Part 21 Report - 1997-511
ACCESSION #: 9708080191
15000 Highlands Parkway
Smyrna, GA 30082
Tel: (770) 432-2744
Fax: (770) 432-9179
Via: Fax and Courier
5 August 1997
US NRC Headquarters Operations Center
Document Control Desk
Nuclear Regulatory Commission
Washington DC 20555
Subject: 10 CFR 21.21 Notification. MGP Instruments Inc.
Radiation Monitoring System, power supply circuit board is
subject to premature electronic component failure
Dear Madam or Sir,
On 12 June 1997 MGP Instruments Inc. (MGPI Inc.) became aware of a
potential safety related defect involving a power supply board installed
in a family of local processing units (LPU). These LPUs were delivered
for use in a safety related application as part of a radiation monitoring
system. Although it has been confirmed that the equipment is not in
active service, MGPI wishes to formally notify the commission, and the
affected utility, in accordance with the requirements of 10 CFR Part 21.
During field maintenance of local processing units (used in a European
non-safety related application), MGP Instruments Inc's sister
organization (MGPI SA) advised that some of the power supply boards were
found to have an electronic component failure. No such failure had been
observed by MGP Instruments Inc. applications, within the US, prior to
the information received.
28 LPUs of a similar design, which contain the power supply circuit
board, with the suspect component, were qualified for use in a safety
related application and delivered to Southern California Edison for use
at their San Onofre Nuclear Generation Station.
MGP Instruments Inc. has completed a technical review and concluded that
the diode VD-9 (model 1N4148), installed on the MGPI proprietary power
supply boards (part nos. RMS-9077-SR and RMS-9068-SR), is susceptible to
failure during equipment start-up. This failure is due to the
insufficient rating of the diode under transient conditions (non-
repetitive peak forward current).
Failure of diode VD-9 will result in a loss current passing through the
coil of electronic relay K1. Following diode failure, the relay will not
be energized, and the battery required for the processor's,
memory back up will not be charged. Accordingly, following eventual
battery discharge, the LPU may be unable to re-start with correct
The safety related application of this device is limited to its
installation in the 28 units at Southern California Edison's San Onofre
Nuclear Generating Station (serial number listing indicated in attachment
A). A recent inquiry to the utility indicated that the affected equipment
has not been commissioned and is not yet in service, (see attachment B).
The diode will be replaced with an appropriate component, by MGPI's
qualified technicians, in accordance with documented procedures, prior to
the commissioning of the equipment.
Nuclear Regulatory Commission Page: 2
MGP Instruments Inc. is providing the following in accordance with 10
CFR 21.21 (c) (4). Initial notification of this matter will be provided
by facsimile of this letter to the NRC Operations Center in accordance
with 10 CFR 21.21 (c) (3) within two (2) days of the date the responsible
officer signs this letter.
I. Kenneth F. Rosanski, Senior Vice President MGP Instruments
Inc., 5000 Highlands Parkway, Suite 150 Smyrna Georgia, 30082
is the responsible officer notifying the Nuclear Regulatory
Commission under the provision of 10 CFR Part 21.
II. The basic component involved in this condition are the Local
Processing Units (LPUs) bearing the MGP Instruments Inc. part
numbers RMS-9040-SR, RMS-9041-SR, RMS-9042-SR and RMS-9086-SR.
III. The local Processing Units indicated in (II) above have been
manufactured by MGP Instruments Inc., Smyrna Georgia. The
units were qualified for safety related applications.
IV. The Southern California Edison Procurement Specification SO123-
060-12 (rev. 2 January 16 1995) requires that the processors
"Sense the loss of power and conduct an orderly shutdown..."
and "Upon restoration of power, restart immediately and
automatically and function in accordance with the requirements
of [the specification]." Specification references 220.127.116.11.3.1
&2 Page A-56). Failure of the diode VD-9, located on the local
processing units power supply board, will result in the
processor's battery back-up battery not being charged,
preventing orderly processor shutdown and re-start with correct
V. The possibility of the diode failure was identified as
potentially reportable under the provisions of 10 CFR 21 on 12
June 1997. A technical review, completed on 5 August 1997 and
confirmed that there was a potential for safety impact.
VI. Southern California Edison, San Onofre Nuclear Generation
Station has 28 safety related local processing units. At this
time none of the units have been found to have the failure mode
described in (IV) above. Additionally, MGP instruments Inc.
has been advised that the safety related processors are not
presently in service. Safety related processing units affected
include those listed in attachment A of this notification.
VII. MGP Instruments Inc. will take the following corrective
action: The diode VD-9 on LPU power supply boards (part numbers
RMS-9077-SR and RMS-9068-SR) will be replaced with a diode
(model 1N4004) which will withstand the non-repetitive peak
forward current which could occur during startup.
VIII. MGP Instruments Inc. recommends that Southern California
Edison not put the affected units in service until the power
supply boards are reworked, by MGP Instruments.
Nuclear Regulatory Commission Page: 3
Additional information about this issue may be obtained by contacting the
undersigned or Mr. David Jarrow MGP Instruments Inc. Quality Assurance
Manager at (770) 432-2744, extension 119.
Kenneth F. Rosanski
Senior Vice President
Attachment A: Equipment Serial Number and Location Listing
Attachment B: e-mail from Southern California Edison Dated 4 August 1997
cc: Southern California Edison - Mr. Ken Slagle, Manager Nuclear
Southern California Edison - Mr. Ray Baker, Project Manager, RMS
MGP Instruments SA, Lamanon France: X. Duquesne, F. Chlosta, B.
A. Pommier, P. Stolpe
MGP Instruments Inc. Atlanta: Mr. David Jarrow, Mr. Mike Edelmen,
Mr. Sergio Lopez
Nuclear Regulatory Commission Page:4
SCE San Onofre Safety Related LPU Serial Number Listing
P.O. Unit Type P/N Quan. S/N SCE Location
6V2D3002 LPU/PIPS/NG RMS-9040-SR 4 960203 3re7822
LPU/PIPS/P RMS-9041-SR 4 960203 3re7804
LPU/SAS RMS-9042-SR 6 960102 3re7808
LPU/IO RMS-9086-SR 8 960101 2ryj7865
6E256015 LPU/PIPS/NG RMS-9040-SR 2 960202 SCE Warehouse
(Spares) 960204 SCE Warehouse
LPU/PIPS/P RMS-9041-SR 2 960202 SCE Warehouse
960206 SCE Warehouse
LPU/SAS RMS-9042-SR 2 960205 SCE Warehouse
960210 SCE Warehouse
From: RAY BAKER
To: NUC.CURRANJM at WEST7 @ccgateout.songs.sce.com:
NUC.PHILLICA at WEST7 @ccegateout.songs.sce.com
Cc: medelman @mgpi.com
Subject LETTER TO MGPI ON RMS EQUIPMENT STATUS
Date: Monday, August 04, 1997 12:44 PM
Carolyn==Please type this letter on Edison International
letter head. You also need to finish the salutation stuff by adding
Jariath's name, return address etc.
ray b. 8/4
August 4, 1997
Dr. Mike Edelman
5000 Highlands Parkway
Smyrna, GA 30082
Subject: Status of RMS Equipment
Dear Mike Edelman,
This letter confirms a telephone conversation you had recently with Ray
Baker, RMS Project Coordinator regarding the status of the RMS Equipment.
None of this equipment has been made operational as of this date.
J. M. CURRAN
RMS Project Manager
GENERAL INFORMATION or OTHER EVENT NUMBER: 32725
LICENSEE: MGP INSTRUMENTS, INC. NOTIFICATION DATE: 08/05/97
CITY: SMYRNA REGION: 2 NOTIFICATION TIME: 14:57
COUNTY: FULTON STATE: GA EVENT DATE: 06/12/97
LICENSE#: AGREEMENT: Y EVENT TIME: 00:00 [EDT]
DOCKET: LAST UPDATE DATE: 08/05/97
PHIL HARRELL, REG 4 RDO
JOHN GREEVES, NMSS EO
NRC NOTIFIED BY: KENNETH ROSANSKI KEVIN RAMSEY, NMSS IMOB
HQ QPS OFFICER: LEIGH TROCINE VERN HODGE, NRR RVIB
CHRIS CHRISTENSEN R2DO
EMERGENCY CLASS: NOT APPLICABLE AL CHAFFEE, NRR EO
10 CFR SECTION:
CDEG 21.21(c)(3)(i) DEFECTS/NONCOMPLIANCE
10 CFR PART 21 NOTIFICATION REGARDING THE DISCOVERY THAT A RADIATION
MONITORING SYSTEM POWER SUPPLY CIRCUIT BOARD IS SUBJECT TO
ELECTRONIC COMPONENT FAILURE
MGP INSTRUMENTS, INC., LOCATED IN SMYRNA, GEORGIA, REPORTED A
SAFETY-RELATED DEFECT INVOLVING DIODES IN RADIATION DETECTION
EQUIPMENT WHICH WAS SUPPLIED TO SOUTHERN CALIFORNIA EDISON FOR USE
ONOFRE. DIODE VD-9 (MODEL #1N4148) WAS INSTALLED ON PROPRIETARY
SUPPLY BOARDS, AND THIS DIODE IS SUSCEPTIBLE TO FAILURE DURING
START-UP. THE FAILURE IS DUE TO THE INSUFFICIENT RATING OF THE DIODE
UNDER TRANSIENT CONDITIONS (NON-REPETITIVE PEAK FORWARD CURRENT).
FAILURE OF THIS DIODE COULD ULTIMATELY RESULT IN THE INABILITY OF THE
LOCAL PROCESSING UNIT TO RESTART WITH CORRECT OPERATING
THE SAFETY-RELATED APPLICATION OF THIS DEVICE IS LIMITED TO ITS
INSTALLATION IN 28 LOCAL PROCESSING UNITS AT SAN ONOFRE. MGP
INSTRUMENTS, INC., STATED THAT A RECENT INQUIRY OF THE UTILITY
THAT THE AFFECTED EQUIPMENT HAD NOT BEEN COMMISSIONED AND IS NOT
SERVICE. PLANS ARE BEING MADE TO REPLACE THE DIODES WITH
COMPONENTS PRIOR TO THE COMMISSIONING OF THE EQUIPMENT.
(REFER TO THE HOO LOG FOR CONTACT NAMES AND TELEPHONE NUMBERS.)
5000 Highlands Parkway, Suite 150 Tel: (770) 432-2744
Smyrna, Georgia 30082 USA Fax: (770) 432-3179
Date: 5 August 1997 Pages (including cover): 6
To: Ms. Leigh Trocine -NRC Operations From: David Jarrow MGPI QA
cc: Mr. Ken Rosanski - MGP Instruments Inc.
Subject: 10 CFR 21 Notification, Event 32725 @ 14:57 PM 5 August 1997,
MGP Instruments Inc Radiation Monitoring System, power supply
circuit board is subject to premature electronic component
Further to our earlier telephone notification (this date), attached
please find a copy of our notification letter the original of which is
being sent by courier.
This faxacsimile notification is being provided in accordance with the
requirements of 10 CFR 21.21.
Should you have any questions please do not hesitate to contact me at
770-432-2744 X 119
MGP Instruments Inc.
Quality Assurance Manager
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