ML20217C517

Summary of 910522 Meeting W/Representatives of Plant to Discuss DPC Proposal to Extend on one-time Basis Ice Weight Surveillance Interval.Proposal Approved.List of Participants & Presentation Encl

ML20217C517
Person / Time
Site:	Mcguire
Issue date:	07/03/1991
From:	Tim Reed Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9107170179
Download: ML20217C517 (23)

Text

_-___ _ _ _ _ _ _ _

July 3,1991 Docket No. 50-370 LICENSEE: Duke Power Company FACILITY: McGuire Unit 2

SUBJECT:

SUMi :Y OF MAY 22, 1991 MEETING On May 22, 1991, the NRC str.ff met with representatives of Dule Power Company (DPC) to discuss a DPC proposal to extend on a one. time basis the ice weight surveillance intern i for McGuire Unit 2 associated with Technical Specification (TS',3/4.6.5.1. The proposal is to extend the surveillance interval which currently comes due on August 3, 1991, until the next McGuire Unit 2 refueling outage currently scheduled for January 1992. The licensee's technical appro3ch is to examine the historical sublimetion rates for McGuire Unit 2, then choosing the worst case rate, multiply this rate by 150% for conservatism to account for unknowns. Ice basket ice weight is then projected to the January 1992 outage and shown to be greater than the TS limit.

The NRC staff believes that the DPC approach is conservative and that such an approach can be approved on a one-time basis for McGuire Unit 2. DPC is expediting the TS amendment package in order to have the submittal to the staff by June 5. [The amendment was indeed received by June 5, 1991.] The meeting participants are listed on Enclosure 1. Enclosure 2 is the presentation given by DPC.

/s/

Timothy A. Reed, Project Manager Project Directorate 11-3 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation

Enclosures:

1. Meeting Participants

2. Presentation cc w/ enclosures:

See next page

• See Previous Concurrence OFC :LA:PDII-3* :PM:PDII-3* :D:PDII-3*  :  :

NAME :R!ngram  : Treed :DMatthews  :  :

DATE :07/2/91 :07/2/91 :07/3/91  :  :

OFFICIAL RECORD COPY Document Name: MTG SUM /MCGUIRE 9107170179 910'703 !T -

k l.u b***,* W W,s4.44 O g f [-

PDR ADOCK 05000370 P PDR

} h

(

i

DISTRIBUTION _:_

Meeting Sunrnary - Dated July 3.1991 Facility: McGuire Unit 2 Docket file NRC & Local PDRs F. Miraglia J. Partlow S. Varga G. Lainar PDil-3 Reading

( D. Matthews T. Reed 0GC, 15B18 J. Pulsipher, 8D1 E. Jordan ACRS (10), MNBB3701

, P-315 J. Wechselberger, 17G21 McGurie Plant File h

. /p# 88 0p%o,

!\)g ' 'n UNITED STATES

?- i NUCLEAR REGULATORY COMMISSION o, k WASHINGTON. D.C. 20$56

, ' * ~....f July 3,1991 Docket No. 50-370 LICENSEE: Duke Power Company FACILITY: McGuire Unit 2

SUMMARY

OF MAY 22, 1991 MEETING On May 22, 1991, the NRC staff met with representatives of Duke Power Company (DPC) to discuss a DPC proposal to extend on a one-time basis the ice weight surveillance interval for McGuire Unit 2 associated with Technical Specification (TS) 3/4.6.5.1. The proposal is to extend the surveillance interval which currently comes due on August 3,1991, until the next McGuire Unit 2 refueling outage currently scheduled for January 1992. The licensee's technical approach is to examine the historical sublimation rates for McGuire Unit 2, then choosing the worst case rate, multiply this rate by 150% for conservatism to account for unknowns. Ice basket ice weight is then projected to the January 1992 outage and shown to be greater than the TS limit.

The NRC staff believes that the DPC approach is conservative and that such an approach can be approved on a one-time basis for McGuire Unit 2. DPC is expediting the TS amendment package in order to have the submittal to the staff by June 5. [The amendment was indeed received by June 5, 1991.] The meeting participants are listed on Enclosure 1. Enclosure 2 is the presentation given by DPC.

s }

Timothy A. Reed, Project Manager Project Directorate 11-3 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation

Enclosures:

1. Meeting Participants

2. Presentation cc w/ enclosures:

See next page

o

{ .

McGuire Nuclear Station CC:

Mr. A.V. Carr, Esq. Dr. John M. Barry Pule Pcwer Cor:peny Departirent of Environmental Health 422 Scuth Church Street Mecklenburg Cour.ty Charlotte, Nc th Carolina 28242-0001 1200 Cbthe Coulevard Charlotte, North Carolina 28203 County Manager of Mecklenburg County 720 East Fourth Street Mr. Dayne H. Brown, Director Charlotte, North Carolina 28202 Department of Environmental, Health and Natural Resources Mr. Paul Guill Division of Radiation Protection Duke Power Company P.O. Box 27687 Nuclear Production Department Raleigh, North Carolina 27611-7687 P.O. Box 1007 Charlotte, North Carolina 28201-1007 Mr. Alan R. Herdt, Chief Project Branch #3 U.S. Nuclear Regulatory Commission J. Michael McGarry, III, Esq. 101 Marietta Street, NW, Suite 2900 Winston and Strawn Atlanta, Georgia 30323 1400 L Street, N.W.

Washington, DC 20005 Ms. Karen E. Long Assistant Attorney General N. C. Department of Justice Senior Resident inspector P.O. Box 629 c/o U.S. Nuclear Regulatory Commission Raleigh, North Carolina 27602 12700 Hagers Ferry R 9d Huntersville, North Carolina 28078 Mr. R.L. Gill, Jr.

Nuclear Production Department Regional Administrator, Region 11 Duke Power Company U.S. Nuclear Regulatory Commission P.O. Box 1007 101 Marietta Street, N.W., Suite 2900 Charlotte, North Carolina 28201-1007 Atlanta, Georgia 30323 Mr. M. S. Tuckman Mr. Frank Modrak Vice President - Nuclear Operations Project Manager, Mid-South Area Duke Power Company ESSD Projects P. O. Box 1007 Westinghouse Electric Corporation Charlotte, North Carolina 28201-1007 MNC West Toser - Bay 241 P. O. Box 355 Pittsburgh, Pennsylvania 15230

}C(TMDM ' LTST 5/1stIt ORsnur2AnzaA} h)A M 5 i 11At/pgrz/FM Jg Rczo/

N M /MfR'f'SNB Jun Rls skip He~$4er wx

Me se c.,4awa u ea - / A a ,a.et. ,-so s,.u m g Dde Awer 0/4(Mwe &bh/.axb Me r.,ca/s,ca..,e Ax ka AKE ber-[NPP-NsA-Rec,o 74ql 6wi} }

Enclosure 1

DUKE I

s

1. 4H! ...

POWER g

T COMPANY

1 q i $l[ MCGUIRE

, @ NUCLEAR

$m STATION I > lih;;

M UNIT 2 ICE CONDENSER I

O TECH SPEC 3/4.6.5.1

, , ,r i l AMENDMENT A NRC PRESENTATION OVERVIEW

1. MAY 22,1991

%? 1.

,S

-t i3 r

Enclosure 2

I*

DUKE POWER COMPANY MCGUIRE NUCLEAR STATION AGENDA MAY 22,1991 MEETING WITH ONRR ONE TIME TS Ah01NDMENT FOR UNIT 2 ICE BASKET WEIGHING SURVEILLANCE I. Introduction / Opening Remarks P. F. Guill II. Presentation N. A. Smith,III

- Background

- Current Technical Specification Requirements

- Proposed Ice Weight Reduction TS Amendment

- Ice Basket U-Bolt Issue

- One Time Technical Specification Amendment (Unit 2)

- Technical Justification III. Discussion / Closing Remarks P. F. Guill IV. Caucus NRC

l MCGUIRE NUCLEAR STATION UNIT 2 ICE CONDENSER SURVElLLANCE WINDOW EXTENSION TECHNICAL SPECIFICATION AMENDMENT ICE CONDENSER:

SYSTEM PURPOSE The lee Condenser's primary function is to mitigate the containment pressure consequences associated with a Loss Of Coolant Accident or Main Steam Line Break inside containment.

i AER 98.TEI.WT1 3 M DUCT.

'" N  ::: h# m"u.

umc. - n:: N k  ::::

) MW i

{ f o

== ( 1 g it J

i Q --

>. m k<4 ,

mm sem

.. p..

m - - - - - -_ - - - - - - - - _ - - _ - - - -

m ,

BACKGROUND s EXPIANATION OF ICE BED

.RDW GROUPS; i

E!!

-e D m

1. se

~ ~

[/ / // :~::::

12 13 u

14

/l @ 13 3 t

'k p 4 2  % s s

\

sv< q-6 , ,

\

., .. 6 -% / g .

4 d$ hY_ e

_s ,

e

\s0y .

7 q 5 "

s l. 5 ;N  ;\ ,

~ .r/N, Q s

i' t 1-s x

'; /

-Q , , _

F GRDUP O' 2 3, '.,, BAY

W .

j

/ Y COLUMN 3-

/

7 1

,_ _-2 3 4 5 6 7 8 9

-- COLUMNS EhYS \\ 000000000 !

i t arO00000000l 3 { 0000^O000 I 4 tOOOOOOOOC, el000000000 ROVS ~l OOOOOC>OOO I 7 CCCM4>CO I e CCCCCCCCOf 9 ju.- CLCCCCCCO )!

BASKET ARRAY 7

I I

I f

t. _. _ . . _ _ - . _ _ . . _ . . _ , _ . . _ . . _ . _- . . . .

7 s- J b

MCCUlRE NUCLEAR STATION

- UNIT 2:lCE CONDENSER- -

SURVEILLANCE WINDOW EXTENSIONi TECHNICAL SPECIFICATION AMENDMENT  :

1

-TECllNICAL SPECIFICATION-

< LIMITING CONDITION OF OPERATION McGuire Technical Specification Limiting Condition of Operation 3.6.5.1,d defines a minimum acceptable total ice weight of 2.466,420 (2,099,790*) lbs at a 95% level of confidence.

SURVEILLANCE REQUIREMENTS Surveillance Requirement 4.6.5.1.b.2 further specifies:

- Of a-144 basket sample (0/ bay), all must contain a minimum 1269 (1081') lbs of ice. For a basket below the minimum, additional baskets from the same bay must contain a -

minimum mean ice weight of 1269 (1081') lbs of ice.at a 95%

level of confidence.

--The mean basket ice weight at a 95% level of confidence from each row group must be greater than 1269 (1081'l lh.s

- Thew total ice weight at a 95% level of confidence must -

be greater than 2,466,420 (2,099,790') Ibs.

Denotes ice weight reduction amendment, submitted June,1990.

+

e--g,- --

y e- q- ww,n y um

• m m w w -

1. . .

MCGUIRE NUCLEAR STATION UNIT 2 ICE CONDENSER SURVElLIANCE WINDOW EXTENSION TECHNICAL SPECIFICATION AMENDMENT ICE WElGilT REDUCTION TECil SPEC AMENDMENT:

PURPOSE The amendment to Technical Specification 3/4.6.5.1 to reduce the minimum required ice weight was submitted to preclude mid-cycle ice basket replenishment outages during the forthcoming longer cole cycles.

BASES The Technical Specification amendment is justified by a LODIC analysis defining postulated containment pressure / temperature transients within design limits with reduced ice weight.

EFFECT ON PEAK CONTAINMENT PRESSURE PEAK CONTAINMENT TECH SPEC ICE WElGHT PRESSURE LIMll 2.220,000 lbs 12.36 psig 14.8 psig 1,890,000 lbs 14.07 psig 14.8 psig STATUS NRC approval expected shortly.

- - - - - - - - - - - _ _ - - - - _ _ _ _ _ _ _ ___,a__ _ _

l' U-BOLT ISSUE GENERAL ASSEMBLY u ii. ..., =

Q d' "

O O O 00; Pit,ttaflDet '

l l ,

.2 Cf T R M. 60 P(8,0 tait 0SAlitT W ,

C-

)

] i i

3T...< -

O  :

1 m4 g g.c g.g g.g g: e Offtsf L h

(h r>s'~r'Es'O.~[S~E~E~M O~ 142.57 Rif a .

N Nd b PLAft CXl t

I i

7  :

l E]A./  !

-, L i . . ..

g .g .gg}iggggj i

I '

N lattti 59  ! ' '

L. . - - - .- - ;e,x; w - __---_- _-

_ -_- J "

vist uts.

~ '

W U ' '

f ,U [ - s . co W6USTIB4 9.ACI(T Al DetLT CLfvt3 Pie tvolCAL BOTTOM 501 5ASKET A55!=8LY is McGUIRE NUCl.EAM STATION Figwre 6.2.0-3

h .

4-MCCUlRE NUCLEAR STATION UNIT-21CE CONDENSER SURVEILLANCE WINDOW EXTENSION.

'TECllNICAL SPECIPICATION AMENDMENT I

U-BOLT ISSUE:

I FAILURE MODE Duke determined the failure mode of the U-Bolts to be a result of

-a manufacturing flaw propagated by construction / maintenance induced loads.

OPERABILITY EVALUAT10" I A nroof load test was performed on a large population of U-Bolts-demonstrating their integrity and an extremely low failure rate. 1 The test established the U-Bolt's integrity for one load cycle of design basis magnitude. As the loads induced during ice weighing were considered significant, the Operability Evaluation for both Units excluded on-line ice weighing using current techniques.

.LONG TERM PLAN-During the upcoming retueling outages on both McGuire Units, a-phased replacement of U-Bolts will begin. The bolts, mounting bracket, and associated hardware will be replaced with a swivel base bracket. The bracket not only eliminates U-Bolt. concerns, it i

enhances the on-line weighing technique. Replacement is expected to take 4 refueling outages. '

i .

1 l EFFECT ON ICE WElGHING y On-line ice weighing cannot be performed under the current l- ' surveillance requirements. The initial population of upgraded ice i

baskets will include those for the mid-cycle ice weight l surveillance. These baskets may be weighed on-line, reestablishing j the ability to meet the Technical Specification requirements.

4 i

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

4 U-BOLT U-BOLT ISOMETRIC VIEW w

.,,,e ja,,.

b'3 hk y ggPe y ~;' ,p. ..

q sr s -

V h

SWIVEL MOUNTING BRACKET ISOMETRIC VIEW r

S F

l! ! ".

, j p s!o

-i tj p

=

F

..s

P MCGUIRE NUCLEAR STATION UNIT 2 ICE CONDENSER SURVEILIANCE WINDOW EXTENSION TECHNICAL SPECIFICATION AMENDMENT REQUESTED TECllNICAL SPECIFICATION AMENDMENT:

REQUEST Amendment to Technical Specification 3/4.6.5.1 extending the ice weight surveillance interval for Unit 2 Cycle 7 to the next refueling outage.

PURPOSE Preclude a mid-cycle outage during Unit 2 Cycle 7 to perform a Tech Spec surveillance.

CONSEQUENCES IF NOT OBTAINED Implement less desirable options.

- Perform on-line weighing of non-ejectable baskets

+ Requires relief from current surveillance rec,uirements

- Perform off-line ice weight surveillance.

7 MCCU!RE NUCLEAR STATION UNIT 2 ICE CONDENSER SURt!P;LiANCE WINDOW EXTENSION TECllNICAL SPECIFICATION AMENDMENT TECllNICAL JUSTlFICATION:

OVERVIEW The approach to technically justify the amendment is based on a projection of current ice weight through the fuel cycle. Beginning of Cycle ice weight data, worst case historical sublimation rates, and a multiplier (150r)o for unknowns were used in a linear extrapolation of ice weight through the fuel cycle.

TECHNICAL JUSTIFICATION HISTORICAL BAY SUBLIMATION RATES

!' MCGUIRE NUCLEAR STATION UNIT 2 i BAY SUBLIMATION RATES

! EMSED ON 95% LOC BOC TO EOC DATA l

j CK1E3 i

i

\m N -=

f ~

12 N 10 M

! FMT5 N

5 (wmann) j ,

! \ x s0 1

3 f ..

4 i 6

! GROUP l

l l CYCLE 4 l

l <=

l 4

- \ -=

N-10 i 1

.q $ s

-<~-.>

0

=

J' '

• row ' , ,,

i caoog 4.__ _ _ _ _ _ _ _ . . .

(

, TECHNICAL JUSTlFICATION l HISTORICAL BAY SUBilMATION RATES

! MCGUIRE NUCLEAR STATION UNIT 2 I BAY SUBLIMATION RATES i WED ON 95% LOC

! W TO EOC DATA l

l i

NS l

f ~"

! _ NL15

' N s 10 g 7

Mu i s-s (Ibs/more; s

\

I ,

o 1

l

• 4 I

"U* ,

7 S

~ GROUP WS I'

i i s Nm r ~ x,.

f \ 10 g i ' .

RATE

-s (ibs/more; j jN

, o l

j *

,w #

I ROW I 's 1 9

GROUP W

.k MCGUIRE NUCLEAR STATION UNIT 2 ICE CONDENSER SURVEILIANCE WINDOW EXTENSION TECHNICAL SPECIFICATION AMENDMENT TECHNICAL JUSTIFICATION:

WORST CASE SUBLIMATION RATES UNIT 2 MAXIMUM HISTORICAL R0W GROUP SUBLIMATION RATES CYCLE 2 THROUGH CYCLE 6 BASED ON 95% LOC B0C TO ECO DATA SUBLIMATION RATE 801 GROUP ClCLE (lbs/ month) 9 3 4 18.9 9 2 5 18.8 9 1 6 16.0 9 1 4 15.6 9 3 5 14.7

3. .

L. /

L

MCGUIRE NUCLEAR STATION 7 UNIT 2 ICE CONDENSER SURVEILLANCE WINDOW EXTENSION:

TECHNICAL SPECIFICATION AMENDMENT TECllNICAL JUSTIFICATION:

METHODOLOGY -

Using the following formula to project ice weight throughout cycle _7.

Wt = W-bec - SR x M SR x ( Dt - Dboc )

- Where:

W.t -= Projected mean ice weight for row 'a' group.'b' at time

,t,-

Wb oc = Beginning of cycle surveillance mean ice weight at a 95% level of confidence for row 'a' group 'b'-

SR = - Sublimation rate, worst case historical (Ibs/ month)

MSR = Sublimation rate multiplier, accounts for uncertainly l

Dboc = Beginning of cycle date (month) l Dt -= Date at time 't' (month)

L

~j 1

i i

UNIT 2 CYCLE 7 ICE BED j ICE WEIGHT PROJECTION

SUMMARY

BASED ON 150% OF WORST CASE SUBL RATE 3 l

t=3 T C Group 1 Group 2 Group 3

<a u a.,

soc e. ,~

yy

g3 l

! e^sxar

,o soc w w.3,n, as x3 G

a.

. . m. , @a m>

800 EOC soe Weq;N Proposed $%

\

200 Propo +dTan sp.o i o , ,, , ,ii,ii,ii ,, , , i,i i i , i i

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

555555555 55555555 555555555 i

I i

i n

UNIT 2. CYCLE 7. ROW 9. GROUP 2 WORST CASE 8CE WElGHT PROJECTIONS $

x a

18CD -r (""3 C

> Z

• 1P Cn z tsoo -

- -e- - - WorW Case $5%

te s e n>

Q t'J F l

,, - ---*--- t m eewarWc sn gg as a aw, ore g _-

=d O

'z=

BASKET ixo _

e =

,ce .

- -s2 WOGHT .

P'*****d W N

@*)

taco K- T m >O 118

' j"57 3 p soc 7.n a tsoo 8. Qd w

1081 h GOC 7 m , ..az 3

,o ., # Proyecton LPd.

2 F emary27.1ser l l [

Ncr#40 M Mar-81 Apr41 M J4-81 See st Nere81 Dod Fot>S2 Apr42 l DATE r P I l

~

MCGUIRE NUCLEAR STATION I UNIT 2 ICE CONDENSER SURVEILLANCE WINDOW EXTENSION TECllNICAL SPECIFICATION AMENDMENT CONCl,USIONS:

The conservative analytical approach towards projecting ice weight ,

demonstrates that with a high level of confidence, adequale ice mass will exist in the Unit 2 ice condenser at the end of cycle 7.

Projections indicate the end of cycle worst case mean ice weight will be 116 lbs above the Tech Spec limit, that required at the beginning of cycle. The request for the extended surveillance interval is e therefore technically justified.

i i

I t

, _ e-l

'.+A,

.9.7-- -. .y , - _ - - , . , _.,...._,..,# . , . . - _ _ _m,,,,, . ~ , . , -- . ..v.',,y,.,%..-w.,,,,.., ,__.m.,,,, ,y..v.,