NRC-03-0098, Oscillation Power Range Monitor Operability at Option III Plants
| ML033640581 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 12/22/2003 |
| From: | O'Connor W DTE Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-03-0098 | |
| Download: ML033640581 (2) | |
Text
William T. O'Connor, Jr.
Vice President, Nuclear Generation Fermi 2 6400 North Dixie Hwy., Newport, Michigan 48166 Tel: 734-586-5201 Fax: 734-5864172 DTE Energy-December 22, 2003 NRC-03-0098 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001
References:
- 1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF43
- 2) Letter from K. S. Putnam, BWR Owners' Group Chairman, to Document Control Desk, Washington D C, dated September 30, 2003 (BWROG-03047)
- 3) Letter from K. S. Putnam, BWR Owners' Group Chairman, to Document Control Desk, Washington D C, dated September 30, 2003 (BWROG-03049)
- 4) Letter from Jason S. Post, GE Nuclear Energy, Manager Engineering Quality and Safety Evaluations, to Document Control Desk, Washington D C, dated August 31, 2001 (MFN 01-046)
Subject:
Oscillation Power Range Monitor Operability at Option III Plants On September 30, 2003, the Boiling Water Reactor Owners' Group (BWROG) formally described its resolution of a reportable condition involving thermnal/hydraulic stability reload calculations using a generic curve (Reference 2).
At the same time, the BWROG informed affected utilities that the Nuclear Regulatory Commission (NRC) had asked for the remaining utility schedules for completing actions necessary to make their Oscillation Power Range Monitor (OPRM) operable (Reference 3).
USNRC NRC-03-0098 Page 2 Detroit Edison initially armed and declared its OPRM operable prior to startup from the seventh refueling outage in May of 2000. The OPRM has remained armed since that time to provide automatic reactor scram for detected thermal/hydraulic instability events. Since the time the OPRM was initially declared operable, it has been declared inoperable for several short intervals following receipt of notification of potential deficiencies in setpoints or other software parameters. However, even while considered inoperable, the OPRM remained armed to provide its automatic scram for any instability events it would detect. Currently, the OPRM is armed and operable with a cycle specific setpoint developed using a conservatively selected interim regional mode Delta Critical Power Ratio/Initial Critical Power Ratio Versus Oscillation Magnitude (DIVOM) curve. The selection of the interim DIVOM curve is based on a cycle specific figure of merit calculation performed in accordance with BWROG guidance as discussed in Reference 4.
Ultimately, Detroit Edison plans to adopt the Detect and Suppress Solution -
Confirmation Density (DSS-CD) when it adopts General Electric's Maximum Extended Load Line Limit Analysis-Plus (MELLLA+) initiative. This is currently under consideration for the eleventh or twelfth refueling outage at Fermi 2 (2006 and 2007, respectively). Until that time, Detroit Edison plans to maintain operability of the OPRM using an cycle specific setpoint based on an interim DIVOM curve.
Should you have any questions or require additional information, please contact Mr. Norman K. Peterson of my staff at (734) 586-4258.
Sincerely, cc:
H. K. Chernoff M. A. Ring NRC Resident Office Regional Administrator, Region mII Supervisor, Energy Operations, Michigan Public Service Commission