ML17212A628
| ML17212A628 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Monticello, Peach Bottom, Nine Mile Point, Grand Gulf, Pilgrim, Duane Arnold, Crane  |
| Issue date: | 07/24/2017 |
| From: | David Brown Lake Engineering Company |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML17212A628 (2) | |
Text
U S Nuclear Regulatory Commission Attn: Document Control Room Washington, DC 20555-0001 LAKE ENGINEERING CO.
P.O. Box296 1.0 Austin Avenue Greenville, RI 02828 Tel: 401-949-4733 Fax: 401-949-0220 July 24, 2017
Subject:
Potentially Degraded Snubber SF1154 Hydraulic Fluid Second Interim Notification per 10 CFR Part 21 This letter is a follow up to our initial notification letter dated May 1, 2017 pertaining to the above subject.
Fluid Evaluation by Lake Engineering Company (LEC)
In our previous evaluations, evidence of white semisolid material was identified only in containers of fluid that had not been filtered by LEC prior to shipment. At that time it was postulated that our filtration process may have eliminated any existing semisolid material and precluded the existence of such material thereafter. Subsequent to our initial report dated May 1, 2017, evidence of the white semisolid material was identified in samples of fluid that had, in fact, been filtered prior to shipment. It was therefore concluded that, although filtration will remove preexisting semisolid material it will not preclude its generation thereafter.
Evaluation by Momentive Performance Materials The white semisolid material observed in Batch 14ELVS145 has been identified as a phenyl cyclic precipitate. Phenyl cyclic is a typical byproduct that normally exists in solution in all dimethyl diphenyl polysiloxane. The propensity for precipitation may be associated with the overall level of cyclics in the fluid. Efforts are ongoing to finalize a purification process that will significantly reduce the level of phenyl cyclics in future batches.
US Nuclear Plants to Which Fluid from Batch 14ELVS145 Was Shipped by LEC The following table reflects the status of US plants to which SF1154 fluid from Batch 14ELVS145 was shipped by Lake Engineering Company (LEC):
U S Nuclear Regulatory Commission July 24, 2017 Page2 Potentially Degraded Snubber SF1154 Hydraulic Fluid Millstone Installed snubbers with Batch 14ELVS145 Evaluation ongoing Nine Mile Point Fluid not used No substantial safety hazards Duane Arnold Fluid not used No substantial safety hazards Monticello Fluid not used No substantial safety hazards Pilgrim Fluid not used No substantial safety hazards Three Mile Island Installed snubbers with Batch 14ELVS145 Evaluation ongoing Grand Gulf Installed snubbers with Batch 14ELVS145 Evaluation ongoing Peach Bottom Installed snubbers with Batch 14ELVS145 Evaluation ongoing Further Action by Lake Engineering Company Lake Engineering Company shall continue in its evaluation to determine whether the subject anomalies represent defects which could create a substantial safety hazard. Determination in this regard shall continue to involve interaction between Lake Engineering Company and plants listed above that have installed snubbers with Batch 14ELVS145 fluid.
Our goal is to complete the evaluation by October 31, 2017 at which time a final determination will have been made as to whether a substantial safety hazard exists. If additional time is required for the above determination, an interim report shall be submitted that shall include an updated completion date.
If there are any questions or if additional information is required, please contact the writer by mail or by phone using the contact information provided above or by email at dbrown@lakeengineeringri.com.
DPB/d/let072417.nrc cc: P. Guay - QA Mgr.
Very truly yours, LAKE ENGINEERING COMPANY
- 0. P. Brown, P.E.
President