U.S. government officials, in private sessions on Capitol Hill [on Friday, March 18], repeatedly declined to give details of radiation measurements at the stricken Japanese nuclear complex, saying the situation is shrouded in a fog of war." Separately, the Obama administration said ... "miniscule quantities" of radiation from the Japanese nuclear accident were detected Friday at a monitoring station in Sacramento, Calif., a day after similar traces of radiation were detected in Washington state. The administration said the levels of the radioactive isotope xenon 133 were approximately equivalent to one-millionth the dose received from the sun, rocks or other natural sources. The Obama administration's reluctance to detail in public what it is learning from radiation-detection operations around the damaged Fukushima Daiichi complex in Japan ... comes after statements Wednesday by the head of the U.S. Nuclear Regulatory Commission that painted a grimmer picture of the nuclear crisis than Japanese officials had offered, and suggested that the U.S. didn't trust the information coming from the Japanese government.