ML20086A275

Part 21 Rept Re Several Incidents of Instrument Drift in Excess of Specified Limits for Rosemount Pressure Transmitter Model 1154SH9.Other Licensees Advised to Be Alert to Differences in Pressure Indication

ML20086A275
Person / Time
Site:	Surry
Issue date:	06/27/1995
From:	Saunders R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-95 95-318, NUDOCS 9507030139
Download: ML20086A275 (4)

Text

W g ?e VIRGINIA ELECTHIC AND POWER COMPANY i s' Rici Mono, VIRGINIA 202 61 June 27,1995 U. S. Nuclear Regulatory Commission Serial No.95-318 Attention: Document Control Desk NL&P/DAS Washington, D.C. 20555 Docket Nos. '50-280 50-281 License Nos. DPR-32 ,

DPR-37 Gentlemen:

VIRGINlA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 NOTIFICATION OF DEFECT IN ACCORDANCE WITH 10 CFR 21 ,

. Virginia Electric and Power Company (Virginia Power) has identified several incidents 4 of instrument drift in excess of specified limits for the Rosemount pressure transmitter Model 1154SH9. In accordance with 10 CFR 21.21, the following information is provided as written notification of an existing defect.

1. Name and address of the individual or individuals informing the Commission.

Mr. R. F. Saunders Vice President - Nuclear Operations Virginia Einctric and Power Company 5000' Dominion Boulevard Glen Allen, Virginia 23060

2. Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect.

Surry Power Station Units 1 and 2 Rosemount Pressure Transmitter Model 1154SH9

3. Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

Rosemount Aerospace Inc.

1256 Trapp Road Eagan, MN 55121 Attn: Mr. K. Ewald Business Unit Manager 300071 9507030139 950627 0 PDR ADDCK 05000280 /

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4. Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.

In February 1995, Virginia Power initiated a root cause evaluation (RCE) to determine me cause of calibration discrepancies identified with the pressurizer pressure protection transmitters. During this evaluation, three spare Model 1154SH9 transmitters were tested in an oven to determine if they were affected by temperature variations. As a result of this testing and readings taken in the process racks, Virginia Power concluded that some Rosemount Model 1154SH9 pressure transmitters were exhibiting instrument drift greater than specification. This drift was due to changes in containment ambient temperature between calibration during shutdown and normal operations.

Affected transmitters exhibited a zero shift in the negative direction of between 6 '

and 15 psig. This shift was greater than the 5.8 psig shift expected for such temperature variation as specified in Rosemount Product Data Sheet PDS 2631/4631 Rev 8/93 and the Part 21 letters from Rosemount to Virginia Power on May 27,1993 and August 31,1993. Although this instrument drift was not safety significant for Surry, it was a causal factor in an incident in which Unit 2 pressurizer pressure channels had been set outside of Technical Specification limits. Accordingly, it was determined that given the variability observed in instrument drift and the multiple examples of occurrence, this condition could have the potential to be safety significant in other similar safety-related applications at other facilities dependent on plant specific setpoint margins.

Specific applicability with respect to safety systems or licensee facilities is not known.

5. The date on which the information of such defect or failure to comply was obtained.

April 26,1995

6. In the case of a basic component which contains a defect or fails to comply, the number and location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulation in this part.

There are twelve Model 1154SH9 pressure transmitters at Surry: three installed in Unit 1 for pressurizer pressure, three installed in Unit 2 for pressurizer pressure, and six spares. Only the three Unit 2 pressurizer pressure transmitters and one spare have exhibited excessive instrument drift and are therefore affected by this notification. There are seven Model 1154SH9 pressure transmitters at North Anna: three installed in Unit 1 for pressurizer pressure, three installed in Unit 2 for pressurizer pressure and one spare.

Excessive instrument drift has not been observed in the transmitters presently installed. (One previous Unit 2 transmitter, which had exhibited excessive shift, was replaced earlier with a spare.)

7. The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.

o As stated above, Virginia Power performed an RCE which resulted in the identification of the excessive instrument drift concern, the variability of the degree of drift between individual transmitters, and the individual transmitter applicability (i.e. not all Model 1154SH9 transmitters exhibit excessive drift).

Individual instrument channels-identified as subject to the excessive drift phenomena were evaluated to ensure continued operability by establishing that the individual transmitter drift was within overall channel setpoint margins.

The NRC was advised of our preliminary findings in a meeting with Region ll on April 24,1995. Copies of our RCE were provided to the resident inspectors.

The industry was notified of our RCE findings in an INPO Network entry made oriJune 15,1995, which addressed various calibration enors identified with the pressurizer pressure protection transmitters.

We will continue to work with the manufacturer and intend to ship one of the transmitters exhibiting excessive drift for future investigations of the condition we have observed.

8. Any advice related to the defect or failure to comply about the facility, activity or basic component that has been, is being or will be given to purchasers or licensees.

Virginia Power advises other licensees to be alert to differences in pressure indication between individual Model 1154SH9 transmitters as well as between functional groupings of Model 1154SH9 transmitters and other related but non-Model 1154SH9 pressure indications. Either circumstance might indicate the presence of excessive shift. Furthermore for temperature sensitive applications, consideration should be given in the interim to temperature testing Model 1154SH9 transmitters prior to use to determine actual temperature related shifts.

Should you have any questions or require additional information, please contact Mr. M. L. Bowling, Manager Nuclear Licensing and Programs, at (804) 273-2699.

Very truly yours, R. F. Saunders Vice President - Nuclear Operations 1

I

.d' i cd: U. S. Nuclear Regulatory Commission.

Region 11 ,

'101 Marietta Street, N. W.

Suite 2900  :

Atlanta, Georgia 30323 -

Mr. M. W. Branch +

NRC Senior Resident inspector Suny Power Station

' Mr. R. D. McWhorter NRC Senior Resident Inspector  ;

North Anna Power Station -

Mr. K. Ewald - '

Business Unit Manager Rosemount Aerospace Inc.

1256 Trapp Road ~

Eagan, Minnesota 55121 i

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