ML20005H325

Proposed Tech Specs,Reducing Min RHR Flow Rate During Mode 6 Operations

ML20005H325
Person / Time
Site:	Sequoyah
Issue date:	01/12/1990
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20005H323	List: ML20005H322 ML20005H325
References
NUDOCS 9001240427
Download: ML20005H325 (7)

Text

9 ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 i DOCKET NOS. 50-327 AND 50-328 (7NA-SQN-TS-89-02) -

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LIST OF AFFECTED PAGES Unit 1 i 3/4 9-8

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Unit 2 3/4 9-9 B3/4 9-2  !

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REFUELING OPERATIONS j 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION ( '

{L ALL WATER LEVELS 1

LIMITING CONDITION FOR OPERATION rP l

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3.9.8.1 At least one residual heat removal (RHR) loop shall be in operation.

APPLICABILITY: MODE 6.

ACTION: *

a. With less than one residual heat removal loop in operation, except  !

as provided in b. below, suspend all operations involving an increase  !

in the reactor decay heat load or a reduction in boron concentration of the Reactor Coolant System. Close all containment penetrations providing direct access from the containment atmosphere to the ,

outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

b. The residual heat removal loop may be removed from operation for up to I hour per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period during the performance of CORE ALTERATIONS in the vicinity of the reactor pressure vessel hot legs,

c. The provisions of Specification 3.0.3 are not applicable.

( I SURVEILLANCE REQUIREMENTS .

sl.t h less +han 276 hours0.00319 days <br />0.0767 hours <br />4.563492e-4 weeks <br />1.05018e-4 months <br /> since subcroficoloty, at  !

4.9.f.l.) 0.0.0.1 AM least one residual heat removal loop shall be verified to be in pp operation and circulating reactor coolant at a flow rate of greater than or equal to 2500 gpm at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

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'I,K 4.*) . 6L ?. Hith greoler tha n or e vaIlo 278 hours0.00322 days <br />0.0772 hours <br />4.596561e-4 weeks <br />1.05779e-4 months <br /> since soberMic.aldy, at lces+ one residua l heat remova l loop shall be veriNed to be in '

ope ro sion and c.lrc.ulo}lry rectcic>r c.co lan4 al a flow rate of .

greater tha n o r- e val to 2.coogpm a t. leas + once perg?. hours.

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' September 17, 1980

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3/4 9-8 SEQUOYAH - UNIT-1 i

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REFUELING OPERATIONS .I BASES 3/4.9.6 MANIPULATOR CRANE The OPERABILITY requirements for the manipulator cranes ensure that:

1) manipulator cranes will be used for movement of drive rods and fuel assemblies,

2) each crane has suf ficient load capacity to lift a drive rod or fuel assemoly, j and 3) the core internals and pressure vessel are protected from excessive ,

lifting force in the event they are inadvertently engaged during lifting operations. ,

3/4.9.7 CRANE TRAVEL - SPENT FUEL PIT AREA

, , , The restriction on movement of loads in excess of the nominal weight of a fuel and control rod assembly and associated handling tool over other fuel assemblies in the storage pool ensures'that in the event this load is dropped:

1) the aciOvity release will be limited to that contained in a single fuel -

assembly, and 2) any possible distortion of fuel in the storage racks will not result in a critical array. This assumption is consistent with the activity release assumed in the accident analyses.

3/4.9.8 RESIDUAL' HEAT REMOVAL AND COOLANT CIRCULATION ( l The requirement that at least one residual heat removal (RHR) loop be in operation ensures that; 1) sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor pressure vessel below 140'F -

as required during the REFUELING MODE, and 2) sufficient coolant circulation is maintained through the reactor core to miniWe +ha a Har+e af incident and prevent boron stratification, pd tNSERT A] boron dilution ,

TP The requirement to have two RHR loops OPERABLE when there is less than A; 23 feet of water above the reactor pressure vessel flange ensures that a .

single failure of the operating RHR loop will not result in a complete loss of t - Tl '.

residual heat removal capability. With the reactor vessel head removed and E 23 feet of water above the reactor pressure vessel flange, a large heat sink if '

is available for core cooling. Thus, in the event of a failure of the d' operating RHR loop, adequate time is provided to initiat'e emergency procedures Q!

to cool the core. '

3/4 9.9 CONTAINMENT VENTILATION SYSTEM '

The OPERABILITY of this system ensures that the containment vent and i pdrge penetrations will be automatically isolated upon detection of high '

radiation levels within the containment. The OPERABILITY.of this system is ,

required to restrict the release of radioa-tive material from the containmant . 4 atmosphere to the environment. [ .

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SEQUOYAH - UNIT 1 B 3/4 9-2 SEP 171980 .)

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The reduction of the minimum required flow rate after 278 hours0.00322 days <br />0.0772 hours <br />4.596561e-4 weeks <br />1.05779e-4 months <br /> following i subtriticality reduces the probability of losing an RHR pump by >

air-entrainment from pump vortexing. This is a particular concern during i reduced RCS inventory operation. The 278-hour value is based on required i decay heat removal, and the 2000 gpm value is limited by cavitation in.the j control valve and valve chattering in the 10-inch check valve.  ;

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(, 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION ALL WATER LEVELS LIMITING CONDITION FOR OPERATION 3.9.8.1 At least one residual heat removal (RHR) loop shall be in, operation.

APPLICABILITY: MODE 6. .

ACTION:

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a. With less than one residual heat removal loop in operation, 2xcept as provided in b. below, suspend all operations involving an increase in the reactor decay heat load or a reduction in boron concentration ,

of the Reactor Coolant System. Close all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

b. The residual heat removal loop may be removed from operation for up to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period during the performance of-CORE ALTERATIONS in.the vicinity of the reactor pressure vessel hot legs.

c. The provisions of Specification 3.0.3 are not applicable.  ;

SURVEILLANCE REQUIREMENTS l With less than 2.76 hours8.796296e-4 days <br />0.0211 hours <br />1.256614e-4 weeks <br />2.8918e-5 months <br /> since, suberHicalify > a k  ;

+.9.8.l.l 4.0.^.F AM least one residual heat removal loop shall be verified to be in e*

operation and circulating reactor coolant at a flow rate of greater than or f equal to 2500 gpm at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, s.2

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4. % til.2. With 3 realer than or egual le 278 hsors since subtroWealdy ,

at Icos+ one. ' resids t heat e e move I Inp shau be veroned to bs in opera Ubn and cire.platiny reac. lor coola n t at 0 ll* W r* I*

• t oP 3 realte ihan oe e veI do 2.000 ypen , ed leas + o n c e. p e r- '

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' o SEQUOYAH - UNIT 2 3/4 9-9 -

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REFUELING OPERATIONS BASES 3/4.9.6 MANIPULATOR CRANE l

The OPERABILITY requirements for the manipulator cranes ensure that:

1) manipulator cranes will be used for movement of drive rods and fuel

• assemblies,

2) each crane has sufficient load capacity to lift a-drive rod or fuel assembly, assembly, and 3) the core internals and pressure vessel are protected from ,

excessive lifting force in the event they are inadvertently engaged during lifting operations.

3/4.9.7 CRANE TRAVEL - SPENT FUEL PIT AREA  !

The restriction on movement of loads in excess of the nominal weight of a '

fuel and control rod assembly and associated handling tool over other fuel assemblies in the storage pool ensures that in the event this load is dropped .

1) the activity release will be limited to that contained in a single fuel '

assembly, and 2) any possible distortion of fuel in the storage racks will not result in a critical array. This assumption is consistent with the activity release assumed in the accident analyses.

3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION The requirement that at least one residual heat removal (RHR) loop be in operation ensures that; 1) sufficient cooling capacity is available to remove '

decay heat and maintain the water in the reactor pressure vessel below 140*F as required during the REFUELING MODE, and 2) sufficient coolant circulation is maintained thru the reactor core to mini 'n th; c "ade af ron dilution

incident and prevent boron stratification. Add /NS GRT' .

The requirement to have two RHR loops OPERABLE when there is less than 9 23 feet of water above the reactor pressure vessel flange ensures that a dl single failure of the operating RHR loop will not result in a complete loss of M residual heat removal capability. With the reactor vessel head removed and  ?

l 23 feet of water above the reactor pressure vessel flange, a large heat sink 4 is available for core cooling. Thus, in the event of a failure of the operating '

d RHR loop, adequate time is provided to in!tiate emergency procedures to cool

! the core.

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1; t 3/4.9.9 CONTAINMENT VENTILATION SYSTEM ii.

(

The OPERABILITY of this system ensures that the containment vent and

• purge penetrations will be automatically isolated upon. detection of high radiation levels within the containment. The OPERABILITY of this' system is . ..

required to restrict the release of' radioactive material from the containment:  ;

atmosphere to the environment.

j SEQUOYAH - UNIT 2 B 3/4 9-2 j

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INSERT A The reduction of the minimum required flow rate after 278 hours0.00322 days <br />0.0772 hours <br />4.596561e-4 weeks <br />1.05779e-4 months <br /> following suberiticality reduces the probability of losing an RHR pump by air-entrainment from pump vortexing.. This is a particular concern during reduced RCS inventory operation. The 278-hour value is based on required decay heat removal, and the 2000 gpm value is limited by cavitation in the control valve and valve chattering in the 10-inch check valve.

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