- STA Admits General Public Exposure To Neutron Radiation
Dose Estimation Publicized And Registration Of Exposed Residents For Long-Term
- The Tokai Criticality Accident Investigation Committee
today presented the r esults of the analysis of the uranium solution samples
obtained from the acc ident site (see 22nd report). According to the calculation
by the Japan Atom ic Energy Research Institute (JAERI), the first 25 minute
of the criticality , which eventually lasted nearly 18 hours, yielded a
total 75mSv exposure at the distance of 80m from the ground zero. (This
is the minimam distance from the precipipitation tank where the uranium
went critical to the JCO site bou ndary).
- It is estimated that as much as 48% of the total energy
emmission took place during the first 25 minutes of the criticality.
- The cumulative doses for the first 5 hours (i.e. before
the residents evacua ted) are estimated by STA at 110mSv at 80m point,
and 1.4mSv at 350m point ( neutron plus gamma, roughly at 10:1 proportion).
This can mean that almost a ll the members of the general public around
the plant had got the dose over annual limit (1mSv) before they escaped.
- STA (the Science and Technology Agency of the Japanese
Government) says that the doses are of harmful levels in a long term, and
admits that there is a h igh possibility that the members of the general
public around the site were exposed to considerable doses.
- Oh, what a decent expression!
- Also publicized today are the doses suffered by the JCO
workers (other than those of the rush platoon) on site on the day of the
accident: between 64mSv (max) and 0.6mSv (min). As reported earlier, the
rush platoon members were d osed with the maximum of 120mSv.
- The seven construction workers, who had been working
outdoors on a ground ad jacent to the JCO plant (not "golf course"
as incorrectly reported earlier), were dosed with between 15mSv (max) and
- From the data newly disclosed by JAERI/STA, Dr Jinzaburo
Takagi estimates th e number of the fission at around 2.5E+18, and the
weight of U235 that went into chain reaction at around 1mg. He reserves
a possibility that the figure s may be larger if we consider the problems
in the method of taking samples (see 22nd report).
- Earlier on 29th of October, the local governments (namely
Tokai-mura and Nak a-machi, with the supervison of Ibaraki Prefecture)
started to register the affected people. Initially 120 evacuees were registered,
and a hundred more people are expected to register, not only the residents,
but also the passer s-by who happened to be in the neutron radiated areas
on the day of the acci dent. The prefecture administration say that those
registered will be monito red over 10 years period for their health conditions.
- The residents of the radiated zone are expressing fear
and anxiety over the state of affairs. Media reports also oscilate between
"no worries" and "canc er in ten years". Discriminations
not only against the farm and sea products of Tokai region, but also against
the people are already being reported, as it happened very badly against
the surviving victims of Hiroshima and Nagasaki.
- One big question is what lessons we ever had in the last
54 years of nuclear age...
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= Magpie Country Nukes Headliner editor: Dr K. Hosokawa fax: +81-952-288709
email: <email@example.com snail mail: Faculty of Agriculture,
University of Saga, 840-8502 Japan