ML18100A541

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Discusses Plant Mgt Meeting W/Util on 930718 Re Insp Repts 50-272/93-81 & 50-311/93-81.Topics Discussed Included Numerous Rod Control Sys Failures Which Occurred During May & June 1993.Attendees Listed in Encl 1
ML18100A541
Person / Time
Site: Salem  
Issue date: 08/11/1993
From: Hodges M
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To: Miltenberger S
Public Service Enterprise Group
References
NUDOCS 9308170146
Download: ML18100A541 (56)
v • d • e


See also: IR 05000272/1993081

Text

'

Docket Nos. 50-272

50-311

Mr. Steven E. Miltenberger

Vice President and Chief Nuclear Officer

Public Service Electric and Gas Company

P.O. Box 236

Hancocks Bridge, NJ 08038

Dear Mr. Miltenberger:

AUG 11 1993

SUBJECT:

SALEM MANAGEMENT MEETING

On July 18, 1993, a management meeting was held with you and other representatives of

Public Service Electric and Gas and the staff of the NRC. The topic discussed at the

meeting was the numerous rod control system failures which occurred during May and

June 1993, and were the subject of an Augmented Team Inspection. Enclosed is a list of the

meeting attendees [Enclosure 1]. Also enclosed are the handouts you provided at the meeting

[Enclosure 2].

During the meeting, your presentation included: 1) a technical assessment of the rod control

system malfunctions and their causes, 2) a safety assessment of the malfunctions, 3) the

assessment provided by your Significant Event Response Team, and 4) corrective actions

taken as a result of these malfunctions.

The NRC Augmented Inspection Team performed an independent review of the rod control

system problems and the results of this inspection are documented in NRC Combined

Inspection Report 50-272/93-81; 50-311/93-81.

In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," its enclosures will be

placed in the NRC Public Document Room. No reply to this letter is required .

9308170146

  • PDR

ADOCK

G

930811

05000272

PDR

OFFICIAL RECORD COPY

A:SALEMMTG.618

Mr. Steven E. Miltenberger

2

AUG 11 1993

Your cooperation with us is appreciated.

Enclosures:

Sincerely,

Original Signed By.

Marvin W. Hodges

Marvin W. Hodges, Director

Division of Reactor Safety

1. PS&EG Management Meeting List of Attendees, July 18, 1993

2. PSE&G Meeting Handouts

cc w/encls:

J. J. Hagan, Vice President, Nuclear Operations

C. Schaefer, External Operations - Nuclear, Delmarva Power & Light Co.

C. Vondra, General Manager - Salem Operations

R. Hovey, General Manager - Hope Creek Operations

F. Thomson, Manager, Licensing and Regulation

R. Swanson, General Manager - QA and Nuclear Safety Review

J. Robb, Director, Joint Owner Affairs

A. Tapert, Program Administrator

R. Fryling, Jr., Esquire

M. Wetterhahn, Esquire

J. Isabella, Director, Generation Projects Department,

Atlantic Electric Company

Consumer Advocate, Office of Consumer Advocate

William Conklin, Public Safety Consultant, Lower Alloways Creek Township

K. Abraham, PAO (2)

Public Document Room (PDR)

Local Public Document Room (LPDR)

Nuclear Safety Information Center (NSIC)

NRC Resident Inspector

State of New Jersey

OFFICIAL RECORD COPY

A:SALEMMTG.618

/

Mr. Steven E. Miltenberger

bee w/encls:

Region I Docket Room (with concurrences)

DRS Files (2)

bee w/o encls: (Via E-Mail)

R. Cooper, DRP

J. Durr, DRS

C. Miller, DRS

E. Wenzinger, DRP

J. White, DRP

J. Stone, NRR

D. Wheeler, OEDO

M. Boyle, PDI-2, NRR

T. Martin, RA

W. Kane, DRA

RI:DRS

Sc~gcb

RI: DRS

3

1;y193

~ ~/fc,/93

AUG 111993

-RI:DRS

H~~

tf///93

OFFICIAL RECORD COPY

A:SALEMMTG.618

PSE&G:

S. Miltenberger

S. La Bruna

J. Hagan

C. Vondra

F. Thomson

W. Stewart

L. Miller

L. Rajkowski

E. Robinson

T. Ross

D. Best

H. Onorato

NRC:

T. Martin

W. Kane

R. Cooper

E. Imbro

E. Wenzinger

J. White

B. McDermott

W. Maier

T. Johnson

S.Barr

H.Garg

D. Screnci

J. Stone

P. Patniak

R. Skokowski

W. Ruland

L. Scholl

M. La7.arowitz

J. Calvo

ENCWSURE1

LIST OF ATTENDEFS

Vice President and Chief Nuclear Officer

Vice President - Nuclear Engineering

Vice President - Nuclear Operations

General Manager - Salem

Manager - Licensing and Regulation

Media Relations Representative

General Manager - Nuclear Operations Support

Supervising Engineer - Instrumentation and Controls

Principal Training Supervisor

Senior Staff Engineer

Systems Engineer

Licensing Engineer

Regional Administrator

Deputy Regional Administrator

Director, Division of Radiation Safety and Safeguards

Deputy Director, Division of Reactor Safety

Chief, Projects Branch 2, DRP

Chief, Reactor Projects Section 2A, DRP

Reactor Engineer, DRP

Operations Engineer, DRS

Senior Resident Inspector, DRP

Resident Inspector, DRP

Senior Electrical Engineer, NRR

Public Affairs Officer, ORA

Salem Project Manager, NRR

Reactor Inspector, DRS

Reactor Engineer, DRS

Chief, Electrical Section, DRS

Reactor Engineer, DRP

Reactor Engineer, DRS

Assistant Director for Region I Reactors, NRR

Enclosure 1

Other Organizations

R. Oakes

P. Duca

T. Robb

M. Beaumont

P. Milford

2

Salem Site Representative - Atlantic Electric

Salem Site Representative - Delmarva Power

Director - Joint Owners Affairs

Manager - Rockville Licensing (Westinghouse)

Reporter - Wilmington News Journal

-

ENCLOSURE2

-ps~G

Public service

8

Electric and Gas

Company

SALEM UNIT 2

ROD CONTROL SYSTEM

JUNE 18, 1993

SALEM

GENERA TING STATION

-

D

e

I * * I

111 II *

II 111 I

fl_.

..

SALEM UNIT 2

ROD CONTROL SYSTEM

AGENDA

INTRODUCTION

S. E. MILTENBERGER

MEETING OBJECTIVES

S. E. MILTENBERGER

CURRENT PLANT STATUS

S. E. MILTENBERGER

SYSTEM OVERVIEW

D.BEST

CHRONOLOGICAL SUMMARY

C.A.VONDRA

TECHNICAL ASSESSMENT OF

L. J. RAJKOWSKI

MALFUNCTIONS

SAFETY ASSESSMENT

F. X. THOMSON

SERT ASSESSMENT

L. K. MILLER

CORRECTIVE MEASURES

C.A.VONDRA

CONCLUSIONS

S. E. MILTENBERGER

e tf

13MM3-2

SALEM UNIT 2

ROD CONTROL SYSTEM

MEETING OBJECTIVES

e PROVIDE THE RESULTS OF PSE&G'S ASSESSMENT OF THE

ROD CONTROL SYSTEM MALFUNCTIONS

e IDENTIFY CORRECTIVE MEASURES

e PROVIDE ASSURANCE FOR CONTINUED SAFE OPERATION

OF UNIT 2

e OBTAIN CONCURRENCE FOR ACTIONS NEEDED TO CLOSE

OUT CONFIRMATORY ACTION LETTER

e *.

SALEM UNIT 2

ROD CONTROL SYSTEM

CURRENT PLANT STATUS

SALEM UNIT 1

  • MODE 3

e NORMAL OPERATING TEMPERATURE AND PRESSURE

e RCS - DIODE SUPPRESSION DCP INSTALLED FOR ALL

GROUP COUNTERS

SALEM UNIT 2

  • MODE3
  • NORMAL OPERATING TEMPERATURE AND PRESSURE

e UNIT ON HOLD FOR STARTUP PENDING:

- RCS LOGIC CABINET CARD REPLACEMENT

e COMPLETION OF SHORT TERM CORRECTIVE ACTIONS

.r

SALEM UNIT 2

ROD CONTROL SYSTEM

SYSTEM OVERVIEW

  • PURPOSE

- POSITION CONTROL RODS IN.RESPONSE TO DEMANDS

FOR MOTION FROM EITHER THE REACTOR OPERATOR

OR THE ROD CONTROL SYSTEM

e INTERFACES

- CONTROL BOARD

- PROCESS CONTROL

e BLOCK DIAGRAM

- LOGIC CABINET

- POWER CABINET

- DC HOLD CABINET

- RCS MG AND TRIP BREAKERS

- ROD GROUP ARRANGEMENT

e LOGIC CABINET BLOCK DIAGRAM

- SYSTEM OPERATION

  • CROM

e CURRENT TRACES

13MM3-3

..*

~

-

  • *

..

SYSTEM INTERFACE BLOCK DIAGRAM

Annunciator

Panel

-

-

\\~ \\

Co~trol /

/

\\

Board

~ 0

~

Soeed-

Direction

RIL

Alarm

~ '

TH

---

Alanna

-

--

Logic

Cabinet

0

'

Group

Step a

Current

Commands

Group

Select

Bank

Steps

Alarms

4-

~ ,

Plant Computer *

Tc

- ' ' '

Proceaa

Pimp ...

Rack

Control

Bank Steps

NIS-

j *

a*nana.002

--

..

--

Power Cabinet

( 1 of 5)

D

' '

j l

I

I

DC

-

Hold

Cabinet

CROM

Litt

Current

Movable

..::..

Current -

Stationary

Current

I

- - - - -

Control

P-A

Converter ~ Bank

i-.----

voe

..

..

BASIC SYSTEM BLOCK DIAGRAM

'~* .

480VAC =:

60HZ

f1c

Speed

and

Direction

228l23111.001

Motor

BKRS

Logic

Cabinet

D

Motor

Generator

( 1 of 2)

Gen

BKRS

Main 120VAC

Current Commands

Group Select

260 VAC

Reactor

Trip Bkrs

Power Cabinet

( 1 of 5)

D

CROM

Reactor

Protection

Trip Signals

Lift

Current

Movable

Current

I..____.._ ____________ ~ ' '

Auxiliary

120VAC

260VAC 3/J

DC

Hold

Cabinet

- - -

Control

P-A

L--~~~---t~ Converter

Bank Steps

- - -

125 voe

or

10 voe

Stationary

Current

Control

Bank voe

"l . *

~

ROD CONTRO*L SYSTEM

Bl°'* Qlaaram

Current

Power Cabinet

1AC

Bank Selector r---1

Logic

Cabinet

I

Command

Group

I I

  • Gr 1, CA (2)(4)

~ar 1, cc t*>

---*Gr 1, SA (4)

Rod Out

--

siO.,

Current

Command

Swhch

  • Out

.-----. ~= :

I

      • I I

I

In .

I

~= I

I 0Ho1c11

I Auto...

I I -

I

L..-. *--' ~.na---t,~ ... --....

L---.J

I Current

Command

I

-

Control Bo*rd

Auto In

a..;.;A*u-lo;,,.;Ouiiiiiiiimiiit __ R-1:1!

Speed

Stoo

I

I

.. -..

. . -

... _.,... __ ,...

I **--

Speed

  • -

Current

Command

Current

.......... -- Command

~ I

Individual

Bank

Select

u 1 Bank Selector Switch

---

Proce** Rack

  • MAN, CA, CB, CC, or CD Position
    • SA SB SC or SD Poaltlon
      • MAN, CA. c'e, cc. co. SA, SB, SC, or SD

Select

PowerCab~et2AC *

Group

Select

I

I I

-.ar 2, CA (2)(4)

  • Gr 2, CC (4)

---*Gr 2 1 SA (4)

Power Cabinet 180

Group

I I

-.ar 1. ce (4)(2)

Select

  • Gr I, CD(*)

I

_ __.__.--Gr I, SB (4)

Power Cabinet 280

I

Oroup

Select

  • Or 2. CB (4)(2)

I I

,..Gr 2. co (5)

~Or 2, SB (4)

---

Power Cabinet SCD

I

Group

Select

I I

.. sc (4)

ROD CONTROL SYSTEM

LOGIC CABINET BLOCK DIAGRAM

M81ftAC'"-

1120 VAC _, HZI

Awl .....

AC'"-

,,..,._,---~~L!!!!!!.!~~--1-~

-llllll

, ............ ~......::.:.:~==:w:.:=====-~--1:::=~ ..... ,.,....~~-1

1* t002-t211. t/T23'71.024

.....

c.-r

IA.U

..................

OOIAC

OOllO

-

}*~OI

a;;.;.;;:;..;;;.;=~ ao.d

Tof'IMI

~

JoPIA

eon....

10280

p-

CllblMI

CONTROL ROD DRIVE MECHANISM

(~

\\ ""' ~

Rod Trave1~m

Housing

~;;

  • ~

.

I

Disconnect

Button

Pressure Vessel

Housing Assembly

Stationary Gripper--..

Coil Stack

  • - ..

. ..._."

I

I

. _ ___,

~

~

Electrical

Lead Tube

Movable Gripper

Latch Assembly

Stationary Gripper

Latch Assembly

--Connection to

RCCA Spider

Assembly

LATCHING

1

.

  • '*'{~

MECHANISM

~.:

Lift Coil

Movable

Coll

Flux Ring

Stationary

Coll

Drive Rod

' 'f IWlll9fW* I

Guide Tube

Lift Pole

Flux Ring

Lift Armature

Movable Gripper

Movable Gripper

Armature

(Shown Open)

Stationary

Pole

Stationary

Gripper

Armature

Stationary Gripper

  • *

..

, Normal Oscillograph Trace

Lill Pole

Closed

I

MG Pole Closed & --11-...

MG Laich In

Lo*d Transfer

SG Pole Open &

SQ l*lch Out

Lill Pole Open

SG Pole Closed &

SG Latch In

MG Pole Open &

MG Laich Oul

Lill Pole

Closed

g

>

3 1 i

~

r

C>

>

>

3

3

1

-0 ..

...

...

I

II

--Hold-

MG Pole Closed &

MG Latch In

Load Transler

SG Pole Closed &

SG Laich Oul

Lill Pole Closed

SG Pole Closed &

SG Latch In

MG Pole Open &

MG Laich Out

Lill Pole Open

-MG Pole Closed &

MG Laich in

V>

0 c

r a.

(/)

C>

>

3

u

CD ...

CD

Cl>

r ::

>

3

~

...

Cl

""

-Holdl

~

r

a.

.,

DI

~

CJ)

Ci

'O

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

SEVENTH REFUELING OUTAGE MAINTENANCE AND TESTING

e WESTINGHOUSE CARD TESTING SERVICES CONTRACTED

BY PSE&G

- RELIABILITY IMPROVEMENTS

-

VISUAL INSPECTION AND LOGIC CARD TESTING

- REPAIR/REPLACEMENT CRITERIA

- LOGIC SYSTEM DYNAMIC TESTING

e MAY 24, 1993

- MG SET BALANCING AND DYNAMIC TESTING

- IRPI CALIBRATIONS

A CONTROL BANK A GROUP 2 FAILS TO MOVE -

URGENT FAILURE ALARM

-

A CONTROL BANK B STEP COUNTERS FAILURE

- REPAIRED CARDS AND REPLACED 2 STEP COUNTEh&'

- PERFORMED POST MAINTENANCE FUNCTIONAL TESTS

- IRPI CALS AND ROD DROPS COMPLETED ..

SATISFACTORY

- ROD CONTROL SYSTEM READY FOR PLANT STARTUP

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 25, 1993

e OPERATIONS PERFORMED SURVEILLANCE TEST

e COMMENCED STARTUP

e CONTROL BANK C GROUP 1 STOPS ADVANCING AT 31

STEPS

e REINSERTED RODS IN REVERSE ORDER

e MALFUNCTIONS FOUND THAT WERE NOT RELATED TO

BANK C GROUP 1 COUNTER

e INITIATED TROUBLESHOOTING VIA CARD REPLACEMENT

e DISCOVERED SHORTED DIODES ON A CARD TESTED

SATISFACTORY

e ATTRIBUTED OTHER FAILURES TO CARD WITH SHORTED

DIODES

e REPAIRED OR REPLACED AFFECTED CARDS

e PERFORMED FUNCTIONAL RETEST OF LOGIC AND

COUNTERS

  • - "

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 27, 1993

e COMMENCED STARTUP

e SHUTDOWN BANK A WITHDRAWN TO 20 STEPS - NO

INDICATION ON IRPI

- DURING INSERTION OF SHUTDOWN BANK A - 1 SA3

INDICATES WITHDRAWAL TO 15 STEPS

- l&C CONFIRMS IRPI FOR 1 SA3 AT 15 STEPS

- STATIONARY GRIPPER FUSES PULLED TO INSERT

1SA3

  • LOGIC CABINET TROUBLESHOOTING IDENTIFIED 2

FAILED CARDS

e PERFORMED CURRENT ORDER TRACES AND CAPTURED

INVALID CURRENT TRACES

e REPLACED FAILED CARDS

  • ATTRIBUTED APPARENT FAILURE TO SELF-INDUCED

PROBLEMS DUE TO TROUBLESHOOTING OF MAY 26

e SEGREGATED CARD FOR FURTHER ROOT CAUSE

'\\NALYSIS

83MM3-7

t:.

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 27, 1993 (CONTINUED)

e CONSULTATION WITH VENDOR REGARDING 1SA3 ROD

MOTION

  • VENDOR INDICATED ROD RESPONSE NOT TOTALLY

UNEXPECTED FOR THIS CONDITION

  • VENDOR INDICATED CROM WAS NOT DAMAGED BY

THIS OCCURRENCE

e STATUS MEETING BETWEEN OPERATIONS,

MAINTENANCE, SYSTEM ENGINEERING, E&PB AND

VENDOR

113MM3-7A _

~

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 28, 1993

e COMMENCED NORMAL STARTUP WITH ROD CONTROL

SYSTEM

e SHUTDOWN BANKS AND CONTROL BANKS

WITHDRAWN - BORON DILUTION TO CRITICALITY IN

PROGRESS

- CONTROL BANK C GROUP 1 RODS DROPPED

- MANUAL REACTOR TRIP INITIATED

  • SERT CONVENED AND CHARTERED TO INVESTIGATE

PROBLEMS WITH ROD CONTROL SYSTEM AND

STARTUP DECISION PROCESS

e TROUBLESHOOTING IDENTIFIES BAD CARD IN THE

POWER CABINET

e DECISION TO PERFORM ADDITIONAL CARD TESTING

- 100 VOLT POWER SUPPLY FUSES.BLOW

e FIND PROBLEMS IN ADDITIONAL LOGIC CARDS

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 28, 1993 (CONTINUED)

e LINE MANAGEMENT PERFORMS EVENT ANALYSIS

- DETERMINES BLOWN POWER SUPPLY FUSES WERE

APPARENTLY SELF-INDUCED

e WESTINGHOUSE PROVIDES ADDITIONAL TECHNICAL

SUPPORT

e REPAIRED NUMEROUS CARDS AND REPLACED 15 VOLT

POWER SUPPLY AUCTIONEERING DIODE

e FULL CABINET TESTING TO VERIFY COUNTERS AND

CURRENT TRACES

- CONNECTED CURRENT TRACE MONITORS FOR EACH

BANK

e PERFORMED PRE-STARTUP FUNCTIONAL TESTING

- EACH ROD BANK PULLED TO 30 STEPS, INSERTED TO

-" -

  • 20 STEPS, MAINTAINED AT 20 STEPS FOR ONE HOUR

THEN INSERTED

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF MAY 28, 1993 (CONTINUED)

e PSE&G SENIOR MANAGEMENT CONTACTED

WESTINGHOUSE SENIOR MANAGEMENT TO SOLICIT ANY

OTHER TESTING OR CHANGE OUTS THAT SHOULD BE

DONE

DETERMINED NO ADDITIONAL ACTIONS SHOULD BE

TAKEN

e DECISION TO RESTART PLANT, BASED ON SORC REVIEW *.

SERT FINDINGS, CONSULTATION WITH VENDOR AND

SENIOR MANAGEMENT REVIEW

I

I

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF JUNE 2, 1993

13MM3-10

e OPERATIONS SURVEILLANCE PERFORMED -

SATISFACTORY

e COMMENCED STARTUP .

e ROD CONTROL SYSTEM OPERATES SATISFACTORILY -

ALL SHUTDOWN AND CONTROL BANKS WITHDRAWN

e IDENTIFY P/A CONVERTER PROBLEM

e DECISION TO SHUTDOWN UNIT 2 TO MAKE REPAIR

  • TROUBLESHOOTING IDENTIFIES FAUL TY DATA LOGGING

CARD

e ATTRIBUTED TO TROUBLESHOOTING

e OPERATIONS FUNCTIONAL RETEST PERFORMED -

SATISFACTORY

e SUCCESSFUL OPERATION OF ROD CONTROL SYSTEM

DURING STARTUP AND SHUTDOWN PROVIDED

ASSURANCE OF SYSTEM RELIABILITY

83MM3-11

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

STARTUP OF JUNE 3, 1993

e COMMENCED STARTUP

e ROD CONTROL SYSTEM PERFORMS SATISFACTORILY -

REACTOR CRITICAL

e NRC REGIONAL INSPECTOR ARRIVES ON SITE

SALEM UNIT 2

ROD CONTROL SYSTEM

CHRONOLOGICAL SUMMARY

JUNE 4, 1993

e REACTOR PHYSICS TESTING IN PROGRESS

e SINGLE FAILURE HYPOTHESIS PRESENTED

e WESTINGHOUSE INITIAL REACTION a NOT PLAUSIBLE (3:00

PM)

e WESTINGHOUSE ADMITS SINGLE FAILURE THEORY IS

PLAUSIBLE (4:30 PM)

e PSE&G DECISION TO PLACE UNIT IN MODE 3

e ALL CONTROL AND SHUTDOWN BANKS INSERTED

e ONE HOUR REPORT IN ACCORDANCE WITH 10CFR50.72

e ROD CONTROL SYSTEM DE-ENERGIZED

e TECHNICAL RESPONSE TEAM FORMED

JUNE 5, 1993

e AIT ARRIVES ON SITE

  • - "

......

13MM3-17

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

e FORMED ROOT CAUSE ASSESSMENT TEAM

- TECHNICAL FACT FINDING

- ENGINEERING ANALYSIS

- REPLICATION TESTING

- COMPONENT EXAMINATION BY MANUFACTURERS

- DETERMINE FAILURE MECHANISMS/ROOT CAUSE

- PROVIDE TECHNICAL INPUT TO SERT

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

TECHNICAL FACT FINDING

13MM3-111

e DEVELOPED TROUBLE SHOOTING CHRONOLOGY. (3/17 -

6/4)

e DEVELOPED COMPONENT FAILURE LIST ( * 30)

e REVIEWED REFUELING OUT AGE DESIGN CHANGES

- EQUIVALENT COUNTER REPLACEMENT

- POWER CABINET POWER SUPPLY MODIFICATIONS

e

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

ENGINEERING ANALYSIS

e EVALUATED SINGLE FAILURE

- DUPLICATED CURRENT TRACES THROUGH

ENGINEERING ANALYSIS

- INVESTIGATED SHUTDOWN BANK A CROM

RESPONSE

e ASSESSMENT OF FAILURES

-

ANALYZED COMPONENT FAILURES AND REPAIRS

- EVALUATED SYSTEM POWER SUPPLIES

- EVALUATED WESTINGHOUSE TESTER

- DETERMINED COMPONENT FAILURE MECHANISMS

- DETERMINED PROBABLE ROOT CAUSES

83MM3-111 c .(

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

REPLICATION TESTING

e SIMULA TED SINGLE FAILURE AT NUCLEAR TRAINING

  • CENTER

- SIMULATED COMPONENT FAILURES

- DUPLICATED EXPECTED CURRENT ORDERS AND

TRACES

- DOCUMENTED CROM RESPONSE SIMULATED

FAILURE MECHANISM

e SIMULATED FAILURE MECHANISMS

- CYCLED POWER SUPPLIES

- MONITORED WESTINGHOUSE TESTER FOR

ANOMOLIES

- BENCH TESTED RELAY DRIVER/COUNTER CIRCUITRY

- SIMULATED TROUBLE SHOOTING ERRORS

- MEASURED BACK EMF

113MMS-20 e "'

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

COMPONENT EXAMINATION BY MANUFACTURER

e MOTOROLA

e PHILIPS

e WESTINGHOUSE

13MM3-21

ROD CONTROL SYSTEM

LOGIC CABINET BLOCK DIAGRAM

..... AC,_

11*vAC*Hlt

a...,...

AC,_

..

.......... --~~~l!!!~l:!..~~t=~

-II*

I

, ........... ~_;::.!!~~1:.:==:::.~~-t;;;;;;;;;1~c:ir--~--t

    • 1002-121111T23171.0IZ4

M ...

...

~

......

c,...

..................

GOIAC

caoo*

}*~.

._II

Tol'lenl

~

TOPIA

c_...

Of8J7- 5

r--"

SALEM UNIT2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

COMPONENT EXAMINATION BY MOTOROLA

SUPERVISORY DATA LOGGING

MC 668L NANO GATI; CHIP

  • ONE CHIP PIN (INPUl) SHORT TO GROUND

CAUSE: ELECTRICAL STRESS DEGRADATION OR

ELECTROSTATIC DISCHARGES

  • ONE CHIP PIN 6 AND 8 (OUTPUl) LEAKAGE

CAUSE: ELECTRICAL OVERSTRESS

  • ONE CHIP PIN 8 (OUTPUl) LEAKAGE

CAUSE: ELECTRICAL OVERSTRESS

APPEARS OVERSTRESS CAUSED A SHORT TO THE

SUBSTRATE

SALEM UNIT2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

COMPONENT EXAMINATION BY PHILIPS

RELAY DRIVER

1N4148 BLOCKING DIODE

  • ONE DIODE FOUND SAT

Ir, Vf, AND Vbr MEET SPECIFICATION

  • TWO DIODES FOUND WITH DEGRADED REVERSE

CHARACTERISTICS

(VERY HIGH REVERSE LEAKAGE, PARTIALLY SHORTED)

  • RESULT OF ELECTRICAL OVERSTRESS

ROD CONTROL SYSTEM

LOGIC CABINET BLOCK DIAGRAM

.._AC,_

11*vAC*et11

~

AC,_

.... a::{

....

c.-.

....

....................

IAC

F--------l =*

.......

c...-

Jol'1A

c-

lo ,._

c-..

Normal Oscillograph Trace

Lih Pole

CloMd

I

MG Pole Closed & -11-~

MG Laich In

Load Tran1ler

SO Pole Open &

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SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

COMPONENT EXAMINATION BY WESTINGHOUSE

SLAVE CYCLER DECODER 3359C62 G02/WSN0079

MC 668L - 6951 NANO GATE CHIP

e CHIP 22, PIN 9 HAS 200 OHMS TO GROUND LEAKAGE

THROUGH SUBSTRATE (INSULATION BREAKDOWN)

e CHIP 21, PIN 5 LEAKAGE TO GROUND

2 MICROAMPS AT 10 VOLTS

(SPECIFICATION CALLS FOR 2 MICROAMPS AT 16V)

THE MOST LIKELY CAUSE FOR THIS FAILURE IS A

VOLTAGE TRANSIENT IN EXCESS OF DEVICE

CAPABILITY RESULTING IN OXIDE -BREAKDOWN

$

  • AND THE RESULTANT "SHORT"

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

COMPONENT EXAMINATION BY MOTOROLA

SLAVE CYCLER DECODER NANO GATES

(2) MC660L, ( 1) MC662L, (2)MC668L

(1) MC668L CHIP FOUND PIN 1 TO GROUND FAULT

DUE TO ELECTRO STATIC DISCHARGE (ESD)

OTHER MC668L AND BOTH MC660L SAT

(1) MC662L EVIDENCE OF (ESD) DAMAGE THROUGH

MICROSCOPE ANALYSIS

PROCESS:

1.. COMPUTER CHIP TESTER

2. LAB CONFIRMATION (TRACER CURVE TEST)

3. MICROSCOPE ANALYSIS (COLOR VIDEO)

4. SCANNING ELECTRON MICROSCOPE (SEM)

INCLUDING SILICONE ETCHING

..

n * *.

BASIC SYSTEM BLOCK DIAGRAM

480VAC =:

60HZ

pJC

Speed

and

Direction

22* "T23' 1*.00'

Motor

BKRS

Logic

Cabinet

D

Motor

Generator

( 1 of 2)

XFMR

Gen

BKRS

Main 120VAC

Current Commands

Group Select

Auxiliary

120VAC

260VAC 3/J

DC

Hold

Cabinet

Control

-P:-A-

L--~-----1~ Converter

Bank Steps

- - -

260 VAC

Reactor

Trip Bkrs

Power Cabinet

( 1 of 5)

D

' '

125 voe

or

10 voe

CROM

Reactor

Protection

Trip Signals

Lift

Current

Movable

Current

Stationary

Current

Control

Bank voe

. ' BRlt)GE CONTROL CIR'CUIT

Current

Orders{

from

Logic

Cabinet

H7Clt tltt11.0t t

Phaee

Control

Card

'

Error

Sign al

-

--

-

Phase

-

-

Sensing

-

XFMRS

-

Firing

-

-

-

.

Card

-

. --

~ ---*

--

-

I *

-

-1

I

Rff . ' Rz

Regulation

i.-

Card

I

I

-+

Coil Current

Samples

ftg. 2-13

fdc N

--

-

-~

, 7 ,

1 , 1

(

.. ; ..

i

...

-- -

,1 , .,l , , 1, ~ 1

- .. - .. -.. -...

I'* Ii * 1r* ~::

11111

II

1

111

11.

II

I~

11

- - -

- -

-

  • * ...
  • ~ ::
  • * ...

.. .

.. . .. . ..

Half Wave

Thyristor

Bridge

Mechanism

Coils

SALEM UNIT 2

ROD CONTROL SYSTEM

TECHNICAL ASSESSMENT

FAILURE MECHANISMS I ROOT CAUSE SUMMARY

e RELAY DRIVERS/SUPRV. DATA LOGGING

~ PIN CONNECTION FOR SUPPRESSION DIODE

- COUNTERS COIL BACK EMF

  • SLAVE CYCLER DECODER

-

VOLTAGE TRANSIENT ASSOCIATED WITH COUNTER

BACK EMF

-

EXTENSIVE TROUBLE SHOOTING

e SHUTDOWN BANK A CROM RESPONSE

-

COIL TIMING (LIFT AND MOVABLE)

-

FRICTION: DESIGN TOLERANCES AND/OR OXIDES/CRUD

BUILD-UP

e CONTROL BANK C GROUP 1 DROP

- REGULATION BOARD TRACE DEGRADATION

e P/A CONVERTER FAILURE

- SUPERVISORY DATA LOGGING (SOL) FAILURE

-

INCOMPLETE TESTING ON PRIOR REPLACEMENT OF SDL

e STEP COUNTER FAILURE

- MECHANICAL BINDING

SALEM UNIT2

ROD CONTROL SYSTEM

SAFETY ASSESSMENT

  • ASSUMED SINGLE FAILURE CAN RESULT IN SINGLE

ROD WITHDRAWAL

  • UFSAA ACCIDENTS ANALYSIS CONSERVATIVELY

RE-EVALUATED AGAINST CONDITION II CRITERIA

(DN BR 2: 1 .3)

- BASED ON ASYMMETRICAL ROD WITHDRAWAL

- DNBR 2: 1.3 FOR ALL CONDITION II EVENTS EXCEPT

ROD WITHDRAWAL FROM SUBCRITICAL

- STARTUP PROCEDURE MODIFIED TO ADDRESS ROD

WITHDRAWAL FROM SUBCRITICAL

- WILL DILUTE TO CRITICAL WITH CONTROL RODS

WITHDRAWN DURING RESTART

- NO FUEL FAILURES DUE TO ASYMMETRICAL ROD

WITHDRAWAL

- QDC 25 CRITERIA MET

SALEM UNIT2

ROD CONTROL SYSTEM

SAFETY ASSEMENT

  • COMPENSATORY ACTIONS IMPLEMENTED TO PROVIDE

ADDITIONAL ASSURANCE

- STANDING NIGHT ORDER

- ADDITIONAL SURVEILLANCE TESTING

- CURRENT TRACES PRIOR TO RESTART

- DILUTE TO CRITICAL WITH CONTROL RODS OUT

- OPERATOR BRIEFINGS/TRAINING

  • BASED ON CURRENT INFORMATION, USQ ASSUMED

TO EXIST

  • USQ REVIEW REQUEST SUBMITTED TO NRA 8/17/93
  • TEMPORARY LICENSING BASIS CHANGE PENDING

FINAL INDUSTRY RESOLUTION

SALEM UNIT 2

ROD CONTROL SYSTEM

SERT ASSESSMENT

SERT CHARTER - MAY 28, 1993

13MM3-12

e INVESTIGATE ROOT CAUSES FOR ONGOING FULL LENGTH

ROD CONTROL SYSTEM (FRCS) PROBLEMS

e PRUDENCE OF STARTUP DECISIONS

SALEM UNIT 2

ROD CONTROL SYSTEM

SERT OBJECTIVES

e DEVELOP SEQUENCE OF EVENTS/CAUSAL FACTORS

CHART AND IDENTIFY FAILED BARRIERS

SERVICES AND OTHER OUT AGE ACTIVITIES

e ASSESS OPERATOR RESPONSE TO DROPPED RODS AND

ISA3 ANOMALY

e ASSESS MANAGEMENT CONTROL OF

TROUBLESHOOTING

e ASSESS USE OF OPERATING EXPERIENCE AND

ADEQUACY OF PM

c ".

93MM3-13

113MM3-14

SALEM UNIT 2

ROD CONTROL SYSTEM

ADDITIONAL AREAS EXAMINED

e RELAY ROOM VENTILATION

e DESIGN CHANGES

e PROCUREMENT

e SOLDERING

e TRAINING

SALEM UNIT 2

ROD CONTROL SYSTEM

ANALYTICAL TECHNIQUES

ACTIVITIES

e 75 INTERVIEWS

e 1350 DOCUMENTS/RECORDS REVIEWED

e 2400 TEAM HOURS TO DATE

e 18 TEAM MEMBERS - SOME PART-TIME INCLUDING 6

CONTRACTOR PERSONNEL ADDED FOR SPECIFIC

EXPERTISE

-

IECFINIQUEs-------- ------ ------- - --- --------- -- - --------- -- --

-

e EVENT AND CAUSAL FACTOR CHARTING

e HUMAN/EQUIPMENT CAUSAL FACTOR ANALYSIS TO

VALIDATE

STATUS

e PRELIMINARY FINDINGS/CONCLUSIONS DETERMINED

e CORRECTIVE ACTION RECOMMENDATIONS BEING

DEVELOPED

e VALIDATION IN PROCESS

.*- ..

.,_

SALEM UNIT 2

ROD CONTROL SYSTEM

SERT ASSESSMENT

FINDINGS/CONCLUSIONS (PRELIMINARY)

e CONTROL ROOM RESPONSE WAS CONSERVATIVE AND IN ACCORDANCE

WITH *PROCEDURES

e 1 SA3 WAS NOT ASSESSED AS A DESIGN BASIS CONCERN

e CONTROL OF TROUBLESHOOTING WAS LESS THAN EFFECTIVE

e REPETITIVE COMPONENT FAILURES DID NOT INITIATE SEARCH FOR

COMMON FAILURE MODE RESTART DECISIONS WERE MADE WITHOUT

ROOT CAUSE RESOLUTION OF THE REPETITIVE FAILURES

  • SALEM HAS NO HISTORY OF SIGNIFICANT FLRCS FAILURE

e VENDOR SUPPLIED INFORMATION DID NOT DENOTE COIL RES!3TANCE

DIFFERENCES FOR SAME MODEL STEP COUNTERS ',

  • PM DID NOT ACTIVELY OR PASSIVELY CONTRIBUTE TO FLRCS PROBLEM

e WESTINGHOUSE CARD TESTER DOES NOT TEST ALL CIRCUIT DIODES

WHICH COMPLICATED TROUBLESHOOTING

  • PIN CONNECTIONS/CONTACTS PROBLEMS EXISTED AT THREE (3) OTHER

WESTINGHOUSE SITES

e OTHER

- PARTS PROCUREMENT

-

OUTAGE COMPLETION INFLUENCE

-

VENDOR CONTROLS/COMPLIANCE

t':- .. -

83MM3-18

. -

w* *.

J

SALEM UNIT 2

ROD CONTROL SYSTEM

CORRECTIVE ACTIONS

. IMMEDIATE

  • OPERATIONAL

-

DEVELOP AND IMPLEMENT SAFETY

EVALUATION FOR CONTINUED SAFE

OPERATION

COMPLETE

-

STANDING ORDERS IN EFFECT

COMPLETE

-

CURRENT TRACES WILL BE PERFORMED

PRIOR TO EACH STARTUP

COMPLETE

-

FOR UNIT 2 INCREASED SURVEILLANCE

TESTING FOR IRPI VERIFICATION

COMPLETE

-

APPROPRIATE PROCEDURES HAVE BEEN

REVIEWED FOR ADEQUACY TO

IDENTIFY AND ADDRESS ABNORMAL

ROD MOVEMENT

COMPLETE

-

ESTABLISH IMPROVED PRACTICE(S)

  • BEFORE S/2 CARP

FOR CARD REMOVAL/INSTALLATION

REPLACEMENT

NMMl-27

..

..

SALEM UNIT 2

ROD CONTROL SYSTEM

CORRECTIVE ACTIONS

IMMEDIATE

e OPERATIONAL (CONTINUED)

-.OPERATORS TRAINED AT SIMULATOR

FOR UNEXPECTED ROD MOTION

-CONTINUE NOTIFICATION TO THE

INDUSTRY OF THE SALEM INCIDENT

  • MODIFICATIONS

-

INSTALLATION OF SUPRESSION DIODES

FOR BOTH UNITS

-

REPLACE ROD CONTROL LOGIC

CARDS - UNIT 2

-

IMPLEMENT STATIC CHARGE CARD

HANDLING GUIDANCE

PMM3-2t

COMPLETE

ONGOING

IN PROGRESS

BEFORE STARTUP

COMPLETE

,; .....

  • *
  • -

SALEM UNIT 2

ROD CONTROL SYSTEM

CORRECTIVE ACTIONS

LONG TERM

e MANAGEMENT ISSUES

- COMPLETE SERT EVALUATION AND IMPLEMENT

APPROVED RECOMMENDATIONS

- PROVIDE IMPROVED GUIDANCE FOR THE CONDUCT AND

CONTROL OF MAINTENANCE TROUBLESHOOTING

ACTIVITIES

- PARTICIPATE WITH WOG FOR RESOLUTION OF GENERIC

ISSUES

- ESTABLISH A "LESSONS LEARNED" TEAM BETWEEN

WESTINGHOUSE AND PSE&G FOR CONTRACTOR

SERVICES

- PROVIDE PROCEDURAL GUIDANCE FOR ROOT CAUSE

ADEQUACY

e MODIFICATIONS

- CHANGE MECHANICAL STEP COUNTERS TO DIGITAL

STEP COUNTERS

~

~-

SALEM UNIT 2

ROD CONTROL SYSTEM

SUMMARY CONCLUSIONS

e SIGNIFICANCE OF SINGLE ROD WITHDRAWAL AS A FUNCTION

OF A SINGLE FAILURE NOT IDENTIFIED SOON ENOUGH

RESULTING IN INAPPROPRIATE DECISION TO RESTART

e SUBSEQUENT TO RECOGNITION OF SIGNIFICANCE,

COMPREHENSIVE TROUBLE SHOOTING, REPAIR, ROOT CAUSE

EVALUATION

e CONSERVATIVE ACTION TO SHUTDOWN UNIT 2 AND MAINTAIN

UNIT 1 SHUTDOWN FOLLOWING TRIP

e COMPREHENSIVE SAFETY ASSESSMENT PERFORMED

e COMPENSATORY ACTIONS IN PLACE TO PROVIDE ADDmONAL

ASSURANCE

e THOROUGH CORRECTIVE ACTIONS TAKEN/UNDERWAY

e CONTINUING DETAILED SELF*ASSESSMENT BY SERT

e MODIFICATIONS TO ROD CONTROL SYSTEMS IN PROCESS

e MANAGEMENT ISSUES IDENTIFIED AND BEING ADDRESSED

e PSE&G ACTIVELY SUPPORTING LONG TERM RESOLUTION WITH

w.o.G.

SAFE, CONSERVATIVE APPROACH TO REACTOR SAFETY LEAD

TO DETAILED SAFETY ANALYSIS TO ADDRESS GENERIC ISSUE

NMM3*36

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