Radioactive Aerosol Standards - Aerosols: Measurement, Dosimetry, and Health Effects - page 535

These tests are carried out at the request of users, scientiic or industrial manufacturers, either
French or foreign, to deine the performance of a given aerosol radioactive contamination monitor
in order to obtain type approval for the monitor by the IPSN Centre Technique d'Homologation
de l'Instrumentation de Radioprotection (CTHIR). Tests can also be used for deining prototypes
manufactured by industry. There are two types of tests: static tests, performed with solid standard
radioactive sources; dynamic tests, performed on the ICARE bench. This bench, continuously
generating natural and artiicial radioactive aerosols, calibrated for size and activity, enables
the true performances of the radioactive aerosols monitors to be deined under normal operat-
ing conditions. The true measurement eficiency is obtained by sampling and measuring, in real
time, the activity of aerosols labeled with 239 Pu and/or 137 Sr. The inluence of the natural activity
upon the artiicial activity measurement channels is determined by aerosols bearing radon decay
products whose concentration and attached fraction can be adjusted. Knowledge of the factor of
inluence of the natural activity and the type of treatment (algorithm) used on this monitor makes
it possible to calculate the monitor detection threshold under normal operating conditions. The
dynamic test procedure described in the document has been adopted as an international standard
by IEC in 1996.
Installation for performing testing of continuous air monitors (CAMs) for alpha-radioactive
nuclides is described by Grivaud et al. (1998). These instruments must have adequate sensitivity
to alert potentially exposed individuals that their immediate action is necessary to minimize or
terminate an inhalation exposure.
The air monitor test facility at the Lovelace Respiratory Research Institute (formerly the
Inhalation Toxicology Research Institute) has been developed for U.S. Department of Energy and
used to test performance of prototype and commercially available alpha CAMs, personal air sam-
plers, and ixed area ilter samplers. Test conditions for these instruments are consistent with 1995
recommendations of IEC (Hoover et al., 1998).
The facility includes a station for instrument receipt and inspection, a test bench for determining
detection eficiency and energy response for alpha-radioactive radio nuclides using point-type and
area-type electroplated sources and ambient radon progeny; an inline aerosol delivery for testing the
internal collection eficiency of sampling heads with luorescent and other inert aerosols; an aerosol
wind tunnel in which inert aerosols can be used to evaluate the inlet and transport eficiency of
sampling probes and aerosol collection devices; systems for testing the normal response of monitors
to ambient radon progeny aerosols or providing aerosols of plutonium or uranium with or without
radon progeny aerosols and interfering dusts to air monitor under different conditions of concentra-
tion and time. The Lovelace Air Monitor Test Facility is similar, but not identical, to the EPICEA
laboratory Institute which belongs to ISPN.
Many different types of tests on air monitors were provided at this facility.
Static tests are performed using clean collection substrates with no sampling low to verify
proper reports of background in the absence of radioactive source. For this purpose the standard
radioactive source with traceability to the National Institute of Standard and Technology was used
to determine the overall detection eficiency for uniformity distributed sources.
Dynamic tests of collection eficiency of in-line sampling heads were provided by connecting
them to an aerosol generation system with parallel sampling ports for head and in-line reference ilter.
Dynamic tests with radon progeny were performed to evaluate the inluence of natural radioac-
tivity on the ability of CAMs to report correctly the absence of plutonium in the presence of a low
concentration of radon decay products when no plutonium is present.
Dynamic tests with radon progeny and artiicial radioactivity were provided with higher con-
centrations of radon progeny (up to 370 Bq m −3 in the current system) in the special radioactive
aerosol generation system located in the Lovelace plutonium test facility.
Tests for system performance in the presence of interfering dusts were provided because the
inluence of salt dusts with proper detection of actinide aerosols that may be released from the
storage of transuranium wastes in underground salt formation is of special concern. To evaluate