----- Original Message -----
Sent: Thursday, August 01, 2002 8:15
PM
Subject: IAEA video of orphan source
recovery - Georgia
See IAEA video clip at http://www.iaea.org/worldatom/Press/Focus/RadSources/VideoClip/Georg06WM.wmv
or different format
at <http://www.iaea.org/worldatom/Press/Focus/RadSources/VideoClip/Georg06RM.rm>
.......a part of this was shown
on the TV news a couple of days ago -- particularly the tricky recovery shown
~15 sec into the film clip -- the men worked in quick relays of only about a
dozen seconds each, due to the VERY high radiation levels (probably in the
1000 rem/hr range ?).
The TV video had better
close-ups -- the source was so hot, it was cooking the snow around it, raising
little puffs of vapour..... (maybe this is posted somewhere on the web too
?)
How the heck did these things
end up lying around unshielded ? ...someone's practical joke ?
....thanks.
Jaro
----------------
Dear Jaro
About your last paragraph I'll tell you and to
those interested in emergency response and training the following story:
a) The Shielding of the Remnant Source Capsule in
Goiania
Reference: Aspects of the Initial and Recovery phases of
the Radiological Accident in Goiania, Brazil
J.J.Rozental, C.E. Almeida, A.H.Mendonca, International
Symposium On Recovery Operations in the Event of a Nuclear or Radiological
Emergency, IAEA, Vienna, 16-10 November 1989
The rotating metal assembly holding the remains of the 137
Cs source capsule was enveloped by a cloth bag and placed on a chair, as show
in the figure, which in turn, was taken to the Corner of the Health
Department courtyard (Departamento de Vigilancia Sanitaria, see
picture).
The Dose rates measured by JJR at the surface of the
bag were greater than 10 Gy/h (1000 rad/hr) and equal to 0.4 Gy/h (40 Gy/h) at
a distance of 1 metre. (original source 59 TBq (1375 Ci) in Sept.
1987).
The radiation levels in the nearest sidewalk reached
values of up to 30 mGy/h (3 rad/h) and the neighbourhood was quite
apprehensive, not only because of the external radiation field but
especially because of the possibility of the spread of contamination
through rain and the falling of the source from the chair.
JJR decided for immediate measures to shield the whole set
(chair + source) not only to reduce the exposure rates and therefore to
minimize the number of evacuated houses but also recognizing the depressive
state of local inhabitants.
The best solution thought of at the time was to place a
concrete sewer pipe over the chair, with the help of a truck, generally used
for civil engineering purposes, equipped with a crane. Some difficulties had
to be overcome during this operation, for instance:
the chair was behind a 2 metre wall and very close to it
(less than 20 cm away);
the pipe oscillated when lift;
the pipe had to be moved dowards slowly to prevent the
chair from turning over;
With the help of the Secretaries of the
Health and the Transport of the State of Goias, it was possible to select
experienced workers and after three hours traininig given by JJR in the
Department of Transport in similar Scenario, to be sure not mistakes could be
happen, successfully was conduct the above described steps.
The sewer pipe was then filled with concrete, from a
distance, pumping it through a hose over the wall. The whole operation was
completed in 30 minutes and the radiation levels in the street were reduced to
values less than 0.1 mGy/h (10 mrad/h).
In the following two weeks, the shielded source was
repacked, to reduce the exposure rates as its surface even further, and a few
days later was transferred to the storage site.
The decontamination of the courtyard was carried out over
15 days and the normal activities of the Health Departament were
resumed.
An estimated dose of 1.3 Gy was calculated for the
technician who received the bag, placed it on his desk and left it there for
some time, before removing it to the courtyard.
b) About the second topic Search in Republic of Georgia for Recovery of Radioactive
Sources
"During the operation, IAEA staff and international
experts followed survey routes together with Georgian radiation specialists. A
powerful radiation scanner capable of detecting a radiation source at a
distance of one kilometer was mounted on a vehicle. "
When it is the possibility to use vehicle, even in
routes of the difficulty access, this we did it in Brazil. My colleague Carlos
Nogueira de Oliveira, now Emergency Coordinator at IAEA is an expert.
In Goiania it was not so difficulty to take a
general spectrum to locate foci, because we conducted an aerial
survey during two days using detectors mounted in a helicopter, as
an adaptation of an established airbone geophysical survey technique, and my
colleague Paulo Barreto, Director of the Technical Cooperation Division at the
IAEA was responsible to carry out the measures.
Reference:
Barreto, P., da Fonseca, E.S., Aerodiometry survey of the
City of Goiania after the accident with Cesium 137, II General Congress on
Nuclear Energy, Rio de Janeiro, Brazil, April 1988
http://www.iaea.org/worldatom/Press/Focus/RadSources/VideoClip/Georgia_video.html
Search in Republic of Georgia for
Recovery of Radioactive Sources
Summary of June 2002 news clip produced by Vadim
Mouchkin and Petr Pavlicek, IAEA Division of Public
Information
Georgian emergency
response and rescue team are basically police officers. They have been
assembled in preparation for a hunt for radioactive sources believed to be
missing in Georgia. The task is not completely new to
them.
In February
2002, these emergency workers participated in the actual recovery of two
radioactive sources found abandoned in a forest.
In June the International Atomic Energy Agency
with experts from four countries supported the Georgian survey operation
designed to track down other so-called orphan radiation sources. A number of
IAEA Member States donated various types of sensitive radiation
detectors.