Safety_Series_041_1975 - gnssn - International Atomic Energy ...

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ANNEX I
SAMPLING, ANALYSIS AND REPORTING PROCEDURES [15]
INTRODUCTION
The selection of sam pling equipm ent, the method o f sam ple
preparation, and the m easuring instrum ents depends on the nature
and activity o f the radioactive m ateria l that may be relea sed to the
environm ent. In an econ om ica l p rogram m e the m ethods and
instrum ents used should be adequate to m eet the o b je ctiv e s, but they
should, in gen eral, be the sim plest that w ill enable this to be done.
The m aterials that may have to be m onitored include a ir, w ater,
foodstu ffs, vegetation, s o il, fishing gear. In m ost ca ses a r e p r e ­
sentative sam ple of the m aterial is collected and its activity is
m easured either at the point of collection or later in the laboratory.
Instrumentation m ust be provided for sam pling and for activity
determ inations.
AIR SAMPLING
Sam ples o f airborn e particulates are norm ally collected on a
filter using an air pump and a flow -m easu rin g d ev ice. A ch arcoa l
filter can be placed after the main filte r to co lle ct iodine. The
collected sam ples may be subjected to g ross beta activity m ea su rem
ents, radionuclide analysis, g a m m a -sp ectrom etric analysis,
p article size studies o r autoradiography. If gam m a-sp ectrom etry
is called fo r, the volum e o f air sam pled should be not le s s than
about 300 m 3, hence sev era l sam ples may be com posited to provide
sufficient activity. The sam pling system should be mounted in a
sh elter and the d isch arge point located in such a m anner that
recircu la tion o f the air is prevented.
C onsiderable judgem ent m ust be ex ercised in the selection o f the
air sam pling sites. In gen eral, the sam plers should be placed at
three sites of m axim um predicted g rou n d -level concentrations
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