Commentary: Even low levels of radiation leakage a cause for concern

by Akira Tashiro, Executive Director of the Hiroshima Peace Media Center

One of the most massive earthquakes in human history, which unleashed a terrifying tsunami, hit eastern Japan on March 11. The 9.0 magnitude earthquake has caused the sort of devastation to the Pacific shores of Japan that reminds us of the destruction left in the wake of the atomic bombing of Hiroshima. To make matters worse, the Fukushima No. 1 nuclear power plant, run by the Tokyo Electric Power Company, suffered damage in the disaster and has leaked worrisome levels of radiation. The situation is growing more perilous as time passes.

When even a single reactor is in such a grave state, staving off a meltdown of the fuel rods is not an easy task. With three reactors as well as storage of spent nuclear fuel rods demanding such attention, the dire circumstances are unprecedented. The workers battling the troubled reactors and spent nuclear fuel, seeking to cool them down and prevent the situation from spiraling further downward, are performing their jobs at the personal risk of exposure to high doses of radiation. People all over Japan, indeed all over the world, are glued to the unfolding crisis, praying for the safety of the workers and that the worst-case scenario will not come to pass.

In the vicinity of Reactor No. 3, a radiation level of 400 millisieverts per hour has been detected. This corresponds to 400 times the level of permissible exposure per year for ordinary people. Even if radiation levels fall well below this, relief operations, such as searching for the missing and tending to the destruction caused by the earthquake and tsunami, will be hampered if the area of radioactivity grows wider. Rescue workers from overseas, including U.S. military personnel, must be sensitive to the danger of radiation exposure.

Though we tend to focus strictly on radiation levels, the possibility that fissionable materials, including cesium and iodine, may also be released is another concern. In the case of mixed oxide fuel containing uranium and plutonium (MOX fuel), it is very likely that plutonium would escape if those fuel rods melt. Even a small dose of this hazard could do damage if absorbed into the body.

It must be remembered, too, that one's susceptibility to radiation varies from person to person. Even if a certain level of radiation is within the permissible range, this does not necessarily mean that the level is safe for all. Infants and children are said to be particularly susceptible to the effects of radiation and avoiding exposure to even low doses of radiation is advised.

In follow-up research studies concerning A-bomb survivors in Hiroshima and Nagasaki, it has been gleaned that even low-level exposure to radiation received internally can affect the health of the human body. The Japanese government must be expected to make the most of the knowledge that has been accumulated at universities and medical facilities in Hiroshima and Nagasaki so that effective protective measures can be taken in response to this current crisis.

Ten years ago I visited the areas that suffered the effects of nuclear accidents at Chernobyl in the former Soviet Union and at the Three Mile Island nuclear power plant in the United States. The Chernobyl accident was the worst in history, and nearly half the nuclear fuel melted at Three Mile Island. The lessons I drew from interviewing a number of victims of these nuclear disasters and hearing the graphic accounts of their experiences are: authorities should promptly release accurate information, without concealing anything from the public; and they should protect the health and safety of local residents by evacuating them from a broad area near the crisis zone to minimize the possibility of exposure.

In these two nuclear accidents, the above actions were not performed adequately and the result was damage that became more sweeping. In order to avoid a similar disaster, the government and the other bodies involved should squarely face what Prime Minister Naoto Kan has called “the unprecedented peril for the nation” and assume that the worst-case scenario of a core meltdown may occur.

(Originally published on March 16, 2011)