ML18179A163

Retraction of Licensee Event Report 2018-002-00, Diesel Generator a Inoperability, a Condition Prohibited by the Plant Technical Specifications

ML18179A163
Person / Time
Site:	Pilgrim
Issue date:	06/21/2018
From:	Miner P Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 2018-002-00
Download: ML18179A163 (2)

Text

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Entergy Nuclear Operations, Inc.

Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 June 21, 2018 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Retraction of Licensee Event Report 2018-002-00, Diesel Generator A lnoperability, a Condition Prohibited by the Plant Technical Specifications Pilgrim Nuclear Power Station Docket No. 50-293 Renewed License No. DPR-35

REFERENCES:

1. Letter from P. J. Miner (Entergy) to U.S. Nuclear Regulatory Commission, Licensee Event Report 2018-002-00: Diesel Generator A lnoperability, a Condition Prohibited by the Plant Technical Specifications, dated March 6, 2018 (ADAMS Accession No. ML18079A104, Pilgrim Letter 2.18.013)

LETTER NUMBER: 2.18.041

Dear Sir or Madam:

In accordance with NUREG-1022, Revision 3, Section 5.1.2, Pilgrim Nuclear Power Station (PNPS) is cancelling (formally withdrawing) Licensee Event Report (LER) 2018-002-00, submitted to the U.S. Nuclear Regulatory Commission on March 6, 2018 (Reference1). The LER reported, pursuant to Title 1O Code of Federal Regulations (CFR) 50.73(a)(2)(i)(B), any operation or condition which was prohibited by the plant's Technical Specifications. Subsequent to submittal of LER 2018-002-00,- Entergy completed its reevaluation of the condition and determined that it no longer constitutes a reportable condition pursuant to 10 CFR 50.73 and NUREG-1022 guidance.

Based on an Engineering evaluation, supported by additional information provided by offsite vendors, Entergy has concluded that the conditions discussed in the LER would quickly be resolved if additional load was added due to accident conditions. The brush chatter would be expected to subside and visual indications return to the level that had been observed during the previous surveillance operation on December 29, 2017, with no additional wear than that which the other brushes had demonstrated.

Additional information evaluated includes a section of the U.S. Navy Technical Manual for Commutator/Slip Ring Maintenance Handbook which discusses direct current (DC) brush chatter. As brushes ride on a rotating collector surface there is a tendency for the friction of the rotating surface to cause a vibration in the brush. The brush holders and springs have the primary role of dampening out these vibrations. When the amplitudes of these brush

Entergy Nuclear Operations, Inc. Letter No. 2.18.041 Pilgrim Nuclear Power Station Page 2 of 2 vibration frequencies are audible, chatter is present. Chatter often occurs when lightly loaded brushes ride on commutator surfaces. This chatter quickly disappears once sufficient load is applied. The "A" Emergency Diesel Generator (EOG-A) was in low loading operation at the time of discovery which explains why this condition was not seen during the most recent past surveillance test, where EOG-A was operated at full load.

Based on the Engineering evaluation, it is reasonable to conclude that EOG-A, was operable at the time of discovery. Moreover, if called upon to do so, EOG-A would have performed its specified safety function for the 30-day mission time.

Therefore, based upon this conclusion, PNPS is cancelling (formally withdrawing)

LER 2018-002-00.

Should you have any questions or require additional information, contact me at (508) 830-7127.

There are no new regulatory commitments contained in this letter.

Sincerely,

1Ji~

PeterJ.

• er Manage , Regulatory Assurance PJM/sc cc: Mr. David C. Lew Acting Regional Administrator, Region I U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd., Suite 100 King of Prussia, PA 19406-2713 Mr. John Lamb, Senior Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8C2A Washington, DC 20555 NRG Senior Resident Inspector Pilgrim Nuclear Power Station