ML20151N567

Cycle 5 Core Performance Rept

ML20151N567
Person / Time
Site:	North Anna
Issue date:	11/30/1985
From:	Ford C, Iannucci J, Mann B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20151N565	List: ML20151N560 ML20151N567
References
VP-NOS-20, NUDOCS 8601030011
Download: ML20151N567 (49)

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North Anna Unit 1 Cycle 5 Core Per onnance Report Nuclear Operations Depa" Intent l'ir;tiln/a Electric and Potver Coinpany h $6 6' Ikl '( ) g D i{

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VP-NOS-20 NORTH ANNA UNIT 1, CYCLE 5 CORE PERFORMANCE REPORT by C. A. Ford and J. V. Iannucci Reviewed: Approved:

73 0 K B. D. Mann, Engineer

c. A L C. T. Snow, Superviser Nuclear Fuel Operation Nuclear Fuel Operation Operations and Maintenance Support Subsection Nuclear Operations Department Virginia Electric and Power Company Richmond, Virginia November, 1985

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 COMPANY MAKES NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, NOR SHALL ANY 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 conclusions 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 disclaimers 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

TABLE OF CONTENTS SECTION TITLE PAGE NO.

Classification / Disclaimer . . ...... ....i List of Tables . . ..... ... ... . . . . iii List of Figures . . . ... ....... . . . . iv 1 Introduction and Summary. . . . ..... ... 1 2 Burnup Follow . . . ........... . . . . 7 3 Reactivity Depletion Follow . .

. . .. . . . . 14 4 Power Distribution Follow . ...... . . . . 16 5 Primary Coolant Activity Follow . . ... . . . . 36 6 Conclusions . . . . . ......... . . .. . 40 7 References. ..................41 11

LIST OF TABLES TABLE TITE PAGE NO.

4.1 Summary of Incore Flux Haps for Routine Operation . . . . . . 19 111

LIST CIF 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 Factors ... . . . . . . . .. . . .. . 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 - N1-5-15 . .. . . . . . . . 21 4.2 Assemblywise Power Distribution - N1-5-23 . . . .. . ... . 22 4.3 Assemblywise Power Distribution - N1-5-34 ..... . . . . . 23 4.4 Hot Channel Factor Normalized Operating Envelope . . . . . . . 24 4.5 Heat Flux Hot Channel Factor, F (Z) - N1-5-15. . . . . . .. . 25 4.6 Heat Flux Hot Channel Factor, F (Z) - N1-5-23. . . .. . . . . 26 4.7 HeatFluxHotChannelFactor,Ff(Z)-N1-5-34. . . . . . .. . 27 4.8 Maximum Heat Flux Hot Channel Factor, Fq*P, vs.

Axial Position . . . . .......... . . .. . . . .. . 28 4.9 Maximum Heat Flux Hot Channel Factor, Fq , versus Burnup. . . . 29 4.10 Enthalpy Rise Hot Channel Factor, F-DH(N), versus Burnup . . . 30 4.11 Target Delta Flux versus Burnup . . . . . . . . . . . . . . 31 iv

LIST OF FIG RES CONT'D ,

FIGURE TITLE PAGE NO.

4.12 Core Average Axial Power Distribution - N1-5-15 . . . . . . . 32 4.13 Core Average Axial Power Distribution - N1-5-?3 . . . . . . . 33 4.14 Core Average Axial Power Distribution - N1-5-34 . . . . . . . 34 4.15 Core Average Axial Peaking Factor, FZ , versus Burnup . . . . . 35 5.1 Dose E;uivalent I-131 versus Time . . . . . . . . . . . . . 38 I 5.2 I-131/I-133 Activity Ratio versus Time . . . . . . . . . . 39 v

I Section 1 INTRODUCTION AND

SUMMARY

On November 4, 1985, North Anna Unit I completed Cycle 5. Since the initial criticality of Cycle 5 on September 25, 1984, the reactor core produced approximately 79 x 10' MBTU (13,398 Megawatt days per metric ton of contained uraniam) which has resulted in the generation of approximately 7.8 x 10' W1Ir gross (7.4 x 10' n'lir net) of electrical energy. The purpose of this report is to present an analysis of the core performance for routine operation during Cycle 5. The physics tests that were performed during the startup of this cycle were covered in the North Anna Unit 1, Cycle 5 Startup Physics Test Report and, therefore, will not 2

be included here.

The fifth cycle core consisted of five batches of fuel. The North Anna 1, Cycle 5 core loading map specifies 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 barnup symmetry and proper batch burnup sharing, thereby ensuring that the fuel held over for the next cycle will be compatible with the new fuel that is inserted.

1

1 s

Reactivity depletion is monitored to detect the existence of any abnormal s

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 Specifications2 limits thereby ensuring that adequate margins to linear power density and criticol 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 5 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 i0.27% with the burnup accumulation in each batch deviating from design prediction by less than 2.1%.

2. Reactivity Depletion Follow ,The critical boron concentration, used to monitor reactivity depletion, was consistently l within i0.42% AK/K of the design prediction which is well within the i1%

i i

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

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

2 o

4. Primary Coolant Activity Follow -

The average dose equivalent iodine-131 activity level in the primary coolant during Cycle 5 was approximately 3.8 x 10 -2 pC1/ge. This corresponds to 3.8% 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.

1 I

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Figuf e 1. i NORTH ANNA UNIT 1 - CYCLE 5 CORE LOADING MAP R P N M L M J H 0 F E D C S A E37 F23 E12 E54 F07 W 'T $60 - F35 [22 I2DP 12DP 2 W W ciO 16P W W 16P W cs4 Cos W 16P 3 W F39 C30 W W F63 C2e W G34 F2% W 16P 20P $$ 20P 16P 4 W W G24 W W W W W C42 F47 W W [25 16P 20P 12DP 20P 120P 20P 16P 5 W W 16P W W 20P W W W cis W W rea W F46 16P 16P 20P 16P 6 W Ssa W G4 W W W W W c3: W c3e W s61 E63 12DP 20P 12DP 16P 16P 16P 12DP 20P 120P 7 W W W 16P W W 042 W F40 W 04) C56 F49 Col W F64 20P 16P 16P 20P SS 16P a W W 120P W W W C16 W G43 W W F 36- W W $$9 E24 20P 12DP 16P 16P 16P 120P 20P 12DP 9 P 6 P 10 W W C51 16P

' W W W W #60 W W c32 c44 W 20P 12DP 20P 12DP 20P 16P 11 W W W 16P W G46 WW F44 CS2 '- W W 20P SS 20P 16P 12 W W cit 16P W W W W cla 004 16P 16P 13 W W W 12DP W $65 F52 W 120P 14

==> ASSEMBLY ID

==> ONE OF THE FOLLOWINC 15 P N ROOS FUEL ASSEMBLY DESIGN PARAMETERS SUB-BATCH 4A3 5A2 6A2 7A SB INITIAL ENRICHMENT (W/0 U-235) 3.21 3.40 3.59 3.60 3.59 I

ASSEMBLY TYPE 17X17 17X17 17X17 17X17 17X17 l

NUMBER OF ASSEMBLIES 12 20 57 59 9 l FUEL RODS PER ASSEMBLY 264 264 264 264 264 ASSEMBLY IDENTIFICATION D04 D05 E06 E12 F02-F05 G01-G59 S57 S58 D07 D11 E17 E18 F07-F11 S59 S60 l D21 D29 E20 E22 F13-F18 S61 S62 i

D36 D37 E24-E26 F20-F24 S63 S64 D41 D42 E29-E31 F26 F27 S65 D47 D51 E33 E37 F30-F40 E39 E43 F42-F53 E54 E56 F56 E59 E63 F58-F61 F63-F69 4

Figure 1.2 NORTH ANNA UNIT 1 - CYCLE 5 MOVABLE DETECTOR AND THERMOCOUPLE LOCATIONS 8 P N M L K J M C F E D C 8 A MO TC

- 1

~

TC TC MD 1 MD - 2 TC T MO TC no TC TC TC 3

TC MD MD 1 M0 TC 4

MD Mo TC MO TC TC MD C S TC T -

TC MD TC MD 6

TC TC MD MD M0 TC MO M0

,a- MD --

T MD TC TC TC TC TC TC

,a-MO TC TC MO TC e TC Mo T TC MO TC MD 9 T T t TC TC Mb i TC MO TC 10 TC MD TC MO T TC TC MO 11 MD MO TC TC M0 TC M0 TC 12 T T TC TC 13 T i TC Mo TC 14 MD . Movetle Detector TC = Theressouple MD TC TC 15 5

Figure 1.3 NORTH ANNA UNIT 1 - CYCLE 5 CONTROL ROD LOCATIONS A P N M L K J H G F E D C 8 A 180' l

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As-tr..Cd 0, function Number of Clusters Control Bank D 8 Control Bank C 8 Control Bank 8 8 Control Bank A S Shutfown Bank S8 8 Shutdown Sank SA 8 SP ( Spa re Rod Loca tions) 8 6

Section 2 BURNUP FOLLOW The burnup history for the North Anna Unit 1, Cycle 5 core is graphically depicted in Figure 2.1. The North Anna 1, Cycle 5 core achieved a burnup of 13,398 MWD /MTU. As shown in Figure 2.2, the average load factor for Cycle 5 was 86% when referenced to rated thermal power (2775 MW(t)).

Radial (X-Y) burnup distribution maps show how the core burnup is shared among the va'ious r fuel assemblies, and thereby allow a detailed burnup distribution analysis. The NEWTOTE 8 computer code is used to calculate these assemblywise burnups. Figure 2.3 is a radial burnup distribution map in which the assemblywise burnup accumulation of the core at the end of Cycle 5 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 5 operation is also given.

As can be seen from this figure, the accumulated assembly burnups were generally within i4% of the predicted values. In addition, deviation frca quadrant symmetry in the core, as indicated by the burnup tilt factors, was no greater than iC.27%.

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 burnup predictions to be made for use in reload fuel design studies.

Batch definitions are given in Figure 1.1. As seen in Figure 2.5, the batch burnup sharing for North Anna Unit 1, Cycle 5 followed design predictions closely with each batch deviating less than 2.1% from design.

7

Symmetric burnup in conjunction with agreement between actual and predicted assemblywise burnups and batch burnup sharing indicate that the Cycle 5 core did deplete as designed.

i 4

4 l

8 i

1 1

1 Figure 2.1 i

NORTH ANNA UNIT 1 - CYCLE 5 l

CORE BURNUP HISTORY  :

I8000 ,

1 17000 ,

16000-,

15000 l --

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C Y 13000 -

1 C i L 12000 E  :

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U E C 0 E l T V C N 8 R R Y N L G P T V C l 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 TIME (MONTMSI CYCLE 5 MAXIMUM DESIGN BURNUP -

17500 MWO/MTU BURNUP WINDOW FOR CYCLE 6 DESIGN - 13000 TO 14500 MWO/MTU 9

Figure 2.2 NORTH ANNA UNIT 1 - CYCLE 5 '

_ MONTHLY AVERAGE LOAD FACTORS 90 -

80 -

70 -

60 -

50 -

40 -

30 -

20 -

l 5 0 N O J F M A M J J A S 0 N C ,

B R N G C i i i i i i

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E THERMAL ENERGY GENERRT10N IN MONTH (MWHT1

'oao ra"o" =, cia;;iier;;;irievicissirracc;rirs;;;r (EXCLUDES REFUELING OUTRGES) 10 ,

Figure 2.3 i

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Figure 2.4 NORTH ANNA UNIT 1 - CYCLE 5 ASSEMBLYWISE ACCUMULATED BURNUP COMPARISON OF MEASURED AND PREDICTED (1000 MWD /MTU)

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. 0. 31.

401 741 15. 74 l 23.81l 31.64 8 l 42.678 .................. 13

.s. 1 . 291.13.371

.4 34.1..3

. 2.31. 14.7512.728.

..... .. 28.231 2 801. 0. 16.231

. 04.8. 20.761

2. 641..3 82.041 44.1..S.203 13.361* 30.54l l AA87seec71C gPC7 0if Avc I le 36.6S ..~.~ f a-. 0..94i . 14

................ 0. 21sl

. 25.001

0. 29. 8..1 44.13.24 4. 0. 3 384..3

. 29.9e164.8. 12.68

.. . 1 3.t.l. 0. 10882S.39) ...............

... 36.608 iS l eta.m04a0Ocv 1 iS

.iM...l l34.001M.42834.7

.. 0. i.91.

. 0. 10.1..0.

. M...i l Av0 Aes Pc7 I

..O..i.r.r. ..1 .3 3..i A P N N L M J M 0 F E O C 8 A BURNUP SHARING (MW3/MTU) BURNUP TILT BATCH CYCLE 2 CYCLE 3 CYCLE 4 CYCLE 5 TOTAL NW =.+0.10 4A3 9816 15170 0 8394 33379 5A2 0 14643 14613 6522 35777 NE = +0.25 6A2 0 0 14958 13949 28907 7A 0 0 0 16218 16218 SW = -0.08 5B 0 0 0 13263 13263

= 27 CORE AVERAGE 13398 12

Figure 2.5 NORTH ANNA UNIT 1 - CYCLE 5 SUB-BATCH BURNUP SHARING SUS-8RTCH ,

N)/4R3 N1/5R2 SYM80L N1/6R2 NI/7A DIRMONO SQURRE TRlRNGLE N2/SB STAR x 40000 ,

4 36000 ,'

n 1 ~-

_ _: ~

=~ _

-=

v 32000 .: __

, e p -

t = _- ,-

5 "

y U 28000

/ p 8  : s r

~

. / '

8 R - -

j e 2

,A 7 24000' ' /

C y N p 8 #

U 20000' '

R f r N f f

. /

16000' '

M

1. f N

~

/

0 # .

/ -

2 r ./

, M 12000, f f h

/ A i / / -

8000,

• 7 #

- f f

/ /

/ /

4000' *

1. 7 i

A V

, rf

2 7 Od [ ,- 1 0 2000 4000 6000 8000 10000 12000 14000 CYCLE SURNUP MM0/MTU i 13

l 1

Section 3 REACTIVITY DEPLETlON 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 5 core is shown in Figure 3.1. It ce n be seen that the measured data typically compare to within 60 ppm of the design prediction. This corresponds to less than 0.42% AK/K which is well within the 11% 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 5 core depleted as expected without any reactivity anomalies.

14

Figure 3.1 NORTH ANNA UNIT 1 - CYCLE 5 CRITICAL BORON CONCENTRATION VS BURNUP HFP, ARO X MEASURED -

PREDICTED 1800 -

1600-C R

I 1400 T

C

(

1200 B "

0 6

mk ,

0 1000 N

C w

V 800-C E

N%-

" \1 R 600 '-

~>

A T W I Tk K

N 400 P

P  %

g 200'

\

\

N

0. . __

\

0 2000 4000 6000 6000 10000 12000 14000 16000 18000 CYCLE SURNUP (MND/MTUI 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 5 is given in Table 4.1. Power distribution maps were generally taken at monthly intervals 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 was taken at the end of Cycle 5 life. In each case the measured relative assembly powers were generally within 4.5% and the average percent difference was equal to 1.8%. In addition, as indicated by the INCORE tilt factors, the power distributions were essentially symmetric for all cases.

An important aspect of core power distribution follow is the monitoring 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 Cycle 5 Technical Specifications limit on the axially dependent heat flux hot channel factor, F q(Z), was 2.20 x K(Z), where K(Z) is the hot channel 16

factor normalized operating envelope. Figure 4.4 is a plot of the K(Z) curve associated with the 2.20 Fq (Z) limit. The axially dependent heat flux hot channel factors, F 9(Z), for a representative set of flux maps are given in Figures 4.5 through 4.7. Throughout Cycle 5, 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 5 is given in Figure 4.8. Figure 4.9 shows the maximum values for the Heat Flux Hot Channel Factor measured during Cycle 5.

As can be seen from the figure, there was a 15*. margin to the limit at the beginning of the cycle, with the margin generally increasing throughout cycle operation.

The value of the enthalpy rise hot channel factor, F-delta H, which is a

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 eperation. The Cycle 5 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 5 is given in Figure 4.10.

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 equilibrium Pt-Pb

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

2775 Pb = power in bottom of core (?N(t))

17

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 -6% at the beginning of Cycle 5. After approximately one-third of the cycle, delta flux values had shifted to -4% and then moved to -3% by the end of Cycle 5. This power shift can also be observed in the corresponding core average axial power distribution for a representative series of maps given in Figures 4.12 through 4.14. In Map N1-5-15 (Figure 4.12), taken at approximately 250 E'D/MTU, the axial power distribution had a shape peaked toward the bottom of the core with a peaking factor of 1.25. In Map N1-5-23 (Figure 4.13), taken at approximately 7,000 E'D/MTU the axial power distribution had become slightly more symmetric with an axial peaking factor of 1.16. Finally, in Map N1-5-34 (Figure 4.14), taken at approximately 13,000 Mk'D/MTU, the axial peaking factor was 1.15. 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.

In conclusion, the North Anna 1, Cycle 5 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.

18

l TABLE 4.1 NORTH ANNA UNIT 1 - CYCLE 5

SUMMARY

OF INCORE FLUX MAPS FOR ROUTINE OPERATION l

l l 1  : H I 1 2 l i I l l BURN; F-Q (T) HOT F-DH(N) HOT CORE F(Z) l 4 1 i UP l BANK CHANNEL FACTOR '

CHNL. FACTOR MAX 31 C"TR AX1AL NO.

MAP l DATE MWD /. PWR D  !

F(XY)l OFF OF NO. l l MTU (%) STEPS '

l i l AXIAL. l l AX1AL  !

MAX SET THIM l lASSYLPIN l POINT F-Q( T ) : ASSYlPIN.F-DH(N) POINT F(Z) MAX LOC; (%) BLES l 1l

_- - I

'15 (5). 10-10-84 225 100 224 1 H071 10 ' 38 1.861 H07; IB 1.439 38 1.251 1.528 1.005. SE ' -6.15 48 l16 11-13 1441 1001 220 HO T . ID '

37 1 1.870 H07- In 1.464 38 1.233 1.5601 1.005l NE 49 l17 L12-14-84 2321 1001 220 H07 IB 37 1.872 H07; IB 1.482 38 1.217 1.555 1.008 NE ' -4.52. -4.78 42

18 1-14-85 3470 l100 220 110 7 IB 30 1.853 H07 '

10 1.489 38 1.196 1.563 1.005 NE ' -3.61 41 21 (6) 2-15-85 4701 :100 220 H07 10. 38 1.836 H07 l lBH 1.490 38 11.183fl.568 '1.008 NE -4.50 39 22 3-15-85 5614, 100 ' 220 C06 Pil 38 11.802 180 7 IBl 1.484 39 . 1.164 11.564 1.006 23 4-16-85, ' 6831 :100 224 ' F07 NE. -3.73 44 IPi 46 L 1.779 H07 IDH 1.482 46 1.15911.559 '1.003 NW -3.95 43 g 26 (7)I 5-17-85 8024 100 226 F07 LKi 47 l 1.777 , 110 71 IB 1.477 47 11.160 1.563 1.005 NE -4.27 44 e 127 19-85I 9287 ;100 221 F07 LKl 48 . 1.763 l F07 LK 1.467 47 L1.157L1.547 1.006 NE -4.35!

H29 (8) 7-18-85 :10399 100 ' 220 i L10' 45 Jll 48 i 1.755 F07? LK. 1.462 48 L1.153 1.540 1.009 NE -4.15 45 132 (9) 8-23-85 11139'100 223 L101 Jll 49 L 1.743 F071 LK 1.462 l 48 . 1.140 1.541 1.007 NE -3.29 45 l l' I_  !

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

FOLLOWED BY THE PIN LOCATION "Y" COORDINATE WITH THE SEVENTEEN ROWS Of FUEL RODS LETTERED A THROUGH R AND THE '(X" COORDINATEINDESIGNATEDDENOTED A SlHILAR MANNER). BY THE IN THE "Z" DIRECTION THE CORE IS DIVIDED INTO 61 AXlAL P0lNTS STARTING FROM THE TOP OF THE CORE.

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

( 2). F-DH(N) INCLUDES A MEASUREMENT UNCERTAINTY OF 1.04.

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

( 4). QPTR - QUADRANT POWER TILT RATIO.

( 5). MAPS 13 AND 14 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

( 6). MAPS 19 AND 20 WERE TAKEN FOR INCORE/EXCORE CALIBRATION.

( 7). MAPS 24 AND 25 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

( 8). MAP 28 WAS TAKEN FOR VERIFICATION OF MISALIGNED ROD.

( 9). MAPS 30 AND 31 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

l l llllII1Il

. MS OFlE 65 NOHL 44 l

TB IIl11l L 23 AFT) 72 1FE%

XOS( 33 A --

llI1ll C E O

R T lII11l L 7N _

P 07 Q X 10 A 00 M

11 llll1I1ll

) 06 YX 42 -

XA 55 -

(M _

1' F 11 .

,I

) 31 _

) -

Z 55 _

Z ( 11

( F . . _

FX 11 A

.1l EM LT R 33 O TAN I 55 C XO lI" AP

- LI

)

N 82

( 54 TR H 44 OO D

)

HT - 11 C F T

. )A N

NF

( .

N KMl.

LL .

O HL PI .

C DN lI

(

FC

- H lYS 76' 00 1 S 7C s

A i llll l '

)

E T 32 L ( 53 B Q 77 A R -

T TO F 11 OT HC LT A AN

)F 1I 33 I XO 55 (L AP E

QN  : ll

- N N LJ FA CI I_

I H P C 1li11l Y 60 S 01 S JL A l

-l

,Ilil S

K P 68 NDE 22 A T 22 B S ll' R) 60 W%

llIllIl1l P(

60 T1 _

N / 03 RPDU 98 UUWT 09 B MM 22 11 IlI11l 55 88 E - -

T 72 A 22 D - -

90 1

l i

P .

Ao MN 34 33 llll l l

E llll!

i l

Figure 4.1 NORTH ANNA UNIT 1 - CYCLE 5 ASSEMBLYWISE POWER DISTRIBUTION N1-5-15 0 P G II L E J N O r E D C 0 A

. M ASURf 0 . . n.30 . H.30 . 0.30 . M ASURtc . 1

.PC7 OlfftRtlICE. 4. S . 4. 5 . l.9 . .PC7 Olf fERCIICE.

.32 . U.66 I.00 . 0.96 . 1.00 . 0.66 . 0.33 . 2

. O3.3 . *0.7

. A.6 . 0. 6 . 0.4 . =0.9 . =t.S .

. 0. 3 7 . t .n3 . l. Il . l.23 . 1.23 . 0.74 1.83 . 1.09 . 0.38 . 3

. -3.3 . *3.3 . *t.t -n.6 . -0.7 . *0.4 . 0.8 . *0.7 . -2.2 .

. 0.37 . 0.64 . l.16 . l . .*6 4.23 . l.76 . l.22 . 1.28 . 1.17 . 0.84 . 0.37 4

. *3.4 . -2.7 . *P.S . *0.4 U.4 . n.3 . .n.t . 0.7 . =t.3 . 2.2 . *3.4 .

. 0.32 0.02 . l.16 . l.7% . I.77 8.79 . 1.22 . 0.72 . 1.74 9.77 . 1.16 . l.02 . 0.32 . S

.

• 3. 4 . - 3. 4 . = 2. 2 . = 1. 7 . *0 $ . 7.7 . 7. F . 2.0 . 1.5 . *0.4 . *t.3 . =3.9 . -3.2 .

. 0.66 . l.99 . 1.tS . 1.72 . 9.24 9.79 . l.00 . l.P9 . l.29 . 1.23 1.2S . 1.lt . 0.66 . 4

. al.2 . *l.2 . =t.1 . *t.0 0.9 . 3.3 . 3.2 . P.9 . l.7 . *0.4 . =l.2 . *l.2 . -0.4 .

. 0.3U . 0.99 . 9.24 l.22 . 0.19 . t.fi . l.16 . l.30 . 3.16 . l.30 9.23 . l.22 . 9.2S . l.01 . 0.30 7

. 1.0 . *0.3 . *0.3 . -0.6 . *1.1 . 0.0 3.3 . 3.2 . 3.2 . 2.9 . 2.2 . -0.0 . l.8 . 1.3 . 2.2 .

. 0.47 . 0.9% . l.23 . 4.27 . 1.22 . t.no 9.30 . 1.32 . l.29 . 1.04 . 9.20 8.26 . 9.25 . 0.99 . 0.90 . 8

. al.8 . =0.4 . *0.5 . 0.6 . F.6 . F.6 . 2. 7 . P.S . f.0 . 2.0 . 1 3 . =0.8 . l.0 . 4.9 . 4.7 .

. 0.29 . 0.97 . l.29 . 1.72 . l.73 9.74 1.12 I.27 l.84 1.20 . 1.22 . 1.23 . 9.2S . 8.02 . 9.39 9

. *2.S . *2.9 . *f.9 . *0.3 . P.6 1.4 0.2 . l.0 . 1.6 . 1.S . l.S . 0.4 0.6 . 2.4 . 4.2 .

. 0.6S . 1.10 . 9.27 . l.74

. *2.S . *2.9 . -0.2 .

t.?S . l . t% . l.05 . I.25 . 1.27 . 1.23 .

1.0 . 0.7 . *0.4 . 0. 3 . +0. 2 . =0.1 . -0. 8 . 0.8 . 0.7 . 4.9 1.76 . l.14 . 0.69 . 10

. 0.32 . l.03 . l.16 . 0.7F 1.73 8.99 1.18 . l.09 . 1.22 . 1.27 l.19 . 4.04 . 0.33 . It

. -3.9 . -3.1 . -2.2 . *0.S . *0.4 *0.6 . *0.6 . =0.0 . -0.7 -0.3 . -0.4 . -0.4 -0.9 .

. 0.37 . 0.44 8.08 . l.76 . l.28

• 24 . 1.70 . 1.25 . 1.97 . 0.09 . 0.34 .

13

. -3.7 . *2.2 . .n.S . *0.# . =0.8 .

• l . 2 . a l . 6 . = l . 4 .

• t . 4 . = t .1 . = t . 4 .

. 0.34 . I.f4 . l.It . 1.73 . 1. 1. l.23 . 1.12 . 1.04 . 0.34 . 13

. 3.0 . *7.3 . al.6 - 0 . 2 . *0. 4 . *0. 9 . -te . s . = 2.1 . - 1. 4 .

. 0.33 0.a9 1.04 . 0.99 . 0.99 . 0.66 . 0.32 14

. *F. 3 . 3.6 4. 3 . 3. 5 . -u. e . 0. 6 . =2. 7

• ' * * *6:ir:'63r:*6:i6':* """""" iS

. 9.9 . S.e . i.S .

siamoan0 Ocvlafica . t.See avtnact PCF. OsttratsCc = t.7

SUMMARY

MAP NO: N1-5-15 DATE: 10/10/84 POWER: 100%

CONTROL ROD POSITIONS: F-Q(T) = 1.861 QPTR:

D BANK AT 224 STEPS F-DH(N) = 1.439 NW 0.996 NE 1.004 F(Z) = 1.251 SW 0.995 .i SE 1.005 F(XY) = 1.528 BURNUP = 225 MWD /MTU A.O = -6.15(U 21 1

Figure 4.2 NORTH ANNA UNIT 1 - CYCLE 5 ASSEMBLYWISE POWER DISTRIBUTION N1-5-23 e , w n t a J w e e e o e e a sota9Utf9 . . 0.30 , 9.48 . 9.19 . 8'f ailefD . 1

.. PCT O!rrteftf. 9.1 0.1 0.9 .FCT O!Ff tffWt.

0.31 . 0.64 . 0.9% . 9.99 . 9.94 . 0.64 . 8.33 . t

.t.9 , t.t . .l.3 , .t.4 . 1.6 .t.9 . .t.9

. 9.18 . 9.99 . 1.11 ,8.15 . 1.tt . 1.19 , 1.12 . 1.89 . 4.39 1

. .t.9 . .t.S . 1.t . 1.3 . *t.3 . 9.7 0.1 . 0.7 . .t.7 8.14 . 9.94 . 1.10 . 1. 21 . 1. 2 0 . 1. 2 2 . 1. t e . 1. 2 3 . 1.10 . 0. 4 7 . 9.18 4

. 1.3 . .l.9 0.0 . 9.5 . 0.4 . 44 . .t.t . 1.6 . 9.9 . .t.8 . .t.4 .

. 6.11 . 9.97 1.17 . 1. f t . 1. 3P . 1. t 6 . 1.12 . 1. t l . 1.1t . 1. 2 3 . 1.10 . 6. *9 . c .13 . 9

4. 0 . 4. 9 . . t . ? . 0.7 1.4 . f.) . f.1 . 2.2 , 1.7 , 9.8 . 9.4 . .t.7 3.7

. 0.64 . 1.19 . 1.ft . 1.11 . 1.20 . 1.37 l . I t . 1. 3 7 . 1. t e . 1. 31 . 1. 21 . 1.19 . 9. 6 3 . 6

.t.7 .l.7 . .t.9 9. ? . 3.1 . 1.4 . 3.5 . 3.3 . 2.2 . 0.9 . 9.0 -t.1 3.4 .

. 9.19 . 9.*9 . 1.19 . 1.27 . 1.91 . 1.19 . 1.le . l.37 1.17 1.37 3.16 . 1. t ? . 1.14 . 9. *4 .e.ft.  ?

9.6 . .l.5 , 9.9 . 0.7 . 9.1 . 1.0 . e.9 , 3.9 3.5 3.1 . t.1 . .t.4 , .l.6 . .t.1 . -t.4 .

. 0.47 . 9.69 1,71 , 1.21 . 1.79 . 3.19 . l . 3 7 . 1. t * . 3.16 . 1.11 . 1.31 . 1.!! . 1.81 . 0.99 . 9.48 . 4

.t.7 . l .1 . l . t . 0. 7 6.1 1.7 1.9 . 3.4 . f.6 , t.6 . 1.9 . 9. 0 . .l.4 . 9.9 9. 3 .

. 9.P9 . 0.94 . 1.13 . l.26 . 1.23 . 3.11 . 1.14 . 1.14 . 1.16 . 1.36 , 1.79 . 1.tt . 1.11 . 0.94 . c.19 . 9

.t . t . .t.4 .t.4 . . t . 6 . 0 .1 , 9.8 . 9.4 , 1.0 . t .1 . t.t 1.9 . 0.1 0.9 =0.9 . 9. 2 .

. 0.64 , 1.30 . 1.20 . 1.12 . 1.t6 . 1.13 . 1.99

. 1.14 . 1.76 1.11 . l.23 . 1.12 . 0.69 . 19

.t.9 , . t . O , t .1 . 1.6 1.0 0.1 . 1.2 . 0.9 . l.9 . 0.8 . t.1 9.1 0. 3 . .,

9.13 . 9.** 3.18 . 1.24 . 1.38 . 1.t1 . 1.29 . 1. t 3 . 1.19 . 1. t 5 . 3.19 , 1.09 . 9.11 . 11

.t.9 . =1.9 0.7 1. 4 . 0. 7 . 9.2 . 4.2 , 9.2 0. 3 . 1.2 . 0.9 . 9. 9 . .l.0 .

. 9.la . e.87 3. 3 0 . 1. t t . 1. 28 . 1. t2 . 1. 7 7 . 1. t9 . 1.18 . 0. 8 7 . 9.19 It

.t . 8 . 9. 2 . 1.4 , 0.8 . 9.9 . 9. 9 . 0.9 . 9.8 . 0.0 . .l.8 . 1.2 .

. 9.19 9.98 . 3.11 . 1.16 . 1. t 1 . 1.13 . 1. 0 9 . 9. 99 . 9.39 11

.t. t . .t . 6 . . l . 3 . 0.0 . .l.7 . .t.F . .t.6 .t.9 .l.2 ,

. 8.11 . 0.66 . 1.09 . 0.91 . 0.93 . 0.63 . 9.33 . to

.t.6 . 9.9 4.7 8.1 . .t.e 2.7 . .t.9 .

. 9.11 . 9.48 . 0.29 Il 4.7 i 9.7 3.5 .

vsWa o ervta7wu = 1.099 avreast pet. OterretWe

• 1.s

SUMMARY

MAP NO: N1-5-23 DATE: 16/16/85 POWER: 100%

CONTROL ROD POSITIONS: F-Q(T) = 1.779 QPTR: t O BANK AT 2214 STEPS F-DH(N) = 1.882 4 NW 1.003 l NE 1.003

...........i..........

F(Z) = 1.159 SW 0.996 l SE 0.998 F(XY) = 1.559 BURNUP = 6831 MWD /MTU A.0 = -3.95(%)

22

l l

l Figure 4.3 NORTH ANNA UNIT 1 - CYCLE 5 ASSEMBLYWISE POWER DISTRIBUTION N1-5-34 a P e M L E J M 0 F C 0 C e A

' 'N EiuN b ' .* *bl35blSi'.'b$55'l 'N EiUN b

.PCF GeFFEAtact. 4.4 , 4.4 2.5

. . 3

......... ..... .PCF DIFFERthCE.

. 0.36 . 0.67 . 0.96 . 0.90 . 0.96 , 0.67 0.36 .

0.4 1. 0 . 1. 0 . 1.0 0.9 . 0.5 2 1.0 .

. 0.42 . 1.00 1.15 . 1.92 1.22 . l.13 . 1.1% 0.01 0.42 .

. 0.4 . 0.4 , 1.0 . -0.S -0. 7 , *0.1 1.2 . 1.3 . 1.5 3

. 0.49 . 0.64 . 1.20 1.18 .................................................

l.30 , 1.99 . 1.30 . 1.20 . 1.21 . 0.09 3.41 .

. - 1. 2 . =0. 7 . 0. 3 . 0.2 . *0.5 . -0.6 . -0.2 4 1.7 0.9 . 0.5 0.0 .

. 0.35 . 0.97 . 1.18 . 1.18 1.38 . l.22 1.33 . 1.22 1.34 1.19 . 1.19 . 0.99 0.36 ,

. -2.7 . =2.7 . 1.5 . =0.4 -0.7 . 0.5 . 0.6 . 1.1 . l.2 . 0.6 . -0.1 S

............................................................... .............. -0.7 . -0.0

. 0.66 . 3.12 . 1.97 1.38 1.22 . 1. 3 % . 1.10 . 1.35 . 1.23 . l.32

. 1.14 1.13 . 0.66 .

. *0.4 . -0.4 . =0.0 *0. 9 . 0.1 1.4 6 l.6 9.9 . 1.3 0.0 -0. 2 . *0.7 . -0.4

. 0.32 . 0.94 1.12 1.28 , 0.18 1,32 . 3.14 1.35 . 1.93 . 1.35 1.22 1.29 . 1.12 . 0.94 0.32 .

. I.2 . -0.6 . =0.S . -l.S . -2.4 -0.7 . 2.7 2.6 . 2. 0 , 1.7 0.7 . -1.3 -0. 7 . -0. 7 0.0 7

. 0.49 . 0.89 . 1.22 1.14 . 1.20 . 1.00 l.3% .............. 1.23 . 1.33 . ............. .................... .......

l.09 1.32 , 1.18 . 1.22 . 0.90 , 0.52 .

. *2. 6 . -0. 7 . -0. 8 . = 0 . S . *3.0 . -0.3 2.6 . 2.4 1.2 . 1.1 8

-0.1 -1.4 -0.7 . 1.2 2.6

. 0.31 . 0.93 . l.10 . 1.27 1.14 1.30 1.10 1.32 1.12 1.34 1.22

. -2.6 . -2.6 -2.6 . -2.8 . -3.0 . 0.9 0.6 . 0. 7 . 0.S 1.30 1.83 . 0.97 . 0.33 9

-0.8 . 0.3 -0.S 0.0 , 3.2

. 0.6% . 1.00 . 1.20 . l.34 .................... 1.22 . 1.30 . 1.07 ...... 1.31 .

1.21 1.32 . 1.19 1.14 . 0.69 l.4

. -2.6 . 2.6 . 1.7 0.7 0.4 -2.0 , *0.4 10

-1.0 . -0.3 . -0.4 . l.3 . 0.8 . 3.S .

. 0.37 . 1.01 1.21 . l.21 .................................. ....................

1.32 . 1.19 . l.29 . 1.19 . l.32 1.20 , 1.21 . l.00 . 0.36 1.5 11

. l.4 . 1.4 . 1.7 . -0.3 -2.0 . 2.1 -0.9 , -0.3 0.7 1.2 0. 0.7 .

........................................................................9, ...

. 0. 42 . 0.90 . 1.28 - 1.14 , 1.27 1.l7 1.28 1.10 1.20 1.4 1.9 . l.7. 0.1 2. 2 . 2.2 1.4 . 0.3 0.89 0.42 . 12

0. 2 . l.1 1.1

.............. . 0.42 . ...... .............

1.83 0.11 ............. ...... .............. . .

1.09 1.21 1.12 . 3.13 1.00 , 0.42 13 1.3 . 1.3 . -0.2 . -1.6 . al.4 . -0.9 . -0.6 0. 3 . 1.1 .

. 0.37 . 0.70 0.99 0.92 . 0.94 . 0.66 0.36 14

. l.3 . S.6 . 4.5 2.4 -0.9 , -0.4 . -0.4

. 0.3% 0.S3 0.39 15

. 10.1 4.4 . -0.8 .

STCAMio OtviA710se a 1.234 Avt AACC PCF. Ot FFERt4CE = 1.3

SUMMARY

MAP MO: N1-5-34 DATE: 10/22/85 POWER: 100%

CONTROL ROD POSITIONS: F.Q(T) = 1.732 QPTR:

D BANK AT 228 STEPS F-OH(N) = 1.442 NW 0.996 l NE 1.007 F(Z) = 1.151 SW 0.997 I SE 1.000 F(XY) = 1.526 BURNUP = 12983 MWD /MTU A.O = -3.23(%)

23

Figure 4.4 HOT CHANNEL FACTOR NORMALIZED OPERATING ENVELOPE s .2, (6.0, 1.0) 1.0 (10.91, 0.94)-

-~

K ,

a 0.6 i Z

\

N M 0.6 A

L i

Z E 1 0 1 F 0.4 ' (12.0, 0.45) e <

a I .

0.2 '

0.0 ,.

0 2 4 6 6 10 12 CORE MEIGHT IFil BOTTOM TOP 24

Figure 4.5 NORTH ANNA UNIT 1 - CYCLE 5 HEAT FLUX HOT CHANNEL FACTOR, F (Z) ,

N1-5-15 2.S

• m

• A

• N .

m pq f.0

• g '

" ~

. maaaa a g . R EME N N R R R RM g . R R RR p . N N R RaR Q - MN RR.

o, t.S

• a aan a.

3 w .

R

. N

= . .

u .

F* . R RR e ... .

= . m

. A sa  :

~ .. . ,

e  : .

g 0.9 +

am 30ff0M OF C08E

- la - ,- .,-  ;,- 1.-  ;,-  ?,-  ;,- - l. -  ;- -l TOP Of COAE AXIAL POSITION (NODES) 25

Figure 4.6 J

NORTH ANNA UNIT 1 - CYCLE 5 HEAT FLUX HOT CHANNEL FACTOR, F (Z)

N1-5-23 e.. .

w w

=

f* O -

4

• u W

• IEE EEE ENENNNE e  : ,==,, ,

- NN5NN. .....

o . .

g i.. .

= = -

m

. , N

.4 w .- .

y .E 8 s ... .

o .

N l2".

x . .

= .

d  : .

y . .

d

2:

,.....;,....;,.....,....g.....,....g....

, i.

i. . ,

708 SF CSD, AXIAL POSITION (NODES) 26

Figure 4.7 NORTH ANNA UNIT 1 - CYCLE 5 HEAT FLUX HOT CHANNEL FACTOR, F (Z)

N1-5-34 m *

^

• N

• w t.. .

Of

• 4 0

• xe a asus

• N NR NN g

4 NNERMN 2RNN NMREp g3 gg 4 =

... .. =, = == ,- = .

a  :. .

= = - -

m x

a .

s o ...:. .

= .

x o

.a Ed  :

s  :

s ..,.

=  :

,.. . . ;,. . . . g. . . . ;,. . . . ;,. . . . ;,. . . ;,. . . . ;,. . . . , =. . . . , . . . , , , , , , ,, , , , ,

,,,,,,,o,, , .. ,

W .F M AXIAL POSITION (NODES) 27

Figure 4.8 NORTH RNNR UNIT I - CYCLE 5 MRXIMUM HERT FLUX HOT CHANNEL FRCTOR. FO e P VS RXIRL POSITION FQ s P LIMIT a MAXIMUM FQ = P 2.4-22

'N A

^

2.0

~

. l ll g,g :na . + .

.*, e' *

• • • o

,,, , ,. ,0e g 4 ,n l.6 .

-a s

1. 4 ,

~

+

in

1. 2 ,

1.0 *

• h 0.8 0.G -

0.4 -

~

0.2 0.0-i 61 55 50 45 40 35 30 25 20 15 10 5 1 RXIRL POSITION INODEI BOTTOM OF CORE TOP OF CORE 28

Figure 4.9 NORTH RNNR UNIT 1 - CYCLE 5 MAXIMUM HEAT FLUX HOT CHANNEL FRCTOR, F-0 VS BURNUP

- TECH SPEC LIMIT X MERSUREO VRLUE 23 .

2.2 -

M '

R X .

I 2 .1 M

U .

M .

2.0 -

H E  :

R .

T 1.9

- x x x ,

7 L .

U 1.8 Y X x :c x y ,

H  : ):

0 1.7 T

C  :

H 1.6 R

N  :

N .

E 1.5 L  :

F  :

R 1. 4 C -

T 0 .

R 1.3 1 . 2 -s -

0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MND/MTU) 29

f Figuro 4.10 NORTH RNNA UNIT I - CYCLE 5 ENTHALPY RISE HOT CHANNEL FACTOR F-OHIN) VS BURNUP i

TECH SPEC LIMIT X MERSURED VALUE 1.60 1.55 E 1 50 N x x T x x x ,

• x R x g L 1 45 ~

P x 3:

Y -

R I 1.40 S

E H

0 1.35 '

i C

H A 1.30 ' '

N .

I t ) - J..

1.25' '

F -

R

, C -

l T l

0 1.20 R

~

1.15' l

1 102 'l 0 2000 4000 6000 8000 10000 12000 14000 CYCLE SURNUP (MND/MTU) 30

Figure 4.11 NORTH RNNR UNIT I - CYCLE 5 TRRDET DELTR FLUX V6 BURNUP 10, 4'

2:

D'

-g' A A a a j

-4:  :  :

A & <k A

-s-;,:

-s:

-102 ,. .

0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MWD /MTU) 31

Figure 4.12 NORTH ANNA UNIT 1 - CYCLE 5 CORE AVERAGE AX1AL POWER DISTRIBUTION N1-5-15 Fg = 1.251

A. O. = -6.15 MMM MM M MM MM 1.2

• MM M M

= M MMM M M M

= M M MMM M

- M MM M M

. MMM

. M

. M M M

. MM W

.., .. M M M M

. M

- M

. M

. M g -

M w M

- M

- . M 0~0.6 +

M M

- M

. M

• M

-M 0.3 + M

. M

.};;; j, W or mg AXIAL POSITION (NODES) l 32

Figure 4.13 NORTH ANNA UNIT 1 - CYCLE 5 j CORE AVERAGE AXIAL POWER DISTRIBUTION N1-5-23 i.s .

. F = 1.159

. 2

. A. O. = -3.95 i.a e NMM MM MM NNNNX XX R

R M MM NMN gxxx,, , ,,,

- - - - = ,,

a

• x a C.9

• x "

e

~

K

.I  : -

. =

... ;

~ ., =

.-=

. =

C.3 * *

,.....;,....g. ..;,....g....;,....;,. ..;,. ..;,. ..,.. , .;,... ;.  ;

00ff0M Of CORE TOP 0F CORE AXIAL POSITION (NODES) l I

l

[

\

l l

l 33 i

Fi9 Ure 4,14 NORTH ANNA UNIT 1 - CYCLE 5 CORE AVERAGE AXIAL POWER DISTRIBUTION N 1 34 i.s .

. Fg = 1.151 A. O. = -3.23 i.2 *

• NNA RRR

= 5 RRM

= M N N RA 3xx

• A NNNN NANNN NNNXRN N NN

• N A A A N M

• M

• N NN N

. , M ,

g 0.9

• ax

~ .

. k M

a w

x e~ e.. .. N =

M

,. . . . . ;,. . . . g. . . ;,. . . g. . . ;,. . ;,. . . ;,. . . ;,. .

soff p OF Cent i

TOP OF CORE AX1AL POSITION (NODES) l l

l 34 l

Figuro 4.15 NORTH RNNR UNIT I - CYCLE 5 CORE RVERAGE RXJRL PERKING FACTOR. F-Z VS BURNUP 1.4 i

13 R -

X 1 .

R L

a P

E A R

K 1.2 1

A N , a G

F . A p A i k g

g a 6  ;

T a O

R .

t l

1.1 l

' j I

I l

1

~

l l 1.0-0 2000 4000 6000 8000 10000 12000 14000 CYCLE BURNUP (MWO/MTU) 35

Section 5 l

PRIMARY COOLANT ACTIVITY FOLLOW i

i l

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 through 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 5 core. The demineralizer flow rate averaged 88 gpm during power operation. The data shows that during Cycle 5, 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 -2

3. 8 x 10 pCi/gm is equal to 3.8*. of the Technical Specifications limit.

The step increase of coolant activity in July 1985 is due to recalibration of the germanium-lithium detector that is used to count the .

coolant samples. The change in coolant activity measurements was not caused by a fuel cladding defect formation event. However, it appears that a fuel rod failed in September, as indicated by the presence of iodine spikes.

During the visual post-irradiation fuel examinations, it was apparent 36

that some impingement of coolant, through the baffle joints onto a peripheral fuel assembly, had occurred. The resultant vibration of several fuel rods weakened the grid springs but there was no conclusive evidence of fuel cladding through-wall defects due to baf fle jetting.

The ratio of the ' specific activities of I-131 tc 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 decays out leaving the I-131 dominant in activity, thereby causing the ratio to be 0.5 or more. In the case of large leaks, uranium particles in i the coolant, and " tramp" uranium *, where the diffusion mechanism is negligible, the I-131/I-133 ratio will generally be less than 0.1. Figure 5.2 shows the I-131/I-133 ratio data for the North Anna 1, Cycle 5 core.

These data generally indicate there were probably a few relatively large defects in the fuel used during Cycle 5.

1 a

l

(

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

37

Figuro 5.1 NORTH RNNA UNIT 1 -

CYCLE 5 DOSE EQUIVALENT I-131 vS. TIME TECHNICRL SPECIFICRTIONS LIMIT O

~

O O

~ e .

2 g go

,e. W e V -

i 0- . s e:= . , es f:

e o e  :-go e u e O s Oe o

$"D u -

g 0

e

. 9 O O u- '

~O g O E- M

~

e

~

f O

~

~

[

N I M P D

~

l 5

^* 5

. M -

g t e-i _ g l I I l l 8 l l l l l l OCT NOV OEC JRN FEB MRR APR MRY JUN JUL AUG SEP OCT NOV 1984 1985 38

- - - - - - - - - o-.- - - , , , - en >w - -

Figura 5.2 NORTH ANNA UNIT 1 -

CYCLE 5 I-131/I-133 ACTIVITY R AT I O vs. TIME a

l E E

e o-

~C x

e

>d

~

0 o

U O C

O mN mg 'o T e I

ny e o 0 O 4 i O O e .,

.D C

O W q

o y ,

- ,- - - I U, y

50 g e -

g I

l I I g' A

I I l l l l l OCT NOV DEC JAN FEB NRR RPR NRY JUN JUL RUG SEP OCT NOV 1984 1985 39

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

Section 6 CONCLUSIONS l

l I

The North Anna 1, Cycle 5 core has completed operation. Throughout this cycle, all core performance indicators compared favorably with the design

_ predictions and the core related Technical Specifications li,mits were met with significant margin. No significant abnormalities in reactivity, power distribution, or burnup accumulation were detected. In addition, the mechanical integrity of the fuel has not changed significantly throughout Cycle 5 as indicated by the radiciodine analysis, although one fuel rod failure apparently occurred late in the cycle, i

2 J

i 40

Section 7 REFERENCES

1) C. A. Ford, " North Anna Unit 1, Cycle 5 Startup Physics Test Report," VEP-NOS-10, October, 1984.

2) North Anna Power Station Unit 1 Technical Specifications, Sections 3/4.1 and 3/4.2.

3). T. K. Ross, "NEWTOTE Code", VEPCO 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.

s t

41

,. _ . . _ - , . - - _ , _ . _ , _ . - _ . .__ . _ . . . . - - _ . . _ . - . . . - _ _ _ - - _ . _ _ _ _ _ - - _ . _ . - _ . - _ _ _ - . . , . . _ _ _ _