Text

Proposed Changes to Tech Specs Allowing Cycle 4 Operation W/Exxon Fuel at Reactor Thermal Power Level of 3,411 Mwt
	ML17320A249
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Site:	Cook
Issue date:	12/09/1982
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8212170188 821209 PDR ADOCK 05000316 P

PDR Attachment No.

1 to AEP:HRC:0637G Donald C.Cook Nuclear Plant, Unit No.

2 Description of Unit 2 Cycle 4 Technical Specification Change Requests

I>>

4 C,

The allowable peaking factor, F, in ENC supplied fuel has been finalized as 2.04 and in existing Westinghouse fuel as 1.97.

The proposed T/S have been updated to reflect an F of 2.04, and 1.97 Q

for ENC and Westinghouse supplied fuel respectively.

T/S Pa e No.

Reason for U date 3/4 2-5 3/4 2>>6 3/4 2-7 3/4 2-8 3/4 2-8(a) 3/4 2-8(b) 3/4 2-9, 3/4 2-10

'3/4 2-11, 3/4 2-12 3/4 2-17 3/4 2-18 3/4 2-19 8 2-2

'8 3/4 2-1 S 3/4 2-2 E 3/4 2-4 F

= 2.04 ENC fuel F

= 1.97 Westinghouse fuel Q

Q F

2.04

= ENC fuel F

= 1.97 = Westinghouse fuel Q

F

= 2.04 ENC fuel F

1.97 Westinghouse fuel Q

Q Identifies Figure 3.2-,2 to be applicable for'Westinghouse fuel K(Z) curve for ENC fuel page renumbering changed from 3/4 2-8(a)

Incorporates the F< H limit for ENC fuel in the

'-'R" equation and changes the F>

value for Westinghouse fuel:

.Figure number 3.2-3 has been changed to 3.2-4 and 3.2-4 has been changed to 3.2-5.

F

= 2.04 ENC fuel F

1.97 Westinghouse fuel Q

F

= 2.04

. ENC fuel F

= 1.97 - Westinghouse fuel No new information presented pagination page (Action item b. has been moved from 3/4 2-18 to 3/4 2-19).

Separately define limitation on F for N

ENC and Westinghouse fuel F

= 2.04 ENC fuel H

= 1.49 ENC fuel F

= 1.97 Westinghouse fuel F>H 1.48 Westinghouse fuel No new information presented, pagination page Referenced figures renumbered

Attachment No.

2 to AEP:NRC:06379 Donald C. Cook Nuclear Plant, Unit No.

2 Revised Technical Specification Pages

0

POWER DISTRIBUTION LIMITS HEAT FLUX HOT CHANNEL FACTOR -

F Z)

LIMITING CONDITION FOR OPERATION 3.2.2 F (Z) shall be limited by the following relationships:

Westin house Fuel Exxon Nuclear Co. Fuel Fq(Z) < ~1.97 fK(Z)j FQ(Z) < L3.94] t;K(Z)]

F()(Z) < ~2.04 fK(Z)3 p

FQ(Z)

I4.OB]

[K(Z)]

p

> 0.5 p

< 0.5 THERMAL POWER

~MAL WEII and K(Z} is the function obtained from Figure 3.2-2 for Westing-house fuel and Figure 3.2-2(a) for Exxon Nuclear.Company fuel.

APPLICABILITY:

MODE 1

ACT'(GN:

With FQ(Z) exceeding its limit:

a.

Comply with either of the following ACTIONS:

II 1.

Reduce THERMAL POWER at least lX for each lX FQ(Z) exceeds the limit within 15 minutes and similiarly reduce the Power Range Neutron Flux-High Trip Setpoints within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ; POWER OPERATION may proceed for up to a total of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ; subsequent POWER OPERATION may proceed provided the Overpower AT Trip Setpoints have been reduced at least 15 for each 1~ FQ(Z) exceeds the limit.

The Overpower (A)T Trip Setpoint reduction shall be performed with the reactor in at least HOT STANDBY.

2.

Reduce THERMAL POWER as necessary to meet the limits of Specification 3.2.6 using the APDMS with the latest incore map and updated R.

b.

Identify and correct the cause of the out of limit condition prior to increasing THERMAL POWER above the reduced limit required by a, above; THERMAL POWER may then be increased provided F (Z} is demonstrated through incore mapping to be within its limit.

D.

C.

COOK>> UNIT 2 3/4 2-5 AMENDMENT NO.

PONER DISTRIBUTION LIMITS SURVEILLANCE RE UIREMENTS 4.2.2.1 4.2.2.2 a.

b.

c ~

The provisions of Specification 4.0.4 are not applicable.

F~(Z) shall be determined to be within its -limit by:

Using the movable incore detectors to obtain a power distribution map at any THERMAL POWER greater than 5Ã of RATED THERMAL POWER.

Increasing the measured F (Z) component of the power distribution map by 3X to account for manufacturing toler ances and further inci easing the value by BX to account forMmeasurement uncertainties.

This product defined is Fq(Z).

Satisfying the following relationships at the time of the target flux determination.

Westin house Fuel FO(Z) <

L p 3 (+q~ l FO(z) < L'3.gal

[+q z I where Exxon Nuclear Co.

Fuel FO(z) <

L' p"] (-vVVz)

F<(Z) < ly.o8] (vVY p >.5 p (.5 F~(Z) is the measured total peaking as a function of core M

height.

V(Z) is the function defined in Figure 3.2-3 which corresponds to the target

band, K(Z) is defined in Figure 3.2-2 for Westinghouse fuel and Figure 3.2-2(a) for Exxon Nuclear Co. fuel, P is the fraction of RATED THERMAL POWER.

d..

Measuring F~(Z) in conjunction with the target flux difference and target band determination, according to the following schedule:

1.

Upon achieving equi librium conditions after exceeding by 10K or more of RATED THERMAL POWER, the THERMAL POWER at which F~(Z) was last determined*,

or 2.

At least once per 31 effective full power days, whichever occurs first.

During power escalation at the beginning of each cycle, the design target may be used until a power level for extended operation has been achieved.

0.

C.

COOK - UNIT 2 3/4 2-6 AMENDMENT NO.

0-0

POWER QISTRIBUT ON LIMITS SURVEILLANCE RE UIREMENTS e.

With successive measurements indicating an increase in peak pin power, F>>, with exposure, either of the. following additional actions shaN be taken.

2.

F- (Z) shall be increased by 2X over that specified in 4.2.2.2.c, or F~(Z) shall be measured and a target axial flux difference M

reestablished at least once per 7 effective full power days until 2 successive maps indicate that the peak pin

power, F<H, is not increasing.

f.

With the relationship specified in 4.2.2.2.c not being satisfied either of 'the following actions shall be taken.

1.

Place the core in an equilibrium condition where the limit in 4.2.2.2.c is satisfied and remeasure the target axial flux difference.

2.

Comply with the requirements of Specification 3.2.2 for F (Z) exceeding its limit by the maximum percent calculated with the following expressions with V(Z) corresponding to the target band and P

>.5:

F"(Z) x V(Z) max. over Z of

-1

. tK(Z)3 x 100 Westinghouse Fuel t

F"(Z) x V(Z) max. over Z of

-1 x [K(Z)]

x 100 Exxon Nuclear Company Fuel g.

4.2.2.3 The limits specified in 4.2.2.2.c and 4.2.2.2.f above are not applicable in the following core plane regions:

1.

Lower core region 0 to 10K inclusive.

2.

Upper core region 90K to 100% inclusive.

When F~(Z) is measured for reasons other than meeting the requirements of Specification 4.2.2.2, an overall measured F~(Z) shall be obtained from a power distribution map-and increased by 3A to account for manufacturing tolerances and further increased by SX to account for measurement uncertainty.

Q.

C.

COOK - UNIT 2 3/4 2-7 AMENQMENT NO.

1.2 n

CD CD 1.0 (6.0, 1.0)

(11.37,0.933) 0.8 LLI 0.6 CD 12.0 0.7S4) 0.4 0.2 rn C) rn 0.

0 6

8 10 CORE HEIGHT (FT)~

12 FIGURE 3.2-2

0. C.

COOK UNIT 2, K(Z)-NORWLIZEO Fq(Z)

AS A FUNCTION OF CORE HEIGHT FOR MESTINGHOUSE FUEL

1.2 1.0 (6.0, 1.0) 11.25 0 936) 0.8 0.6 Cg C)

(12.0, 0.731) 0.4 0.2 0.0 0

12 10 2

4 6

8 CORE HEIGHT (FT)

FIGURE 3.2-2(a) 0.

C.

COOK UNIT 2, K(Z)

NORMALIZED Fo (Z) AS A FUNCTION OF CORE HEIGHT fOR EXXON NUCLEAR CO.

FUEL

I I

I ~

t 1.14 1.12

~ ~

I

~

I I

+5~ Target;Band (9.25, 1.11) 11.25,1.I2 1.10

~ +3~ TargetBand I

I

~

> I

)

J

~

IP (

I I' I ~

~

I I

~

I I

I 1.08 1.06 I

I,'

I I

0

~

I I

I

'.04 1.02 1.00 0

I

(

I I

~

I 4

6 8

Axial Height (feet) 10 12 Figure 3.2-3 V(Z) As A Function of Core Height D.

C.

COOK - Unit 2 3/4 2-8(b )

AMENDMENT NQ.

POWER DISTRIBUTION LIMITS RCS FLOW RATE AND R

LIMITING CONDITION FOR OPERATION 3.2.3 The combination of indicated Reactor Coolant System (RCS) total flow rate and R shall be maintained within the region of allowable operation shown on Figures 3.2-4 and 3.2-5 for 4 and 3 loop operation, respectively.

Where:

a.

R=

Westinghouse Fuel N

F~H

+

~

P Exxon Nuclear Company Fuel NF~

.49

.0 +

.2

.0 -

P b.

P

=

THERMAL POWER 0 TH AL PGWE APPLICABILITY:

" MODE 1.

ACTION:

With the combination of RCS total flow rate and R outside the region of acceptable operation shown on Figure 3.2-4 or 3.2-5 (as applicable):

a.

Within 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s:

l.

Either restore the combination of RCS total flow rate and R to within the above limits, or 2.

Reduce THERMA POWER to less than 50K of RATED THERMAL POWER and reduce the, Power Range Neutron Flux - High trip setpoint to

<55K of RATED THERMAL POWER within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

b.

Within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of initially being outside the above limits, verify through incore flux mapping and RCS total flow rate comparison that the combination of R and RCS total flow rate are restored to within the above limits, or reduce THERMAL POWER to less than 5X of RATED THERMAL POWER within the next 2

hours.

c.

Identify and correct the cause of the out-of-limit condition prior to increasing THERMAL POWER above the reduced THERMAL POWER Limit required by ACTION items a.2 and/or b above; subsequent POWER OPERATION may proceed provided that the combination of R and indicated RCS total flow rate are demonstrated, through incore flux mapping and RCS total 0.

C.

COOK - UNIT 2 3/4 2-9 AMENDMENT NO.

POWER DISTRIBUTION LIMITS ACTION:

(Continued) flow rate comparison, to be within the region of acceptable operation shown on Figure 3.2-4 or 3.2-5 (as applicable) prior to exceeding the following THERMAL POWER levels:

l.

A nominal 50K of RATED THERMAL POWER, 2.

3.

A nominal 75K of RATED THERMAL POWER, and Within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of attaining

> 95Ã of RATED THERMAL POWER.

SURVEILLANCE RE UIREMENTS 4.2.3.1 The provisions of Specification 4.0.4 are not applicable.

4.2.3.2 The combination of indicated RCS total flow rate and R shall be determined to be within the region of acceptable operation of Figure 3.2-4 or 3.2-5 (as applicable):

a.

Prior to operation above 75K of RATED THERMAL POWER after each fuel loading, and b.

At least once per 31 Effective Full Power Days.

Where:

Westinghouse Fuel NF~

Exxon Nuclear Company Fuel NF~

+ 0.

.0-P

.0 + 0.2

.0 -

P F<H

= Measured values of F~ obtained by using the movable N

N incore detectors to obtain a power distribution map.

The measured values of F> shall be used to calculate R since N

- Figures 3.2<

and 3.2-5 include measurement uncertainties of 3.5>> for flow and 45 for iscore measurement of F>.

4.2.3.3 The RCS total flow rate indicators shall be subjected to a

CHANNEL CALIBRATION at least -once per 18 months.

4.2.3.4 The RCS total flow rate shall be determined by measurement at least once per 18 months.

D.

C.

COOK - UNIT 2 3/4 2-10 AMENDMENT NO.

48 Measurement Uncertainties of 3.SX for Flow and 4X for Incore Measurement of F<NH are Included in

.this Figure.

44 (1.074,43.9) 42 ACCEPTABLE OPERATION REGION 38 UNACCEPTABLE OPERATION REG10M (1. 0,37. 5) 36 (0.98,36.64) 34 0.90 1.10 0.94 0.98 1.02 1.06 R=FgH/1.48[1.0+0.2(1.0-P) ] WESTINGHOUSE FUEL R=F~H/1.49[1.0+0.2(1..0-P)]

EXXON NUCLEAR CO.

FUEL 1.14 FIGURE 3.2-4 RCS TOTAL FLOWRATE VERSUS R - FOUR LOOPS IN OPERATION 0.

C.

COOK UNIT 2 3/4 2-11 Amendment No.

38 36 Measurement Uncertainties of 3.5X for Flow and 4X for Incore Measurement of F<>H are Included in this Figure.

I CL CO 32 ACCEPTABLE OPERATION

REGION, (1.074,31.7)

CD 30 CD I

28 UNACCEPTABLE OPERATION REGION (1.0,27.13) 26 (0.971,26.15 0.90 0.94 0.98 1.02 1.06 1.10 R=F~H/1.48I.1.0+0.2(1.0-P)]

WESTINGHOUSE FUEL R=F~H/1.49[1.0+0.2(l.O-P)]

EXXON NUCLEAR CQ.

FUEL FIGURE 3.2-5 RCS TOTAL FLOWRATE YERSUS R - THREE LOOPS IN OPERATION 1.14 0.

C.

COOK UNIT 2 3/4 2-12 Amendment No.

POWER DISTRIBUTION LIMITS AXIAL POWER DISTRIBUTION LIMITING CONDITION FOR OPERATION 3.2.6 The axial power distribution shall be limited by the following relationship:

Mestinghouse Fuel Exxon Nuclear Company Fuel F (Z)g 1.97 K Z)

[F.(Z)]

=

2.04 K(Z (K )(PL)(1.03)(1 + aj)(1.07) j s

(R.)(PL)(1.03)(l + ~.)(1.07)

Mhere:

a.

F>(Z) is the normalized axial power distribution from thimble j at core elevation Z.

b.

C.

PL is the fraction of RATED THERMAL POWER.

K(Z) is the function obtained from Figure 3.2-2 for Westinghouse Fuel and Figure 3.2-2(a) for Exxon Nuclear Company Fuel for a given core height location.

d.

R., for thimble j,'s determined from at least n=6 in-core flux maps 'covering the full configuration of permissible rod patterns above lOOX or APL (whichever is less) of-RATED THERMAL POWER in accordance with:

n Where:

FNeas Qi 1j max and fF,-.(Z)j

is the maximum value of the 'normalized axial distribution at elevation Z from thimble j in map i which has a

measured peaking factor without uncertainties or densification allowance of F

0.

C.

COOK - UNIT 2 3/4 2-17 AMENDMENT NO.

POWER DISTRIBUTION LIMITS LIMITING CONDITIONS FOR OPERATION Continued a. is the standard deviation associated with thimble j, expressed J

as a fraction or percentage of R.,

and is derived from n flux maps from the relationship below, or

.02, (2X) whichever is greater.

a

~

=

J L 1.

2 1/2 nr 1=

'The factor 1.07 is comprised of. 1,02 and 1.05 to account for the axial power distribution instrumentation accuracy and the measure-ment uncertainty associated with F~ using the movable detecto~

system respectively.

The factor 1.03 is the engineering uncertainty factor.

APPLICABILITY: Mode 1 above the minimum percent of RATED THERMAL POWER indicated Kitch t ip APL = min over Z of

100K, 1 97 K Z) 7(

xv APL = min over Z of 100K Me'stinghouse Fuel Exxon Nuclear Company Fuel where F~(Z) is the measured F~(Z), including a 3X manufacturing tolerance uncertainty and a 5X measurement uncertainty, at the time of target flux determination from a power distribution map using the movable incore detector s.

V(Z) is the function defined in Figure 3.2-3 which corresponds to the target band.

The above limit is not applicable in the following core plane regions.

1)

Lower core region OX to 10K inclusive.

2)

Upper core region 90$ to 100K inclusive.

ACTION:

a.

With a F.(Z) factor exceeding t'.F.(Z)jS by

<4 percent, reduce THERMAL l)OHER one percent for every percent by which th P.(Z) factor exceeds its limit within 15 minutes and within the next two hours either reduce the F.(Z) factor to within its limit or reduce THERMAl. POHER to AP( or less of RATED THERMAL POHER.

e APDM may be out of service when surveillance for determining power distribution maps is being performed.

D.

C.

COOK - UNIT 2 3/4 2-18 AMENDMENT NO.

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SAFETY LIMITS BASES The curves are based on a nuclear enthalpy rise hot channel factor, F

, of 1.49 and h reference cosine with a peak of 1.)5 for axial power sNpe.

An allowance is included for an increase in FaH at reduced power based on the expression:

F>H = 1.48 Ll + 0.2 (1-P) j (Westinghouse Fuel)

N F>H = 1.49 t.1+ 0.2 (1-P}]

(Exxon Nuclear Company Fuel)

N where P is the fraction of RATED THERMAL POWER.

These limiting heat flux conditions are higher than those calculated for the range of all control rods fully withdrawn to the maximum allow-able control rod insertion assuming the axial power imbalance is within the limits of the f (hl) function of the Overtemperature trip.

When the axial power imbalance is not within the tolerance, the axial power imbalance effect on the Overtemperature hT trips will reduce the set-points to provide protection consistent with core safety limits.

2.1.2 REACTOR COOLANT SYSTEM PRESSURE

'he-restriction of this Safety Limit protects the integrity of the Reactor Coolant System from overpressurization and thereby prevents the release of radionuclides contained in the reactor coolant from reaching the containment atmosphere.

The reactor pressure vessel and pressurizer are designed to Section III of the ASME Code for Nuclear Power Plant which permits a maximum transient pressure of llOX (2735 psig) of design pressure.

The Reactor Coolant System piping,:valves and fittings, are designed to ANSI 8 31.1 1967 Edition, which permits a maximum transient pressure of 120K (2985 psig) of component design pressure.

The Safety Limit of 2735 psig is therefore consistent with the design criteria and associated code requirements.

The entire Reactor Coolant System is hydrotested at 3107 psig, 125%

of design pressure, to demonstrate integrity prior to initial operation.

O.

C.

Coo~ - UNIT 2 S 2-2 AMENDMENT NO.

3/4.2 POWER DISTRIBUTION LIMITS BASES The specifications of this section provide assurance of fuel integrity during Condition I (Normal Operation) and II (Incidents of Moderate Frequency) events by:

(a) maintaining the calculated DNBR in the core at or above design during normal operation and in short term transients, and (b) limiting the fission gas release, fuel pellet temperature and cladding mechanical properties to within assumed design criteria.

In addition, limiting the peak linear power density during Condition I events provides assurance that the initial conditions assumed for the LOCA analyses are met and the ECCS acceptance criteria limit of 2200oF is not exceeded.

.The definitions of certain hot channel and peaking factors as used in these s pec ificat ions are as fo 1 1 ows:

F~(Z)

Heat Flux Hot Channel Factor, is defined as the maximum local heat flux on the surface of a fuel rod at core elevation Z divided by the average fuel rod heat flux, allowing for manufacturing tolerances on fuel pellets and rods.

F>H Nuclear Enthalpy Rise Hot Channel Factor, is defined as the ratio of the integral of linear power along the rod with,the highest integrated power to the average rod power.

The limits on F~(Z) and F>

for Westinghouse supplied fuel at a core N

average power of 3411 NWt are 1.II7 and 1.48, respectively, which assure con-sistency with the allowable heat generation rates developed. for a core average thermal power of 3391 MWt.

The limits on F (Z) and FqH for ENC supplied fuel have been established for a'core thermal poler of 34234NWt and are.2.04 and 1.49, respectively.

3/4.2.1 AXIAL FLUX DIFFERENCE (AFD)

The limits on AXIAL FLUX DIFFERENCE assure that the Fq(Z) upper bound envelope is not exceeded during either normal operation or in the event of xenon redistribution following power changes.

The F {2) upper bound envelope is 1.97 times the average fuel rod heat flux for Wes inghouse supplied fuel and 2.04 times the average fuel rod heat flux for Exxon Nuclear Company supplied fuel.

Target flux'ifference is determined at equilibrium xenon conditions.

The full length rods may be positioned within the core in accordance with their respective insertion limits and should be inserted near their normal position for steady state operation at high power levels.

The value of the D.

C.

COOK UNIT 2 8 3/4 2-1 AMENDMENT NO.

POWER DISTRIBUTION LIMITS BASE target flux difference obtained under these conditions divided by the fraction of RATED THERMAL POWER is the target flux difference at RATED THERMAL POWER for the associated core burnup conditions.

Target flux differences for other THERMAL POWER levels are obtained by multiplying the RATED THERMAL POWER value by the appropriate fractional THERMAL POWER level.

The periodic updating of the target flux difference value is necessary to reflect core bur nup consi-derations.

Although it is intended that the plant will be operated with the AXIAl FLUX DIFFERENCE within the target band about the target flux difference, during rapid plant THERMAL POWER reductions, control rod motion will cause the AFD to deviate outside of the target band at reduced THERMAL POWER levels.

This deviation will not affect the xenon redistribution sufficiently to change the envelope of peaking factors which may be reached on a

subsequent return to RATED THERMAL POWER (with the AFD within the target band) provided the time duration of the deviation is limited.

Accordingly, a

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months penalty deviation limit cumulative during the previous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is provided for operation outside of the target band but within the limits of Figure 3.2-1 while at THERMAL POWER levels above 5(5 of RATED THERMAL POWER.

For THERMAL POWER-levels between 15% and 505 of RATED THERMAL POWER, deviations of the AFD outside of the target band are less significant.

The penalty of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months actual time reflects this reduced significance.

Provisions for monitoring the AFD on an automatic basis are derived from the plant process computer through the AFD Monitor Alarm.

The computer determines the one minute average of each of the OPERABLE excore detector outputs and provides an alarm message if the AFD for at least 2 of 4 or 2

of 3 OPERABLE excore channels are outside the target band and the THERMAL POWER is greater than 90K or 0.9 x APL of RATED THERMAL POWER (whichever is less).

During operation at THERMAL POWER levels between 50K and 90K or 0.9 x APL of RATED THERMAL POWER (whichever is -less) and between 15K and 50% RATED THERMAL POWER, the computer outputs an alarm message when the penalty deviation accumulates beyond the limits of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , respectively.

~

Figure B 3/4 2-1 shows a typical monthly target band.

The basis and methodology for establishing these limits is presented in topical report XN-NF-77-57, "Exxon Nuclear Power Distribution Control for PWRs - Phase II" and Supplements 1 and 2 to that report.

0.

C.

COOK - UNIT 2 8 3/4 2-2 AMENDMENT NO.

POWER DISTRIBUTION LIMITS BASES 3/4.2.2 and 3/4.2.3 HEAT FLUX HOT CHANNEL FACTOR, RCS FLOWRATE AND NUCLEAR L

H NN L The limits on heat flux'hot channel factor,.RCS flowrate, and nuclear enthalpy rise hot channel factor ensure that I) the design limits on peak local power density and minimum ONBR are not exceeded and 2) in the even) of a LOCA the peak fuel clad temperature will not exceed the 2200 F

ECCS acceptance criteria limit.

Each of these is measurable but will normally only be determined periodically as specified in Specifications 4.2.2 and 4.2.3.

This periodic surveillance is sufficient to ensure that the limits are maintained provided:

a.

Control rods in a single group move together with no individual rod insertion differing by more than

+ 12 steps from the group demand position.

b.

Control rod groups are sequenced with overlapping groups as described in Specification 3.1.3.6.

c.

The control rod insertion limits of Specifications 3.1.3.5 and 3.1.3.6 are maintained.

d.

The axial power distribution, expressed in terms of AXIAL FLUX DIFFERENCE, is maintained within the limits.

F~H will be maintained within its limits provided conditions a.

through d.

above are maintained.

As noted on Figures 3.2-4 and 3.2-5, RCS flow rate and F<

may be "traded off" against one anot)er (i.e.,

a low measured RCS flot rate is acceptable if the measured fa< is also low) to ensure that the calculated ONHR will not be below th'e design ONBR value.

The relaxation of Pa.

as a function of TNERNAI POWER allows changes in the radial power shape fo all permissible rod insertion limits.

When an F

measurement is taken, both experimental error and man-ufacturing tolIIrance must be allowed for.

5% is the appropriate allowance for a full,core map taken with the incore detector flux mapping system and 3X is the appropriate allowance for manufacturing tolerance.

When RCS flow rate and FgH are measured, no additional allowances N

.are necessary prior to comparison with the limits of Figures 3.2-4 and 3<2-5.

Measurement errors of 3.5X for RCS flow total f1ow rate and 4X for F~H have been allowed for in determination of the design DNBR va'lue.

0.

C.

COOK UNIT 2 B3/4 2-4 AMENDMENT NO.

ML17320A249

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