14C High Concentration Measurements with Relevance for Decommissioning of Nuclear Reactors

Radiocarbon ◽  
2019 ◽  
Vol 61 (2) ◽  
pp. 435-444 ◽  
Author(s):  
M Enachescu ◽  
C Stan-Sion
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Isotopic Ratio ◽  
Reactor Core ◽  
High Concentration ◽  
Thermal Column ◽  
Archaeological Artifacts ◽  
Neutron Reactions

ABSTRACTDecommissioning of nuclear reactors requires determination of all remnant long-lived isotopes that were produced during their long functioning time of the respective facilities. Radiocarbon (14C) is such an isotope (T1/2 = 5730 yr), widely produced by neutron reactions in a thermal column of a nuclear reactor. Accelerator mass spectrometry (AMS) uses 14C for precise dating of up to 50,000 years old archaeological artifacts. This study presents a premier AMS measurement of high concentrated 14C samples that are strictly forbidden in laboratories dedicated to perform 14C dating. The determined 14C activities range from the natural level (isotopic ratio 14C/12C = 1.2 × 10–12) up to values of 10,000 times higher. 14C bulk and depth profile concentrations were measured in the thermal column disks of a decommissioned nuclear reactor. Results have shown that the 14C concentration in the thermal column, close the reactor core is about 75 kBq/g and decreases to 0.7 Bq/g and the end of the column. Such AMS measurements are applicable for decommissioning and waste management of nuclear reactors.

scholarly journals tudy on the determination of ¹⁰B/¹¹B isotope ratio in water samples by isotope dilution – inductively coupled plasma mass spectrometry (ID-ICPMS)

2021 ◽  
Vol 7 (3) ◽  
pp. 8-16
Author(s):  
Kim Dung Nguyen Thi ◽  
Thi Lien Nguyen
Keyword(s):  
Mass Spectrometry ◽  
Isotope Dilution ◽  
Water Samples ◽  
Inductively Coupled Plasma ◽  
Isotope Ratio ◽  
Isotopic Ratio ◽  
Primary Coolant ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

The determination of 10B/11B isotope ratio and boron concentration in various watersamples using isotope dilution technique with inductively coupled plasma mass spectrometry (ICPMS) was studied. The interferences on precision and accuracy in isotopic ratio determination by ICPMS such as memory effects, dead time, spectral overlap of 12C were investigated for the selection of optimum conditions. By the addition of certain amounts of enriched 10B into samples, the 10B/11B ratio was determined through ICP-MS signal of 10B and 11B. The detection limit for 10B and 11B was experimentally obtained as 0.26 µg/L and 0.92 µg/L, respectively. The ratios of 10B/11B in measured water samples varied in the ranged between 0.1905 and 0.2484 for different matrices. This method has been then applied for the determination of boron isotopic ratio in VVER-1000 reactor-type simulated primary coolant water and in some environmental water samples.

Comparative Studies of Turbulence Models Application in Thermal Hydraulic Analysis of Nuclear Reactor Core

2010 ◽  
Author(s):  
Heyi Zeng ◽  
Yun Guo
Keyword(s):  
Fluid Dynamics ◽  
Turbulent Flow ◽  
Secondary Flow ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Reactor Core ◽  
Turbulence Models ◽  
Flow Phenomena ◽  
Nuclear Reactor Core ◽  
Complicated Geometry

Rod bundles are essential elements of pressurized water nuclear reactors. They consist of tightly packed arrays of rods, which contain the nuclear fuel and are surrounded by flowing liquid coolant. Flow phenomena in the subchannels bounded by adjacent rods are quite complex and exhibit patterns not present in pipe flows. Development of nuclear reactors and of fuel assemblies requires fluid dynamics analysis activities. The detailed prediction of velocity and temperature distributions inside a rod bundle is one of the main objectives of the current research in reactor thermal hydraulics. Computational fluid dynamics (CFD) simulation is of great interest for the design and safety analysis of nuclear reactors since it has recently achieved considerable advancements. In the present studies, numerical simulation were performed on developed turbulent flow through core subchannels with configurations of triangle and square lattice, and impact of different turbulence models built-in software package FLUENT upon simulation results of velocity distribution and hydraulic characteristics in channels with complicated geometry were compared and analyzed. Results show that simulation result greatly depends on turbulence models. Due to the complicated geometric construction, the complicated three-dimensional turbulent flow shows highly anisotropic characteristics. Turbulence models assuming isotropic turbulent viscosity failed to predict secondary flow phenomena during turbulent flow in fuel assembly channel. By solving Reynolds stresses transport equations, more elaborate Reynolds stress model (RSM) can catch secondary flow accurately. The present studies have provided valuable references and guidelines for further investigation on convective heat transfer simulation in complicated geometry and thermalhydrulic analysis of nuclear reactor core.

scholarly journals Grape and Wine Metabolomics to Develop New Insights Using Untargeted and Targeted Approaches

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 92 ◽  
Author(s):  
Farhana Pinu
Keyword(s):  
Mass Spectrometry ◽  
Fermentation Process ◽  
Geographical Origin ◽  
Grape Juice ◽  
Wine Yeast ◽  
Gas Chromatography Mass Spectrometry ◽  
High Concentration ◽  
Analytical Instruments

Chemical analysis of grape juice and wine has been performed for over 50 years in a targeted manner to determine a limited number of compounds using Gas Chromatography, Mass-Spectrometry (GC-MS) and High Pressure Liquid Chromatography (HPLC). Therefore, it only allowed the determination of metabolites that are present in high concentration, including major sugars, amino acids and some important carboxylic acids. Thus, the roles of many significant but less concentrated metabolites during wine making process are still not known. This is where metabolomics shows its enormous potential, mainly because of its capability in analyzing over 1000 metabolites in a single run due to the recent advancements of high resolution and sensitive analytical instruments. Metabolomics has predominantly been adopted by many wine scientists as a hypothesis-generating tool in an unbiased and non-targeted way to address various issues, including characterization of geographical origin (terroir) and wine yeast metabolic traits, determination of biomarkers for aroma compounds, and the monitoring of growth developments of grape vines and grapes. The aim of this review is to explore the published literature that made use of both targeted and untargeted metabolomics to study grapes and wines and also the fermentation process. In addition, insights are also provided into many other possible avenues where metabolomics shows tremendous potential as a question-driven approach in grape and wine research.

scholarly journals Determination of Isotopic Ratio of Boron in Boric Acid Using Laser Mass Spectrometry

2005 ◽  
Vol 21 (12) ◽  
pp. 1453-1455 ◽  
Author(s):  
Periasamy MANORAVI ◽  
Mathew JOSEPH ◽  
Natrajan SIVAKUMAR ◽  
Rajagopalan BALASUBRAMANIAN
Keyword(s):  
Mass Spectrometry ◽  
Boric Acid ◽  
Isotopic Ratio ◽  
Laser Mass Spectrometry

Simultaneous Determination of Uranium and Depleted Uranium Isotopic Ratio Using Inductively Coupled Mass Spectrometry

2018 ◽  
Vol 78 (1) ◽  
pp. e59
Author(s):  
Maria A. Velez-Quinones ◽  
Hanna Xu ◽  
Nhu Vo ◽  
Joanna M. Gaitens ◽  
Melissa A. McDiarmid ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Simultaneous Determination ◽  
Isotopic Ratio ◽  
Depleted Uranium ◽  
Inductively Coupled ◽  
Inductively Coupled Mass Spectrometry

Ultra-trace determination of the 135Cs/137Cs isotopic ratio by thermal ionization mass spectrometry with application to Fukushima marine sediment samples

2019 ◽  
Vol 34 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Wenting Bu ◽  
Lei Tang ◽  
Xuemei Liu ◽  
Zhongtang Wang ◽  
Miho Fukuda ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Environmental Samples ◽  
Thermal Ionization Mass Spectrometry ◽  
Isotopic Ratio ◽  
Ionization Mass ◽  
Trace Determination ◽  
Sediment Samples ◽  
Thermal Ionization Mass ◽  
Ultra Trace

A new method was developed for determination of the 135Cs/137Cs isotopic ratio at the femtogram level in environmental samples.

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