ML20206T214
| ML20206T214 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 05/17/1999 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20206T212 | List: |
| References | |
| NUDOCS 9905240091 | |
| Download: ML20206T214 (8) | |
Text
r PLANT SYSTEMS CONDENSATE STORAGE TANK LIMITING COMITION FOR OPERATION
- 3. 7.1. 3 volume of at least 172,7% pallons of water.The condensate storage tank (C A 1
- t~19, E s o APPLICA8ILITY: MODES 1, 2 and 3.
ACTION:
With the condensate storage tank inoperable,.within.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> either:
Restore the CST to OPERABLE status or be in at least HOT STAND 8 a.
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 HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, or b.
Demonstrate the OPERABILITY of the service water system as a backup supply to the emergency feedwater pumps and restore the condensate storage tank to OPERABLE status within 7 days or be in at least HOT STAN08Y 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 HDT SHUTDOWN within the
.following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
j SURVEILLANCE REQUIREMENTS 4.7.1.3.1 The condensate storage tank shall be demonstrated OPERABLE at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying the contained water volume is within its limits when the tank is the supply source for the emergency feedwater pumps.
4.7.1.3.2 The service water system shall be demonstrated OPERABLE at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying service water systen pressure whenever the service water system is the supply source for the emergency feedwater pumps.
h DO O
5 P
SUPO4ER - UNIT 1 3/4 7-6 i
PLANT SYSTEMS CONDENSATE STORAGE TANK LIMITING CONDITION FOR OPF. RATION 3.7.1.3 The condensate storage tank (CST) shall be OPERABLE with a contained volume of at least 179,850 gallons of water.
l APPLICABILITY: MODES 1,2, and 3.
ACTION:
With the condensate storage tank inoperable, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> either:
a.
Restore the CST to OPERABLE status 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 HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, or b.
Demonstrate the OPERABILITY of the service water system as a backup supply to the emergency feedwater pumps and restore the condensate storage tank to OPERABLE status within 7 days or be in at least HOT STANDBY within the next i
6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.7.1.3.1 The condensate storage tank shall be demonstrated OPERABLE at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying the contained water volume is within its limits when the tank is the supply source for the emergency feedwater pumps.
4.7.1.3.2 The service water system shall be demonstrated OPERABLE at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying service water system pressure whenever the service water system is the supply source for the emergency feedwater pumps.
l i
i SUMMER - UNIT 1 3/4 7-6 Amendment No.
I
Docum:nt Control D:sk Attachment il TSP 980003 RC-99-0100 i
Page 1 of 3 SAFETY EVALUATION REVISION OF MINIMUM CONTAINED VOLUME OF THE CONDENSATE STORAGE TANK FOR THE VIRGIL C. SUMMER NUCLEAR STATION TECHNICAL SPECIFICATIONS Description of Amendment Request SCE&G proposes to change the volume of water required to be contained in the 1
Condensate Storage Tank (CST), as specified by LCO 3.7,1.3, from 172,700 gallons to 179,850 gallons. This change is based on the increased requirements created by i
uprating the plant and installing replacement steam generators and also reflects s recalculated value of the unusable volume of the CST.
j A minimum volume of water in the Condensate Storage Tank is specified to ensure sufficient water is available to the Emergency Feedwater (EFW) System to maintain the I
RCS at HOT STANDBY for eleven hours with steam discharge to the atmosphere i
concurrent with total loss of offsite power. The contained water volume limit includes an allowance for water that is not usable by the Emergency Feedwater System because of the location of the tank discharge line or other physical characteristics (References 1,2).
The volume of water currently required by LCO 3.7.1.3 to be contained in the CST is 172,700 gallons. This includes 155,000 gallons which is dedicated to the EFW System (Reference 3).
The CST inventory required to maintain HOT STANDBY for an 11 hour1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> period has been increased from 155,000 to 158,570 gallons to account for uprated plant conditions with the replacement steam generators (Reference 2). The maximum CST inventory that is available to the EFW System, based on nozzle locations is 160,054 gallons, while the volume of water in the CST that is unusable to the EFW System is 19,794 gallons (Reference 4).
This proposed change to the Technical Specifications changes the required volume of water in the CST to 179,850 gallons (160,054 gallons available plus 19,794 gallons unusable, rounded up to 179,850 gallons). This is a conservative summation of the maximum volume available to the EFW System (which is greater than the required i
inventory) and the volume that is unusable to the EFW System.
Document Conttol D sk
. Attachment il TSP 980003
~
, RC-99-0100 Page 2 of 3-References
- 1. VC Summer Technical Specification Bases 3/4.7.1.3, " Condensate Storage Tank"
- 2. Westinghouse Report WCAP 13714, "RSG/Uprate Engineering Report", Section 4.6.3.5, " Condensate Storage Tank Volume Requirements" 3.' Westinghouse letter CGWG-345, March 7,1973,." Pump Capacities and Assured Storage Quantity"-
- 4. SCE&G Calculation DC05220-048, Revision 2, " Determination of Minimum Required Volume in Condensate Storage Tank for Emergency Feedwater" Safety Evaluation The minimum volume of water required to be contained in the CST, as specified by LCO 3.7.1.3, is being changed from 172,700 gallons to 179,850 gallons. This change is based on the increased requirements created by uprating the plant and installing replacement steam generators and also reflects a recalculated value of the unusable volume of the CST.
The previous required inventory of 155,000 gallons was originally based on a very conservative analysis of the CST inventory needed to maintain HOT STANDBY for two hours followed by a four hour cooldown period to 350 F (very conservative values were used for steam generator low-low level and refill volume). Later, this analysis was revised to include an evaluation of maintaining HOT STANDBY for eleven hours and it was determined that the 155,000 gallon inventory was' acceptable for both cases.
The analysis performed for plant uprate with replacement steam generators considered both cases and determined that 152,550 gallons were required to maintain two hours at HOT STANDBY followed by a four hour cooldown period to 350 F; and 158,570 gallons are required to maintain HOT STANDBY for an eleven hour period.' Specifying
.the new required CST contained volume based on the analysis for maintaining HOT STANDBY for eleven hours bounds the previous two hour requirement.
The analysis performed for plant uprate with replacement steam generators uses the same methodology as'the original analysis.' The analysis calcul tes required condensate volumes in two parts. The first part of the analysis calculates the required condensate storage to maintain the plant at HOT STANDBY for a selected time period
- and to refill the steam generators to normal levels. The second part 'of the analysis calculates the condensate storage required to cool down to HOT SHUTDOWN conditions at 350 F over a selected time period so the RHR system can be aligned for operation, u
Docum:nt Control D:sk Attachment ll TSP 980003
, RC-99-0100 Page 3 of 3 The calculation takes into account several general assumptions (consistent with the original analysis assumptions) as follows:
- 1. Reactor trip occurs from 102% of Engineered Safeguards Design Rating, from a low-low water level in all steam generators.
- 2. Steam generator blowdown is automatically terminated when the EFW pumps start.
- 3. Steam is initially released from the steam generators at 103% of the first safety valve pressure setting.
- 4. The reactor coolant pumps are not operating.
- 5. All steam generators are refilled to normallevel.
This change does not reduce any margin associated with the CST inventory available to the EFW. In fact, a small gain in margin (less than 1%) is realized by specifying the minimum required volume based on the maximum volume available due to nozzle locations and other physical characteristics of the tank instead of the minimum required to maintain HOT STANDBY for 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br />. Additionally, the requirement for sufficient I
CST volume to maintain HOT STANDBY for 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> is still met and the Service Water System still provides the long term supply of safety grade cooling water to the EFW System. The Service Water supply is not affected by this change, and thus the margin for safety grade cooling water to the EFW System (or safety grade cooling of the RCS) is not affected.
i i
L
a
~
Documnrd Control Dssk Attachment lll TSP 980003 RC-99-0100
' Page 1 of 3 NO SIGNIFICANT HAZARDS EVALUATION FOR REVISION OF MINIMUM CONTAINED VOLUME OF THE CONDENSATE STORAGE TANK IN THE VIRGIL C. SUMMER NUCLEAR STATION TECHNICAL SPECIFICATIONS Description of Amendment Reauest SCE&G proposes to change the volume of water required to be contained in the Condensate Storage Tank (CST), as specified by LCO 3.7.1.3, from 172,700 gallons to 179,850 gallons. This change is required based on the increased requirements created by uprating the plant, and installing replacement steam generators.
A minimum volume of water in the Condensate Storage Tank is specified to ensure sufficient water is available to the Emergency Feedwater (EFW) System to maintain the RCS at HOT STANDBY for eleven hours with steam discharge to the atmosphere concurrent with total loss of offsite power. The contained water volume limit includes an allowance for water that is not usable by the Emergency Feedwater System because of the location of the tank discharge line or other physical characteristics (References 1,2).
J The volume of water currently required by LCO 3.7.1.3 to be contained in the CST is 172,700 gallons. This includes 155,000 gallons which is dedicated to the EFW System (Reference 3).
The CST inventory required to maintain HOT STANDBY for an eleven hour period has been increased from 155,000 to 158,570 gallons to account for uprated plant conditions with the replacement steam generators (Reference 2). The maximum CST inventory that is available to the EFW System, based on nozzle locations, is 160,054 gallons, while the volume of water in the CST that is unusable to the EFW System is 19,'794 gallons (Reference 4).
This proposed change to the Technical Specifications changes the required volume of water in the CST to 179,850 gallons (160,054 gallons available plus 19,794 gallons unusable, rounded up to 179,850 gallons). This is a conservative summation of the maximum volume availab!e to the EFW System (which is greater than the required inventory) and the volume that is unusable to the EFW System.
L
Docum:nt Control D:sk
' 11 TSP 980003 RC-99-0100 l
Page 2 of 3 References
- 1. V. C. Summer Technical Specification Bases 3/4.7.1.3, " Condensate Storage Tank"
- 2. Westinghouse Report WCAP 13714 "RSG/Uprate Engineering Report" Section 4.6.3.5 " Condensate Storage Tank Volume Requirements"
- 3. Westinghouse letter CGWG-345, March 7,1973, " Pump Capacities and Assured Storage Quantity"
- 4. SCE&G Calculation DC05220-048, Revision 2," Determination of Minimum Required Volume in Condensate Storage Tank for Emergency Feedwater" i
Basis for No Sionificant Hazards Consideration Determination in accordance with 10CFR50.92, a proposed change to the operating 1.icense involves no "significant hazards"if' operation of the facility, in accordance with the proposed change, would not:
- 1) involve a significant increase in the probability or consequences of any accident previously evaluated;
- 2) create the possibility of a new or different kind of accident from previously evaluated, or;
- 3) involve a significant reduction in a margin to safety.
This request is evaluated against each of these criteria as follows:
1.
This request does not involve a significant increase in the probability or consequences of an accident previously evaluated.
FSAR 10.4.9.1 states that minimum required usable volume for the Condensate Storage Tank (CST) is 158,570 gallons based on maintaining the plant at HOT STANDBY conditions for eleven hours. This volume has already been adjusted for both plant uprate conditions and replacement steam generator requirements. This change to LCO 3.7.1.3 will ensure that 160,054 gallons is maintained in the CST, being available and dedicated to the Emergency Feedwater (EFW) System. Thus, this change will ensure that the EFW System has an adequate water supply to perform its design basis function in regard to maintaining the plant in HOT STANDBY condition.
2.
This request does not create the possibility of a new or different kind of accident from any accident previously evaluated.
m
r Document Control D:sk Attachment lll TSP 980003
, RC-99-0100 Page 3 of 3 1
i This change increases the minimum required volume of water in the CST, thus ensuring that the EFW System can perform its required safety function. The maximum and normal water levels in the CST are not i
being changed. ' Therefore, no new failure modes of the CST, or flooding concerns are created.
f 3.
This request does not involve a significant reduction in a margin to safety This change does not reduce any margin associated with the CST inventory available to the EFW. In fact, a small gain in margin (less than 1%) is realized by specifying the minimum required volume based on the maximum volume available due to nozzle locations and other physical characteristics of the tank instead of the minimum required to maintain i
l HOT STANDBY for 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br />. Additionally, the requirement for sufficient CST volume to maintain HOT STANDBY for 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> is still met and the Service Water System still provides the long term supply of safety grade cooling water to the EFW System. The Service Water supply is not affected by this change, and thus the margin for safety grade cooling water to the EFW System (or safety grade cooling of the RCS) is not affected.
Environmental Impact Consideration
' SCE&G has reviewed this request against the criteria of 10CFR51.22 for environmental I
considerations. Since this request involves (i) no significant hazard consideration, (ii) no significant change in the types or significant increase in the amounts of any effluents that may be released offsite, and (iii) no significant increase in individual or cumulative occupational radiation exposure, SCE&G has concluded that the proposed change meets the criteria given in 10CFR51.22 (c)(9) for a categorical exclusion from the requirement for an environmental impact statement.
l l
l E