ML20203A264

Summary of 980127 Meeting W/Illinois Power Co in Rockville, Maryland Re Potential Fix for Issue of Degraded Voltage at Clinton Power Station.List of Meeting Attendees & Copy of Meeting Handout Encl

ML20203A264
Person / Time
Site:	Clinton
Issue date:	02/03/1998
From:	Hopkins J NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9802230325
Download: ML20203A264 (29)

Text

.. .___ - ___ - _ _ -_- _ - -

.i' ,

Fe.bruary 3,1998 LICEt'SEE: . Illinois Power Company FACILITY: Clinton Power Station

SUMMARY

OF JANUARY 27,1998, MEETING ON DEGRADED VOLTAGE On January 27,1998, NRC management and staff met in Rockville, Maryland, with representatives of Illinois Power Cornpany. The purpose of the meeting was to discuss the potential fix for the issue of degraded voltage at the Clinton Power Station. A llat of the meating participants is included as Attachment 1, and a copy of the meeting handout is provided as Attachment 2.

The licensee discussed the current electrical design of Clinton. Then the proposed fix of two static var compensators on the 4kv bus and nine 480/120 voit regulating transformers was discussed. The proposed design is forward looking and considers future grid load without new l transmission lines or generating facilities.

l The NRC staff was interested in the failure modes analysis that has been performed. The j ficensee stated, that based on the staff's concern, they would review the analysis. The licensee is still reviewing the proposed modification and t as not made a determination as to wh ...er a license amendment would be needed. The schedule is to have the modification in place prior to plant startup.

Original signed by:

Jon B. Hopkins, Senior Project Manager Project Directorate 1113 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket No. 50-461 Attachments: 1. List of Meeting Participants 2, Meeting Handout cc w/atts: See next page DOCUMENT NAME: G:\CLINTON\0127.MTS OFFICE PC3 3:PM C- PD3 3:LA D NAME- Mopkins y EBamhill QW 3  !

.DATE M//98 f/

OFFICIAL RECORD COPY M/98 _ M d-  !

9002230325 900203 PDR ADOCK 05000461 P PDR llililllll,Ill llll o

'i -

Fsbru:ry 3, 1998 LICENSEE: lilinois Power Company FACILITY: Clinton Power Station j

SUMMARY

OF JANUARY 27,1998, MEETING ON DEGRADED VOLTAGE On January 27,1998, NRC management and staff met in Rockville, Maryland, with representatives of Illinois Power Company. The purpose of the meeting was to discuss the potential fix for the issue of degraded voltage at the Clinton Power Station. A list of the meeting !

participants is included as Attachtnent 1, and a copy of the meeting handout is provided as l Attachment 2.

l The licensee discussed the current electrical design of Clinton. Then the proposed fix of two static var compensators on the 4kv bus and nino 480/120 voit regulating transformers was discussed. The proposed design is forward looking and considers future grid load without new transmission lines or generating facilities.

The NRC staff was interested in the failure modes analysis that has been performed. The licensee stated, that based on the staffs concem, they would review the analysis. The licensee is still reviewing the proposed modrfication and has not made a determination as to whether a license amendment would be needed. The schedule is to have the modification in ploce prior to plant startup.

Original signed by:

Jon B. Hopkins, Senior Project Manager Project Directorate !!i 3 Division of Re:ctar Pro}ects lil/IV Office of Nuclear Reactor Re; *-*i)n Docket No. 50-461 Attachments: 1. List of Meeting Participants

2. Meeting Handout cc w/atts: See next page DOCUMENT NAME: G:\CLINTON\0127 MTS OFFICE PD3-3:PM C- PD3 3:LA 6 l NAME JHopkins W EBamhill QW l DATE- ?f//98 f/ Mj/98

)- OFFICIAL RECORD COPY

q' **:ty y* kP UNITED STATES s*  ; NUCLEAR REGULATORY COMMIS810N WASHINGTON, D.C. 30006 4 001 s . . , * )' February 3, 1998 LICENSEE: filinois Power Company FACILITY: Clinton Power Station

SUMMARY

OF JANUARY 27,1998, MEETING ON DEGRADEP VOLTAGE On January 27,1998, NRC management and staff mG in Rockville, Maryland, with I representatives of Illinois Power Company. The purpose of the meeting was to discuss the l

potential fix for the issue of degraded voltage at the Clinton Power Station. A list of the meeting participants is included as Attechment 1, and a copy of the meeting handout is provided as Attachment 2.

The licensee discussed the current electrical design of Clinton. Then the proposed fix cf two static var compensators on the 4ky bus and nino 480/120 voit regulating transformers was discussed. The proposed design is forward looking and considers future grid load without new transmission lines or generating facilities.

The NRC staff was interested in the failure modes analysis that has been performed. The licensee stated, that based o,. 6he staffs concern, they would review the analysis. The licensee is still reviewing the proposed modification and has not made a determination as to whether a license amendment would be needed. The schedule is to have the mudification in place prior to plant startup.

i e

4 Jon B. Hopkins, Senior roject Manager Project Directorate lll 3 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket No. 50-461 Attachments: 1. List of Meeting Participants

2. Meeting Handout cc w/stts: See next page v

Clinton Power Station, Unit 1 -

Illinois Power Company cc:

John G. Cook lilinois Department of Nuclear Safety Senior Vice President Office of Nuclear Facility Safety Clinton Power Station 1035 Outer Park Drive P.O. Box 678 Springfield,IL 62704 Clinton,IL 61727 Joseph V. Sipok Larry Wigley Director - Licensing Manager Nuclear Station Clinton Power Station Engineering Department P.O. Box 678 Clinton Power Station Mail Code Vg20 P.O. Box 678 Clinton,IL 61727 Clinton,IL 61727 Resident inspector U.S. Nuclear Regulatory Commission RR#3, Box 22g A Clinton,IL 61727 R. T. Hill Licensing Services Manager General Electric Company 175 Curtner Avenue, M/C 481 San Jose, CA g5125 Regional Administrator, Region ill U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle,IL 60532 4351 Chairman of DeWitt County c/o County Clerk's Office DeWitt County Courthouse Cl:nton,IL 61727 J. W. Blattner Project Manager Sergent & Lundy Engineers 65 East Monroe Street Chicago,IL 60603

DISTRIBUTION FOR

SUMMARY

OF JANUARY 27,1998, MEETING WITH ILLINOIS POWER COMPANY Hard Conv w/atta f Docket File PD lil "J Reading PUBLIC GGrant, Rlli JHopkins Hard Conv w/Att i  !

OGC ACRS E mail w/Att 1 SCollins (SJC1) ,

, FMiraglia (FJM) 1 THiltz BBoger EAdensam (EGA1)

RSavio Dross (SLM3)

OChopra -

JLazevnick JCalvo l .

l

MEETING ATTENDEES l

j NRC AND lLLINOIS POWER COMPANY l

DISCUSSION OF DEGRADED VOLTAGE ,

l 1

JANUARY 27,1998 '

r NflQ J. Hopkins J. Calvo O. Chopra J. Larevnick lilinois Power comnany ASEA BROWN BOVERI R; Langley D. Osbom P. Telthorst i J. Ray L. Krueger J. Sipok T. Elwood H. Estrada Duke Encinaarina (consultant to Illinois Power Company)

J. Jones R. Sharpe .

T. Poolos R. Daniels '

Attachment 1

MEETING ATTENDEES NRC AND ILLINOIS POWER COMPANY DISCUSSION OF DEGRADED VOL T. AGE JANUARY 27,1998 a

i h

NRC J Hopkins J. Calvo '

}

O. Chopra I J. Lazevnick Illinois Power Comoany AGEA BROWN BOVERI R. Lant,tey D. Osborn l

P. Telthorst J. Rav L. Krueger J. S!pek l T. Elwood H. Estrada Duke Engineering (consultant to Illinois Power Compariy)

J. Jones R. Sharpe T. Peoios R. Daniels Anschment 1 l

i l

Ni Clinton Power Station Presentation to the NRC 3, on the p

Degraded Grid Voltage Project January 27,1998 Purpose of Meeting

• Describe problems associated with projected offsite source voltages Explain the modifications that v/ill solve the problems

~ '

isttachment 2

u

.I r .

A Agenda a Existing design

• Definitions

. 345 & 138 kV offsite voltages ,

• Modifications

• Control and protection strategy

• Conclusions k.

nmm s M= Existing Design 1997 'O-

. 1 1 #- --

v.7 a.. . ., x x e. .

7 4 W WWMB to 4 W W,.4 95 g

22 WA assensten H NVA

= ._ - -

• 1? *

• • • • • * "E ** * *f **

i.... 6 s- s ...

.n., . .. .

e El 6 GDS C 800a, GWF M 1

1/27M 4

Definitions Minimum operable offsite voltage (V345KV MIN OP, Y138KV MIN oP) *

- Will stan and operate AC safety related equipment

- Will reset the degraded grid relay (DGR)

(second level relay)

• Safety buses will stay connected to offsite source

- Based on LOCA and uni'. trip loading Il27f08 5 Defmitions Minimum expected offsite voltage (Y345KV MIN EXP,Y138KV MIN EXP) iS based on

- CPS offline

- LOCA and unit trip loads at CPS

- Major unit offline or majorline out

- Minimum of summer / winter system voltages smm s p e A

Liinton Power Station ,

Presentation to the NRC on the Degraded Grid Voltage Project January 27,1998 i

l Purpose of Meeting .

Describe problems associatcd with projected'offsite source voltages Explain the modifications that will solve the problems 1 5 /98 2 S

A,

Agenda-

• Existing design

• Definitions

• 345 & 138 kV offsite voltages

• Modifications

• Control and protection strategy

• Conclusions ICM8 3 l

l

."-- - Existing Design 1997 "%

v 1 1w

- n

- 3 . r_ A A .::=.. , . .

e te n M 4 en n a.

-g

~

.EET T e - =a

1. 8 WYA w1Tw

• a.r **

• a.n ma s i -s s

,,  !..Mt .  !. .". . . I. .M t .

IP NVA l@l98 4

t Definitions

. Minimum operable offsite voltage (V343y,y uis op, Vi3ggy uis op) :

- Will start and operate AC safety related equipment

- Will reset the degraded grid relay (DGR)

(second level relay)

• Safety buses will stay connected to offsite source

- Based on LOCA and unit trip loading imm 3 Definitions Minimum expected offsite voltage-

-(V 343gy mis exp, V issKV MIN EXP) iS based On

- CPS off line

- LOCA and unit trip loads at CPS

- Major unit offline or major line out

- Minimum of summer / winter system voltages IQ7M 6 v ' s _ _ . _ _ _ _ _ _ . _ . . _ . _ _ _

0

' Definitions Maximum operable offsite voltage (V345KV MAX OP,V338gy uix op) :

- Will operate safety related equipment at voltages 5 maximum voltage rating

,- Based on minimum plant loading .

Maximum expected offsite voltage (V345KV MAX EXP,V 33 sgv xxx exp)

- Based on ANSI rating standard

= Vuskv-exp ioss

l.

• V sskv i max exp. io5s v-smM 1 l

Design Requirement

- Undervoltage V345KV MIN EXP 2V345KVMWOP + Margin V 138KV MIN EXP 2Y138KV MN OP + Margin Overvoltage V 345KV MAX EXP $Y345KVMAXOP + Margin V i38Kv MAX EXP IY138KV MAX OP + Margin imm .

k' e _

t 345 kV Voltages, No Modifications

. . . . . . . . . . . . . . . . . . . . . . v,,, ,, ,,, .10s %

Vuuv mx o, =103%

Vuuv me, =101%

100 % -

E-95 %

Vuay m gx, 90% . . . . . . . .

97 98 99 . 0 1 2 3 4 5 6 7 Year im/w e l

CPS Voltages, V345xv (No Modifications,2007) s im/98 10

s i

~~ Ex.isting Design 1997 ~~

.~ .< . 1 1,::;~a 4

v.7

• • --- . rx ,

1 A .: c=. , ..

o

\L/

. .; m. 1 .

,y u -

nm  ? ?_  :,

1 anuj

,.........................w.n~

! h h h

~~

una imM 11 138 kV Voltages, No Modifications V my ex exp=106%

i Vi my mx c,=103%

100 % -

V m y uno ,=06 % .

i

> M%- 90 %

I- V, vungxp 80 %

MMM 4 1 2 3 4 5 6 7 Year imm 12 L-_--- w-

l

\

CPS Voltages, Vi33 gy (No Modifications,2007) 1m% 13 4

Problem Summary I

- Offsite voltages too low on 345 and 138 kV

- Steady state

- Motor start

. Offsite voltages too high on 345 and 138 kV Overvoltage & undervoltage problem imM 14 w - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ - -_

1998 Modifications

• Add a +28.5/-14 MVAR static var compensator-(SVC) to the RAT

• Add a +28.5/-14 MVAR SVC to the ERAT

• Replace 9 non regulating 480/120 volt transformers with regulating transformers im. i, i

Modifications Under Consideration (>1998)

• Replacement of the fixed ratio ERAT with an LTC ERAT

• Replacement of the fixed ratio RAT with an LTC RAT IG/98 16 j

1 mg

l--

t Syc Components 0 F D- 2 g . - TO 7RANSFORMR BUSES

......................................,...... ..............................3.....3

,) $2-$vC 1 .

) $2 SVC 2 fh SCR 1 h SCR 2 m

} q Q s v THYRISTOR Y

$ WITCH THYRISTOR STH &7TH CAPACITUR (TMROLLED HARMulNC (TSC) REACTOR FILTER 21MVAR (TCR) 7.5 MVAR (CAP)

JI.S MYAR

....au......................................................................>

Static Var Compensator (SVC)

Manufacturer. Asea Brown Boveri(ABB)

Technology used all over the world 745 kV to 2.4 kV systems installed ( CPS 4.16 kV) 1-2 MVAR to 100s MVAR installed (CPS 28.5 MVAR)

I/27!98 18

_- _ _ _ _ - _ _ _ _ - _ _ \

Static Var Compensator (SVC)

Installed in harsh electrical environments

- Arc furnaces

- Rolling mills

- Mines Minimal harmonics generated

• No impact on short circuit interrupting duty

,mn8 ,,

g SVC Modification

=- =.

1 i :.:::';.

.=:::::::.7 r- ~. -.. , A . A,~

, =, .. ,. .

... ) ....

) g

t. w 22 MVA }

8 . :- t . s-f m,,.

+28/.14 MVAR I. NVA I l

. am

.2* " a =

!.. . . ).. .

-_._ ~  :

$........, f' . 6 ,

. . . . t. . . .

,. _ A l CSS M w .

1 CPS Voltages, V345xv With SVC,2007 1

I l

sma . v CPS Voltages, V ss i xv Wit.h SVC Limit,2001 e

t e

E P b

t E&M N l

i 1

0 m -

Maximum Voltages With SVC Modifications 345 &l38 IN system maximum design voltageis 105%

With the 345 &l38 kV system at 105% all equipment voltages are 5 maximum rated voltage

- RAT: 2007

- ERAT: 2001 smm 2>

i Svc Control 1

/

,0PM'.iCLOSE.. J )

$25VC1i l

omorr . . . . . . . .

..................05.jcost DC5 ""E '

l...... 2-SVC 2 t& v t4 SCR.I V,,,, t se SCR-2 Iric + 1xa.Iw IFfTERLOCKS HF 7.5 MVAR (CAP)

(TSC) 21MVAR (TCR) 21.3 MVAR ICM8 24

~w.

SVC DCS

. Controls the systern voltage by

- Con'trols firing angle for TSC (on or off)  ;

- Controls firing angle for TCR (modulating)

Open and closes breakers 52-SCV-1 and 52-SCV-2 Trips the SVC by:

- Tripping breakers 52-SVC-1 and 52-SVC-1 .:

- Turning off SCR-1 and SCR-2 ImM 25 DCS Trips for TSC -

. Unbalance line currents i

a SCR-1 overcurrent Unbalance capacitor current Loss of pulse to SCR-1 imm u 1

DCS Trips for TCR j

Unbalance line currents SCR-2 overcurrent Loss of pulse to SCR-2 1/27/98 27

-DCS Trips for the Filter Bank Filter resistor open circuit Filter resistor over load

)

1/27/98 23 h

y , ____;

-DCS Trips for SVC Input Voltage & Current

• Time delay overvoltage

- Coordinated with safety equipment ratings

• Time delay undervoltage

- Coordinated with DGR & LOV

• SVC overcurrent and short circuit im. 3 l

SVC Interlocks

• Freeze RAT SVC

- RAT to ERAT connection

- RAT to UAT connection

- EDG paralleled to the RAT

• Freeze the ERAT SVC

- RAT to ERAT connection

- EDG paralleled to ERAT 1/27FA 30 e

4

(

' sue.um .

SVC Modification -

s: -  :=

- -- 1 1,t:.:::::.

_3~ A A .:ra.

as.a.

= mv g

9_ -.

m p ,- p ... - ._

+28/14 MVAR

,9 TC1T'"'

,.T.......

..__ 1.. . ..-.. F..

-i -

4 ... .. ........., .. ........, .. ...

e .! .!

_-lg'r Tit.

.. '. Jt*J. , ' ?*.1 ,

IfDM 31 I'

I L Protection System Trips Over voltage Under voltage

• Overload Harmonic Phase unbalance Short circuit - -

t/M M 32

4 Svc Control & Protection PROTECTION SYSTEM A j OVERVOLTAGE UNDERVOLTAGE I rv 7

i OVERLOAD HARMONICS V gv TRIP PHASE UNBALANCE j8I1TMSI....

S2 SVC4li )% SHORT CIRCUTT Omm .......... ...............j ....ott.NfLOSE x --

Oc, cca v , t ....g fl

,,.,Yc.,

f -

"i TRIP p

\y l "a = {

SCR l \ Vee I sw SCf: . I l $ $

\ Incelwn*Iw -

l

---

f---l TRIP uMv1C.

U I

' # ' OVERVOLTAGE H rv 21 MVAR l OVERLOAD LTAGE HARMONICS '""""V,g imM PROTECTION SYSTEM B PHASE LNBALANCE 33 SHORT CIRCUIT Protection System Design Independent of DCS Two protection devices

\'

Each device powered by a separate battery Trips the SVC by

- Tripping breakers 52-SVC-1 and 52-SVC-1

- Turning off SCR-1 and SCR-2 Imm u

Impact of Tripping SVC

= Plant on line, BOP loads on UAT,

- Main generator will control voltage

- Safety buses should stay connected to offsite source l

- Offsite source associated with SVC may become inoperable

- Operator can transfer to other source

- No plant transient imM 35 Impact of Tripping SVC Plant offline

- The offsite source associated with the SVC may become inoperable

- The DGR may be required to operate nmm u

1 Conclusions

• SVC expands operable offsite source voltage to:

- Vusky. 95% to 105%

- Vnggy. 90% to 105%

• SVC controls 4.16 kV bus voltage at -100%

over total offsite source range for steady state conditions IC7M 37 Conclusions i

SVC maintains the voltage ;t 75% during motor start -

• SVC DCS and protection system minimize impact of SVC failures on safety and non safety equipment .

SVC tripping has minimal impact with plant online SVC best technical solution IC7M 38

- _ _ - - _ - _ _ _ _ _ _ _ _ - . - _ _ _ - - _ - .