ML20092H474

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Cycle 4 Core Performance Rept
ML20092H474
Person / Time
Site: North Anna Dominion icon.png
Issue date: 05/31/1984
From: Ford C, Pierce N
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
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ML20092H449 List:
References
VEP-NOS-9, NUDOCS 8406260128
Download: ML20092H474 (50)
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Text

. _ - -

VEP-NOS-9 Vepco NORTH ANNA UNIT 1, CYCLE 4 CORE PERFORMANCE REPORT CO NUCLEAR OPERATIONS DEPARTMENT Virginia Electric and Power Company

i:. .

)

VEP-NOS-9 NORTH ANNA UNIT 1, CYCLE 4 CORE PERFORMANCE REPORT by C. Alan Ford and Nancy S. Pierce Reviewed: Approved:

C. d i C. T. Snow, Supervisor E [J.. Lozito Director Nuclear Fuel Operation N4 clear Fuel peration Nuclear Fuel Operation Subsection Nuclear Operations Department Virginia Electric & Power Company Richmond, Virginia May, 1984 i

i

CLASSIFICATION / DISCLAIMER The data, techniques, information, and conclusions in this report have been prepared solely for use by the Virginia Electric and Power Company (the Company), and they may not be appropriate for use in situations other than those for which they were specifically prepared. The Company therefore makes no claim or warranty whatsoever, express or implied,as to their accuracy, usefulness, or applicability. In particular, THE COMPAST MAKES NO WARRANTY OF MERCHANTABILITY OF FITNESS FOR A PARTICULAR PURPOSE, NOR SHALL AST WARRANTY BE DEEMED TO ARISE FROM COURSE OF DEALING OR USAGE OF TRADE, with respect to this report or any of the data, techniques, information, or co,nclusions in it. By making this report available, the Company does not authorize its use by others, and any such use is expressly forbidden except with the prior written approval of the Company.

Any such written approval shall itself be deemed to incorporate the disclaimers of liability and disclaime,rs of warranties provided herein.

In no event shall the Company be liable, under any legal theory whatsoever (whether contract, tort, warranty, or strict or absolute liability), for any property damage, mental or physical injury or death, loss of use of property, or other damage resulting from or arising out of the use, authorized or unauthorized, of this report or the data, techniques, information, or conclusions in it.

i

ACKNOWLEDGEMENTS The authors would like to acknowledge the cooperation of the North Anna Power Station personnel in supplying the basic data for this report.

Also, the authors would like to express their gratitude to Mr. C. T. Snow for his aid and guidance in preparing this report.

4 11

TABLE OF CONTENTS SECTION TITLE PAGE NO.

Classification / Disclaimer . . . . . . . . . . . .1 Acknowledgements . . .. . . . . . . . . . . . . 11 List of Tables . . . .. . . . . . . .. . . . . iv List <2f Figures . . . . . . .. . . . .. . . . .v 1 Introduction and Summary. . . . . . . . . . . . .1 2 Burnup ::'ollow . . . . . . . . . . . . . . . . . . 7 3 Reactivity Depletion Follow . . . . . . . .. . . 14 4 Power Distribution Follow . . . . . .. . .. . . 16 5 Primary Coolant Activity Follow . . ... . . . . 37

. 6 Conclusions . . . . . .. . . . . . . . . . . . 41 7

References. ..................42 111

LIST OF TABLES TABLE TITLE PAGE NO.

4.1 Summary of Incore Flux Maps for Routine Operation. .....20 6

I l

l i

l l

i l

iv

LIST OF FIGURES FIGURE TITLE PAGE NO.

1.1 Core Loading Map . . . . . .. .............. . .4 1.2 Movable Detector and Thermocouple Locations. .... . ... .5 1.3 Control Rod Locations. . .... .. . . ...... .. . . .6 2.1 Core Burnup History . . . . ............... . .9 2.2 Monthly Average Load Factor. ..... . . . .. .. .. . . . 10 2.3 Assemblywise Accumulated Burnup: Measured and Predicted . . . 11 2.4 Assemblywise Accumulated Burnup: Comparison of Measured and Predicted . . ... ... ..... . . . .. . . 12 2.5 Sub-Batch Burnup Sharing . .... . . . . . .. .. ..'. . . 13 3.1 Critical Boron Concentration versus Burnup - HFP-ARO . . . . . 15 4.1 Assemblywise Power Distribution - N1-4-07 . .. . . .. . . . 22 4.2 Assemblywise Power Distribution - N1-4-18 . .... ... . . 23 4.3 Assemblywise Power Distribution - N1-4-30 . .. .. .. . . . 24 4.4 Hot Channel Factor Normalized Operating Envelope . . ... . . 25 4.5 Heat Flux Hot Channel Factor, F (Z) - N1-4-07. . . . . . . . . 26 4.6 HeatFluxHotChannelFactor,Ff(Z)-N1-4-18.. ... . . . . 27 4.7 Heat Flux Hot Channel Factor, F (Z) - N1-4-30. . .. . . . . . 28 4.8 Maximum Heat Flux Hot Channel Factor, Fq *P, vs.

Axial Position . . . . . . . . . . . . . . . . . . . . . . . 29 4.9 Maximum Heat Flux Hot Channel Factor versus Burnup . . . . . . 30 4.10 Enthalpy Rise Hot Channel Factor versus Burnup . . . . . . . . 31 4.11 Target Delta Flux versus Burnup .. . . . . . . . . . . . . 32 v

a LIST OF FIGURES CONT *D FIGURE TITII PAGE NO.

4.12 Core Average Axial Power Distribution - N1-4-07 . . . . . . . 33 4.13 Core Average Axial Power Distribution - N1-4-18 . . . . . . . 34 4.14 Core Average Axial Power Distribution - N1-4-30 . . . . . . . 35 4.15 Core Average Axial Peaking Factor versus Burnup . . . . . . . 36 .

5.1 Dose Equivalent I-131 versus Time . . . . . . . . . . . . . . 39 5.2 I-131/I-133 Activity Ratio versus Time . . . . . . . . . . 40 vi .

Section 1 INTRODUCTION AND

SUMMARY

On May 12, 1984, North Anna Unit 1 completed Cycle 4. Since the initial criticality of Cycle 4 on November 18, 1982, the reactor core produced approximately 80 x 'O' MBTU (13,478 Megawatt days per metric ton of contained uranium) which has resulted in the generation of approximately 7.8 x 10' GTr gross (7.4 x 10' LHr net) of electrical energy. The purpose of this report is to present an analysis of the core performance for routine operation during Cycle 4. The physics tests that were performed during the startup of this cycle were covered in the North Anna Unit 1, Cycle 4 Startup Physics Test Report" and, therefore, will not be included here. ,

The second cycle core consisted of three batches of fuel: a twice burned sub-batch from cycles 2 and 3 (4A2), a once-burned batch from cycle 3 (Batch SA), and one fresh batch (Batch 6A). The North Anna 1. Cycle 4 core loading map specifying the fuel batch identification, fuel assembly locations, burnable poison locations and source assembly locations is shown in Figure 1.1. Movable detector locations and thermocouple locations are identified in Figure 1.2. Control rod locations are shown in Figure 1.3.

Routine core follow involves the analysis of four principal performance indicators. These are burnup distribution, reactivity depletion, power distribution, and primary coolant activity. The core burnup distribution is followed to verify both burnup symmetry and proper 1

batch burnup sharing, thereby ensuring that the fuel held over for the next cycle will be compatible with the new fuel that is inserted.

Reactivity depletion is monitored to ' detect the existence of any abnormal reactivity behavior, to determine if the core is depleting as designed, and to indicate at what burnup level refueling will be required. Core power distribution follow includes the monitoring of nuclear hot channel factors to verify that they are within the Technical Specifications

  • limits thereby ensuring that adequate margins to linear power density and critical heat flux thermal limits are maintained. Lastly, as part of normal core follow, the primary coolant activity is monitored to verify that the dose equivalent iodine-131 concentration is within the limits specified by the North Anna Unit 1 Technical Specifications, and to assess the integrity of the fuel.

Each of the four performance indicators is discussed in detail for the North Anna 1, Cycle 4 core in the body of this report. The results are summarized below:

1. Burnup Follow -

The burnup tilt (deviation from quadrant symmetry) on the core was no greater than i0.44* with the burnup accumulation in each batch deviating from design prediction by less than 0 . 5 *. .

2. Reactivity Depletion Follow -

The critical boron concentration, used to monitor reactivity depletion, was consistently within t0.40*.. AK/K of tha design prediction which is well within the 1*.

AK/K margin allowed by Section 4.1.1.1.2 of the Technical Specifications.

3. Power Distribution Follow - Incore flux maps taken each moath indicated that the assemblywise radial power distributions deviated from the design predictions by an average dif ference of less than 2*.. All hot channel factors met their respective Technical Specifications limits.

2

4. Primary Coolant Activity Follow -

The average dose equivalent iodine-131 activity level in the primary coolant during Cycle 4 was approximately 8.1 x 10 -2 C1/gm. This corresponds to 8% of the operating limit for the concentration of radiciodine in the primary coolant.

In addition, the effects of fuel densification were monitored throughout the cycle. No densification effects were observed.

3

Figure 1.1 NORTH ANNA UNIT 1 - CYCLE 4 CORE LOADING MAP R P 4 M L M J H 0 F C 0 C B A E02 F37 El3 1

024 F26 E53 8 F02 001  !

De r F12 74T L2n E06 E4l F67 rst ot7 12P 20P $$ 20P 12P 3 W W F36 20P E64 707 20P E61 F35 20 P W F47 20P E20 D43 4

046 Ft8 F0l E10 Flu T/E E18 022 F63 E15 FS7 F04 050 12P 20P 20P 20P 20P 12P S F26 - F38 20P E40 F45 20P W W20P ESO W 20P E47 F32 20P W F10 F43 20P 6 E55 FSO 12P E01 W 20P W Fts 20P E39 E56 8P E2S F24 20P W F46 E07 W W 20P 12P 1 F64 E09 W E54 E63 ' E30 E08 F40 20P E38 E22 E16 W E39 W W SP SP 55 8 LG4 F61 12P (44 F16 20P 045 F03 20P E29 W8P E17 F09 20P D14 W20P E27 W E14 12P 9 W F48 20P Y F59 20P E46 F49 20P E26 ' F29 20P E49 FS$ E36 F22 W 20P 20P 10 040 W 12P FS4 20P E3S FOS 20P 048 W 010 W E45 F48 W D39 20P 20P 12P 11 006 E33 F42 El2 ~ F66 E42 752 805 F65 E43 030

, 20P 20P 20P 20P 12 W F68 12P FOS 20P E62 E03 E28 F20 20P F27 12P W 13 006 W W12P E48 F69 12P F39 W 14

==> A$$EM8LY ID E56 W E23 1

15

==> ONE OF THE FOLLOWING A. SS = SEC040ARY SOURCE

8. MP = BURNA8LE PCISON A$$EMBLY (M NUM8ER OF R005)

FUEL ASSEMBLY DESIGN PARAMETERS SUB-BATCH 4A2 SA 6A Initial Enrichment (w/o U-235) 3.21 3.40 3.59 Assembly Type 17X17 17X17 17X17 Number of Assemblies 24 64 69 Fuel Rods per Assembly 264 264 264 Assembly Identification D01 D02 D06 E01-E64 F01-F69 D08 D10 D12 D13 D14 D17 D19 D20 D22 D24 D25 D26 D30 D32 D39 D40 D43 D45 D46 D48 D50 4

Figure 1.2 NORTH ANNA UNIT 1 - CYCL 5 4 MOVABLE DETECTOR AND THERMOCOUPLE LOCATIONS i

n P M M L m J M C F E O C S A MO . TC 1 TC TC MO 2 TC M0 TC 3 TC MO M0 No TC 4

> M0 Mo M0 MO TC MO TC TC MO TC TC 5 Mo TC TC MO TC MO 6 TC TC MO MG MO TC M0 M0 i Mo MD MO Mo TC TC TC TC TC TC M0 TC TC MO TC 4 MO TC Mo TC Mo TC MD 9 MO Mo M0 TC TC TC MO TC 10 MD Mo TC MO TC TC TC MO 11 Mo MD M0 TC TC TC MO TC 12 M0 M0 TC TC 13 T

TC Mo TC Ib MO - MoveOle Detector TC

  • Thereoccuple MO TC TC 15 5

Figure 1.3 NORTH ANNA UNIT 1 - CYCLE 4 CONTROL ROD LOCATIONS R P N M L K J H C F E D C B A 180 I .

Loop C l l Loop B 1 Outlet l Inlet N-41 N '^

1 SA lo l

H SA

^

l I SP l V 1 N-43 2

3 11 l l C lB 'l , B C l 4 1 \

SP l SB SP j SB 5 A B D l C D l B A 6 Loop C Loop B Into SA SB SB SP SA l Outlet 7 90*= D C lC D l - 270* 8 l I

, SA SP SB SB 11 1 SA l 9 1

'1 ,

1 l A B D C lD B A 10 SB 1 SP SB SP 11 l

C B B 'C 12 1

SP SA l SA 13 N-44 l\ l _ 11 N=42 l A- 0 A 14 l 11 Loop A l oop A Abso rbe r Outlet inlet Ma te ri a l l Ag-in-Cd O' Function Number of Clusters Control Bank D 8 Control Bank C 8 Control Bank B 8 Control Bank A 8 Shutdown Bank SB 8 Shutdown Bank SA 8 SP (Spare Rod Locations) 8 6 -

/

.  ?,

(

/

\

Section 2 BURNUP FOLLOW t The burnup history for the North Anna Unit 1, Cycle 4 core is .

graphically depicted in Figure 2.1. The unit remained shutdown from November 20, 1982, until December 4, 1982, for the replacement of a main station transformer. The unit remained shutdown from December 5,1982, until March 8, 1983, for the replacement of three main station

  • transformers and the main electrical generator. The North Anna 1, Cycle 4 core achieved a burnup of 13,478 Md/MTU. As shown in Figure 2.2, the average load factor fpr Cycle 4 was 65*. when referenced to rated thermal power (2775 MW(t)). ,

) \

Radial (X-Y) burr.up distribution maps show how the core burnup is ; ,

shared among uhe various fuel assemblics, and thereby allow a detailed burnup distribu' tion analysis. The NE'. TOTE computer code is used to 8

calculate these assemblywise burnups. Figure 2.3 is a radial burnup '

I distributi6n map in which the assemblywise burnup accumulation of the core

\ t at the end of Cycle 4 operation is given For comparison purposes, the design values are also given. Figure 2.4 is a radial burnup distribution

)

map in which the percentage difference comparison of measured and predicted assemblywise burnup accumulation at the end of Cycle 4 operation . ,

\ .

t <

is also given. As c,an be seen from this figure, the accumulated assembly

, t \

burnups were generally within t3*. of the predicted values. In addition, i

deviation from quadrant symmetry in the core, as indicated by the burnup tilt factors, was no greater than 10.44L The burnup sharing on a batch basis is monitored to verify that the core is operating as designed and to enable accurate end-of-cycle batch

'N t, 7

',-(-

c . . _ - .. -.-. _ . _ - . _ . __ _ __ - -

'e , .

. .}y> '

i/ ) ,- >

E, ,b t} , ,.

~* t

}

,o l n

4' ,h jf. burnup predictions' to be made for use in reload fuel design studies.

3 Batch definitions ars given in Figure 1.1. As seen in Figure 2.5, the batch burnup sharing for North Anna Unit 1, Cycle 4 followed design predictions closely with each batch deviating less than 0.5*. from design.

4 Symmetric burnup in -conjunction with agreement between actual and predicted a'ssemblywit.e burnups and batch burnup sharing indicate that the I p- ,

'; t .,' r Cycle 4 core did, deplete as designed.

t b

n y

v . ,

h g l 3

s

  • *j i ? i 4

^

.<, l ~ '_

s j, .h s- .

y

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+ ,

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t I J

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4 i 8

Figure 2.1 NORTH ANNA UNIT 1 - CYCLE 4 CORE BURNUP HISTORY 18000 17000, 16000 15000 14000 ~

C Y 13000' '

y-C L 12000' E  :

l B

11000'

/

U 10000 ,

/

R N '9000 j V /

.P 8000 I

/

M 7000 #

H 0 6000 f

/

M T

5000 '

l U. 4000 /.

~

3000' ,/

2000;' ,

1000' g

/

0- )

b0 bb0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 N O J F M R M J J R S 0 N O J F M R M J l 0 E A E R P R U U U E C 0 E A E R P R U V C N B R R Y N L G P T V C N B R R Y N 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 2 2 3 3 3 3 3 3 3 3 3 3 3 3 4 .4 4 4 4 4 TIME (MONTHS 1 l

CYCLE 4 MAXIMUM DESIGN BURNUP -

16500 MWO/MTU l ---- BURNUP WINDOW FOR CYCLE E DESIGN - 13500 TO 16500 MN0/MTU u

Figure 2.2 NORTH ANNA UNIT 1 - CYCLE 4 MONTHLY AVERAGE LOAD FACTOR 100 -

90 -

80 -

70 -

60 -

50 -

40 -

30 -

20 -

10 -

i L P N R .

: : : : : : : : : : : : : : : : : : e MONTH Auf RZ R LE bR NbNhH (EXCLUDES REFUELING OUTRGES) 10

4 e

Figure 2.3 I

i 1

l NORTH ANNA UNIT 1 - CYCLE 4 ASSEMBLYWISE ACCUMULATED BURNUP MEASURED AND PREDICTED (1000 MWD /MTU)

R P N M L K J M G F E D C 8 A 1 1 22.521 9.834 22.241 1 MCA$URED 1 1

..............1 22.421. 9. 6.S.8

...... 22.421..............

. ...... 1..PRED.IC.1E.D

... . .. l 2 1 32.598 11.911 14.1SI 25.23l 14.138 12.011 32.591 2 1 32.291 11.971 14.098 25.351 14.091 11.978 32.291 3 1 33.44l 13.011 15.621 28.818 30.541 28.971 15.758 12.991 33.721 3

.......8.33 471.12

.. . ... .721.15

... . .. 711

.. 29 261.30.9.81 29.261.15

...... . ... 716.12

. ... 721.33 ... 471.......

4 1 33.911 20.768 15.891 30.121 17.028 31.681 16.871 30.161 15.898 21.091 33.851 4

.......1.33 .56..l.20.738.13.

.... .. 731.30.321.17.051.31.821.17.051.30.

..... .... .... .. . ... 321.15. 731 20.731.33

.. ...... 56.1.......

S 1 32. 341 12.641 15.611 32.231 17.491 36.671 30.771 36.451 17. 381 32.2$ 1 15. 731 13. 381 32.8 71 S 1.32.331.12

.... . .. . 721.15

. 731.32. ..351.17

. .. . 4 ...

71.36 ...79. 8.31.081.36

.. ..... . ..791.17.471.32

. .. . ... ...351.15 731.12 7el.32.35.l 6 1 11.791 15.578 29.591 17.321 32.698 17.191 32.548 17.191 32.821 17.211 30.218 16.058 12.621 6

.......1.11.971.15 711.30.181.17.478.32

... . . ... .... ..... 981.17.421.32.541.17.428.32.981.17.478.30.181.15

.. ..... ..... ..... .. .. ..... .... . ... ... . 711.11.971.......

7 1 22.268 13.891 29.021 16.771 36.521 17.011 32.118 27.591 32.201 17.181 36.291 16.711 28.741 13.931 22.301 7 1 ..

22 411 _... 14.09.1 29. 2.11.17

. .. 0$.1.36

. ... .....821.17.421.32.41l.28.12

..... . .... . ... .8.32 .. .411.17

... . 421.36

. . .. ... 821.17

.. .05.l.29

......211.14.09 6 22.411 8 I 9.511 25.141 30.478 31.551 30.94l 32.128 27.401 17.111 28.001 32.151 30.911 31.591 30.481 25.721 9.851 8

1. 9..651 2.5 .. 618.30 761.31.861.31.221.32.368

. .. ..... .... ..... .... ... 2.7.881.17.20.1 2.7.881 ..... . 32. 36.1.31.228.31.861.30.761

.... ..... ..... .. . . 25 611. 9. 651 9 l 22.451 13.941 29.011 16.921 36.821 17.251 32.011 28.311 32.16l 17.191 36.771 16.781 29.311 14.178 22.778... 9 1 22. ... 411.14.091... . . . .29 2.11.17

. ... 051 36.821.17.428.32....411 28.

.. ..... 12.1

. .. ... 32 411.17

. ... ... .. 42!.36.821.17

. . .. . .. 051 29 2.11.14.09.1 ... 22. 411 10 1 11.901 15.768 30.34l 17.668 32.931 17.051 32.081 17.128 32.671 17.261 30.131 15.801 12.231 10 l 11

.... 9 71.15

.. . ..718.30.181.17.4

..... ..... .. . . ...71.32.98 4.17 421.32. ... >4 .8.17 421.32.981.17.47

... .... ..... . .. __ ___!.30 181 15. 711 11.9.71 . .

11 1 32.621 13.301 16.128 32.411 17.SSI 36.698 30.831 36.421 17.201 32.121 15.708 12.871 32.281 11 d

1.32 . .351.12

. . ...721.15

. .. ...738.32.351.17.471.36

. ..... . .. 791.31.081

.... _ 36.791.17.471.32.351.15

- .... .... . .. ... 731.12.72.1.32.. 351 12 1 33.611 21.001 15.901 30.731 16.811 31.494 16.761 29.891 15.731 20.998 33.768 12 4.33 S6 .. 8 20. .. 731.15

.. 731.30 321.17.051.31.821.17.nS.t.30.

. .. .... ... .... .. .321.15

.. .....73 . .8 20. 73 8 33 56.8 13 4 33.971 13.214 15.941 29.4?l 30.858 29.038 15.93! 12.811 33.571 13 1.33 478.12.721.15

... ... . . . . ..... 711 ...

29.261.30.981

.. .. . ... .... 29 261.15 718.12.728.33 471 ...

14 1 32.601 12.541 14.3St 25.521 14.091 12.021 32.121 14 1.32

. .291.11.971.14.09.4

. ... . ... 25..35.1.14.091.11.971.32.

.... ... . 291 15 l 22.971 10.011 22.771 15 1 22.428.

...... .... 9.651

.. ... 22 421 R P N M L R J H G F E D C 8 A 11

Figure 2.4 NORTH ANNA UNIT 1 - CYCLE 4 ASSEMBLYWISE ACCUMULATED BURNUP COMPARISON OF MEASURED AND PREDICTED (1000 MWD /MTU)

R P N M L K J H G. F E D C 8 A ,

1 I 22.521 9.838 22.241 1 MEAsunto i 1 lM

. . .. .. .... . ...1. 0. ...

4 71..1.

. 8. 8 1...+...0 81 1. .... . .. . . . . . . ..../.P . %..D

......I F F l 2 8 32.591 11.918 14.15l 2S.231 14.131 12.011 32.591 2

.......1. 0 941. 0. 56.1. 0.401. 0.494. 0.301. 0.291. 0.931.......

3 1 33.441 13.011 15.621 28.811 30.541 28.978 15.751 12.991 33.721 3

.......1. 0. 081. 2. 2.31.-0. 561. .l.561. l.411. 1.011. 0.=.258 2.141. 0. 748.......

.. . . . ... ..... .... . __ =. ...

4 1 33.911 20.761 15.891 30.121 17.021 31.684 16.871 30.161 15.891 21.051 33.851 4 l 1

........... 0. 31. 0 161..1. . ... .. 061..-0. 641. 0.131.

... ..... . . 0. 46.1. l . ... 011.. . ..0. 501..1. ... 0 31..1.....521. 0. ..8 7 8.......

$ 1 32.341 12.641 15.611 32.231 17.491 36.671 30.771 36.451 17.381 32.251 15.731 13.381 32.871 5

..l 0.041. ... ...0.6.11..-0.

. 711.-0.

. . . .. .. 368.

...... 0 10.1. 0,341. t.071. w.... 0.941.-0.

... .. . 5.21...0 .311. 0.048.

. ..... . ... .5 191..1.60.8 6 l 11.79f 15.578 29.591 17.321 32.691 17.191 32.541 17.191 32.821 17.218 30.211 16.051 12.621 6

........I. ..... 1.S$.1.-0.

. .. .. . .. 848. 1.951.

.. ... . 0 891.-0.891...1.311. .. . . ... 0 ...011. ...= 0. 501. 1.521 0.101 2.171=== 5 411.......

1.361.

7 1 22.261 13.891 29.021 16.778 7 2.36

..l.0.6.71. .1.441..-0.671.*.1.611.36.521

.. . . .... ... . .... 0.=.838==______.1=___0.921 __ 17.011 1.901..'O.

... 32.118 27.591 641...l.381..1.451. .1.981.

... .... ... . . . ... .. .... ...... 32.201 1.601..1.121. 17.181 0.52836.291 16.718 8 I 9.511 25.141 30.474 31.551 30.941 32.121 27.401 17.111 28.001 32.151 30.911 31.591 30.48l 25.721 9.851 8 l 1

.... 42.1. 1.821. 0. 9.36 ..... 0.4Si 031

. ...... . 0.978. 0.901.

. ...... .... . 0.730.

... ... . .1.721. 0.551. 0. 431. .. ... 0.631. 1. 0.18. . . . . 0 851. 0.901________=.2. ..

9 8 22.451 13.941 29.011 16.921 36.821 17.256 32.011 28.311 32.161 17.191 36.771 16.781 29.311 14.171 22.771 9 1

1. 0. 17)...... 0.31..-0.711. ... . 0...731.*.0. 0.16...l.006..1.211.

. ... .. . 0... 671. 0...771..1.331.-0.151...l.5.38.

.. ..... . 0.311.

... . . .. 0 591..1.591 ...

10 8 11.90f IS.768 30.341 17.661 32.931 17.051 15.801 12.231 10

.I... 0. 584. ... 0

....314. 0.531..1.054..-0.

.. ... .. ... .. 428. 161.

1 2 ..188.32.081

.1.721.-0

... . ... . 961...1.19.1..-0 .. 17.121 .181 32.678 0.621 2168

==______._--- ..17.261 30.131 11 l 32.621 13.301 16.121 32.481 17.558 36.691 30.831 36.421 17.201 32.121 15.701 12.871 32.231 11 0.178 0.421 -

1. 0. .. ... ...

821. =____

4 571. 2.531_____====. 0. 281. ... 0 821.. ... . .1.021.

... . .. .1.58.4..-0 ... 711. .... 0.151..1.161..O ... . ... 241 12 1 33.61) 21.001 15.901 30.734 1 15.731 20.991 33.76i 12

1. 0 151..1.301..1.101..1.378. 6.811 31.491 16.761 29.8Si.. . .. 381. 1.0.31...1.664..

1 13 i 33.971 13.211 15.94! 29.421 30.851 29.031 15.931 12.811 33.571 --................ 13 l ARITHMCTIC AVC l 1..1.491..3.814.

.... ______1.461..... 0.521.-0.411..-0.

...... 811..1.391.

.. ... . .. .... 0 724. 0.291 14 1 32.601 12.541 14.35l 25.521 14.091 12.021 32.121 .I.PC..T OlFF.. = 0. 01)

......... 14

................ 1. 0. 971.

.. ....4.761..1.831=____ 0.671. 0.041. 0. 401..-0.

=. ..... .. 531 15 1 STANDARD DEV l l 22.971 10.011 22.771 i AVO ABS PCT 1 15 1....=.0 92.......1. 1. 2. ..461..3 761..1.581... ... .l.DIFF = 1.07 1 It P N M L M J H C F E D C 8 A BURNUP SHARING BURNUP TILT (MWD /MTU)

Batch Cycle 2 Cycle 3 Cycle 4 Total NW~= -0.40 4A2 10951 15260 8057 34268 NE = +0.03 SA --

14868 13882 28750 6A -- --

14987 14987 SW = +0.44 Core Average 13478 SE = -0.06 l 12 l

i

Figuro 2.5 NORTH ANNA UNIT 1 - CYCLE 4 SUB-BRTCH BURNUP SHARING SUB-BRTCH : 4A2 SR 6R SYMBOL . DIRMONO SOUARE TRIANGLE 40000 36000~

~

.v 1/

32000 .

p v '

~

s M

- /

S 26000 ^ "'

, l A

-/"

T 24000 f C y H g B

/

U 20000 - f R _ f N /

N /

16000 -

7 H  :

n O

f

/ s /

M 12000 f f

b /

/

8000 ./

/

/

y r 4000 /

./

2

/

0-/ - , ,.

2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP MHD/MTU 13

.-v . .

Section 3 REACTIVITY DEPLETION FOLLOW The primary coolant critical boron concentration is monitored for the purposes of following core reactivity and to identify any anomalous reactivity behavior. The FOLLOW' computer code was used to normalize

" actual" critical boron concentration measurements to design conditions taking into consideration control rod position, xenon and samarium concentrations, moderator temperature, and power level. The normalized critical boron concentration versus burnup curve for the North Anna 1, Cycle 4 core is shown in Figure 3.1. It' can be seen that the measured data typically compare to within 51 ppm of the design prediction. This corresponds to less than 0.40*. AK/K which is well within the 1*. AK/K criterion for reactivity anomalies set forth in Section 4.1.1.1.2 of the Technical Specifications. In conclusion, the trend indicated by the critical boron concentration verifies that the Cycle 4 core depleted as expected without any reactivity anomalies.

i.

I l

l l

14

Figuro 3.1 NORTH ANNR UNIT 1 - CYCLE 4 CRITICAL BORON CONCENTRATION VS. BURNUP HFP-ARO X MERSURED -

PREDICTED 1600 1

1400

~

C R

I T 1200 ~

1 C

I R

L \

B 1000

  • 0 *R ,

O \ --

N  : '$

C 800 N-0  %

N .

E  %

600 R ,

?

1  %

4 400.

Ss i

M 200-- k h t m

0-i .- , , .,

0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MWD /MTU) 15

Section 4 POWER DISTRIBUTION FOLLOW Analysis of core power distribution data on a routine basis is necessary to verify that the hot channel factors are within the Technical Specifications limits and to ensure that the reactor is operating without any abnormal conditions which could cause an " uneven" burnup distribution. Three-dimensional core power distributions are determined from movable detector flux map measurements using the INCORE' computer program. A summary of all full core flux maps taken since the completion of startup physics testing for North Anna 1, Cycle 4 is given in Table 4.1. Power distribution maps were generally taken at monthly 1-cervals with additional maps taken as needed.

Radial (X-Y) core power distributions for a representative series of incore flux maps are given in Figures 4.1 through 4.3. Figure 4.1 shows a power distribution map that was taken early in cycle life. Figure 4.2 shows a power distribution map that was taken near mid-cycle burnup.

Figure 4.3 shows a map that was taken at the end of Cycle 4 life. The radial power distributions were taken under equilibrium operating conditions with the unit at approximately full power. In each case, the measured relative assembly powers were generally within 5.1% of the predicted values with an average percent difference of approximately 1.7%

which is considered good agreement. In addition, as indicated by the INCORE tilt factors, the power distributions were essentially symmetric for all cases.

l4 important aspect of core power distribution follow is the monitoring 16

of nuclear hot channel factors. Verification that these factors are within Technical Specifications limits ensures that linear power density and critical heat flux limits will not be violated, thereby providing adequate thermal margins and maintaining fuel cladding integrity. The Technical Specifications limit on the axially dependent heat flux hot channel factor Fq (Z) was 2.20 x K(Z), where K(Z) is the hot channel factor normalized operating envelope. Figure 4.4 is a plot of the K(Z) curve associated with the 2.20 F q(Z) limit. The axially dependent heat flux hot channel factors, F q(Z), for a representative set of flux maps are given in Figures 4.5 through 4.7. Throughout Cycle 4, the measured values of Fq(Z) were within the Technical Specifications limit. A summary of the maximum values of axially-dependent heat flux hot channel factors measured during Cycle 4 is given in Figure 4.8. Figure 4.9 shows the maximum values for the Heat Flux Hot Channel Factor mes'.sured during Cycle 4. As can be seen from the figure, there was a 19*. margin to the limit at the beginning of the cycle, with the margin remaining relatively constant throughout cycle operat; ion.

The value of the enthalpy rise hot channel factor, F-delta H, which is the ratio of the integral of the power along the rod with the highest integrated power to that of the average rod, is routinely followed. The Technical Specifications limit for this parameter is set such that the critical heat flux (DNB) limit will not be violated. Additionally, the F-delta H limit ensures that the value of this parameter used in the LOCA-ECCS analysis is not exceeded during normal operation. The Cycle 4 limit on the enthalpy rise hot channel factor was set at 1.55 x (1+0.3(1-P)) x (1-RBP(BU)), where P is the fractional power level, and RBP(BU) is the rod bow penalty. A summary of the maximum values for the Enthalpy Rise Hot Channel Factor measured during Cycle 4 is given in Figure 4.10.

17 l

1 l

The Technical Specifications require that target delta flux

  • values be determined periodically. The target delta flux is the delta flux which would occur at conditions of full power, all rods out, and equil'ibrium xenon. Therefore, the delta flux is measured with the core at or near these conditions and the target delta flux is established at this measured point. Since the target delta flux varies as a function of burnup, the target value is updated monthly. Operational delta flux limits are then established about this target value. By maintaining the value of delta flux relatively constant, adverse axial power shapes due to xenon redistribution are avoided. The plot of the target delta flux versus burnup, given in Figure 4.11, shows the value of this parameter to have been approximately -1% at the beginning of Cycle 4. After approximately

( one-half of the cycle, delta flux values had. shifted to -6.5'.' and then moved to -5% by the end of Cycle 4.

The power shift indicated by the delta flux values can also be observed in the corresponding core average axir.1 power distribution for a representative series of maps given in Figures 4.12 through 4.14. In Map N1-4-07 (Figure 4.12), taken at approximately 300 WD/MTU, the axial power distribution had a slightly flattened cosine shape with a peaking factor of 1.18. In Map N1-4-18 (Figure 4'.13 ) , taken at approximately 7,000 WD/MTU, the axial power distribution had shifted toward the bottom of the core with an axial peaking factor of 1.17. Finally, in Map N1-4-30 (Figure 4.14), taken at approximately 12,500 WD/MTU, the axial peaking factor was 1.18. The history of F-Z during the cycle can be seen more clearly in a plot of F-Z versus burnup given in Figure 4.15.

Pt-Pb

  • Delta Flux = X 100 where Pt = power in top of core (W(t))

2775 Pb = power in bottom of core (W(t))

18

_ _ , _ _ _ _ _ _ _ _ _ _ _ , _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ^ - - - - ' - "

In conclusion, the North Anna 1, Cycle 4 core performed satisfactorily with power distribution analyses verifying that design predictions were accurate and that the values of the F (Z) q and F-delta H hot channel factors were within the limits of the Technical Specifications.

O e

19

i

! TABLE 4.1 NORTH ANNA UNIT 1 - CYCLE 4

SUMMARY

OF INCORE FLUX MAPS FOR ROUTINE OPERATION 1 1 1 I 1 2 i F-Q (T) lloi BURN l F-DH(N) 190T ' CORE F(Z) 4 UP '

BANK l CHANNEL FACTOR CHNL. FACTOR MAX 3 QPTR AXIAL NO.

MAP DATE MWD / PWR D _ F(XY) 0FF OF NO. MTU (%) STEPS , AX1AL AX1AL MAX l THIM ASSY PIN POINT F-Q(T).

ASSY PIN F-DH(N) PolNT F(Z) l MAX LOC SET

(%) BLES 4

_ l _

I 305 100 221 006 I DE 7 3-24-83 29 1.765 K09 Ji 1.393 29 1.176 1.513 1.009 NE -1.16 45 10( 5) 4-14-83 1112 100 222 K09 Ji 30 1.700 K09 .J1 1,198 29 1.177 1.502 1.007 SW -0.89 47

' 5-16-83 ; 2232 '100 22T i 11 006 DE 29 1.722 J06 IH ' 1.404 29 1.170 1.472 1.007 SW -0.64 39 l 12 5-20-83 2382 '100 228 LIO lil 39 1.710 J06 IH 1.401- 38 1.175 1.465 1.006 SW -3.01 40

13 6-20-83 3394 100 224 LIO lH. 38 '

1.714 L10 IH 1.414 38 1.159 1.483 1.007 SW -2.70 40

16( 6). 7-20-83 4480 100 228 L10 ' IH 39 L1.719 L10 lH 1.421 l 39 1.153 1.495 1.007 NE -2.62 42 j 17 8-17-83 5520 1001 216 . LO6L IJ 46 1.740 L10 IH I 1.436 38 1.154 1.516 1.008 SW -3.11 42

, p _ _l ll ,

\

,_. l i C V

i NOTES: HOT SPOT LOCATIONS ARE SPECIFIED BY GIVING ASSEMBLY LOCATIONS (E.G. H-8 IS THE CENTER-OF-CORE ASSEMBLY), ,

, DINOIED BY THE "Y" COORDINAIE WiiH Tile SEVENTEEN ROWS Of FUEL RODS

! FOLLOWED LETIERED BY A THROUGH THE R ANDPINillE LOCATION {X" COORDINAIE DESIGNATED IN A SIMILAR MANNER).

IN THE "Z" DIRECTION THE CORE IS DIVIDED INTO 61 AXI AL PolNTS STARTING FROM THE TOP OF THE CORE.

s

( 1). F-Q(T) INCLUDES A TOTAL UNCERTAINTY OF 1.05 X 1.03. .

4 ( 2). F-DH(N) INCLUDES A MEASURLMENT UNCERTAINIY OF 1.04.~

j ( 3). F(XY) INCLUDES A TOTAL UNCERTAINTY OF 1.05 X 1.03.

( 4). QPTR - QUADRANT POWER TILT RAllo.

I j ( 5). MAPS 8 AND 9 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

3

( 6). MAPS 14 AND 15 WERE TAKEN FOR INCORE/EXCORE CAllBRAT10N.

j

?

I 1

f 1

i , __ -

-- _ -.- - _ . . . - - = _ . -.

, TABLE 4.1 (CONT.)

l BURN l F-Q ( T ) HOI F-OH(N) HOT CORE F(Z) ~~[

l UP l BANK CHANNEL FACTOR CHNL. FACTOR MAX QPTR AXIAL NO.

MAP l DATE MWO/ PWR D F(XY) : OFF of NO. MTU (%). STEPS AXlAL AX4AL MAX l SET THIM ASSY PIN PolNT F-Q(T) ASSY PIN f-DH(N) PolNT F(Z) MAX LOC (%) BLES 1

18 9-20-83 6834 100 214 K05 Hi, 48 1.757 L10 IH 1.435 47 1.169 1.510 1.008 SW -6.29 48 23( 7) 11-16-83 7963 100 216 LIO IH 47 :1.778- L10 ill 1.443 47 1.171 1.518 11.011 SW -5.54 39 24 12-15-84 9023 100 ' 218 L10 . lH 47 1.767 L10 t il 1.442 47 1.165 1.517 1.007 SW -5.26 40 25 2-15-84 10170 100 226 L10 IH 48 1.750 L10. lH 1.450 47 1.147 1.522 1.007 SW -3.96 39 28( 8) 3- 7-84 10965 100 225 L10 lli 47 1.763 L10; IH 1.444 48 .1.163 1.513 1.008 SW -5.28 40 i 29 4- 9-84H12241' 100 222 L10 til 48 1.739 L10; IH 1.435 53 1.162 1.506 1.005 SW, -4.84 , 40

'30 4-16-84 l12511. 100 228 L10 IH 48 1.768 L10 til 1.437 53 1.180 1.509 1.006 SW -5.62 40

'l _ iI _I ._ _

( 7). MAPS 19, 20, 21, AND 22 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

1

( 8). MAPS 26 AND 27 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

, Ii j

i l

5 I

Figure 4.1 NORTH ANNA UNIT 1 - CYCLE 4 ASSEMBLYWISE POWER DISTRIBUTION N1-4-07 0 P N R L K J N $ F E O C S A

. MEAsupt0 . . 0.50 . 0.82 . 0.49 . MEASUNED . 1

. PCT 01FFE#t E E. . 5.8 . 5.4 . 3.6 . .PC7 01FFERENCE.

0.34 . 0.92 . 1.12 . 1.12 . 1.12 . 0.93 . 0.34 2

. 1.4 1.0 . 2.4 2.5 . 2.5 . 1.1 . 1. 3 .

. 0.33 . 8.07 . 1.12 . 1.2 0 . 1.20 . 1.19 . 1.12 . 0.84 . 0.M . 3

. -0.2 . -0.4 . -0.5 . 8.2 . 9.2 . -0.4 . 0.7 . 0.1 . 1.6 .

. 0.33 . 0.84 . 1.07 . 1.17 . 1.25 . 1.11 . 1.23 . 1.16 . 1.07 . 8.42 . 4.34 4

. -1. 4 . -1. 5 . -0.8 . 4. 3 . 0.5 . 8.4 . -1.0 . -1.5 . -0.5 . 0.6 . 3.8 .

. 0.33 . 0.84 . 1.05 . 1.10 . 1.21 . 1.06 . 1.19 . 1.04 . 1.21 . 1.11 . 1.87 . 0.93 . 8.36 . 5

. 4.0 . -4.0 . -2.6 . -2.0 . -1.2 . 8.0 . -0.1 . -1.4 . -1.5 . -1.4 . -0.5 . 6.0 . 6.0 .

. 8.49 . 1.18 . 1.15 . 1.29 . 1.19 . 1.26 . 1.21 . 1.25 . 1.19 . 1.22 . 1.17 . 1.16 . 0.97 6

. -4.4 . - 2.4 . -2. 2 . 2.1 . -0. 7 . 8.3 . 0.6 . -0.2 . -4. 3 . -0.8 . -0.4 2.4 . 6.8 .

. 8.47 . 1.89 . 1.19 . 1.23 . 1.04 . 1.24 . 1.21 . 1.18 . 1.21 . 1.25 . 1.05 . 1.25 . 1.20 . 1.10 . 9.44 . 7

. 0. 7 . -0.1 . -0.1 . -0. 9 . -1. 7 . -1. 0 . -0.1 . 0.4 . -0. 0 . -0. 8 . -0. 7 . -0. 0 . 0.5 . 0.9 . 1.3 .

. 0.74 . 1.10 . 1.20 . 1.21 . 1.20 . 1.21 . 1.17 . 1.24 . 1.18 . 1.21 . 1.19 . 1.21 . 1.21 . 1.10 . 0.76 . 8

, . 0.6 . -0.8 . 4.3 . 8.4 0.7 . 0.6 . 4.2 . 0.9 . 0.5 . 8.5 . -0.3 . 0.0 . 0.5 . 8.4 . 1.3 .

. 0.47 . 1.09 . 1.30 . 1.25 . 1.87 . 1.26 . 1.21 . 1.18 . 1.21 . 1.26 . 1.05 . 1.23 . 1.20 . 1.10 . 4.44 . 9

. 0.5 . 0.1 . 0.1 . 0.5 . 0.9 . 0.6 . 0.0 . 0.5 . 9.2 . 8.1 . -1.1 . -1.3 . -0.0 . 0.9 1.2 .

. 0. 91 . 1.12 . 1.18 . 1. 2 3 . 1.2 8 . 1. 26 . 1. 21 . 1. 25 . 1.19 . 1.10 . 1. L5 . 1.11 . e . 92 . 18

. -0.5 . -0.5 . 0.2 . 0.6 . 4.4 . 0.0 . 0.5 . -0.4 . -0.9 . -1.9 . -2.6 s -1.0 . 0.9

. 0. M . 0. 44 . 1. 0 7 . 1.12 . 1. 2 2 . 1. 05 . 1.19 . 1. 04 . 1. 2 0 . 1.18 . 1. 05 . 0. 06 . 8. 34 11

. 0.6 . e . 5 . -0. 4 . -1.1 . -4. 7 . -4. 4 . -e .4 . -1. 9 . -2. 0 . -2.4 . -2.1 . -1. 4 8.2 .

. 0.34 . 0.41 . 1.06 . 1.16 . 1.24 . 1.20 . 1.24 . 1.16 . 1.06 . 0.00 . 4.33 . It

. 1.6 . 8. 3 . -1.1 . -1. 8 . -4. 4 . -4. 4 . -0.6 . -1.3 .' -1.4 . -1.9 . -1.6 .

. 0.34 . 0.89 . 1.13 . 1.19 . 1.21 . 1.21 . 1.14 0.46 . 0.33 . 13

. 1.4 . 1.9 0.5 . -0.4 0.5 . 0.8 . 1.0 . -1.4 . 1.4 .

. 0.34 . 0.99 . 1.13 .'1.13 . 1.18 . 0.95 . 8.34 14

. 1.9 4.1 . 3.3 . 2.9 0.9 1.2 . -0.1 .

. 0.50 . 0.81 . 8.44 . 15

. 6. 3 . 4.5 . 2.5 .

STMSASO OtVIAT1tD8

  • 1.341 AYtWASE PCT. 01FFt9f E t 8 1.2

SUMMARY

MAP NO: N1 7 DATE: 3/24/83 POWER: 100%

CONTROL ROD POSITIONS: F-Q(T) = 1.765 QPTR:

D BANK AT 221 STEPS F-DH(N) = 1.393 NW 0.995 NE 1.009 F(Z) = 1.176 SW 1.004 SE 0.992 F(XY) = 1.513 BURNUP = 305 MWD /MTU A.O = -1.16(%)

22

Figure 4.2 NORTH ANNA UNIT 1 - CYCLE 4 ASSEMBLYWISE POWER DISTRIBUTION N1-4-13 0 P N M 1 K J H $ F E D C B A

. MEASUBtB . . 0.45 . 0.70 . 0.44 MEASURED

. . 1

. PCT 01FFERENCE. 0.4 . 0.7 . -0.1 . . PCT DIFFt#ENCE.

. 0.37 . 0. 09 . 1. D4 . 0.97 . 1.0 3 . 0.07 . 0.37 . 2 1.1 . 1.3 . 1.4 1.2 . 0.5 . -1.2 . 0.9 .

. 0.39 . 0.97 . 1.18 . 1.11 . 1.04 . 1.10 . 1.16 . 0.97 . 0.40 3

. 0.8 . 0.0 . 0.9 0. 3 . 9.2 . -0.6 . -1.0 . 0.5 . 3. 3 .

. 0.34 . 0.09 . 1.20 . 1.19 . 1.27 . 1.12 . 1.26 . 1.17 . 1.20 . 0.90 . 0.39 4

. -1.0 . -0.2 . 0.6 . 0.8 0.4 . 0.2 . -0.6 . -0.3 . 0.9 1.5 . 2.9

. 0.36 . 0.93 . 1.10 . 1.16 . 1.31 . 1.03 . 1.11 . 1.03 . 1.30 . 1.16 . 1.20 . 0.99 . 0.34 .

-2. 9 . *2. 9 . -0. 9 . -0.1 .

5

. 9. 2 . -0. 4 . -1. 0 . -1. 6 . -0. 7 . -0. 2 . 0.6 . 2.0 . 4.4

. 0.07 . 1.16 . 1.17 . 1.30 . 1.10 . 1.29 . 1.14 . 1.20 . 1.17 . 1.31 . 1.14 . 1.20 . 0.92 .

. -1. 3 . -1. 3 . *1. 0 . -0.6 . -0.1 .

  • 0. 2 .

6

-0. 2 . -0. 9 . -0. 6 . -0.1 . 0.4 . T. 0 . 4.5 .

. 0.45 . 1.02 1.10 . 1.25 . 1.02 . 1.20 . 1.16 . 1.16 . 1.16 . 1.29 . 1.03 . 1.25 . 1.10 . 1.02 . 0.45 . 7

. 6.1 . -0.4 . -0. 3 .

  • 1.1 . -1. 9 . *1. 5 . +0. 0 . -0. 5 . = 0.4 . -0. 4 . -0. 4 . -1. 2 . -0. 7 . -0. 9 0.6 ,

0.69 . 0.96 . 1.07 . 1.11 . 1.11 . 1.14 1.16 . 1.29 . 1.16 . 1.14 . 1.11 . 1.10 . 1.07 . 0.90 . 0.72 . 8

. -1.0 . 0.5 . -0.4 . -9.4 . -0.5 . -0.5 . +0.6 . 8.1 . -0 2 . -0.3 . -0.6 . -1.3 . -0.4 . 1. 3 . 3.6 .

.....................................................................................................+...

. 0.45 . 1.02 . 1.10 . 1.26 . 1.04 . 1.29 . 1.16 . 1.16 . 1.17 . 1.29 . 1.03 . 1.25 . 1.10 . 1.04 . 0.44 . 9 0.0 . -0.5 . -0.5 . *0.4 . -0.2 . -0.4 . -0.6 . 0.1 . -0.3 . -0.4 . -0.8 . -1.6 . -0.6 . 1. 3 . 2.4 .

. 0.64 . 1.17 . 1.19 . 1.32 . 1.10 1.36 . 1.14 . 1.20 . 1.17 . 1.30 . 1.17 . 1.17 . 0.91 . 10

. -0.1 . -0.1 . 0.6 . 1.0 . 0.4 . -1.1 .

  • 0. 5 . -0. 6 . -0. 7 . -1. 0 . -0. 7 . -0. 2 . 3.1 .

. 0.34 . 0.99 . 1.21 . 1.16 . 1.30 . 1.03 . 1.11 . 1.03 . 1.30 . 1.15 . 1.19 . 0.96 . 0.37 . 11

. 3.5 . 2.5 . 1.4 0.4 . *0.4 . *1.1 . *1.1 . *1.5 . -1.1 . *1.1 . -0.4 . *0.1 . 0.9

. 0.40 . 0.91 . 1.19 . 1.17 . 1.25 . 1.11 . 1.25 . 1.17 . 1.10 . 0.80 . 0.34 . 12

. 5.2 . 2.4 0. 3 . -0. 3 . 0. 9 . -0. 9 . 1. 0 . =0. 9 . -1.1 . -0. 3 . 0.2 .

. 0.44 . 1.00 1.19 . 1.10 . 1.08 . 1.11 . 1.18 . 0.95 . 0.34 . 13

. 4.6 . 4.0 . 1.5 . *0.6 . -0.0 . 9.1 . 0.2 . -1.1 . 0.0

. 0.38 0.92 . 1.05 . 0.98 . 1.03 . 0.00 . 0.37 . 16

. 4.0 . 4.4 2. 3 . 1.7 . 9.2 . 0.3 . -0.6 .

. 0.47 . 0.71 . 0.45 . 15

. 4. 7 . t.9 1.1 .

S7AW ABO OtVIAT1tte a 1.044 AVf0ASE PCT. 01FFERENCE 5 1.1

SUMMARY

MAP NO: N1-4-18 DATE: 9/20/83 POWER: 100%

CONTROL ROD POSITIONS: F-Q(T) = 1.757 QPTR:

D BANK AT 214 STEPS F-DH(N) = 1.435 NW 0.997 NE 1.001 F(Z) = 1.169 SW 1.008 I SE 0.994 F( XY) = 1.510 BURNUP = 6834 MWD /MTU A.O = -6.29(%)

23

i Figure 4.3 NORTH ANNA UNIT 1 - CYCLE 4 ASSEMBLYWlSE POWER DISTRIBUTION N1-4-30 B p M M L K J M S P t D C B A

. =As-to . . 0.47 . 8.n . 0.47 . = Asuneo . t

.PC7 O!FFERENCE. . 2.6 . 2.6 . 1.9 .PC7 O!FFERENCE.

. 0.41 . 0.07 . 1.03 . 0.96 . 1.03 . 0.04 . 0.41 . 1

. 5.1 . -0. 7 . 1.0 . 1.0 . 1.0 . 1.1 . 3.5 .

. 0.42 . 1.02 . 1.17 . 1.07 . 1.01 . 1.04 . 1.20 . 1.03 . 0.44 3

. 1. 9 . 1. 5 . -2. 2 . =0. 7 . -0. 7 . 0.1 . 0.5 . 2.4 6.0 .

. 0.44 0.93 . 1.24 . 1.16 . 1.27 . 1.04 . 1.26 . 1.16 . 1.25 . 0.94 . 0.43 . 4

. 5.1 . 0.4 . 0.6 . -0.2 . 0.4 . 0.7 . -0.4 . -0.1 . 1.1 . 1.4 . 3.6 .

. 0.39 . 1.00 . 1.21 . 1.13 . 1.31 . 1.03 . 1.00 . 1.02 . 1.31 . 1.14 . 1.20 . 1.03 . 0.42 .

9. 2 . -0. 5 . -4. 0 . -1. 9 . 5

. -0. 9 0.5 . 4. 3 . -0.9 . -0.6 . 1.2 . -2.4 2.5 . 7.3 .

. 0.64 . 1.20 . 1.15 . 1.29 . 1.16 . 1.29 . 1.10 . 1.20 . 1.16 . 1.29 . 1.13 . 1.20 . 0.91 .

9.2 . 0. 2 . -1.2 . -2. 0 . -0. 7 . -0.1 . 0.1 . -0. 8 . -0. 5 . -2. 2 . -2. 7 .

6 0.4 3.6 .

. 0.46 9.2 .

. 1.02 . 1.00 . 1.24 . 1.00 . 1.26 . 1.12 . 1.13 . 1.12 . 1.20 . 1.01 . 1.23 . 1.06 . 1.01 . 0.46 .

9.2 . 9. 2 . -1. 0 . -2.4 . -2.1 . -1. 2 . =0. 7 . -0. 4 . -0.5 . -2.1 . -2. 3 . -1. 5 .

7

-0. 7 . -0.1 .

. 0.69 . 0.95 9.2 .

1.04 . 1.08 . 1.07 . 1.10 . 1.13 . 1.38 . 1.13 . 1.09 . 1.05 . 1.05 . 1.02 . 0.97 . 0.72 .

0. 2 . -0. 2 .

4

. 0.2 . -0. 5 . -0.6 . -0.4 . -0. 3 . -0. 9 . -1. 0 . -2. 9 . -2. 2 . -1. 5 . 2.0 4.1 .

.. 0.45 . 1.02 . 1.07 . 1.26 . 1.03 . 1.27 . 1.10 . 1.12 . 1.11 . 1.27 . 1.02 . 1.26 . 1.00 . 1.05 . 0.44 .

-0.4 . 0. 4 . -0.4 . -0. 4 . -0. 2 . -1. 2 . - 3.1 . -1. 6 . -1.4 . -1.6 . -1.1 . -0.4 9

0.1 . 2.7 . 5.0 .

. 0. 4 7 . 1.190.4

. 1.17 . 1. 34 . 1.16 . 1. 25 . 1. 04 . 1. 26 . 1.15 . 1. J1 . 1.17 . 1. 21 . 0. 91 . 10

. -0.4 . 0.6 . 1. 2 . =0. 3 . -2. 9 . -2. 0 . -2. 2 . -1. 4 . -1.1 . 0.7 . 0.9 4.3 .

. 0.40 . 1.D4 . 1.26 . 1.16 . 1.30 . 1.00 . 1.05 . 1.00 . 1.30 . 1.15 . 1.24 . 1.02 . 0.40 . 11

. 2.9 . 2.9 . 2.2 . 0. 9 . -1. 4 . -2. 6 . -2. 6 . - 3. 0 . -1. 4 . -0. 4 0.6 . 0.7 . 1. 3 .

. 0.44 . 0.95 . 1.25 . 1.16 . 1.24 . 1.06 . 1.24 . 1.15 . 1.23 . 0.92 . 0.42 .

. 6.2 . 3.6 . 0. 9 . -0. 7 . *1. 4 . -1. 7 . -1. 6 . =0.4 . -0. 5 . 6.6 . 0.2 .

It

. 0.44 . 1.07 . 1.22 . 1.06 . 1.02 . 1.07 . 1.20 . 1.01 . 0.42 13

. 6.2 . 6.2 . 2.0 . -1.3 . -1.2 . -0.2 . 0.1 . 8.1 . 0.2 .

' . 0.42 . 0.93 . 1.05 . 0.97 . 1.02 . 0.60 . 0.39 14 l

. 6.2 . 4.4 3.2 . 3.0 . -0.2 . 8.1 . 8.1 .

. 0.49 . 0.74 0.49 15

. 6.6 . 6.6 6.6 .

STAf@ANO OtVI A71(pg a 1.672 AVtWAGE PC7. O!FFtWENCE e 1.7 I

l

SUMMARY

l .......

l MAP NO: N1-4-30 DATE: 4/16/84 POWER: 100%

l CONTROL ROD POSITIONS: F-Q(T) = 1.768 QPTR:

D BANK AT 228 STEPS F-DH(N) = 1.437 NW 0.997 NE 1.002 F(Z) = 1.180 SW 1.006 SE 0.995 F(XY) = 1.509 BURNUP = 12511 MWD /MTU A.O = -5.62(%)

or A .

Figure 4.4 HOT CHANNEL FACTOR NORMALIZED OPERATING ENVELOPE 1.2 (6.0, 1.0) 1.0- - , (10,91, o,94).

K , a e 0.8 Z

\

N

  • O R

M 0.6 .

A ,

L 1

Z E

0 )

F 0.4 (12.0, 0.45).

O e

Z 0.2 '

O.0 ,

0 2 4 6 8 10 12 CORE HEIGHT IFil BOTTOM TOP 25

Figure 4.5 NORTH ANNA UNIT 1 - CYCLE 4 HEAT FLUX HOT CHANNEL FACTOR, F (Z)

N1-4-07 1.s .

I.0 e m

m -

N -

v .

N7 -

XXXXX

=

XX

=

XXXXXX X X X XX XXXX X X X X g

  • XX X X Q
  • X X X XXXX X X H I.5 + X U = XXX X
  • C . X X A . X X

X

2
  • K . X XX

$ - X I.0 +

X w -

C - X

= .

X M

D .- X X A -

g X

.X H =

<C 0.5

  • l W -

I =

1 .

i .

0.0 +

1.....I....I....I....I....I....I....I..

el 55 50 45 40

. I... I. . .I. ..I. ..I IS 30 IS 10

  • IS 30 5 I 80TTan OF Coat ,

TOP OF COWE AXIAL POSITION (NODES) 26 l __ _ _ - _ . . _. _ - - -- - - _ - - -

Figure 4.6 NORTH ANNA UNIT 1 - CYCLE 4 HEAT FLUX HOT CHANNEL FACTOR, F[(Z)

N1-4-18 2.5 .

m

^

N

  • V .

b CT

  • MMMMMM MM b
  • MM

" MMMM MMM M MMMMMM g

  • M M M M XMMX Q = M M M XX
p. 1.5
  • M U = X X X XyXX

. X m< X X

X, X

E - X s - XX c ...: ",

g M o -

. M M -

h-m

  • 8 XX t;

W 2: -

- - e..

n. . .

AX1AL POSITION (NODES) 27

t Figure 4.7 NORTH ANNA UNIT 1 - CYCLE 4 T

HEAT FLUX HOT CHANNEL FACTOR, Fg(Z)

N 1 30 2.5 +

I.0 +

m

  • N -

V .

N7 - XXXX XXXX A - xx

. X XX X XXMX g

  • X XX XXX

. O - X X X XXX XXXXXX XXMXX 1.5

  • M X X

. M X X 4 -

X X

=

X X

=

X

= X '

M Z

  • X Z .

$ -X X U 1.0

  • M p =

X X O *

= -

X X .

f -

x  :

s -

Es.1 0.5 +

Z .

0.0 +

!... .I....I....I....Z....I....Z....Z....I....Z....!....I...!

61 55 50 45 40 35 30 IS 10 15 10 5 1 00TTOM OF Cort TCP OF Cost AXIAL POSITION (NODES) 28

Figure 4.8 NORTH ANNA UNIT 1 - CYCLE 4 MAXIMUM HEAT FLUX HOT CHANNEL FACTOR, FQ s P VS AXIAL POSITION FQ = P LIMIT .-

a MAXIMUM F0 m P 2.4 ,

5 2.2 N-2.0 N '

1.8

      • **** "* ,, m* ,,_ ,. "***,

k l.6

"**e * \

. .. \

1.4

  • \
~~

\

12

\

.\

1.0 08 ,

0.6 0.4 0.2 0.G-61 55 50 45 40 35 30 25 20 15 10 5 1 AXIAL POSITION (NODE)

BOTTOM OF CORE TOP OF CORE 29

Figure 4.9 NORTH ANNR UNIf 1 - CYCLE 4 MAXIMUM HEAT FLUX HOT CHANNEL FACTOR, F-Q VS. BURNUP

- TECH SPEC LIMIT X MEASURED VALUE 2.4 2.3 M

A 2.2 X

I M

U 2 .1 0 .

H E 2.0 A

T F 1.9 L

U X

1.8 x )

y X _ >:

X '

X T x x x 1.7 C

H A

N 1.6 N

E L

1.5-F -

A C

T 1. 4 0

~

R .

1.3 1

2-_

0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MWD /MTU1 30 .

Figure 4.10 NORTH ANNA UNIT 1 - CYCLE 4 ENTHALPY RISE HOT CHANNEL FACTOR, F-OH(N) VS. BURNUP

- TECH SPEC LIMIT X MERSURED VALUE 1.60 '

1.55 E 1.50 N '

T H

A '

L 1.45 '

P '

y ): >:

x x :c x

R X I 1.40' s S - X E '

H 0 1.35 T ,

C H

R 1.30 N

N E

L 1.25 '

F R -

C T

0 1 20-R 1 15._

1 102 i

0 2000 4000 6000~ 80b0 10000 12 BOO 140b0 CYCLE BURNUP (MWD /MTU) 31

Figure 4.11 NORTH ANNA UNIT 1 - CYCLE 4 l

TARGET DELTA FLUX VS. BURNUP 10 8

6, T

A R

G 4 E

T O

E 2 L

T G -

F 0 L 3 U . ,

X I -2 N 3 3

^ ^

P E

R -4  :.

C E

^

N T 2, a z, A

-6 6

-8 .

0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MH0/MTUI 32

Figure 4.12 I

NORTH ANNA UNIT 1 - CYCLE 4 CORE AVERAGE AXIAL POWER DISTRIBUTION N1-4-07 i.3 F

Z

= 1.176 A. O. = -1.2 1.2 +

=

XXMMMM MMMXAX X

=

XXXX M M XXXX

= XX X X X

  • . X X X 'MXX

=

M X X

= M X X

  • X XX X

. M M

  • X a 0.9 .+ M

.C -

X I4 =

s . ., M X

a .

< . X .

5 e

=

M

. gg 0.6 +

  • K

- x n

w

- X

~ ..

=

Ca

  • M X x

0.3 .+

0.0 +

  • 00 Tion of Cont TOP 0F Cone AXIAL POSITION (NODES) 33

Figure 4.13

. NORTH ANNA UNIT 1 - CYCLE 4 CORE AVERAGE AXIAL POWER DISTRIBUTION N1-4-18 i.s .

F = 1.169 Z

A. O. = -6.3 .

1.2 +

. xxxxx

. . XX XXMXXX

. MMX X XXXMMX

. X X X X XXXX M MM

['

x x M XX X XXM x

- x x X x e 0.9 a - = x t.iJ N

>s -* xx a -

X o -

x Z 0.6

  • X

'v .

N

x

.K x

w  : xx 0.3 +

0.0 +

...;,....g....;,c...;,..  ;,. . . .;,. TOP OF CORE 801 TOM OF CostE AXIAL POSITION (NODES) 34

. . _ . . _ _ . . . . __. ~_ _ . _ . _. _ . _ _ _ _ _ _ ~

f

,f 3 -

$/

t

(

Figure 4.14 5

1 NORTH. ANNA UNIT 1 - CYCLE 4

, , CORE AVERAGE AXIAL POWER DISTRIBUTION f

N1-4-30 1

1.5 .+ .'

F.,

u

= 1.180 < >

A. O. = -5.6

. i. , 4

.t i 1.2 +

>=, , XXX XXX X XXX

=.

I

> X X i X XX XXXX =

. X X- XXXXXX XXXX

. X X

X X X X X X XXXX X

. X X X

= X X X j m 0.9 + 4 X

I

.] i i . XX u .*

X

< 1

  • m .

J =

4 . i X

  • i kO .

2; 0.6 + X X v . '

  • m .= X N .

K v .

X 63 '. I j.

6 ,

. I '

. / i { '

, j .

1 0. 3 .* - s

).

. 1,

> s g

. ) >

= 1 ,

3

. t ,

> 5, I (

  • I 1 0.0 + 'l
8. ..l ....l ...l ....l l ...*%..**I . *
  • I + * *
  • l* I * * * * * *I
  • I 40 . . .

15 * *

  • 1 61 SS 50 45 35 30 25 20 to 3 1 (J gottope OF CORE i / 4

' TOP OF CORE i

r AXIAL POSITION (NODES) .

..g

' <?

'a

.4

)

t l

h-r s 1

l 4

  • +

y 35 t $

4 t

'i \

. _ . , , ., , ,ln - - , _ _ _ .-~ .,, _ _ . . . _ - . ._

Figure 4.15 NORTH ANNR UNIT 1 - CYCLE 4 CORE RVERAGE RXIRL PERKING FRCTOR, F-Z VS. BURNUP

_y '_i.4 ~

j , 3

')

13

. .' Ll << -

\ ', :

R .

x .

-1 R

L -

P E

R K 1.2 I

N G a ^

A 6 2 ,

F,, 4

i. ,

3 2 ,

a R -4 6 A C I 6 T 1 0 1 i R s E 11 ,

1.0-i O 2000 4000 ~6000 8000 10000 12000 14000 CYCLE BURNUP (MH0/MTU)

, 36 -

V Section 5 PRIMARY COOLANT ACTIVITY FOLLOW Activity levels of iodine-131 and 133 in the primary coolant are important in core performance follow analysis because they are used as indicators of defective fuel. Additionally, they are also important with respect to the offsite dose calculation values associated with accident analyses. Both I-131 and I ,133 can leak into the primary coolant system

. throught a breach in the cladding. As indicated in the North Anna 1 Technical Specifications, the dose equivalent I-131 concentration in the primary coolant was limited to 1.0 pCi/gm for normal steady state operation. Figure 5.1 shows the dose equivalent I-131 activity level history for the_ North Anna 1, Cycle 4 core. The demineralizer flow rate averaged 120 gpm during power operation. The data shows that during Cycle 4, the core operated substantially below the 1.0 pCi/gm limit during steady state operation (the spike data is associated with power transients and unit shutdown). Specifically, the average dose equivalent I-131 concentration of 0.081 pCi/gm is equal to 8*. of the Technical 4

Specifications limit.

The ratio of the specific activities of I-131 to I-133 is used to characterize the type of fuel failure which may have occurred in the reactor core. Use of the ratio for this determination is feasible because I-133 has a short half-life (approximately 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />) compared to that of I-131 (approximately eight days). For pinhole defects, where the diffusion time through the defect is on the order of days, the I-133 37

decays out leaving the I-131 dominant in activity, thereby causing the ratio to be 0.4 or more for a demineralizer flow rate of 120 gpm. In the case of large leaks, uranium particles in the coolant, and " tramp" uranium *, where the diffusion mechanism is negligible, the I-131/I-133 ratio will generally be less than 0.08 for a demineralizer flow rate of 120 gpm. Figure 5.2 shows the I-131/I-133 ratio data for the North Anna 1, Cycle 4 core. These data generally indicate there were probably pinhole defects in the fuel used during Cycle 4.

  • " Tramp" uranium consists of small particles of uranium which adhere to the outside of the fuel during the manufacturing process.

38

9 Figure 5.1 NORTH ANNA UNIT 1 -

CYCLE 4 00SE EQUIVALENT I-131 vs. TIME

~

O

~

W m

~

o 8 e g

[ g hfgicAtefEciricAj;0Nsthir ee: e  ! e

, ceom g 8 e

- oo o

. e ce o e e

~ g 8 o O

_ 8 e e 59 8 .me o ,h Junklige, 5:

e 8-4M[NU $

o e e

V&

e e

a x -

e %e o

%8 u

- 'O @s e e

r_ -

e

?

.* e1

' o

8 o

7 0 0 O

~

m

~

o g F- "

y n F r.

100, l'

i 1 y

~.

50 g

/ =

0 E

~ l.

i i i i i i i i i i i i i i i , i JAN FEB MAR APR MAY JUN jut AUG sEP OCT NOV DEC JAN FEB MAR APR MAY 1983 1984 39 l

l

~ -~

Figure 5.2 NORTH ANNA UNIT 1 -

CYCLE 4 I-131/I-133 ACTIVITY R AT I O vs. TIME 8

4 e l e

o O

N O O

O f

a" e

o O O ta 8 ci O

>N g n

[ O bl O u

C O

O Cr O e O

M ,,' db

~

O O -

2 eO e ,0 0 O

N @ QO O O

~ O m2 -

e @I O em O

e-e e I ac Ob O

,hO

~

O C 1 O O 00 p o $

kB , E b. e , k, M

C

,hf ~ iWQ

/

-t F ' - = -

i-- 100, 1 r 2

50 g

,II , ,

l

,,,,,,,o!

f JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV OEC JAN FEB MAR APR MAY I

1983 1984 40

1 Section 6 CONCLUSIONS i

j The North Anna 1, Cycle 4 core has completed operation. Throughout this cycle, all core performance indicators compared favorably with the design predictions and all core related Technical Specifications limits were met with significant margin. No abnormalities in reactivity power distribution, or burnup accumulation were datected. In addition, the mechanical integrity of the fuel has not changed significantly titroughout Cycle 4 as indicated by the radiciodine analysis.

t 5

41

Section 7 REFERENCES

1) C. A. Ford, " North Anna Unit 1, Cycle 4 Startup 'hysics Test Report," VEP-NOS-2, March, 1983.
2) North Anna Power Station Unit 1 Technical Specifications, Sections 3/4.1 and 3/4.2.
3) T. K. Ross, "NEWTOTE Code", VEPC0 NFO-CCR-6 Rev-8, April, 1984.
4) R. D. Klatt, W. D. Leggett, III, and L. D. Eisenhart,

" FOLLOW Code," WCAP-7482, February, 1970.

5) W. D. Leggett, III and L. D. Eisenhart, "INCORE Code,"

WCAP-7149, December, 1967.

42 .

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