Questions and answers for the concerned public

A1. Greenpeace conducted an independent investigation beginning on Oct. 3^rd. On 7 October the results of its investigations into environmental radioactivity around the Tokai-mura uranium conversion site, 130km north of Tokyo were released. It should be noted that radiation levels around the plant have now returned to normal although the plant itself is heavily contaminated.

Q2. WHAT WERE THE PRIMARY FINDINGS OF GREENPEACE’S INVESTIGATION?
A2.

Greenpeace began measuring radioactivity around the Tokai-mura site on the late afternoon of Sunday October 3^rd. Within hours we discovered that background radiation levels were not "back to normal" as stated by the Japanese government but in fact were up to five times higher, at 0.54 microSieverts per hour. The sampling team from Greenpeace Netherlands, and Germany, as well as Japan, measured these levels approximately forty metres from the source of the radiation - the uranium enrichment facility where the accident occurred. This happens to be on a public highway, including a pavement where people walk and cycle. These levels exceeded maximum permissible levels for public exposure, and in many other countries such as Germany or the Netherlands, would result in immediate closure of the area. A gradual decrease in radiation levels have since returned this area to normal.

Greenpeace sampled soil and plant material from around the JCO uranium fuel conversion facility. Samples were taken during Sunday 3^rd and Monday 4^th October, and sent for analysis at Rikkyo University in Tokyo. Levels of Iodine-131 and Iodine-133 were detected. Calculating back to the time the criticality stopped, around 4.30am on Friday, the levels were 1182 Bequerels per kilogram for the short lived isotope Iodine-133. These levels were found in the immediate vicinity of the plant.

Conclusions:

2. No heavy elements appear to have been released by the accident, these are still in the tank.
3. Elements released were volatile substances in the form of a fine gas or aerosol. Upon entering the environment, especially since for a period of the accident it was raining, the material landed on the ground in the immediate vicinity of the plant, definitely within hundreds of metres, but probably also within a few kilometres.

The other major component to Greenpeace’s radiation monitoring was to seek to identify levels of neutron radiation emitted during the accident. Such radiation, which is deeply penetrating, travels in a straight line from source for hundreds of meters, passing through almost everything, but losing energy the longer it travels, and the more objects it passes through. Greenpeace’s method was to measure for the radioactive isotope Sodium 24--this is created when the isotope Sodium-23 is activated by neutrons. Greenpeace obtained samples of domestic table salt from two houses around the JCO uranium facility.

This cooking salt received the full neutron release during the accident. One large 2 kg sample was measured in a laboratory in Rikkyo University. The sodium 24 levels measured were then used to calculate levels of neutron radiation at the end of the nuclear accident, Friday 4.30AM, based upon the half-life decay (the period in which a particular radioactive element will lose half its mass) period of sodium24, which is 15 hours. The calculations made gave a figure of 6280Bq/kg, with an error margin of plus/minus 319Bq. Using this figure we can calculate the neutron yield or flux energy released during the 20 hours of the criticality which was 1 mSv per hour. This then has been cross referenced with the actual measurements made by the Japanese authorities.

A3. On the basis of these results, Greenpeace believes that within at least a 500 meter distance, hundreds of people would have been exposed to harmful neutron radiation. This compares with the Japanese government’s assurance that 49 people were exposed to radiation.

According to Professor Wolfgang Koehnlein, radiation biologist at University of Muenster in Germany, who analyzed Greenpeace’s figures, a dose of 20 mSV to people in the neighbourhood could cause longterm damage. The 20 mSv figure compares with a maximum recommended yearly rate of 1 millisievert. Within this range of exposure, many people will have received a dose less than this, perhaps half their annual dose. On the other hand, a number of people may have received a dose of many times their annual dose, tens and tens of years even.

A4. Levels of radiation and radioactive contamination measured around the plant demonstrate that this was not a release on the same scale of the 1986 Chernobyl reactor accident but was still significant. The International Atomic Energy Agency have graded the Tokaimura accident a "5" on their accident scale, the same scale as the Three Mile Island reactor accident in the United States.

Most of the radioactivity remains inside the tank in the facility, at least 95%, Greenpeace estimate. A comprehensive environmental monitoring program is essential to accurately understand the dispersion and level of fallout. In terms of public health, there is no threshold below which radiation is considered safe. However, levels of radioactive fallout measured do not pose an immediate health risk but may effect public health over the medium to longer term. From the measurements taken by Greenpeace, the effects of the radiation will almost entirely be felt by those people living in the immediate vicinity of the plant.

Neutron radiation is considered harmful to the building block of life human DNA cells, damage to which can seriously increase the risk of cancer and other health effects. Many of these diseases may occur years and years after exposure, thus a plan for long-term health monitoring is crucial.

A5. If you are a foreign national living in Japan, you have a particular opportunity to help prevent future accidents in Japan. Western nuclear trading states, especially Britain, France, Belgium the Netherlands, Australia, Canada and the United States, all assist Japan’s nuclear development. In particular, Greenpeace is battling to stop the UK, France and Belgium from providing any more fuel containing weapons-usable plutonium to Japan. Over 30 tons of plutonium in "mixed oxide" (MOX) fuel is due to be shipped back to Japan over the next ten years. Already Japan has 5 tons of plutonium stockpiled at facilities around the country, most of which is not by coincidence at Tokai-mura. We recommend that if you feel concerned about this you express your opinions to your Embassy in Tokyo.

Residents of the above countries should ask their governments for an explanation as to why they support Japan’s nuclear program, especially its plutonium program, and urge them to stop before Japan suffers an even more serious accident than that which occurred at Tokai-mura on September 30^th.

A6.

**** If you feel you may be suffering from health problems related to the accident, go to your doctor or local hospital for advice.
****Contact the Science and Technology Agency of the Japanese Government and ask for access to more details. (T: 81 (0) 29-287-0830~2; F: 81 (0) 29-282-8962, 9 a.m. to 8 p.m.)
**** If you are against nuclear activities - let the government know by voting for an anti-nuclear candidate in the next elections.
****If you live near a nuclear facility, ask the local government what the evacuation and emergency plans are and when the last drill took place.

**** If you are planning to visit Japan contact authorities in your home country before you leave. Until more facts emerge on contamination levels, avoid going to the Tokaimura and the surrounding area.

A7. For foreign residents of Japan, below are some useful phone numbers for more information:

Hospitals

Tokyo Jikei Igakudaigaku Fuzokubyouin 03-3433-1111

Shouwa Daigaku Byouin 03-3784-8000

Teikyo Daigaku Igakubu Fuzoku Byouin 03-3964-1211

Juntendo Daigaku Igakubu Fuzokubyouin 03-3813-3111

Kokuritsu Byouin Tokyo Saigai Iryou Center 042-526-5511

Saitama Public Health Center (Prefectural office 048-824-2111)

Chiba consulting office 043-223-3884