ML17349A796

Nonproprietary Addendum 1 to Thimble Reduction Study for Turkey Point Units 3 & 4.

ML17349A796
Person / Time
Site:	Turkey Point
Issue date:	04/12/1993
From:	Savage C WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
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ML17349A792	List: ML17349A791 ML17349A793 ML17349A794 ML17349A795 ML17349A796
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Wesunghousc Class 3 Thimble Reduction Study for Turkey Point Units 3 and 4 Addendum No. 1 Appmved by:

C. R. Savage, Manager Core Design B Nuclear Manufacturing Divisions 1993 by Westinghouse Electric Corporation 9304i60075 9304i3 05000250 PDR. ADOCK P PDR

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nt oductio The purpose of this memo is to respond to the concerns voiced by Florida Power and Light (Reference 1) regarding the INCORE thimble deletion study. After reviewing the original INCORE instrumentation thimble deletion study memo (Reference 2) there were two issues for which FP&L requested more information. These issues are a) the impac" on deletion of thimbles due to failure of the rotary 10-path selector devices and b) the methodology used to calculate the peaking factor uncertainties when less than 75% of the thimbles are operable. This memorandum addresses these issues.

The original study (Reference 2) assumed that deletion of INCORE instrumentation thimbles was random in nature. The next section describes the deletion of thimbles via 10-path device failure. In addition, the original study did not provide the details of the methods used to calculate the peaking factor uncertainties for flux maps with thimbles less than the 75% 'required by the Standard Technical Specifications. The second and third sections describe this methodology in detail.

The 10-path rotary transfer device in the INCORE detector drive system is the final transfer point that determines which thimble a detector it will access. Qhen a 10-path device fails, precludes usage of the 10 thhables for which it controls access. The Turkey Point units have five drive systems that each'ave a 10-path rotary transfer device. Figure 3 shows the correspondence between 10-path selector positions for a given detector and the thimble IDs.

Since this study only considers removal of thimbles down to 50% of the total, up to 2 10-path devices can fail -- eliminating access to 20 of the thimbles. If three 10-path devices fail'hen 30 thimbles are deleted and less than 50% of the original 50 thimbles remain.

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In Reference 2 the core was divided into two sets of quadrants.

Thimbles were deleted at random and the minimum number of thimbles left in any one quadrant was determined. Quadrants are defined as they were in Reference 2 (see Figures 1 and 2). For this study, 10-path devices will eliminate the first portion of thimbles and thimbles will then be removed at random until 60% or 50% remain.

Therefore, four separate cases must be examined:

A) one 10-path failure with random deletion to 60% remaining B) one 10-path failure with random deletion to 50% remaining C) two 10-path failures (60% remaining)

D) two 10-path failures with random deletion to 50% remaining For the cases with two 10-path failures, all possible combinations of 10-path failures (A&B, A&C, A&D, A&E, B&C, etc) were examined to determine which combination left the fewest thimbles remaining in any one quadrant. The following table shows the results of removing the various combinations of 10-path devices.

With Failure of Drives A&B A&C A&D A&E B&C B&D B&E C&D C&E D&E M in Thimbles--- '0 per quad 5 6 7 5 5 6 6 7 5 6 Although several combinations left as few as 5 thimbles in any one quadrant, the B&C combination was used arbitrarily. That is, for cases with two 10-path failures, thimbles accessed by devices B & C were deleted. h similar methodology was used to determine the worst single detector drive to eliminate. Drive B was selected, leaving a miniaua of 8 thimbles in any one quadrant.

With Failure of Drive A B C D E Min Thimbles per quad 9 8 9 10 8 One thousand simulations were run for each deletion case (except case "C") using a simple computer simulation program. These simulations were run to determine the minimum number of thimbles that remain in

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any one quadrant after the specified number of thimbles are deleted.

The following table summarizes the results for the four cases described above.

From the above table it can be seen that the results are very similar to the random deletion examined in Reference 2. Here, with deletion to 60% of thimbles,

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or more thimbles remaining per quadrant. With deletion to

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50% of thimbles, there will be at least 3 +OLEIC or more thimbles remaining per quadrant.

The results from the random thimble deletion vere 60% of thimbles, greater than 98% of the time there vill be at least 4

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with deletion to 50% of +qg a+

J there vill be at least 3 thimbles or more thimbles remaining per 'quadrant.

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When deleting to 50% of the thimbles, the minimum remaining per quadrant is three.

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Com a o o eact ate ro s uke Po t t the e-Loo Co Data has been collected for a thimble deletion study of Westinghouse three-loop reactors. The conclusions of this study should be applicable to both the current cycles at Turkey Point and all future cycles if the Tech Spec changes are to be permanent ones. Flux maps were collected from three different three-loop reactors with different reload fuel management strategies. These other three-loop reactors all have INCORE thimble patterns identical to the Turkey Point units.

The three'reactors will be designated Plants "A", "B", and "C". The similarity of these plants to the Turkey Point units provides justification for comparison.

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Cycle 8 of plant "A" used an 18 month, low leakage loading pattern, with high discharge burnup, standard fuel, and WABAs. Cycle 4 of plant "B" was also an 18 month, low leakage design with standard fuel and part-length WABAs. Cycle 2 of plant "C" was a 12 month, low leakage design which fed OFA fuel following a first core with standard fuel. To further insure that the study was relevant to the Turkey Point units, several Turkey Point flux maps were chosen for comparison of reaction rate errors to the maps used in the study. The selection criteria for the Turkey Point flux maps are to select maps a) at various times in cycle life b) with at least 80% of thimbles used c) with 2D and 3D INCORE constants and d) from both units 3 & 4.

The following table describes the maps selected.

Case Thim Unit Cycle Hap Const Burnup Power No. Used No. No. No. Geom (MWD/t) (%HFP)

\ W 1 48 4 10 4 2D 1310 100 2 40 4 10 17 2D 11645 100 42 4 11 9 2D 4410 100 3

4 42 40 4

4 ll ll 9 17 3D 3D 4410 8906 100 100 5

6 44 3 10 19 2D 9275 100 Table 1 contains the reaction rate errors from selected flux maps from the Turkey Point Units. The mean, variance, and standard deviation of

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the reaction rate errors for each map are listed at the bottom of the table.

Table 2 contains the reaction rate errors from selected flux maps from the three-loop reload cores. The mean, variance, and standard deviation of the reaction rate errors for each map are listed at the bottom of the table. From this data it can be seen that the reaction rate errors for both the selected three-loop cores and the Turkey Point units are similar. The standard deviation for the Turkey Point units is for the other three-loop reload cores.

Therefore, the statistical analysis of peaking factor uncertainties from the three-loop study is applicable to the Turkey Point units.

Three maps were taken from plant "A" and two each from plants "B" and "C" for a total of 7 different reference flux maps. Five separate deletion maps were run for each of the reference flux maps for a total of 35 deletions. The method used to remove thimbles was random. This random deletion method was shown to be valid in section I. Traces were deleted from the reference map until 50% of the available thimbles remained. This is a more conservative approach than deletion to Just 50% of the total thimbles.

Data compiled from each flux map consists of a) the maximum measured F~ and F , b) the core average axial offset, c) the quadrant tilt (0) in the quadrant with the relative power furthest from 1.0, d) the minimua margin to F *K(z) limf.t (expressed in percent), and e) the F

xy at the point of minimum F *K(z) margin. Differences were calculated in terms of percentage changes in F , F~, and Fxy and relative difference in all other parameters using the following formulae:

4 ErrorTD (1 - FTD / FR f)

• 100 ErrorTD FR f- (2)

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where "FTD" is the parameter of interest from the deletion map, and "FR f" is the same parameter from the reference map with all available Ref thimbles. This data is compiled in Table 3.

The mean difference and standard deviation for the five deletion cases for each map were then calculated, as were the mean and standard deviation for all reload maps combined (35 cases).

After all of these data were obtained, a 95%-confidence /

95%-probability one-sided upper tolerance limit was constructed to quantify the thimble deletion uncertainty component using the following formula:

TDUC X comb

+ kS comb (3) where "TDUC" is the thimble deletion uncertainty component for the F , or F ),'omb"X b" is the mean Error>>

parameter of interest (F~, dH'y' for the parameter of interest for all 35 cases, "S comb ~" is the mean standard deviation for the parameter of'interest for all 35 cases, and "k" is the one-sided 95$ -confidence / 95%-probability tolerance limit factor for the specific sample size. For 34 degrees of freedom (35 data points less 1), the value of "k" is 2.176. This data is listed in Table 4.

Table 5 contains the calculations for the total peaking factor uncertainties associated with only 50% of the thimbles being operational. The negative biases present in all of the data (negative meaning the deletion maps gave more conservative measurements) were ignored for conservatism. For all of these calculations, the uncertainty for the parameter of interest (F~, F , and F ) was with the statistically independent measurement uncertainties hH'y'ombined already in the Tech Specs using the following formula:

2 2 UNC 1 + X + SQRT((TSUC - 1) + TDUC )) (4) combb where "X comb

" is the mean ErrorTD for the parameter of interest (as calculated by equation 2) for all 35 cases, "TSUC" is the standard

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Tech Spec uncertainty component (1.04 for F~ and 1.05 for F and xy F ), "TDUC" is calculated using Equation (3), and "SQRT" represents the square root function.

The resulting uncertainties for peaking factors with only 50% of thimbles operable are:

Peaking Factor Uncertainties for Deletion to 50% of Thimbles TSUC TDUC Combined Conservative F 1.04 + 1.05 +q,c 1.05 1.07 F"y 1.05 1.07 The TSUC and TDUC columns represent the Tech Spec and Thimble Deletion uncertainty components for the respective peaking factors. The "Combined" column is the statistically combined total uncertainty for the respective peaking factor (defined by equation 4). Two conservatisms were then added to the statistically combined uncertainties. The first conservatism rounds up the TDUC and the second doubles the rounded TDUC. The conservative value represents a conservative combination of the TSUC and TDUC. These conservatisms have no specific mathematical Justification; they are to'e used merely to allow for changing fuel management strategies and any extreme cases this study did not consider.

The variation in the measured axial offset and core quadrant tilts were calculated using the following formula:

Variation X +or- kS </SQRT(Populate.on) comb (5) comb mb These results are given in Table 6. As can be seen, deleting down to as few as 50% of the thimbles has little or no effect on the measured axial offset or core tilt when compared to the reference map. The w+

variation for the axial offset is J while the + g Ce variation for ths cora silt isi j 4 q, c.

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In the first section it was shown that the random INCORE instrumentation thimble deletion assumption was a valid one. Whether thimbles are deleted randomly or via 10-path device failure the results are the same. When deleting to 60% of the thimbles, the minimum number of thimbles that remain in any one quadrant is j +

When deleting to 50% of the thimbles, the minimum number of thimbles that remain in any one quadrant is at least 3.

Although the data compiled for determining peaking factor uncertainties was not taken from the Turkey Point units, the second section showed that the data is applicable. Determination of peaking factor uncertainties remains unchanged from the previous memo (Reference 2). With down to 75% of the thimbles available for use, the standard Tech Specs require a 4% and 5% uncertainty on F~ and F respectively. With only 50% of the thimbles available, an additional 1% and 2% are added making the uncertainties for peaking factors 5%

and 7% for F~ and F respectively. Within these uncertainties there are inherent conservatisms:

a) zeroing the negative values of Xcomb mb in TDUC and UNC b) rounding up F~ and F uncertainties c) doubling the TDUC components of total F~ and F uncertainties These peaking factor uncertainties are then applied to measurements using a ramp function as specified in the original thimble deletion study memo (Reference 2).

F measurement uncertainty 4% + (1.0)*(3 - T/12.5) hH F measurement uncertainty 5% + (2.0)*(3 - T/12.5)

Q where T is the number of operable thimbles remaining and must be between 25 and 37 inclusive. For cases with greater than 37 thimbles operable, the standard Tech Spec uncertainties apply.

rt The information supplied here is merely a supplement to the original memo (Reference 2). The full scope of the this study is contained in the original memo. Because different data vere used to analyze the peaking factor measurement uncertainties, all information in this memo supersedes that of the original memo ~ Attachment A includes the suggested Tech Spec changes that reflect the nev peaking factor measurement uncertainties.

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Core Quadrants Defined by the Horizontal and Vertical Axes

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Core Quadrants Oeflned by the Oiagonal Axes

Figuri 3 PATH SELECTOR POSITION VS CORE POSITION

Selected Turkey Point Units Flux liaps Reaction Rate Krrors

Tab I ~ 2 Selected Three-Loop Reload flux leaps ReactIon Rate Errors

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Table 1 Statlatloal Resulta for Al'I Deletion Napa

~ab e 5 Calculation of Uncertainties for 50% of Available Thimbles UNC(F ) 1 + X + SQRT((UNC* - 1) + TDUC ))

b ta UNC(F ) ~ 1 + X + SQRT((UNC* - 1) + TDUC ))

b UNC(F ) ~ 1 + X '~ + SQRT((UNC* - 1) + TDUC )) q,c.

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~Teb e 6 Calculation of Variability for 50% of Available Thimbles et:

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Variation Variation

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Attachment A Insert A: When the number of operable moveable detector thimbles (T) is less than 75% of the total, the 5% F measurement uncertainty shall be increased to [58 + (2.0)(3 - T/12.5)j where T (the number of operable t'mbles), must be greater than or equal to 50% of the total.

Insert B: When the number of operable moveable detector thimbles (T) is less than 75% of the total, the 4% F~ me'asurement uncertainty shallbe increased [4% + (1.0)(3 - T/12.5)) where T (the number of operable thimbles), must be greater than or equal to 508 of the total.

Insert C: A minimum of three (3) detector thimbles per core quadrant where two sets of quadrants are defined: 1) quadrants formed by the vertical and horizontal axes of the core and

2) quadrants formed by the two diagonals of the core. These quadrants are defined such that the instrumented locations along the axes dividing the quadrants are included in each of those 'ad]acent quadrants as whole thimbles.

Insert D: At least 90% of the detector thimbles must be operable at the beginning of cycle.

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Attachment A (continued)

Insert E: UBL is defined as the Base Load uncertainty factor that accounts for: manufacturing tolerance, measurement error, rod bow and any burnup and power dependent peaking factor increases. With at lease 75% of the detector thimbles operable, UBL is 9%. When the number of operable moveable detector thimbles (T) is less than 75% of the total, the UBL uncertainty factor shall be increased to:.

[9% + (2.0)(3 - T/12.5)]

where T (the number of operable thimbles), must be greater than or equal to 50% of the total.

Insert F: U~ is defined as the Radial Burndown uncertainty factor that accounts for: manufacturing tolerance, measurement error, rod bow and any burnup and power dependent peaking factor increases. With at. least 75% of the detector thimbles operable, U~ is 9%. When the number of operable moveable detector thimbles (T) i.s less than 75% of the total, the U~ uncertainty factor shall be increased to:

[9% + (2.0)(3 - T/12.5)j where T (the number of operable thimbles), must be greater than or equal to 50% of the total.

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POWER DISTRIBUTION L I HI TS 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR - F LINITING CONDjTION FOR OPERATION 3.2.2 iQ)Z) snal 1 be 1 imi ted by the fol l owing rel ationships:

L vq(Z) < [Fq] X [K(Z)] for P > 0.5 L

FQ(Z) < LFq] X [K(Z)] for P < 0.5 TJ v3 where: [FO) ~ 2.32 P ~ Thermal Power ated herma Power and K(Z) is the function obtained from Figure 3.2-2 for a given core height location.

APPLICABILITY: NSE 1 ACTION:

lith the measured value of F~(Z) exceeding its limit:

a. Reduce THERHAL POWER at least 1% for each It FO(Z) exceeds L

Fq(Z) within 15 minutes and similarly reduce the Po~er Range Neutron Flux - High Trip Setpoints within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; POWER OPERATION may proceed for up to a total of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; subsequent POWER OPERATION say proceed provided the Overpower Delta-T Trip Setpoints (value of

((a) have been reduced at least 1% for each 1% FO(Z) exceeds the liait; and A

b. Identify and correct the cause of the out-of-11m1t condit1on prior to increas1ng THERMAL POWER above the reduced power limit required by ACTION a. ~ above; THERHAL POWER say then be increased Provided FO(Z) is demonstrated through incore mapping to be within 1ts limit.

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POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREMENTS 4.2.2.1 If t:Fq) as predicted by approved physics calculations is greater than [Fq] and P is greater than PT as defined in 4.2.2.2, FO(Z) shall be evaluated by 4.2.2.2, 4.2.2.3 or 4.2.2.4 to determine if F<

is within its limit. If t.Fq3 , fs less than I:Fq3 or P is less than PT, Fq(Z) shall be evaluated to determine if Fq(Z) is within its limit as follows:

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

b. Increasing the measured F~(Z) component of the power dfstrfbutfon map by 3% to account for manufacturfng tolerances and further increasing the value by 5% to account for measurement uncertafntfes. Verifying that the requirements of Specification 3.2.2. are satisfied.

Swss1zm Co Fq(Z) < Fq(Z)

Where Fq(Z) fs the measured Fq(Z) increased by the allowances for manufacturing tolerances and measurement uncertainty and L

Fq(Z) fs the F~ limit defined fn 3.2.2.

3/4 2-5

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POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREHENTS Cont inued M

d. Measuring F~(Z) according to the following schedule:

1. Prior to exceeding 75% of RATED THERMAL POWER>>, after refueling,

2. At least once per 31 Effective Full Power Days.

e. With the relationship specified in Specification 4.2.2.l.c above not being satisfied:

1) Calculate the percent F~(Z) exceeds its limit by the following expression:

Maximlan F<(Z)

X 100 for P > 0.5 Over Z [F(P x K(Z)/P Maximum X100 forP (05 Over Z [Fg] X K(Z)/0.5 ur ng power escalation at the beginning of each cycle, power level may be increased until a power level for extended operation has been achieved and power distribution map obtained.

3/4 2-6

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LIMNI POMER DISTRIBUTION TS SURVEILLANCE RE UIREMENTS Continued

2) The following action shall be taken:

a) Comply with the requirements of Specfficatfon 3.2 .2 for Fq(Z) exceeding its limit by the percent calculated above.

4.2.2.2 Operation fs permitted at power above PT where PT equals the

. ratio of EFq] dfvfded by [Fq] ff the following Augmented Surveillance (Hovable Incore Detection System, NIDS) requf rements are satisfied:

a. The axial power distributfon shall be measured by MIDS when required such that the limit of gF~]"/P times Figure 3.2.2 is not exceeded. F~(Z) fs the normalfzed axial power dfstribution from thimble j at core elevation (Z).

I. If F~(Z) exceeds [F~(Z)]s as deffned in the bases by

< 4%, faeedfately reduce thermal power one percent for every percent by which [F~(Z)]s is exceeded.

2. If F~(Z) exceeds [F~(Z)]s by ) 4% fmaediately reduce

. thermal power below PT. Cor rectfve actfon to reduce F>(Z) be1ow the limit will permit return to thermal power not to exceed current PL as defined in the bases.

3/4 2-7

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POWER DISTR I BUT ION LIMITS SURVEILLANCE RE UIREMENTS Continued

b. F>(Z) shall be determined to be within limits by using MIDS to monitor the thimbles required per specification 4.2.2.2.c at the following frequencies.

l. At least once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and 2.

afterr.

Iaeediately following and as a minimum at 2, 4 and 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> following the events listed below and every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> there-

1) Raising the thermal power above PT, or

2) Movement of control-bank 0 more than an accumulated total of 15 steps in any one direction.

c. KIDS'shall be operable when the thermal power exceeds PT with:

l. At least two thimbles available for which N~ and@> as defined in the bases have been determined.

2. At least two movable detectors available for mapping F>(Z).

3. The continued accuracy and representativeness of the

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selected thimbles shall be verified by using the most recent flux map to update the lt for each selected thimble.

The flux sap must be updated at least once per 31 effective full power days.

3/4 2-8

POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREMEHTS Continued 4.2.2.3 Base Load operation is permitted at powers above PT if the following requirements are satisfied:

a. Either of the following preconditfons for Base Load operation must be satisfied.

I. For entering Base Load operation wfth power less than PT, a) Hafntafn THERMAL POWER between PT/1.05 and PT for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, b) Haintain the AFO (Delta-I) to within a + 2% or a 3$

target band for at least 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period.

c) After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> have elapsed, take a full core flux map to determine Fq(Z) unless a valid full core flux map was taken within the ifme period specfffed fn 4.2.2.1d.

d) Calculate PBL per 4.2.2.3b.

2. For entering Base Load operation with power greater than PT a) Nafntafn THERMAL POWER between PT and the power licit determined fn 4.2.2.2 for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and aafntafn Augmented Surveillance requirements of 4.2.2.2 during this period.

b) Nafntafn the AFD (Delta-I) to withfn a a 2% or a 3%

target band for at least 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, 3/4 2-9

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POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREMENTS Continued c) After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> have elapsed, take a full core flux map M

to determine F~(Z) unless a valid full core flux map was taken within the time period specified in 4.2.2,1d.

d) Calculate PBL per 4.2.2.3b.

b. Base Load operation is permitted provided:

1. THERMAL POWER is Iaintained between PT and PBL or between PT and 100% (whichever is most limiting).

2. AFD (Delta-I) is maintained within a i 2% or

• 3% target band.

3. Full core flux maps are taken at least once per 31 effective Full Power Days.

BL an T are defined as:

Nniasn [F<] V(Z)

~

X PBL Over Z <(Z) X W(Z) BL X L'6l

~ [Fq3"/[Fq3 where: F~(Z) is the measured F~(Z) with no allowance for manufacturing tolerances or measurement uncertainty. For the purpose of this Specification [Fq(Z)]~,p Meas. shall be obtained between elevations bounded by 10% and 90% of the active core height. [F~g" is the F~ limit. ll(Z) is given in Figure 3.2-2. X(Z)BL is the cycle dependent function that accounts for limited power distribution transients encountered during base load operation.

3/4 2-10

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POVER DISTR I BUT ION LIMNITS SURVEILLANCE RE L'IREHENTS Continued The function is given in the Peaking Factor Limit Report as per Specification 6.9.1.6.

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Ourfng Base Load operation, ff the THERNAL POWER is decreased below pT, then the condftfons of 4.2.2.3.a shall be satisfied before re-entering Base Load operation.

d. If any of the conditions of 4.2.2.3b are not maintained, reduce THERNAL POWER to less than or equal to PT, or, within 15 minutes initiate the Augmented Surveillance (MIDS) requirements of 4.2.2.2.

4.2.2.4 Operatfon fs permitted at powers above PT ff the following Radial Burndown conditions are satisfied:

Radial Burndown operation fs restricted to use at powers between PT and PRB or PT and 1.00 (whichever fs most, limiting).

The maxfmen relatfve power permftted under Radfal PRB, fs equal to the minimum value of the Burndown'peratfon, ratio of t:F<(Z)1/IF'(Z)]RB ~as

[Fq(Z)]RB Has ~ ~Fxy(Z)]gap Meas. x Fz(Z) x %ÃC and Uas t:Fq(Z)] fs equal to t,'Fq] x K(Z).

b. I full core flux map to determine [Fxy(Z)]~p Hcas. shall be taken wfthfn the time per fod specified fn Section 4.2.2.1d.2.

For the purpose of the speciffcatfon, fFxy(Z)]pap <eas. shall be obtained between the elevatfons bounded by 10% and 90$ of the active core height.

3/4 2-11

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POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREHENTS Continued

c. The function Fz(Z), provided fn the Peaking Factor Lfmit Report (6.9.1.6), fs determined analytically and accounts for the most perturbed axfal power shapes which can occur under axial power dfstrfbutfon control.

d. Radial Burndown operation may be utilfzed at powers between PT and PRB, or, PT and 1.00 (whichever fs most limiting) provided that the AFD (Delta-I) fs within a 5% of the target axial offset.

e. If the requirements of Section 4.2.2.4d are not maintained, then the power shall be reduced to less than or equal to PT, or within 15 minutes Augmented Surveillance of hot channel factors shall be fnftfated ff the power fs above PT.

4.2.2.5 @hen Fq(Z) fs measured for reasons other than meeting the requirements of specfffcatfon 4.2.2.1, 4.2.2.2, 4.2.2.3 or 4.2.2A an overall measured F~(Z) shall be obtained from a power dfstrfbutfon map and increased by 3% to account for manufacturing tolerances and further increased by 5% to account for measurement uncertafnty.

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POWER DISTRIBUTION LIMITS 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR LIMITING CONDITION FOR OPERATION N

3.2.3 FaH Shall be limited to the following:

N FaH < le62 [1.0 + 0.3(l-P)3. where P i THERMAL POWER D ERMAL P WR APPLICABILITY: MODE l.

AcTIon:

With N F<H exceeding its limit:

a. Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> reduce THERMAL POWER to less than 50% of RATED THERMAL POWER and reduce the Power Range Neutron Flux High Trip Setpoint to 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 />'.

Wfthfn 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of initially being outside the above limits, verify thnnugh tnonne fluX Ongoing that Fag SS nettnned tn utth$ n the above limit, 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-lfmft condition prior to fncreasfng THERMAL POWER above the reduced THERMAL POWER limit required by ACTION a. and/or b., above; subsequent POWER OPERATION iaay proceed provided N

that F<H fs demonstrated, through fncore flux sapping, to be ~ithin fts limft of acceptable operation prior to exceed1ng the following THERMAL POWER levels:

1. A nominal 95 of RATED THERMAL PNER,

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

3. Mfthfn 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 POWERS 3/4 2-14

4' l.6 S g' POWER DISTRIBUTION LIMITS SURVEILLANCE RE UIREMENTS 4.2.3.1 The provisions of Specification 4.0.4 are not applicable.

N 4 .2.3.2 F<H shall be determined to be within its limit through incore flux mapping:

a. Prior to operating above 75'f RATED THERMAL POWER after each fuel loading, and

b. At least once per 31 Effective Full power pays.

N 4.2.3.3 The measured F>H shall be increased by 4% to account for measurement error.

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3/4 2-15

II a INSTRUMENTATION MOVABLE INCORE DETECTORS LIMITING CONDITION FOR OPERATION 3.3.3.2 The movable Incore Detection System shall be OPERABLE with:

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i a. At least 7ji4 of the detector thimbles, a~~ C Q Sufficient movable detectors, drive, and readout equipment to map these thimbles.

t ~GTL,t D APPLICABILITY: When the Movable Incore Detection System is used for:

a. Recalibration of the Excore Neutron Flux Detection System, or

b. Monitoring the QUADRANT POWER TILT RATIO, or N

c. Measurement of F>H and Fq(Z)

ACTION:

With the Movable Incore Detection System inoperable, do not use the system for the above applicable aonftorfng or calibration functions. The provisions of Specifications 3.0.3 and 3.0.4 are not applicable.

SURVEILLANCE RE IREMENTS 4.3.3.2 The Movable Incore Detection System. shall be demonstrated OPERABLE at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by normalizing each detector output when required for:

I

a. Recalfbratfon of the Excore Neutron Flux Detection System, or

b. Monftorfng the QUADRANT POWER TILT RATIO, or

c. Measurewent of F>N and F~tZ) 3/4 3-36

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