A chapter of the Laboratory’s storied history has closed at Technical Area 18. The Godiva Critical Assembly, or Godiva IV, was successfully disassembled in preparation for shipment to the Nevada Test Site. The work was the culmination of an effort that began in December 2004 and involved a team of 14 highly trained critical-assembly operators, criticality safety professionals, fissionable material handlers, nuclear material custodians and radiation protection personnel.
The Godiva Critical Assembly is one of three remaining fast burst reactors in the United States and was one of the most active assemblies at TA-18. A fast burst reactor is a prompt critical mass of highly enriched uranium metal designed to produce very intense, very short bursts of fission neutrons. The assemblies are used for lethality testing of weapon components, benchmarking weapons calculations and exploration of basic nuclear parameters of fissioning systems.
The current Godiva assembly, the fourth in the Godiva series at Los Alamos, is comprised of a stack of six interlocking uranium rings and plugs that are held together with high strength steel clamps. Assembly and disassembly of the fuel requires the use of a hydraulic press to compress the uranium and steel loading rings to remove and reattach the clamps. Concerns were raised during the planning stages of this project that the rings could be broken or could be stuck together making disassembly extremely difficult.
Disassembly was done at TA-18 with personnel in full anti-contamination clothing and respiratory protection. The work was completed in five days once approvals were obtained to begin disassembly.
This task is one of the efforts underway to pack all of the nuclear materials at TA-18 for shipment to the Nevada Test Site where a facility is being designed to re-establish the TA-18 mission.
“I want to emphasize the great teamwork that went into this very sensitive operation,” said David Loaiza of Advanced Nuclear Technology (N-2). “With incredible coordination the team was able to get past many internal and external hurdles to accomplish this difficult task.”
