ML12052A295

Email from R. Martin, NRR to P. Boyle, NRR Na Draft RAIs - Fuel & Reactor Systems

ML12052A295
Person / Time
Site:	North Anna
Issue date:	09/13/2011
From:	Patrick Boyle Office of Nuclear Reactor Regulation
To:	Martin R Office of Nuclear Reactor Regulation
References
FOIA/PA-2011-0357
Download: ML12052A295 (1)

Text

Boyle, Patrick From: Boyle, Patrick ý Sent: Tuesday, September 13, 2011 12:31 PM To: Martin, Robert

Subject:

RE: NA draft RAIs - Fuel & Reactor Systems CEA - Control Element assembly, term normally from B&W and CE plants. Westinghouse calls these RCCA -

Rod Control Cluster Assembly. It's possible that they have some Westinghouse and some BW, however, control rods are a long term (excess of 10 years) component in a PWR, since they are fully withdrawn from the core during normal operations, so I would be surprised if they had a mix, but it's not impossible. A BWR shapes the flux with control rods and needs to replace several control blades every outage.

DNBR - Departure from Nuclear Boiling Ratio is the ratio of actual localized temperature to the temperature at which nucleate boiling occurs. Related to the Fq (peak power) TS CHF - Critical Heat Flux is a measure of heat in the assembly that will produce localized boiling - related to the FNDH (enthalpy rise) TS.

The two terms are related, but have different and specific meanings in thermo-hydraulic space.

Let the big guys figure out what terms they want to use, I thought these definitions might help with your questions.

My direct fuel handling experience has been limited to TRIGA fuel, movement and inspection. My PWR fuel handling experience, at a Westinghouse plant, has been limited to riding the refueling bridge in the spent fuel pool during off load and reload, including calling the moves into the control room. I have also done some viewing of video recording for core verification during reload and review of tapes of suspect assemblies, but only for general integrity purposes as I was not VT-2 qualified. I have never observed binocular checks. You can do this with a clear bottomed box partially submerged in the pool to eliminate surface reflections and distortion, but the problem comes from the tremendous heat being produced by spent assemblies and the associated thermal distortions and Cherenkov glow from the gamma emissions.

From: Martin, Robert Sent: Tuesday, September 13, 2011 11:06 AM To: McCoy, Gerald; Hiland, Patrick Cc: Glitter, Joseph; Kulesa, Gloria; Boyle, Patrick; Khanna, Meena

Subject:

NA draft RAIs - Fuel & Reactor Systems 1D