United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9802100039



POWER REACTOR                                EVENT NUMBER: 33650



FACILITY: NINE MILE POINT     REGION: 1      NOTIFICATION DATE: 02/04/98

UNIT:     [ ]  [2]  [ ]       STATE: NY      NOTIFICATION TIME: 13:50

                                                                 [ET]

RX TYPE:  [1] GE-2, [2] GE-5                 EVENT DATE:        02/04/98

                                             EVENT TIME:         13:50

                                                                 [EST]

NRC NOTIFIED BY: KENNO LAMPMAN               LAST UPDATE DATE:  02/04/98

HQ OPS OFFICER:  JOHN MacKINNON

                                                  NOTIFICATIONS

EMERGENCY CLASS: NOT APPLICABLE

10 CFR SECTION:                              LAURIE PELUSO       RDO

CCCC 21.21          UNSPECIFIED PARAGRAPH

                                             VERN HODGE (PCEB)   NRR



UNIT  SCRAM CODE  RX CRIT  INIT PWR  INIT RX MODE  CURR PWR  CURR RX

MODE

 2        N         Y         95    POWER OPERATION   95  POWER OPERATION



                               EVENT TEXT



10 CFR PART 21:  LOCKUP OF WESTRONICS RECORDERS DUE TO SERVO

AMPLIFIER

BOARD OVERRANGE FEATURE - THIS PROBLEM WAS CORRECTED IN THE FALL

OF 1997.



DESCRIPTION OF CONDITION:



THE DEVIATION DESCRIBED IN THE REFERENCED DEVIATION EVENT REPORTS

(DER)

AFFECTS THE FIVE SAFETY-RELATED (SR) RECORDERS.  RECORDERS

2ISC*LR1623A/B

AND 2ISC*PR1623A/B WERE SUPPLIED TO GENERAL ELECTRIC (GE) BY

WESTRONICS

AS NON-SAFETY-RELATED INSTRUMENTS (NSR) AND WERE UPGRADED TO SR BY

GE

(PURCHASE ORDER/SPEC. P800A).  FUEL ZONE LEVEL RECORDER 2ISC*LR1615

WAS

SUPPLIED AS SR EQUIPMENT AND IS FED FROM TRANSMITTER 2ISC*LT13B.  THE

WIDE RANGE LEVEL RECORDERS 2ISC*LR1623A/B ARE FED FROM TRANSMITTERS

2ISC*LT9A/B.  THE LATTER RECORDERS EACH ALSO DISPLAY VESSEL PRESSURE

ON A

SECOND CHANNEL AND PEN.  THE PRESSURE CHANNELS 2ISC*PR1623A/B ARE

FED

FROM PRESSURE TRANSMITTERS 2ISC*PT16A/B.  ALL OF THE AFFECTED

RECORDERS

ARE ON MAIN CONTROL ROOM PANEL 2CEC*PNL601.  ALL OF THESE RECORDERS

ARE

SR TECHNICAL SPECIFICATIONS POST-ACCIDENT MONITORING INSTRUMENTS. 

THEY

ARE IDENTIFIED ON THE NMP2 MASTER EQUIPMENT LIST AS REGULATORY

GUIDE 1.97

MONITORING EQUIPMENT.  ALL OF THE ABOVE MENTIONED RECORDERS WERE

INSTALLED WHEN THE PLANT WAS INITIALLY LICENSED.



DERs 2-97-1662 AND 2-97-3030 DESCRIBE FAILURES OF THE AFFECTED VESSEL

PRESSURE AND LEVEL RECORDERS LISTED ABOVE SUCH THAT THE AFFECTED

RECORDER

CHANNEL LOCKS UP TEMPORARILY UNDER CONDITIONS WHERE THEY

EXPERIENCE A

LARGE STEP CHANGE IN THE PROCESS VARIABLE MONITORED OR WHEN THE

RECORDERS

HAVE THE PEN MANUALLY MOVED FROM THE POSITION TO WHICH IT WAS

DRIVEN BY

THE SERVO AMPLIFIER BOARD (WESTRONICS PART NUMBER B100124N04).



                        (Continued on next page)



FACILITY:  NINE MILE POINT                PAGE # 2 OF EVENT NUMBER: 33650



ALL OF THE POTENTIALLY AFFECTED RECORDERS NOW ARE (AS OF THE FALL OF

1997) NOW EQUIPPED WITH THE NEWER SERVO AMPLIFIER BOARDS.  THESE

BOARDS

HAVE AN INHERENT TIME DELAY THAT ALLOWS THE BOARD TO FUNCTION

UNDER

TRANSIENT CONDITIONS WITHOUT LOCKING UP.  THERE HAVE BEEN NO

FURTHER

FAILURES (OF THE TYPE DESCRIBED) EXPERIENCED SINCE THE INSTALLATION

OF

THE NEW BOARDS.  THEREFORE, NO FURTHER MAINTENANCE ACTION IS

REQUIRED

WITH RESPECT TO THESE RECORDERS.



PROCUREMENT PERSONNEL HAVE VERIFIED THAT NONE OF THE OLDER MODEL

BOARDS

ARE BEING UTILIZED AT NINE MILE POINT UNIT 1 OR ARE BEING MAINTAINED AS

SPARES.



                                 NIAGARA

                                 MOHAWK



                     NINE MILE POINT NUCLEAR STATION

                  P.O. BOX 63, LYCOMING, NEW YORK 13093



                            FAX COVER LETTER



                         NINE MILE POINT UNIT 2



FROM:     FAX TELEPHONE NUMBER:    (315) 349-1400



          NAME:



          DEPARTMENT:    LICENSING/ENVIRONMENTAL



          TELEPHONE NUMBER:



                                             FAX #



TO:



TOTAL NUMBER OF PAGES FAXED (INCLUDING COVER LETTER):



DATE:          TIME:



MESSAGE:



                      INITIAL PART 21 NOTIFICATION



PLANT:    Nine Mile Point Unit 2



TITLE:    Lockup of Westronics Recorders due to Servo Amplifier Board

          Overrange Feature



DESCRIPTION OF CONDITION:



The deviation described in the referenced DERs affects the five safety

related (SR) recorders.  Recorders 2ISC*LR1623A/B and 2ISC*PR1623A/B were

supplied to GE by Westronics as non-safety related instruments (NSR), and

were upgraded to SR by GE (Purchase Order/Spec. P800A).  Fuel zone level

recorder 2ISC*LR1615 was supplied as SR equipment and is fed from

transmitter 2ISC*LT13B.  The wide range level recorders 2ISC*LR1623A/B

are fed from transmitters 2ISC*LT9A/B.  The latter recorders each also

display vessel pressure on a second channel and pen.  The pressure

channels 2ISC*PR1623A/B are fed from pressure transmitters 2ISC*PT6A/B.

All the affected recorders are on main control room panel 2CEC*PNL601.

All of these recorders are SR Technical Specifications post-accident

monitoring instruments.  They are identified on the NMP2 master equipment

list as RG 1.97 monitoring equipment.



DERs 2-97-1662 and 2-97-3030 describe failures of the affected vessel

pressure and level recorders listed above such that the affected recorder

channel locks up temporarily under conditions where they experience a

large step change in the process variable monitored, or when the

recorders have the pen manually moved from the position to which it was

driven by the servo amplifier board (Westronics part number CB100124N04).

These failures have been identified several times by I&C,and have been

temporarily resolved by resetting the power to the recorder or

recalibrating the recorder.  A newer revision of the same servo amplifier

board from Westronics, part no. CB100124N04 (symbol # 93-23-345) has

eliminated the problem.  Although the newer boards have the same part

number, they may be recognized by different potentiometer identification

numbers.  NMP2 has now installed the newer boards in the potentially

affected recorders (see table below; AFFECTED EQUIPMENT).  However, with

the older servo amplifier boards, the affected recorders could give

readings that are grossly inaccurate due to the pens locking up.



                        TABLE: AFFECTED EQUIPMENT



2ISC*LR1615    Vessel level, Fuel Zone, -165 to 35 in. (single pen)



2ISC*LR1623A   Vessel level, Wide Range, -5 to 205 in. (pen 1/red)



2ISC*LR1623B   Vessel level, Wide Range, -5 to 205 in. (pen 1/red)



2ISC*PR1623A   Vessel pressure 0-1500 psi. (pen 2/blue)



2ISC*PR1623B   Vessel pressure 0-1500 psi, (pen 2/blue)



Although originally supplied SR with an upgraded servo amplifier board,

recorder 2ISC*LR1615 could have at one time been refitted with the old

servo amplifier board during subsequent maintenance activities.  The

remainder of the subject recorders were originally supplied with the old

model boards already installed.



EVALUATION:



Each recorder has one servo amplifier board per channel.  Any single

servo amplifier board may lock-up the affected channel (pressure or

level) under a large step change condition.  There are no alarms or

interlocks generated by the recorders or the internal auxiliary switches.

2ISC*LR1615 uses no internal adjustable auxiliary switches with

setpoints.  The other recorders listed above have internal switches with

high pressure/low level setpoints, but they are only used to switch the

recorder to high speed during the abnormal condition.  They generate no

interlocks or alarms.



The subject recorders are primary monitoring devices for the operators

for post-accident monitoring of the vessel level and pressure, and the

instruments are used by them in the conduct of EOP actions.  These are SR

QA Cat I instruments.  The fuel zone level loop has an alternate SR

indicator on 2CEC*PNL601, which is 2ISC*LI13A (Div. I).  There is an

analog computer point ISCLA101 covering the same fuel zone vessel water

level which would operate independent of the recorder, but it is NSR.

The subject wide range level loops have no associated analog computer

points.  Alternate wide range level indications fed from the same loops

are available on the trip unit indicators on control room panels

2CEC*PNL629 and 2CEC*PNL6l8.  The trip units are SR, but the indicators

are smaller and the location is less convenient for operator reference.

The subject vessel pressure loops have associated analog computer points

ISCPA100 and ISCPA101 which are independent of the recorder problems, but

they are NSR.  All of the above pressure and level ranges are also

available on the Safety Parameter Display System.



Recorder 2ISC*LR1615 is a RG 1.97 Category 1 Type A instrument.  It is

the only RG 1.97 fuel zone water level instrument on Division II.

Recorders 2ISC*LR1623A (Division 1) and 2ISC*LR1623B (Division II) are

the only RG 1.97 Category 1 Type A & B instruments monitoring wide range

reactor vessel water level.  Recorders 2ISC*PR1623A (Division 1) and

2ISC*PR1623B (Division II) are the only RG 1.97 Category 1 Type A, B, & C

instruments monitoring reactor vessel pressure.



As Technical Specification RG 1.97 (Category 1 Type A) post-accident

monitoring equipment, the affected recorders are extensively relied upon

by operators during an accident condition.  The defect described in DER

2-97-3030 is caused by an internal manufacturer's servo amplifier board

design which may lock up any affected channel (pressure or level) under

conditions involving a large step change.  For this reason, the

possibility of failure of any of these recorders due to lockup of the

indication could present a significant safety hazard as described by

10CFR21.



RECOMMENDED CORRECTIVE ACTION (IF REPORTABLE):



All of the potentially affected recorders now are equipped with the newer

servo amplifier boards.  These boards have an inherent time delay that

allows the board to function under transient conditions without locking

up.  No further failures of the type described have been experienced

since the installation of the new boards.  Therefore, no further

maintenance action is required with respect to these recorders.



Procurement has verified that none of the older model boards are being

utilized at Nine Mile Point Unit 1 or maintained as spares.



Since the older model boards have been replaced, the affected instruments

are operable at this time.  GE Company (Mr. Richard Bodily) has been

informed of NMPC's intent to report this defect under 10CFR21.



*** END OF DOCUMENT ***





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