ML12334A492
| ML12334A492 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 07/18/2005 |
| From: | Bonner J - No Known Affiliation |
| To: | Andreozzi V - No Known Affiliation, Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 21523, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12334A492 (2) | |
Text
United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of:
Entergy Nuclear Operations, Inc.
(Indian Point Nuclear Generating Units 2 and 3)
ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #:
Identified:
Admitted:
Withdrawn:
Rejected:
Stricken:
Other:
NYS000041-00-BD01 10/15/2012 10/15/2012 NYS000041 Submitted: December 12, 2011 u.... ~p..p. REG(J~)-
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Bijoor, Gurunath; McCaffrey, Thomas S.; Andreozzi, Vincent Penny, Robert; Bonner, John; Morris, David
Subject:
IPEC Transformer Review This email provides a brief summary of my evaluation of the TPEC main transformers with respect to other ENN fleet transformers.
The IPEC Unit 2 GE transformers are original units, which were manufactured in 1972.
There are two operating issues, which impact the reliability of the IPEC Unit 2 main transformers.
- 1. The power uprate requires that the transformers operate up to 108.1 % above their 55°C rating during period when high MV Ar output is required. Operating above the 55°C rating and into the 65°C rating result in accelerated thermal aging of the transformer insulation.
- 2. The main generator terminal voltage of both IPEC units 2 and 3 are 22kV. IPEC Unit 2 maintains the generator terminal voltage between 20.8kV and 22.6kV The IPEC main transformers have a low voltage rating of20.3kV. Therefore the main transformers are being subjected to over-excitation voltage above 105% design limits, as high as 111 % of rated. This over-excitation operation can result in breakdown of the transformer insulation on an extended period. (I will be contacting ConEd and NYP A system planning this week (7-18-05) to try to determine why these generator - transformer voltage arrangement was chosen.)
The transformer low side voltage rating needed to be addressed before proceeding with the fabrication of the replacement TPEC Unit 2 main transformers.
The DGA test results show some minor thermal heating issue, which have stabilized since the cooling system has been place in manual run.
Main Transformer 22 has significance N2 leak, which cannot be repaired without a unit shutdown.
The units were evaluated by ABB as part of the power uprate project in 2002. This evaluation made a number of recommendations. One of the recommendations made by the ABB report was to install additional cooling. This recommendation was not implemented based a decision purchase and replacement units.
Based on a review of condition of all the ENN Fleet main transformers it is my conclusion that the IPEC Unit 2 main transformers are at the highest risk with the Fitzpatrick units next. IPEC Unit 3 has the similar operating issues as Unit 2 but due to the unit's MV Ar capability generator terminal voltage and total MVA less. The limit on the total MV A output and does not require a high a generator terminal voltage.
IPEC00071776 IPEC00071776
A more detailed review of the condition of the fleet main transformer is being developed and will be issued by the end ofJuly 2005.
IPEC00071777 IPEC00071777