ML20002A518

Forwards Addl Info Re Applicant Proposed Tech Specs Change 155,Suppl 1,re Incore Neutron Detector Thimbles at Facility Per 780316 Request.Analysis to Question 1 Will Be Submitted by 780515

ML20002A518
Person / Time
Site:	Yankee Rowe
Issue date:	04/06/1978
From:	Johnson W YANKEE ATOMIC ELECTRIC CO.
To:	Office of Nuclear Reactor Regulation
References
WYR-78-35, NUDOCS 8011170452
Download: ML20002A518 (18)

Text

f J,

t

()

Tchphoto 617 366-9011 rwx 7'0 3 9 0-C739 YANKEE ATOMIC ELECTRIC COMPANY ura 78-as 20 Turnotke Road Westborough, Mossochusetts 01581

" Nnne

.w April 6, 1978 i:.l I?;

.a United States Nuclear Regulatory Commission 7

Washington, D. C.

20555

- e.,

7 Attention: Office of Nuclear Reactor Regulation

(,l

Reference:

(a) License No. DPR-3 (Docket No. 50-29)

{

N (b) Proposed Change No. 155, Supplement No. 1, dated December 14, 1977, WYR 77-127 (c) NRC letter to YAEC dated March 16, 1978 k'

Dear Sir:

A W,6 \\bb

Subject:

Additional Information Incore Detecto Systein Technical Specification Changes The additional information requested in Reference (c) is provided in Attachment I.

The questions are answered in the same order in which they were asked.

The analysis in response to the first question has not been completed, but will be cubmitted on or before May 15, 1978.

Any further questions regarding the enclosure should be directed to Mr. Richard J. Cacciapouti at our Engineering Office, 20 Turnpike Road, Westborough, Massachusetts, 01581, (617) 366-9011, Extension 2807.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY 99 W. P Johnson Vice President COMMONWEALTH OF MASSACHUSETTS)

)ss.

COUPTY OF WORCESTER

)

Then personally appeared before me, W. P. Johnson, who being duly sworn did state that he is Vice President of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing request in the name and on the behalf of Yankee Atomic Electric Company and that the state-nents thercin are true to the best of his knowledge and belief.

\\

Y[

f Y AA+---

S 13 0 1 1 1 Robert H. Groce Notary Public

< i v. w.

My Com=ission Expires September 14, 1984 6 u.

[

(m_)

[_')

ATTACEMENT I Additional Infor=ation Concerning Proposed Rede-tion of Incore Neutron Detector Th1=bles i.i Yankee Rowe A-1.

A study to demonstrate the ability to detector fuel misloading during stat tup tests with the reduced co pliment of incore detector thinbles is in progress.

Results of this analysis will be submitted by Mar 15, 1978.

A-2.

To verify t!<

nicum of twelve neutron detector thimbles would be capable <

ing a cenninC ul power distribution, a number of f

cases were i the 15 CORE program. The base case was the flux cap produce-oxiestely 2800 MED/MTU. Using all 17 available thi=bles, a of power distributions were also produced for a reduced corp.

..c of thitbles. All but 12 thimbles uere discarded in a random fashion with the only restricticn being that each quadrant contain at least two operabic thimbles.

The Yankee IECORE analysis procedure requires that the linear heat generation rate (LEGR) for the hottest fuel pins in each assembly be obtained from INCORE. Table 1 presents the taximum LPGR for the six hottest rods in the INCORE analysis both for the base case (17 thitbles) and for the cases with the reduced number of thi=bles (12 thimbles). This analysis showed that in cost instances, the reduced nudber of thinbles produced a higher ceasured LEGR.

Since peak LEGR increased over the base case, it is concluded that it would not be necessary to place an additional uncertainty on the tensured peak LEGR for Yankee Rowe with a reduced co:plicent of thimbles.

This conclusion is further substantiated by a conparison of the censured and calculated (PDQ) reaction rates. For the base case and the ten cases uith a reduced number of thir.bles, the reasured and calculated reaction rates verc cc: pared.

The co parison for all cases is shown in Figures 1 through 11.

The results,show that on the aversge, the difference between reasured and calculated reaction rates is relatively stable. Thus, it appears that a reduced corp 11-cent of thi=bles does not have a tarhed effect on the INCORE synthesis procedure. This can also be seen by a cocparison of the full core assembly powers and pin powers shown in Figures 12 and 13.

A-3.

It is Yankee's plan to =onitor core tilt by means of the tilt algorithm in the ITCORE conputer program.

From the cases run for 2 above, the core tilt as calculated by T".. CORE was compared for all cases. As Table 2 shows, the quadrant tilt is not adversely affected by a reduction in the nu ber of thiebics from 17 to 12.

Thus, the use of the INCORE tilt algerithm to monitor core tilt still appears to be a rea.onable ap;aars to be a reasonable appreach.

The following is in response to the other portions of question 3.

a.

Yankee believes that core tilt can bc monitored by reans of loop flows; however, to decenstrate the validity of this approach would require sore type of testing and calculational analysis. This testing and analysis has not been done and is 1

not planned fer the future.

l l

[,

e o)

G Q

=

b.

k'ith the current ccep11:ent of thichles, there is cnly one set of quadrant sy==etric thinbles. To require this one set to remain operable is unreasonable and defeats the intent of the proposed Technical Specification change. As was shown from the analyses perforced, quadrant tilt can effectively be conitored with a reduced number of thitbles.

A-4.

Based on the result of the studies performed, the Technical Specificaticn changes presented in Proposed Change No. 155, Supplement No. 1 are still valid.

e e

e

-t

s TABLE 1 IIAXIt1UM LINEAR llEAT GENERATION RATE COMPARISON BETWEEN 17 AND 12 AVAILABLE THIMBLES

~

ASSEf1BLY CONTAINo PIN WITu MaxiMun LHGR

% DIFFERENCE CASE C-3 D-9 B-7 C-3 H-8 B ll MAX. U1GR 3ASE+

10.303*

10.211 10.129 10.086 10.022 9.999 CASE 1 10.170*

10.083 10.046 10.108 10.045 10.021

-1.29 CASE 2 10.163*

10.073 10.147 10.103 10.040 10.016

-1.36 CASE 3 10.538*

10.447 10.163 10.083 10.019 9.996

+2.28 CASE 4 10.513*

10.410 10.244 10.163 10.099 10.075

+2.04 CASE S 10.370 10.269 10.352' 10.198 10.041 10.479*

+1.71 CASE 6 10.544*

10.454 10.170 10.089 10.006 10.002

+2.34 CASE 7 10.486*

10.395 10.113 10.206 10.001 10.118

+1.78 CASE 3 10.291 10.199 10.117 10.248 10.041 10.531*

+2.21 CASE 9 10.374*

10.273 10.109 10.029 10.244 9.942 40.69 CASE 10 10.358*

10.265 10.183 10.139 10.124 10.052

+0.53

• lbximum value

+ Base contains 17 thimbles all other cases contain 12. thimbles

a r.y.. =

~

f.,;

o.

0 Table 2 Comparison of. Relative Quadrant Tilt Between-17 and 12 Available Thimbles t

-Case Quadrant 1 Quadrant 2 Base

• 1.0018

.9886 1

.9997

.9907 2

.9991

.9901 3

.9971

.9881 4

.9995

.9912 5

1.0051

.9843 6

1.0023

.9876 7

1.0062

.9839 8

1.0074

.9830 9

.9965

.9785 10.

1.0038

.9866 Quadrant 3 Quadrant 4

^

Base 1.0071 1.0024 1

1.0066 1.0030 2

1.0079 1.0028 3

1.0140 1.0008 4

1.0085 1.0009 5

1.0097 1.0009 6

1.0130

.9971-

-- 7 1.0094 1.0006

.8 1.0073 1.0022 s

9 1.0046 1.0204 10 1.0102

.9994 i

• Base contains.17 thimblesi all other cases centain 12 thimbles

m(;..

Elgure 1 _

Cockarison of Maasured and Calculated Reaction Rates BASu CAEE v

A B

.C D

E F

G H

J K

Measured Reaction T. ate

.710 Calculated Reaction Rate 1

.731-Percent Difference

-2.92 1.009 5

2

-3.85 1.094

~

l5 3

-1.88 1:107 1.092 1.115 1.068 4

.es--

2.28

.745 1.098 1.052 5

.733

1. 71 1.063 1.56 2.52~

.96 l

1.101 1.071 b

2.82 1.068 1.102 1.103 1.070 1.068 1.115

. 7

. 12 3.23

-1.07, 1.099 l.113 1.115 1.111 n0

.16

-1.09

.733 1.039

.724 1.050 9'

i.14

-1.07 1

I

.734 O

.731

.41 4

!.varm;c Aikoltic Percent.- Dif ference = 1.63 r

m-

r:

-v

~

Cr O

Figure 2 Comparison of Measured and Calculated Reaction itates Case 1

-A B

C D

E-F G.

H-J K

Mecsured Reaction Rate Calculated Rasction Rate y

- Percent Difference

.931 2

.968

-3.85 1.009-1.028 3

-1.88 1.021 1.007-4 1.028

.985

.68 2.28 1.013

.971 98 5

2.52

.96 1.016

.988 G'

2.82' I

1.016 1.017

.985 1.028 7

3.23

-1.07 1.027 1.014 1.028 1.025 o

.162

-1.09

.958 g-

.968 -

-1.07 0

' i f feren c = 1.80 Avera;;e abse]ute retecnt J

r f

Figure 3 Cod.parison of Measured and Calculated Reaction Rates Case'2 A

B; C-D E-F

.G.

H J

K Measured Reaction Rate Calculated Reaction Race 1

Percent -Dif ference

.929 2

.967

-3.92 1.007 1.027 3.

-1.95 1.019 1.005 l}

.75' 2.20.

1.027

.983 1.010

.968

.986

.979 a

5 l

2.44

-1.03 1

1.013 986

-6 t

2.74

.983 1.014 1.015 7.

.s85

.983 1.027

' 20 3.16

-1.14 i

1.024-1.012 1.027 1.023 8

.24

-1.16 9-

-10 1

Avera-c Absolute Percent Di f fe rence = - 1 ~. 74..

1

t.

~~

o o

q_

Figure 4 Cor. paria,on of "easured and Calculated Reaction Rates Case 3 A

B C

D E

F G

H-J K

1 Measured Reaction Rate Calculated Reaction Rate y.

Percent Difference 1

.957 997 2-

-4.00 1.037

~

3.

1.059'

-2.03 1.050 1.035 1.059 1.014 g! '

.83 2.12 1.041

.998

.5 1.017 1.009 2.36

-1.11 1

1.044 1.017 6

2.66 l ~

1.013 1.045 1.046

1. 016 ~

1.014 1.059-

'y

. 28 3.07

-1.22 1.042 1.055'

.8

-1.24

.694' 1

.-688 9.

.98 i

.10 i

Avera;;c Absolute 1*creent Difference = 1.83

Cor:parison of Measure E"dCalculatedReactionRates Case 4 1

i A

B C

D E

F

, G' H

J K

.741 Measured Reaction Rate.

1

.756 Calculated- ?.eaction Rate

-1.95 Percent-Difference 1.054 1.085 2

-2.89 l.142 1.153 3

.90 1.156 1.153 N.

.31 4

.778 1.099 5.

.758 1,099 2.57

.03 4

6

\\

1.116 1.152 1.106 1.153 y

.. 87

.08 1.148 1.149

-g

.11' i

.765 1.084

.74 9 1.085 9-2'.14

.09

.766

_0

.767

.1 1.'41 -

-4 Average Absolute ' Percent Dlf ference = 1.11 '-

.y

/

Figure'6 Co::parison of Measured and Calculated Reaction Rates Case 5 A

B C

D E-F G

H J

K-

.741' Measured Reaction Rate 1

.765 Calculated Reaction Rate

-3.13 Percent Difference t

1.054 1.098 2

-4.06 3

1.136 i

1.117

-4:

1.74

.7.75 1.144 1.095 5

767 1.120 1.112 1.02 2.14

-1.48 1.149 1.120 6-2.60 1.150 1.117 7

3.01 1.147 o

1.163 0

-1.30

.762 1.081

.758 1.098 g

.61

-1.59 l

.764

.t0

.765

.'12 i

Average Absolute Percent Dif ference = 1,90

..=

O' O

Figure 7 Comparison of Measured and Calculated Reaction Rates Case 6.

A B'

C D

E F

G H

J K

.737 Measured Reaction Rate 1

.757-Calculated Reaction Rcte

-2.58 Percent Difference 1.049 2

1.087

-3.52 1.137 1.155 3

-1.54 1.151 1.135

((

'1.153 1.106

.34 2.63

.774 1~.141 1.094 5

.760 1.109 1.101 1.91 2.87

- 62 6

1.110 1.147 1.108 1.155 7

. 22

.73 w

.761

.750 9

1.48

.763 10

.757

.76 A ec rage ' Absolute- ?creer.t Differenec = 1.60

p

_p}

G, l

..~.

Figure 8 Cocparison of Measured and Calculated Reaction Rates Case 7

^

A B-C-

D E

F G

H J

K

.716 Measured Reaction Rate

.736 Calculated Reaction Kate 1

-2.69 Percent Difference 1.019 2

1.057

-3.62 1.104 1.123 3

-1.65

'4 1.106 1.059 1.078 1.070 s

5 2.60

-1.03

\\

1.111 1.078 g

3.06 1.075 1.112 1.113 7

1.077 1.075 1.123

.20 3.48

.84 1.109 1.119 o

.86

.737

.729 9'

1.06 J

.738

-3

.736

.34

\\

+

.Worane > Absalute Pcrecnt Dif ference 1.78 i

y o

o Figure 9 Comp,arison of Measured and Calculated Reaction Rates

~ Case 8 4

~

A B

C D

E F

G H

J K

Measured Reaction Rate Calculated Reaction Rate 3

Percent Difference 1.020 1.059 2

-3.63 3

i l{

.750 1.108 1.060

.740 1.080 1.072

'5 2.59

-1.04 1.47 i

6 1.076 1.114 1.115 s,.

1.079 1.077 1.124 7

.21 3.46

.85 1.122 1.111 1.'124 1.121 8

.25

.87

]

.738 1.046

.730 1.059

'g.

1.'05

-1.16

.739 d0 737

.33 1.41

. Average' Absolute ?creent Dif ference =

~

l U

U 1 Figure 10 Corparison of. Measured and Calculated Reaction Retes case 9 i

AL B

CL D

E F

'G H

J K-Measured Reaction Rate

.738 Calculated Reaction Race

.761-

}

-2.96 Percent Difference 1.051' 1.093 2

-3.90 1

1.139 1.161' 3

-1.93

.1.153.-

1.136 L

1.161 1.112

'l'

.73 2.23 1

.775

'l' 1.143

.764 1.115 D

1.51 2.47 6

1.112 l

1.147

.?

1.114 1.112

.' 17 3.18 7<

.l 8

.762 1.061

.754 1.093 '

1.09

-1.12 g-

.764 10

.761

.36~

.Averar,e.h.elute P ecent Diif.rence-= 1.80

,s -

~

('J.

C)

)-

v.

u.

Figure ' 11 Co:::parison of IIcasured.ano Calcdlated Reaction Rates

, Case 10 A

B C

D E-F

.G H

J K

.737 Measured Reaction R :a 1

.755 Calculated Reaction 7.are

-2.35 Percent Difference 1.049 1.085 2-

-3.29 I

1.137 1.152 3

-1.31

! 1.151 1.152 4

.10

.774 1.141

.758 1.106 5

2.15 3.11 6

~'

1.110 1.105 7

.46 1.157 1.142 1.152-1.148 8

.42

.51 1

.761 1.079

.748 1.085 b.-

1.72

.50 a

.763

.LO

.755 3

1.00 Average Abcalete Percent Dif fe rcnce = 1.41

aa.

,e 1 Figure 12:

Relative Assembly and Maximum Pin Power Base Case 6

A:

.B-CL D

E F-G H

J K

Relative Asse=bly' Power

.603

.-762

.762

.600 y

Fxy, Ibx. Pin / Core Power 1.264 1.294 1.300 1.269 2

782 1.116-1.074 1.082 1.122

.774 1.517 1.580 1.506 1.497 1.557 1.494

.783 1.213 1.181 1.086 1.067 1.153 1.198

.772 3

1.521 1.599 1.568

'1.243 1.236 1.523 1.572 1.499

.634 1.157 1.173 1.090 1.151 1.139 1.059 1.156 1.138

.615 4

1 322 1.585 1.561 1.294 1.~ 519 1.475 1.269 1.537 1.569 1.290

.801 1.130 1.094 1.157' 1.059 1.060 1.136 1.081 1.101

.773 5

1.357 1.560 1.268 1.514 1.279 1.275 1.488 1.'267 1.527 1.323

.793 1.117 11.100 1.154 1.063 1.065 1.157 1.087 1.111

.781

.342 1;547 1.277.

1.505 1.280 1.289 1.507 1;.266 1.545 1.329

. 6

. 6' 0' 1.148 1.170 1.073 1.154 1.157

-1.085-1.169 1.143

.'617 2

7 1.306 1.589.

1.554 1.282 1.501 1.511 1.285 1.555 1.579 1.296 2

.790 1.225 1.176 1.088 1.093 1.163 1.208

.780 I8 1.530 1.613 1.551 1.258.

1.269 1.555 1.593 1.515

.797 1.155 1.113 1.106 1.144

.778

~

g 1.537

1.599 1.537 1.541 1.574 1.511 4

.624

.786

.788

.623 10 1.308 1.336' 1.333 1.302

-: ~ ~.

-f.

}'

~

~'

s'

,em k,

Figure 13 Relative Assembly and Maximus Pin Power Case 1 A

B

-C D

E F

G H

J K

Relative'Asse=bly Power

.598

.757

.760

.601 y

Fxy, Max.. Pin / Core Power 1.255.

1.287 1.302 1.270

.783 1.108 1.071 1.084 1.125

. 776 2

1.521 1.584 1.511 1.499 1.561 1.498

.785 1.215 1.J84 -

1.088 1.069' 1.155 1.201

.774 3

1.525 1.603 1.572

.1.248 1.239 1.526 1.575 1.502

.621 1.150 1.176 1.092 1.154 1.142 1.061.

1.159 1.141

.616 4

1.304 1.589 1.565 1.297 1.522 1.478 1.272 1.541 1.572; 1.293-

.7S5 1.117 1.097 1.160 1.061 1.062 1.138-1.083 1.103

.780 5-

~.564 1.271 1.517 1.282 1.278 1.491 1.270 1.330 1.326 1.338 1

.782 1.106 1.117 1.156 1.066 1.067 1.160 1.039 1.113

.782 g

1.330 1.535 1.284 1.515 1.283 1.291 1.510 1.268 1.548 1.332

.621 1.150 1.172 1.076 1.156 1.159 1.0S8 1.171 1.145

.619 7

1.303 1.592 1.564 1.290 1.505 1.514 1.28S 1.558 1.583 1.299

.737 1.222 1.177 1.090 1.096 1.166 1.211.

.732 n0 1.529 1.607 1.554 1.261 1.271 1.559.

-1.596 1.519

.789 1.151 1.114 1/102 1.139

.780 9

1.529 1.593 1.537 1.542 1.577 1.515

-l 1

1 10'

.619

.782.

.779

.615 l'~ 303 1.335 1.324 1.291-

.