Part 21 Report - 2001-010

 

 

Rosemount Nuclear Instruments	Rosemount Nuclear Instruments, Inc.
	12001 Technology Drive
	Eden Prairie, MN 65344 USA
	Tel: (952)628-6252
	Fax: (952)628-8260

12 December 2000

Re: Notification under 10 CFR Part 21 for Rosemount Model 710 Trip Unit

Pursuant to 10 CFR Part 21 Paragraph 21.21(b), Rosemount Nuclear lnstruments, Inc. (RNII) is writing to inform you of a deviation related to a single model 7I0DU0CL calibration unit with serial number 0515346. As a result of an isolated human error, this single calibration unit was originally shipped in Ju1y 1998 with the stable calibration current ramp rate out of specification. This deviation was identified when the calibration unit was returned to Rosemount Nuclear lnstruments, Inc for an unrelated issue. The calibration unit has been reworked and now performs within specification.

References (attached):	(1) Rosezno~nt Specification Drawing for Nuclear Qualified 710DU Trip/Calibration System 00710-0109 section 5.3.2
	(2) Acceptance Test Specification for Nuclear Qualified 710DU Trip/Calibration System 00710-3322 section 4.71 (3) Model 710DU Trip/Calibration System Operations Manual MAN 4471-1, April 1983 p.11 Stable Current Calibration

1.0 Name and address of the individual providing the information:

Mr. Jeffrey W. Schmitt
Vice President & General Manager
Rosemount Nuclear Instruments, Inc.
12001 Technology Drive
Eden Prairie, MN 55344

2.0 Identification of items supplied:

710DU0CL, Serial number 0515346

FlSHER-ROSEMOUNT

10CFR21 notification

12 December 2000

Page 2 of 3

3.0 Identification of firm supplying the item:

Rosemount Nuclear Instruments, Inc.
12001 Technology Drive
Eden Prairie, MN 55344

4.0 Nature of the failure and potential safety hazard:

The decreasing current ramp rate on model 710DU0CL calibration unit, serial number 0515346, was slow out of specification. Thc specified rate is 1.0 + 0.1 mA per second and the rate for this unit was 0.7 mA per second.

Slow ramp rate means that calibration current used to calibrate Master or Slave Trip Unit trip points would take more time than specified to rarnp from one current value to another. During calibratiori operations, this calibration current is displayed on the readout assembly.

RNII does not have sufficient information to determine what the safery impact would have been as it related to the Licensee's plant operations. The customer for this unit has been advised.

5.0 The corrective action which is taken, the name of the individual or organization responsible tor that action, and the length of time takeri to complete that action:

The model 710DU0CL calibration unit serial number 0515346 has been reworked by replacing resistor R42 so that the decreasing stable calibration current ramp rate is within specification.

As a precautionary measure, we reviewed travel cards which document acceptance test procedure (ATP) results during manufacturing for all model 710DU0CL calibration units manufactured over the past four years to ensure that there were no other deviations of this type.

Additionally, the model 710DU0CL travel card was proactively revised in June 1999 to more clearly state the specification limits for this portion of the acceptance test procedure (ATP). An independent inspection is performed to verify that the value for the decreasing stable calibration current ramp rate recorded on every travel card is within specification.

FISHER-ROSEMOUNT

10CFR2I Notification

12 December 2000

Page 3 of 3

6.0 Any advice related to the potential failure of the item:

The end user must determine the full scope of this deviation as it relates to plant operations and plant safety and take action as deemed necessary.

Rosemount Nuclear Instruments. Inc. has a strong commitment to the nuclear industry and assures you that we are dedicated to the supply of high quality products and services to our custorners. We are sorry for any inconvenience. If there are any questions, or you require additional information related to this issue, please contact Jerry Edwards (952) 828-3951, Mike Dougherty at (952) 828-5626 or Bob Cleveland at (952) 828-8255.

Sincerely,

ROSEMOUNT NUCLEAR INSTRUMENTS, INC.

Jeffrey W. Schmitt
Vice President & General Manager

Attachrnents (see image file for this Part 21 report-3 pages):

(1) Rosemount Specification Drawing fbr Nuclear Qualified 7l0DU Trip/Calibration System 00710-0109 section 5.3.2

(2) Acceptance Test Specification for Nuclear Qualified 710DU Tnp/Calibration System 00710-3322 section 4.71

(3) Model 710DU Trip/Calibration System Operations Manual MAN 4471-I, April 1983 p.11 Stable Current Calibration

FISHER-ROSEMOUNT