ML20212J309
| ML20212J309 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 01/20/1987 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20212J288 | List: |
| References | |
| NUDOCS 8701280133 | |
| Download: ML20212J309 (5) | |
Text
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CONTAINMENT SYSTEMS REACTOR BUILDING COOLING SYSTEM LIMITING CONDITIONS FOR OPERATION 3.6.2.3 Two independent groups of reactor building cooling units shall be OPERABLE with at least one of two cooling units OPERABLE in slow speed in each group.
APPLICABILITY: MODES 1, 2, 3 and 4.
ACTION:
a.
With one group of the above required reactor building cooling units inoperable and both reactor building spray systems OPERABLE, restore the inoperable group of cooling units to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
b.
With two groups of the above required reactor building cooling units inoperable, and both reactor building spray systems OPERABLE, restore at least one group of cooling units to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
Restore both above required groups of cooling units to OPERABLE status within 7 days of initial loss or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
c.
With one group of the above required reactor building cooling units inoperable and one reactor building spray system inoperable, restore the inoperable spray system to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN I
within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
Restore the inoperable group of containment cooling units to OPERABLE status within 7 days of initial loss or be in at least HOT STANOBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
SURVEILLANCE REQUIREMENTS 4.6.2.3 Each group of reactor building cooling units shall be demonstrated OPERABLE:
i a.
At least once per 31 days by:
1.
Starting each cooling unit group from the control room, and verifying that each cooling unit group operates for at least 15 minutes in the slow speed mode.
b.
At least once per 18 months by:
1 1.
Verifying that each fan group starts automatically on a safety injection test signal.
2.
Verifying a cooling water flow rate of greater than or equal to i
E ooo-4 0007Jpm to each cnoling unit group.
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7 Sut9tER - UNIT 1 3/4 6-14 8701280133 870120 PDR ADOCK 05000395 P
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._m Attachment I to H. R. Denton letter y
AttacrM nt 'to [k. Je6tonj'46e[,
January 20, 1987 7
Dece:1er 2,
- 36
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Page 3 of 4 2aje5of6' CONTAINMENT SYSTEMS BASES 3/4.6.2.2 SPRAY ADDITIVE SYSTEM The OPERASILITY of the spray additive system ensures that sufficient NaOH is added to the reactor building spray in the event of a LOCA. The limits on NaOH volume and concentration ensure a pH value of between 8.5 and 11.0 for the solution recirculated within containment after a LOCA. This pH band minimizes the evolution of iodine and minimizes the effect of chloride and caustic stress corrcsion on mechanical systems and components. The contained solution volume limit includes an allowance for solution not usable because of tank discharge line location or ether physical characteristics. These assump-tions are consistent with the iodine removal efficiency assumen in the accident analyses.
3/4.6.2.3 REACTOR BUILDING COOLING SYSTEM The OPERABILITY of the reactor building cooling system ensures that i
- 1) the reactor building air temperature will be maintained within limits during normal operation, and 2) adequate heat removal capacity is available when operated in conjunction with the reactor building spray systems during i
post-LOCA conditions.
The reactor building cooling system and the reactor building spray system are redundant to each other in providing post accident cooling of the react,or building atmosphere. As a result of this redundancy in cooling capability, the allowable out of service time requirements for the reactor building cooling system have been appropriately adjusted. However, the allowable out of service time requirements for the reactor building spray system have been maintained consistent with that assigned other inoperable ESF equipment since the reactor building spray system also provides a mechanism for removing iodine from the reactor building atmosphere.
saserr z HEM 3/4.6.3 PARTICULATE IODINE CLEANUP SYST The OPERABILITY of the containment filter trains ensures that sufficient iodine removal capability will be available in the event of a LOCA. The reduction in containment iodine inventory reduces the resulting site boundary radiation doses associated with containment leakage. The operation of this system and resultant iodine removal capacity are consistent with the assumptions used in the LOCA analyses.
SUptlER - UNIT 1 8 3/4 6-4
Attachment I to H. R. Denton letter January 20, 1987 Page 4 of 4 R.[nJd)etM Att tp(nt t
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gac( SeNCS The accident analysis requires the service water booster pump to be passing 2, ooo +<000 gpm to a RBCU % within 86.5 seconds. This time encompasses the driving of all necessary service water valves to the correct positions, i.e.,
fully opened or fully closed. Reference. Technical Specification Bases 83/4.3.1 and B3/4.3.2 for additional details.
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Attachment II Page 1 of 2 BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION The existing RBCU service water outlet valves, XVG-3109A,B,C and 0-SW, are non-active and therefore cannot be assumed to be capable of operation post accident. Since Service Water (S.W.) flow presently passes through the operating and non-operating RBCU's, the Technical Specification flow is 200%
of the flow required for cooling. MRF-21022 converts the RBCU service water outlet valves to active motor operated valves with automatic controls to open the valves on the RBCU selected post accident, and close the valves on the non-selected RBCU.
Specification 4.6.2.3 requires that the service water booster pump flow be at least 4,000 GPM to assure that the selected RBCU in each train receives it's required 2,000 GPM. Since only 2,000 GPM is required per selected RBCU and the system is designed to have only one RBCU and it's associated fan in each train in service for the DBA, the required flow through the service water booster pump can be reduced to 2,000 GPM.
This proposed amendment has been reviewed and determined not to involve a significant hazards consideration for the following reasons:
1.
a)
An increase in the probability of the previously evaluated occurrences in the FSAR/FPER will not occur. The valves are being made active to facilitate the removal of heat from the containment following a condition IV event by assuring that the entire S.W.
flow provided for containment cooling is delivered to the active (fans running) reactor building coolers.
b)
There will be no increase in the consequences of an accident previously evaluated in the FSAR/FPER. Since this modification will increase the S.W. flow margin it will enhance the capability to remove reactor building heat following a Condition IV event and assures that any potential release of radioactivity will be less than the FSAR licensing basis.
c)
The upgrade of these valves to active status will not adversely affect the functions of equipment important to safety as previously evaluated in the FSAR/FPER. Separation of redundant electrical systems is maintained per FSAR section 8.3.1.4.1, and Electrical l
Construction Guidelines Dwg. S-200-926, sheet 6, revision 3, paragraph 2.3.6; sheet 4, revision 5, paragraph 2.1.8. This separation is maintained by physical distance, and the installation of a single Kaowool wrap, acting as a suitable barrier.
Installed conduit is designed to withstand a seismic event, and to avoid main steam line break ' jet-cones'. The modified valve operators are seismically designed, and valve position status lights on the ESF equipment board are designed as described in the FSAR.
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Attachment II Paga 2 of 2 e
d)
The use of active valves in these positions does not increase the consequences of a malfunction of equipment important to safety as previously evaluated in the FSAR/FPER. Any malfunction of these valves as the single active failure results in the same consequences from the accident. All accidents evaluated in the FSAR/FPER bound any accidents which these valves may create or contribute to.
2.
No malfunctions of equipment important to safety are anticipated which will be different from those malfunctions already evaluated in the FSAR/FPER. The modification will not induce water hammer transient loadings in the piping system. Flow limiting orifices in the discharge pipe are revised to maintain the S.W. system pressure in the reactor building and to prevent excessive flow thru the R.B. cooling coils. The reduced flow thru the S.W. booster pump after the modification is greater than the minimum flows the pump was tested at. The valve operator stroke time maintains the margin of safety as defined in Tech. Spec. Table 3.3-5 for service water response times.
3.
The margin of safety as defined in the bases to Tech. Spec. 3/4.6.2.3 is not reduced by this modification. This modification will permit a reduction in the surveillance requirements for S.W. flow. The Tech.
Spec. surveillance flow of 4,000 GPM is the total of:
1) 2,000 GPM to the active functioning R.B. Fan Cooler, and 2) 2,000 GPM to the non-functioning fan cooler. This modification will allow the isolation of flow to the non functioning R.B. Fan Cooler. This will permit a reduction in the surveillance flow requirements to 2,000 GPM. This modification will increase the margin of flow to the R.B. Fan Cooler operating post accident above the 2,000 GPM required and will provide cooling capacity greater than that assumed for accident analysis.
This modification does not affect the reactor building cooling during normal plant operation.
Based on the above considerations, SCE&G has determined that this change does not involve a significant hazards consideration.
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