The United States sent a special nuclear response team to Japan right after the Fukushima meltdown disaster started in March 2011, but Japan was slow to make use of radiation data from the unit, according to U.S. and Japanese government sources.
This dispatch of the Consequence Management Response Team was the first approved for an emergency outside the United States. The CMRT, affiliated with the National Nuclear Security Administration, a semiautonomous agency of the Energy Department, is tasked with dealing with nuclear accidents and terrorism in the U.S. by detecting and analyzing radiation contamination.
The Japanese government, however, did not acknowledge the significance of the team’s mission and failed to immediately utilize the initial data it provided for evacuating residents living around Fukushima No. 1.
In recent interviews, U.S. sources involved in making the decision to dispatch the team said that on March 14, 2011, three days after the crisis began, the White House’s National Security Council decided to send the CMRT to Fukushima Prefecture at the request of U.S. Forces Japan and the U.S. Embassy in Tokyo.
The CMRT is dispatched to nuclear disaster zones with the Aerial Measuring System, an airborne system using military aircraft to detect gamma rays from altitudes of about 150 to 700 meters and calibrate doses of radiation with the help of highly advanced analytical software.
The AMS technology was first developed in the 1960s in the context of the Cold War when the United States and the Soviet Union conducted atmospheric nuclear tests. Since the Sept. 11, 2001, terrorist attacks on the United States, its capability to deal with nuclear terrorism has been enhanced.
The U.S. military and embassy requested the team’s dispatch as U.S. forces were engaged in the Operation Tomodachi (Operation Friendship) relief mission in the early weeks after the nuclear disaster, which was triggered by the March 11, 2011, Great East Japan Earthquake and tsunami.
The AMS data “helped confirm that there was no significant threat to the health and safety of the people” at U.S. bases in Japan, one U.S. government source said. “So I think that was the primary reason” for the special team’s dispatch, the source said.
According to this source, AMS operations concerning Fukushima No. 1 confirmed there was no fire in reactor 4’s spent-fuel pool, which senior officials and scientists of the U.S. administration were seriously worried about in the first week of the crisis.
The CMRT, consisting of 33 scientists and engineers, arrived at Yokota Air Base on March 16 from Nellis Air Force Base in Las Vegas and initiated test flights within 12 hours of arriving, according to an NNSA senior official. The CMRT conducted the first round of AMS operations from March 17 to 19, using two U.S. military aircraft.
The AMS flight operations over Fukushima were conducted around 100 times totaling 525 flight hours until the CMRT left Japan on May 28, 2011, an NNSA official said.
The CMRT provided radiation data from the first round of AMS operations to the Nuclear and Industrial Safety Agency, then Japan’s nuclear regulatory body, and to the Education, Culture, Sports, Science and Technology Ministry from March 18 to 20 via the Foreign Ministry.
These initial data, however, were not effectively used to make decisions about the early evacuation of residents around the plant, several Japanese sources reiterated recently.
Yukio Edano, then chief Cabinet secretary, said: “We did not get any briefing (about the AMS flights from lower-level officials). At my level, we did not go into any detail (about the operations).”