ASN Report 2015

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Gamma radiography
Serious accidents abroad
Gamma radiography accidents in France have remained
limited in number and consequences since March 1979,
when a worker had to have a leg amputated after having
picked up a 518 GBq source of iridium-192 and put it in his
pocket. This incident had led to a tightening of the regulations
in effect at the time. ASN continues to keep itself informed of
significant accidents around the world which have had major
deterministic effects. Recent examples brought to ASN’s
attention include:
• In 2015, in Iran, two operators were exposed to an effective
dose of 1.6 and 3.4 gray (Gy) respectively. The gamma ray
projector source ( 192Ir of 1.3 TBq) became disconnected
and remained blocked in the guide tube without the
operators realising it. The operators then spent the night in
their vehicle near the guide tube and the source.
• In 2014 in Peru, an employee was exposed to 500 mSv
whole body and 25 Gy on the left hip when he moved a
guide tube and a collimator without realising that the source
was disconnected from the remote control cable and had
remained in the collimator ( 192Ir, 1.2 TBq, 30 minutes of
exposure).
UNDERSTAND
CROSS-SECTIONAL VIEW of a gamma ray projector
• In 2013, in Germany, an employee of a non-destructive testing
company was exposed to more than 75 mSv whole body and
10 to 30 Gy at the extremities (hands) while attempting to
release a source from a guide tube.
• In 2012, a Peruvian employee was admitted to Percy hospital
in Clamart following exposure of 1 to 2 Gy (whole body) and
of 35 Gy to the hand (70 Gy at the fingertips) after handling
a guide tube with his bare hands, without first checking the
position of the source. The industrial radiographer required partial
amputation of the fingers of the left hand.
• In 2011, 5 Bulgarian workers were admitted to Percy hospital
in Clamart for major treatment following irradiation of 2 to 3 Gy
owing to an error in the handling of a gamma ray projector, from
which they believed the source had been removed.
• In 2011, in the United States, an apprentice radiographer
disconnected the guide tube, noticed that the source was
protruding from the source applicator and tried to push the source
into the device with his finger. The estimated dose received at the
extremities is 38 Gy.
Safe position Open position
Shielding Source Plug in safe
position
Direction of
source projection
Plug in open
position
Guide tube
342 CHAPTER 10: INDUSTRIAL, RESEARCH AND VETERINARY USES AND SOURCE SECURITY
ASN report on the state of nuclear safety and radiation protection in France in 2015