The National Atmospheric Release Advisory Center provides atmospheric plume predictions so that emergency managers can decide whether to take protective action after potential disasters, according to the group's website.
It provides real-time analysis of nuclear, radiological, chemical, biological and natural emissions.
The center is providing ongoing models based upon a variety of scenarios, both real world and speculative, following last week's deadly earthquake and tsunami, nuclear security administration spokesman Damien LaVera said.
Several explosions have been reported at Fukushima Daiichi Nuclear Power Station in the wake of the natural disaster, leading to concerns of a potential nuclear catastrophe, according to the U.S. Nuclear Regulatory Commission.
The Department of Energy has sent two experts to Japan -- an emergency response representative and a nuclear engineer who speaks Japanese -- to assist the department's other team members on the ground, LaVera said.
The Nuclear Regulatory Commission has also been in close contact with Japanese officials and sent several experts, he said.
The commission has not found any evidence that dangerous levels of radiation from the reactions will reach U.S. territory, but the Livermore atmospheric center is looking at how wind changes or rain could affect the spread of nuclear materials in Japan.
"(The center) has been activated to provide the U.S. government with a predictive modeling capability to analyze a variety of potential situations," LaVera said.
The National Atmospheric Release Advisory Center in Livermore also assisted with the 1986 Chernobyl nuclear power plant disaster and the 1979 Three Mile Island accident in Pennsylvania, plus it was activated during the 1991 Kuwaiti oil field fires and the 1993 Richmond sulfuric acid cloud.