Role of the Radionuclide
Metrology Laboratory in
organization of the interlaboratory
comparisons for the measurement
of activity (Becquerel)
Maria Sahagia, Anamaria Cristina
« Horia Hulubei » National Institute of R&D
for Physics and Nuclear Enginnering,
1 . Introduction
The Laboratory of Radionuclide Metrology (RML) from IFIN-HH is the laboratory which
detains the primary Romanian standard of activity, designated by the Romanian Bureau
of Legal Metrology (RBLM) for the participation at the activities of the International
Committee of Measurements and Weights in the accomplishment of the Mutual
Recognition Arrangement for the certifications and measurements (CIPM-MRA); it is
authorized by RBLM for activities of legal metrology and by CNCAN for nuclear
activities. In this quality, LMR has the responsibility to assure the equivalence of
Romanian standards at international level by participation in comparisons and also the
traceability of the standards and measurements at national level. These objectives are
realized in three ways: delivery of radioactive standards (sources and solutions) to the
laboratories which measure activity, standardization/calibration of the measurement
equipments and organization of the inter-laboratory comparisons at national level in the
frame of the accreditation of the laboratories in conformity with the ISO/EN/IEC 17025 -
LMR has a long tradition for organization of the national comparisons, for the
measurement of the radioactive sources and solutions, finalized with remarkable results
for the laboratory and also for the participants. There were published four papers in
international and national reviews [1-4] and were issued reports distributed to the
participant laboratories and to the authorities (CNCAN, DSP).
In present, LMR is in the course of RENAR accreditation, in conformity with SR EN/ ISO/
CEI 17025 . Among the activities included in the accreditation program, the
organization of national comparisons (inter-laboratory) for the measurement of sources
and solutions activities and for the reference materials certified in LMR is included.
LMR disposes of adequate facilities for safe operation of sealed and open radioactive
sources, consisting from a radiochemistry laboratory, a balance room, two
measurements laboratories. All the personnel are qualified for nuclear activities and
posses license for work in nuclear field.
In the followings, we present a proposal for work in organization of comparison focused
manly on the choosing the type of comparison and their programs.
2. Types of inter-laboratory comparisons proposed to be organized
Our laboratory organizes four types of national (inter-laboratory)
comparisons, in the field of measuring the activity of the radioactive sources
Comparisons of low activity radioactive solutions for one radionuclide, or
from mixtures of radionuclides, from alpha, beta and gamma emitters, for
the units which measure the activity of environmental factors and for the
units from food chain.
Comparisons of high activity radioactive solutions from one radionuclide,
from gamma emitters, and for beta emitters (but the application is
conditioned of the existence, at the participants, of calibrators which were
calibrated for beta radiations), for radiopharmaceuticals units, for nuclear
medicine units from hospitals, and for the authorization and control bodies
from radiopharmaceutical field.
Comparisons of low activity radioactive sources, punctiform or extended,
from alpha and beta emitters, for the units which measure “the alpha and
beta global activity” from environment and food chain, and for the units
which calibrate and/or verify metrologically the contaminometers.
Comparisons of radioactive sources, punctiform or of volumic activity, or
certified reference materials, from gamma emitters, from one radionuclide or
from mixture of radionuclides, for units which measure the activity of the
environmental samples, or from food chain, by the gamma spectrometry
3. Mode of organization of the inter-comparisons
An intercomparison may be initialized in the following
At the solicitation of an organism which has in suborder
a net of analyzing (measurement) laboratories, like
Direction of Public Health (Radiation Hygiene) of Health
Ministry, net for Security of the Food (certification of the
radioactive content), net of Environment Radioactivity
At the solicitation of an accreditation body, which wants
to evaluate the capability of laboratories from the field,
which are in the course of accreditation
At the solicitation of an international body (IAEA)
From self initiative of the RML
4.Stages of intercomparisons
Establishing the type of inter-comparison, which define the types of sources
or solutions which will be distributed and types of participant laboratories.
Establishing the participant laboratories, if those were not specified in
organization request and sending the participation invitation, along with the
action schedule, especially with the deadline for receiving the results.
Receiving the confirmation of participating at inter-comparison and of the
details of transmitting of the samples, address, authorizations for
possession of radioactive sources, etc.
Preparation of the standard sources and solutions, which will be distributed,
in conformity with the specific procedures of the laboratory.Their verification,
before the distribution, packing, in conformity with the requirements of
transportation of the radioactive materials.
Drawing up the expedition documents, including the code of the distributed
sample, in conformity with the annexed form.
Drawing up the participation form at inter-comparison, in conformity with the
Carrying out the measurements in the participant laboratories, filling out the
forms and their expedition at IFIN-HH, Radionuclide Metrology Laboratory.
Receiving the results, their processing and issue of the project of report on
Transmitting the draft of the report to participants, only in electronic form, for
analyze and decision the final form.
Transmitting the final report, in electronic form, to participants and hard
copies to reports to the organizations which asked the inter-comparison.
Participation at exercises of inter-laboratory
comparisons is the best way of verification of the
mode of assurance of traceability at the national
level, because it implies the measurement
equipment, the standards and also the working
methods and training of the personnel.
LMR is prepared for organization of these types
of exercises, and the accreditation for these
activities will increase the quality of the actions.