ML19322B667

Power Distribution Comparison Status Rept.

ML19322B667
Person / Time
Site:	Oconee
Issue date:	12/21/1973
From:	DUKE POWER CO.
To:
Shared Package
ML19322B664	List: ML19322B662 ML19322B667
References
NUDOCS 7912040687
Download: ML19322B667 (7)

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Reguistc.ri Cccet File

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l OCONEE NUCLEAR STATION l UNIT 1 Power Distribution Comparison I Status Report On November 20, 1973, Oconee Nuclear Station, Unit 1, was shut down with a core average burnup of 91.5 effective full power days (EFPD). During this shutdown, in accordance with design provisions, the control rod assemblies assigned to transient Control Rod Group 7 and safety Control Rod Group 4 were interchanged. Ilgures 1 and 2 present the control rod assembly group configurations f;r the intervals 0-to-91.5 EFPD and 91.5-to-191.5,+10 EFPD, _

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A comparison of measured and predicted radici power distributions, representative of the interval prior to the control rod group interchange, is given in Figure 3.

It can be seen that the measured and predicted peak radial power factors agree within 3.3 percent. Figure 4 presents a power distribution comparison for a core average burnup of 97.5 EFPD, i.e., af ter the control rod group inter-change at 91.5 EFFD. For this case the difference between the measured and predicted peak radial power factors is approximately 0.7 pcreent. The average absolute percent difference between the measured and predicted radial power factors, for assemblies having radial power factors within five percent of the measured peak radial power factor, is shown as a function of burnup in Figure 5.

The measured core power distributions were obtained using the fixed incore detectors. The location of these detectors is shown in Oconee FSAR Figure 7-18. The measured data were corrected, where possible, by replacing signals from inoperative detectors with values obtained by interpolation or extrapolation of signals from adjacent detectors. As indicated in Figures 3 and 4, however, one detector string was completely inoperative and no measured value is available.

Predicted power distributions were obtained from two-dimensional PDQ thermal-hydraulic feedback calculations, using a standard two zone representation for i

mach fuel assembly in one-quarter core geometry.

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,b can b2 seen in tha cttached figurso, the mea:ured and predictsd cora power distributions agree quite well. Particularly, it is apparent that the control rod group interchange at 91.5 EFPD did not adversely affect the validity of the PDQ predicted core power distributions.

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, CONTROL ROD GROLT LOCATION (0 to 91.5 EFPD)

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(2) (6) (2) ,

(5) (3) (3) (5)

(7) (8) (2) (8) (7)

(5) (4) (1) (1) (4) (5)

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(2) (8) (7) (3) (7) (8) (2)

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(3) (1) (6) (6) (1) (3)

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(6) (2) (3) (4) (3) (2) (6)

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(3) (1) (6) (6) (1) (3)

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(2) (8) (7) (3) (7) (8) (2)

M (5) (4) (1) (1) (4) (5)

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(5) (3) (3) (5)

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R l 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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(x)*-Control Rod Group Number

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Figure 1

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CONTROL ROD CROUP LOCATION

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(91.5 to 191.5 + 10 EFPD)

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(2) (6) (2) ,

c (5) (3) (3) (5)

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(4) (8) (2) (8) (4)

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(5) (7) (1) (1) (7) (5)

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(2) (8) (4) (3) (4) (8) (2) i c-(3) (1) (6) (6) (1) (3)

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(6) (2) (3) (7) (3) (2) (6) f (3) (1) (6) (6) (1) (3)

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(2) (8) (4) (3) (4) (8) (2)

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N (4) (8) (2) (8) (4) o (5) (3) (3) (5)

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(x) =-Control Rod Group Number i.

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1 Figure 2

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C(EPARISON OF MEASURED AND CALCULATED RADIAL CORE POWER DISTRIBUTIONS 1.46 1.42 1.38 1.52 1.52 1.40 1.13 0.66 1.42 1.41

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1.40 1.47 1.49 1.41 1.06 0.60 1.24 1.33 1.37 1.35 1.36 1.05 0.59 1.28 1.26 1.37 1,44 1.35 1.08 0.58

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0.79 1.20 1.18 1.18 0.89 0.43 0.77 1.20 1.19 1.17 0.91 0.42 1.14 1.07 0.94

• 1.15 1.03 0.93 0.62 0.56 0.66 0.36 0.54 0.61 0.35

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0.35 0.34

• Inoperative Detectot

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x.xx-- Measured y.yy--Calculated (PDQ)

CONDITIONS

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Measured Calculated Core Average Burnup (EFPD) 48.4 48.4 Power Level (%FP) 95 95 Soron Concentration (ppm) 925 925 Control Rod Group Position (%wd)

Group 1-5 100 100

Group 6 79 79 ,

Group 7 7 0 Group 8 17 37.5 i .

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COMPARISON OF MEASURED AND CALCULATED BADIAL CORE POWER DISTRIBUTIONS l0.61 1.03 1.24 1.42 1.42 1.25 0.92 0.59 0.62 1.03 1.30 1.43 1.41 1.27 0.84 0.52 0.98 1.31 1.35 1.33 1.18 0.95 0.55 1.03 1.31 1.39 1.38 ..' 26 0.97 0.52 1.35 1.21 1.19 1.20 0.89 0.40 1.34 1.23 1.16 1.16' O.89 0.41 0.71 1.16 1.07

• 0.73 1.08 1.06 0.68 1.20 0.95 0.48 1.09 0.87 0.43

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• Inoperative Detector 0.50 J

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x.xx-- Measured y.yy Calculated (PDQ)

C0hTITIONS

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Measured Calculated Core Average Burnup (EFPD) 97.5 97.5 Power Level (%FP) 75 75 Boron Concentration (ppm) 827 827 Control Rod Group Position (%wd)

Groups 1-5 100 .100 Group 6 51 51 Group 7 0 0 Group 8 7.6 37.5

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Figure 4

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COMPARISON OF MEASURED AND PREDICTED RADIAL POWER FACTORS

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• For Assemblies Having Radial

@ Power Factors Within Five

• Percent of the Measured Peak e

$ Radial Power Factor

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i i i i i i i i O 10 20 30 40 50 60 70 80 90 100 Core Average Burnup - EFPD