ML20155J182
| ML20155J182 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 11/04/1998 |
| From: | NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO) |
| To: | |
| Shared Package | |
| ML20155J139 | List: |
| References | |
| NUDOCS 9811120052 | |
| Download: ML20155J182 (12) | |
Text
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' EMFRGENCY CORF COOLING SYSTFMS l
- Eten tulKYSTFMS - T. l GRFATER THAN OR EDUAL TO 3S0*F
,c I SIMVElllANCF REQUIREMFNTS 1
j 4.5.2 Each ECCS subsystem shall be demonstrated OPERABLE:
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At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying that the following valves are in I the indicated positions with power to the valve operators removed:
MAl ve Number Valve Function !
Valve Position !
SI-V-3 Acetaulator Isolation Open*
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- SI-V-17. Accumuistor. Isolation.
'SI-V-32 Open*' -
Accumulator Isolation Open*
SI-V-47 Accumulator Isolation Open*
SI-V-114 SI Pinp to Cold-Leg Isolation Open RH-V-14 RHR Pump to Cold-Leg Isolation RH-V-26 Open RHR Pump to Cold-Leg Isolation Open RH V-32 RHR to Hot-Leg Isolation RH-V-70 Closed RHR to Hot Leg Isolation Closed SI-V-77 SI to Hot-Leg Isolation SI-V-102 Closed SI to Hot-Leg Isolation Closed
- b. At least once per 31 days by:
! 1)
Verifying that the ECCS piping is full of water,
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p]and
- 2) i Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed. or otherwise secured l in position, is in its correct position. '
c.
By a visual inspection which verifies that no loose debris (rags, trash, clothing, etc.) is present in the containment which could be transported to the containment stnp and cause restriction of the purrp suctions during !
LOCA conditions. This visual inspection shall be performed:
1)
_ For all accessible areas of the containment prior to establishing primary CONTAINMENT INTEGRITY, and 2)
At least once daily of the areas affected within containment by containment entry and during the final entry when primary CONTAIM1FNT INTEGRITY is established. ,
M.
- pressurizer pressure above 1000 psig.
SEABROOK - UNIT 1 3/4 5-5 9811120052 981104 ~"
Amendment No. -39)
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! l EMERGENCY CORE COOLING SYSTEMS j BASES. -
3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS (Continued)
When the RCS has a vent area equal to or greater than 18 square inches, one Safety Injection pump may be made OPERA 8LE when in MODE 5 or MODE 6 (below ' ,
- 200'F). When operating in this configuration, cold overpressure protection is j provided inches by the mechanical vent opening, equal to or greater than 18 square '
i SI pump, OPERABLE. that is required to be present in the RCS boundary prior to making the This required RCS vent area and the surveillance requirement ;
to verify the presence of the RCS vent area provides assurance that a mass f addition transient can be relieved and that adequate cold overpressure i protection is provided. ;
gp The Surveillance Requirements provided to ensure PERABILITY of each com-
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i ponent ensures that at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERASILITY is maintained. Surveillance Requirements j for throttle valve position stops and flow balance testing provide assurance that proper ECCS flows will be maintained in the event of a LOCA. Maintenance of proper tion point flow is necessaryresistanceto: and pressure drop in the piping system to each injec-(1) prevent total pump flow from exceedin conditions when the system is in its minimum resistance configuration,g runout (2) pro-vide the proper flow split between injection points in accordance with the
- assumptions used in the ECCS-LOCA analyses, and (3) provide an acceptable level of total ECCS flow to all injection points equal to or above that assumed in the
- ECCS-LOCA analyses. -
3/4.5.4 REFUELING WATER STORAGE TANK The OPERASILITY of the refueling water storage tank (RWST) as part of the ECCS ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA. The limits on RWST minimum volume and boron concentration ensure that: (1) sufficient water is available within containment to permit recirculation cooling flow to the core and (2) the reactor will remain subcritical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the cost reactive control assembly. These assumptions are consistent with the LOCA analyses.
The contained water volume limit includes an allowance for water not usable because of tank discharge line location or other physical characteristics.
The limits on contained water volume and boron concentration of the RWST also 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 andsystems mechanical minimizes the effect of chloride and caustic stress corrosion on and components.
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SEABROOK - UNIT 1 -
B 3/4 5-2 AmendmentNo.J!
, e INSERT '
O With the exception of the operating centrifugal charging pump, the ECCS pumps are normally in a standby, non-operating mode. As such, flow path piping has the potential to develop voids and pockets of entrained gases. Maintaining the piping from the ECCS pumps to the RCS full of water (by verifying at the accessible ECCS discharge piping high points and pump casings, excluding the operating centrifugal charging pump) ensures that the system will perform properly, injecting its full capacity into the RCS upon demand. This will also prevent water hammer, pump cavitation, and pumping of non- ,
condensable gas (e.g., air, nitrogen, or hydrogen) into the reactor vessel following a safety injection (SI) signal or during shutdown cooling. The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation.
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SECTION III j i
Retype Of The Proposed Change The attached retype reflects the currently issued version of the Technical Specifications. Pending Teclinic'al Specification changes or Technical Specification changes issued subsequent to this submittal are not reflected in the. enclosed retype. The enclosed retype should be checked for continuity with Technical Specifications prior to issuance.
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EMERGENCY CORE COOLING SYSTEMS ECCS SUBSYSTEMS - T x GREATER THAN OR EOUAL TO 350 F SURVEILLANCE REOUIREMENTS 4.5.2 Each ECCS-subsystem shall be demonstrated OPERABLE:
- a. At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying that the following valves are in the indicated positions with power to the valve operators removed:
Valve Number Valve Function Valve Position SI-V-3 Accumulator Isolation Open*
SI-V-17 Accumulator Is01ation Open*
SI-V-32 Accumulator Isolation Open*
SI-V-47 Accumulator Isolation Open*
SI-V-114 SI Pump to Cold-Leg i;olation Open RH-V-14 RHR Pump to Cold-Leg ' solation Open RH-V-26 RHR Pump to Cold-Leg Isolation Open RH-V-32 RHR to Hot-Leg Isolation Closed RH-V-70 RHR to Hot-Leg Isolation Closed SI-V-77 SI to Hot-Leg Isolation Closed SI-V-102 SI to Hot-Leg Isolation Closed l b. At least once per 31 days by:
- 1) Vt. ing that the ECCS piping is full of water, and l
- 2) Verifying that each valve (manual. power-operated, or l automatic) in the flow path that is not locked, sealed, or j otherwise secured in position, is in its correct position.
- c. By a visual inspection which verifies that no loose debris (rags, trash, clothing, etc.) is present in the containment which could be transported to the containment sump and cause restriction of the Jump suctions during LOCA conditions. This visual inspection shall 3e performed:
- 1) For all accessible areas of the containment prior to establishing primary CONTAINMENT INTEGRITY, and
- 2) At least once daily of the areas affected within containment by containment er.try and during the final entry when primary CONTAINMENT INTEGRITY is established.
- Pressurizer pressure above 1000 psig.
. SEABROOK - UNIT 1 3/4 5-5 Amendment No. 39,68
EMERGENCY CORE COOLING SYSTEMS l BASES l
'3/4.5.2 and 3/4.5.3 ECCS SUB5 aTEMS (Continued)
-When the RCS has a vent area equal to or greater than 18 square inches, one Safety Injection pump may be made OPERABLE when in MODE 5 or MODE 6 (below 200 F). When operating in this configuration. cold overpressure protection is provided by the mechanical vent opening, equal to or greater than 18 square i inches, that is required to be present in the RCS boundary prior to making the
~SI pump OPERABLE. This required RCS vent area and the surveillance requirement to verify the presence of the RCS vent area provides assurance that a mass addition transient can be relieved and that adequate cold overpressure protection is provided.
The Surveillance Requirements provided to ensure OPERABILITY of each com-ponent ensures that at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is maintained. With the exception of
-the o)erating centrifugal charging ) ump. the ECCS pumps are normally in a ,
stand)y. non-operating mode. As sucl. flow path piping has the potential to '
develop voids and pockets of entrained gases. Maintaining the piaing from the ECCS pumps to the RCS full of water (by verifying at the accessiale ECCS discharge piping high points and pum) casings, excluding the operating centrifugal charging pump) ensures tlat the system will perform properly.
, -injecting its full capacity into the RCS upon demand. This will also prevent water hammer, pump cavitation, and pumping of non-condensable gas (e.g., air.
nitrogen, or hydrogen) into the reactor vessel following a safety injection
.(SI) signal _or during shutdown cooling. The 31 day Frequency takes into 1 g consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation. Surveillance Requirements for throttle valve position stops and flow balance testing 3rovide assurance that proper ECCS flows will be maintained in the event.of a _0CA. Maintenance of proper flow resistance and pressure drop in the piping system to each injection )
point is necessary to: . (1) prevent total pump flow from exceeding runout I conditions when the system is in its minimum resistance configuration. (2) pro- l vide the proper flow split between injection points in accordance with the I
, assumptions used in the ECCS-LOCA analyses, and (3) provide an acceptable level i -of total ECCS flow to all injection points equal to or above that assumed in l the ECCS-LOCA analyses.
3/4.5.4 REFUELING WATER STORAGE TANK The OPERABILITY of the refueling water storage tank (RWST) as part of the f ECCS ensures that a sufficient supply of borated water 1s available for l
' volume and boron concentration ensure that: (1) sufficient water is available l_ within containment'to aermit recirculation cooling flow to the core and (2) the reactor will remain su) critical in the cold condition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA i analyses. )
L The contained water volume limit includes an allowance for water not usable because of tank discharge line location or other physical characteristics.
SEABROOK - UNIT 1 B 3/4 5-2 Amendment No. 6 I
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EMERGENCY CORE'C00 LING SYSTEMS
. BASES 3/4.5.2and3/4.5.3 ECCS SUBSYSTEMS (Continued)
' The limits on contained water volume and boron concentration of the RWST also 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 corrosion on mechanical systems and components.
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SEABROOK --UNIT 1 B 3/4 5-3 Amendment No.-6,
Section IV Determination Of Significant flazards For The Proposed Change l
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IV. D'ETERMINATION OF SIGNIFICANT IIA 7,ARDS FOR TIIE PROPOSED CIIANGE License Amendment Request (LAR) 98-17 proposes a change to the Seabrook Station Technical Specification (TS) Surveillance Requirement (SR) 4.5.2b.1 to remove the prescriptive requirements of using the venting process as the sole means to verify that the Emergency Core Cooling System (ECCS) piping is full of water. Removal of the prescriptive requirements will provide North Atlantic operational flexibility and will allow the use of alternative techniques to verify the ECCS piping is full of water. In addition, the Bases associated with TS 3/4.5.2 will be expanded to reflect the intent of the surveillance requirement.
The proposed change is similar to SR 3.5.2.3 and its associated Bases contained in NUREG-1431,
" Standard Technical Specifications - Westinghouse Plants," Rev.1, April 1995. In addition, the proposed change is based on License Amendments for Commonwealth Edison Company's Byron Station Units 1 & 2 and Braidwood Station Units 1 & 2, that were approved by the NRC Staff as License Amendments 79 and 71, on February 16,1996.
In accordance with 10 CFR 50.92, North Atlantic has reviewed the attached proposed change and has concluded that it does not involve a significant hazards consideration (SHC). The basis for the conclusion that the proposed change does not involve a SHC is as follows:
- 1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed change does not adversely affect accident initiators or precursors nor alter the design assumptions, conditions, configuration of the facility or the manner in which the plant is operated. The proposed change does not alter or prevent the ability of structures, systems and components (SSCs) to perform their intended function to mitigate the consequences of an initiating event within the acceptance limits assumed in the Updated Final Safety Analysis Report (UFSAR).
Removal of the prescriptive requirements will not subject the ECCS system to conditions adverse to nuclear safety. The proposed change does not affect the source term, containment isolation or radiological release assumptions used in evaluating the radiological consequences of an accident previously evaluated in the Seabrook Station UFSAR. The use of proven alternative techniques to verify that the ECCS piping is full of water will continue to ensure that the ECCS system is capable of performing its intended designed safety function. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed change does not alter the design assumptions, conditions, configuration of the facility or the manner in which the plant is operated and maintained in a state of readiness.
Existing system and component redundancy is not being changed by the proposed change. The proposed change has no adverse af fect on component or system interactions. The use of proven alternative techniques to verify that the ECCS piping is full of water will continue to ensure that the ECCS system is capable of performing its intended designed safety function. Therefore, since
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il th'ere are no changes to the design assumptions, conditions, connguration of the facility, or the manner in which the plant is operated and maintained in a state of readiness, the proposed change does not create the possibility of a new or different kind of accident from any previously .
analyzed.
- 3. Involve a significant reduction in a margin of safety.
The proposed change does not adversely affect equipment design or operation and there are no changes being. made to the Technical Specification required safety limits or safety system 4
settings that would adversely affect plant safety. The proposed change does not change the intent of the surveillance requirement of ensuring that the system will perform properly, injecting its full capacity into the RCS upon demand without subjecting the system to hydraulic transients, pump cavitation, and pumping of non-condensable gas (e.g., air, nitrogen, or hydrogen) into the reactor vessel following a safety injection (SI) signal or during shutdown cooling. l Thus, it is concluded that the ECCS will continue ta % available upon demand to mitigate the consequences of an accident and, therefore, there is no significant reduction in a margin of 3 safety. !
l Based on the above evaluation, North Atlantic concludes that the proposed change does not constitute a significant hazard.
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Sections V & VI Proposed Schedule for License Amendment Issuance and Effectiveness ;
and EnvironmentalImpact Assessment i
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V. PROPOSED SCilEDULE FOR LICENSE AMENDMENT ISSUANCE AND EFFECTIVENESS North Atlantic requests NRC review of License Amendment Request 98-17 and issuance of a license amendment by February 26,1999, having immediate effectiveness and implementation required within 60 days. North Atlantic requests this review and approval schedule to allow utilization of the alternate techniques to minimize personnel radiation exposure and the potential exposure to high pressure Guids, and to minimize the time that ECCS valves are open.
l VI. ENVIRONMENTAL IMPACT ASSESSMENT l North Atlantic has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations. The proposed change does not involve a signiGennt hazards consideration, nor increase the types and amounts of efGuent that may be released offsite, nor signiGeantly increase individual or cumulative occupational radiation exposures. Based on the foregoing, North Atlantic concludes that the proposed change meets the criteria delineated in !
10CFR51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact !
Statement.
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