ML20059G088

Proposed Tech Specs Re Temporary Change to Section 3.3.3.2 to Reduce Required Number of Operable Incore Detector Thimbles to 50% for Remainder of Cycle 8

ML20059G088
Person / Time
Site:	Beaver Valley
Issue date:	09/04/1990
From:	DUQUESNE LIGHT CO.
To:
Shared Package
ML20059G085	List: ML20059G082 ML20059G086 ML20059G088
References
NUDOCS 9009120130
Download: ML20059G088 (28)

Text

._ -. _.... _ _. _ _ _ _. _ _ _ _ _ _ _ _.._ __ _ _ _ _____....__ _._. _

s i

l ATTACHMENT A a-

-4 Beaver Valley Power-Station, Unit No. 1

)

[-

• Proposed Technical Specification Char.ge No. 180:

J 4.

l Revise the Technical: Specifications as'follows:

o j.

L Remove Page Insert Pace l

.A 3/4 2-6 3/4 2-6 j

)

3/4 2-6a' I

i

'd 3/4 2-7 3/4~ 2-9 3/4 2-9 l

3/4 3-37.

3/4 3-37 B 3/4

'2-4' B 3/4-2-4

[

-i

)

r l

I l

i t

I

't

('

i i

?

I

- E i

i b

e t

9009120130 900904 i

PDR ADOCK 05000334 P

PDC

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

POWER DISTRIBUTION LIMITS SURVEILIANCE REQUIREMENTS 4.'2.2.1 The' provisions;of_ Specification ~'4.'0.4 are not applicable.

L 4.2.2.2

'F shall be evaluated to determine if t

iEElimitby:

F (Z) is within g

a. Using the.

movable incore detectors to obtain -a

. power h

distribution. map. at-THERMAL POWER.

anyLTHERMAL POWER. greater than 5% of. RATED j

b. Increasing; the measured F

component

.of the; power-distribution-map by 3%toaccoEntformanufacturingtolerances-x and-further.

increasing the value by_-54 to account-for..'

measurement uncertainties. <

{dSE47- [

l_

c. Comparing the F C

xy computed (Fxy ) obtained in b, above.to:

1. The F

limits for RATED THERMA.,

POWER (F K )

for-the x

R approprEate measured core planes-given.in e and YY below, and

2. The relationship:

F xh = FYy (1+PFXY(1-P))

P m

where F L

xy is.the limit for fractional THERMAL' POWER operation expressed as a function of F E, PFXY is the Fower Factor multiplier for'F provided.in the CORE xy OPERATING LIMITS-REPORT, and.P is the fraction of RATED THERMAL' POWER at'which F was mesasured.

xy

d. Remeasuring F according to the following schedule:

xy C

1. When F is greater than the'F' RTP limit 'for the xy xy appropriate measured core plane but less than.the F

~

L xy relationship, additional power distribution' maps shall be C

RTP L

taken and F compared,to F and F xy xy xy:

a) Either within-24 ' hours after POWER. or' greater, the THERMALLPOWER~at which-F THERMAL j

was last determined, or xy b) At least once per 31 EFPD, whichever occurs first.

% S< e page Mt' 3-37 kehde b /,4,%ha.

BEAVER VALLEY - UNIT 1

\\

3/4 2-6 000fGSE=b i

h

)

/

?

i INSERT A--

- e

- v When' the

r. umber. of available movable detector thimples is less than 75%*- of the tothl, the-5% measurement uncertainty shall be increased to 5% + [3 gT/12.5)) 2%, where T'is the number of available thimbles.-

- s 4

9 P

G

\\

I

[

4 F'

1 l.

e i

e 4

9 8

g e

5 0

0

.j..

POSER DISTRIBUTION LIMITS

- SURVEILIANCE REQUIREMENTS ' (continued)-

'2.

When the Fxy is les's-than,orequal'totheFyPlimit for

-the-appropriate measured' core, plane,. additional power D

distribution maps shall' be taken and F

compared-to c

F[y P

xy and F at least once per? 31L EFPD.:

xy J

e. The F

limit for ~ Rated Thermal-Power

- ( F "y xy x

) shal'1'be!

provided for all core planes containing bank "D" control rods' l

L

'and all unrodded core. planes.in 'the' CORE OPERATING LIMITS REPORT.-

{

i

f. The F

limits of ' e,

above, are n'ot spplicable. in the' '

5 xy following-core plane-regions 'as! measured from the bottom.of' the fuelt-5

1. Lower core region from 0 to 15%',' inclusive.

I

(

L

2. Upper core region from 85 toL100%, inclusive.

3. Grid plane region 12 %'

of' core height.

(12.88 inches) measured from grid centerline.'

4.

Core plane regions within,12% of core height (12.'08 inches)

}

i about the-bank demand position of the-bank "D": control.

rods.

}

c

g. With F

exceeding F

the effects-.o'f F

xy xy, xy; on F

-( Z )

k g

shall be evaluated to determine. if F

.(Z)l -is withincits-g limit.

q 4'2.2.3 When F

(Z) is measured pursuant-to Specification g

4.10,2.2, an overall measured Fg (Z). shall' be obtained from: a power i

distribution map and increased 'by 3%.to account for manufacturing' tolerances and further increased by 5% to account for measurement uncertainty. <

OffT D l

1

% See. fag e 3/'/ 3 'J*? -fwfno}e Sc/ /, kob/7ch,

'I 3/V 2-7 BEAVER-VALLEY - UNIT 1

-3'/4 2d.

-- 0 0: t p p 6 3/ ' L 3 ) --

f&903Eb

(

.' POWER O!STRJBUTION LIMITS-I

?-

SURVEILLANCE REQUIREMENTS N

4.2.3.1 F. shall ' be det nnined to 'be within~ its ;11mit 'oy using moveable.

' Nore detectors to.obtain' a power distribution map:

i ia.

Prior-to operation above 75% of RATED THERMAL 4 POWER tifter each

~

fuel loading, and l

L b.-

At least ~once per 31. Effective Full Power Days..

L

,4.2.2.2 The measured F of.' 4.2.3.1.above, shall be Vincreased by 4% for ~

measurement uncertainty.. Idkew -id(.MMcNer[: ads /4f/e movenh/c:

H less % -7p/;*o/ yliJJhr/, gla ni, ;

vielecJu Jhafles is pensureme.d u>,cdh.Uy nl&// Le i c'.% sed b

'I % + E2 - fr/a.r)) I%, wAen r ;g..k -, bes &

a ea,'la % th alles..

l i

i 1

1 1

1 ASe s pope.7/t' 3-37 Joc,fnole -fe ),klQg l

L BEAVER VALLEY - UNIT 1 3/42-9' i

fA0P03@

R

, INSTRUMENTAT M MDVABLE INCORE DETECTOM e

LIMITING CQMDITI N FOR OPERATION i

3.3.3.2 The movable:icore detector system shall be OPERABLE with: 1

_a.

A'tleast75dofihesetectorthimbles,1 I'

b.

A minimum of 2-detector thimbles:per core ~ quadrant',:and c.

. Sufficient-: movable detectors, drive, and readout equipment:

to map these' thimbles.

AEETJSMI112Y:

When.~the. movable-incore detection' system is:!used.for:

Recalibration of: the axial flux offset detection system,

-a.-

b..

Monitoring the QUADRANT POWER. TILT RATIO, or N

Neasurement of-Fg-and Fg(8).

c.

MTIQll with the movable incore detection system inoperable, do not use the system for the above. applicable monitoring or calibration functions.

The provisions of. Specification 3.0.3 are not npplicable.-

SURVEILLANCE REQUIREMENTS

-j 4.3.3.2 The incere-movable detection system shall be demonstrated b7 OPERABLE by normalising.each detector output to beLused within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to its use when required fort a.

Recalibration 'of the encore a:tial flux offset detection system, or b.

Monitoring the QUADRANT POWER TILT RATI9, or i

N' Measurement of Fg and Fg(E).,

c.

a 4-%e,b' 150.vtdu4cleA' O C cle T a. mo'n'O oE W Skt cle/ec/?

y ft, V, an re y Ac/ a/

d4 plo.peakip k&g wM A +saara/ unceola!4 apph W h m riege %p.eaq cla sita# exp k J shJdra k & g& nL G;y o?}aage, BEAVER VALLEY - UNIT 1 3/4 3-37 kCf0.5O 1

h

]

POWER DISTRIBUTION LIMITS -

J BASES

[

3/4.2.2-AND 3/4.2.3 MEAT FLUX AND NUCLEAR ENTHALPY MOT CMANNEL FACTORS-F '(Z) andFfH-g i

h The limits on heat-flux and nuclear enthalpy hotichannel' factors.

ensure that' 1) the design : limits on peak local power density and-minimum DNBR are not exceeded and 2): in the Jevent of a' LOCA the. peak '

fuel ' clad temperature will~ not. exceed;the ECCS acceptance. criteria'.

-limit of 2200'F.

.i h

Each of' these hot channel; factors,are measurable but

will, normally only be.

determined periodically as; specified-Specifications. 4.2.2 and 4.2.3..

' This ; periodic surveillance, in.

is t

sufficient' to

. insure that the hot' channel

.3ctor limits-are maintained provided:

a. Control rods in a.' single group. move together ;with.no individual rod insertion-differing by-more than 1 12Jsteps.

from the group demand position.

t

b. Control rod groups' are sequenced with overlapping groups as 1

.i described in Specification 3.1.3.5.

L

c. The control rod insertion limits of Specifications 3.1.3.4 and 3.1.3.5 are maintained.

7

d. The axial power' distribution, expressed:in terms of AXIAL FLUX DIFFERENCE is maintained within the limits..

N The relaxation in F

3H as! a function-;of THERMAL POWER. allows changes in tge radial power shape: for allipermissible rod insertion limits.

F 4H Will. be maintained--within its. limits-provided conditions'a thru d above,Jare maintained.

When a

Fg ? measurement is

taken, both' experimental error and manufacturing tolerance must be'allewed for.

5%-issthe appropriate i

experimental error allowance for a ifull;; core map taken with the incore detector flux mapping system and. 34 in-thei appropriate allowance for manufacturing? tolerance. dIWSbC7-9) l

}

The specified limit-of F$H ' contains - an. 6%: allowance-for uncertainties which.means hat normal,. full

power, three. loop, operation will result in F

less-than or equal to the design limitspecifiedin.theCOREOPENATINGLIMITS-REPORT.

4 See page. 3/V 3-37 fevhus}g fu /,ilfhi,,

BEAVER VALLEY - UNIT 1 B 3/4 2-4 MWGMb 1

I

ATTACHMENT B K

Beaver Valley Power Station, Unit No.- 1 Proposed Technical Specification Change No. 180 1

REVISION OF SPECIFICATION 3.3.3.2-1 REDUCED NUMBER OF INCORE THIMBLES

- i l

A.

DESCRIPTION OF AMENDMENT REQUEST The. proposed.: amendment-would incorporate a. temporary change to specification-3.3.3.2 to relax the--required number of incore detector thimbles from 38 to-25 (75% to 50%) for the remainder of j

i Cycle 8.

The 8th refueling outage is scheduled for: April 1991, j

during: which, the inoperable thimbles are expected to.be restored-to operable.

i B.

BACKGROUND.

l During the 7th refueling outage an eddy current. analysis was q

performed :on the incore detector. thimble tubes.and'as a resultlof tube thinning the-following eight.(8) thimbles were isolated:

Detector Drive B

C D

E Isolated J05 B10 EOS BOS 4

Thimbles LO4 F08' D12 H06 i

During the 6th-refueling outage thimble J15 (Detector C) was isolated due to thimble tube wall thinning and. thimble Fil (Detector C) was isolated due to a kink that~ prevents detector passage.

Thimble C08 (Detector.B) is not isolated,-.however, due

'l to blockage it cannot be used. for flux mapping.

Currently, thirty-nine (39) thimbles are available, however, should more l

than one thimble become inoperable, the minimum number of thimbles would not be met in 'accordance with' specification 3.3.3.2.

C.

JUSTIFICATION To compensate for the reduced number of thimbles, it is proposed to increase the uncertainty factors applied

.to. 'the peaking.

factors when a

flux map is performed with less than175% of the thimbles.

For Fq and-Fxy the flux map measurement uncertainty will be-increased above the 5%

normally applied by the relationship 5%' +

(3-(T/12.5)]

2%

where T

is the number of available thimbles.

This relationship- (see Table 1. attached) increases the uncertainty allowance to 7%

when half of the thimbles are used.

For F

delta H

the flux map measurement uncertainty will be increased above the 4%'normally applied by the relationship 4%

+

[3-(T/12.5)] 1%.

This relationship'(see Table 2

attached) increases-the uncertainty allowance to 5% when half of the thimbles are used.

These changes are similar to amendment No.

61 approved for the remainder;of Cycle 3 dated January 19, 1983.

As stated in the NRC safety evaluation ~for that amendment, relaxation of the 75%= requirement has been

TTAUMMENT Q

/ Technical Specification.180,. continued Page:2' permitted for the' duration of affected reactor operating cycles and' - the' appropriate allowances are similar to those made for other. reactors.-

l D.

SAFETY ANALYSIS l

The-ability to detect anomalous conditions in the core is a safety concern related to degradation of the incore; flux mapping system.

One of these concerns is-the inadvertent.oading of a fuel-assembly into an improper position, since.this is a loading

problem, it is not a concern for'the remainder of this operating cycle.

Other-anomalous conditions which could produce either axial: or radial effects would be identified as changeslin the quadrant" power: tilt ratio or axial offset ratio, however, these.

parameters.are monitored and_ would be detected'by..the excore 1

3 detectors.

Thet excore detectors and_ core exitithermocouples, provide information-that is_ available to supplement the'incore detectors and detect potentialiproblems.- Operation-of the plant for.the-remainder of cycle 8

will be safe with the number of_

~

incore thimble locations reduced to as few as'50% since adequate >

4 peaking factor margin exists and the increased-measurement uncertainty allowance provides additional assurance that peaking factor -limits will.be met.

In addition, the excoreLdetectors provide supplemental indication of core-conditions to preclude an unsafe condition from - being.undetectedLin the ab'ence of a full s

complement of incore thimbles.

Attachment 1

provides the results of various flux maps performed during cycle 8

and shows the margin available -between. the measured peaking-factors and the limits.

As shown in Table 1.and the

figures, adequate margin is available between the measured peaking factors and the limits.

Attachment 2

provides: the results of a nonuniform distribution evaluation which investigates the' loss; of' operable incore i

thimbles that-are not uniformly distributed throughout the core.

't Based on the flux maps examined in this evaluation the results are consistent with those seen.in the~ original study.

The. available peaking factor

margins, along.with the; proposed l

increases in measurement uncertainty, provide' conservative margin-i to the-limits.

Therefore, sufficient compensatory measures are L

available to preclude concerns-that monitoring of the. required parameters would fail to detect a problem for the remainder of.

this operating cycle.

t

-+

w--

n v

,(

i

[

~$ ATTACHMENT.B,

continued-j l

l

. Technical Specification'180, Page:3!

't The

• - footnote added.to specification'3.3.3.2Landireferenced'in L

the l applicable peaking factor surveillance requirements states i

that this' is' a temporary change and expires at the end of cycleL j,

8.

This-was defined as'such to-eliminate the'necessitycforLan:

j expedient technical specification

' change-to. remove these j

temporary changes at the end of the cycle.-

This will-not affect-the. safety of the plant even if:left in place during subsequent-cycles. since these changes will only apply during:the remainder

',i of Cycle' 8.-

Based on-the>above considerations, theseLchanges-reflect the application of-methodologies,which' provide a

l sufficient margin- -of ' safety, therefore, lthese changes fare 1

considered: to be safe 'and will not reduce the safety.of the plant.

1 4

i E.

-NO SIGNIFICANT HAZARDS EVALUATION.

The

.no significant hazard considerations. involved with:.the

]

proposed amendment have been. evaluated,: focusing on the;three-standards set forth in.10 CFR 50.92.(c) as quoted below:

i The-Commission may make a final determination, pursuant to the~

procedures in paragraph 50.91,.

that.a proposed-amendment to-an operating ' license for a facilityt licensed under paragraph 50.21 (b) or paragraph-50.22 or, for. a testing facility involves ru) significant hazards consideration, if operation-of the. facility in accordance with the proposed amendment wouldinot:'

(1)

Involve a

significant _ increase-in. the. probability or consequences of an' accident previously1 evaluated;'or (2)

Create the possibility _ of5ra-new or different kind of.

accident from any accident previously; evaluated; or (3)

Involve a significant reduction in a: margin of safoty.

The following evaluation is provided for the' no significant hazards consideration standards.

1.

Does the change involve a=significant increase in the-probability or consequences of an accident previously evaluatad't.

Q Specification 3.3.3.2 has been revised by adding a footnote.*

which allows relaxation of the required number of incore. detector i

thimbles

-from 75%

to 150%

for the. remainder of Cycle 8 ~.

Compensatory measures have been incorporated: to. increase the-uncertainty factors applied to the peaking fact rs when: a flux map is performed with less than '75% ~ of the t.4imbles. :These changes are similar to Amendment No.'61 that was-approvedLon a-temporary. basis for Cycle 3

operation.

Relaxation of'the 75%

requirement has been~ permitted for the durationlof other utility reactor operating cycles to allow continuedLplant operation with additional allowances similar to those proposed here.-

1

a T

ATTNCHMENT;Pc continued; L

4 Technical Specification 180,

'Page14

=)

~Available-peaking factor : margin Hto thei limits along with-the_ '

. proposed increases' in measurement; uncertainty provide sufficient q

compensatory measures. to

. preclude. concerns that-required D

monitoring of the limits would fail to' detect a problem for=the J

remainder of. Cycle 8..

A.' reduction in the number.

of-' operable incore flux thimbles introduces-a safety ~: concern-related: to1 detection'of anomalous'

];

conditions. in the. core, such as,-inadvertent;1oading of alfuel.

assembly into-an: improper position.-

However, this is a? loading; problem and~ is'not a concern for the remainder of'this. operating cycle.

Other anomalous conditions that'could' occur would produce either axial.cnr radial' effects and would'be' identified:in the-l quadrant power. tilt -ratio.

or..' axial coffset.Lratio: which are monitored by the~excore detectors.. 'The excore detectors and core exit thermocouples provide additional: sources of information toj i

supplement the incore detectors and~detectipotential problems.

operation of the plant for theLremainder?of'cyclel 8-will be safe with the-number 'of thimble. locations reduced to as few as-50%.

l l

since margin

-is available in 'the' existing; peaking) factor l

determination and the increased.measurementTuncertainty provides J

l additional assurance that peaking _ _factorf' limits.will~be met.-

~

l Supplemental-indicators of anomalous ' core - conditions are-also available to preclude unsafe operating 1 ' conditions; from being undetected in the absence. of. full'incore detector flux mapping capability.

Therefore,.the, probability of1 occurrence or the i

consequences of accidents previously. evaluated will.not-be increased.

2.

Does the change create the possibility-ofta;new or-different kind 3

of accident from any accident previously evaluated?

t The proposed change is.a: temporary amendment,Eto allow operation with a

reduced number' of incore detector thimbles.: Adequate' margin to the peaking factor limits isavailable and ithe uncertainty allowance is increased-toLensure the. peaking factor limits are met.

In

addition, other means are available,to i

determine core conditionsi related to. axial'and radial' effects which affect the quadrant power' tilt ratio orzaxial offset ratio.

monitored by the-excore detectors.

The core exit'thermocouples are also available to supplement the incore detectors in monitoring the condition of the core.

None of the accident analyses will be affected by.the proposed changes-and, based on the above, these changes will not create the possibility of'a new or different kind of accident from any accident'previously

. evaluated.

~,.

. - ~...

4

J.

^[,

I

. ATTACHMENT B

. Technical-Specification'180, continued

{

Page;5

'i 3.-

Does~ the' change ~. involve-a significantireductioncin a' margin of_

safety?

The proposed changes do not. affect any plant ~ set?' points, therefore, the safe operation:of the! plant will-not be-affected.:

-The:' increased' uncertainties applied.tolthe peaking factors when operating _ withfless thanL75% of the-detector. thimbles areEimpospd a ' compensatory measure to ' ensure' the peaking ' factors:

.' a s conservatively reflect-the core!. conditions.

Therefore,.even t

?

-though ~a-reduced' number of thimbles-are used, the core conditions'

'will be' adequately detected-without significantly: reducing the' margin of safety of the plant.

F.-

NO SIGNIFICANT HAZARDS-CONSIDERATION DETERMINATION Based on the :above safety-analysis,.it is concluded-thatsthe; q

activities associated.

with-this-licenset3 amendment; request t

satisfies-the no significant hazards consideration standards of 9

consideration finding is iustified.

~

no significant, hazards 0.92 (c)

and, accordingly, a

10 CFR 5

}

G.

ENVIRONMENTAL EVALUATION L

The proposed changes have't been evaluated ~!and it-has.been l

determined = that the changes do not involve' (i) a significant hazards consideration,

-(ii) a significant. change-in the types or significant increase in the-amounts of any effluents'that may:be; released

offsite, or (iii) a significant: increase in individual ~

or cumulative occupational radiation exposure. ;Accordingly, the proposed changes meet the: eligibility criterion for: categorical-exclusion set forth in 10 CFR 51.22 i (c) (9).: =Therefore, pursuant l

to 10 CFR 51.22 (b), an environmental assessment of~the proposed changes is not required.

]

L 1

i i

l ll' f-l

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

l

+

' TABLE.1

, HEAT FLUX HOT CHANNEL FACTOR j

1. of Thimbles' used.

Uncertainty without-With Tech Spec

]

Tech Soec revision Revision i

i 50-

'100%-

5%

5%

40 80%

~ 5%-

5%

35' 70%

N/A 5.4%

j q

1-30 60%

N/A.

G.2%

4 25 50%

N/A

- 7. 0%.

g 4

4 a

Measured Fq, Fxy componunt of.the power distribution' map

~

Measurement uncertainty increased:

5% +[3-(T/12.5)) 2% where T11s=the-

j

1. of thimbles used

?

r

.c l

l TABLE 2 i

NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR l

With Tech-Spec L

1. of-Thimbles used Uncertainty without.

Tech Snec revision Revision 50 100%

4%~

'4 % -

40 80%

4%

4%

.l 35 70%

N/A

'4.2%-

30 60%

N/A>

4.6%:

25 50%

N/A 5.0%

Measurement uncertainty increased:

4% + [3-(T/12.5)) 1% where T.is

'# of thimbles-used l

l l'

h

. - -... ~

_ -...~..

ATTACHMENT,1 Beaver Valley Power Station,. Unit No. 1 Proposed Technical: Specification Change No. 180 Cycle 8 Flux Man Evaluation-i l

~

-Attached is Table 1 which provides a summary of the peaking factors determined -for eight_. of the various full core flux maps that have been performed to-date during BV-1 Cycle'8 operation.

The attached figures-graphically present the-margin available to the-peaking L

factor limits after including the appropriate engineering and uncertainty factors.

. ould increase. the The proposed Technical Specification Change w

uncertainty penalty applied -to-the measured peaking factors.

This would tend to decrease the numerical value of the safety margin by up to two percent for Fq.and Fxy and up to one percent for F~ delta H.

As indicated on the

figures, sufficient-margin is available to incorporate the-added penalty.

In addition to the added uncertainties, _the trending of incore thermocouple exit temperatures collected during flux mapping will be used to-further: confirm the reliability of the core analysis results performed' when using a reduced number of thimbles.

i t

l L

L I

e

~

+

,v,

,-,4

TABLE l'

SUMMARY

OF FLUX MAP PEAKING FACTORS Fxy

'F' Delta H FQ-Flux Map.

Burnup Margin to Margin to'-

. Margin.to

.i Number (MWD /MTU)

Limit (%)

Limit (%)

. Limit (%)

i 9

370.8

'4.64 8.32-16.49 10 1425.9.

2.98 7.44-13.68 12 2327.5-3.70 7.30

~14.02 13 3219.1.

4.58 7.88

-16.03-14 4023.4 3.98 8.19 17.53 15 4989.1 5.08 8.87 22.19' 17 5950.7 4'.95 8.32 20.35 19 6625'.4-5.24.,

8.51

'19.70 i

l 1

.a

.i I

e.,,

+

m FIGURE 1: FQ(Z) MARGIN VS BURNUP (CYCLE 8)

FO(Z) MARGIN TO LIMIT (%)

30 20 10 0

0 1.000' 2.000;-3.000 4.000.: 5.000 6.000- -7.000:.8.000 9.000 10.000 11.000.-

' BURNUP '(MWD /MTU).

e

,=s.

• 'esw'

,s.aan y

an,

,,,Mr y

.%na'6(.

p wwe-af%

g-

,w

• V-

+"i e'

M--'W'-'- - "'T

'w

i'--ehv.

e+4ep' yig'

"'-@1--

F' 7g.(*

,.sPw=-

4

+

(w-,<e*'e6

FIGURE-2: F DELTA H LIMIT VS BURNUP (CYCLE 8)

F DELTA H (%)

30 20 10 0

O 1.000

'2.000 3.000: _4.000 5.000 6.000-7.000 8.000 - 9.000 10.000.11.000

- BURNUP- (MWD /MTU).

1

- - =

w

,~

• e~~

-r'~~.~

v e*

^-

v

<~ -

~w,

=

w 1 the core diagonal-from upper left to lower

right, almost all: of the inoperable thimbles are located above and to;the right of_the diagonal. 'This nonuniformity'.

was not addressed in the original evaluation, therefore,..this evaluation examines the effects of a

nonuniform loss of detector thimbles.

~

i METHODOLOGY Since all of the full power flux maps that have been run for Cycle 8 have at least 10 inoperable incore thimbles, it was determined that a cycle 7 flux map that had at least 48. thimbles. operable would be;used as a

reference to-investigate the effects-of-nonuniform;incore thimble loss.

Cycle 7 and Cycle 8 have the same fuel management 1and l

similar power distributions, therefore, it11s-reasonable to' evaluate a

Cycle 7

flux map and1 apply ~the results to Cycle'8.. Table 1 -

Summary of Thimble ~ Deletion Incore Maps shows-flux : map' 38 was run j

with 48 operable thimbles, then run-again with.the eleven inoperable 1

thimble locations.

This case resulted in-an increase in-the-t l

predicted Fq, F

delta H and Fxy by about:0.5% each, therefore, the effect of omitting the-existing _ eleven last:thimbleLlocations is known to be small and in the conservative direction.

To characterize the nonuniform distribution'Las ' completely. as

possible, flux map 38 was rerun a number offtimes, each with the known eleven lost thimble locations removed.. Additional cases were also run with additional thimble locations' removed to achieve 70%,

60%

and 50% of the thimbles remaining; _ At least.eight' flux maps were run at-each coverage

level, including both uniform ~1osses (spread over the entire core) and skewed losses-(spread.over.the-upper right diagonal half-core).

Resulta sults provided in Table 1 show that in virtually.every case, is an increase in the measured Fq, F. delta H and Fxy over the

.nce case with 48 operable thimble locations.

A single case at coverage shows a

reduction of 0.03%

in - Fq compared to the mce case value.

A single case at 60%

coverage 'shows a scion of 0.04%

in F

delta H ~ compared-to the reference case

.ou value.

A single case at 70% coverage shows a reduction of 0.86% in Fxy compared to the reference value.

I i

ATTACHMENT 2

=

Beaver Valley Power Station, Unit No. 1

?

Proposed Technical Specification Change No. 180 Nonuniform Distribution Evaluation Page 2 A-key parameterc in describing the possible variability in the flux map -results lis the average reaction rate error in the: instrumented fuel-assemblies.

The original BV-1 thimble deletion study.showed reaction rate errors of 1%

to 3%, with maximum values'over 5%~in t

l peripheral locations.

The maximum reaction rate error seen in the 27 i

flux maps examined for this study is 3.3%.-

Therefore, the~ flux' map results examined in this study are consistent with that seen in the original study.

Conclusion

-Based on the 27 flux maps exanined for-both uniform and nonuniform loss of' additional operable thimble locations, it has been shown-that-no additional penalty need lus applied since the measured. peaking

'I factors are either larger than the reference, value or: negligibly-smaller.

However, other combinations'could'be run which may show a nonconservative result, therefore, the appropriate action is to apply the previously determined uncertainties'for the remainder of-Cycle 8.

5 I

l l

l

1

,).

b i

a t

a'

'

• C g [

O.<..1 0. 0 0. m' e.. a. m.

- n...-.,.,.

. n.. c.o......

-(

.4

+6%0 M"M. mmMMNmMM-MnnMmMon'-

nmenNNmnNMNt g 2 4,.

I t a

t-

'[

..=..

-~.-e-e-

. eennee 0

-m meon..en-..-

n

~

w - O.

0 0 0..0..0..'

C. o.. N. O. N. 0 6. - Ne O. *..C.O.*..O.n.

= =,6 m

s,..-

i em

-O; a-0: 00000000 00 00000000 *O'00000000000 c.

$.i.

dd dd dd-

• '~

3.'

d

..e n,

n..~.0

.m-0,e n.

-.mmeo

.n-e-

't nee N-e m.

w e n-omen m conn w

c ' e ' e c c e

m.. e. -

e m. e,..

.. c.,. c. e. e., e. h..

J 3,..m. O. c.

c.

. c e. c. e cme comeeces' ccom m mee e

i e

e.i t e e e e i ia e e e s ia e-s ie e ie ee e -

e..

..c:

,mmOO-c0

-e macen.,e

.,menN,eo.....'Oo -E O.

. C. O. O. n... O.

. m. n. o. n. e. *. O.

- C. O.O......n.

.M.

e-o c

,--go a O 00000000

• 00000000 MM OOO-COOOOOO.-e

$7.

dd

.dd,'

[dd i.

• ~8--.--

,0...-e.

8.mm..e O

8 :'

8'.8. 8".8.8'.5.8". 8.5 E. 8. E. s* 8. ". E. E.

8. 5. 5. 5. $. 5. $. 8...

~

~

. 5 L

, g - o..

s. - - --------.

s m..

c.o..

,e,.-

.n8.m. seeg

.c

,m.s m

0.. 0.. g.- -.- o g g -

e.ngs.-n

.. c.. -

. M. e...

i x..

nno--no--S Mn-nonan

,e O

n.Mnen-nn...

6s

.- a O

. w

-a:

JJ Wd WJ-t 8

e r.

y J

t!

w8'.

8. 8 8.B.8.:.8.B.8.:.

58.88888.8 8.B.:.8.8.8.38838 J:

se a a swoorwao w.wzaczw zwo.zzwwwww

. m n

,I,.e w ? e - -

n e.me.-e-

-. n meS,e' e

,o

-O

.-m.,

,e e,e,8 2,.n..

m.,eR,

,8e.-2 1.

... m

=>

m,e,.. e no-

.x.

,w

,w l': J J adda *Jud JJJJJJJuI JJudadaddad l

o..

.c1-n28.3.e-en

~

1

. e..,o n

• n,o

. n

..n

-c O.,.

. e..

..e.e.t.e s.e,e,n e Set

-,en z.,

n.

. M.. m..

-. a 0 00000000 en

• O*-0000 e

• • 0-0

.... -8 n

m.

'a:

dd dd

-0000*

ad x.

o 8

5': 88. 8.B. 8. :. 8 58...

B8 8

8. 888.8-

.8.5.8888.3.8.838,.

8 m

.w.o.

.wzawzw-zwa...wwwww

. e 4e.-..so nee-..

-n

.m-

-m

- m.,8,.. - - ;

,- O,-

.-m e

e5.a

.EM222,EE e

,0 MR 0 e

M M M

l': J J JJJJJJJJ ued JJJJ uda;JJJJJJJ' I

- mS.S.en8.E.e. c, e n o. S. R.. E... e

-n a n S.,. 8. e S.. $. e mn..

-n-n, 6.

n. o. n..

.en O. O. - - n w

L e-a O 00000000

.e g-en

(

n *=0C0000

-mJ-CO-O*O*OCO 6.

b b

b 9

r

.e 8' :. 8. 8. 8. 8. 8. 8 8. 8. 8. 8 888. 8. 8 8. 8 8..

88888888888 w:..........

.w.....

......z...

7

.5-

<..R.,e. m..e o R O.

.8 28..non e.,

5 m

., c.memen,nc, E noe,..m.

}

e,c-,-.e.3.n.ne n--

..e e-a-ce e

cc u-c.

u-

.e.

........ ~. ~. ~.

1. m.

o -

C.

-.C.

.C.

y:

N RRRRRRRR ft ????????:f' 22222222RF2 l8' E

fis a

s s ssssssss

-E.

ssssssss

-E. sssssssss,m.s

-E.

.n

- ecceeeee 00000000 emencern-2.w.

Mc.

C.

O*

0-O nNNNnnnn O

N N n W W N N n Nto n O am am ac n-

, u wwws 8 -s8a8a esso ww%Ie a

e e u w xs

~3 a

e em ee R.

M m e sees e seemse MMMM MSMMM

=

MMMMMMMM MMMMMMMM I

/

.i.

=

=

,r*=_:~,

=

a

• e mv

_v

_u a @

0

,.O 3

,i e

.9 ll

_e O

a ll 0

_u ll1

\\

g nu 7

9*

e e g o @

@o gu *9 e n9 O*

of @

o*

1t O

e _u

=

C u

,~

t g

,5

,.O s 9

e l

uv

,i:

.

~

=- e a i *g;-

3 tlil. e-

=

w5g s

?n

<t 5'

=,O l I ? a g e e

o si os$S aO-i} t ias sa nm2 -

, 9 g ;,i g e !

,l!

ATTACHMENT C Beaver Valley Power Station, Unit No. 1 Proposed Technical Specification Change No. 180 v.

Pagest 3/4 2-6 3/4 2-7 3/4 2-9 3/4 3-37 B 3/4 2-4 f

i

POWER DISTRIBUTION QMITH

' SURVEILLANCE REQUIREMENTS 4.2.2.1 The provisiona of Specificatiot, t 3.4 are not applicable.

4.2.2.2 F

shall be evaluated to determine if F (Z) is within iEElimitby:

g a.

Using the movable incore detectors to obtain a

power distribution map at any THERMAL POWER greater than 54 of RATED THERMAL POWER.

b.

Increasin the measured F(5 account component of the power distriWt on map by 3%

for manufacturing tolerances and further increasing the value by 5% to account for measurement uncertainties.

When the number of available movable detector thimbles is'less than 75%* of the total, the 5%

measurement uncertainty shall be increased to 5%

+

[3-(T/12.5))

2%,

where T

is the number of available thimbles.

c.

Comparing the F

computed (Fxy )

obtained in b,

C above tot xy 1.

The F limits for RATED THERMAL POWER (FRTP)' for xy XY-the appropriate measured core planes given in a and f below, and 2.

The relationship F L FRTP (1+PFXY(1-P))

=

XY XY where F L

xy is the limit for fractional THERMAL POWER operation expressed as afunctionofFgP,PFXYisthe i

Power Factor multiplier for F

provided in the CORE xy OPERATING LIMITS REPORT, and P is the fraction of RATED THERMAL POW 6R at which F was measured, xy d.

Remeasureing F according to the following schedules xy 1.

When F C is greater than the FyP liF4it for the xy appropriate measured core plane butIr,ssthantheFy x

relationship, additional power distrfoution maps shall betakenandFxfcomparedtoFRTP L

y and /xy:

• See Page 3/4 3-37 Footnote for limitation.

l BEAVER VALLEY - UNIT 1 3/4 2-6 1

IhW1pt DISTRIBUTION LIMITS

' SURVEILLANCE REQUIREMENTS, continued a)

Either within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after excewding by 20% of RATED THERMAL POWER or greater, the THERMAL POWER at which F was last determined, or xy b)

At least once per 31 EFPD,;whichever occurs first.

2.

When the F [ is less than orequaltotheF[y' limit g

for the appropriate measuredi core

plane, additional power distribution' maps shall be taken and Fy x

compared to F[yTP L

and Fxy at least once per 31 EFPD.

e.

The F

limit for Rated ' Therard. ' Power -(Fj{$

shall be xy provided for all core planes containing bank "D" control rods and all unrodded core planes in the CORE OPERATING LIMITS REPORT.

f.

The F

limits of c,

above, are not applicable in the gy following core plane regions as measured-from the bottom of the fuels 1.

Lower core region from 0 to 15%, inclusive.

2.

Upper core region from 85 to 100%, inclusiva.

3.

Grid plane region 12% of core height (i2.88 inches) measured from grid centerline.

4.

Core plane regions within i2% of core height (i2.88 inches) about the bank demand position of the bank "D" contral rods.

g.

With Ff. exceeding F h, the x

x effects of F

on F

xy g

(2) shall be evaluated to determine if Fg (Z) is within its limit.

1 1

4 4.2.2.3 When Fn (Z) is measured pursuant to Specification 4.10.2.2, an ovePall measured Fg (2) shall be obtained from a power distribution map and increased by 3%

to account for manufacturing tolerances and further increased by 5%

to account for measurement uncertainty.

When the number of available movable detector thimbles is less than 75%* of the

total, the 5%

measurement uncertainty shall be increased to 5% + [3-(T/12.5))

2%,

where T

is the number of available thimbles.

• See page 3/4 3-37 footnote for limitation.;

l BEAVER VALLEY - UNIT 1 3/4 2-7

@ DISTRIBUTION LIMITS

'SURVEILIANCE REQUIRENENTS 4.2.3.1 F[

shall be determined to be within its limit by using moheableincoredetectorstoobtainapowerdistributionmapt a.

Prior to operation above 75%

of RATED THERMAL POWER after each fuel loading, and b.

At least.once per 31 Effective Full Power Days.

N 4.2.3.2 The -measured F

of 4.2.3.1

above, shall be increased by formeasurenk!t' uncertainty.

When the number of available 4%

moveable detector thimbles is less than 75%* of the total, the 4%

measurement uncertainty shall be increased to 4%

+3

-(T/12.5))

14, where T is the number of available thimbles.

1 k

l

- I

• See page 3/4 3-37 footnote for limitation.

l BEAVER VALLEY - UNIT 1 3/4 2-9

INSTRUMENTATION MOVARLE INCORE DETgcTORS LIMITING CONDITION FOR OPERATION 3.3.3.2 The movable incore detector system shall be OPERAB12 withs a.

At least 75%* of the detector thimbles, I

b.

A minimum of 2 detector thimbles per core quadrant, and c.

Sufficient movable detectors, drive, and readout equipment to map these thimbles.

APPLICABILITY:

When tha movable incore detection system is used fort Recalibration of the axial flux offset detection system, a.

b.

Monitoring the QUADRANT POWER TILT RATIO, or MeasurementofE[HandF(Z).

c.

g MII.QH1 With the movable incore detection system inoperable, do not use the system for the above applicable monitoring or calibration functions.

The provisions of Specification 3.0.3 are not applicable.

SURVEILIANCE REQUIREMENTS

,1 4.3.3.2 The incore movable detection system' shall be demonstrated OPERABLE by normalizing each detector output to be used within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to its use when required fort a.

Recalibration of the excore axial flux offset detection system, or b.

Monitoring the QUADRANT POWER TILT RATIO, or MeasurementofI[HandF(Z) c.

g During the remainder of Cycle 8 a minimum of 50% of-the detector thimbles are required along with the increased uncertainty allowance applied to peaking factors.

These temporary changes shall expire during plant shutdown for the 8th refueling outage.

BEAVER VALLEY - UNIT 1 3/4 3-37

f o

POWER DIRTRIBUTION LYMITS i

'BAGES j

i l

3/4.2.2 AND 3/R.2.3 HEAT FLUX AND NUCLFAR ENTHALPY HOT CRANNEL l

FACTORS-F (Z) AND FfH g

l

)

The limits on heat flux and nuclear enthalpy hot channel factors ensure that 1) the design limits on peak local power density and

^

minimum DNBR are not exceeded and 2) in the event of a LOCA the peak-fuel clad tesperature will not exceed the ECCS acceptance criteria l

limit of 2200 F.

l Each of these hot channel factors are measureable but will normally only be determined periodically as specified in Specifications 4.2.2 and 4.2.3.

This periodic surveillance is sufficient to insure that the hot channel factor limits are maintained provided:

a.

Control rods in a

single group move together with no individual rod insertion differing by more than il2 steps from the group demand position.

b.

Control rod groups are sequenced with overlapping grnups as l

decribed in Specification 3.1.3.5.

c.

The control rod insertion limits of Specifications 3.1.3.4 and 3.1.3.5 are maintained.

d.

The axial power distribution, expressed in terms of AXIAL FLUX DIFFERENCE is maintained within the limits.

The relaxation in FfH as a

function of THERMAL POWER allows changes in t ge radial power shape for all permissible rod insertion limits.

F will be maintained within its limits provided uH conditions a thru d above, are maintained.

When a

F measurement is

taken, both experimental error and g

manufacturing tolerance must be allowed for.

5% is the appropriate experimental error allowance for a full core map taken with the incore detector flux mapping system and 3% is the appropriate allowance for i

manufacturing tolerance.

When the number of available movable detector thimbles is less than 75%* of the total, the 5% measurement uncertainty shall be increased to 5% + (3-(T/12.5)) 2%, where T is the number of available thimbles.

FNH contains an 8%

allowance for The specified limit of uncertainties which means that

normal, full

power, three loop N

operation will result in F

less than or equal to the design gH_

limit specified in the CORE OPERTING LIMITS REPORT.

• See page 3/4 3-37 footnote for limitation.

I BEAVER VALLEY - UNIT 1 B 3/4 2-4

... ~.

-