ML19340A166

Unit 3,Cycle 2,Startup Testing Summary.

ML19340A166
Person / Time
Site:	Oconee
Issue date:	03/01/1977
From:	DUKE POWER CO.
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ML19340A163	List: ML19340A162 ML19340A166
References
NUDOCS 8001100637
Download: ML19340A166 (15)

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'i DUKE P0h'ER CCNPANY OCONEE NUCLEAR STATION .

UNIT 3, CYCLE 2 STARIUP TESTING Sul41ARY ,

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DUKE POKER CCNPAW OCONEE NUCLEAR STATION UNIT 3, CYCLE _2 STARIUP TESTING SLM1ARY INIRODUCTION The Cycle 2 Startup Test Program for Oconee Unit 3 consisted of pre-critical tests, zero power physics tests, and power escalation tests. This. report provides. a sumary of the zero power ~ and power escalation test results and includes, where appropriate, camparisons of measured and predicted values

- of important core parameters.

The zero power physics testing was initiated on October 29, 1976, and was completed on November 11, 1976. Testing was conducted with the reactor at Hot Zero Power conditions (532*F, 2155 psig, and 0% FP). The core para-meters measured included' all-rods-out critical boron concentration, iso-

thermal temperature and moderate coefficients of reactivity, individual control rod groups and total group reactivity worths, and differential boron worth measurements. The measurements and results are further described in Section I..

Following satisfactory completion of zero power physics testing, the power escalation testing began on November 11, 1976, and was completed on December 3, 1976. The power escalation tests included core power distri-bution measurenents at approximately 40% FP, 75% FP and 100% FP; power imbalance detector correlation tests; andmeasurements of reactivity co-efficients at power. All tests met their respective acceptance criteria.

Section-II describes the individual tests in more detail and summarizes the results of these tests.

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~I .- 2ERO PGiER PIWSICS TESTING A. Initial Criticality Cycle.2 initial criticality was achieved on Oconee 3 at 13:24

hours on November 7,1976 by first withdrawing control rods (Group 70 to 75% withdrawn and Group 8 to 15% withdrawn) and initiating a continuous but regulated feed and bleed deboration of the Reactor Coolant System. Inverse multiplication plots versus boron concentration and time ~were maintained, and the feed and bleed was teminated when these plots reached a value of approximately 0.15. Criticality was then achieved by withdrawing Control Rod-Group 7 from 75% to-81% withdrawn, with equilibrium conditions reached at 14

15 hours with Control Rod Group 7 at 84% withdrawn, and a Reactor Coolant Systen boron concentration of 1288 ppm.

This measured critical boron concentration of 1288 ppm met the

! acceptance criterion of 1200 ppm +100 ppm.

B. All Regulating Rods'Out Boron Concentration The.all rods'out configuration was achieved by boration of~ Control Rod Group 7 to approximately 95% withdrawn, and then achieving equilibrium boron conditions within the Reactor Coolant System.

The Reactor Coolant System boron concentration at these equilib-

l. rium conditions was sampled and measured to be 1313 ppm. Control

Rod Group 7 was.then withdrawn to its out limit, and the resulting-reactivity insertion corresponded to a-2 ppm increase in boron

. concentration. The measured All Rods Out Boron concentration with Control Rod Group 8 at 15% withdrawn was therefore 1315 ppm.

l This value of 1315 ppm met the acceptance criterion of 1253 ppm

< +100 ppn.

l l C. Temperature Coefficients of Reactivity With Control Rod Group 7 at 94% withdrawn and Control Rod Group 8 at 150 withdrawn, the Reactor Coolant System average temperature was varied from 532*F to 526*F, from 526*F to 536*F, and from 536*F to 532*F. 'A-temperature coefficient was then calculated for each temperature ramp by dividing the reactivity changes by their corresponding temperature changes.- The average value.was calculated to be -1.0 x 10 5(AK/K)/*F, which falls within the -

acceptance criterion limits of -1.05 x 10~5(AK/K)/*F +0.4 x 10 4

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(AK/K)/*F for that boron concentration.

By substracting the isothemal Doppler coefficient, the moderator coefficient of reactivity for each ramp was calculated and the average value was found to be +1.1 x 10 5(aK/K)/*F. This measured moderator coefficient value is less than 0.5 x 104(aK/K)/*F,and i therefore meets the acceptance criterion.

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D. Control Rod Worth Measurements Group integral and differential worths were obtained for Control Rod Groups 4 through 7 with Group 8 at 15% witndrawn by deboration from an all-rods-'out corfiguration. In addition, Safety Rod Groups 1 through 3 were measured by a control rod drop. The measured reactivity worths of Control Rod Groups 6 and 7 met the acceptance criterion of predicted value +20% of,the measured value; however, the measured value of Control Rod Group 5, based upon an initial analysis of the experimental data, did not meet the accept-ance criterion, and therefore the worth of Control Rod Group 4 was also measured.

A subsequent review of the experimental data indicated that there was a systematic error in the analysis of Control Rod Group 5, and upon correcting this error, the measured value of Control Rod Group 5 fell within the acceptance criteria. The measured value of Control Rod Group 4, however, did not meet the acceptance criterion, and its reactivity worth was again measured this time by boration, which yielded results consistent with the previous measurement.

The safety significance of the discrepancy between the measured l - and the predicted values of Control Rod Group 4 upon power operation of the unit was reviewed in detail, and it was con-cluded that since the measured values of each of the Control Rod Groups were less than the predicted values, the predicted values of the worst case stuck and ejected rods worths would be con-l servative. Since the total worth of the measured groups met the acceptance criterion, and since the calculated values of the beginning of cycle shutdown margin were much greater than the required margin, it was concluded that adequate shutdown margin l would exist for power operation.

As an additional precaution, however, a rod drop measurement of l safety rod groups 1 through 3 was performed. This reactivity, i who combined with the worth of the other control rod groups al-l ready measured, yielded a value of measured total control rod l worth wi+hin 4% of the predicted value, thus deaonstrating an

adequate shutdown margin.

! Revised control rod worths were then obtained from Babcock and Wilcox utilizing their RISIN-PDQ-07, 2D, discrete model, which was not used for the previously generated control rod worths. ,

Utilizing this revised predicted worth, the measured value of Control Rod Group 4 fell well within the acceptance criterion.

Table 1 illustrates the control rod worth measurement data as well as comparisons to pertinent predicted values.

E. Boron Worth Measurements Initially, the measured differential baron worth rhowed a small deviation from the~ predicted' value of 0.99%(AK/K)/100 ppm. A reanalysis of the boron samples indicated some inconsistencies in the initial sample measurements. Upon correcting the affected boron concentrations for this error, a differential boron worth of 1.038%AK/K/100 ppm was obtained, and met the acceptance criterion.

F. Ejected Rod Worth' Measurement in order _to measure the worst case ejected control rod worth, Rod 4 in Control Rod Group 6 (predicted to be the most reactive rod) was borated out of the core while Control Rod Group 5 was maintained at 0% withdrawn and Control Rod Group 8 at 15% with-drawn. The measured worst case ejected rod worth adjusted for all control rods inserted was 0.57%(AK/K). The error adjusted worst case ejected rod worth was calculated to be 0.60%(AK/K),

which meets the acceptance criterion requiring the error adjusted worth to be less than 1.0%(AK/h].

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9 II. -POWER ESCALATION SEQUENCE TESTING

A. ' Core Power Distribution'Results Core power distribution measurements were performed at 40% FP, 75% FP, and 100% FP in order to verify that the measured power distribution is consistent with the predicted distribution. Cor-rected instrument readings from the incore instrumentation were taken from the process computer while the plant was operating at these power plateaus and were then campared to calculated power distributions at comparable burn-up, rod pattern, boron concen-t tration, and power levels. The two power distributions were then compared, but no significant discrepancies were note:1.

The results of these comparisons are shown on the enclosed eighth core maps of radial and total peaking factors.

During the execution of the core power distribution test, the fol-

! lowing' parameters were checked:

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1. SPND background readings and background corrections

2. Reactor Power Imbalance Values l

3. Worst case extrapolated minimum INBR

4. Quadrant power tilt l

l 5. Extrapolated worst case maximum linear heat rate

6. Non-extrapolated worst case maximum linear heat rate

7. Tilt and imbalance values from back-up incore detectors.

l l All values checked were found to be reasonable and met the accept-

! ance criteria applied to them. Table 2 provides the results of the minimum DNBR and maximum linear heat rate measurements and

extrapolations and shows that all values, both extrapolated and measured, met the acceptance criteria.

B. Power Imbalance Detector Correlation Test Results The power imbalance detector correlation test was performed at the 75% full power plateau to verify that the out-of-core detectors l

measure core offset within the tolerances assumed in the Safety Analysis (i.e. , out-of-core offset = incore offset +3.5%) . The test verified that all four out-of-core detectors satisfy the desired offset correlation. A comparison of incore detector imbalance to back-up recorder imbalance showed that for all values of. imbalance measured, the maximum difference was 4.9% of im-balance, which is well within the +7.5% acceptance criteria.for incore to back-up incore calculated offset.

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C. ' Reactivity Coefficient at Power-4

- Both the temperature coefficient of reactivity and the power coefficient of reactivity were measured at the 100% full power plateau with no difficulties encountered. The temperature-

- coefficient was neasured to be -0.6816 x'10 4 (AK/K)/*F. This value

+ met the acceptance criterion requiring the moderator temperature coefficient,to be nonpositive. The measured power coefficient was

-0.719 x 10 4(AK/K)/% full power and met the acceptance. criterion that it be less than or equal to -0.55.x 10~4 (AK/K)/%FP.

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. TABLE 1 SGNARY OF CONTROL ROD WORE MEASUREMENTS

-ORIGINAL REVISED CONTROL R0D' BORON ~ PREDICTED PREDICFED MEASURED  % DEV1ATION GROUP ENDPOINT WORE WORE WORE FROM PREDICTED (ppmB) (%aK/K) .(%3K /K) (%3K /K)

ORIGINAL REVISED 1313(ARC)

,. Group 7 1200 0.85 0.78 0.762 -10.35 -2.3 Group 6 1113 1.15 1.16 1.043 -9.30 -10.08 Group 5 1056 0.76 0.77 0.6666 -12.37 -13.51 Group 4 987 1.01' O.84 0'.803 -20.50 -4.40 Grcup 1-3 N/A. 6. 01- . 5.61 6.10 +1.5 8.7 TUTAL 1-7 N/A 9.98 9.16 9.4 -3.9 +2.6 9

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9 MAXIbp1 WORST MAXIhul NORST ACCEPTABLE .

MINBpl CASE ACCEIrfABLE CASE- WORST WORST. ACCEI' FABLE-MAXIhD1 WORST ErfRA- CASE CASE. WORST -

LINFAR ' CASE  ?.'ORST EXTRA- P01ATED EXTRAP. EXTRA- CASE POWER llEAT MAXIbiiti CASE POLATION M\XBut MAXIhp1 POIATED EXINA LEVEL RATE UIR MINIhDI PONER U!R UIR MINihB1 MINIMUM'

%FP (KW/PT) .'(W/FT)- DNBR' LEVEL (IGV/FT) (KW/FT) DNBR DNBR 7 39.68 5.18 15.5 8.31 85.5 .11.00 -20.15- 2.38 1.30 74.48 9.17 15.5 4.20 105.5 12.48 20.15 2.31 1.30 99.07 13.645 15.5 '

2.97 105.5 13.98 20.15 2.25 1.30 h'

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40% FP RADIAL PEAKING FACTORS FIGURE 1 8 9 10 11 12 13 14 15 H 1.00 0.958 0.963 1.056 1.205 0.89 0.809 0.705 1.15 1.09 1.07 1.06 1.22 0.85 0.80 0.64 K 1.118 1.295 1.15 1.327 0.644 0.665 0.6277 1.23 1.21 1.15 1.35 0.62 0.71 0.59 L 1.020 1.057 1.267 0.9642 0.9301 0.5538 1.08 1.11 1.17 0.98 1.05 0.52 M 1.389 1.416 1.2486 0.966 1.41 1.34 1.27 0.99 N Largest Predicted Peak = 1.41 1.061 1.2154 10.6902 Largest Measured Peak = 1.416 1.09 1.10 0.70 Deviation = -0.4%

O bEASURED 0.7677 PREDICTED 0.?4 Core conditions for Predicted Core Conditions for Measured Peaking Factor Peaking Factors Group 6 = 90.3% wd Group 6 = 92.7% wd J

Group 7- = 12.9% wd Group 7 = 16.6% wd Group 8 .= 38.4% wd Group 8 = 37.6% wd Imbalance'= +0.25% FP Axial Imbalance = 1.43% FP Offset = +0.62% Max. Quadrant Tilt = 1.44% l l

Core Burn-up = 2.0 EFPD ' Core Burn-up = 2.0 EFPD l l

Core Power = 39.68%F~  !

40%.FP TOTAL PEAKING FACTORS FIGURE 2 8 9 10 11 12 13 14 15 H 1.384 1.34 1.37 1.27 1.56 .1.063 1.'005 0.822 1.48 1.41 1.35 1.32 1.50 1.01 0.93 0.74 K 1.635 1.848 1.572' 1.668 0.825 0.802 0.778 1.60 1.57 1.47 1.69 0.70 0.82 0.68 L 1.397 1.282 1.6325 1.215 1.115 0.6565 1.35 1.39 1.59 1.19 1.26 0.61 M 1.79 1.861 1.52 1.203 1.75 1.68 1.54 1.18 N. Largest Predicted Peak = 1.75 1.348 1.573 0.858 Largest Measured Peak = 1.861 1.37 1.33 0.84 Deviation = -6.3%

0 END 0.969 PREDICTED 0.90 Core Conditions for Predicted Core Conditions for Measured Peaking Factors: Peaking Factors:

-Group 6 = 90.3% wd Group 6 = 92.7% wd Group 7 = 12.9% wd. Group 7 = 16.6% wd

. Group 8 = 38.4% Group 8 = 37.6% wd Imbalance = +0.25% FP Axial Imbalance = 1.43% FP Offset

= O.62%' Max. Quadrant Tilt = 1.44%

Core Burn-up = 2.0 EFPD Core Burn-up = 2.0 EFPD Core Power = 39.68%.FP

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-75% FP RADIAL PEAKING FACIDRS FIGURE 3 11 12 13 14 15 8 9 10 H' O.987 0.938 0.928 1.055 1.184 0.896 0.818 0.723 1.13 1.08 1.03 1.05 1.21 0.86 0.82 0.67 K 1.099 1.268 1.129 1.333 0.642 0.681 0.652 1.21 1.19 1.14 1.34 0.63 0.73 0.'62 L 0.995 1.068 1.213 1.004' O.919 0.571 1.07 1.10 1.15 0.98 1.07 0.54 M 1.373 1.391 1.310 0.991 1.38 1.31 1.25 1.00 Largest Predicted Peaking N Factor = 1,38 1.042 1.207 0.706 Largest Measured Peaking Factor = 1.391 1.08 1.10 0.72 Deviation = -0.8%

0 MEASURED 0,784 PREDICTED 0.75 Core Conditions for Predicted Core Conditions for Measured Peaking Factors Peaking Factors Group 6 = 90.3% wd Group 6 = 92.7% wd Group 7 = 12.9% wd Group 7 = 16.6% wd Group 8 ~ = 32.3% wd Group 8 = 37.6% wd Imbalance = -0.28% FP Axial Imbalance = 1.43%FP Offset = -0.37% Max. Quadrant Tilt = 1.4%-

Core Burn-up = 4.0 EFPP Core Burn-up = 4.03 EFPD Core Power = 75% FP l 75% FP TUTAL PEAKING FACTORS FIGURE 4 11 12 13 14 15 8 9 10 H 1.227- 1.169 1.232 1.184 1.421 1.014 0.9726 0.82148 1.42 1.35 1.31 1.28 1.48 1.01 0.96 0.80 K 1.456 1.655 1.412 1.630 0.738 0.825 0.760 1.51 1.48 1.40 1.69 0.77 0.87 0.75 l

L 1.234 1.343 1.514 1.221 1.152 0.674 1.31 1.35 1.55 1.23 1.33 0.66 M 1.700 1.696 1.586 1.161 l 1.67 1.61 1.51 1.22 N Largest Predicted PF = 1.67 1.250 1.442 0.828 l Largest Measured PF = 1.70 1.32 1.31 0.85 Deviation = -1.8%

l 0 bEASURED 0.909 PREDICTED 0.89 l

Core Conditions for Predicted Core Conditions for Measured Peaking Factors Peaking Factors l -Group 6- = 90.3% wd Group 6 = 92.7% wd Group 7 = 12.9% wd Group 7 = 16.6% wd i

Group 8 = 32.3% wd Group 8 = 37.6% wd Imbalance = -0.28 FP Axial Imbalance = 1.43% FP Offset = -0.37% hkot. Quadrant Tilt = 1.4%

Core Burn-up = 4.0 EFPD Core Burn-up'= 4~.03 EFPD Core Power = 75% FP

100% FP RADIAL PEAKING FACIDRS FIGURE 5 8 9 10 11 72 13 14 15 H 0.986 0.933 0.923 1.053 1.163 0.916 0.816 0.744 1.13 1.08 1.03 1.05 1.20 0.86 0.83 0.68 K 1.092 1.258 1.121 1.328 0.653 0.702 0.67 1.20 1.19 1.13 1.33 ~0.64 0.74 0.63 L 0.984 1.052 1.18 1.01 0.93 0.58 1.07 1.10 1.15 0.98 1.08 0.56 M 1.359 1.37 1.32 0.997 1.36 1.30 1.25 1.01 Largest Predicted Peaking N Factor = 1.36 1.024 1.20 0.71 Largest Measured Peaking Factor = 1.37 1.08 1.10 0.72 Deviation = -0.7%

0 FEASURED 0.82 PREDI N 0.82 Core Conditions for Predicted Core Conditions for Measured Peaking Factors Peaking Factors Group = 90.3% wd Group 6 = 86.6% wd Group 7 = 12.9% Group 7 = 14% wd Group 8 = 32.3% wd Group 8 = 19.5% wd Imbalance = -4.37% wd Axial Imbalance = -2.74%FP Offset = -4.3% Maximum Quadrant Tilt = 1.25%

Core Burn-up = 4.0 EFPD Core Burn-up = 6.52 EFPD Core Power = 99.07% FP 100% FP TOTAL PEAKING FACIDRS FIGURE 6~

8 9 10 11 12 13 14 15 1.17 1.10 1.18 1.21 1.34 1.11 1.01 0.89 H 1.36 1.29 -1.25 1.29 1.54 .1.06 1.02 0.86 K 1.39 1.57 1.33 1.63 1.02 0.88 0.82 1.43 1.40 1.38' 1.76 0.82 0.92 0.80 L 1.16 1.28 1.47 1.23 1.20 0.72 1.30 1.40 1.61 -1.29 1.40 0.71 M Largest Predicted 1.53 '1.67 1.59 1.19 PF = 1.74 largest Mearsured 1.74 1.66 1.58 1.29 PF = 1.67 Deviation = 4.0%

N 1.26 1.42 0.86 1.37 1.37 0.91 l

0 MEASURED 0.93 PREDICTED 0.94 l-Core Conditions for Predicted Core Conditions for Measured Peaking Factors Peaking Factors Group 6 =-90.3% wd Group 6 = 86.6% wd -

Group 7 = 12.9% ud- Group 7 = 14% wd Group.8 =.32.3% wd Group 8 = 19.5% wd Imbalance = --4.37% FP Axial Imbalance = -2.74% FP.

Offset = -4.37% Maximu Quadrant Tilt = 1.25%

Core Burn-up: 4.0 EFPD . Core Burn-up = 6.52 EFPD Core Power = 99.07% FP

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