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Abstract: To guarantee the measurement quality for clearance level in solid waste material, the Institute of Nuclear Energy Research (INER) established the criteria for proficiency testing of clearance level measurement. INER and the Taiwan Accreditation Foundation (TAF) organized the Technique Committee Meeting twice to discuss these criteria in 2011. The participating laboratories must completely conform to the ISO/IEC 17025, and they also must meet the requirements of the criteria. According to the criteria, the participating laboratories analyzed the minimum detectable amount (MDA) and that should be less than 20% of the clearance level (AMDA) given in the Atomic Energy Council's (AEC) “Regulations on Clearance Level for Radioactive Waste Management”. The testing results should conform to the deviation and traceability requirements. [Copyright &y& Elsevier]

Abstract: To realise radioactive environmental reference materials in Taiwan, seven environmental materials of soil, water, vegetation, meat, airborne particles (filter paper), milk and mushroom samples that are frequently encountered were used to establish the preparation of the reference materials. These seven environmental materials were collected, checked for freedom from radioactivity and prepared according to their properties. The preparation was carried out by using activity about 10–100 times that of the minimum detectable activity (MDA) in routine measurements in the radioactive standard used to spike the inactive material and this standard is traceable to national ionising radioactivity standards (TAF, 2004). To demonstrate sample traceability to the added standard, each sample was carefully measured and its uncertainty evaluated. Based on the recommendations of ISO Guide 35 for evaluation of reference materials and with the above assessment and verification procedures, the uncertainties (k=1) of the spike activity used in making reference materials were: 60Co≤4.6%, 134Cs≤4.7%, 137Cs≤5.0%, total β≤0.6% and 3H≤1.3%. [Copyright &y& Elsevier]

Abstract: A procedure using liquid scintillation counting for the monitoring of gross alpha and beta activities in environmental water was implemented to improve the conventional procedure using GFPC adopted in Taiwan. The new procedure was acquired through calibration and validation, and then was applied to the monitoring of surface water in Taiwan. This procedure can improve 2–4 times of detection efficiencies and takes only 70–80% of analysis time with reliable accuracy. With these features, the newly developed procedure is favorable during emergency situations. [Copyright &y& Elsevier]

Abstract: Seven kinds of spiked low-level activity samples were used for the 2004–2007 proficiency testing program in Taiwan. There were 711 reported data of Gross-β, 3H, 60Co, 90Sr and 137Cs were collected, and the bias, precision and traceability were evaluated. All the results were “Acceptable” for bias and precision, but 102 data were “Not Acceptable” for traceability. It reveals that the laboratories had good proficiency and well QA/QC management in routine practices, but the measurement uncertainty may be underestimated or overestimated. [Copyright &y& Elsevier]

Abstract: Oysters around the coast of Taiwan were collected, dried, spiked with a 209Po tracer for yield, digested with concentrated HNO3 and H2O2, and finally dissolved in 0.5N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of 210Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of 210Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that 210Po average activity concentrations ranged from 23.4±0.4 to 126±94Bqkg−1 of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of 210Po in comparison with oysters from other regions of Taiwan. The value of 210Po weighted average activity concentrations for all oyster samples studied is 25.9Bqkg−1. The annual effective dose of Taiwanese due to the ingestion of 210Po in oysters was estimated to be 4.1×10−2 mSvy−1. [Copyright &y& Elsevier]

Three kinds of fish from a natural fishpond in the north of Taiwan were collected and analyzed in this study. The three species were non-predatory Ctenopharyn odon idellus, predatory Aristichthys nobilis and predatory Mylopharyngodon piceus. The activity concentrations of (90)Sr in bone and edible flesh of fish, as well as in water and soil of fishpond were measured by using the radiochemical analysis. Additionally, the concentration of stable calcium in fish bone, [Ca]bone, and that of stable strontium in fish bone, [Sr]bone, were measured by ICP-AES. From the results, the concentration factors of (90)Sr, CF((90)Sr), in fish bone was no statistic difference between non-predatory and predatory fish. Besides, the accumulation of (90)Sr in the non-predatory fish remarkably decreased with increasing the fish weight. As for the predatory fish, they both showed no statistically significant correlations between the (90)Sr activity concentration and the fish weight. Regarding the activity concentrations of (90)Sr in fish bone, all the fish were observed positively correlated with the measured [Sr]bone., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The 3-11 Earthquake occurred in Japan last year had greatly damaged the lives and properties and also caused the core meltdown accident in the Fukushima nuclear power plant followed by the leakage of radioactive materials into biosphere. In order to protect against the detriment of radiation from foods which were imported from Japan, the Institute of Nuclear Energy Research (INER) in Taiwan started to conduct radioactivity inspection of food products from Japan after the accident. A total of about 20,000 samples had been tested from March 24 2011 to March 31 2012., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Oysters around the coast of Taiwan were collected, dried, spiked with a (209)Po tracer for yield, digested with concentrated HNO(3) and H(2)O(2), and finally dissolved in 0.5 N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of (210)Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of (210)Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that (210)Po average activity concentrations ranged from 23.4 ± 0.4 to 126 ± 94 Bq kg(-1) of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of (210)Po in comparison with oysters from other regions of Taiwan. The value of (210)Po weighted average activity concentrations for all oyster samples studied is 25.9 Bq kg(-1). The annual effective dose of Taiwanese due to the ingestion of (210)Po in oysters was estimated to be 4.1 × 10(-2) mSv y(-1)., (Copyright © 2013. Published by Elsevier Ltd.)

The nuclear facilities at Institute of Nuclear Energy Research (INER) had been successively decommissioned and decontaminated over the recent years. Since dismantling was a complex task, to achieve the main goal was minimization of radioactive waste production and required the set-up of procedures, criteria of free release, strict follow-up and traceability at all steps. This study gave an overview of the efforts on non-destructive assay (NDA) of relatively large volumes of waste and the sampling of contaminated waste with radiochemical analysis was utilized to determine the radionuclide vectors. The experiences of free release planning and measurement of a very low level radioactivity with high throughput for scrapped metal at the INER and the technical achievements in this research could offer a reference of decision-making by the competent authority.