United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9604230034


AMETEK/DIXSON

287 27 Road
Grand Junction, CO 81503
(970) 242-8863 FAX (970) 245-6267

April 18, 1996

To: Whom it may concern
Nuclear Regulatory Commission

The following will serve as official notification of an apparent anomaly that has been identified in the AMETEK/Dixson ProSeries Bargraph models SA101P, SA202P, SN101P, and SNT202P.

The indication caused by the anomaly is as follows:

Depending on the configuration of the specific bargraph, i.e. current or voltage, the unit can potentially, indicate an erroneous under range condition at a very specific input point. Example, if the unit is configured for 4/20mA range, the anomaly can occur at approximately 91% of span.

When the condition occurs the bargraph will indicate a zero reading, on the bargraph portion, indicate dashes on the digital display portion, and the relays (if used) will track this indication. This is typically a momentary condition and the unit immediately returns to normal operation after the anomalous condition stops.

This is a very uncommon condition, and if the condition occurs, the response by the operator is unknown to AMETEK/Dixson since the bargraphs are used in varying applications. It is believed that an incorrect response would be the worst case condition, however it's low probability of occurrence and very short term duration would tend to limit this likelihood.

The probability of this under range condition occurring is perceived to be minimal, due to the very specific and unusual conditions that must be present for it to appear. This condition only has the potential at this specific input point, and even then seldom occurs, i.e. just because it reaches this point doesn't necessarily mean the anomaly will occur. This is supported by the fact that the units in the field represent over 200 million hours of combined successful operation (assuming 24 hour/day usage). We have received only 2 indications (representing 2 bargraphs) from customers referencing this anomaly, and these were both on COMMERCIAL GRADE programmable bargraphs only. THERE HAVE BEEN NO REPORTED INCIDENCES OF THIS ANOMALY ON 1E BARGRAPHS.

During the initial troubleshooting of the anomaly indicated on the commercial product, it was discovered that the same condition existed in the 1E programmable bargraph software on April 16, 1996 at 1730, and thus the generation of this notification.

AMETEK/Dixson Engineering has isolated the condition, determined that it is a software function. This software was designed and supplied by AMETEK/Dixson. A change has been identified, and a new version is currently being generated by AMETEK-/Dixson to resolve the issue.

AMETEK/Dixson Sales Department has identified all affected units, and is currently in the process of notifying affected customers, with specifics a function of their application.

AMETEK/Dixson does not believe this represents a significant risk to normal operation but, has taken the appropriate actions to ensure the integrity of operation of all affected organizations. These actions are as follows:

1) Notified the NPC, per 10CFR50 part 21 on 4-18-96.
2) Currently notifying the affected users. Expected completion date is 4-22-96.
3) Identified the nature of the anomaly on 4-16-96.
4) Identified the changes required to resolve the anomaly on 4-17-96.
5) Currently in the process of incorporating the identified changes. The completion date depends on the specific customer response to this notification.

Reference the attached list, that represents the affected users, and potentially affected quantities involved.

Sincerely,

Clyde Huber
Quality assurance Engineer


April 18, 1996

The Following is a list of all AMETEK/Dixson customers that have received Class 1E "Pro" series indicators. It includes the address of the plant location and the number of indicators purchased.

Cegelec Automation L G Industrial Systems Co. Ltd.
2806 Metropolitan Place 20 Yoido-Dong, Youngdungpo-Gu
Pamona, Ca. 91767 Seoul, Korea
Qty: 267 Qty: 13
 
Entergy Operations Northeast Nuclear
Arkansas Nuclear One Milestone Site
South of Jet Hwy. 64W and 333 S Rt. 156 Rope Ferry Rd.
Russellville, Ar. 72801 Waterford, Ct. 06386
Qty: 53 Qty: 2
 
Florida Power and Light Omaha Public Power District
St. Lucie NPP Fort Calhoun Station
6501 South A1A Gate E Fort Calhoun, Ne. 68023
Jensen Beach, Fl. 34957 Qty: 6
Qty: 2
 
Florida Power Corp. Georgia Power Co.
Crystal River Unit 3 Plant E.I. Hatch
15760 Powerline St. Baxley, Ga. 31513
Crystal River, Fl. 34428 Qty: 2
Qty: 18


GENERAL INFORMATION or OTHER EVENT NUMBER: 30312
LICENSEE: AMETEK/DIXSON NOTIFICATION DATE: 04/18/96
CITY: GRAND JUNCTION REGION: 4 NOTIFICATION TIME: 18:28 [ET]
COUNTY: MESA STATE: CO EVENT DATE: 04/16/96
LICENSE#: AGREEMENT: Y EVENT TIME: 17:30[MDT]
DOCKET: LAST UPDATE DATE: 04/18/96
NRC NOTIFIED BY: CLYDE HUBER NOTIFICATIONS
HQ OPS OFFICER: JOHN MacKINNON VERN HODGE (NRR) PECD
EMERGENCY CLASS: NOT APPLICABLE
10 CFR SECTION: CDEG 21.21(c)(3)(i) DEFECTS/NONCOMPLIANCE

EVENT TEXT

AMETEK/DIXSON PROSERIES BARGRAPH MODELS SA101A, SA202P, SN101P, AND SN202P UNITS CAN POTENTIALLY INDICATE AN ERRONEOUS UNDER RANGE CONDITION AT A VERY SPECIFIC INPUT POINT.

THE FOLLOWING PORTION OF THIS TEXT IS TAKEN FROM A FACSIMILE RECEIVED FROM AMETEK/DIXSON, LOCATED IN GRAND JUNCTION, CO.

" ... AN APPARENT ANOMALY HAS BEEN IDENTIFIED IN THE AMETEK/DIXSON PROSERIES BARGRAPH MODELS SA101P, SA202P, SN101P, AND SN202P.

"THE INDICATION CAUSED BY THE ANOMALY IS AS FOLLOWS:

"DEPENDING ON THE CONFIGURATION OF THE SPECIFIC BARGRAPH, i.e. CURRENT OR VOLTAGE, THE UNIT CAN POTENTIALLY INDICATE AN ERRONEOUS UNDER RANGE CONDITION AT A VERY SPECIFIC INPUT POINT. EXAMPLE, IF THE UNIT IS CONFIGURED FOR 4/20mA RANGE, THE ANOMALY CAN OCCUR AT APPROXIMATELY 91% OF SPAN.

"WHEN THE CONDITION OCCURS, THE BARGRAPH WILL INDICATE A ZERO READING ON THE BARGRAPH PORTION, INDICATE DASHES ON THE DIGITAL DISPLAY PORTION, AND THE RELAYS (IF USED) WILL TRACK THIS INDICATION. THIS IS TYPICALLY A MOMENTARY CONDITION, AND THE UNIT IMMEDIATELY RETURNS TO NORMAL OPERATION AFTER THE ANOMALOUS CONDITION STOPS.

THIS IS A VERY UNCOMMON CONDITION, AND IF THE CONDITION OCCURS, THE RESPONSE BY THE OPERATOR IS UNKNOWN TO AMETEK/DIXSON SINCE THE BARGRAPHS ARE USED IN VARYING APPLICATIONS. IT IS BELIEVED THAT AN INCORRECT RESPONSE WOULD BE THE WORST CASE CONDITION, HOWEVER, IT'S LOW PROBABILITY OF OCCURRENCE AND VERY SHORT TERM DURATION WOULD TEND TO LIMIT THIS LIKELIHOOD."

AMETEK/DIXSON IS CURRENTLY NOTIFYING THE AFFECTED USERS (EXPECTED COMPLETION DATE IS 4/22/96). THE FOLLOWING IS A LIST OF POWER PLANTS THAT HAVE RECEIVED THE CLASS 1E "PRO" SERIES INDICATORS: ENTERGY OPERATIONS: ARKANSAS NUCLEAR ONE FLORIDA POWER AND LIGHT: ST. LUCIE NPP

FLORIDA POWER AND LIGHT: CRYSTAL RIVER UNIT 3

NORTHEAST UTILITY: MILESTONE SITE

OMAHA PUBLIC POWER DISTRICT: FORT CALHOUN STATION

GEORGIA POWER CO.: PLANT HATCH

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