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Abstract: A proficiency testing feasibility study program was proposed by the National Radiation Standard Laboratory (NRSL) of Taiwan to understand the capabilities of laboratories dealing with clearance measurements, and to issue related technical criteria for radioactive waste assay. In this program, twelve blind test samples with different levels of radioactivity, radionuclides and different packing densities were prepared. Seven laboratories participated in this program and fourteen instruments were tested. Participants were required to report their raw data to NRSL, which would evaluate the effects of the background, geometry and the packing density to obtain the final results of the participants. In this study, the typical uncertainties of the participants were around 24%, and about 70% of the measured results produced En values, which were smaller than one. [Copyright &y& Elsevier]

Abstract: The Institute of Nuclear Energy Research (INER) has provided 188Re radiopharmaceuticals for hospitals in Taiwan. To enhance the accuracy of commercial radionuclide calibrators used by radiopharmacies and hospitals, and to ensure that patients receive proper doses of these radiopharmaceuticals, it is very important to standardize this nuclide. The 4πβ-γ coincidence counting method was used to standardize the mass activities of 188Re in this study. At the same time, three well type ionization chambers, Centronic IG11-N20, Centronic IG11-A20, and ISOCAL-IV, were calibrated by the standardized solutions of the nuclide. In this research, the calibration figures of ISOCAL-IV for the nuclide were consistent with the results of National Physical Laboratory (NPL, UK). The outcome implied that the results of coincidence counting did mutually agree. On the other hand, the radionuclide calibrator in the radiopharmacy was producing measurement errors of about 20% when using the manufacturers recommended calibration setting: an accurate correction factor has now been determined in this study. [Copyright &y& Elsevier]

Abstract: This study demonstrates the importance of commuting costs while determining the optimal school scale. It is found that, without commuting costs, the elementary schools in Taipei county are characterized by increasing returns to scale, and that the average public cost curve is L-shaped. However, ignoring the costs of commuting implies that the larger the school scale, the lower the cost to the public. Introducing commuting costs will raise the average cost curve, and reshape the L-shaped curve into a U-shaped curve. Once the average cost curve is U-shaped, the optimal scale of operations will lie at the lowest point. [Copyright &y& Elsevier]

Abstract: This study reports the preparation of four varieties of water extract from sweet potato leaves from Taiwan, including TNG10, TNG57, TNG66 and YSP, and evaluates their antioxidative activity. The EC50 values (scavenging DPPH radicals) of TNG10, TNG57, TNG66 and YSP were 0.27±0.01, 0.19±0.01, 0.41±0.02, and 0.31±0.02mg/ml, respectively, on a freeze-dry weight basis. The total phenolic contents of these water extracts were in the order: TNG57>TNG10>TNG66>YSP. The TNG10 and TNG57 extracts exhibited better reducing power and scavenging effects of superoxide radicals than did TNG66 and YSP. At a concentration of 1mg/ml, TNG10 and TNG57 significantly protected HaCaT cells from H2O2-induced cytotoxicity. The water extracts of YSP had more flavonoids than had those of TNG66 which may have contributed to their higher activity in many antioxidative assays. These results suggest that the water extracts of all four varieties of sweet potato leaves, and especially TNG10 and TNG57, display potent antioxidative effects. [Copyright &y& Elsevier]

Since the accident of Fukushima Daiichi nuclear power plant, the environmental radiation dose was increasingly concerned as a global issue. In Taiwan, the detection capability of the all calibration laboratories is just about 50 times the naturally occurring environmental radiation for environmental radiation protection detectors. Undoubtedly the use of environmental radiation detector shows relative low performance in accuracy and the public are very sensitive to the amount of environmental radiation. Thus, the National Radiation Standard Laboratory (NRSL) of the Institute of Nuclear Energy Research (INER) designed a multi-source of low air kerma rate calibration system to respond to the measurement and calibration needs in Taiwan. The system was verified to meet the needs of measurement and calibration through a series of evaluations and comparisons based on ISO 4037-1 criteria (ISO 4037, 1996). This environmental-level dose rate measurement and calibration system contains three radioactive sources respectively penetrating by sets of filter of three different thicknesses and then producing radiation fields of three different strengths. A total of nine standard radiation fields are provided with intensity ranges from 1746.6 μGy/h to 0.092 μGy/h, and the expanded uncertainties of the system were from 1.02% to 5.77% (k = 2). • A pressure-adjustable 10 L-nitrogen-filled ion chamber was used for air kerma determination. • A multi sources irradiator produced the irradiation field from 0.06 to 1.25 MeV gamma rays and 0.1–∼1700 μGy/h. • The tunnel-shaped shielding could reduce background interference to one tenth at the reference point. • A movable collimator and multi filters devices respectively adjust the suitable field size and air kerma rate. [ABSTRACT FROM AUTHOR]

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]

This study investigated the series of proficiency testing held by the Institute of Nuclear Energy Research (INER) from 2010 to 2017 and the benchmark of one type of dose evaluation system for personnel dosimeters in Taiwan. Based on the latest American National Standard Institute/Health Physics Society (ANSI/HPS) N13.11–2009 (R2015) performance testing standard, the personnel dose equivalent, H p (d) data of the proficiency testing programs were reanalyzed to research the dose assessment ability and the criteria update feasibility. The results showed that the tolerance level (L), absolute of bias (|B|) and standard deviation (S) for all categories of all the 8 laboratories and 4 types of dosimeter well met the latest ANSI/HPS N13.11 criteria. In addition, the measurements of the H p (d) with LiF: Mg, Ti-based TLD personnel dosimeters were also demonstrated by comparing with the MCNP6 Monte Carlo code. The dose responses were satisfactory in M100, M150 X-ray and 137Cs (including the angle tests) beams produced by INER for radiation protection level application. • In Taiwan, all 8personal dosimeter laboratories met the ANSI/HPS N13.11–2009 (R2015) criteria based on the reanalysis of pervious performance test. • The results could improve measurement quality and traceability for service laboratory using 4 different types of dosimeters. • The simulated model of Harshaw LiF:Mg, Ti-based TLD personnel dosimeter were established with MCNP6 code. • For irradiation verification, the results of equivalent dose comparison agreed within 5%–26% in the 137Cs, M100 and M150 X-ray beams. [ABSTRACT FROM AUTHOR]