ML072710085

Email from J. Trapp, NMSS to J. Kramer, NRR on LEFM- Nine Mile Unit 2

ML072710085
Person / Time
Site:	Nine Mile Point
Issue date:	02/04/2005
From:	James Trapp NRC/RGN-I/DNMS/NMSB1
To:	John Kramer NRC/NRR/ADES/DRA
References
FOIA/PA-2007-0255
Download: ML072710085 (1)

Text

FE%;ýng6lo's Manno's - LEFIM -'Nine'Mile Ohit-2' ~7~ngeos~rins -LEF -Nne ileUni 2Pagqe1 From: James Trapp To: John Kramer Date: Fri, Feb 4, 2005 12:57 PM

Subject:

LEFM - Nine Mile Unit 2 The issue we are reviewing is as follows:

Nine Mile Point 2 has a CALDON LEFM. The LEFM is used monthly to determine a heat balance correction factor for the normal flow nozzle feedwater flow measurement. After maintenance including replacing the pads between the probes and pipe on the LEEM, the heat balance determined the reactor was being operated at - .54% over its rated thermal power (18.7 MWtI3467 MWt licensed power). The licensee reduced power by 18.7 MWt. The resident staff was concerned because this delta power appeared to exceed the limits in the old (1980) Ed Jordan (AQED) memo regarding operating over rated thermal power. The licensee's procedures indicate that any thermal power adjustment of less than .67%

is acceptable and not reportable. The basis is that this is the normal uncertainty of the LEEM.

The resident staff/Region I DRS/NRR l&C staff are working on this issue (not an immediate concern because power has been reduced). It brings up some interesting questions regarding operating above the licensed thermal power level. Certainly there is know measurement uncertainty in the thermal power calculation. This uncertainty is addressed in the accident analysis (assume 2%overpower) and not by reducing actual reactor thermal power to account for these uncertainties. The licensee normal operates the reactor at best estimate rated thermal power not considering uncertainties.

More to follow.

CC: CC:

A. Randolph Blough; Brian Holian; Ed Knutson

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