Text

Proposed Tech Spec 2.10.2 Re Reactivity Control Sys & Core Physics Parameters Limits
	ML20101C524
Person / Time
Site:	Fort Calhoun
Issue date:	06/05/1992
From:	; OMAHA PUBLIC POWER DISTRICT
To:	;
Shared Package
ML20101C497	List: ML20101C493; ML20101C503; ML20101C524;
References
	NUDOCS 9206090258
	Download: ML20101C524 (14)
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1 2.0 LIMITING CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2. Reactivity Control Systems and Core Physics Parameters Limits (Continued)

ControLElement Assemblics (4) Full 1.cngth CEA Position During Power Oncration All full length (shutdown and regulating) CEA's shall be operable with each CEA of a given group positioned within 12 inches (actual position) of all other CEA's in its group. If one or more of the CEA's is inoperable or misaligned, determine the cause and comply with one of the following:

a. If one or more full length CEA's are inoperable due to: 1) being immovable as a result of excessive friction or mechanical interference, or 2) known to be untrippable, determine that the shutdown margin requirement of Specincation 2.10.2(1)is satisned within I hour and be in at least hot shutdown within 7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months ,

b. With one fulliength CEA inoperable due to causes other than addressed in item

a. above, and inserted beyond the Long Term Steady State Insertion Limits but within its above specified alignment requirements, power operation may continue for up to 7 EFPD's per occurrence with a total accumulated time of

< 14 EFPD per calendaeyear fuel cyclc.

c. With one fulllength CEA inoperable due to causes other than addressed in item

a. above, but within its above specified alignment requirements and either fully withdrawn or above the Long Term Steady State Insertion Limits if in CEA group 4, power operation may continue,

d. With one or more full length CEA's misaligned from any other CEA's in its group by more than 12 inches but less than 18 inches (actual position) within one hour either:

(i) Restore the misaligned CSA(s) to within 12 inches (actual position) of any other CEA's in its own group (realignment shall be made while maintaining the allowable CEA sequen;.e and CEA insertion limits of the Power Dependent Insertion Limits Figure provided in the COLR; or (ii) Declare the CEA's inoperable. Power operation may continue 1,rovic all of the following conditions are met:

1. The power level shall be reduced to .170% of the maximum allowable power level for the existing Reactor Coolant Pump combination within an additional one hour; if negative reactivity insertion is required to reduce power, boration shr!! be used.

2-50a Amendment No. 8,20r32,441 l

9206090258 DR 920605 ADOCK 05000285 PDR

2.0 Llh1LIING CONDITIONS FO't OPERATION 2,10 Reactor Core (Continued) 2.10.2. Reactivitv Control Systems and Core Physics Parameters Limits (Continued)

(5) Non trippable CEA Position During Power Operation All non-trippable CEA's (NTCEA) shall be withdrawn to at least 114 inches (actual position). If one or more NTCEA's becomes misaligned from other NTCEA's by more than 12 inches (actual position) either:

a. Restore the NTCEA to within the specified alignment requirements within one hour, or

b. Be in at least hot shutdown within an additional 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

(6) Shtitdown CEA Insertion Limit During Power Operatio.a All shutdown CEA's shall be withdrawn to at least 114 inches as a condition for reactor criticality, or with one or more shutdown CEA's inserted to more than 114 inches withdrr.,vn, except for surveillance testing, within one hour, either:

a. Withdraw t!.c CEA's to at least 114 ir.ches, or

b. Declare the CEA.'s inoperable and apply Specification 2.10.2(4).

(7) Regulating CEA Insertion Limits During Hot Standby and Power Operation l The regulating CEA groups shall be positioned within the acceptable operating range for regulating rod position of the Power Dependent insertion Limits Figure provided in the COLR except during CEA exerciscs above 114 inches. With all CEA's operable, CEA insertion beyond the Long Term Insertion Limits are is restricted to:

1. 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months per 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months interval,

2. 4 EFPD per 30 EFPD interval, and

3. 14 EFPD per fuel cycle ealemlar-year,

a. When the regulating CEA groups are inserted beyond t... Transient insertion Limits, within two hours, either:

(i) Restore the regulating CEA groups to above the Transient

! Insertion Limits, or (ii) Reduce reactor power to the allowed p"ver of Figure 2-4 which permits continued operation above the iransient Insertion Limit using the existing CEA group position.

1 2-50c Amendment No. Mr109,444 L

2.0 LIMITIjSG CQNDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2. Reactivity Control Systems and Core Physics Parameters 1.imits (Continued)

b. When the regulating CEA groups are inserted beyond the Long Term Insertion Limit for a time interval in excess of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months per 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months interval, operation may proceed deleting ti.a daily restriction, provided either:

(i) Regulating CEA groups are not inserted below the Short Term Insertion Limit, or (ii) Regulating CEA groups are not inserted below the Transient Insertion Limit and rates of power increases initiated when the regulating CEA's are inserted below the Short Term insertion i Limit are less than 5%/ hour,

c. When the regulating CEA groups are inserted below the Long Term Insertion Limit for time intervals in excess of 4 EFPD per 30 EFPD interval and 14 EFPD per fuel cycle calendarpr, either:

(i) Restore the regulating groups to within the Long Term Insertion Limit within two hours, or (ii) Be in hot shutdown within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

(8) CEA Droo Time The individual full length (shutdown and regulating) CEA drop time, from a fully withdrawn position, shall be .12.5 seconds from the time the clutch coil is de-energized until the CEA reaches its 90 percent insertion position with:

a. Ta .;>_.515'F, and

b. All reactor coolant pumps operating.

With the drop time of any full length CEA determined to exceco the above limit, restore the CEA drop time to within the hbove limit prior to proceeding to hot standby or power operation.

(9) Test Exemption

a. CEA Insertion Limits and Misalignment (i) The insertion limits of Specification 2.10.2 may be suspended durirg the performance of physics tests provided:

2-50d Amendment No. M

2.0 LIMITING CONDITION'SJOR OPER4IlON 2.10 Reactor Core (Continued) 2.10.2 Reactivity Control Systems and Core Physics Parameters 1.imits (Continued)

1. The power is restricted to the test power plateau which shall not exceed (85%) of rated power, and

2. The power shall be determined at least once per hour during physics tests.

L 3. The linear heat rate shall be determined to be wi.ain the limits of Specification 2.10.4(1) by monitoring it continuously with the Incore Detector Monitoring System during physics tests above 5% of rated power.

(ii) The alignment requirements of Specification 2.10.2(4) and insertion limits of Specification 2.10.2(7) may be suspended during the performance of physics tests to determine the isothermal temperature coefficient and power coefficient provided:

1. Only the center CEA (CEA 4-1) is misaligned, and

2. The linear heat rate shall be determined to be within the limits of Speci0 cation 2.10.4(1) by mor,itoring it continuously wita the Incore Detector Monitoring System during physics test above 5% of rated power.

(iii) With any of the limits of Specification 2.10.4(1) being exceeded while the requ:rements of Specification 2.10.2(4), (5), (6), and (7) are suspended, either:

1. Reduce power sufficiently to satisfy the requirements of Specification 2.10.4(1), or

2. Be in hot shutdown within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ,

b. Shutdown Margin (i) The shutdown margin required by 2.10.2(1) may be reduced during physics testing at power levels less than 104% of rated power in-the4olkvwing-easen for measurement of.CEA worth and shutdown marg'e_provided that:

L Reactivity equivalent to at least the highest estimated CEA worth is available from the operable CEA groups withdrawn (assuming the most reactive CEA of the grouoj withdrawn is stuck in the fully withdrawn positiont and 2-50e Amendment No. M

2.0 Mh11 TING CONDITIONS FOR Ol'ERATION 2.10 Etattor Cors (Continued) 2.10.2. Reactivity Control Systems and Core Physics Parameters Limits (Continued)

1. The4otal+vailable+nutdown-margitanay4+ reduced-tom

-*Malering-the-meewrement+f-the-shutdown-C-EA-group reaetivitiesrer

2. The40tal availabi' shutdowfanaf@-may4ereduced-to4he wortisf4he-wors tuck CFA's during4heineawrenut+f the-stuck CEA reactivityr-

2. The position of earh trippable CEA required shall be sletermined at least once per 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and.

3. Each CEA not fullyinserted shallinulemonstrated capahic of full insertion when tripped from at Icest them.10fz withdrawn oosition within 7 days prior to reducine the Shutdown Margin to less than the limits of Soccification 2.10.2(1L (ii) If the shutdown margin specified in part (i) above is not available, immediately initiate and continue boration until the requirements of 2.10.2(1) are met.

(iii) The shutdown margin specified in part (i) above shall be verified every 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months shift.

c. Mcderator Temperature Coefficient (i) The moderator temperature coefficient (MTC) requirements of 2.10.2(3) may be suspended during physics tests at less than 10!%

of rated power.

(ii) If p ver exceeds 10% of rated power, either:

1. Reduce power to less than 10-'% of rated power within 15 minutes, or

2. Be in hot shutdown in 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

Basis Shutdown Margin A sufficient shutdown margin ensures that (1) the reccior can be made suberitical from all operati..g conditions, (2) the reactivity transients associated with postulated accident

conditions are controllable withir acceptab!e limits, and (3) the reactor will be maintained sufficiently suberitical to preclude inadvertent criticality in the shutdown condition.

Shutdown margin requirements vary throughout core life as a function of fuel depletion, RCS boron concentration, and RCS T,,,. The most restrictive condition occurs at EOL, '.vith T,,, at no load operating temperature, and is associated with a postulated steana line break accident and resulting uncontrolled RCS cooldown. In the analysis

! of this accident, a minimum shutdown margin of 4.0% Ak/k is iallially adequate to control the reactivity transient. Accordingly, 2-50f Amendment No. 12,43,47,-70

2.0 IJM111EG CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2 Reactivity Control Systems and Core Physics Parameters Limits (Continued) i Control Element Assemblies 1

(4) Eull Length CEA Position During Power Oncration '

All full length (shutdown and regulating) CEA's shall be operable with each CEA of a given group positioned within 12 inches (actual position) of all other CEA's in its group. If one or more of the CEA's is inoperable or misaligned, determine the cause and comply with one of the following:

a. If one or more full length CEA's are inoperable due to: 1) being )

immovable as a result of excessive friction or mechanical interference, or i

2) known to be untrippable, determine that the shutdown margin !

requirement of Specincation 2.10.2(1)is satisfied within I hour and be in at least hot shutdown within 7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months .

b. With one full length CEA inoperable due to causes other than addressed in item a. above, and inserted beyond the Long Term Steady State Insertion Limits but within its above specined alignment requirements, power operation may continue for up to 7 EFPD's per occurrence with a total accumulated time of < 14 EFPD per fuel cycle. l

c. With one full length CEA inoperable due to causes other than addressed in item a. above, but within its above specified alignment requirements and either fully withdrawn or above the Long Term Steady State Insertion l Limits ifin CEA group 4, power operatir:n may continue.

1

d. With one or more full length CEA's misaligned from any other CEA's in its group by more than 12 inches but less than 18 inches (actual position) within one hour either:

(i) Restore the misaligned CEA(s) to within 12 inches (actual position) of any other CEA's in its own group (realignment shall be made while maintaining t'.e allowable CEA sequence and CEA insertion limits of the Power Dependent Insertion Limits Figure provided in the COLR; or (ii) Declare the CEA's inoperable. Power operation may continue provided all of the following conditions are met:

1. The power level shall be reduced to .170% of the maximum allowable power level for the existing Reactor Coolant Pump combination within an additional one hour; if negative reactivity insertion is required to reduce power, boration shall be used.

2-50a Amendment No. 8,20,32,444 j

2.0 LIMITING CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2 Rescilyily Control Sy1tems and Cor.cfbysics Parameters Limits (Continued)

(5) Non-trippable CEA Position During Power Operation All non-trippable CEA's (NTCEA) shall be withdrawn to at least 114 inches (actual position). If one or more NTCEA's becomes misaligned from other NTCEA's by more than 12 inches (actual pasition) cither:

a. Restore the NTCEA to within the specified alignment requirements within one hour, or

b. Be in at least hot shutdown within an additional 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

~

(6) Shutdown CEA Insertion Limit During PowcLQperatifa All shutdown CEA's shall be withdrawn to at least 114 inches as a condition for reactor criticality, or with one or more shutdown CEA's inserted to more than 114 inches withdrawn, except for surveillance testing, within one hour, either:

a. Withdraw the CEA's to at least 114 inches, or

b. Declare the CEA's inoperable and apply Specification 2.10.2(4).

(7) }1ggulating CEA Insertion Limits Durin1LUot Standby and Power OperatiDB The regulating CEA groups shall be positioned within the acceptable operating range for regulating rod position of the Power Dependent insertion Limits Figure provided in the COLR except during CEA exercises above 114 inches. With all CEA's operable, CEA insertion beyond the Long Term insertior Limits is l restricted to: -

1. 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months per 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months interval,

2. / EFPD per 30 EFPD interval, and

3. 14 EFI'D per fuel cycle. l

a. When the regulating CEA groups are inserted beyond the Transient insertion Limits, within two hours, either:

(i) Restore the regulating CEA groups to above the Transient insertion Limits, or (ii) Reduce reactor power to the allowed power of Figure 2-4 which permits continued operation above the Transient insertion Limit using the existing CEA group position.

50c Amendment No. M,409,444

2.0 LIMITlfiG CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2 Reactivity Control Systems and Core Phylles Parameters Limits (Continued)

b. When the regulating CEA groups are inserted beyond the Long Term insertion Limit for a time interval in excess of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months per 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months interval, operation may proceed deleting this daily restriction, provided either:

(i) Regulating CEA groups are not inserted below the Short Term Insertion Limit, or (ii) Regulating CEA groups are not inserted below the Transient Insertion Limit and rates of power increases initiated when the regulating CEA's are inserted below the Short Term Insertion Limit are less than 5%/ hour,

c. When the regulating CEA groups are inserted below the Long Term Insertion Limit for time intervals in excess of 4 EFPD per 30 EFPD interval and 14 EFPD per fuel cycle, either: l (i) Restore the regulating groups to within the Long Term Insertion Limit within two hours, or (ii) Be in hot shutdown within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

(8) CEA Drop Time l

The individual full !cngth (shutdown and regulating) CEA drop time, from a fully withdrawn position, shall be <_2.5 seconds from the time the clutch coil is de-energized until the CEA reaches its 90 percent insertion position with:

, s. Tuu .A515'F, and I h. All reactor coolant pumps operating.

I With the drop time of any full length CEA determined to exceed the above limit, restore the CEA drop time to within the above limit prior to proceeding to hot l standby or power operation.

(9) Test Exemption

a. CEA Insertion Limits and Misalignment (i) The insertion limits of Specification 2.10.2 may be suspended during the performance of physics tests provided:

2-50:1 Amendment No M

3.0 1.1MITING CONDITIONS FOR OPERATION 2.10 Reactor Cors (Continued) 2.10.2 Reactivity Control Systems and Cots _Ehyiics Parameters Limits (Continued)

1. The power is restricted to the test power plateau which shall not exceed (85%) of rated power, and

2. The power shall be determined at least once per hour <

during physics tests.

3. The linear heat rate shall be determined to be within the limits of Specincation 2.10.4(1) by monitoring it l continuously with the incore Detector Monitoring System I during physics tests above 5% of rated power.

(ii) The alignment requirements of Specincation 2.10.2(4) and inscrtion limits of Speci6 cation 2.10.2(7) may be suspended during the performance of physics tests to determine the isothermal ;

temperature coefficient and power coef6clent provided:

I Only the center CEA (CEA 4-1) is misaligned, and 1.

2. The linear heat rate shall be determined to be within the limits of Specincation 2.10.4(1) by monitoring it continuously with the incore Detector Monitoring System during physics test above 5% of rated power.

(iii) With any of the limits of Specification 2.10.4(1) being exceeded while the requirements of Specification 2.10.2(4), (5), (6), and (7) are suspended, either:

1. Reduce power sufficiently to satisfy the requirements of Specificati on 2.10.4(1), or

2. Be in hot shutdown within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ,

b. Shutdown Margin (i) The shutdown margin required by 2.10.2(1) may be reduced during physics testing at power levels less than 10~'% of rated power for measurement of CEA worth and shutdown margin provided that:

1. Reactivity equivalent to at least the highest estimated CEA worth is available from the operable CEA groups withdrawn (assuming the most reactive CEA of the groups withdrawn is stuck in the fully withdrawn position), and -

2-50e Amendment No. M

2.0 L]MITING CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2. Reactivity Control Systems and Core Physics Parameters Limits (Continued)

2. The position of each trippable CEA required shall be determined at least once per 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , and

3. Each CEA not fully inserted shall be demonstrated capable of full insertion when tripped from at least the 50%

withdrawn position within 7 days prior to reducing the Shutdown Mangin to '.ess than the limits of Specification !

2.10.2(1), i I

(ii) If the shutdown margin specified in part (i) above is not available, i immediately initiate and cont.inue boration until the requirements I of 2.10.2(1) are met.

(iii) The shutdown margin specified in part (i) above shall be verified every 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months shift.

c. Moderator Temperature Coefficient (i) The moderator temperature coefficient (MTC) requirements of .

2.10.2(3) may be suspended during physics tests at less than 108% -

of rated power.

(ii) If power exceeds 10 % of rated power, either:

1. Reduce power to less than 10% of rated power within 15 minutes, or

2. Be in hot shutdown in 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

Basil Shutdown Margin A sufficient shutdown margin ensures that (1) the reactor can be made suberitical from all operating conditions, (2) the reactivity transients associated with postulated accident conditions are controllable 'within acceptable limits, and (3) the reactor will be maintained sufficiently suberitical to preclude inadvertent criticality in the shutdown condition.

Shutdown margin requirements vary throughout core life as a function of fuel depletion, RCS boron concentration, and RCS T.,,. The most restrictive condition occurs at EOL, with T ,, at no load operating temperature, and is associated with a postulated steam line break accident and resulting uncontrolled RCS cooldown. In the analysis of this accident, a minimum shutdown margin of 4.0% ak/k is initially adequate to control the reactivity transient. Accordingly, 2-50f Amendment No. 32,43,47,70

4 A,l,,FACHMENT B l

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DliCMiS10N. JUSTIFICATION AND N0 51 Mif1 CANT H EARDS CONSIDERAT10li Description of Amendment Recuest foi CEA InsertioILDuration:

This proposed amendment will change the limitations associated with Regulating CEA insertion limits during hot standby and power operation for Technical Specifications 2.10.2 year" to "14 EFPD per(4)b,fuel 2.10.2(7,),

cycle. andproposed The 2.10.2(7)c. from "14 change EFPD per calendar is conservative with respect to limits on control rod insertion times and consistent with OPPD's operation with minimized rod insertion times. The existing specification originated in a timeframe in which Fort Calhoun Station operated on annual fuel cycles. With the implementation of 18 month fuel cycles, it is appropriate to revise Specifications 2.10.2 4 cycle" rather than " calendar (ye)b, ar."2.10.2(7) and 2.10.2(7)c. to reference " fuel Basis for No Sianificant Hazards Determination The proposed amendment does not involve a significant hazards consideration because the operation of Fort Calhoun Station in accordance with this amendment would not:

(1) Involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed amendment changes the CEA long term insertion limits in the third (or longest time interval category from "14 EFPD per calendar year" to *14 EFPD per fuel cycle.)'

Since a fuel cycle is greater than a calendar year, the proposed changes are more conservative. Evaluation of the impact of CEA insertions on the fuel residing in the core for a given fuel cycle is also more appropriate than evaluating the insertions on a calendar year basis, which may impact two fuel cycles.

(2) Create the possibility of a new or different kind of accident. It has been determined that a new or different type of accident is not created because no new or different modes of operation result from this change.

(3) Involve a significant reduction in the margin of safety. The CEA insertion duration limits proposed by this change are more conservative than the current Technical Specifications. Therefore, the margin of safety remains unchanged.

Based on the above considerations, it is OPPD's position that this proposed amendment does not involve a significant hazards consideration as defined by 10 CFR 50.92.

?

I

Descriotion of Am' %ent Reouest for Shutdown Marcin:

This proposed amendm, lodifies Technical Specification 2.10.2(9)b(i) to achieve as contained in consistency NUREG 0212 with the h Standard Revision 2. Specifically, Technical Specifications the change defines(STS) exce)tions to Technical for shutdown margin requirements dur'ng physics testing Specification for determining CEA 2.'O.2(1) wort h and shutdown margin at less than 10"% of rated power.

9)b(i)1 have been revised to Technical be consistent Specifications with CE Standard 2.10.2(9)b(1)

TS 3.10.1.and 2.10.2(fications Speci 2.10.2(9)bli)2 and TS Surved1.an)ces 4.10.1.1 and 4.10.1.2.2.10.2(9?bji Fort Calhoun 3 aredoes being notrevised /added, have part respectively, to incorpora length CEA's therefore the wording of 2.10.2(9)b(i)2 has been revised to reflect this difference from the CE Standard. It is proposed that 2.10.2 9)b(i)2 be revised to require demonstration of insertion within 7 days prio(r to reducing the shutdown margin instead of the 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months stated in CE Standard TS. This change is consistent with draft NUREG-1366.

The proposed revision tothe Technical Specification i) adds 2.10.2(9)b(ion wordin g to 3/4.10.1.

achieve consistency with Standard Technical Specificat The objective of the proposed change is to permit full measurement of the sequential CEA Regulating Group worth. The current Technical Specifications do not allow this complete measurement to be performed because the Specification 2.10.2(1) required shutdown margin of 4.0%6k/k (includin an allowance for the most limiting stuck CEA the last half of Regulating Group 1 insertion (w)ith Groups 4is 3 lost during approximate 1 fully inserted . The current 1 allow,sand 2 alread to 2.0%6k/k pro)vided shutdown a reduction Specification 2.10.2(9)b(i)ing reactivities are be measured, but does not permit deviation from group 4.0%ak /k for total regulating group measurements. The proposed change will allow

<~ the sh'adown margin to be reduced to the highest estimated CEA worm available from operable CEA groups. Although these pro)osed changes allow a less conservative shutdown margin (during part of Group '. insertion for sequential CEA Regulating Group measurementj than the existing Technical Specifications, the overall impact remains acceptable because a sufficient shutdown margin 4 defined in both the existing Specification 2.10.2(9)b(1)2 and STS 3/4.10.1)(as is maintained at all times.

Technical Specification 2.10.2(9)b(i has also been revised to provide clarification during measurement of CE)A worths that an allowance for the most being stuck should be assumed when reactive CEA calculating (of themargin.

shutdown groups withdrawn) Technical Specification 2.10.2(9)b(ii), which is unchanged, remains consistent with the STS 3/4.10.1 ACTIONS.

2

1 Basis for No Sianificant Hazards Determination:

The proposed amendment does not involve a significant hazards consideration l because the operation of Fort Calhoun Station in accordance with this amendment i would not:

1) Involve a significant increase in the probability or consequences of an occident previously evaluated. The preposed changes result in a consistency between the fort Calhoun Station Technical Specifications and :

the NUREG 0212 Revision 2 CE Standard Technical Specifications for the STS !

3/4.10.1 exception on-required shutdown margin during measurement of CEA worths. Maintaining an available shutdown margin equivalent to at least the highest-estimated CEA worth during CEA worth measurement ensures the reactor can be adequately shut down if the need arises. Thus proposed change establishes a consistency with the STS and doe,s the not significantly increase the probability or consequences of a previously evaluated accident,

2) Create the postibility of a new or different kind of accident from any accident previously evaluated. It has been determined that a new or different type of accident is not created because no new or different modes of cperation are proposed for the plant. Maintenance of an adequate available shutdown margin, defined as the reactivity equivalent to the highest estimated CEA worth, prevents the possibility of a new or different kind of accident.

3) Involve a significant reduction in a margin of safety. The available shutdown margin is allowed to be reduced for CEA measurements which confirm core design and further insure shutdown margin during Mode 1 operations. The brief time period the shutdown margin is reduced is deemed acceptable as confirmed by the current allowed reduction for shutdown CEA worth measurements and inclusion in the CE Standard Technical Specifications. Therefore, a significant reduction in a margin of safety is not involved.

Based on the above considerations, it is OPPD's position that this pro]osed amendment does not involve a significant hazards consideration as defined by 10 CFR 50.92.

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ML20101C524

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