Text

Cycle 4 Core Performance Rept
	ML20155F572
Person / Time
Site:	North Anna
Issue date:	03/31/1986
From:	Iannucci J, Mann B, Snow C; VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	;
Shared Package
ML20155F564	List: ML20155F561; ML20155F572;
References
	VP-NOS-24, NUDOCS 8604220265
	Download: ML20155F572 (49)
	v • d • e

'

+

' * ^ g ., ,* .,. _

p

"' . + '

. 6 ** +. ,

"A-. /

+ = * ' # +'

(f . v. \ g ,.

, (

k; k,. w$%t,%,.w...A,

%e%v ,,

' ~pw t

[

5 n

s.

,y e- 2+l '

2

.q L u ; &. .

p

...,,.j W,- .. . ,

.$s.%/$.a . - :-

., , m

- . .C

{':NM y, y ; - y ,h , :

..(. (y,.. .g n ' I. -

w.

. ( ,

- es 1 -

g

=.

,.. 'p g., .

._ ,Q? '

x* c e .--

i ^s. % . .' ;-

v id h /.

,7 g

., Y # '

F

(

= .

9 K _ ,_ '- ..

- f . s,* 4 . . .

g &

.- ;y .

y U ,

., Y D

. > . N 9

is . .

1 .* ' g g -

. t- .

g %

._' S -

h y 'M l

^

g9 ..

= f '.

kr

s J *.

.g 4' ,

4 l t

+

+ e _ _

- E e

=

w g , ,

Y

/

0 -

p '$

}: .*

, 9

$m .

S

=

O _.',-

, .f -

3

p.

,. - - - - - - - _ e

c. . .-

g O :

f' .. .

( , . : 8 ,

k -

a' .

/;.'.

T

2 ?.

I, 24 l g J. .

v ;r.

^ '

.e ; '..

. e .

t s-

a

, , g

. .N . .

.4 .

. W '

O r

t w . g q * ' . -

)

s .

a. +

.. m. - --.-- ., .

.g . _ .- -' .' .

. . 4 e

+S' ,

f ._ . . .. ,

*

i.. * '

g* .,h,*' ,d . , . * ! ) _.' ,,,...,,%,..* * *. . . . *.

9. , . , 5.- [ .,;',.,.,'

,e E

(.n' v . *. .P.. ...._.'........

y. -> . ..a. .. , . ; , . .: - . . . . t._.,,,i,-*- , ;

I VP-NOS-24 I NORTH ANNA UNIT 2, CYCLE 4 CORE PERFORMANCE REPORT I by J. V. Iannucci I

I I

Reviewed: Approved:

I M0 %

BT D. Mann, Engineer C.1 La C. T. Snow, Supervisor Nuclear Fuel Operation Nuclear Fuel Operation I Operations and Maintenance Support Subsection l

I Nuclear Operations Department Virginia Electric & Power Company Richmond, Virginia j

l March, 1986 l

)

1 I '

l I - - _ - - - - - - _-

I CLASSIFICATION / DISCLAIMER I

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 I

property, or other damage resulting from or arising out of the use, authorized or unauthorized, of this report or the data, techniques, I information, or conclusions in it.

I I

I

I I

TABLE OF CONTENTS I

I SECTION TITLE PAGE NO.

Classification / Disclaimer . . . . . . . . .. . .i List of Tables . . . . . . . . . . . . . .. . . iii List of Figures . . .. . . . . . . . . .. . . iv 1 Introduction and Summary. . . . . . . . . .. . . 1 2 Burnup Follow . .7 I' . . . . . . . . . . . . . . . .

3 Reactivity Depletion Follow . . . . . . . .. . . 14 4 Power Distribution Follow . .. . . . . . . . . . 16 5 Primary Coolant Activity Follow . . . . . . . . . 37 6 Conclusions . . . . . . . . . . . . . . . .. . . 41 i 7 References. ..................42 I

I I

I 11

I I

l LIST OF TABLES I

I TABLE TITLE PAGE NO.

I f

I " " - " ' " - " ~ ' ' " " - "" - - - - - - - - '

Iw e h

I I

I l

l ,

I l

'I I

iI I

I 111

I I

LIST OF FIGURES

(

I FIGURE TITLE PAGE NO.

I 1.1 Core Loading Map . . . . . . . . . . ......... . .4 1.2 Movable Detector and Thermocouple Locations. . . . . . . . . .5 1.3 Control Rod Locations. ......... . . . . . . . . . 6 I, 2.1 Core Burnup History . ......... . . . . . . . . . .9 2.2 Monthly Average Load Factors . . . . . ........... 10 2.3 Assemblywise Accumulated Burnup: Measured and Predicted . . . 11 2.4 Assemblyvise Accumulated Burnup: Comparison of Measured and Predicted . . . . . . . . . . . . . . . . . . . 12 2.5 Sub-Batch Burnup Sharing .

I 3.1 Critical Boron Concentration versus Burnup - HFP-ARO . . . .

13

. 15 4.1 Assemblywise Power Distribution - N2-4-07 . . . . . . . . . . 22 4.2 Assemblyvise Power Distribution - N2-4-23 . . . . . . . . . . 23 l 4.3 Assemblywise Power Distribution - N2-4-38 . . . . . . . . . . 24 4.4 Hot Channel Factor Normalized Operating Envelope . . . . . . . 25 4.5 Heat Flux Hot Channel Factor, F (Z) - N2-4-07 . . . . . . . 26 4.6 Heat Flux Hot Channel Factor, F (Z) - N2-4-23 . . . . . . . . 27 4.7 Heat Flux Hot Channel Factor, F (Z) - N2-4-38 . . . . . . . . 28 4.8 Maximum Heat Flux Hot Channel Factor, Fq*P, vs.

Axial Position . . . . . . . . . . . . . . . . . . . . . . . 29 4.9 Maximum Heat Flux Hot Channel Factor, Fq , versus Burnup . . . 30 4.10 Enthalpy Rise Hot Channel Factor, F-DH(N), versus Burnup . . . 31 4.11 Target Delta Flux versus Burnup . . . . . . . . . . . . . . 32 I

I I i'

I I

I LIST OF FIGURES CONT'D FIGURE TITLE PAGE NO.

I , 4.12 Core Average Axial Power Distribution - N2-4-07 . . . . . . . 33 4.13 Core Average Axial Power Distribution - N2-4-23 . . . . . . . 34 4.14 Core Average Axial Power Distribution - N2-4-38 . . . . . . . 35 4.15 Core Average Axial Peaking Factor, Fg , versus Burnup . . . . . 36 5.1 Dose Equivalent I-131 versus Time I

. . . . . . . . . . . . . . 39 5.2 I-131/I-133 Activity Ratio versus Time . . . . . . . . . . . 40 I

I I

I lI lI

.I I

'I 1

V

I I

I Section 1 I INTRODUCTION AND

SUMMARY

I On February 20, 1986, North Anna Unit 2 completed Cycle 4. Since the initial criticality of Cycle 4 on November 2, 1984, the reactor core produced approximately 95 x 10' MBTU (15,934 Megawatt days per metric ton of contained uranium) which has resulted in the generation of approximately 9.2 x 10' KWHR gross (8.7 x 10' KWHR net) if 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 2, Cycle 4 Startup Physics Test Report and, therefore, will not 1

be included here.

North Anna Unit 2 was in coastdown from January 23, 1986, at which time I the burnup was approximately 14,938 MWD /MTU. The coastdown, therefore, accounted for an additional core burn of 996 MWD /MTU from the end of full power reactivity.

I The fourth cycle core consisted of four batches of fuel. The North Anna 2, 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.

I acuti e cor- < 11ow 1 vo1 es ts- a 1xsi- o< tour er1 cigai I '

I I

performance indicators. These are burnup distribution, I

reactivity depletion, power distribution. and primary coolant activity. The core burnup distribution is followed to verify both burnup 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.

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 2 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 2 Technical Specifications, and to assess the integrity of the fuel.

Each of the four performance indicators is discussed in detail for the North Anna 2, 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 0.29% with the burnup accumulation in each batch deviating from design prediction by less than 1.8%.

2. Reactivity Depletion Follow -

The critical boron concentration, used to monitor reactivity depletion, was consistently within 0.22*. AK/K of the 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 month indicated that the assemblywise radial power distributions deviated from 2

I I

the design predictions by an average difference of less than 2*.. All hot channel f actors met their respective Technical Specifications limits.

4. Primary Coolant Activity Follow - The average dose I equivalent iodine-131 activity level in the primary coolant during Cycle 4 was approximately 2.0 x 10 -2 I Ci/gm. This corresponds to 2*. 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 densifiestion effects were observed.

I I

I l NOB 1H YNNY nNll Z - 3A373 P snastt s

30B3 7OYGINO WVd W d N N 1 W P N O A 3 0 3 e V utr tic uce 529 121 L.II_ 406 M ttE tt9 ta ta a L11_ L12_ 156 . W05 196 L11 101 190 546 ed 194 2Od L9d ed t llE,_ 19,L._ 159 954 L.32_ 51,,,. 156 L32_ lit 999 fbl 894 304 SS 404 L94 4 SSE L11_ LLI,_ utl 120 L11_ 551 1?4 125 urt 1tO 105 111 te 194 204 ed 4d 204 494 4d 1

- seO L13_ s04 L22_

god 841 L12_ vt6 Lil_ L12 LE1_ L19_ Li2_ s05 L94 694 L94 god 694 9 W44 L19._ E L21,_ Li2_ 106 ulf lit set L1I_ s09 L31 WFI L11_ W99 4d 204 ed L9d 69d 694 ed 204 ed L 506 L11_ A 995 _tgI_ v90 L11_ tig_ L11_ L19, L11,_ L11_ L31_ VT9 ,,311_

04 94 :94 ss a04 s vt9 L21_ L11_ L11_ *t4 LIi_ L11_ Lqt._ usO L11_ L12_ Lg g,_ urg L1L_ Lu._

ta sod ed :94 :94 L94 ed a04 ed e

,131_' Li2_ S*6 1ES L11_ L.I.f_ L12_ 110 W09 Lit _ 912 155 909 69d 404 L94 L9d 204 494 LO LE1_ 15E 199 L{i_ L11_ 32[._ tif S=t L21 utO Li2_ 109 tif ed L9d 204 ed ed go d L9d ed 11 942 S44 LI.f_ stl L11_ 1*0 190 L1i_ L11_ 321 _ 1t6 94 a04 ss a04 :94 ac L11_ 111 19f vF6 A L12_ L.JI_ 109 150 ed :94 a04 :94 te e is stO lit LiL_ L2L_ _ni_ til_ se5 ed ed LD u0t ser wor

- < V$$3W91A 00 l LE

--< om1 OJ 1W3 J0110RtNO l V- ss - s3somovvA sonm33 G* Wd - tnehv913 dOISoh V$$3N97A l a-anusiv os uoos(

dn31 VSS3W91"A 03SION dYUVW313WS S38 EY1CI W CYC YYZ 5V 9Y INllIfT 3NHIDIH3NI

)A/O a-ZCS( C*fO C'tI C'56 C'90 m YESIKE11.f.id3 ILXIL IIXIL IIXIL ILXIL NaWt3H OJ YSS3WE1I3S I C9 59 91 1

3331 H0GS d3H TSS3WE11 Z91 Z91 Z91 Z91 TSS3Ht11 IG3NIIdf::71 ION dC6 NOI HOC S01 S59 101-199 805 804 51L Xt6-HZI Xt9 Ht9 HZ9 HCO HCZ'HCC H09 HCS H10'E9E H*t'899 59L H5Z'MfO I '

I I Figure 1.2 NORTH ANNA UNIT 2 - CYCLE 4 MOVABLE DETECTOR AND I THERMOCOUPLE LOCATIONS I

I R P N M L K J H C F E O C 8 A MO TC 1

TC TC MD 2 I I MD I TC i '

TC I i

i MO MO TC TC NO TC 3 TC MO MD I

MO TC as M0 M0 MD MO TC I MO TC TC MD TC TC 5 MO TC TC MO TC MD II TC TC M0 MD MD TC MO MO 6

T l MO MO I MO TC ! TC i

MO TC TC TC TC i MO TC i TC Mo TC 8 l i l 1 MO i TC MD i TC Mo i TC MD l '

9 l MO I

M0 MD I TC l l TC TC i

g MD I TC 10 1 MO MO I TC l Mo TC TC i TC MI5 11 I t TC MO TC MD TC M0 TC I

( TC MO 0

TC 12 13 I MO - Movable Detector TC - Thermoccuple MO TC MO TC I ts MO TC TC ,

I 15 I

I I 5 I

I I

I Figure 1.3 NORTH ANNA UNIT 2 - CYCLE 4 CONTROL ROD LOCATIONS I R P N M L K J H G F E D C B A 180*

Loop C , Loop B 1 Outlet inlet

- A D A 2 N-41 SA SA SP l N-43 3 l

C i 4 I

C B , 3

~~

SP SB SP SB I I 5 I

~-

A B D C 0 B A 6 Loop B I

Loop C I ' i inlet SA SB SB SP SA

Outlet 7 90*- 0 C C D - 270' 8 SA SP SB , 58 SA 9 I

I A B D C D B A 10 SB SP SB SP 11 C B B C 12 SP SA SA 13 N-44 N-42 I A D A 14 Loop A af I

N LooD A 15 Absorbe r Outlet inlet I Ma te ri a l Ag-In-Cd Function l

0, Number of Clusters Control Bank D 8 Control Bank C 8 I Control Bank B 6 Control Bank A 8 Shutdown Bank SB 8 I Shutdown Bank SA SP (Spare Rod Locations) 8 8

I I

I I e i

I I

Section 2 BURNUP FOLLOW I

The burnup history for the North Anna Unit 2, Cycle 4 core is graphically depicted in Figure 2.1. The North Anna 2, Cycle 4 core achieved a burnup of 15,934 WD/MTU. As shown in Figure 2.2, the average load factor for Cycle 4 was 87.6% when referenced to rated thermal power (2775 W(t)).

Radial (X-Y) burnup distribution maps show how the core burnup is shared among the various fuel assemblies, and thereby allow a detailed burnup distribution analysis. The NEkTOTE' computer code is used to calculate these assemblywise burnups. Flo re 2.3 is a radial burnup distribution map in which the assem' lywise burnup accumulation of the core at the end of Cycle 4 operation is given. For comparison purposes, the I. 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 is also given. As can be seen from this figure, the accumulated assembly burnups were generally within 4% of the predicted values. In addition, deviation from quadrant symmetry in the core throughout the cycle was no greater than 10.29%.

I 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 predic' ions 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 2, Cyclo 4 followed design predictions closely with each batch deviatirig less than 1.8% from design.

E

I I

Symmetric burnup in conjunction with agreement between actual and predicted assemblyvise burnups and batch burnup sharing indicate that the Cycle 4 core did deplete as designed.

I \

I I'

I I

I

!I I

I I

I I e

I I

NORTH ANNA UNIT 2 - CYCLE 4 CORE BURNUP HISTORY 17003 16000 p

15000 I 14000 C 13000

~

/

'f I'

Y C 12000 '

/

L E 11000 /

B 10000 '

U /,

R 9000 g 8000 7 7000 I M H 6000

[

0 : /

I 5000: [

T 4000 /

Il 3000 2000 r

/

I 1000 0-I O I

0 O

i N

O 1

O O

1 J

O 1

F O

N 1

O 1

9 O

1 M

O J

1 O

1 J

O 1

A O

S 1

O 0

1 O V 1

N 1

O O

1 J

O F

1 O

1 M

C 0 E A E A P A U U U E C 0 E A E A T V C N B R R Y N L G P T V C N B R I 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 6 G G T!MEtMONTHSI CYCLE 4 MAXIMUM DESIGN BURNUP -

16600 MWD /MTU

BURNUP HIN00W FOR CYCLE 5 DES!GN - 150C0 TO 16600 MWD /MTU I

I I

Figure 2.2

~'"^

I $"E^lSll7to4o,c1oas a ""::":

I ee -

I' eo .

I x-I ao -

I so -

I '"-

so -

g 2o .

g g

o 5 5 su l 3

!!!!!!?!!!!!!!!! !

I

E 1

I ' " '"" " 'a"I!!!!!N!!!!!s !!!!!!!!!N!i!!!! !" E5br E

I 1e

I I

Figure 2.3 NORTH ANNA UNIT 2 - CYCLE 4 ASSEMBLYWISE ACCUMULATED BURNUP I MEASURED AND PREDICTED (1000 MWD /MTU) i I R P N M L M J M C 2 E O C 8 A

1 l 24.tSi 22.148 24.971 1 MEASUAfD l I I. 2

.... ...........s .2 4. 26.1... 2.1...96.

8 26.391 29.321 16.391 28.861 16.211 29.511 26.161

... 8 2 4 . 2. 6.l ............ . . .i..Pa

.. to..l

. ....C.7 E D l 2

.......1 26..4S..i.29. 54.1.16 . . 651 28. . 998.16.. 651 29. 451.......

. ..58.1 26.

3 $ 26.97 5 16.58 8 17.92 8 33.131 18.991 32.971 18.391 16.771 26.961 I

3

........I.27.061.17

... .. . ... 208.18

. .. 641.33 601.19 ... . .. 698.33 601.18 ... . ..681.17.20.1

... 2.7 061.......

4 1 27.008 28.088 19.111 36.128 19.831 37.03) 19.731 36.300 19.241 28.45l 26.591 4

.......1 26. .

9.71

. 28. 6.18.19

. . 55.1.36.... 4 t .1. 20.

. 321... .3.7

. 141 20. 32.1 36. 411.19. 55.1

. ... . 9.71.......

28. . 6.11 26.

S I 26.2St 17.011 18.915 38.641 19.625 33.738 36.S44 33.931 20.241 39.161 19.13l 16.728 26.751 S I

l

. 26. 441.17.111.19.471.39

... ..... ..... 101

... .. 20 2.28.13 ...861.36

. .. 521.33 . .86.1

... . 20...228.39 104.19

. .. ..... 474.17.111 26 441 6 1 l229.361 18.621 36.391 19.871 40.241 20.421 40.698 20.491 40.881 19.998 36.021 18.181 29.301 6

......... 9. 518.18.. .. 66.1.36. 421. 20. 2.51

..... . . 40. 551 . ..20 .. 381

.. ....40..231 20. 381 40 ... 55.1

. .. 20.2.$.1.36 5.11.......

.. 42.1.18. . 461 29.

7 1 24.328 16.471 33.751 19.971 33.748 20.131 40.661 20.431 49.831 20.701 33.S01 19.331 33.081 16.28f 24.171 7 I 1 ......

24.111.16. 6.51.3 3 64.1 20. 3.31.3

. .... .. ...3.. 821 ... 20 441 40 .. 52. ..l.20. 221 40. $2.l.20.441.3

.. .. ... . 3 821 . 20.. 3 31.3 .....3 6.41.16. 691 24.116 8 l 22.45 l 28.95 8 19,46 l 36. 781 36.64l 40.46 ) 20.$31 39.881 20.34 8 40. 331 36.801 36. 30) 19.241 28.928 22.168 8 1 22 . ..131 29 .031.19

.. ... .. .... 691.37.008.36. . . ...911 40.2.30 .... . 20.241.39

.. 438.20.

.. .. 28.1

. . ..40 231.36 9.18.37.00.1.19

. .. . 691 29. 0.38 22.131 9 l 24.47) 16.241 32.638 19.901 33.728 20.101 39.451 20.024 40.251 20.380 33.481 19.72) 33.711 16.581 23.961 9 l2

...4 111.16 6.51.33 644 20. 338.33 .. . 821 20...441.... 40 .521 .. 20.226 40 ... 52.l.20. 441 33 821 20. .. .336.33 648.16 6.51 24.181 I

10 1 29.421 17.881 35.931 20.418 40.621 19.750 39.771 20.011 40.431 19.978 86.411 18.66l 29.891 10 8 ..29. S.11.18. .

66.8.36

. ... 421 20. .. 2.51

.. . .. 40. SS.I.20.

. 388 ... 40.

. . 231 20.381 .. 40. 5.%.).20

. ... .. 251.36. 428.18 66.1 2.9 5.11 It i 26.451 16.821 19.30 f 39.231 19.691 13. 371 35.86l 3 3. 391 19.901 39.091 19.4 81 17.001 26.961 11 1 26 441.17.118.19.

. ... ... . .4.71

.. . 39 10.1 20... 22.1 33 86.1.36. .. . 528 33 46..l.20. . 22.1.39.

.. . ... 10.1.19.

.. .. 476.17 111 26 448 I

12 l 21.321 28.57 8 19. Sal 36.101 19.561 36.111 19.S41 35.961 19.171 29.141 27.031 12

.s.26.

. ... 971 28 6.11.19. .. 551.36

. ... 4 81 20. .. 321.37 ... tel.20.

.. .321.36

... .. 418.19

.. . . S.S.I.28

. . 6.91 26 97 8 13 1 27.071 17.12l 18.218 32.441 14.9 81 3 3.241 18.031 16.641 27.091 13 1 2.7.06.l.17

.. .. 20.1.18

. . 688.33 .. .608.19

. . 694.33 60.8.18. 68.1.17 .208 2.7.06.8 14 l 26.801 29.871 16.391 28.631 16.0S$ 29.28) 26.158..

I 14

. 26.. 451

.. .. 29 581.16. 6.51 28 . 991.16

.. . 6.51 2.9 ... 581.. 26 4.51 15 l 24.328 22.168 24.091 IS

.I.2.4.261

... . 29.964

... 2.4 268 ..

I - ' - " ' ' ' " ' ' ' - ' - ^

I I

I "

e I

I Figure 2.4 NORTH ANNA UNIT 2 - CYCLE 4 I ASSEMBLYWISE ACCUMULATED BURNUP COMPARISON OF MEASURED AND PREDICTED (1000 MWD /MTU)

I A P 4 M L K J M 0 F t 0 C 8 A I 2 1

...............s.

l 24.191 22.14l 24.971

0. 45.1. 0. 808.

. . . 2 1 26.391 29.321 16.394 28.864 16.211 29.Sil 26.161 92.1..............

1 n(Asunth 1

.I.n/.P

.. . 1..O t i f.....4 2

1

.......1.-0. . 2.51.-0.

. . .8 .71.*.t

. Sa..l. .*0.

44...

... 0.-2. 66.1.-0.

. ... ..2 41..*.t . 9 0.1.......

3 1 26.978 16.581 17.921 I. 4

......... 0.

1 27.000 2 ..

l 311...3 S81..+4.09.1.33.13 0 18.99 8 32.971 14. 39 8 16. 771 26. 961.. 341. .3.,54 1

.. . .. . .. .1. 88. 8...t ...541.-2

.. ..48 . 4.=0.

19.24l 28.4Si 2 34 4.......

3 4

8.

I

.......1. 0. 09.1. 0.041 19.111 . . .. . 36.121

. .. .. 19.831 37.031 19,731 36.30).. 1 861..-2..,2.31..-0. 80 6. 2 40.8.-0. 2 I

S I 26.2Si 17.015 18.981 38.648 19.681 33.731 36.54l 33.931 20.241 39.161 19.131 1 5 1.-0.

. .. 74 4..-0. 59.1.

. ... .. ..2. 44 4..1.16.1..2. .. 4 .39.1.

5 8.+.0. 0. 06.1. 0. .2.10.. 0. 14. .0. 0. 15. 75

.. .. 6.

8.=..t 6. 721 26. 7512 30.6..1.16..l 6 l 29.361 18.628 36.390 1 6

.......8.-0. ..

30.1.-0. 201..-0. 10.1. 9.878 l

. .. . .... .. .40.241 20.421 .. . ... 40.691 20.491 40.881 19.998 16.028

. . . . .. 731.......

I 7

l 24.32l 16.478 33.751 19.971 33.74) 20.131 40.661 20.431 41.831 20.701 7 8

.i. 0. .85...8. .1.09 8...0....

1 22.451 28.951 19.464 321...1. 79 8..+0. . . .2.31. .1 . 491... 0. 3 31...I. 1.2.7

.06.1..3

. 8.33.

231

0. .. 501 19.

95.1..4.9.31.*..I.69.1..2. . 3 31.2.10.3 3.08 0. 231 8 16.281 24.171 a

.i..1.481.-0. .2.61.

.... . .... .1.171.36.781

0. ... ..... 72 0...0.. 36.648 581.+0. 40.441 20.531

5. 7...8..1.2.41..1.131. 0. 29..). 0.

39.88l 2.S.u...+.0.

30.1..1.89.s.*.2.

20.34128.1..+0. 40.33l3S.i.

36.801 0. 101 36.30l 19.241 28.921 2 9 ...

l 24.4 71 16.24 8 32.631 19.901 33.72l 20.101 39.451 20.02 8 40.251 20. 38 8 33.481 19. 721 33.711 16.541 23.96 I

9 10

.i ..1. 4 7 8..2. 45.1.*.3 0.11.-2.111..0.

1 29.421 17.881 35.931 20.491 40.628 1

29. 5..1.. .641.+.2. 6. 91..+0. . . . 98.1.+0. . . .. 68 4.+.0. 65.)

.. 2. 7 8.+.1 02 4.*.l 00. 4. 0. 20.

to

.i.*.0. .. ...... ..1.

321.-4.181. ...361.

. ..0 76 8....0.141. 9,75 l 39.77 8 20.018 40.431

.1. 82 4..-0. 291..1 42 8..+0. 0.3.:.

19.974 36.41l 18.661 29.8913

. .. 0. 0.16..1.29. 6 101. .1.141.

11 l 26.451 16.821 19.301 39.23l 19.691 33.371 35.861 33.398 19.901 19.09 19.411 11

1. 0. ...04 8..a .....l .....70 8.-0. 8 ... 71. 0. ..341.*2

.. . . . .1.

621.*.t. .. 814.

.451. . . .1 40. ... .8...1.55

.... . *0. 8.+0. 29. 0. 8.17.02 :l0.00 68.l.

.. ... 0 26. 561 44l 12 1 27.321 28.571 19.54l 36.101 19.565 36.118 19.548 I 13 l 1

.... 2 71..+0. 16. 4.-0. 0.3...8.-0.

... . . . .... . 86.1..3 .. 72478...t l

8.-2.

... . . 94..l7 ...t 71..3

. . 99. 8.8.31.3 12

0. 20. 65.961 19.171 29.14 l 2 7. 0 31 1 27.071 17.121 18.219 32.84l 18.911 33.248 ===............... Il

.l. 0.. 06..).-0.

..... .. . 461..+2.3.21.+2. . ... ... . 3 261. . .3 - 941.a l .0.7 4.18.0 31 16. AVC64 i 5 2 7.091 I

... . 50.8.-3 . 271.. . .0. 121 ..

l AR17Mn(71C 14 1 96.800 29.878 14.391 28.631 1 .I.PC7

.... 01 F F ==0.

...... .. 88.l 14 l 1 15 1 $7ANDA80 Otv i

.... 311. 0. 9.71...I .S.a..l

... . . .. ..1.

.3 S.7 4. 251.

... .1.00. 6.. 6.051

.. t..12 8 29. 281 ............... 26.151 l 24.32l 22.164 24.09 I Avc Aes Pc7 1 15

.i . ...=.1

. 04.....i

. .s. 0. .211..0. 90.1.-0.

. .. 69} 1.O.lFF e. .....1.29..l I

A P W M L E J ,

H 0 F E O C 8 A I

BURNUP SHARING I l BATCH (MWD /MTU)

CYCLE 1 CYCLE 2 CYCLE 3 CYCLE 4 TOTAL BURNUP TILT hV = +0.02 I

I 3A3 4A2 SA 13997 0

0 9255 7447 0

11795 17121 0 16623 14555 13538 39875 33797 30659 NE = +0.12 6A 0 0 0 18784 18784 SW = 0.15 CORE AVERAGE 15934 SE = -0.09 I

I 12

I I

Figure 2.5 NORTH ANNA UNIT 2 - CYCLE 4 SUB-BATCH BURNUP SHARING I SUB-BRTCH SYMBOL 3R3 GIRMONO 4R2 SOUR 6E SR TRI9NGLE SR STAR 44000 '

I 40000 I, . /

7 36000 #

gf E -

S #

U 32000 ^' ' #

IB _

g /

_ /

^' '

s r

-/'

/

A-R 28000 " # " ' ' ~

g / / /

I. [

m ? Y A H - ' #

8g U 24000

-d' f -

. /

/ . /

20000[-2 y p # #

/ /

M 16000 *

/

0, f M 12000 '

U #

~

8000 '

j 4000 , /

.. [

I 0-*'

O 2000 4000 6000 8000 10000 12000 14000 16000 CYCLE BURNUP MWO/NTU g m

I Section 3 I \

I REACTIVITY DEPLETION FOLLOW I

1 l

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 consideratior. control rod position, xenon and samarium concentrations, moderator temperature, and power level. The normalized critical boron concentration versus burnup curve for the North Anna 2, Cycle 4 core is shown in Figure 3.1. It can be seen that the measured data typically compare to within 30 ppm of the design prediction. This corresponds to less than i0.22% AK/K which is well within the 1*. AK/K cri'.erion 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.

II lI

,I I

I 14

I Figure 3.1 NORTH ANNA UNIT 2 - CYCLE 4 I CRITICAL BORON CONCENTRATION vs. BURNUP (HFP, ARO)

I X NERSUREO -

'RE0!CTED 1800 1600 C

I R I 1400' T

I R

L 1200,

\

O 1000' N I N C

h..

g I 800 '

N C \

E W

N : ^p R 600 R %

T % .

I I N 400[

E P -

3 : %

{ \

200' I -

0- %

,I .-

2000 4000 6000 8000 10000 16000 0 12000 14000 CYCLE BURNUP (MWO/HTUI l

I I

I Section 4 I POWER DISTRIBUTION FOLLOW I

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 dis ributions 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 2, Cycle 4 is given in Table 4.1. Power distribution maps were generally taken at monthly intervals with additional maps taken as needed.

I 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 sbws a map that was taken at the end of Cycle 4 life. The measured re l ai.

ve assembly powers were generally within 4.5*. and the average percent dif ference was equal to 1.9*.. In addition, as indicated by the INCORE tilt factors, the power distributions were essentially symmetric for all cases.

I An important aspect of core power distribution follow is the monitoring of nuclear hot channel f actors. Verification that these f actors are within l 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 4 Technical Specifications limit on the axially dependent heat flux hot channel factor, F g(Z), was 2.20 x K(Z), where K(Z) is the hot channel 16 I

i l

factor normalized operating envelope. Figure 4.4 is a plot of the K(Z)

I 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 4, tha measured values of F q(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 measured during Cycle

4. As can be seen from the figure, there was an 18.6*4 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 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. For the majority of Cycle 4, the enthalpy rise hot channel factor licit was 1.55 x (1+0.3(1-P)) x (1-RBP(BU)), where P is the fractional power level and RBP(BU) is the burnup dependent rod bow penalty. On October 24, 1985, the Nuclear Regulatory Commission issued Amendment No. 55 to the Operating License for North Anna Power Station and eliminated the rod bow penalty.

Therefore, at the end of Cycle 4, the F-delta-H limit was 1.55 x (1+0.3(1-P)). A summary of the maximum values for the Enthalpy Rise Hot Charnel Factor measured during Cycle 4 is given in Figure 4.10. As can be seen from this figure, the smallest margin to the limit was in the middle of the cycle and was equal to approximately 6.6*..

I 17

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 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 pueer shapes due to xenon redistribution are avoided.

The plot of the target delta flux versus burnup, given in Figure 4.11, I shows the value of this parameter to have been approximately -2.5% at the beginning of Cycle 4. After approximately one-third of the cycle, delta flux values had shifted to -4.0% and then moved to -3.5% near the end of Cycle 4. At the very end of Cycle 4, the delta flux values rose dramatically to approximately +2.5% due to the coastdown. 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 N2-4-07 (Figure 4.12), taken at 230 WD/MTU, the axial power distribution had a shape peaked slightly toward the bottom of the core with a peaking factor of 1.20. In Map N2-4-23 (Figure 4.13),

taken at approximately 7,900 WD/MTU, the axial power distribution had become more peaked toward the bottom of the core with an axial peaking factor of 1.16. Finally, in Map N2-4-38 (Figure 4.14), taken at approximately 15,250 WD/MTU, the axial peaking factor was 1.11, with a slightly concave axial power distribution. The history of F-Z during the cycle can be seen more clearly in a plot of F-Z versus burnup given in I

Pt-Pb I

Delta Flux = ----- X 100 2775 where Pt = power in top of core (W (t))

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

18

I Figure 4.15.

In conclusion, the North Anna 2, Cycle 4 core performed satisfactorily with power distribution analyses verifying that design predictions were accurate and that the values of the F (Z) 9 and F-delta H hot channel factors were within the limits of the Technical Specifications.

I E. 4 I

I 19 I

W W W W W .

M M M M M M TABLE 84 .1 NORTH ANNA UNIT 2 - CYCLE to

SUMMARY

OF INCORE FLUX MAPS FOR ROUTINE OPERATION I I I I J 1 ,1 2 i i l l l BURN l l ll F-O (T) HOT i ! F-DH(N) liOT CORE F(Z) I is l .

t l UP .I DANK CHANNEL FACTOR l' CHNL. FACTOR MAX '

31 QPIR ,

1 AXIAL l' NO.l I MAP DATE l MWD /I PWR' D I F(XY)l OFF l 0F 1 1 NO. l MTU ' (%)l! STEPS, I AX1ALll l 1 1 IIAXIAL. i il MAX l i SET THIMI I i .ASSY PINI POINT F-Q(T)

ASSY l P I N I F-Dif( N ) lPolNT

." F(Z)l 1 MAX l LOC (%) , BLESI l l __ i __ li 1 1 i 1 l __ . l l l .

H ; : I _._1 ,,

1 l il I I l l 7 1.11-16-841 230a100 . 216 P07 l OG 37 1.789 I P071 OG l 1.420 37 '1.20311.49311.0151 NW1 -2.411 16 1 4 18 12- 7-8fel It60L1001 228 ll L13 ' kOI 3T 1.723 1 1131 kom 1.375 38 1.19711.475l1.010. NW1 -2.881 44 49 l l 9( 5) 12- 8-88si 108'a il100 221 l L13 I KO 37 .11.736 .I L131 KO 1 . 3 784 i 38 11.21011.47311.01841 NW1 -4.301 50 l 113( 6)l12-19-88s1 117011100 206 ! L13 l ko 37 1.780 4 L131 ko 1.388 1 38 11.20111.875l1.0091 NW1 -3.531 50 l 4

116( 7)I 1- 8-851 1967 l100 ' 217 l L131 kOI 37 1.733 . L131 kol 1.386 '

38 11.20111.49011.0011 SWI -3.531 8 8 l 4 y i I I 1.__ l l

__. i 11 L l _ _ l __ . _._._ .

1. l l l_I 1 I o

NOTES: HOT SPOT L OCAT IONS ARE SPECIF IED HY CIVING ASSIMBLY LOCATIONS ( E.G. H-8 IS THF CENTER-OF-CORF ASSEMBLY),

FOLLOWED BY lHE PIN LOCATION "Y" COORDINATE WiiH THE SEVENTEEN ROWS OF FUEL RODS LETIERID A TilROUGH R AND IHE [X" COORDINAIE D[SIGNAIEDDENOTED IN A SIMIL AR MANNER). BY THE IN THE "Z" DIRECT ION Tile CORE IS DIVIDED INTO 61 AXtAL PolNTS 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 1.0f4 .

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

( 4). QPIR - QUADRANT POWER TILT ratio.

( 5). MAPS 10 AND 12 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

( 6). MAP 11 W.... J,80RTED DURING AQUISITION AND NOT ANALYZED.

( 7). MAPS 14 AND 15 WERE TAKEN FOR INCORE/EXCORE CALIBRATION.

m M M M M M M M e m m W W TABLE I4.1 (CONT.)

l l h BURN.. F-Q (i) H01 F-DH(N) HOT CORE F(Z) l l 4 l l l OP BANK CHANNEL FACTOR CHNL. FACTOR 11 MAP

DATE PWR D MAX l 31 QPTR l AXIAL l NO.

MWD / l F ( XY ) l l OFF OF NO. I MTU (%) STEPS l ,

1 AXlAll l

AXIAL MAX l l SET THIM l l l lASSY PINI P0lNilF-Q(T) ' ASSYl PIN; F-DH(N) cPOINT. F(Z) MAX LOC: (%) BLES I 1 _t _ _ _ . __l l .

I l 2-19-851 3218L100 111 220 101 1.710 l __I P.1.389 _

Jll 38 G06 38 1.182: 1.483. 1.008 __.NW I -3.15ll 46 l 118 1 3-21-851 84257 100 224 FOT Jl l 38 1.703 F07 Jll 1.398 38 1.17011.497 11.005 NWL -3.02 48 l 121( 8)l 5- 3-851 5:414 1100 221 I LIO Ji 39 1.711 J08 ' Hil 1.413 46 '1.16311.505 11.001 : SW1 -3.79 18 l 4 122 H 6- 8 -851 6610 H 100 8 220 I L10 IJ I6 4 11.698 I F07 J11 1.418 46 1.158LI.508 l 1. 0084 NEl -3.811 16 4 l 123 l 7- 8-851 7906'100 222 f051 HI 46 1.710 F07l Jll 1.f422 87 .l1.158 1.505 1.0081 NEl -8,101 47 4 4 126( 9)l' 8- 9-851 81184 100 ' 226 C06 IJ l 47 1.6T7 F07 Jl. 1.430 47 ' 1.139,1. 5 32 )l l . 00 T L NEl -3.05 ; 39 127 9- 9-85110083 100 1 228 F051 til ta l 11.689 IO 7, LK, 1. f4 22 48 1.14611.506l1.006 NLl -3.66l: 85 4

. 28 .110-10-85111?61 1100 ! 228 F05 1 Hil 47 '1.697 TOT;: I kIl 1.8284 88 4 1. 184 2. 1.50111.004 ! SE -3.21 l 19 29 110-Pis-85111:46111100 ; 227 fili. Ill i 88 4 1.787 4 F11 HI i 1.4?9 ,1 88 4 , '1.156 ;1.51711.00141 SEi ' -4.82 ; 42 ll 4 4

l 32( 10 ) l 11 8511??pis 100 228 009 Hil $2 1.682 I foil LK,' 1.418 53 1 . 1843 l1.50911.009 1 NE -3.f:51 46 i33 :

12-16-85113510 100 228 C06 kl 1 53 1.683 F05;; 111 l 1.8014 53 1.150l 1.88911.010L NE -3.88: 83 4 4 4 (

1 38 1-18s-86118 612 100 228 4 E10 i IJ ' 53 1 1.674 F09; MF. 1.399 53 '1.1581!1.481'1.00611 NE ' -3.551 85 i N I31(11)I 1-18-86118:736l 100 217

TOS : IJ 53 1.761 F05 I IJ 1.395 53 l1.218 1.8 70 1.0191 NEI -6.984 4 40 l 138 ; 1-31-86115257 95 228 I F05l HI, 13 1.624 fil, HI 12 1.106 1.48511.0101 NE 1.f034

-0.57 1 39 l 139 2-10-86115600 88 228 l. F11 Hil 11 1.699 Fil Hl. 1.8054 12 11.14911.89611.0091 4 NE, 2.591 39 l l I l __ - l ___ l _I l l l l ;

l ___ ll l l

( 8). MAPS 19 AND 20 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

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

(10). MAPS 30 AND 31 WERE TAkEN FOR INCORE/EXCORE CAllBRATION.

(11). MAPS 35 AND 36 WERE TAKEN FOR INCORE/EXCORE CAllBRATION.

I I

Figure 4.1 I NORTH ANNA UNIT 2 - CYCLE 4 ASSEMBLYWISE POWCR DISTRIBUTION N2-4-07 I

. . . . 1 . a . . , t . . . .

. . ...8.=..

. m.m . . . 48 . 0. .? . ..44.. . co.sm t . 1

.9CT 91FFEstett. S.4 .8CT SIrristsCt.

I

5. 5 . 3.9

. S.47 . 9.71 . 4.09 . 1.01 . 8.99 . 9.71 . 9.47

. 9.44 . 9.74 . 1.18 . 1.03 . 1.11 . 0.73 . 0.47 t

. 3.1 . S.4 . 8.0 . 8.9 . 1.6 . a.8 . 0.8 .

0.95 . 1.10 . 1.18 . 1.14 . 1.89 . 1.14 . 1.15 . 1.18 . 0.58 .

0.55 . 1.19 . 1.14 . 3.15 . 1.29 . 1.14 . 1.14 . 1.10 . 9.94 3

. 0.8 . =0.1. 4.4 . 0.4 . -0. 0 . .c.S . 8.9 . =0.1 . *1. 9

. 0.04 . 9.95 . 4.19 .1.21. 3.41. A e t .1.31.1.31.1.19 . 0.95 . 8.34

. 0.55 . 0.94 . 1.19 . 1.85 . 1.85 . 3.1.19.1.88.1.14.0.99.0.93. 4

. 1.4 . 0.9 0.7 . 1.1 . 0.4 . 1 . 1. 7 . 9.8 . =0.9 . =1.3 . *1.6 .

9.47 . 1.99 . 3.14 . 1.86 . 1.16 . 1.14 . 5 ' 1.14 . 3.16 . 1.06 . 3.18 . 5.99 . S.47 I .

. 0.47 1.11 . 3.1a . 1.06 . 1.le . 1.39 . 1 as 1.1 . 1.1 . =4.3 . =0.7 . =0.4 1.19.1.37.I.es.1.17.1.0a.0.47.

0.7 . e.e . e.S . 6.4 . -0.3 . -0. 9 . =4.4 4.4 0.71.1.18 . 4.81.1.17 .1.03 .1.te .1.e8 .1.30 .1.03 .1.17 .1,81.1.1S . 0.71.

. 0.73 . 1.te . 1.83 . 1.14 . 1.03 . 1.81 . 1.04 . 1.31 . 4.04 . 1.14 . 1.19 . 1.13 . 0.71 .

. 8.4 . 8.7 . 1.8 . =0.4 S.3 . 8.9 0. 9 . 0.9 1.4 . -4.9 . *1.4 . *1.5 . 0.4 S

6 I . s.44 . 1.09 . 1.14 . 1.11 . 1.18 . 1.36 . 1.08 . 1.18 . 1.03 . 1.29 . 1.38 . 1.81 . 1.34 . 1.99 . 0.48 .

. e.44 .1.14 4.6 . 4.8 . 4.4 1.19 .1.t2 .1.17 .1.te . 5.04 .1.19 .1.85 .1.84 .1.17 .1.17 . 3.12 .1.00 . 0.42 .

0.8 . 4.4 . =0. 5 . 1.1 . 1.8 . 0. 7 . 8.6 . =4.9 .

S.6 . *0. 5 . *1.4

. 0.84 .1.01.1.te .1.38 .1.19 .1.06 .1.18 . 0.9' .1.34 .1.06 .1.19 .1.88 .1.89 .1.01. s.54

. S.Se .1.04 .1.29 .1.25 1.81.1.07 .1.28 . 0.98 .1.17 .1.95 .1.16 .1.18 .1.17 .1.98 . 0.56 G.4 7

8

. 4.5 . 4.4 4.4 . 1.8 . 1.5 . 1.4 1.3 . 0. 7 . -0.9 . -1.0 . .t.e . = 5.e . =8.4 0. 7 . 3.0 .

I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. e.48 .1.09 .1.14 .1.81.1.18 .1.30 .1.e4 .1.14 .1.98 .1.89 .1.14 .1.81.1.14 .1.09 . 4.48 .

. 9.44 .1.11.1.12 .1.8f .1.30 .1.89 . 0.99 .1.16 .1.01 .1.18 .1.14 .1.19 .1.13 . 1.11 . 0.44 4.e . 4.4 . 4.s . s.S . 1.6 . -e.1 . -3.5 . 4.6 . 1. 5 . 4. 7 . 4. 7 . 4.4 . -4. 9 1.8 . S6.

. 0.71.1.15 .1.81.1.17 1.03 .1.89 .1.08 .1.39 .1,43 .1.17 . 3.33 . 3.15 . e.71.

9

. 0.79 . 1.13 . 1.88 . 1.19 . 1.03 . 1.17 . 1.84 . 1.17 . 1.91 . 1.15 . 1.23 . 1.19 . 6.73 . as

. *1.0 . ~4.8 . 9.7 . 8.1 . 9.1 . -4.8 . *1. 3 . .t.8 . 1.7 . *1.6 . 0.9 0. 5 . S.8 .

. 8.47 .1.99 .1.14 .1.06 . 4.16 .1.14 .1.19 .1.18 .1.14 .1.06 .1.14 . 4.09 . e.47

. 0.47 .1.10 .1.29 .1.00 .1.13 .1.15 . 3.14 .1.15 .1.15 .1.98 .1.19 .1.3e . 0.47 Il 0.9 0.9 1.3 . 4.1 . 1.5 . 8.8 . 4.3 . .t.8 . 4.9 . 4. 8 . 0.6 . e.3 . 0. 7 .

..........................=...................................~....................

. 0.84 . 0.93 . 1.19 . 1.81 . 1.41 . 1.22 . 4.21 . 1.81 . 3.19 . 0.91 . 9.94 I . 9.96 . 9.96 . 1.81 . 1.30 . 1.14 . 1.19 . 1.17 . 1.19 . 1.17 . 0.94 . 9.94 5.4 . 2.9 3.1 . 4.8 . -4.1 . -4.6 . -8.8 . *1.6 . 1.1 . 9. 7 8.56 . 1.14 . 1.15 . 1.14 . 1.89 . 1.14 . 1.15

. 9.54 .1.11.1.13

. 8.8 .

1.10 .1.16 .1.le .1.13 .1.e4 . 9.SS .

0. 8 . *1.6 . = 5. 7 . = 5. 7 . -3.8 . -3.1 . -1.6 . 8.1 .

1.18 . 0.88 8.1 .

18 IS I

. 0.47 . 0.71 . 1.99 . 1.01 . 1.09 . 0.71 . 6.47

. 0.47 . 9.75 . 1.11 . 1.68 . 1.06 . G.49 . G.44 . 14

0. 3 . 3.4 . 1.1 . 0. 7 . 5.8 .

B.4 . -3.1 .

STafeae8 . . e.44 . 4.54 . e.48 . avstaat .

. OtvIAfttes . 9.45 . 0.57 . 0.45 . ..FC7 91FFteteCf. 18

.a. nS1 . 8.7 . S.e . B.7 . . a.7 I .. .

SUMMARY

I MAP NO: N2-4-07 DATE: 11/16/84 POWER: 100%

CONTROL ROD POSITIONS: F.Q(T) = 1.789 QPTR:

D BANK AT 216 STEPS F-DH(N) = 1.420 NW 1.015 I NE O.996

...........l..........

F(Z) = 1.203 SW 1.001 i SE 0.988 I F(XY)

BURNUP =

= 1.493 230 MWD /MTU A.O = -2.47(%)

I 22 I

i I ,

NOB 1H YNNY nNll Z - 3A373 P VSS3WGl AMIS 3 DOM 3W GIS181801lON NI-t-ZE 3 0 3 9 9 e a m 1 a f m 9 4 e

9 13

e'ot

ea3433&39 seltt3dna

e **1 ent sneaS ** 1

na vEW&S *

G *93

s' tl

e'tI * *ya etdageer33'

d34 STdeleG3B*

19* t t'9 *

..........................'9* . . . . . . . . . . . . . . . . . . .. . ..

' G*ed

0 99

t'et

s'tt

t*et

e 99

s'ed * *

e'9 4

S '99

t 'ee

e

63

1

e t 1*

eg 9 6*D . 'e d *

G *t * -t*6 b*0

b*1 * -e'l * . g.g 1 s t

- e*6e 8'59* ' 1'09

1'19

1*eS

1* 33e*6* *1*e *eW 3 * .1* 1t *19 .

1'09

s'et *

*t*$ ** 0-t'09

1*t1

t'et

1'11

t'ed

**

0 * **

4 * **

t * -9

...............................................'9* . . . . .*

. . . t. . *td

.

t *e9 *....................'et*

0 69

8 ' 61

t ' tI

1* t d

1' 8 4

1

19

1* 8 4

t 14

t " tt

G

41

e

G*

e

e'6*

9'41

1'81

1 14

1 39

t *t*

t

tS

1'ts

1*43

e*61 9* es'st . *

e*g * -D **

e s

e l

b t

b 9 * .t*d

t*4

e *t . .e 1.

. . . . . . . . . . . . . . . . . . . . . . . . . . . ' . . . . . . . ' . . . . . . . ' . . . . . . . ' . . . . . . 3. . . . . . . . . . . . . . . . . . . . . . . . .

s'ed

t se

1*t1

t ed

139

t*tS

1*10

t*le

139

1 ed ' t'tt

1*eS

0 04 *

e'99

1'09

t'16

t *09

1*39

1'16

1*TS

t'3e

t tt

f 09

t*88

1*et

0'ed 4* 4 **

F*t* I"9

b 9

b 9 * *9 *6

t*S

1'4

3G* 8 *t

t*t

e

E * -e's

t '39

1*ed

t*ES

1*eS

l t9

1*04

l te

1'l A

l*19

e 99

9

- e' S de'99* *t *t"19 t9

f* 19 l'td* ' t*3d

3

ed

t *tt

1*e9

113

1*10

1'*39

t't9

1* te ' e96

3 *(

8* f

e*t

e'9

9*9

1*6

3*t* te* st* e

f * -t

8 * .t.e = 33.

G **1

l'e1

t'09

1*84

1'19

t'39

1*49

1*34

tw

1*39

1*t9

t *84

1* e9

101

0 *91 *4

s'tt

t'et

t*ed

1'4e

1*t9

1* 3S

1* eS

t'11

1* e6

t *tS

1*t6

t *3 $

1* e9

t'et

s'o,t

8A. ge. gt* g*g . .t+g e .1.3 * .0 t. .

b6 eg. t

...................'t'..b*f'.....*..*..............g..................................................3.

1*f

4*3

e at

1*13

t *19

T*13

t

e9

t 89

t*eR

t *t9

t

09

1*tt

t 19

1* 32

e*41

s 'tt

9

- S'SR S

st

e** s'61

t'31

1 19

l'tS ' 1* ed

ltt

t *4S t9. t.g

t *.tSpot* t'ed

. .g *g1'11 . 1.3

ltI

1*31

. g.g . 3.g* .0 4$

G e R

t*t

4*1

e*4

9*3

s4* t'S . tg. ge.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. . . . . . . . . . . . . . . . . . . . . . . . . . .

S'91

t*tI

1*6e

1*34

t'19

1*39

109

1*31

1'09

1*39

1*19

t'34

1*eS

1*e1

s'ot *

t'ot

e*66

t'et

t

39 1+g * .e 1*16 t = p** tt**39 e*g

t t*t*et**eg* t *39 e *t'.*t*.t*edf ** tg*g

26

t*tS

t* g . 1+g .

t* 39

1 00 ' 1'03

s'ot *

. 1 t '. ..t

. . *. .4. *. *. .t*. f. *. b . .*1

s'99

1'19

1*td

t'39

t'ed

1*39

1*99

t*39

1*ed

1'30

1*td

t*19

s'99

te

s'99

t *tS

1'14

1*tt ' 1*04

1*39

1*e9

t.p'81 e*g . 1+t e et* 9.

1* e ed t .* t.p'34g *.1 tag 16 *.t *td 1.g* -s'd6tg.*

-t

t * - t* * . e 3

...................3........1.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

s'ed

t'eS

t'IT

1'04

1*M

t *19

t *19

1 19

1*3S

1*ed

t'31

1'09

s'ed

tt

S'09

t *4S

t *II

t'e6

t 8 4

1 19

1*13

1'19

1'3e

t'ed

tt*(. t S

taeo

s'ed t.g .*

-e*(

e *t

e '9

l't

0 *9

1 *9

t *S * .1 **

0*e

eg.

...............................=.......=......................................e.

8 et

s 61

1*33

1*td

1* 34

1* t9

1*3 4

t *14

1 33

0 61

o et

9- 13

e'te

e'*4$

l'aS

t'14

1* 3#

1*tt

t

39

f *19

1 3T $*

s'63 1**. g-

e*e, .

8*4* t 3

t * -0

t * -3

..........'9* .....................'t**t't*al'6**1*4*-S*

09

1*t9 ' 1 e9

s'go

6e tE

'* t'ss *a 1* t'ete9* t* ts 1'19

t**et 1* eD* l

t'33

1'eS

1 13

t'et

0e*g 99.

s'1*d

g g . .o e * .g 0 . 3't6 g *.l- 1' 9 . .t.g . 1 g .

6S

t ot

e*99

s *A

te

e *ed

e'99

1*et

s'63

S66

s'91

eeS *

s'ed

. gg* *8*3 e *de

1.e01

e*1 * -e t * .8 t * .t .g . . g 3 . . ...........

.............. . - tanave3 -

smorse ' * . . . . . . . . . . . . . . . . . . ..1 e st

o et - te

e*+s

e'at

e'et * .wd e.tidaman- 10 aa.mnee 1 exE - t d

.t

4 * .e 's -

I SAWWYWA av13* 1/ 9/9G dom 3W: L00%

WVd NO: N2-4-2E 3-011( = L*LLO DdiW:

3ON1801 800 dOSill0NS*

= 6 422 NM O*66G l N3 L*009 0 0vNM Y1 222 S13dS 3-OH)N( ...........l...........

3)Z( = L*LG9 SM 0*669 l S3 O*666

= L"GOG 3)XA(

9AWNnd = L609 WM0/W1n v*0 = -h'L0)%(

I ZC

I I

i I

i Figure 4.3 I NORTH ANNA UNIT 2 - CYCLE 4 i

l ASSEMBLYWISE POWER DISTRIBUTION N2-4-38

. . . . . . . . . F . . . . .

08ESICTES . e.44 . 0.57 . e.44 PW81Cfte .

. seammes .

. e.44 . S.38 . e.40 . . peaSENs . 1

.FCT S!FFleaste.. . 4.1 . 1.1 . 0. 7 . .0CT DIFFleepES.

. e.se . 0.71. 8.08 . 0 e4 . 3.00 . 0.F1. 0.9e .

. 0.38 . e. Ft . R.83 . 0.98 . 1.et . 0. F1. 0. 98 . t

. 0.8 . 3.4 . 0.8 . e.4 . =0. 6 . 92. 0.8 .

I ................................................................

0.57 . 8.es .1.16 .1.06 .1. 25 . 8.se .1.16 . 8.es . 0.87 8.se .1.e4 3.17 .1.07 . 8.23 . 3.es .1.3 F .1.88 . e.Se .

-0. F . =0.8 . 0.6 . 0.8 . -e.1 . -4.1 . 0.3 . 0. 8 . -3. 6 .

. 0. 56 . 0. 98 . 1. 21 . 1. 34 . 1. 27 . 1.13 . 1. 8 7 . 1. 54 . 8. 45 . 0. 98 . e. se .

5

. e . Se . e 98 . 1. 81 . R . IS . 1. 8 7 . 1.18 . 5. 28 . 1.1F . 5. 22 . 0. 98 . 8. M . 4

. -0.1 . =0.8 . 8.4 . 1.2 . e.e . 8.4 . 4.6 . 4.s . e.S . e.0 . -4. 0 .

I. .. e.80 e.49 . 3.e4

.1.e8 .1.25 .1.06 .1.as .1.18 . 8.48 .1.18 .1.te . 5.06 .1.31. l.es . e.se .

1.te . 4.es .1.37 .1.16 . 4.15 .1.&F . 4.34 . 5.07 . 3.81 4.04 0.30 .

. -8.9 . 4. 0 . -e.e . -e. F . -e. 8 . 4.8 . 1.5 . 1. F . 3.0 . 1.8 . -e.4 . 4.0 . e.6 .

S

. 0.71. 8.16 .1.14 . 8.38 .1.06 1.84 .1.05 .1.36 . 8.M .1.28 . 3.36 .1.14 . 8 Ft .

I .0.F3.1.17.

. 0.6 . e.6 1.16.1.8F.1.87.8.39. 1.06.4.50.1.49.1.89.1.84.1.88.e.F1.

0.8 . -0.8 . 1.0 . 31. 3.8 . 2.8 . 4.9 . S.8 . e.e . 4.4 . -e.5 .

. e.48 .1.88 . 5.06 .1.2F .1.15 .1.26 .1.es . 8.36 . 8.06 .1.46 .1.18 . 3.47 .1.06 .1.88 . 4.44

. S.46 . 3.02 . 3.06 .1.26 . 1.E.8 .1.27 4.07 . 3.39 . 1.0F . 3.50 .1. 34 . 5.24 . 1.06 . 1.98 . 0.46 8.8 . -e.2 . -0.1. -G.e . ~4.8 . e.e . 3.4 . 8.8 . 48. 8. 7 . 8.0 . -8.8 . 4. 8 . -0. 3 . 0.6 .

6 F

I .. 0.57 . e.te .1.23 .1.13 .1.18 .1.e4 .1.24 .1.41.1.26 . 4.es .1.10 . 4.13 .1.23 . e to . 0.57 4.54 . e.96

-0.5 . =e. 5 -4.8 1.48. .1.L5 -0. 0 .

. 5.14 .1.es .1.50 . 4.04 .1.28 .1.es . 8.18 . 3.1s .1.23 . 0.90 . 8.8F .

0. 8 . 3.1 . 8. 9 . 5.4 . 4.8 . 1.F . 0. 5 . -4. 4 . -e.4 . =0. 8 . 0. F .

. e.44 . 8.08 .1.06 . 4.37 .1.18 .1.24 .1.se .1.36 .1.06 .1.86 . 5.18 .1.87 .1.06 . 5.08 . e.45 .

. e .44 . 0. 99 . 1.e4 .1.88 .1.18 . 5.88 .1.00 .1.36 . 1.06 . 1.34 . 1.18 . 3.37 . 3.e7 . S.es . 0.46 .

e 9

. -3.6 . -3. F . 4. 7 . 4.3 . e.3 . -e. 9 . -3.4 . 0.4 1.6 . 1.5 . 8. F . 4.1. 0.6 . e.8 . 8.4 I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

.. 0.73 e.69 .1.14

.1.16 .1.14 .1.te .1.06 .1.86 .1.e5 .1.86 . 8.e6 .1.te .1.84 . 4.16 . 0.71.

. -4.6 . *t.6 . -e.9 1.15 . 4.39 .1.e4 .1.24 . 5.06 .1.te .1.07 .1,29 .1.8 7 .1.19 . 0.F3 .

1.0 . 4.3 . -3.4 0. 8 . 3.1 . 1.7 . 3.1 . 3.4

. e.se .1.e6 . 3.11. 3.06 .1.as .1.18 .1.14 . 3.18 . 8.an . 4.06 .1.21.1.es . e.Se .

1. F . 1.7 .

Le

..-0.4.

e.49 .1.F4 .1.81.1.07 .1.25 .1.13 . 3.M .1.18 .1.88 .1.00 . S.85 .1.ee . S.as .

I 14 4.1 .-e.#. 8.0 . -S .S . -5.8 . -8.5 . 5.8 . P.3 . 4.e . 1.6 . 44. e.e .

. 0.86 e.98 .1.31. 4.14 . 3.27 .1.18 .1.27 1.14 . 1.21 . 0.98 . 0.86

. 0. 38 . 0. 9% . 1.te . 3.10 .1.33 .1.09 1.34 1.18 . 1. 22 . e. 98 . 0. 5 7 Et

. 3.4 . 8.8 . =0.8 . ~B.S . -8 5 . -5.8 . .t . 8 . 0.8 . 0. F . 5.5 . S. F .

. 0.87 . 1.08 . 1.14 . I.86 1.25 . 1.06 3.14 . 1.es . 8.37 I .

. 0.57 . 1.e4 .1.14 e.F . =0 0 4.8 . -5.8 . 1.28 5.45 .

t.8.1.48

.............................................=......

. e.N . 0.F1.1.88 . 0. 96 . 8.08 . e. F1. 0.55 .

. 0.49 . e. 71.1.01. 0.95 .1.00 . 0. 70 . e.49

. =0 4 . 4.s . =0.0 . -1.6 . 4.0 . 4.4 . -0.1 .

. 4 0. .4.14 4.s ..1.e4 e.e .. 0.57 0. 7 13 16 I

. STafsbase . . 0.4e . 0.87 . 0.48 . . avg aaet .

es.ytaruse . e.as . e.36 . e.44 15 1.e:1 . . -e.e . . .6 . -a. 6 . .FCF e.!FFleE3Ct.

. a.s I

SUMMARY

MAP NO: N2-4-38 DATE: 1/31/86 POWER: 95%

CONTROL ROD POSITIONS: F-Q(T)

1.624 QPTR:

I D BANK AT 228 STEPS F-DH(N) = 1.403 F(Z) = 1.106 NW 0.999 l NE

..__.......l.___.......

SW 0.988 l SE 1.010 1.003 F(XY) = 1.485 BURNUP = 15257 MWD /MTU A.O = -0.57(%)

I 24 I

I I Figure 4.4 j

I HOT CHANNEL FACTOR NORMALIZED OPERATING ENVELOPE 1.2 I :

(6.0, 1.0)

I.0 - '

% (10.91, 0.94)

I 7l I "': (

I \

I

\

g 0.6 {

I ! .

\

3 I

0.: u2.0, 0.45),

i .

I 01' I

~

I C.0-2 4 6 g I

10 12 CORE HE10HT IFil TOP I 25 I

I I

NORTH ANNA UNIT 2 - CYCLE 4 HEAT FLUX HOT CHANNEL FACTOR, F (Z)

N2-4-07 ,

I I a.S .

I. .

m .. .;

I v y

N HCY

. M M MMMM MM XXXMMMM g - MMM M M XMMM O - IM M MM p . M M M M U . MMM 4e i.S . MMMM M

. M M N I z g

M M M X

o :

I XX s

S M M M

N . X I

D =

d : "

.MM MM g

h -

I E ....

i I 80TTori OF CORE AXIAL POSITION (NODES)

TOP OF CORE I

I lI 26 I

I I s NORTH ANNA UNIT 2 - CYCLE 4 HEAT FLUX HOT CHANNEL FACTOR, F (Z)

I N2-4-23 I

I 2.5 .

I%

Ts ...

v .

I H Cr b $

M =

NNMMMMM MMM O + NXN N MMM MNNMM I

M M MM X X MM MMMM

< =. x M 1.s .

M xMux

k. M MM

X X X p.3

M E :

I X

M c -

E M

P = M I

... . M

_e .

g -x x

D . x d .

x I

s .

14

= ... .

I l ... .

.OTT(M OF CORE

.1,....;,....;,....;,.. .;,. ... . ..;

TOP OF CORT AXIAL POSITION (NODES) l I l

I I

27 I

I I

I NORTH ANNA UNIT 2 - CYCLE 4 Figure 4.7 1

HEAT FLUX HOT CHANNEL FACTOR, F (Z)

N2-4-38 l I !

I ... .

I. Tn s.e +

I v -

i-e Cr =

2. :

e O

I ti 4

ga.

4 1.. +

=

. M M

M MMM M

M M M MMM MM M

MMMMM MM M MMMMMM N MMMMM N N M

MMX MM M

W . M I

MM M

= M M M M M

.M M G =

x H =

I M

C 1.s +

= . M M

h a M

u. -

I <

H k3

% 0.

+

I .

I 0.0 +

I . . . . . I . . . . I . . . . . . . ..I. .t.. .g.. ,g,,,,g,,,g I..

g ,, g = . I..

- = = = ,3.,,,,g,,

, . 3. , ,

TOP OF CORT I AXIAL POSITION (NODES)

I I

I 28 I

i I Figuro 4.8 !

NORTH ANNA UNIT 2 - CYCLE 4 )

I MAXIMUM HEAT FLUX HOT CHANNEL FACTOR, F0 a P,VS AXIAL POSITION F0 s P LIMIT a NRXIMUM F0 s P 2.4 ,

2.2

'N g 1 g 2.0 x

) ,

1- i.,

l

. . . . .. . . . \

,. =...

A O

g ,

..a $

sh 'i

} .4

\

F -

1.2 .\

\

IP 1.0 It I 0.8 1 0.6-t 0.4 I 0.2-I 0 . 0-6 55 50 45 40 35 30 25 20 15 10 5 1 AX!AL POS1T10N tN00E1 BOTTOM OF CORE TOP OF CORE 29 I

E """

NORTH ANNA UNIT 2 - CYCLE 4 MAXIMUM HEAT FLUX HOT CHANNEL FACTOR. F-0 VS. BURNUP

- TECH SPEC LIMIT X MERSURED VALUE 2.4- !

2.3 iM A X

2.2 M

E 'MU 2.1 H

IE A 2.0 T

F 1.9 L

U IX 1.8 x O

IT 'q-E x v x .,

< ^

x C x x x IH R N

N 1.6 x I! 1. 5 --

F I: T 1.4-I "0 1.3 I 1.2-

, s- .. .- .

0 2000 4000 6000 8000 10000 12000 14000 16000 CYCLE BURNUP (MND/MTUI I 30 I

I NORTH ANNR UNIT 2 - cyggg ,

WM A 10 l l

ENTHALPY RISE HOT CHANNEL FACTOR. F-OHtN) VS. BURNUP i

- TECH SPEC LIMIT l X NEASURED VALUE 1.60 I i . s 5 .;

I E 1.50' F

iTH R

1 45 ILP Y

~

X #

x y

X X 1.40 s x **

S : x x E -

H 0 1.35' T-C -

H -

A 1.30' INN :

E -

L 1.25 F

A ICT 0 1.20 -

R I .

1 15 -

I -

I ' " o- .

0 2000 4000 60C0 8000 10000 12000 14000 16000 CYCLE BURNUP (MWO/MTU1 I 3'

I re., 4. n NORTH ANNA UNIT 2 - CYCLE 4 TARGET DELTR FLUX VS. BURNUP 10 I 8 1

I i R

6

'G 4 E

T -

0 :

a E 2 I ;L F 0 IL U X

A

! -2 n . s

^

^ -

IP R -4 "

C En T

-6_

1 E C 2000 4000 60b0 8000 10000 12000 14 BOO 16000 CYCLE BURNUP (MWD /MTU)

I 32 I

I I

Figure 4.12 NORTH ANNA UNIT 2 - CYCLE 4 CORE AVERAGE AXf AL POWER DISTRIBUTION N2-4-07 I

I a.s .

I, .

FZ = 1.203 A. O. = -2.47 s.t . xxxxxx xx,,

xxx x xx xx

,,xx I

. x , xxx x x

- x , x x

- x xxx x

x xx , a x

I sm ... :. x x

~ .

x 3 : x

=

I Z g

c xx x

I D m

s

=.

x x x

-x I .

=x xx I .

I .

1.....,

g _ g. i.- ,....r,....,....

D'cd AXIAL POSITION (NODES) l I

I I

33 I

l I

I NORTH ANNA UNIT 2 - CYCLE 4 Figure 4.13 l

1 I

l CORE AVERAGE AXIAL POWER DISTRIBUTION ;

N2-4-23 I '

I .

F = 1.158 I

. Z

A. O. = -4.10 1.2

IN

MM MNN NMEN I

EN EN IEXX

N X X N N XX XXXXXX

M N N EN M M E NN

M N N I M M s

I is3 .

g

~ .

M

] ,

IM I ]c :

=

_= ....

I N .

g .,M NI t ... .

' E :

5 -

I ;,.. . . . ;,. . . . ;,. . . . ,. . . . ,. . . . ;,. . .

.cf7DPI 0F cwt 1,. . . . ;,. . . . ;,. . . . ;,. . .;,....;.. ;

Ty W Cost AXIAL POSITION (NODES)

I I

I 34 I

I i

I J

Figure 4.14 NORTH ANNA UNIT 2 - CYCLE 4 CORE AVERAGE AXIAL POWER DISTRIBUTION N2-4-38 I

E ... .

Fg = 1.106

/. . o. - -0.57 a.a .

I .

=

M M

NNM NNNNN M NNNNN NNNMN MM NNMN NM NNNN NN

. M M N I

N N

. N N N N N MN N N

- ...; M S -

~ .

I N

. M M

E I .a

...i .N N m" :

I I

l ...;

,. . . . ;,. . . . g. . . . ,. . . . ,. . . ;,. . 1,. ..;,..........,.....,......* ".;" '

I AXIAL POSITION (NODES)

I I

I 35 I

Figuro 4.15 NORTH ANNA UNIT 2 - CYCLE 4 CORE AVERAGE RXIAL PEAKING FACTOR. F-Z VS. BURNUP I 1.4 I

I I 1.3 A

Ii A L

P E

A a '

K 1.2 ,

N

^

I G

e F 6 A a a A

A A 3

0 R

o 1.1 I

I I

I "~

0 2000 4000 6000 8000 10000 12000 14000 16000 CYCLE BURNUP tMWO/MTU1 36 I

r I

I Sectica 5 I PRIMARY COOLANT ACTIVITY FOLLOW I

I Activity levels of iodine-131 and 133 in the primary coolant are I~ important in core performance follow analysis because they are used as indicators of defective - fuel. Additionally, they are 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 2 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 2, Cycle 4 core. The demineralizer flow rate averaged 75.7 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. Specifically, the average dose equivalent I-131 concentration of 2.0 x 10 -2 pCi/gm is equal to 2*. of the Technical Specifications limit.

The step increase in coolant activity in July, 1985, was due to the recalibration of the germanium-lithium detector that is used to count the coolant samples. The change in the coolant activity measurements was not caured by fuel cladding defect formation.

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 g 3,

I I

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 leaving the I-131 dominant in activity, thereby causing the ratio to be 0.5 or more. In the case of large leaks and " tramp"* material, 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 2, Cycle 4 core at a general average value of 0.09.

The.se data indicate that there were probably no defects in the fuel used during Cycle 4, but tramp material remained from the previous cycle during which fuel defects were present.

I I

I . r - , _ si-s e f1ss1 - b1. - .r1a1 whi e aeher.s m e. - s14. -

the fuel.

38

I I

I NORTH ANNA UNIT 2 - CYCLE 4 Figure 5.1 DOSE EQUlVALENT l-131 vs. TIME TECHNICAL SPECIF ICATIONS LIMIT I :

I .

W e

I- s _

O

. O e g 2 e O sh **1pefAMe* e I a w

s, oe ac, s o

e g, e e o

u -$

o e's e e

O O O O e 0 I u-

~o r-

~

e fo 0"

I -

O e e o

- .100 r'

t j y l i- y 1 i N

I l .50 g

. . . . 2 o

I DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FES 1985 1986 39 I

Figure 5.2 NORTH ANNA UNIT 2 - CYCLE 4 1-131 / l-133 ACTIVITY RATIO vs. TIME s

I =

I ;

O I-sd I E e

>o

_~

I E a

I f S

\

O e -

To e e I

~

e Cl I e o e e

g a a 6 -

ec peps & i v(e pn 4M a N etwaveWM

.I a C

e _

F I- "

{ 1 1

~

-y '

==

l-l .so m lI l $ \ l ,0 5

I DEC JAN FEB bAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB 1985 1986 40

I Section 6 I CONCLUSIONS l

i I

The North !.nna 2, Cycle It core has completed operation. Throughout this cycle, all core performance indicators compared favorably with the design I, predictions a d the core related Technical Specifications limits were met with significant margin. No significant abnormalities in reactivity or burnup accumulation were detected. In addition, the mechanical integrity of the fuel has not changed significantly throughout Cycle 4 as indicated by the radioiodine analysis.

I

/

I I

lI 41

Section 7 I

REFERENCES

1) B. D. Mann, " North Anna Unit 2, Cycle 4 Startup Physics Test Report," VEP-NOS-14, November, 1984 I 2) North Anna Power Station Unit 2 Technical Specifications, Sections 3/4.1 and 3/4.2.

3) T. K. Ross, "NEWTOTE Code", VEPCO NFO-CCR-6 , Rev. 8, April, 1981.

I, 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.

II l

l I

I 42

_ _ _ _ _ _ _ _ _ _ _ _ _

ML20155F572

Contents

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

Navigation menu

ML20155F572

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

Navigation menu

Search