Role of the Radionuclide Metrology Laboratory in organization of the interlaboratory comparisons for the measurement of activity (Becquerel)

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Role of the Radionuclide Metrology Laboratory in
organization of the interlaboratory comparisons
for the measurement of activity (Becquerel)

• Maria Sahagia, Anamaria Cristina Razdolescu
•  Horia Hulubei  National Institute of RD for
  Physics and Nuclear Enginnering,
• IFIN-HH

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• 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
  17025-2000 requirements.
• 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 5. 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.

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• 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
  and solutions.
• 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 method.

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• 3. Mode of organization of the inter-comparisons
• An intercomparison may be initialized in the
  following situations
• 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 Survey.
• 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

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• 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 annexed
  model.
• 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
  inter-comparison.
• 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.

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• Conclusions
• 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.