sensor. The flow sensor is used to measure flowrate through a heat exchanger added by this modification.
This change . does not create an unreviewed safety question since it is in the non-essential loop of the component cooling water system and any potential leakage will not exceed the margin of allowed design leakage for the component cooling water system. The margin of safety was not reduced.
MRF-10393 This modification provided a ball valve to replace a gate valve in the fire service system. This valve change reduces the possibility of leakage when the valve is cycled and tested,. therefore, maintaining the system design basis.
Because the valve is an equal to or better than replacement the system integrity has not been altered. The margin of safety has not been reduced by this modification as the change increases the performance of the fire service system.
MRF-10739 This modification installed two prusure indicators and a sample flowmeter on the Post Accident Sampling System (PASS) in order to measure system vacuum flow to verify adequate purging and flushing rates are being achieved. The equipment installation improved system reliability. The margin of safety was not reduced.
MRF-20346 This modification provided an additional 25 feet of fire hose to hose station XVG-6764. The additional length of hose was required to provide better hose station coverage on elevation 388' of the Auxiliary Building. This modification increases the level of fire protection in the area. The probability of an occurrence or consequences of an accident or malfunction of SR equipment as previously evaluated is not increased nor is the possibility of an accident or malfunction of different type created. The margin of safety was improved.
.. . 3
. . I Attachment I to Mr. S. D. Ebneter Letter 1
-. May 10, 1989 Page 2 of 10 MRF-20384 This modification performed several minor changes including:
relocation of check valve 4071-FS from upstream to downstream of the fire service jockey pump, XPP 133 and the resetting of pressure switch IPS-4907 and relief valve XVR-6946-FS. The reason for -this modification was to achieve a more standardized arrangement in accordance with the Fire
' Protection Handbook and to document the as-built configuration of the fire service jockey pumps' function in relation to the entire fire service system. The margin of safety was not reduced.
MRF-20492 This modification provided as-built drawings of the Security Building addition outside the Protected Area. This building was added as an office facility and access portal for the Protected Area. The security aspects were handled in accordance with existing guidelines and provides for the proper , barriers and precautions per the security plan. The margin of safety was not reduced.
MRF-20548 This modification replaced the current high range containment monitor with a Victoreen model 875 High Ranger containment monitor. The new monitor is a fully qualified separate unit which can be calibrated and maintained more easily. The previous unit was contained inside a penetration and was difficult to calibrate. The margin of safety was not decreased.
MRF-20551 These modifications installed isolation valves in the relief and valve discharge piping from the waste gas hydrogen recombiners and waste gas compressors. The valves are closed during MRF-20552 maintenance to prevent the backflow of waste gas from the relief header and decay tank. The margin of safety has not been affected because the valves are administrative 1y locked open during system operation and the consequences of a potential malfunction are much less severe than the accident analyzed in the FSAR 15.3.5.
MRF-20554 This modification added controls to XVD-1920-B to increase its opening time, causing XVD-1920-B to act like an orifice, to prevent downstream water / pressure spikes and to relieve pressure spikes and reduce maintenance on the system valves downstream from XVD-1920-B.
The safety function of XVD-1920-B is to fail closed. This modification does not alter the valve's safety function and therefore does not create any new accidents, increase the possibility of an accident or decrease plant safety; therefore, the margin of safety was not reduced.
MRF-20614 This modification added the exhaust flow of the new Radiological Maintenance Building to the existing main plant vent. This exhaust flow is necessary to ensure that adequate ventilation is provided in appropriate areas of this new
t
Attachment I to Mr. S. D. Ebneter Letter I
May 10, 1989 Page 3 of 10 building. This modification has been evaluated to be within the plant's design basis for ventilation design. The margin of safety was not reduced.
MRF-20713 This modification removes 4 of the 16 springs in the Main Steam (MS) Power Operated Relief Valves (PORV's). This change allows full stroking of the valves (i.e., from tight shut-off to. full stroke) with the available instrument air pressure.
These pilot springs ensure the pilot plug opens first by.
counteracting the actuator spring. If the pilot spring force is too great the actuator spring loading must be increased to counteract this force. The valve is opened by air pressure-counteracting the actuator spring force. Therefore, for proper valve stroking with the available instrument air pressure, the spring forces must be adjusted. This change allows the valves to function as they were originally specified. There is no change to the probability or consequences of an accident or malfunction. The work.
performed internal to this valve was not postulated to generate any new accident or malfunction. The work on the MS PORV's did not hinder the function of the valves; therefore, the margin of safety was not reduced.
MRF-20784 This modification provided sufficient electrical isolation to terminate spurious component operation which could occur due to postulated hot shorts caused by fire damage and two disconnect points in the main control board termination cabinets in the cable spreading room. The disconnect switches are passive devices which are manually operated to insure positive circuit opening in the event of a fire. Normal operation of the systems is not affected. The margin of safety was not reduced.
MRF-20791 This modification provided local control of the "B" water chiller, isolated Control Building cables from potential " hot shorts" and added emergency lighting to the chiller room It provided an upgraded and more reliable system for the local control of the chiller in order to shut the plant down in the event of a Control Room fire. The margin of safety was not reduced.
MRF-20792 This modification installed telephones and a GAI-TRONICS handset with speakers in the calibration lab and repair shop of the Auxiliary Building. Plant personnel in the calibration lab and repair shop had no means of communications with other plant personnel during normal or emergency condition (s).
Providing plant communications for personnel in these areas actually increased general plant safety. Therefore, the probability of an occurrence, the consequences of an accident and the probability of a malfunction of equipment important to safety was not increased and therefore the margin of safety was not reduced.
' Attachment-I to Mr. S. D. Ebneter Letter May 10, 1989 Page 4 of 10.
1 MRF-20827 This modification provided isolation fuses and separation criteria that allowed the use of a non-nuclear safety related (NNS) single cell charger on the safety related (SR) battery bank. The NNS single cell charger is used for temporarily l providing an equalizing charge in excess of 2.33 volts / cell I
for a segment of battery cells to assure required battery capacity and for battery life extension. The connection of NNS equipment to SR equipment did not reduce the margin of.
safety because of the isolation fuses and separation criteria specified.in the design.
MRF-20854 This modification installed a permanent tool box in each diesel generator area. These tool boxes are to hold large tools that are for diesel generator wxk only and in the past had taken a long time to get the tools into the area. The installation of these tool boxes considered all standard design conditions and all applicable accidents in chapter 15
" Accident Analysis". This modification did not reduce the margin of safety.
MRF-20903 This modification installed a relay to mute speakers automatically in the immediate vicinity of the control room during activation of plant' alarms. Control room personnel had difficulty conversing with the operations personnel in the plant due to the high sound level of the alarms in the control room. This modification enhanced communications between control room and operations personnel during the event of plant alarms. Therefore, general plant safety was increased W this modification. The probability of an occurrence, the consequences of an accident and the probability of a malfunction of equipmer,t important to safety was not increased and therefore the margin of safety was not reduced.
MRF-20966 This modification provided a monitoring system for underground storage tanks that detects water accumulation inside the tanks. The monitor also measures level and leakage. The system monitors the two diesel fuel oil tanks XTK-53-A&B and the turbine lube oil tanks XTK-23 (new and used oil compartments). The monitoring system (TLS-250) including the level probes and associated wiring is non nuclear safety. The turbine lube oil tank XTK-23 is non nuclear safety. The diesel fuel oil storage tanks XTK-53-A & B are safety related.
Inserted stand pipes have been installed in XTK-53-A & B in order to retain the boundary between safety and non safety equipment. The non safety level probes are inserted inside the stand pipe inserts. Malfunction of the monitors will not affect the safe operation of the plant and the margin of safety was not reduced.
MRF-20975 This modification removed the old Auxiliary Access Portal (AAP), relocated the west perimeter admin / protected barrier fence and erected the new Security Building and AAP. The control of acces<, into the Protected Area was improved through the installation of the new facility and equipment and
Attachment I to Mr.-S. D. Ebneter Letter May 10, 1989 Page 5 of 10 provided a second 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> access. It did not affect nuclear-safety related structures, systems, or equipment. The margin of safety was not reduced.
MRF-20984 This modification installed an operator watch station in the Auxiliary Building (AB) at elevation 412 as an environmentally controlled area for the AB operators._ The impact of this modification on the design basis and its affects on plant equipment were evaluated and found not to affect any nuclear safety equipment or essential equipment under existing design criteria and accident analysis. This modification did not reduce the margin of safety.
MRF-21014 This -modification relocated the temporary diesel air compressor and connected it to the Instrument Air (IA) system with permanent piping. The modification was done to provide better access to the Turbine Building railroad access bay and to make, the supply line a permanent plant fixture. This instrument air system compressor is non-safety and does not perform anf safe-shutdown function. This modification does not affect any safe-shutdown equipment so the margin of safety was not reduced.
MRF-21016 This modification added a moisture test point upstream of the Instrument Air (IA) pre-filters. This connection allows the detection of moisture on the upstream and downstream sides of the dryer. All material and equipment affected by this modification is Non Nuclear Safety (NNS). The addition of this connection did not affect the safety function of any safety related eauipment. System operation was not altered due to this modification. The margin of safety was not reduced.
MRF-21026 This modification installed a dual relief valve system on the liquid nitrogen storage tank - XTK-177-NN. The dual relief valve system piovides a three way valve which permits isolation for a leaking relief valve while providing tank over pressurization protection through the second relief valve.
None of the Nuclear Steam Supply System (NSSS) components to which the system supplies nitrogen will be affected by the failure or off . normal operation of the design change. The margin of safety was not reduced.
MRF-21045 This modification installed a 12" high raised platform adjacent to a redesigned supervisor's console. Additionally, the four 19" diagonal CRTs were replaced with high resolution non-glare 13" CRT . Additional GAI-TRONICS units and radio handsets were installed. The changes were accomplished in order to improve the supervisor's view of the Main Control Board (MCB). This had been identified as a human factors deficiency. This modification affected only non-process equipment and non-safety related computer displays. By improving the supervisor's visibility of the MCB and adding additional communications equipment, operations ability to
Attachment I to Mr. S. D. Ebneter Letter May~10. 1989 Page 6 of 10 mitigate the consequences of an accident was enhanced. The probability of an accident or failure of safety-related equipment was not increased for an analyzed or unanalyzed accident. These changes did not affect the margin of safety.
MRF-21076 This modification provided a new six (6) inch Fire Service (FS) supply line which tied into the existing twelve.(12) inch underground FS loop. The new supply line was required to provide FS water for the new Security. Building. The supply line was added for a building located outside the Protected Area and does not affect safety related equipment. A sectional isolation valve was installed in the supply line to allow it to be isolated from the FS loop if needed so as not to affect safety related equipment. The margin of safety was not reduced.
MRF-21090 This modification added partitions and open ceiling grid on the 448'. elevation of the Control Building in order to utilize a portion of the floor for an office area. This provided a professional work space for I&C supervisory personnel. The change had no impact on plant safety. The margin of safety was not reduced.
MRF-21158 This modification added catch basins and minor extensions to the existing plant storm drainage system. The changes were made to eliminate areas in the yard where water pooling tended to occur after heavy rains. The storm drain system is non-safety, non-quality related. The changes do not affect the FSAR analysis that showed no water could back up into the system and be - detrimental to plant safety. The margin of safety was not reduced.
MRF-21182 This modification added a permanent valve and 6-inch flanged connection to the Condensate System to allow for temporary processing with an oil filtration skid system as required.
Oil infiltration into the Condensate System was a temporary problem which has since been corrected. This change did not involve an unreviewed safety question because failure of the added equipment during temporary processing would not result in a loss of condensate greater than that evaluated for a loss from the main Condensate System and would not exceed building flooding design. The margin of safety was not reduced.
MRF-21234 This modification removed the low suction pressure interlock from the service water booster pumps. This interlock could prevent manual operation of the service water booster pumps for Reactor Building cooling. The removal of the non safety i related manual start interlock ensured that the operator can take action to establish reactor building cooling. The change i did not affect any automatic safety function. The margin of safety was not reduced.
L. 4~ - .
Attachment I to Mr. S. D. Ebneter Letter c May 10, 1989 Page 7 of 10-MRF-21287 This modification provided a setpoint adjustment for the correct "g" values on seismic response recorder - 1YM-1783; art also changed the setpoints for annunciator -1YA-1780 to a value of "2/3 OBE" in lieu of "1/2 SSE" which conforms - to current. industry guidelines. The setpoints were found to be too high due to a misinterpretation of the Frequency Response-Spectra curves. There was no loss of safety function or major reduction of protection provided to the public's health and' safety.
MRF-21355 This modification changed the. flow setpoints for IFS-602-A&B (RHR) mini. flow from 575 to 710 gpm for low flow and from 1250
. to 1326 gpm for ' high flow. This change was made to. account for errors which may be induced during a seismic event. The amount of cooling provided by the miniflow was increased and therefore improves the margin of safety. The reduction in system f, low was not significantly affected. The margin of safety was not reduced.
MRF-21363 This modification reconfigure the existing Remote Information Acquisition Cabinet (RIAC) units to correspond with the now
" fire only" software generated during the separation of the Security and F. ire Alarm systems. The system was not revised such that an unreviewed safety question existed. All existing fire points remain on the system in addition to the inclusion of some spare points for future use. Safety related equipment was not affected. The margin of safety defined in the Fire Detection Technical Specification was increased.
MRF-21369 This modification increased the conductor sizes associated with Class 1E 125V dc field circuits routed to de load equipment in order to reduce voltage drop and to increase the margin between the required voltage and the calculated voltage at the load equipment. The probability of a malfunction of equipment important to safety or consequences of a malfunction of equipment important to safety as identified in the FSAR/FPER was not increased, and the margin of safety as defined in the bases of any Technical Specification was not reduced.
MRF-21375 This modification provided details for removing the pipe caps which existed on penetrations 600-12 and 505-18. The pipe caps were replaced with slip-on blind flanges. The reason for the modification was to provide vendor access into the Reactor Building (RB) for cables, air' lines, etc. necessary to support steam generators maintenance services or other temporary services required during plant outages. This modification did not change the Fire Protection Evaluation Report. The j integrity of the fire barriers will be maintained by the use of blind flanges bolted at the penetration ends. The blind flanges will be installed prior to declaring the penetration operable. The possibility of a malfunction of equipment important to safety different from any already evaluated in
=a. .
1 N^~ Attachment I to Mr. S. D. Ebneter Letter f May 10,' 1989 Page 8 of 10 the FSAR/FPER was not created since equipment function was not affected by this modification. The margin of safety was not reduced.
MRF-31489 This modification replaced the relief valves on the component cooling heat exchangers witn an improved model due to the unavailability of the original model. This modification was completed 8/5/85 and had no FSAR impact. In 1988 the decision was made to revise the FSAR to include the MRF reference on the plant drawings. The margin of safety was not reduced.
MRF-31738 This modification deleted the low speed operation of the service water pumps by locking the speed changing switch in l the high speed position. The speed switches had a long history of problems, had many NCN's written against them and had been a continuing maintenance problem. All accident evaluations are based on SW running in high speed, therefore, the possibility of an accident previously evaluated was not increased. The control circuits were simplified by eliminating the need to change speeds on an accident signal.
The probability of an incident different than already evaluated was decreased. The margin of safety was not reduced.
MRF-31745 This modification added drain piping underneath each component cooling water (CCW) pump motor to drain off standing water from the base of the motor frame and eliminate this source of degradation to the insulation of the motor's windings. The margin of safety was not reduced.
MRF-32719 This modification permits an alternate reconfiguration of the Reactor vessel head vent valves as described in the Westinghouse System description for the Reactor Vessel Head Vent (RVHV) system. It provided the valve line-up to allow operations the flexibility of venting the system with an alternate flow. The RVHV valves XVT-8095-A,B & XVT-8096-A,B &
C are the same size and design; therefore, reversing their position will not affect their capability to vent the system as designed. This reconfiguration provided the same degree of protection as the previous valve line-up, therefore providing the same margin of safety as previously evaluated.
MRF-32815 This modification added an air accumulator along with check valves sized to ensure that the air supply to dampers XVB-3-A, XVB-3-B, XVB-4-A & XVB-4-B will be maintained for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a loss of the normal non-safety instrument air supply, thus ensuring positive pressurization capabilities for the Control Room. Additionally, interlocks between the !
outside air intake damper and the normal ventilation fans were removed to increase the operational reliability of the system to perform its cooling functions. It also ensures the cooling function for all modes of plant operation and control room pressurization, and cleanup for LOCA releases to limit operator exposure, and upgrades the air supply to safety
. i .*
M. Attachment I to Mr. S. D. Ebneter Letter
. May 10, 1989 Page 9 of 10 related, seismic, and class III for these dampers. The margin of safety was not reduced.
FSAR Revision The FSAR was upgraded to include approved technical l Notice 629 specification increases in the allowable range of baron concentrations in the Reactor Water Storage Tank (RWST) and Emergency Core Cooling System (ECCS) accumulators. The changes assure that the reactor will remain subcritical.in the cold condition following a large break LOCA,. assuming complete mixing of the RWST, Reactor Coolant System (RCS). ECCS water and other water sources that may reside in the sump post-LOCA with all control rods assumed to be out. The post LOCA shutdown requirements are met without compromising safety.
The margin of safety was not reduced.
FSAR Revision This is a.FSAR documentation change to incorporate the results Notice 637 of large break LOCA analysis supporting plant operation with up to 16% steam generator tube plugging. The analysis was performed by Westinghouse using an approved evabation model.
This FSAR change formally incorporates into Chapter 15 of the FSAR the analysis results which were reviewed by the USNRC for issuance of Amendment No. 66 to Facility Operating License No.
NPF-12. The margin of safety was not decreased.
FSAR Revision The FSAR was revised to allow alignment of one 115KV Notice 658 transformer to one ESF bus instead of requiring parallel transformers which are only needed for powering two buses from the 115 KV system. The margin of safety of the plant was not affected since there are still two redundant offsite sources available and operating voltage ranges were unchanged.
FSAR Revision The FSAR was revised to reflect the reanalysis of the main Notice 672 feedwater line rupture concerning slow moving feedwater' check valves to confirm the FSAR conclusion. The FSAR assumed that the check valves closed instantaneously. The actual check valve design closure was 2.5 seconds. The new analysis was.
run for 5 second check valve closure to evaluate reduced mass in the steam generator and its effect on primary to secondary heat transfer. The reanalysis resulted in adequate decay heat removal, prevention of overpressurization of the RCS or uncovering of the core. Therefore, the conclusion presented in the FSAR remained valid; the margin of safety was not reduced.
_ _ _ - _ _ - _ _ _ - - _ _ _ _ _ _ _ - -