The U.S. agency charged with protecting America's nuclear weapons has deployed a team of stateside supercomputer experts to gauge the radiation risks posed by the nuclear crisis in Japan.
In addition to safeguarding the nuclear stockpile, the National Nuclear Security Administration is regarded as the chief responder to any radiological incident within the United States. As such, some experts say NNSA is uniquely positioned to aid in Japan, where explosions rocked a nuclear power plant following an 8.9 magnitude earthquake on Friday.
The ability of the agency, which is part of the Energy Department, to arm decision-makers with accurate information about the extent of the nuclear threat largely rests on supercomputers.
NNSA officials on Monday said they have activated the National Atmospheric Release Advisory Center -- staffed by computer scientists, nuclear scientists and meteorologists -- to provide U.S. authorities with real-time estimates on the spread of radioactive materials in the atmosphere. The squad's specialists plug data in to supercomputer algorithms on radiation doses, exposure, hazard areas, meteorological conditions and other factors to produce predictive models.
"NNSA has probably the world's premier set of codes that are capable of doing advanced simulations on all things nuclear," said Stanley C. Ahalt director of the Renaissance Computing Institute in the Research Triangle area of North Carolina. "Not only do they have codes that are capable of understanding the degrading of the nuclear stockpile, but also that are capable of simulating, at the physical level, very sophisticated interactions between materials that are necessary for reactors to operate."
The crew is located in California at the Lawrence Livermore National Laboratory, which houses the BlueGene/L and Dawn supercomputers, ranked Nos. 12 and 16 on the biannual list of the world's most powerful supercomputers. A machine in China holds the No. 1 spot on the Top 500 list, but, Ahalt said, "the Chinese don't have anywhere near the experience in working on these types of problems that NNSA has."
Shaking caused by Friday's quake and a subsequent tsunami knocked out cooling systems at the Fukushima Dai-chi nuclear complex, which has led to some melting in reactor cores. "Each of these reactors was constructed at different times with different materials and is at different levels of aging," Ahalt said.
Now, Japanese officials are rushing to cool down fuel rods via manual methods, such as spraying water into the reactors, to prevent a meltdown, which likely would have lasting, deadly effects.
Destruction on the scale of the 1986 Chernobyl accident that leaked massive amounts of radioactive materials into the environment is not expected. "But the residual heat is still captured in those uranium rods," Ahalt noted. NNSA has the tools to form assumptions on how the core material might degrade, he said.
NNSA officials are in communication with Japanese officials, the U.S. agency said on Monday.
"Senior officials and technical experts from the Department of Energy continue to be in close contact with other agencies as well as with our Japanese counterparts as we work to assess what is a very serious and fluid situation," NNSA spokesman Damien LaVera said. "The United States will continue to work closely with the Japanese government and will provide whatever assistance they request to help them bring the reactors under control."
State Department officials on Monday advised U.S. citizens in Japan to heed the directions of Japanese authorities in vacating the affected area.
"Japan's Nuclear Industrial Safety Agency has recommended that people who live within 20 kilometers of the Fukushima Nuclear Power Plant evacuate the area immediately," said John V. Roos, U.S. ambassador to Japan. "We are confident that the government of Japan is doing all it can to respond to this serious situation."
On Sunday, the Nuclear Regulatory Commission, which polices U.S. commercial nuclear power plants, said American officials do not foresee dangerous amounts of radiation reaching the United States.
"All the available information indicates weather conditions have taken the small releases from the Fukushima reactors out to sea, away from the population," NRC officials said in a statement "Given the thousands of miles between the two countries, Hawaii, Alaska, the U.S. Territories and the U.S. West Coast are not expected to experience any harmful levels of radioactivity."