- Magpie Country Nukes Headliner Nuclear Issues News Brief
From Japan Criticality accident at Tokai uranium processing plant 21st
- The union of the employees of JAERI (Japan Atomic Energy
Research Institute, see ##th Report) worked out an independent estimation
of the total radiation dose at 17 monitoring points around the JCO Tokai
accident site. The result of their calculation was reported in Mainich
Newspaper on 16 and 17 October nationwide. It unequivocally shows that
evacuation of at least 600m radius z one (rather than the actual evacuation
of 350m zone) should have been encour aged, as it was revealed that the
anual dose limit of 1mSv had been reached even at a 400m point.
- It has also been revealed that the Government's emergency
responce unit (hea ded by the Prime Minister Obuchi) was about to issue
the evacuation order fo r 500m zone, but it was not issued since it was
after midnight (i.e. early h ours of 1 Oct) and it was raining (so a panic
could easily be caused). As a result, the population in 350m to 600m zone
was left in the neutron bombard.
- According to NHK (national TV/radio network) news on
18 October, STA (Scienc e and Technology Agency of the Japanese Government)
plans to extract the ura nyl nitrate solution that remains in the precipitation
tank in which the fis sile uranium elements went criticial. However, the
dosage rate in the reconv ersion test building in which the tank in question
is installed is still as high as over 10mSv/h (gamma, or gamma + neutron?).
Anybody who approaches th e tank will be dosed with unacceptably high amount
of radiation. STA says th ey will sort out an operational procedure with
certain time limit so that ra d-exposure can be minimized, and hopes to
carry out the operation before the end of this week. They declines to say
- Radiochemically speaking, retrieving the solution is
of crutial significance in understanding the nature and extent of the accident.
Qualitative and quan titative analysis of the fission products (such radionuclides
as barium, ru thenium, molybdenum, cerium, etc) that are contained in the
solution will re nder an exact estimation of the number of nuclear fissions
(thus the number of neutrons and energy generated).
- How many people must be exposed how much to the very
dangerous level of radi ation just in order to obtain several decilitters
of the solution, which is a sufficient amount for the analysis, is a hard
question, both in terms of science and of justice.