ML20134L056

Proposed Tech Specs Re Changes Made Concerning Decay Heat Removal Sys Valve

ML20134L056
Person / Time
Site:	Davis Besse
Issue date:	02/13/1997
From:	CENTERIOR ENERGY
To:
Shared Package
ML20134L055	List: ML20134L052 ML20134L056
References
NUDOCS 9702180234
Download: ML20134L056 (7)

Text

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Dock 2t Number 50-346 l*'

4 Li*2ntge Number NPF-3 c

Serial Number 2449

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INFORMATION ONLY DiERGENCY CORE COOLING SYSTEMS ECCS SUBSYSTDtS - T A 280*F

_L1HITING CONDITION FOR OPERATION f

3.5.? Two independent ECCS subsystems shall be OPERABLE with each subsystem comprised of:

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

b.

Ode OPERABLE low pressure infection (LPI) pump.

One OPERABLE decay heat cooler, and c.

d.

An OPERABLE flow path capable of taking suction from the borated water storage tank (BWST) on c safety injection signal and senually transferring suction to the containment sump during the recintulation phase of operation.

i

_ APPLICABILITY: N0 DES 1. 2 and 3, ACTION:

j With one ECCS subsystem inoperable, restore the inoperable a.

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 2

SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

b.

In the event the ECCS is actuated and infects water into the Reactor Coolant System, a Special Report shall be prepared and subnitted to the Conaission pursuant to Specification 6.9.2 within 90 days describing the circumstances of the actuation and the total accuasslated actuation cycles to.da,te.

_ SURVEILLANCE REOUIREMENTS i

J 4.5.2 Each ECCS subsystem shall be denenstrated OPERABLE:

a.

At least once per 31 days b verifyin that each valve 1

power operated or automEtic in the ffow path that is no(manufkh.

t lo seated or othentise secured in position, is in its correct position.

DAVIS-BESSE. UNIT 1 3/4 5-3 Amendment No. 36.182 9702180234 970213 PDR ADOCK OSOOO' 46 J

p PDR

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Dockst Number 50-346 T.

License Number NPF-3 INFORMATION ONDg

. Attschment 1 Paga 3 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

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drained by verifying that the ECCS piping is full of water by venting the ECCS pump casings.and discharge piping high points. **

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By a visual inspection which verifies that no loose debris (rags, trash, c.

clothing, etc.) is present in the containment which could be transported to the 1

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:

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 DH-12 is not required if th'e 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 suno recirculation valves energized, the BWST Outlet Valve HV-DH7A (HV-DH78) automatically close in 575 seconds after the operator manually pushes the control switch to open the Containment Emergency Sump Valve HV-OH9A (HV-bH98) which should be verified to open in 575 seconds.

3.

Deleted

• • The requirements of this surveillance may be deferred until the Tenth Refueling Outage for the ECCS flowpath which does not have manual high point venting capability.

DAVIS-BESSE. UNIT 1 3/4 5-4 Amendment No. 3.25.28.40.77.

135.182.195.196.208 4

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_.s.

Docket Number 50-346 Licanad Number NPF-3 Sbrial Number 2449 Page 4 EMERGENCY CORE COOLING SYSTEMS SURVFil I. ANCE REOUIREMENTS (Continued) 4.

Verifying that a minimum of 290 cubic feet of trisodium phosphate dodecahydrate (TSP)is contained within the TSP storage baskets.

5.

Deleted 6.

Deleted

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e.

At least once per 18 months, during shutdown, by 1.

Verifying that each automatic valve in the flow path actuates to its correct position on a safety injection test signal.

2.

Verifying that each HPI and LPI pump starts automatically upon receipt of a SFAS test signal.

f.

By performing a vacuum leakage rate test of the watertight enclosure for valves DH-11 and DH-12 that assures the motor operators on valves DH-11 and DH-12 will not be flooded for at least 7 days following a LOCA:

1.

At least once per 18 months.

2.

After each opening of the watertight enclosure.

3.

After any maintenance on or modification to the watertight enclosure which could affect its integrity.

The inspection port on the watertight enclosure may be opened without requiring nerformance of the vacuum laakaoe rate fact to perform insnections. After use. the inspection nort must be verified as closed in its correct nosition. Provisions of TS 3.0.3 are not nonlicable durine these insnections.

g.

By verifying the correct position of each mechanical position stop for valves DH-14A and DH-14B.

1.

Within~4 hours following completion of the opening of the valves to their mechanical position stop or following completion of maintenance on the valve when the LPI system is required to be OPERABLE.

2.

At least once per 18 months.

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DAVIS-BESSE, UNIT 1 5/45-5 Amendment No. 26,40,191,207, i

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._......- - - ~... ~ ~

Dockst" Number 50-346

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Liccnse Number NPF-3 Strial Number 2449 4:::?"

IMFORMATION ONLY i

i EMERGENCY CORE COOLING SYSTEMS p

SU2VEILLANCE REQUIREMENTS (Continued) a f

h.

By performing a flow balance test, during shutdown, following completion of modifications to the HPI or LPI subsystems that alter the subsystem flow characteristics and verifying the

-following flow rates:

HPI System - Single Pump Injection Leg 1-1 3 375 gom,at 400 psig* '

injection Leg 1-2 1 375 spm at 400 psig*

Injection Leg 2-1

> 375 gpm at 400 psig*

Injection Leg 212 E375gpmat400psig*

l LPI System - Single Pump s

Injection Leg 1

.t 2650 gpm at 100 psig**

i Injection Leg 2 1 2650 gpa at 100' psig**

t j.

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Reactor coolant pressure at the HPI nozzle in the reactor coolant

~pump discharge.

Reactor coolant pressure at he core flood nozzle on the reactor vessel.

2 1

DAVIS-BESSE. UNIT 1 3/4 5-Sa Araende.ent No. 20

.... A

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{ 06cket* Number 50-346 Licente Humber NPF-3 Sarial Nu5tber.2449 i Attac'hmqnt 1 Pe.ga 6 3/4.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) ea8 280 F ensures that sufficient emergency core

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capability will be available.in the event of a LOCA assuming the loss of i

one subsystem through any sin'gle failure consideration.

3 operating in conjunction with the core flooding tanks is capable ofEither subsystem supplying. sufficient core-cooling to maintain the peak cladding a

i temperatures within acceptable limits for all postulated break sizes j

ranging from the double ended break of the largest RCS cold leg pipe downward.

In addition, each ECCS subsy. stem provides long term core-cooling capability in the recirculation mode during the accident recovery period i

OAVIS-BESSE, llNIT 1 B 3/4 5-1 Amendment No. 20,191 a.

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l EMERGENCY CORE COOLING SYSTEMS Licensa Number NPF-3 Serial Number 2449 j

BASEg _

Page 7 i

With the RCS temperature below 280 F, one OPERABLE ECCS subsystem is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the limited core i

cooling requirements.

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The Surveillance Requirements provided to ensure OPERABILITY cf each component ensures that, at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is mamtained.

ne function of the trisodium phosphate dodecahydrate (TSP) contained in baskets located in the j

containment normal sump or on the 565' elevation of containment adjacent to the normal sump, is to neutralize the acidity of the post-LOCA borated water mixture during containment emergency sump recirculation. The borated water storage tank (BWST) borated water has a nominal pH value of 1

approximately 5. Raising the borated water mixture to a pH value of 7 will ensure that chloride stress i

corrosion does not occur in austenitic stainless steels in the event that chloride levels increase as a result

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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 i

L system.

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j-He Surveillance Requirement (SR) associated with TSP ensures thr+ the minimum required volume of TSP is stored in the baskets. The minimum required volume of TSP is the volume that will achieve a j

post-LOCA borated water mixture pH of 2 7.0, conservatively considering the maximum possible sump water volume and the maximum possible boron concentration. The amount to TSP required is based on L

the mass of TSP needed to achieve the required pH. However, a required volume is verified by the SR, i

rather than the mass, since it is not feasible to weigh the entire amount of TSP in containment. He j

minimum required volume is based on the manufactured density ofTSP (53 lb/ft'). Since TSP can have a tendency to agglomerate from high humidity in the containment, the density may increase and the l

volume decrease during normal plant operation, however, solubility characteristics am not expected to change. Herefore, considering possible agglomeration and increase in density, verifying the minimum j

l volume of TSP in containment is conservative with respect to ensuring the capability to achieve the j

l minimum required pH. He minimum required volume of TSP to meet all analytical requirements is 250

)

i ft'. He surveillance requirement of 290 ft' includes 40 ft' of spare TSP as margin. Total SE capacity is 325 ft'.

Decav Heat Removal System valves DH-11 and DH-12 are lacatad in an area that would be flooded I

followine a LDCA. Thaea valves are loca**d in a watertieht anclaanre to enanrrheir onerability un to seven davs following a LOCA. Surveillance Renniraments are nrovided to veri he accentable ieak tiehenace of this enclosure. An inenaction nort is laratad on this watadioht enclu91r. which is tynically j

naad for nerformine in=nartions incide the enclosure. Durine the v=enum taak==a rate test the in=_naction j

n_ ort is in a claaad nacitian and subiect to the tent This inenactian nort may be enhaanuentiv onened for j

une in viewine camnanents incide the enclosure. Onanino thin inenactian nort will not reauire i

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nerformance of the vacuum laak=ne rate test harance of the demien of the closure fittine which will nreclude la knee under LOCA conditions. when closed.

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Surveillance requirements for throttle valve position stops and flow balance 6estag provide assurance j

that proper ECCS flows will be maintained in the event of a LOCA. Maintenance of proper flow i

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 resistance j

configuration, (2) provide the proper flow split between injection points in accordance with the j b assumptions us' d in the ECCS-LOCA analyses, and (3) provide an acceptable level of total ECCS flow e

i to all injection points equal to or above that assumed in the ECCS-LOCA analyses.

i DAVIS-BESSE, UNIT I B 3/4 5-2 Amendment 140. 20,123,182,191,195, 207,

Docket Number 50-346 L

Licznsa Number UPF-3 Sarial Number 2449

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EMERGENCY CORE COOLING SYSTEMS pf2SES (Continued)

Containment Emergency Sump Recirculation Valves DH-9A and DH-98 are de-energized during H0 DES 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 i

DH-78 are de-energized during H0 DES 1, 2, 3, and 4 to preclude postulated

~ 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-70 is permitted w an intermittent basis during H0 DES 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.

3 /4. 5.4 BORATED WATER STORAGE TANK t

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 4

switchover to the recirculation mode, and 2)

The reactor will remain at least 1% Ak/k subcritical in the cold i

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.

i 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 concentration to within limits w;s developed considering the time required to change boron concentration or temperature and assuming that the contents of th' BWST are still available for injection.

e 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 boron 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 aad caustic stress corrosion cracking on mechanical systems and components.

DAVIS-BESSE, UNIT 1 8 3/4 5-2a,

Amendment No.19b 207 L