ML19309H890

Proposed Changes to Tech Specs,Deleting Requirement to Maintain at Least Three Counts Per Second on Each Source Range Monitor When Only Two Fuel Assemblies Are in Quadrant

ML19309H890
Person / Time
Site:	Dresden, Quad Cities
Issue date:	05/15/1980
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML17192A694	List: ML17192A693 ML19309H890
References
NUDOCS 8005200622
Download: ML19309H890 (14)

Text

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8 006200622 Enclosure 1 Dresden Station Unit 2 Proposed Technical Specification Changes Revised Pages: 151

'152 153 i

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a DPR-19 4.10 SCRVI:!LI.ANCE 1: EQUI!:i .ENT 3.10 1.laitTING CONDITION FOIt OPERATION

-1.10 H EFr':T.TNR

,. 10 REFI'El.!NG Applicability:

Applicability:

Applies to the periodic testing of those interlocks Applies to fuel handling and core reactivity ar.d instruments used during reftteling, li:nitations. .

Objective:

Objective:

To verify the operability of ins'.n:vnentation and To assure core reactivity is within capability of ' interlocks used in refueling.

the ecstrol rc<ls and to prevent criticality during .

refueling.

S;ecification:

Specification: -

1 Itefueling Interlocks

A.

A. Refueling Interlocks Prior to any fuel handlin';. with t'.e heart nff f the reactor vessel. the refueling ir.terlocks The reactor mode switch shall be locked in the "Itefuel" position during core alterations sh?ll be functionally tested. They shall aisc and the refueling interlochs shall be operable e he tec.e>! at wechir int ~rr is th reaftar un::1 except as specifierl in Specifications 3.10.D no lon",' r retiid.ul a d foe ~.cir; nn:, reivir and 3.10. E. lj work associated with ti c interlocks.

l 11 . Core :le titorina B. Core Sionitorin,,

Prior in n:ahinc any alterretin.w to the core Durim; core alterations two Sit 31's shall be the S!t31's shall bc functio ully tested an.!

operable, one in the core quadrant where j checke.1 f:,r rentron re.erme. Thereafter.

fuel or control rods are being moved and one the S;t3 's will i,e chede<* <htily for respnre.,

in an adjacent quadrant. For an S1:31 to be except when the conditions of 3.10.B.2.a considered operable, the following conditions and 3.10 B.2.b are met.

shall be satisfied: .

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DPD-19 8 .

3.10 LI.T*ITING COSD* TION FOlt OPERATION .i.10 SURVEILLANCE REQUIRE.itENT  ;. - -

1. The Sint shall be inser:cd to the nerrnal o;.:ratic; level. (Use of special moveable. .

6:nMn t :ype .:ctectors durir; initial fuel lending and major core aitcrations in place

' of norn.al letectors are p:rmissibic as long as the detector is connected into the .

rern.a1 SR.11 circuit.) *

2. te SIN or dunking type detector shall have a ninirsri of 3 eps with all rods fully inserted .. ,

in the core except when both of the following conditions are fulfillcd: a a) rio note than two fuel assecblies are I' '

present in the core gaadrant associated with the S9'I.

b) thile in core, these fuel assenblies are in locations adjacent to the Sm.

C. Fuel Stora;;c Pool Water Level C. Tucl Storage Pool Water Level Whene.cr irradiated fuel is stored in the fuel steere;c poc!. the paol water leyc1 shall be Whenever irradiated fuel is stored in the m:.in:ained at a level of 30 feet. fuct storage pool, the pool level shall be recorded daily. ~

D. Cc: trol Red and Control Rod Drive D. Control Rod Drive and Control Rod Drive

.da:n:cr ance

• .Tlaintenance A ruxinre of tw rm-adjacent control.

rods separated by rnre than two control cells in any direction, may te withdrawn fecri the core for the purtose of gr-ferming control rcd and/or control rod drive ruinterunce provided tt.e following co-ditions are satisfied: *

1. The reactor mode switch shall be locked 1. This surveillance requirement is the same '

in the '*re-fuel" position. The re-fucit.:g as given in 4.10.A.

ir.terlock vehich prevents more than one control red from being withdrawn may bc bj;ussed for one of the control rods on * .

v.hich mair.:enance is being performed.

.11 other re-fueling interlocks sitall be operabic.

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r i Ra m : DPR-19 A. Refueling Interlocks excursion or a critical configuration, thus During refueling operations, the reactivity potential of the core is being altered. It B. Core Monitoring is necessary to require certain interlocks and restrict certain refueling procedures such The SRM's are provided to monitor the core

, that there is assurance that inadvertent during periods of station shutdown and to criticality does not occur. guide the operator during refueling operations and st eion startup. Requiring two operable To minimize the possibility of loading fuel SRM's in or adjacent to any core quadrant into a cell containing no control rod, it is where fuel or control rods are being moved required that all control rods are fully assures adequate monitoring of that quadrant inserted when fuel is being loaded into the during such alterations. Rcquiring a minimum of 3 reactor core. This requirement assures that counts per second whenever criticality is possible during refueling the refueling interlocks, ,provides assurance that neutron flux is being at designed, will prevent inadvertent criti- monitored. Criticality is considered to be impossible cality. The core reactivity limitation of if there are no more than two asserrblies in a quadrant Specifications 3.2 limits the core alterations and if these are in locations adjacent to the SP4.

to assure that the resulting core loading In this case only, the SW1 or dunking type detector can be controlled with the reactivity control count rate is permitted to be less than 3 counts system and interlocks at any time during per second.

shutdown or the following operating cycle.

C. Fuel Storage Pool Water Lesel Addition of large amounts of reactivity to the core is prevented by operating procedures, To assure that there is adequate water to which are in turn backed up by refueling shield and cool the irradiated fuel assemblies interlocks on rod withdrawal and movement of stored in the pool, a minimum pool water the refueling platfom. When the mode switch level is established. The minimum water is in the " Refuel" position, interlocks level of 33 feet is established because it

' prevent the refueling platform from being would be a significant change from the normal moved over the core if a control rod is level (37'9") well above a level to assure withdrawn and fuel is on a hoist. Likewise, adequate cooling (just above active fuel) if the refueling platfom is over the core and above the level at which the GSEP action with fuel on a hoist, control rod motion is is initiated (5' uncontrolled loss of level blocked by the interlocks. With the mode with level decreasing) .

switch in the refuel position only one control rod can be withdrawn. D. During certain periods. It is desirable to perform maintenance on two control rods For a new core the dropping of a fuel assembly and/or control rod drives at the same time.

into a vacant fuel location adjacent to a .Ihis specification provides assurance that withdrawn control rod does not result in an

. inadvertent criticality does not. occur

. ~during'such naintenance.

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i Enclosure 2 Dresden Station Unit 3 Proposed Technical Specification Changes Revised Pages: 151 152 155 t

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DPR-25 4.10 SURVEILLANCE REQUl!'C3:! NT 3.10 1.1. SILTING CONDITION FOR OPEllATION 4,10 REFUET.fNG "1 10 11El'I'E1.ING Applicability:

Applicabilitv:

Applies to the periodic testing of those interlocks Applies to fuel handling and core reactivity and i:.struments used during refueling.

limitations. .

Objective:

Objective:

' To verify the operability of ins'rumentation and To assure core reactivity is within capability of interlocks used in refueling.

the control rods and to prevent criticality during refuelir.g.

i Specification:

Specification: i 1

A. Itefueling Interlocks A. Refueling Interlocks 2

Prior to any fuel handling, with t'.e head off The reactor mode switch shall be locked in the reactor vessel. t:ic refueling ir.terlo. ks the "Hefuel" position during core alterations shall be functionally tested. Thev sh ill a!so and the refueling interlocks shall be operable be les.ed at wer?:1c ir.tcreais thereaf:cr "t:1 except as specified in Specifications 3.10.D no longer requiro! ard io!imiing nn:. re;'.dr ar.d 3.10. E. work associated "ti'h the interlocks.

B. Core alonitoring B. Core Stonitoring l Prior to makint: any alter: tio.e, te ti:e core D::rin:; core alterations two Sit 31's shaII be , the SR31's shall be functf<r' ally tested a r:

Th<:reaito r, operable, one in the core quadrant wherc j checked for neutr<r. res~rve.

fuel or can'rol rods are being moved and onc ' the S!!)1's will be checkut daily f ar rcs!-;nse.

in an adjacent quadrant. For an S1131 to be except when the conditions of 3.10.B.2.a considered operable. the following conditions and 3.10.B.2.b are met.

shall be satisfied: .

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DPR-2% I .

3.10 LD"! TING COSDITION FOR OPERATION 4.10 SURVE!LLANCE REQUIRE >lEST ,

1. The SiOI shall be inserted to the ncrrnal operating level. (Use of special moveable. .

dunkin : type detectors claring initial fuel le: ding :nd major core aitcrations in place of n:str..al <letectors are permissible es

' long as the detector is connected ir,to the .

ner:nal SIDI circuit.) ,

2. 'Ihe Sfet or dunking type detector shall have a .. ,,

minfrum of 3 cpg with all rods' fully inserted in the core except when both of the following -

corditions are fulfilled:

' ~

a) !b enre than tuo fuel assemblies are present in the core quadrant associated with the Sres.

b) Wile in core, these fuel assernblies are in locations adjacent to the S'N, C. Fuel Storage Pool Water Level C. Fuel Storage Pool Water Level Whenever irradiated fuel is stored in the fuci Whenever Irradiated fuel is stored in the stora;;c pool, the pool wo.tcr leyel shall be fuct storage ;nol, the pool level shall be maintained ot a level of 33 feet. recorded daily.

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D. Control Red and Control Rod Drive D. Control Rod Drive and Control Rod Drive 31ainter ance , 31aintenance

• A maxinten of two non-adjacent control i rods separated by nore than two control cells in any direction, may te withdrawn frm the core for the purtose of per-a fccming amtrol rod and/or control rod i drive saintenance provided the following

. conditions are satisfied: I

1. The reactor mode switch shall be locked 1. This surveillance requirement is the same '

in the "rc-fuel" position. The re-fueling tts given in 4.10.A.

ir.terlock which prevents more than one control rod from beir.g withdrawn may bc b:.;ussed for one of the control rods on * .*

. t.hich mair.:enance is being performed. ,

/.11 other re-fueling interlocks siiall be upcrabic.

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DpR-25 A. Refueling Interlocks excursion or a critical configuration, thus -

adequate margin is provided.

During refueling operations, the reactivity potential of the core is being altered. It B. Core Monitoring ia necessary to require certain interlocks and restrict certain refueling procedures such The SRM's are provided to monitor the core that there is assurance that inadvertent aring periods of station shutdown and to criticality does not occur, guide the operator during refueling operations and station startup. Requiring two operable To minimize the possibility of loading fuel SRM's in or adjacent to any core quadrant inte a cell containing no control rod, it is where fuel or control rods are being moved required that all control rods are fully assures adequate monitoring of that quadrant inserted when fuel is being loaded into the J during such alterations. Requiring a minimum of 3 reactor core. This requirement assures that counts per second whenever criticality is possible during refueling the refueling interlocks, .provides assurance that neutron flux is being as designed, will prevent inadvertent criti- monitored. Criticality is considered to be impossible

, cality. The core reactivity limitation of if there are no more than two assemblies in a quadrant Specifications 3.2 limits the core alterations and if these are in locations adjacent to the SIN.

to assure that the resulting core loading In this case only, the SRt or dunking type detector

, can be controlled with the reactivity control count rate is permitted to be less than 3 counts system and interlocks at any time during per second.

shutdown or the following operating cycle.

C. Fuel Storage Pool Water Level Addition of large amounts of reactivity t To assure that there is adequate water to the core is prevented by operating procedures, shield and cool the irradiated fuel assemblies which are in turn backed up by refueling

] stored in the pool, a minimum pool water j interlocks on rod withdrac1 and movement of level is established. The minimum water the refueling platfom. When the mode switch level of 33 feet is established because it j is in the " Refuel" position, interlocks would be a significant change from the nomal prevent the refueling platform from being moved over the core if a control rod is level (37'9") well above a level to assure adequate cooling (just above active fuel) withdrawn and fuel is on a hoist. Likewise, and above the level at which the GSEP action if the refueling platform is over the core i with fuel on a hoist, control rod motion is is initiated (5 ' uncontrolled loss of level '

with level decreasing) .

< blocked-by the interlocks. With the mode

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switch in the refuel position only one During certain periods. It is desirable D.

control rod can be withdrawn. to perform maintenance on two control rods For a new core the dropping of a fuel assembly and/or control rod drives at the same time.

This specification provides assurance that i into a vacant fuel location adjacent to a inadvertent criticality does not occur

] withdrawn control rod does not result in an during such maintenance. ,

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I Enclosure 3 Quad Cities Station Unit 1

,/' Proposed Technical Specification Changes Revised Pages: 3.10/4.10-2 t 3.10/4.10-4 i

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OUAD CITIES DPR-29

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b. Iloist overload.

c. High position limitation.

B. Core Monitoring B. Core Monitoring During cure alterations. two SRM's shall be Prior to any alterations to the core, the SRM's , <

operable, one in the core quadrant where fuel shall be functionally tested and checked for j or control rods are being moved and one in an neutron respimse. Thereafter, the SRM's shall adjacent quadrant. For in SRM to be consid- be checked daily for response, except I cred operable, the following conditions shall be when the conditions of 3.10.B.2.a  !

satisfied; and 3.10.3.2.b are met, I. The SRM shall be inserted to the nor-mal operating level (use of special movable, dunking type detectors dur-

• ing initial fuel loading and major core alterations in place of normal detec-tors is permissible as long as the detec-  ;

f  !

tot is connected into the proper circui- ,

i try which contains the required rod blocks).

2. the SIN or dunking type detector shall have a minirrum of 3 cps with all rods fully incerted in the cx>re except when both of the following ,.

corditions are fulfilled: .,

y a) tb rrore than two fuel assmblies are $

present in ther core quadrant acsociated -

with the SW1 b) While in cere, these fuel assmblics are 11 locations E.djacent to the SEN. .',

Q,1 C. Fuel Storage Pool Water Lesel C. Fuel Storage Tool Water ' Level Whenever irradiated fuel is stored in the fuel Whenever irradiated fuel is stored in the fuel storage pool, the pool water level shall be storage pool, the pool level shall be recorded maintained at a level of at ! cast 33 feet. daily.

D. Control Rod and Control Drive Maintenance D. Control Rod and Control Rod Drive A maximum of two nonadjacent control rods

. separated by more than two control cells in any ~j direction may be withdrawn from the core for  !

the purpose of performing control rod and/or }

control rod drive maintenance provided the following conditions are satisfied: l

1. The reactor mode switch shall be I

1. Sufficient control rods shall be with-locked in the Re' fuel position. The re- drawn prior to performing this main- I; fueling interiock which prevents more tenance to demonstrate with a margin j ,

than one control rod from being with- of 0.25% ak that the core can be m; de l drawn may be bypassed for one of the subcritical at any time during the control rods on which maintenance is maintenance with the strongest opera- jl;j being performed. All other refueling ble control rod fully withdrawn and all l3 e

interlocks shall be oper'able. other operable rods fully inserted. ;j

2. Specification 3.3.A.I shall be met or Alternately, if a minimum of eight Il the control rod directional control control rods surrounding each control I!

valves for a minimum of eight control rod out of service for maintenance are *I rods surrounding each drive out of to be fully inserted and have their

]

service for maintenance will be dis- directional control valves electrically  ;

armed electrically and Sumcient mar- disarmed, the 0.25% ak mugin wit! .

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3.10 LIMITING CONDITIONS l'OR OPERATION IIASES.  !

A. During refueling operations. the reactivity potential of the core is being altered. It is neceuary to require '.

certain interh>cks and restrict certain refueling procedures such that there is assurance that inadvertent jl

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criticality does not occur. u To minimize the possibility ofloading fuel into a cell containing no control rod, it is required that all control rods are fully inserted when fuel is being loaded into the reactor core. This requirement assures that during refuchng. the refueling interlocks will prevent inadvertent criticality as designed. The core reactivity limitation ofSpecification 3 2 limits the core alterations to auure that the resulting core loading y can be controlled with the reactivity control system and inicriecks at any time during shutdown or the y 1.

following operatir.g cycle.

i The addition oflarge amounts of reactivity to the core is prevented by operating procedures, which are

.t in turn backed up by refueling interlocks on rod withdrawal and movement of the refueling platform.

When the mode switch is in the Refuel position, interlocks prevent the refuciing platform from being i'

moved over the core if a control rod is withdrawn and fuel is on a hoist.

Likewise, if the refueling platform is over the core with fuel on a hoist, control rod motion is blocked by the interlocks. Wi.h the mode switch in the Refuel position, only one control rod can be withdrawn. i[ '

B. The SRM are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup. Requiring two operable SRM in or adjacent to any core quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations. Regairing a minimtrtt of 3 counts per second whenever criticality l is posible provides assurance that neutron flux is tving monitored. Criticality is 2l 1 considered to be impossible if there are no more than two assemblies in a quadrant and if these ere in 1crations adjacent to the Sr01. In this case only, the .W1 or dunking type detector count tate is permitted to be less than 3 counts per second.

C. To assure that there is adequate water to shield and cool the irradiated fuel assemblies stored in the pool. I a minimum pool water level is established. Th minimum water level of 33 feet is established because i' it would be a significant change from the normal level (37 feet 9 inches) well above a level to'auure adequate cooling (just above active fuel), and above the level at which GSEP action is initiated (5 feet j uncontrolled loss of level with level decreasing). [l n ~

D. During certain periods, it is desirable to perform maintenance on two control rods and/or control rod i drives at the same time. This specification provides assurance that inadvertent criticality does not occur l during such maintenance.  ; i The maintenance is performed with the mode switch'in the Refuel position to provide the refueling interlocks normally available during refueling operations as explained in Part A of these bases. In order to withdraw a second control rod after withdrawal of the f rst rod. it is necessary to bypau the refueling j ,

interlock on the first control rod which prevents more than one control rod from being withdrawn at the i same time.Tt. requirement that an adequate shutdown margin be demonstrated with the control rods i remainir; in service ensures that inadvertent criticality cannot occur during this maintenance. The {

shutdown margin is verified by demonstrating that the core is shut down even if the strongest control rod

• remaining in service is fully withdrawn. Disarming the directional control valves does not inhibit control rod scram capability.

E. The intent of this specification is to permit the unloading of a significant portion of the reactor core for such purposes as inservice inspection requiremems, examination of the core support plate. cie. This specification provides assurance that inadvertent criticality does not occer during such operation.

This operation is performed with the mode switch in the Refuel position to provide the refueling

~

interlocks normally available during refueling as explained in the bases for Specification 3.10.A. In order to withdraw more th: n one control rod, it is necessary to bypass the refueling interlock on each withdrawn' control rod which prevents more than one control rod from being withdrawn at a time. The requirement that the fuel awemblies in the cell controlled by the control rod be removed from the reactor e

Enclosure 4 Quad Cities Station Unit 2 Proposed Technical Specification Changes Revised Pages: 3.10/4.10-2 3.10/4.10-4 3

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q DPR-30 L

'# b. Iloist overlo2 d. I<

c. High pmition limitation. ,

B. Core Monitoring B. . Core Monitoring Prior to any alterations to the core, the SRM's  !

During core alterstions. two SRM's shall be  :

operable, one in the core quadrant where fuel shall be functionally tested and checked for '

or control rods are being moved and one in an neutron response. Thereafter, the SRM's shall adjacent quadrant. For an SRM to be consid- be checked daily for response, except '

I I

cred operabic, the following conditions shall be when the conditions of 3.10.B.2.a satisfied; and 3.10.B.2.b are met. ,,

l. The SRM shall be inserted to the nor- 't ,

mal operating level (use of special movable, dunkir.g type detectors dur- ,

ing initial fuel loading and major core alterations in place of normal detec-tors is permissible as long as the detec- I tor is connected into the proper circui-try which contains the required rod blocks).

2. Toe SIN or dunking type detector shall have a minirrum of 3 eps with all rods fully incerted in the core excrpt when both of the following conditions are fulfilled:

a) !b rore than two fuel assemblics are present in the core quadrant associated  :

with the Stet.

b) while in core, these fuel ascorblics ate in locations adjacent to the s'N.

lU,.! C. Fuel Storage Pool Water leel C. Fuel Storage Pool Water ' Level Whenever irradiated fuel is stored in the fuel Whenever irradiated fuel is stored in the fuel ,

storage pool, the pool water level shall be storage pool, the pool level shall be recorded maintained at a level of at least 33 feet. daily.

D. Control Rod and Control Drise Maintenance D. Control Rod and Control Rod Drise Maintenance A maximum ortwo nonadjacent control rods

. separated by more than two control cells in any direction may be withdrawn from the core for the purpose of performing control rod and/or control rod drive maintenance provided the following conditions are satisfied:

1. The reactor mode switch shall be 1. SufTicient control rods shall be with-locked in the Re' fuel position. The re- drawn prior to performing Inis main-fueling interlock which prever.;s more tenance to demonstrate with a margin than one control rod from being with- of 0.25% ok that the core can be made drawn may be bypassed for one of the subcritical at any time during the control rods on which maintenance is being performed. All other refueling interlocks shall be operable.

maintenance with the strongest opera-ble control rod fully withdrawn and all other operable rods fully inserted.

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2. Specification 3.3.A.1 shall be met. or Alternately, if a minimum of eight  ;

the control rod directional centrol control rods surrounding each control l valves for a minimum of eight control rod oct of service for maintenance are rods surrounding each drive out of to be fully inserted and have their

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service for maintenance will be dis- directional control valves electrically f

i disarrned, the 0.25% Ak margin will armed electrically and sufTicient mar-

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DPR-30

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! e 3.10 LIMITING CONDITIONS FOR OPERATION llASES A. During refueling operations. the reactivity potential of the core is being altered. It is necessary to require I' certain interlocks and restrict certain refueling procedures such that there is assurance that inadvertent j criticality does not occur.

To minimize the possibility ofloading fuel into a cell comaining no control rod, it is required thet all control rods are fully inserted when fuel is being loaded into the reactor core. This requirement assures that during refueling, the refueling interlocks will prevent inadvertent criticality as designed. The core reactivity limitation ofSpecification 3.2 limits the core alterations to assure that the resulting core loading

, can be controlled with the reactivity control system and interlocks at any time during shutdown or the following operating cycle.

The addition oflarge amounts of reactivity to the core is prevented by operating procedures, which are in turn backed up by refueling interlocks on rod withdrawal and movement of the refueling platform.

4 When the mode switch is in the Refuel position, interlocks prevent the refueling platform from being moved over the core if a control rod is withdrawn and fuel is on a hoist.

Likewise, if the refueling platform is over the core with fuel on a hoist, control rod motion is blocked by the interlocks. With the mode switch in the Refuel position, only one control rod can be withdrawn.

B. The SRM are provided to monitor the core during periods of station shutdown and to guide the operator

' during refueling operations and station startup. Requiring two operable SRM in or adjacent to any (ore quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations. Reg,: iring a minimum of 3 counts per second whenever criticality is possible provides assurance that neutron flux is being monitored. Criticality is

'I considered to be iTpossible if there are no more than two assenblies in a quadrant and if these are in locations adjacent to the STO!. In this case only, the SIN or dunking type detector count rate is permitted to be less than 3 counts per second.

j C. To assure that there is adequate water to shield and cool the irradiated fuel assemblies stored in the pool.

a minimum pool water level is established. The minimum water level of 33 feet is established because 1

it would be a significant change from the normal level (37 feet 9 inches), well above a level to assure adequate cooling (just above active fuel), and above the level at which GSEP action is initiated (5 feet uncontrolled loss oflevel with level decreasing).

i j D. During certain periods, it is desirable to perform maintenance on two control rods and/or control rod l drives at the same time. This specification provides assurance that inadvertent criticality does not occur .

j during such maintenance.

The maintenance is performed with the mode switch in the Refuel position to provide the refueling interlocks normally available during refueling operations as explained in Part A of these bases. In order to withdraw a second control rod after withdrawal of the first rod,it is necessary to bypass the refueling j interlock on the first control rod which prevents more than one control rod from being withdrawn at the j same time. The requirement that an adequate shutdown margin be demonstrated with the control rods remaining in service ensures that inadvertent criticality cannot occur during this mainteriance. The shutdown margin is verified by demonstrating that the core is shut down even if the strongest control rod l remaining in service is fully withdrawn. Disarming the directional control valves does not inhibit control tod scram capability.

]

E. The intent of this specification is to permit the unloading of a significant portion of the reactor core for such purposes as inservice inspection requirements, examination of the core support plate, etc. This

- specification provides assurance that inadvertent criticality does not occur during such operation.

~

This operation is performed with the mode switch 'in the Refuel position to provide the refueling interlocks normally available during refueling as explained in the bases for Specification 3.10.A. In order to withdraw more than one control rod, it is necessary to bypes the refueling interlock on each

!' withdrawn' control rod which prevents more than one control rod from being withdrawn at a tirrc. The requirement that the fuel assemblics in the cell controlled by the control rod be removed from the reactor

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