ML052990027
| ML052990027 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  (NPF-011, NPF-018) |
| Issue date: | 10/25/2005 |
| From: | Satorius M Division Reactor Projects III |
| To: | Crane C Exelon Generation Co, Exelon Nuclear |
| References | |
| Download: ML052990027 (2) | |
See also: IR 05000373/2005010
Text
October 25, 2005
Mr. Christopher M. Crane
President and Chief Nuclear Officer
Exelon Nuclear
Exelon Generation Company, LLC
4300 Winfield Road
Warrenville, IL 60555
SUBJECT:
ACKNOWLEDGMENT OF RESPONSE TO FINAL SIGNIFICANCE
DETERMINATION LETTER DATED SEPTEMBER 7, 2005, FOR A WHITE
FINDING AND NOTICE OF VIOLATION (NRC INSPECTION REPORT
05000373/2005010; 05000374/2005010), LASALLE COUNTY STATION,
UNITS 1 AND 2
Dear Mr. Crane:
The NRC acknowledges the receipt of your letter dated October 7, 2005. In your letter, you
concurred with the violation and provided a rational for its occurrence. You indicated that the
cause of the violation was a modification made to inhibit Emergency Diesel Generator breaker
closure on a bus lockout condition during an accident that re-introduced the single point
vulnerability into the CT circuit. A contributing factor was the various programmatic reviews that
failed to identify the single failure vulnerability because these reviews were limited in scope and
did not evaluate the system protection logic. Your letter also provided information about
enhancements made to the modification program over time that would preclude the occurrence
of this type of error.
The NRC is currently reviewing your response. After our review is completed, we will use the
response to determine the scope of the supplemental inspection mandated by the Reactor
Oversight Program in response to the White finding. We anticipate conducting this inspection
in the first quarter of 2006.
C. Crane
-2-
If you have any questions regarding this letter, please contact Bruce Burgess, Chief, Reactor
Projects Branch 2 at (630) 829-9629.
Sincerely,
/RA/
Mark A. Satorius, Director
Division of Reactor Projects
Docket Nos. 50-373; 50-374
DOCUMENT NAME: G:\\Lasa\\ML052990027.wpd
To receive a copy of this document, indicate in the box:"C" = Copy without enclosure "E"= Copy with enclosure"N"= No copy
OFFICE
RIII
RIII
RIII
NAME
B. Burgess
K. OBrien
M. Satorius
DATE
10/24/05
10/24/05
10/25/05
OFFICIAL RECORD COPY