Text

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)
	v • d • e

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) i i

LIST OF AFFECTED PAGES Unit 1 i

3/4 9-8 B3/4 9-2 Unit 2 3/4 9-9 B3/4 9-2 b

8

.i I

A s.

e

)

O h

e.

e-e 900124042790011g7 pus nooexosoogig P

4

}

,.. __-~ ;;; z 3...J '

.2

\\

REFUELING OPERATIONS j

3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION

(

{L ALL WATER LEVELS 1

LIMITING CONDITION FOR OPERATION rP l

\\

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 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

b.

The residual heat removal loop may be removed from operation for up to I hour per 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 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 I

sl.t h less +han 276 hours0.00319 days 0.0767 hours 4.563492e-4 weeks 1.05018e-4 months 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 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

.s !

Q.

'I,K 4.*). 6L ?.

Hith greoler tha n or e vaIlo 278 hours0.00322 days 0.0772 hours 4.596561e-4 weeks 1.05779e-4 months 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 a t. leas + once perg?. hours.

2.coogpm

.h

' September 17, 1980

)

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

4 i

. _ n; c -

n..

~-

U: ' '

a

I 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. [

2

+

SEP 171980

.)

SEQUOYAH - UNIT 1 B 3/4 9-2 y

4

,4 -

+.n

1 e

INSERT A The reduction of the minimum required flow rate after 278 hours0.00322 days 0.0772 hours 4.596561e-4 weeks 1.05779e-4 months 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.

4 l

1 1

i i

.p 9

I-t f

4 I

e t

'I +

6

'E

(

L l

f f

e l

i.

~..

[- l i

t:

o

~;

a....: __

,w

7-REFUELING OPERATIONS e(,

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:

~

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 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

b.

The residual heat removal loop may be removed from operation for up to 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 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 0.0211 hours 1.256614e-4 weeks 2.8918e-5 months 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 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , s.2

'.\\

t

'f, 4

le 278 hsors since subtroWeald,

4. % til.2. With 3 realer than or egual y

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-I2 h ov r o.

^

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

4

~

tr; 1 !

j i

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

?

23 feet of water above the reactor pressure vessel flange, a large heat sink 4

l 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.

1; t 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

d' 2,

l

~*

+ u}

L u

~

INSERT A The reduction of the minimum required flow rate after 278 hours0.00322 days 0.0772 hours 4.596561e-4 weeks 1.05779e-4 months 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.

i i

e e

'l I

.f I

5 i

t i

s. 6 6 h'

1,

-t

$l

' )I [t o,

<l j

j, t

(

i

=,

i.

l

- j.

.' 44 l

^

1, i

,-W

'

ML20005H325

Text

Navigation menu

Search