ML20101C696

Proposed Tech Specs,Allowing Deferment of SR 4.5.2.b for ECCS Flowpath Containing HPI Pump 1-2 Until 10th Refueling Outage,Scheduled to Begin 960408

ML20101C696
Person / Time
Site:	Davis Besse
Issue date:	03/06/1996
From:	CENTERIOR ENERGY
To:
Shared Package
ML20101C689	List: ML20101C687 ML20101C691 ML20101C696
References
NUDOCS 9603190146
Download: ML20101C696 (7)

Text

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INFORMATION ONLY EMERGENCY CORE COOLING SYSTEMS ECCS SUBSYSTEMS - T .... A 280*F WWg LIMITING CONDITION FOR OPERATION 3.5.2 Two independent ECCS subsystems shall be OPEPABLE with each subsystem comprised of:

a. One OPERABLE high pressure injection (HPI) pump,

b. One OPERABLE low pressure injection (LPI) pump,

c. One OPERABLE decay heat cooler, and MR d. An OPERABLE flow path capable of taking suction from the 8N borated water storage tank (BWST) on a safety injection signal and manually transferring suction to the containment sump during the rectreulation phase of operation.

APPLICABILITY: MODES 1. 2 and 3.

ACTION:

a. With one ECCS subsystem inoperable, restore the inoperable subsystem 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 HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. j

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b. In the event the ECCS is actuated and injects water into the Reactor Coolant System, a Special Report shall be prepared and submitted to the Comission pursuant to Specification 6.9.2 within 90 days describing the circumstances of the actuation l and the total accumulated actuation cycles to date.

SURVEILLANCE REOUIREMENTS 4.5.2 Each ECCS subsystem shall be demonstrated OPERABLE:

a. <

At least once per 31 days by verifying that each valve (manugl.

power operated or automatic) in the flow path that is not locked, sealed or otherwise secured in position is in its correct position.

DAVIS-BESSE. UNIT 1 3/4 S.3 Amendment No. 36 182 9603t90t46 960306 6 DR ADOCK 0500

Revised by NRC Letter Dated June 6. 1995 SURVEILLANCE REQUIREMENTS (continued)

b. At least once per 18 months, or prior to operation after ECCS piping has been drained by verifying that the ECCS piping is full of water by venting the ECCS pump casings and discharge piping high points.**

c. By a visual ins clothing, etc.)pection which verifies that no loose debris (rags, trash,is present in the to the containment emergency sump and cause restriction of the pump suction during LOCA conditions. This visual inspection shall be performed:

1. For all accessible areas of the containment prior to establishing CONTAINMENT INTEGRITY and

2. For all areas of containment affected by an entry, at least once daily while work is ongoing and again during the final exit after completion of work (containment closeout) when CONTAINMENT INTEGRITY is established,

d. At least once per 18 months by:

1. Verifying that the interlocks: ,

1 a) Close DH-11 and DH-12 and deenergize the pressurizer heaters, if either DH-11 or DH-12 is open and a simulated reactor coolant system pressure which is greater than the trip setpoint

(<438 psig) is applied. The interlock' to close DH-11 and/or 1 ,

DH-12 is not required if the valve is closed and 480 V AC power is disconnected from its motor operators.

b) Prevent the opening of DH-11 and DH-12 when a simulated or actual reactor coolant system pressure which is greater than the trip setpoint (<438 psig) is applied.

2. a) A visual inspection of the containment emergency sump which verifies that the subsystem suction inlets are not restricted by debris and that the sump components (trash racks, screens, etc.) show no evidence of structural distress or corrosion.

b) Verifying that on a Borated Water Storage Tank (BWST) Low-Low Level interlock trip, with the motor operators for the BWST outlet isolation valves and the containment emergency sump ,

recirculation valves energized, the BWST Outlet Valve HV-DH7A l (HV-DH78) automatically close in <75 seconds after the operator manually pushes the control switcli to open the Containment Emergency Sump Valve HV-DH9A (HV-DH98) which should be verified to open in <75 seconds.

3. Deleted DAVIS-BESSE. UNIT 1 3/4 5-4 Amendment No. 3.25.28.40.//.

I25.IB2.195.196

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hk.nMQM y C atap for Ah. Ecc3 flowpaM w4ud doc.s nd have mana/ 694 poid nd"). co.pdtl;f,y.

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I 3/4.5 EMERGENCY CORE C00llNG SYSTEMS (ECCSI BASES 3/4.5.1 CORE FLOODING TANKS The OPERABILITY of each core flooding tank ensures that a sufficient volume of borated water will be immediately forced into the reactor vessel in the event the RCS pressure falls below the pressure of the tanks. This initial surge of water into the vessel provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on volume, boron concentration and pressure ensure that the assumptions used for core flooding tank injection in the safety analysis are met.

The tank power operated isolation valves are considered to be

" operating bypasses in the context of IEEE Std. 279-1971 which requires thatbypassesofaprotectivefunctionberemovedautomatIcallywhenever permissive conditions are not met. In addition, as these tank isolation valves fail to meet single failure criteria, removal of power'to the yalves is required.

l The one hour limit for operation with a core flooding tank CFT) inoperable for reasons other than baron concentration not withi(n limits minimizes the time the plant is exposed to a possible LOCA event occurring with failure of a CFT, which may result in unacceptable peak cladding temperatures.

the condition must With be boron concentration corrected for oneThe within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. CFT72 not within hour limitlimits, was developed considering that the effects of reduced boron concentration on core subcriticality during reflood are minor. Boiling of the ECCS water in the core during reflood concentrates the baron in the saturated liquid l that remains in the core. In addition, the volume of the CFTs is still l available for injection. Since the boron requirements are based on the average boron concentration of the total volume of both CFTs, the consequences are less severe than they would be if the contents of a CFT were not available for injection.

The completion times to bring the olant to a MODE in which the Limiting Condition for Operation (LCO? does not apply are reasonable based on operating experience. The completion times allow plant conditions to be changed in an orderly manner and without challenging plant systems.

! CFT boron concentration sam lin within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after an 80 gallon l

volume increase will identify whetker inleakage from the RCS has caused a

reduction in boron concentration to below the required limit. It is not necessary to verify boron concentration if the added water inventory is because the water contained fromthebora'tedwaterstoragetank(BWST)ionrequirements.

in the BWST is within CFT boron concentrat 3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS The operability of two independent ECCS subsystems with RCS average l temperature 3 280 F ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of I

one subsystem through any single failure consideration. Either subsystem

'. operating in conjunction with the core flooding tanks is capable of supplying sufficient core cooling to maintain the peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem provides long term core cooling capability in the recirculation mode during the accident recovery period.

DAVIS-BESSE, UNIT 1 Amendment No. 20,191 8 3/4 5-1 i

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. EMERGENCY, CORE COOLING SYSTEMS BASES With the RCS temperature below 280*F, one OPERABLE ECCS subsp tem is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the limited core cooling  ;

requirements.

l The Surveillance Requirements provided to ensure OPERABILITY of each component ensures that, at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is maintained. l The function of the trisodium phosphate dodecahydrate (TSP) contained in baskets in the containment normal sump is to neutralize the acidity of the post-LOCA borated water mixture prior to establishing containment emergency sump recirculation. The borated water storage tank (BWST).

borated. water has a nominal pH value of approximately 5. Raising the borated water mixture to a pH value of 7 will ensure that chloride stress corrosion does not occur in austenitic stainless steels lii the event that chloride levels increase as a result of contamination on the surfaces of the reactor containment building. Also, a pH of 7 is assumed for the containment emergency sump for iodine retention and removal post-LOCA by the containment spray system.

The Surveillance Requirements (SR) associated with TSP ensure that the minimum amount and density of TSP is stored in the baskets, and that the TSP in the baskets is sufficient to provide adequate, post-LOCA, long-term pH adjustment.

Surveillance requirements 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 flow resistance.

and pressure drop in the piping system to each injection point is necessary to: (1) prevent total pump flow from exceeding runout conditions when the system is in its minimum risistance configuration, (2) provide 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.

Containment Emergency Sump Recirculation Valves DH-9A and DH-98 are de-energized during MODES 1, 2, 3 and 4 to preclude postulated inadvertent

_ opening of the valves in the event of a Control Room fire, which could result in draining the Borated Water Storage Tank to the Containment Emergency Sump and the loss of this water source for normal plant shutdown. Re-energization of DH-9A and DH-98 is permitted on an intermittent basis during MODES 1, 2, 3 and 4 under administrative controls. Station procedures identify the precautions which must be taken when re-energizing these valves under such controls.

Borated Water Storage Tank (BWST) outlet isolation valves DH-7A and DH-78 are de-energized during MODES 1, 2, 3, and 4 to preclude postulated DAVIS-BESSE, UNIT 1 B 3/4 5-2 Amendment No.D,JD,AM,MA,195

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INFORMATION ONLY EMERGENCY CORE COOLING SYSTEMS BASES (Continued) inadvertent closure of the valves in the event of a fire, which could result in a loss of the availability of the BWST. Re-energization of valves DH-7A and DH-7B is permitted on an intermittent basis during MODES  ;

1, 2, 3, and 4 under administrative controls. Station procedures  :

identify the precautions which must be taken when re-energizing these valves under such controls. l l

3/4.5.4 BORATED WATER STORAGE TANrs The OPERABILITY of the borated water storage tank (BWST) 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 the BWST minimum volume and boron concentration ensure that:

1) sufficient water is available within containment to permit recirculation cooling flow to the core following manual switchover to the recirculation mode, and

2) The reactor will remain at least 1% Ak/k subcritical in the cold condition at 70*F, xenon free, while only crediting 50% of the control rods' worth following mixing of the BWST and the RCS water volumes.

These assumptions ensure that the reactor remains subcritical in the cold condition following mixing of the BWST and the RCS water volumes.

With either the BWST boron concentration or BWST borated water temperature not within limits, the condition must be corrected in eight hours. The eight hour limit to restore the temperature or boron l' concentration to within limits was developed considering the time required to change boron concentration or temperature and assuming that the contents of the BWST are still available for injection.

The bottom 4 inches of the BWST are not available, and the instrumentation is calibrated to reflect the available volume. The limits on water volume, and baron concentration ensure a pH value of between 7.0 and 11.0 of the solution sprayed within the containment after a design basis accident. The pH band minimizes the evolution of iodine and minimizes the effect of chloride and caustic stress corrosion cracking on mechanical systems and compenents.

DAVIS-BESSE, UNIT 1 B 3/4 5-2a Amendment No.191

Docket Number 50-346

. License Number NPF-3  ;

. Serial Number 2367 Attachment 2 i 4 Page 1 I i

i EWIIKMNTAL ASSES! MEN l Identification of Proposed Action This proposed action involves the Davis-Basse Nuclear Power Station (DBNPS), Unit Number 1, Operating License Number NPF-3, Appendix A,  ;

Technical Specifications (TS). A license amendment request is proposed to revise TS 3/4.5.2, " Emergency Core Cooling Systems, ECCS Subsystems - l Tavg a 2800F." The current TS Action Statement 3.5.2.a requires that,  !

due to inoperability of ECCS subsystem Train 2, the plant be placed in Hot Shutdown (Mode 4) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of the expiration of the 72-hour allowed outage time on March 7, 1996, at 1354 hours0.0157 days <br />0.376 hours <br />0.00224 weeks <br />5.15197e-4 months <br />.

ECCS subsystem Train 2 is considered inoperable due to the discovery that Surveillance Requirement 4.5.2.b cannot be met for a-section of High Pressure Injection Pump 1-2 discharge piping downstream of normally closed motor operated discharge valve HP2A.

Need for the Proposed Action The changes proposed are needed to allow continued plant operation until the 10RF0 which is scheduled to begin April 8, 1996.

Environmental Impact of the Proposed Action Toledo Edison has determined that the structures, systems and components which could be affected by the proposed license amendment, High Pressure Injection Train 2, will continue to be capable of performing its safety functions.

The proposed license amendment will reduce the potential for unduly requiring cooldown and heatup transitions of plant equipment, thus pre-serving the cycling margin between plant design and actual operating history, j The proposed license amendment involves a change to a requirement with respect to the use of facility components located within the restricted area as defined in 10CFR Part 20. As discussed in the Significant Hazards Consideration, this proposed license amendment does not involve a significant hazards consideration. The proposed change to allow con-tinued plant operation does not alter source terms, containment isolation j or allowable releases. In addition, the proposed change does not involve an increase in the amounts, and no change in the types, of any radiologi- i cal effluents that may be allowed to be released offsite. Furthermore, there is no increase in the individual or cumulative occupational radiation exposure. j

Docket Number 50-346

, License Number NPF-3 Serial Number 2367 Attdchment 2 l Page 2 With regard to potential non-radiological impacts, the proposed license l amendment involves no increase in the amounts or change in types of any non-radiological effluents that may be released offsite, and has no other environmental impact.

1 Based on the above, Toledo Edison concludes that there are no significant radiological or non-radiological environmental impacts associated with the proposed license amendment.

l Alternatives to the Proposed Action Since Toledo Edison has concluded that the environmental effects of the proposed action are not significant, any alternatives will have only similar or greater environmental impacts. The principal alternative would be not to grant the license amendment. This would not reduce the l environmental impacts attributable to the facility. Furthermore, it would force a shutdown of the facility upon expiration of the allowed outage time of TS Action Statement 3.5.2.a.

Alternative Use of Resources This action does not involve the use of resources not previously con-sidered in the Final Environmental Statement Related to the Operation of the Davis-Besse Nuclear Power Station, Unit Number 1 (NUREG 75/097).

l Finding of No Significant Impact  ;

Toledo Edison has reviewed the proposed license amendment against the criteria of 10CFR51.30 for an environmental assessment. As demonstrated l

above, the proposed license amendment does not involve a significant hazards consideration, does not increase the types or amounts of ef-fluents that may be released offsite, and does not increase individual or cumulative occupaF.ional radiation exposures. Accordingly, Toledo Edison finds that the proposed license amendment, if approved by the Nuclear  !

Regulatory Commission, will have no cignificant impact on the environment 1 and that no Environmental Impact Statement is required.  !

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