ML20071N615

Proposed Tech Specs Re RCS Flow Rate & Nuclear Enthalpy Rise Hot Channel Factor Measurement

ML20071N615
Person / Time
Site:	McGuire, Mcguire
Issue date:	06/02/1983
From:	DUKE POWER CO.
To:
Shared Package
ML20071N607	List: ML20071N606 ML20071N615
References
TAC-49164, NUDOCS 8306070134
Download: ML20071N615 (7)

Text

Cb Technical Specification 3/4.2.3 - RCS Flowrate and Nucicar Enthalpy Rise Hot Channel Factor Proposed Change Revise Specification 3.2.3.e and Figure 3.2-3 to reduce the measurement uncertainty for total RCS flow.

This results in a decrease in the minimum RCS flow for acceptable operation as shown on Figure 3.2-3.

Revise Specifi-cations 4.2.3.2 and 4.2.3.5 to indicate the measurement methods which provide the reduced uncertainty.

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• W 8306070134 830602 PDR ADOCK 05000369 P

PDR

l POWER DISTRIBUTION LIMITS BASES HEAT FLUX HOT CHANNEL FACTOR, and RCS FLOW RATE AND NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR (Continued) c.

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

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

N F

will be maintained within its limits provided Conditions a. through

d. abgN are maintained.

As noted on Figures 3.2-3 and 3.2-4, RCS flow rate and F rate N acceptable if the measured Fmay be " traded off" against gne another (i.e., a low measured latedDNBRwillnotbebelowthedesknDNBRvalue.is also low) to ensure that the cgicu-The relaxation of F as a function of THERMAL POWER allows changes in the radial power shape for#all permissible rod insertion limits.

gy as calculated in Specification 3.2.3 and used in Figure 3.2-3, accounts analyNswhereFless thag or equal to 1.49.

This value is used in the various accident for F influences parameters -other than DNBR, e.g., peak clad tem-perature, and thN is the maximum "as measured" value allcwed.

R, as defined, 2

allows for the inclusion of a penalty for Rod Bow on DNBR only.

ihus, knowing N

the "as measured" values of F and RCS flow allows for " tradeoffs" in excess ofRequalto1.0forthepurkseofoffsettingtheRodBowDNBRpenalty.

Fuel rod bowing reduces the value of DN8 ratio.

Credit is available to partially offset this reduction.

This credit comes from a generic design margin which total 9.1% when the analysis is perf rmed with the approved N

interim methods.

The penalties applied to F to account for rod bow (Figure 3.2-4)asafunctionofburnupareconsistenhwiththosedescribedin Mr. John F. Stolz's (NRC) letter to T. M. Anderson (Westinghouse) dated April 5,1979, and W 8691, Rev.1 (partial rod bow test data).

When an F measurement is taken, an allowance for both experimental error n

and manufacturYng tolerance must be made.

An allowance of 5% is appropriate for a full core map taken with the Incere Detector Flux Mapping System, and a 3% allowance is appropriate for manufacturing tolerance.

When RCS flow rate and F" are measured, no additional allowances are necessary prior to comparison $ith the limits of Figures 3.2-3 gnd 3.2-4.,

Measurement errors of 1.7% for RCS total flow rate and 4% for F have been l

g allowed for in determination of the design DNBR value.

The measurement error for RCS total flow rate is based upon performing a precision heat balance. and using the result to calibrate the RCS flow rate indicators.

Potential fouling of the feedwater venturi which might not McGUIRE - UNITS 1 and 2 B 3/4 2-4 j

s, POWER DISTRIBUTION LIMITS BASES HEAT FLUX HOT CHANNEL FACTOR, and RCS FLOW RATE AND NUCLEAR ENTHALPY RISE h0T CHANNEL FACTOR (Continued) be detected could bias the result from the precision heat balance in a non-conservative manner.

Therefore, a penalty of 0.1% for undetected fouling of the feedwater venturi is included in Figure 3.2-3.

Any fouling which might bias the RCS flow rate measurement greater than 0.1% can be detected by monitoring and trending various plant performance parameters.

If detected, action shall-be taken before performing subsequent precision heat balance measurements, i.e. either the effect of the fouling shall be quantified and compensated for in the RCS flow rate measurement or the venturi shall be cleaned to eliminate the fouling.

The 12-hour periodic surveillance of indicated RCS flow is sufficient to detect only flow degradation which could lead to operation outside the acceptable region of operation shown on Figure 3.2-3.

McGUIRE - UNITS 1 and 2 B 3/4 2-4a i

l

POWER' DISTRIBUTION LIMITS 3/4.2.3 RCS FLOW RATE AND NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR LIMITING CONDITION FOR OPERATION 3.2.3 The combination of indicated Reactor Coolant System (RCS) total flow rate and R, R2 shall be maintained within the region of allowable operation 1

shown on Figure 3.2-3 for four loop operation:

Where:

F"0" a*

R 1 = 1.49 [1.0 + 0.2 (1.0 - P)]

R y R

2 * [1-RBP(BU)]

THERMAL POWER p

RATED THERMAL POWER F$g = Measured values of F$H obtained by using the movable incore d.

detectors to obtain a power distribution map.

The measured

, values of F$g shall be used to calculate R since Figure 3.2-3 includes penalties for undetected feedwater venturi fouling of 0.1% flow and for measurement uncertainties of 1.7% for flow and 4% for incore measurement of F$H, and e.

RBP (BU) = Rod Bow Penalty as a function of region average burnup as shown in Figure 3.2-4, where a region is defined as those assemblies with the same loading date (reloads) or enrichment (first core).

l APPLICABILITY:

MODE 1.

ACTION:

With the combination of RCS total flow rate and R, R outside the region of y

2 acceptable operation shown on Figure 3.2-3:

a.

.hin 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> either:

1.

Restore the combination of RCS total flow rate and R,y R to within the above limits, or 2

2.

Reduce THERMAL POWER to less than 50% of RATED THERMAL POWER l

and reduce the Power Range Neutron Flux - High Trip Setpoint to l

less than or equal to 55% of RATED THERMAL POWER within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

McGUIRE - UNITS 1 and 2 3/4 2-8

=

POWER' DISTRIBUTION LIMITS 4

ACTION:

(Continued) b.

Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of initially being out:,iJe the above limits, verify through incore flux mapping and RCS total flow rate comparison that the combination of Rg, R within the above limits,2 and RCS total flow rate are restored to or reduce THERMAL POWER to less than 5% of.

RATED THERMAL POWER within the next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

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 a.2. and/or b. above; subsequent POWER OPERATION may proceed provided that the combination of R,, R2 and indicated 1

RCS total flow rate are demonstrated, throogh incore flux mapping and RCS total flow rate comparison, to be within the region of acceptable operation shown on Figure 3.2-3 prior to exceeding the following THERMAL POWER levels:

1.

A nominal 50% of RATED THERMAL POWER, 2.

A nominal 75% of RATED THERMAL POWER, and 3.

Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of attaining greater than or equal to 95% of RATED THERMAL POWER.

SURVEILLANCE REQUIREMENTS 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, R2 shall be 1

determined by process computer readings or digital voltneter measurement to be.

within the region of acceptable operation of Figure 3.2-3.

t

~

a.

Prior to operation above 75% of. RATED THERMAL F0WER after each fuel loading, and b.

At least once per 31 Effective Full Power Days.

4.2.3.3 The indicated RCS total flow rate shall be verified to be within the region of acceptable operation of Figure 3.2-3 at least once per 12 ' hours when the most recently obtained values of R 1 and R,.obtained per Specii'. cation

~2 4.2.3.2, are assumed to exist.

4.2.3.4 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 deter:ained by precision heat balance measurement at least once per 18 months.

McGUIRE - UNITS 1 and 2.

3/4 2-9 n--_--__n_.

~

s PENALTIES OF 0.1% FLOW FOR UNDETECTED FEEDWATER VENTURI FOULING AND FOR MEASUREMENT UNCERTAINTIES Og 1.7% FOR FLOW & 4.0% FOR INCORE MEASUREMENT OF F

ARE 'NCLUDED IN THIS FIGURE.

gg 4s -

7 ACCEPTAELE OPERATION *

' ACCEPTABLE OPERATION I

2 48 "

REGION FOR Rg AND R2 UNACCEPTABLE g,

OPE R ATION REGION

!c

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m d

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(1.0.39.702) g ACCEPTABLE OPERATION REGION FOR 4 90% RTP m

i M=

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UN ACCEPTAB LE y,.

OPERATION REGION

/

3' 34 0.90 0.95 1.00 1.05 1.10 N

R =F 3g/1.49(1.M2(1.0-pil 3

R =R /[1-RBP(Bull 2 g FIGURE 3.2-3 RCS TOTAL FLOWRATE VERSUS R g AND R -FOUR 2

LOOPS IN OPERATION Operation abOve 90% RATED THERMAL POWER may proceed for no more than 48 cumulative hours provided RCS total flow as measured by precision heat balance is greater than 395,850 gpm.

MCGUIRE - UNITS 1 and 2 3/4 2-10

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