ML120520102

Email, Courtesy Notification of 50.54(f) Letter Regarding Thermal Conductivity Degradation (TAC No. M99899)

ML120520102
Person / Time
Site:	Diablo Canyon
Issue date:	02/21/2012
From:	Joseph Sebrosky Plant Licensing Branch IV
To:	Baldwin T, Soenen P Pacific Gas & Electric Co
Sebrosky J, NRR/DORL/LPL4, 415-1132
References
TAC M99899
Download: ML120520102 (1)

Text

From: Sebrosky, Joseph Sent: Tuesday, February 21, 2012 7:02 AM To: Soenen, Philippe R; Baldwin, Thomas (DCPP)

Cc: Paige, Jason; Wang, Alan; Peck, Michael; Micewski, Laura

Subject:

info: Courtesy notification of 50.54(f) letter regarding thermal conductivity degradation Mr. Soenen and Mr. Baldwin, The purpose of this email is to make you aware of an issue related to thermal conductivity degradation.

On Thursday, February 16, 2012, the Nuclear Regulatory Commission (NRC) staff issued 10 CFR 50.54(f) letters to plants that use Westinghouse realistic emergency core cooling system (ECCS) methods (ASTRUM or CQD) and have a peak cladding temperature (PCT) greater than 2000 degrees F. The letters required that the plants listed below provide information regarding the effect of a potentially significant error, as defined in 10 CFR 50.46(a)(3)(i), associated with thermal conductivity degradation (TCD), on peak cladding temperature in the Westinghouse Electric Company-furnished realistic ECCS evaluation models, to enable the NRC staff to determine whether the affected plant licenses should be modified, suspended, or revoked. A list of plants that received the 10 CFR 50.54(f) letters and ADAMS Accession number is below:

Beaver Valley, Units 1 and 2 - ML120400672 DC Cook, Units 1 and 2 - ML12041A384 Kewaunee - ML120410195 Byron, Unit 2 / Braidwood, Unit 2 - ML120410134 Catawba, Units 1 and 2 - ML12044A018 McGuire, Units 1 and 2 - ML12044A019 You are receiving this information for awareness since Diablo Canyon uses the Westinghouse realistic ECCS methods (ASTRUM or CQD) but have a PCT less than 2000 degrees F.

Information Notice 2011-21, Realistic Emergency Core Cooling System Evaluation Model Effects Resulting From Nuclear Fuel Thermal Conductivity Degradation, provides additional technical details on this issue.

Please let me know if you have any questions.

Sincerely, Joe Sebrosky Project Manager (Diablo Canyon Power Plant)

Nuclear Regulatory Commission Division of Operating Reactor Licensing joseph.sebrosky@nrc.gov 301-415-1132