ML20128M409
| ML20128M409 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/02/1985 |
| From: | Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Murley J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| F0720A, F720A, SD-67, NUDOCS 8505310660 | |
| Download: ML20128M409 (2) | |
Text
. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
W
.a General Offices a Seiden Street Berlin, Connecticut
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May 2,1985 Docket No. 50-423 F0720A Dr. Thomas E. Murley Regional Administrator U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406
References:
(1)
W.
G. Counsil letter to T. E.
Murley, F0658A, dated January 11,1985.
(2)
W.
G. Counsil letter to T. E. Murley, F0713A, dated March 14,1985.
Dear Dr. Murley:
Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Accordance with 10CFR50.55(e):
Improper Installation of Conduit Seal for Rosemount Pressure Transmitters (SD-67)
In a Decen. ber 14,1984 telephone conversation between your Mr. T. Rebelowski and our Mr. R. E. Lefebvre, Northeast Nuclear Energy Company (NNECO) reported a potential significant deficiency in the construction of Millstone Unit No. 3 in accordance with 10CFR50.55(e). The potential significant deficiency involved Rosemount differential pressure transmitters with improper conduit installations.
The Rosemount instruction manual requires a qualified thread sealant be applied where the conduit enters the transmitter. This sealant (in this case, grafoil tape) was not used for these transmitters and is necessary to prevent moisture from accumulating in the terminal side of the transmitter housing during accident conditions. Installation of the transmitters without this sealant could cause the transmitters to fail.
As reported to you in Reference (2), we determined that all Rosemount transmitters utilizing Litton Veam connectors were installed without a conduit thread sealant (grafoil tape). An investigation by our architect-engineer, Stone
& Webster Engineering Corporation, revealed that this can be attributed to the J
long time duration between the installation of the Rosemount transmitters and the procurement of the Litton Veam connectors. At the time the transmitters were installed, the Litton Veam connectors had not been selected as the conduit 8505310660 850502 gDR ADOCK 05000423 PM g
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~ V.. '. entry seal for the transmitters, therefore, the grafoil tape was not applied as required by the Rosemount instruction manual.
When the connectors were procured at a later date, they were installed in accordance with the Litton Veam instruction manual which does not require the use of a conduit thread sealant.
Since the transmitters had been installed at a much earlier date, a re-review of the Rosemount instruction manual was not performed and the instructions for applying the grafoil tape overlooked.. Hence, this represents a significant deficiency in the construction of Millstone Unit No. 3.
All Rosemount transmitters utilizing a Litton Veam connector will be reworked to include the grafoil tape by NNECO on a post-turnover basis. In addition, we are still evaluating all instrumentation installations at Millstone Unit No. 3 utilizing Litton Veam connectors to determine whether or not the grafoil tape thread sealant should be applied.
- We are not able to provide a final report at this time. We will provide an update on this matter by August 7,1985.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY A ECwJL 3.I40pbka v
Senior Vice President
- cc:
Mr. J. M. Taylor, Director Division of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D. C. 20555
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