Tissue free water tritium in pine needles around a nuclear power plant

The elevation of the concentration of tissue free water tritium (TFWT) in pine needles was discernible in trees growing around a nuclear power plant. The values varied from 2.6 Bq/l to 6.1 Bq/l with a mean value of 3.8 Bq/l. Analysis of pine needles collected at Fukui City as control samples was done. The values averaged 1.7 Bq/l and fell within 1.5 B/l-1.8 Bq/l which was obtained nation-wide survey of TFWT in pine needles in Japan. The present study also revealed that reactor tritium incorporated into pine needles decreased rapidly with a half time of 6 days and then tissue free water tritium has a short retention time.     

Integral fire tests with oil and cable in a nuclear power plant

Experiments with oil pool and cable fires were performed in a former Nuclear Power Plant during the last years. The fire room was a closed subcompartment equipped with ventilation ducts, fire dampers, extinguishing lines and connected by a floor to the plant containment to study fires in a real environment under conditions typical for Nuclear Power Plants. Unsolved issues such as behavior of fire damping components and filters; production of soot; fire fighters entrance to a burning room were evaluated as well as ventilation needs of involved rescue areas. The fire behavior was calculated by different types of fire codes.     

Environmental impact of radioactive silver released from nuclear power plant

Radioactive silver ^110mAg is not a fission product, but as a contaminant originating from Chernobyl, was registered in many European countries. The environmental impact of radioactive silver was specially expressed in the process of obtaining copper and noble metals from ores originating from opencast mines. Direct consequence was contaminated metal silver in the period of several years after the Chernobyl accident. It was shown that radioactive silver originating from nuclear plants, present in the environment in small concentrations due to the high concentration degrees (10⁴-10⁶) can cause high contamination in the process of the production of metal silver. Experts responsible for the functioning of nuclear power plants should have these facts in mind if they are using silver compounds in reactor core influence area.     

Environmental radiation detected at Lin Shin hospital in Taichung during the Fukushima nuclear power plant accident

This work is the first evaluation of environmental gamma exposure rates by the Nuclear Medicine Department at Lin Shin Hospital (LSH) in Taichung with Thermoluminescent dosimeter (TLD-100H) during the Fukushima Nuclear Power Plant (FNPP) accident. After the 9.0 M_W strong earthquake hit northern Japan on March 11, 2011, a TLD-100H was used to monitor environmental kerma rate at Taichung (2,500 km away from northern Japan) from Mar-08 to Apr-09, 2011 and evaluated kerma rate due to global fallout of the sever FNPP accidents. Exposure rates varied widely among positions close to the PET/CT facility. Observed kerma rates of up to 4.12 ± 0.62 mSv mo⁻¹ indicated an explicit, heavy leakage of photon through the PET/CT facility. No significant contributions were detected at Taichung, Taiwan. Hence, the health effect cause by the “extra radiation” from FNPP accidents is negligible. As this was a rare case of environmental monitoring during a nuclear power plant accident, its findings are of considerable significance.     

A long-term investigation of environmental radioactivity and public health around a nuclear power plant

Journal of Radioanalytical and Nuclear Chemistry - The aim of this work is to reveal impacts of a nuclear power plant on environmental radioactivity and public health since commission in the South...     

Assessment of the EPDM seal lifetime in nuclear power plants

An EPDM seal was qualified for use in nuclear power plants (NPPs). The primary function of the seal is to prevent leakage of unwanted fluids and gases during long-term normal operation, as well as during postulated accidents which may occur at the end of the planned service lifetime. Tested samples were compressed between two massive metal plates (the same compression as under regular service conditions) and exposed to an accelerated ageing procedure to simulate up to 10 years of operation, including accident simulation. Mechanical properties, compression set and a gas leakage test were carried out. The minimum necessary compression to keep the required tightness under all conditions during normal service and during accident conditions was found and the service lifetime was assessed for two seal thicknesses.     

Measurements of actinide nuclides in water samples from the primary circuit of a nuclear power plant

Weekly, consecutive primary coolant samples from a boiling water reactor have been analyzed for^{239, 240}Pu,²³⁸Pu+²⁴¹Am,²⁴²Cm and²⁴⁴Cm for about two years, and for²³⁸Pu,²⁴¹Pu and²⁴¹Am for one year. Concentration ranges are reported. Samples were prepared for counting either directly by evaporation or by chemical separation on BioRad AG 1×4 resin and subsequent electrolysis, and were counted in 20 cm dia Frish grid ionization chambers. Procedures are described. For most actinide nuclides, activity ratios in primary coolant were found to be different from those in worldwide fallout, thus allowing an identification of origin in the case, that actinides should be detected in the vicinity of a nuclear power station.     

Adsorption characteristics of carbon on ion exchange resin in nuclear power plant

The adsorption characteristics of carbon on a strong base anion and cation exchange mixed resin, Amberlite IRN-150 in OH⁺ and H⁻ (1∶1) used in nuclear power plant, were investigated at 6, 30 and 50 °C at a concentration of carbon up to 0.02M. The expression for the adsorption of carbon was well fitted to the Freundlich equation and the constants,k andn in the equation were deduced. Furthermore, we could explain that the adsorption capacity on the mixed resin increases with temperature.     

Improved method for the determination of manganese in nuclear power plant waters

An improved method for manganese determination in nuclear power plant waters has been developed. This method combines a selective chelation concentration method with a unique analytical separation for manganese from the interfering matrix using a weak acid cation exchange column. The detection sensitivity by conventional post-column derivatization is improved with the combination of chemical eluent suppression and subsequent post-column derivatization. The detection limit for manganese in ammonium matrix is approximately 2 pg/ml and the limit of quantitation 10 pg/ml with 100 ml sample volume.     

Purification of a primary coolant in a nuclear power plant using a magnetic filter - electrodeionization hybrid separation system

A magnetic filter — continuous electrodeionization (CEDI) hybrid separation system was investigated for the purification of the primary coolant in a nuclear power plant. A magnetic filter system with a 3000 Gauss magnetic field and a CEDI system with a cell consisting of 3 compartments were used for the removal of magnetite and nickel ions, respectively. The hybrid separation system achieved removal rates of 98% for magnetite and 99% for the nickel ions demonstrating its feasibility for the purification of primary coolant.The authors gratefully acknowledge the Basic Atomic Energy Research Institute (BAERI) program at the Korea Institute of Science and Technology Evaluation and Planning (KISTEP) for the financial support to carry out this work.     

Control of the coolant and moderator of a nuclear power plant with the aid of gas chromatography

Some complex analytical problems which are connected with the operation of nuclear power plants cooled with gas and moderated with heavy water can be solved by combination of the high separation efficiency of gas chromatography with the sensitive and selective detection of radioactive radiation. The main fields of application of these methods are the control of the coolant, of gaseous wastes, and the control of the isotopic purity of heavy water. A review of papers dealing with these problems is given describing the procedures, methods, and the results achieved.     

Krypton isotopic signature study of the primary coolant of CANDU nuclear power plant

To support interpretation of observed atmospheric krypton radioisotopes, a database of krypton radioisotope in the primary coolant of CANDU reactors has been established. This database is comprised of 40,000 records of high-quality ⁸⁹Kr, ⁸⁷Kr, ⁸⁸Kr and ^85mKr analyses. Records from the database were retrieved by a specifically designed data-mining module and subjected to further analysis. Results from the analysis were subsequently used to study isotopic ratios of observed krypton radioisotopes in the CANDU reactor primary coolant. These studies provided practical information on the characterization of CANDU reactor krypton radioisotope, which can potentially be used to discriminate between reactor effluent and fuel reprocessing for nuclear safeguard ⁸⁵Kr monitoring applications (Kalinowski et al., J Environ Radioact 73:203, 2004). The study also has some potential application to Fissile material cut-off treaty.     

Permeability of a seemingly nonporous crystal formed by a discrete metallocyclic complex

We describe the structure and permeability of a crystalline material that appears to be nonporous in a conventional sense. The material is initially formed as a solvate, and removal of the solvent molecules under relatively mild conditions proceeds via a single-crystal to single-crystal transformation, leaving the host structure intact. Although discrete unoccupied voids of 108 A3 are present in the structure, it is not possible to map open channels that represent an intuitive pathway for guest diffusion. Despite the apparent absence of pores, the material is permeable to a variety of gases including H2, O2, N2, CO, CH4, CO2, and I2. These findings show that porosity in crystalline systems cannot always be rationalized by considering the static structures and that as-yet unknown dynamic and cooperative mechanisms prevail by which porosity can be induced.     

Improvement of the radiological environmental situation due to remedial actions at a coal-fired power plant

An assessment of the radiological situation in the area of a coal-fired power plant is made in order to determine their possible impact of a waste landfill located close to the sea and to a rather populated area. The studies carried out over the past decades and repeated radioactivity measurements of slag and ash have shown that the concentration of ²³⁸U and ²³²Th decay series cannot be considered negligible. The aim of this paper was to analyse data collected in the period prior the restoration plan and compare them with the most recent data when in situ restoration measures are in progress.This revised version was published online in November 2005 with corrections to the Cover Date.     

Determination of 129I in biomonitors collected in the vicinity of a nuclear power plant by neutron activation analysis

Neutron activation analysis (NAA) was used to determine ¹²⁹I and the ¹²⁹I/¹²⁷I ratio in bovine thyroid, moss, and river sediment samples collected in the vicinity of the Temelín nuclear power plant (NPP) in south Bohemia. The NAA procedures comprised pre-irradiation separation of ¹²⁹I by combustion of the samples in the stream of oxygen at 1,000 °C and trapping the liberated iodine in a LiOH/(NH₄)₂SO₃ solution. Post-irradiation separation of ¹³⁰I produced by the reaction ¹²⁹I(n,γ)¹³⁰I was carried out by extraction of elementary iodine with chloroform followed by precipitation of PdI₂. Nondestructive, epithermal NAA was used to determine ¹²⁷I employing the ¹²⁷I(n,γ)¹²⁸I reaction. The results showed that mean values of ¹²⁹I and the ¹²⁹I/¹²⁷I ratio in the bovine thyroids varied from 22 to 61 mBq kg^?1 (dry mass) and 2.8 × 10^?9 to 5.4 × 10^?9, respectively. These values are close to the lower end of results reported from various regions non-polluted with ¹²⁹I. No significant differences were found between ¹²⁹I concentrations and the ¹²⁹I/¹²⁷I ratios in the bovine thyroids collected prior to the start and after several years of operation of the NPP. The mean value and standard deviation of ¹²⁹I in mBq kg^?1, dry mass and the ¹²⁹I/¹²⁷I ratio in moss Pleurozium schreberi were 23 ± 16 and 2.3 × 10^?9, respectively, whereas values of ¹²⁹I in the river sediments were below 8–10 mBq kg^?1 (dry mass) after several years of the NPP operation.     

Automated separation and analysis of krypton-85 from low-volume gaseous effluent of nuclear power plant

Journal of Radioanalytical and Nuclear Chemistry - Based on the requirements of the lower detection limit for the low-volume gaseous effluent, we have designed an automatic separation apparatus of...