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

Abstract

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 Unpublished production data and the release estimate from June 2013 yield a rough annual release estimate of 8 × 10(14) Bq of (133)Xe in 2014.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.

Monitoring and Analysis of Environmental Gamma Dose Rate around Serpong Nuclear Complex

“…An in-situ measurement using NaI(Tl) spectrometer performed in the same date by Syarbaini et al reported an increase of the 131 I and 41 Ar concentration level in the air [19]. Furthermore, release of radioxenon ( 133 Xe) was also reported in the study conducted by P. W. Eslinger et al during the operation of the facility [20]. The presence of man-made radionuclide reported by the studies and time-series response of the developed system demonstrate the effectiveness of the monitoring system to capture and quickly detect any short events that are probably related to release of radioactive materials into the atmosphere.…”