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Abstract: 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 90Sr 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 90Sr, CF(90Sr), in fish bone was no statistic difference between non-predatory and predatory fish. Besides, the accumulation of 90Sr 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 90Sr activity concentration and the fish weight. Regarding the activity concentrations of 90Sr in fish bone, all the fish were observed positively correlated with the measured [Sr]bone. [Copyright &y& Elsevier]

Abstract: The electronic radon monitors are noted for their convenience and acceptable accuracy. Even so, it is necessary to reassure their data quality regularly. We utilized a performance comparison system for this purpose. The instruments in our laboratories (Alphaguard, RAD7, RTM-2100 and Safety Siren) were tested via the comparison experiments. We conclude that by utilizing this system with the concept of calibration factor, it can be helpful to decide whether to send the monitors back to the original manufacturers for adjustment. [Copyright &y& Elsevier]

Abstract: In this study, to improve the problem of waiting for the growth of 90Y for Cerenkov counting and save the time of 90Sr analysis, an organic cocktail sample was counted by a liquid scintillation counting system immediately after the purification of 90Sr without waiting for the growth of 90Y. The chemical separation and the measurement procedures for 90Sr radioactivity analysis can be completed in 24h. In order to verify the performance of the improved method, the activity of 90Sr in six environmental reference samples was determined after radiochemical purification with a crown-ether resin column, and subsequent measurement by both the Cerenkov and the organic cocktail liquid scintillation counting methods. The results revealed that the organic cocktail liquid scintillation counting was quicker and had higher efficiency and lower minimum detectable activity (MDA) than the Cerenkov counting. [Copyright &y& Elsevier]

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]

A procedure has been developed to provide sequential analysis of 238Pu, 230Th, 241Am, 238U, and 90Sr in environmental and bioassay samples. Tracers and/or carriers (242Pu, 243Am, 232U, and stable strontium) are added into the sample as chemical yield monitors, and then, plutonium, thorium, strontium, americium, and uranium are sequentially separated and purified by Dowex ion-exchange resin, EiChroM Sr-resin, EiChroM TRU-resin, and Chelate-100 resin, respectively. The radioactivities of 90Sr and the actinides are measured using the liquid scintillation counter and alpha-particle spectrometer, respectively. Acidified water, glass-fiber air filter, soil, synthetic urine and synthetic feces samples of US National Institute of Standard and Technology Radiochemical Intercomparison Program(NRIP) were analyzed to verify this method. All the analytical results of 238Pu, 230Th, 90Sr, 241Am and 238U meet the traceability limit per ANSI N42.22, and when appropriate, evaluation of radiobioassay measurement bias and precision per ANSI N13.30. [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]

Abstract: Institute of Nuclear Energy Research (INER) has designed an air-cooling distillation device and got a US patent. The decontamination factor 60Co and 137Cs is above 23,000. Tritium loss rate is one of testing items in ASTM D4107 Standard Test Method for Tritium in Drinking Water. In this study, the 3 levels (high, middle and low level) of tritium concentration of testing samples for the loss rate test were prepared similar to the concentrations reported in ASTM D4107. The loss rate of the high level is −2.37%, the middle is −2.31% and the low level is −2.47%. These results show that the air-cooling distillation device has good performance in the environmental water tritium analysis work. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: The drum counting system was calibrated in this study. For 137Cs, the counting efficiencies were around 14–1% when the density of the waste of the drum was changed from 0.15 to 2.3gcm−3. The effects of the background, hot spot, system linearity, sample density and weighing were also evaluated in this work. The combined standard uncertainty of the drum counting system for the 137Cs in the density of 1g cm−3 was around 12%. To verify the counting system, the drums containing radioactive solution were prepared by the NMI as the blind samples. A discrepancy below 15% was shown between the counting results and the reference values of the NMI. [Copyright &y& Elsevier]

Abstract: Performance tests of a movable gamma-ray waste drum scanning system were carried out in this study. The scanner consists of a single HPGe detector on a movable cart with a 90° collimation angle to the observed item. The detection efficiency for 137Cs was determined using the ISOTOPIC software. The activities of 35 low-level radioactive waste drums were measured using this system and compared with the results of two other measurement systems. This movable scanning system gave the same result as the other two systems with a relative spread (one standard deviation) of about 7.2%. [Copyright &y& Elsevier]

Abstract: Radio pollutant removal is one of several priority restoration strategies for the environment. This study assessed the effect of low molecular weight organic acid on the lability and mechanisms for release of 137Cs from contaminated soils. The amount of 137Cs radioactivity released from contaminated soils reacting with 0.02M low molecular weight organic acids (LMWOAs) specifically acetic, succinic, oxalic, tartaric, and citric acid over 48h were 265, 370, 760, 850, and 1002Bqkg−1, respectively. The kinetic results indicate that 137Cs exhibits a two-step parabolic diffusion equation and a good linear relationship, indicating that the parabolic diffusion equation describes the data quite well, as shown by low p and high r 2 values. The fast stage, which was found to occur within a short period of time (0.083–3h), corresponds to the interaction of LMWOAs with the surface of clay minerals; meanwhile, during the slow stage, which occurs over a much longer time period (3–24h), desorption primarily is attributed to inter-particle or intra-particle diffusion. After a fifth renewal of the LMWOAs, the total levels of 137Cs radioactivity released by acetic, succinic, oxalic, tartaric, and citric acid were equivalent to 390, 520, 3949, 2061, and 4422Bqkg−1 soil, respectively. H+ can protonate the hydroxyl groups and oxygen atoms at the broken edges or surfaces of the minerals, thereby weakening Fe–O and Al–O bonds. After protonation of H+, organic ligands can attack the OH and OH2 groups in the minerals easily, to form complexes with surface structure cations, such as Al and Fe. The amounts of 137Cs released from contaminated soil treated with LMWOAs were substantially increased, indicating that the LMWOAs excreted by the roots of plants play a critical role in 137Cs release. [Copyright &y& Elsevier]

Abstract: The dynamics of Cs and Sr sorption by soils, especially in the subtropics and tropics, as influenced by soil components are not fully understood. The rates and capacities of Cs and Sr sorption by selected subtropical and tropical soils in Taiwan were investigated to facilitate our understanding of the transformation and dynamics of Cs and Sr in soils developed under highly weathering intensity. The Langmuir isotherms and kinetic rates of Cs and Sr sorption on the Ap1 and Bt1 horizons of the Long-Tan (Lt) and the A and Bt1 horizons of the Kuan-Shan (Kt), Mao-Lin (Tml) and Chi-Lo (Cl) soils were selected for this study. Air-dried soil (<2mm) samples were reacted with of 7.5×10−5 to 1.88×10−3 M of CsCl (pH 4.0) or 1.14×10−4 to 2.85×10−3 M of SrCl2 (pH 4.0) solutions at 25°C. The sorption maximum capacity (q m) of Cs by the Ap1 and Bt1 horizons of the Lt soil (62.24 and 70.70mmolCskg−1 soil) were significantly (p <0.05) higher than those by the A and Bt1 horizons of the Kt and Cl soils (26.46 and 27.49mmolCskg−1 soil in Kt soil and 34.83 and 29.96mmolCskg−1 soil in Cl soil, respectively), however, the sorption maximum capacity values of the Lt and Tml soils did not show significant differences. The amounts of pyrophosphate extractable Fe (Fep) were correlated significantly with the Cs and Sr sorption capacities (for Cs sorption, r 2 =0.97, p <1.0×10−4; for Sr sorption, r 2 =0.82, p <2.0×10−3). The partition coefficient of radiocesium sorbed on soil showed the following order: Cl soil≫Kt soil>Tml soil>Lt soil. It was due to clay minerals. The second-order kinetic model was applied to the Cs and Sr sorption data. The rate constant of Cs or Sr sorption on the four soils was substantiality increased with increasing temperature. This is attributable to the availability of more energy for bond breaking and bond formation brought about by the higher temperatures. The rate constant of Cs sorption at 308K was 1.39–2.09 times higher than that at 278K in the four soils. The activation energy of Cs and Sr sorbed by the four soils ranged from 7.2 to 16.7kJmol−1 and from 15.2 to 22.4kJmol−1, respectively. Therefore, the limiting step of the Cs+ or Sr2+ sorption on the soils was diffusion-controlled processes. The reactive components, which are significantly correlated with the Langmuir sorption maxima of Cs and Sr by these soils, substantially influenced their kinetic rates of Cs and Sr sorption. The data indicate that among components of the subtropical and tropical soils studied, short-range ordered sesquioxides especially Al- and Fe-oxides complexed with organics play important roles in influencing their capacity and dynamics of Cs and Sr sorption. [Copyright &y& Elsevier]

Abstract: 137Cs is one of the major artificial radionuclides found in environments; but the mechanisms behind fertilizer-induced 137Cs desorption from soil remain unknown. This study aimed to investigate the kinetics and mechanisms underlying the various cations and anions that cause Cs release from soil under acidic conditions. NH4H2PO4 (1M), 0.5M (NH4)2SO4, 1M NH4Cl, 1M KCl or 1M NaCl solutions were added to 137Cs-contaminated soil. The power function model well described the short term 137Cs desorption with the solutions. The rate coefficients for 137Cs release from soil in NH4H2PO4, (NH4)2SO4, NH4Cl, and KCl solutions were 7.7, 7.3, 6.8, and 6.1 times higher than the rate observed in a NaCl solution, respectively. The NH4H2PO4 and (NH4)2SO4 solutions induced significantly greater 137Cs release from the contaminated soil than the NH4Cl, KCl and NaCl solutions. After four times repeated extractions with the fertilizer solutions, the total amount of 137Cs extracted by (NH4)2SO4 and NH4Cl solutions reached equilibrium, while that extracted using an NH4H2PO4 solution continued to increase. The combined effect of phosphate and protons was the major mechanism behind 137Cs release from contaminated soils, when an NH4H2PO4 solution was used. [Copyright &y& Elsevier]

Abstract: 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 &y& Elsevier]