NISA Warned Of Deadly Radiation At Fukushima Reactors
Fukushima Power Plant
EMF Protection Devices
Magnetic Field Detector
September 13, 2011 | By
Officials of the Nuclear and Industrial
Safety Agency warned of possible deadly levels of radiation
at the Fukushima No. 1 nuclear power plant if the venting of
pressure at a reactor was not conducted successfully.
The information was revealed in NISA internal documents
obtained by The Asahi Shimbun through the information
disclosure law. Http://Ajw.Asahi.Com/Article/0311disaster/Fukushima/AJ201109130229
One document was compiled by NISA officials at about 1
p.m. on March 12, one day after the Great East Japan
Earthquake, and concerned possible outcomes if pressure was
not released from the containment vessel of the No. 1
reactor. The document said failure to vent the reactor could
lead to radiation levels spiking to several sieverts within
the Fukushima plant site. An individual whose entire body
has been exposed to seven sieverts of radiation would likely
The NISA document indicates that government officials
were considering the possibility that no one would be able
to enter the plant grounds if venting was not conducted.
At the time the document was compiled, pressure within
the containment vessel of the No. 1 reactor reached 750
kilopascals, which greatly exceeded the pressure level the
vessel was designed to handle.
To prevent destruction of the containment vessel, TEPCO
workers tried to vent gas from the morning of March 12, but
they were not immediately successful in opening the valve.
The NISA document said, "If a situation should continue
in which venting is not possible, a large volume of
radioactive materials will be released about 10 hours later
(at 11 p.m.)." The document added, "Depending on weather
conditions, there is the possibility of extreme radiation
exposure within a range of three to five kilometers from the
The document was faxed to the Nuclear Safety Commission
of Japan at 2:02 p.m. on March 12.
However, from about 2:30 p.m., pressure within the
containment vessel began to decrease, and the specter of a
large volume of radioactive materials being released was
TEPCO subsequently announced that it had successfully
carried out the venting.
Radiation measurements near the main gate to the
Fukushima plant did not approach the extreme figures
included in the NISA document. The highest radiation level
recorded was 11.93 millisieverts per hour, recorded at 9
a.m. on March 15. That is the equivalent of about 0.01