Source term estimates of radioxenon released from the BaTek medical isotope production facility using external measured air concentrations.

BATAN Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies (99m)Tc for use in medical procedures. Atmospheric releases of (133)Xe in the production process at BaTek are known to influence the measurements taken at the closest stations of the radionuclide network of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The major xenon isotopes released from BaTek are also produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide if a specific measurement result could have originated from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84 × 10(13) Bq of (133)Xe. Concentrations of (133)Xe in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88 × 10(13) Bq. The same optimization process yielded a release estimate of 1.70 × 10(13) Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10% of each other. Unpublished production data and the release estimate from June 2013 yield a rough annual release estimate of 8 × 10(14) Bq of (133)Xe in 2014. These multiple lines of evidence cross-validate the stack release estimates and the release estimates based on atmospheric samplers.

National comparison of activity measurements of ¹³¹I, 6°Co, and ¹³³Ba in Indonesia.

National comparisons of radioactivity measurements of (131)I and (60)Co (in 2010) and of (133)Ba (in 2011) were carried out within the framework of the National Radiation Metrology Laboratory Program of Indonesia, coordinated by PTKMR-BATAN. Eleven laboratories took part in the comparison, and all measurements were made using gamma spectrometry, on point sources with an activity between 2000Bq and 6000Bq. Several laboratories reported values which were more than 10% different from the reference value for (131)I and (133)Ba. Possible reasons for these differences are discussed. This program will be continued with other radionuclides to maintain and control quality assurance for the local laboratories.

Direct measurement of 6°Co and ¹²5I activity by the sum-peak method in PTKMR-BATAN.

The sum-peak method was successfully applied to the determination of the activity of (60)Co and (125)I sources measured by HPGe and well-type NaI(Tl) detectors in PTKMR-BATAN. The result of the (60)Co activity agrees with the activity value measured by using a calibrated ionization chamber within a range of about 0.35-0.5% and the activity result of (125)I agrees with the activity value measured using the photon-photon coincidence method within a range of 0.05-0.26%.

Performance evaluation of commercial radionuclide calibrators in Indonesian hospitals.

Dose calibrator is one of the supporting equipments in the field of nuclear medicine. At the hospitals, dose calibrator is used for activity measurement of radiopharmaceutical before it is administered to patients. Comparison of activity measurements of (131)I and (99m)Tc with dose calibrators was organized in Indonesia during 2007-2010 with the the aim of obtaining information dose calibrator performance in the hospitals. Seven Indonesian hospitals participated in this comparison. The measurement results were evaluated using the E(n) criteria. The result presented in this paper facilitated the evaluation of dose calibrator performance at several hospitals.

Standardization of 125I and 109Cd by the photon-photon coincidence method in PTKMR-BATAN.

A photon-photon coincidence system was constructed for the standardization of (125)I and (109)Cd in PTKMR-BATAN, Indonesia. Two NaI(Tl) detectors of 76 mm diameter × 6mm thickness with 0.5mm aluminum window were used, which were positioned approximately symmetrically to the source holder. The electronic chain was almost the same as for a 4πß-γ system. The CANBERRA Multiport II multi channel analyzer was used for energy calibration and a Philips type PM3092 oscilloscope for visualization of the pulses. A polyethylene plastic was used as the source substrate for the (125)I and (109)Cd samples. The activity of a (125)I solution was measured by the photon-photon coincidence and the efficiency extrapolation method (Schrader and Walz, 1987), whereas the activity of a (109)Cd solution was determined by a tracer method using (125)I (Schrader, 2006). The result of the (125)I activity showed good agreement with the result of measurements using a calibrated ionization chamber, and the result of (109)Cd also showed good agreement with the measurements result using a LEGe detector.

Radioactivity measurement of 18F in 16 ml vials for calibration of radionuclide calibrators.

Fluorine-18 is obtained through the reaction (18)O(p, n)(18)F using a cyclotron that is situated in a hospital in Jakarta. Standardization of the (18)F solution is performed by gamma spectrometry using calibration sources of (152)Eu, (60)Co and (137)Cs that have traceability to the International System of units (SI). The activities in the 16 ml vials that were used for calibrating the radionuclide calibrators were between 1 and 2 GBq, with expanded uncertainties of 3.8%. The expanded uncertainty, at a coverage factor of k=2, on the derived calibration factor for the radionuclide calibrator was 6.6%.

Laboratories new to the ICRM.

The Scientific Committee of the ICRM decided, for the 2011 Conference, to present laboratories that are at a key developmental stage in establishing, expanding or applying radionuclide metrology capabilities. The expansion of radionuclide metrology capabilities is crucial to meet evolving and emerging needs in health care, environmental monitoring, and nuclear energy. Five laboratories (from Greece, Lithuania, Indonesia, Norway and Turkey) agreed to participate. Each laboratory is briefly introduced, and examples of their capabilities and standardization activities are discussed.