National Nuclear Security Administration
April 28, 2005
The Honorable A. J. Eggenberger
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, N.W.
Washington, D.C. 20004
Dear Dr. Eggenberger:
Your July 9, 2003, letter required a report on resolution of in-core temperature monitoring system (ITMS) issues at Los Alamos National Laboratory (LANL) Technical Area (TA)-18. Although discussions between your staff, the Los Alamos Site Office staff, and the LANL staff took place, a report was not provided prior to your May 21, 2004, letter that required a briefing on several LANL safety issues including the ITMS. On July 8, 2004, LANL briefed the Board on the decision not to implement the ITMS. This decision was based on the fact that none of the planned remaining critical assembly operations will challenge the 25 Rem off-site evaluation guideline. The challenge to the off-site guideline is what drove the need for the ITMS to be a safety class engineered control. The fact that none of the planned critical assembly operations will challenge the off-site evaluation guideline, combined with the very limited use of the facility results in minimal risk and hence, allows operation of the critical assemblies without the ITMS. The National Nuclear Security Administration has completed the actions identified under this commitment and proposes closure of the commitment.
Everet H. Beckner
for Defense Programs
cc: M. Whitaker, DR-1