ML20059H490

Proposed Tech Spec 3.1.3.2 & Associated Bases Re Digital Rod Position Indication

ML20059H490
Person / Time
Site:	Callaway
Issue date:	09/07/1990
From:	UNION ELECTRIC CO.
To:
Shared Package
ML20059H488	List: ML20059H483 ML20059H490
References
ULNRC-2282, NUDOCS 9009180011
Download: ML20059H490 (14)

Text

g4 Mp?:

._ m _.m w% 4 " w, $ T E l M ~ Q. ~ _--

_,,%,_f% M7_DQ,,M ML

_m

.-y..m_my-QQ'FY,d_W, l #$M MMN

. <+,

g hwm a

a y'Vw &,w n m nty m + m: w&p/ m am **

w w

wx+>

-n

.,. s.

ns w

wm n

+

xva s +q. O a mm,n wu,w.ny v um n.w a

q r, )

w ew pM ;;p m;wm &,.=m wy pn;p v> r, %...

ana nr.

-, n 7a-4, = x n

y~. t ;n.:

v m;yg, r e,..m

, w o me,,.

s n n

c

.< frgo et q q M,=

or.

t

+

e

..u.

e [_

g,<

q, w

<m

~ys k.

0-

~

l < l.

'a a

, ~

-. - -l gr' y

~.

?

u m x

.a.+ <, % :..

~? ' # 1%

est

+

4%

F 4

y MmL '

4?

ynU.o-

..* i.,

f,..

t 4

p, s

. ui s

.i 6

su

., s

w.,

w, - -

a.-.

y a,#

>a cp1 g.

v n

o 3

m w.

er.

x.

a.

t n,

1. y a t

+

u.,, 4.1

, m.

s-v

..4

.,s.

n m-w - r, y s.

i s

m

.,?.

-7'a rNSU :.

"t ;g?5 i

g 1

4

e.

i 1

i tg i

i i -

A j. {,

t r

(a y

s y

,e %.,j,

,/

n3 1

g,

->r

-s t

~

N0*.

L y.

3m o p--'

e

\\

1 pi

' g_

.e 4 '

_g.

n y

\\y

.'d_

,v q)aqm

, pj t

.: f -' i -

E t

,;f a

,I' l

1,. k k k. ' :

2

,, w w",

( ' 3' k i T

p 1

h, f

f

, i '. :

r v

r

.o

+..

s s

m-g

,. /'. '

1 t

9 S 4 y

t p- '

-. y-p;5

,,;4 p

..y',

,r,,u, J0 o i

r---

4 5

i

.y.

1 -,,

1 c

gl 9 t

3 w

j;o. '

~

~-.

s 4 o,

m: e n*

"f igt--

..]

p -$

4 g

's a

3

..- 9, ?,

.,3j-..

• t' 1U

,j 6

4

4. P i.

e '

,f-

- )

y

..c_

b

~,

p.

n p-- ',

1(

g3 G

, _ i g

,,3

- d 1

4 kg j

- 6( a,5

.#., crn,

4 n,:

e r

e

>1: n, s

- m

s

,n,

-,r

.-e

+

c e,,

7 4

,a.

t g

g jr ?

4 -j-x

+<-

is e-J:4y 4

i u

3 7

s, a.

m,

+

o g,-

u.

s

.;g

.e.

e

..1

l s.q'

,.s

,m1 a

3 m..

s w

7 d'. [ ("# 1...f h.

f 4

>f

'!V. 4,. c a

1'

+-

(

Ji l

\\.

_.k._.

's i

ri

, i ;f_i h.

l h...

. la *)

-i

- i

,,~

w~

u' h 4:: s y

r.

ur

,y.*

n. -

,; e -

<e

.c v.

'ULHRC-SSS2 W -

. T1 gu, m.

. o.

m m,.

sv 4,

z,,p;,,

4

y..

w

, n,m; x

,8 t

3 p

p.m w,m

. s.;

1 1

. =

c n, -

. -.M ACHNENTl 6 pe, o w-ys, c d w.cdE >J V

e, z

o, fm q+,

> ; r. 3,. - -

st.4 d is s

e a+

u):

g,. g

~ TECHNICAL 1 SPECIFICATION: CHANGES:,, "' ~ W..

y.

a.

ra.,.

m,-.

1n

u..au e

<.j>

a

-4, f-h., g,3

,r

,a i

ia,-

3

.m.=

c

,a

--..:4 1

e-7 32, c

4.,

c W

m g,

w m

. N., ' m@ g v'.

i

1. f',

. ]..' T,-

m :.6:

y.

2 i

g

,.n n

4 p

r.

e, s-s n

~s m. ~

c

.,x

y y cy 4m o.-

4

.i.3

.na 3*

.c t

c

'<h-i

.* j... <

L - - g-)s

.g' q w: ' Q, ? ! ;-l, ' ' t

...e

-' j, s )g.

=

c-i r

_L I.e

n. q

-- 5 7 g f.

,) g n

a 3

3 t

6 3, {.,,.

s i

i ei 7

()

s'

_..t g' 3 y

) p_ y 7

,o

- p-

.s

,33 f 'eT 4

1

'-g

~

-l-A T#"'f J

,-s, t'

1 g% g-

_...t.

,f

.l-

~)

p9 t

m

-. i~

1

,4, i' )

g

=

g

.gi

,9p I

--' t i

'If gN /

7E j.

s s

_e m;,

1

~_

l r

33

+

9 io1..

o-

y

. g

,. -. ;p.,

+

r..-

m w,c i

y t

Mg.

s" ;.:

(

,I

~

j y

/ i 5

7..

m. m.

+ 4n.

1 4

,er g

r e

3

,1 gt i+

=ty

- g,

, e 1,

m

'l',

y ' g.

,9 3.

p. r : i -

-l g

? O.

4 s

w t

'l

• O

.O 1

I-J

-9 js v4 pg 43

-)

)

j f

., J g,.

q 9.h 3

..{

t#

/

7 r,

s i

I 1:{ T 56, i., 7 1

1. - t h

n z

j i

n s<#

. a

+

'l d ( j,

)

I,e-..

-*,Y k

,-s

) h. +.

n 1

2 1

2 j z..

Y'

(

'. S t

4

.w a

7b :m:

t.

~

- l,l 4

gj P

g..- tr At ym 5

.. qs

,J-

, _p..j g:

<.tv e

n m ;.,

m.,.

u r

gg8-'

I

]A-)

i=

4 1

4 k

[ 9 '.

j

,.? u 2 a.:i,

T, s

1

??

,h$ f.,.

Y, L

1 _

UR

)

. L ';. [

i x

, m.

m il f

/k k

m in) xy

~,

m.

, w+3 uy.

e" m,

y m

e e m ag y,.

a.

u g g.h y 11 -)

2..,

• ,h*'

+

t 6

i-g+.,; wq:

q

,.,1 v t

e uh

% '- [

[rjw h

w v e'

-ff>

s 4

r

+

lc nu a

1 m,g:

m+ - - -m, -

b s

m._ q -

y; s

^y.

w

..r3 1-4'<

rg 3 q'

-qe Uk 3

,r i',/

nfu

, { t?I

--i 5

T' II :.

t 6

.' k (_'

'O

(,i ?

.i 'i^

n !

NWu ?g

'"S a.*. '

JN Wg g

jam

>9

',a 90'09180011 900907-s -

- ADOCK05000483][L-

@Jn g m

PDR i

n. M,' v..

M W" n' '

4 P

..Q Q. Mj7:@ N;W ng:

PDC

~

$DN MM. * -

s.

m f:a@q' 7M_12M_D5[ $,. VN ' ?_ s. b.2m[# MbN M.N

,s, 1 [N

- u.

et s w, '... N did yy9.n./,N w>N

,~. w, v t 5

+

r 1

, r 3..f.u. a y j. M-S n,ty....

w d v,an-w, f.;.f,.w.a,.q.} i, - $ _, r y.u_,,.u.--,,.

.c 4

.q-

~

Tu w wL...._,0 @< W r _t n f.

y

<v4 s

r., y5...

..,,.ss a

-.u n a w. x, w.

w

,ms

.. ~.

..n

i S CN 2

RtACflVITY COP.1ROL SYSTEMS PO$l110N IN0tCA110N SYSTEMS-OPERAi!NG LINITING CONDITION FOR OPERAtl0N 3.1. 3. 2 The Digital Rod Position Indication System and th:, Demand Position Indication System shall be OPERABLE and capable of de%rmining the control

(

rod positions within i 12 steps.

j

4PPLICA81LITY

@ DES 1 end 2.

.A.1_110N:

l a.

With a maximen of one' digital rod position indicator per tonk inoperabte either:

j 1.

Determine the position of the nonindicating rud(s) indirectly by the movable incore detectors at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.and tamediately after any motion of the nonindicating rod which exceeds 24 steps in one direction since the last determination of the ron's position, or 2.

Reduce THERMAL POWER to less than 505 of RATED THERMAL POWER within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, j

be

.ZNTERT /

d,Apr With a maximum of one demand position indicator per bank inoperable 7,

either:

i 1.

Verify that all digital rod pcsition indicators for the affected bank are OPERA 8LE and that tha most withdrawn rod and the least withdrawn rod of the bank are within a maximum of 12 steps of each other at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or i

1 2,

Reduce THERMAL POWER to less than 50% of RATED THERMAL POWER within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

SURVE!LLANCE REQUIREMENTS l

4.1.3.2 Each digital rod position indicator shall be determined to ba OPERABLE by verifying that the Demand Position Indication System and the Digital Rod Position Indication System agree within 12 steps at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> except during time intervals when the rod position deviation' monitor is inoparable, then compare the Demand Position Indication System and the Digital Rod Position Indication System at least once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

b CALLAWAY - UNIT 1 3/4 1-17

.- ~.

(p;

'a i

..?...

e...

t 7NSERT 1 b.

With more than one digitalirod position: indicator'per-' bank

' inoperable.either:

~

1.a) Determir ei the. position-of the: nonindicating rods indirectly by.the movable-incore: detectors at least-once per S hours and immediately after any'motioniof; the nonindicartncLrod which; exceeds 24 steps in'one:

direction 1since the last determinationfof the? rod?s position,Jand 1.b). Place the controlsroG3.under.manualJcontrol and limit-rod motionLas specified above,'and i

1.c) Monitor'and record React'or-Coolant System, average teinperature (T,yg)1at least once per.. hour,..and 1.d): Restore.the didital rod position indicatorse to OPERABLE -

status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> such-that a maximum'of-ona digital red'pesition indicator:per; bank':~is inoperable; or 2.

Be in HOT STANDBY;within'the next 6fhours;.

6 W

l l

l.

j:.

(

/

REACTIVITY 'ONTROL SYSTEMS' B_A5,f3 MOVABLE CONTROL ASSEMBLIES '(Con.tinued)l i

For purposes of determining compliance with Specification 3.1.3.1.

any immovability of a control rod initially invokes ACTION statement

.I 3.1.3.1.a. : Subsequently. ACTION,statomsnt '3.1.3.1.a may be exited and ACTIONS statement 3.1.3.1.d invoked-if either the roc control' urgent failure alarm is -

1 illuminated or an electrical problem is detected in the rod control system.

1 The rod is considared.trippable if the rod was demonstrated.0PERABLE during:

l the last performance of Surveillance Requirement = 4.1.3.1.2 and' met the rod -

drop time criteria of Specification 3.1.3.4 during the last performance of 1,

Survalliance~ Requirement 4.1' 3.4. -

The ACTION statements which permit limited variations from the basic requirements are accompanied by' additional restrictions' which' ensure 1that the;

~

. iginal design criteria are met. Misalignment of, aLrod requires measurement of peaking factors and a restriction in THERMAL POER.

These. restrictions r ovide assurance of-fuel rod integrity during continued operation. 'In addition o tnose' safety analyses affected1 by a misaligned. rod are Lreevaluoted to! confirm

-that the' results remain valid d. ring future-operation.

tr ;r?VU25c7 ;l The maximum rod drop time restriction is ecnsistent with the assumed rod 1

drop time-used in the safety analyses.. Measurement:with T,yg; greater than or.

equal to fil'F'and with all reactor aolant' pumps operating ensures that the measured drop times will be. representative.of insertion:timesLexperienced during a Reactor trip at operating conditions..

Control rod positions and OPERAB'IL:TY of the rod position ir.dicators ara required to be verified on a nominal basis'of-oncesper 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> with oore 1n frequent verifications required if an automatic monitoring chhnnel is inoperable.

These verificaticn frequenctei are adequate for assurirg that the applicable LCOs are satisfied.

4

.i

{-

CALLAWAY - UNIT l B 3/4'l-4 Amentnent~ No. 51 O

N

+

+

s INSERT 2 The power reduction and shutdown time limits giventin-ACTION-6 statements 3.1.3.2.~a.2, 3.1.3'2.b.4,.and.3.1.3.2.c.2,.

'respectively, are initiated at'the time of discovery that the

-compensatory actions: required for POWER OPERATION'can'no-longer

-be met.

I-i L

I

i i

j 1

)

.I t

t I

')

l l

x.

a..

=

b j

I;

~

+.

)

i

i 1

-I ULNRC-2282:

}

i l

ATTACHMENT TWO

=!

j t

SAFETY' EVALUATION 4

f

,l i

j i

t i 1

1

.- i i

f c

--^n,-

m.,

i c

~

N j

]

'3AFETY EVALUATION 4

)

This amendment application requestsia. change to. Technical Specification 3.1.3.2 to add an Action Statement covering i

situations where moreithan'one' digital rod position indicator (DRPI),per bank is inoperable.

This new Action Statement avoids l

unnecessary plant shutdowns per Technical: Specification 3.0.3 yet

-is. consistent withLthe overall' protection: afforded by related Specifications.

For example, Action' Statements 3.1.3.1.cfand H

3.lt.3.1.d,,which are associated with known control rod misalignments,~ rod. control l urgent failure alarms, or other.

i electrical' problems, do not invoke compensatory measures as restrictive as.3.0.3.

In fact', Action. Statement 3.1.3.1.d; allows operation with~one or more inoperableirods (due to' rod: control.

r urgent failure alarm lor other electrical problemtin the 'rcxii.

control system) for 14) to 72:hourr

• The situation addressed in this ' amendment. application is one which indication is lost =,-

j with compensatory actions taken.

ng the:2* Neur allowed outage tima (A0T); however, there are t nown misalignments'or rodi j

co'atrol operahility concerns.

P Callaway has 53 full-length. rod cluster control assemblies l

(RCCAs) arranged in four control banks =(A-D):andifive~ shutdown.

3 l

banks (SA-SE).

With the exception offshutdown1 banks: SC, SD'and SE, each bank is divided into.two: groups..Each group,'in turn,'

consists of iseveral assemblies whicP move together.- EachiRCCA has a. position indicator. channel which' displays theLpositionlof-the assembly.

The indication.of4RCCA position-, in accordance.

i L

with Regulatory duide 1.97, is a_Categoryc3 variablec(i.e.,-

'3 non-Class 1E, performance' grade).

Fully' inserted' assemblies'are further indicated by a rod at: bottom signal which actuates-a local alarm and a control room annunciator. ! Group demand-position is also indicated.

RCCAs are moved in preselected banks, andLthe banks are' moved in tho~same preselected sequence.

In the banks with tw6 groups, the rods comprisingLa group operate in' parallel through multiplexing thyristors.

The two groups in:these banks. move sequentially'such-that the first group is within one step'of the second: group in-the bank.

A definite schedule.of actuation (orcdeactuation) of the stationary gripper, movable gripper, and lift coils ofoa i

mechanism is' required to. withdraw the.RCCA attached'to the.

mechanism.

Two separate systems are provided to sense and display control rod positions as described below:

L a.

Digital rod position indication system The digital rod. position indication (DRPI) syster.

l measures the actual position of;each control rod, using j

l

i a detector.which consists'of: discrete. coils mounted 1 concentrically.with the rod-drive pressure housing.

The coils are located axially along the' pressure housing,and magnetically sense the entry;and presence of the rod: drive shaft'through0its; centerline.

Fort cach' detector, the coils,are' interlaced:into-two: data:

1 channels,'and are' connected to the; containment

electronics >(Data A and B):by. separate multiconductor:

~~

cables..By employing-two separate 1 channels of' j

information, the DRPI system'can continue to function (atLreduced accuracy)-when one channel fails..

Multiplexing'is used to transmit the digital ~ position 1 signals' from.the containment electronics to-the control board'displayLunit.

i The' control bo~ard display unit contains~ a column-of

' light-emitting-diodes-(LEDs) for:each rod.- 'At any given time,'the one. LED illuminated-in each column shows the position ~for that particular1 rod.1 ;Each1rodLof the control banks. has its position displayed tol14.

1 steps throughoutits range of tratel from rod: bottom:to; 228 steps.' - Since-shutdown rods a.s'always'fv117 -

l withdrawnL with: the plant at pow er, their positionLis displayed to 14 stepsionly from rod' bottom to 18Lsteps and fromL210 steps to 228 steps. ;All intermediate, positions ~for the shutdown' rods'are. represented byla single " transition"' LED.

j q

p-Included in'the system is a. rod at bott'omisignal for; each rod that operates a localnalarm. 'Alsolaccontrol room annunciatorJis actuated'when anyHshutdown rod or-control bank A rod is at bottom.

b.

Demand position system

[

The demand position' system counts pulses generated in the rod > drive control: system to provide'a digital readout of.the. demanded bank position.

The Gemand position and DRPI systems are separate systems-as a l

result of operational requirements (i.e.,uno safety criteria were-involved in the separation). LOperating proceduressrequire the reactor operator to compare the demand'and indicated (actual) readings from tha DRPI system so as to verify operation =of the.

rod control system.

i The proposed change does not involve an unreviewed safety question because operation _of Callaway' Plant with this chance would not:

l-l l

{

E '

- - - -... - - - - -. -. - - - 1

j 7 H:

i

~

' (1)' Involve an increase in the: probability-of occurrence or the consequences of an accident:or: malfunction of equipment

l important to safety previously. evaluated in the FSAR.

Sincef no design changes are. involved'with this amendment request, the impact on the plant safety analysis design basis would.

be.one involving a reactivity transient induced by operator.

error associated with,the loss of position indication. LThe aaalysis results for these_ events in FSAR Sections 15.4.1 -

15.4.3 is_not dependent upon_ operator acts of-omission:or-commission. -The assumed reactivity' insertion rates aret.

based on conservative, worst case, scenarios independent of whether'they are due:to, equipment malfunction or human-

. error.

Loss of RCCA position indication.would not affect the-assumed reactivity insertion rates.

Further, the.

protection systems assumed;in the analysis of these; events; (power range neutron flux-highcand low settings and OT-Delta T) are unaffected sincezno design changes'are involved.-

The worst case reactivity transient of this: nature, the withdrawal of a single RCCA, hasfbeen analyzed-in FSAR Section 15.4.3 assuming that operators ignore RCCA position

-indication..Whether indication is lost, as is the case-covered by this new Action Statement', orndisregarded does l

l not change.the method of analysis or theEoutcome of this~

event.

I L

(2)

Create the possibility for an accident or malfunction of a different type than any previously. evaluated-in the'FSAR.

This is based on the. fact that no design. changes are involved.

The new Action. statement has an allowed outage time of 24' hours as well as compensatory actionsito use the movable incore detectors to ascertainHrod' position, to monitor and record Reactor--Coolant.. System (RCS) temperature,.

to place rod control in the manual mode, anditoElimit rod motion to the extent possible viaLthe'use-ofiother reactivity control mechanisms such-as boration and The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT provides sufficient. time to trouble: dilution.

shoot and restore the DRPI Uystem to operation.while avoiding the plant challenged associated with an unnecessary shutdown.

Monitoring and recording RCS temperature.would' allow early detection of mispositioned or dropped rods.

Overall; plant safety would be enhanced by maintaining steady state operation, as compared with the large rod movements, and potential challenges, required duringian unnecessary shutdown in conjunction kteh the loss of DRPI.

.The new-Action Statement is co." istent with'the overall protection

~

afforded by related c u _1fications.

(3)

Involve a reductivt in tle margin of safety.as defined in-the basis for any lechn'. cal' Specification.

The proposed change will not result in a decrease in the minimum DNBR given in Bases Section 2.1.1 and reported in the FSAR.

Bases Section 3/4.1.3 states that the Specifications of this section ensure that:

r i

3-

+ -, _ _

- + -

.s

=

m er

=

w-w

+* +,

,t=

rr

-r----

-ee-d

l

,e.

c-a) acceptable = power distribution' limits'areJmaintained,.

b) the' minimum SHUTDOWN; MARGIN is maintained, and c)-

the potential effects of' rod misalignment on associated:

accident analyses are limited.

l l

The compensatory l actions requirefthatorod position be' i

determined indirectly via thelmovableLincore: flux detectors and that-RCS. temperature be monitored and' recorded.

This-addresses: a) and b) above.

Also,. rod control ~is placed11n<

manual and rod motion is climited.' This: addresses c)1 above. -

There is aj5% uncertainty margin included in the designo i

valueJof power: peaking factoriassumed in the-analysis of Condition I and II transients.

The movable incore detectors-

.are. capable:of-revealing any situation which;causes power shapes to-be-peaked'in excessLof1the desi~gn'value._

Asymmetric power' distributions:can also be detected by the r

excore neutron' flux' detectors ~and: core exit thermocouples.:

FSAR Sections 7.7.1.9 and 7.7.2.2 provide further-1 p

discussions on the capabilities of these systems.

q t

-Given the above discussions as1well--as_those in then ignificant' s

l' Hazards Evaluation, the. proposed: change does not adversely _ affect or endanger the health or safety of the general-public.

1 l'

l p

1.

l L

l 4-y i

~

t

r,:.

. +

i i

4 6

l' 1

.i

l t

ULNRC-2282 -

1

- i

. A T T A C HItl 2TT T H R E E -

' i 1 ~

j_

SIGNIFICANT HAZARDS: EVALUATION l

l:

r T

k r

i 1

l r

i i

I.

r 1

l l

1 l

l r.

t i-.

4

+s

5.

.s5

?

a 2

SIGNIFICANT HAZARDS; EVALUATION This amendment ~ application ~ requests'a change to-Technical specification 3.1.3.2 to addLan: Action Statement' covering

- situations where more-than one; digital rod position indicator.

(DRPI)'per bank is inoperable.

Thefsituation addressed in this amendment application ~is onesin whi'htindicationnis' lost, with' c

s compensatory' actions taken during'the proposed 24' hour allowedL

- outage time (AOT); however, therejare.no known rod cluster control assembly (RCCA). misalignments or rod control operability Concerns.

The proposed change does.not-involve a_significant hazards consideration-because operation-of Callaway Plant'with this; t

change would not:-

~

(1)

Involve a significant. increase >inithe probability or consequences of an accident previously. evaluated. ;The-potential-for the newtActionLStatement:tolimpact,the safetyu

~

analyses of_the plant:liesconly in7the areaLof operator-exacerbated reactivity events due to'a loss of'RCCA position indication.

RCCA events.such as:

a)

One or more: dropped'RCCAs withinLthe same s

group (FSAR Section 15.4.3)-

b)-

Dropped:RCCA-bank'(FSAR.Section'15.4.3) c)

RCCA ejection-'(FSARJSection'15.4.8)-

are not impacted sinceithe new Action. Statement does'not involve a design change that would. affect the probability of these events occurring nor their consequences.

As.such, the-events of interest are:

1) Uncontrolled RCCA. bank withdrawal from a subcritical or lowLpower startup condition (FSAR Section 15.4.1).

11) Uncontrolled'RCCA bank withdrawal'at power (FSAR Section 15.4.2) lii) Statically misaligned RCCA (FSAR Section 4

15.4.3)

IV) Withdrawal of-a single RCCA (FSAR Section 15,4.3)

The first two events'are Condition II transients.that:have been analyzed using a positive reactivity insertion rate that is greater than that for.the simultaneous withdrawal of

~

the two control banks having the maximum combined' worth'at maximum speed.

Whether these-events are-caused-by a failure in the rod control system or by operator: error-has no effect on the positive reactivity insertion ~ rate assumed'in these analyses.

The protection systems assumed in the analysis:of these events (power range neutron flux-high'and low settings and OT-Delta T) are unaffected'since this amendment docs not.

1-m' i -

2

.m

..,,m._

.-,.yw.,

so y

,.., y

w t

ac..:

involve a design change.2 Therefore', the new Action J

Statement would have no_offect'onfthe analysis.of these-events and the DNBR-design basis would still'be met..

]

The most severe misalignment situations with: respect to DNB-i

~

arise from cases in which onelRCCA is-fully inserted, or.

[

where' bank D?is-fully inserted'to its insertion limits with one'RCCA fully withdrawn. :For these' cases',;as discussed-in:

FSAR'Section 15.4.3, theiDNBR remains'aboveithe safety-analynis limit. values..-The new1 Action (Statement-proposed:

herein does not alter these:results.

.{

-The compensatory actions: associated with this new ' Action ~

Statement, placing;the' control rods 1under-manualicontrol'and--

limiting rod motion., address concernsJassociated withi automatic: rod-motion'due'toothe:rodLcontrol system and-with inadvertent operator contribution"to these events.

1q The' worst case event-of the above, the withdrawal'ofLa single"RCCA,.is a Condition 4IIIsevent. -It has been:. analyzed;.

in FSAR Section 15.4.3' assuming that.the operatorsnignorej.

RCCA' position indication or-that: multiple rod control systems failures occur.

No single electrical or mechani' cal failure J

in-the rod control system could cause~the1 accidental-1 withdrawal of a single-RCCA from-a partiallyLinserted bank at full power operation.'

The operator:couldideliberately u

withdraw a-single _RCCA in the control bank;'this-.featureLis necessary in order to retrieve a rod, shouldLoneibe sccidentally dropped.- This new Action' Statement does' noti ehange the plant-designr therefore, there wouldLbetno change j

in the probability of'this event being induced"byJunlikely,-

-j simultaneous electrical failures-(see further! discussion?in 1

FSAR Section 7.7.2.2).

Further, whetherfindicationcisilost, as is the: case covered by this"new Action Statement, or-l i disregarded does not change the method of analysisJor-the outcome of this event.

(2)

Create the possibility of a new or difforent kind of accident from any previously evaluated.

This;isibased on

~

4 the fact that no design changes are involved.

The new Action Statement provides sufficient time for i

troubleshooting while. avoiding unnecessary plant shut' downs per Technical Specification 3.0.3' The compensatory actions-require that rod position be inferred from flux' maps, that RCS' temperature be monitored and recorded, and that rod position changes be limited to the extent possible via other' reactivity control mechanisms such as~boration and dilution.

The new Action Sthtement is consistent'with the overall protection afforded by related Specifications.. - For example, Action Statements 3.1.3'.l.c-and 3.1.3.1.d,_which are:

associated with known control rod misalignments, rod control urgent failure alarms,por other electrical problems, do not invoke compensatory measures 's restrictive as 3.0.3.

In fact, Action Statement 3.1.3.1.d allows operation with 1

1 Y i

t a1

,, A v..

t

-one:or m' ore inoperableErods-(due;to rodLcontrol' urgent L

failure alarm or:otherfelectrical' problem;in the rod ~ control L

system)3for up'to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. gThe situation-addressed in-this L,

amendmentfapplication isione in which indication _is lost,_

with compensatorv actions taken during the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed outage time L( AOTi r however,..there are no known misalignments or_ rod controlioperabilitys oncerns.

4 c

L (3)

Involve a.significant reduction ~1n almarginiof' safety.

The l

, proposed" change will'not resultLin'a decrease!in the minimum-l DNBR given.in Bases 1SectionL2.1.1-~and reported:in the FSAR.

~

Bases Section:3/4.1.3 states that-theLSpecifications of this section ensure ~that:

a)L acceptable' power distribution / limits'are I

. maintained,

b).

the~ minimum ~ SHUTDOWN MARGIN'is-maintained,1 L

and' 1

c) the, potential effectsioforod misalignment on' associated accidentianalysestare limited.

The= compensatory actions, require.that rodLposition be r.

-determined indirectly via the movable-incorr,1 flux detectors'

.i

.and'that RCS temperature be monitored and-recorded.- This' a

addressesza)-and-b) above;-lAlso, rod contro1Lis placed;in manual and rod motion.is limited..This addresses c)Labove.

3" Asymmetric power distributions-canLalso be detected by the.

excore neutron fluxLdetectors-andLcore exit thermocouples..

t As-discussed above,.the proposed change >does not: involve a significant increase in.thesprobability or consequences of an accident.previously evaluated :or-create.thelpossibility of a new 1

or differentLkind of accident-from any previously evaluated.

'i This change does not result _in a'significant reduction in a.

margin ofssafety..Therefore,z it has been--determined that the proposed change does not' involve a significant hazards.

consideration.

i k '

s

.