burnup characteristics analyses of graphite impurities in

Highly Sensitive Detection of Surface and Intercalated

Low-energy ion scattering (LEIS) is known for its extreme surface sensitivity, as it yields a quantitative analysis of the outermost surface as well as highly resolved in-depth information for ultrathin surface layers. Hence, it could have been generally considered to be a suitable technique for the analysis of graphene samples. However, due to the low scattering cross section for light

Fully ceramic microencapsulated fuel in prismatic high

Lu, C, Hiscox, BD, Terrani, KA Brown, NR 2018, ' Fully ceramic microencapsulated fuel in prismatic high temperature gas-cooled reactors: Analysis of reactor performance and safety characteristics ', Annals of Nuclear Energy, vol. 114, pp. 277-287.

Analysis of SHE Critical Experiments by Neutronic Design Codes

inserted together with graphite sleeves into prismatic graphite blocks. Also, burnable poi- son (BP) rods are distributed in the core, to level down the reactivity curve that declines with progress of burnup, and thus prolong fuel life. The neutronic design of

Searching for Magnetism in Hydrogenated Graphene:

Hence, in order to determine the true concentration of metallic impurities and resolve the origin of ferromagnetism, trace analyses of metallic impurities in our sample were carried out. Measurements by ED-XRF with typical detection limits in range from 1 to 10 ppm for transition metals did not show any metallic impurity such as Fe, Co, Ni or any other transition metal.

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In this study, the necessity of high grade graphite material for commercial scale HTGR is reconsidered by evaluating the burn-up characteristics and criticality of the impurity. The poison effect of the impurity, which is used to be expressed by a boron equivalent, reduces exponentially like burn-up of B, and saturate at a level of 1 % of the initial value of boron equivalent.

GUM Analysis for TIMS and SIMS Isotopic Ratios in

2007/4/1The estimation of graphite fluence through measurement of isotopic ratio changes in the impurity elements in the nuclear-grade graphite is referred to as the Graphite Isotope Ratio Method (GIRM). Combined with reactor core and fuel information, GIRM measurements can be employed to estimate cumulative materials production in graphite moderated reactors.

Impact of Fuel Type and Discharge Burnup on Source Term

burnup and fuel type on different components of the source term such as e.g. decay heat, photon emission rates and the nuclide inventory was examined. 1INTRODUCTION The spent nuclear fuel (SNF) characteristics such as decay heat and reactivity determine

BURNUP AND CRITICALITY ANALYSIS OF CARBON COATED

-217- Table (1): The fuel element characteristics Diameter of ball 6.0 cm Diameter of fuel zone 5.0 cm Density of graphite in matrix and outer shell 1.73 g/cm3 Heavy metal (uranium) loading (weight) per ball 5.0 g Enrichment of 235U (weight) 17 % Equivalent

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Burnup characteristics of this core were investigated using inexpensive graphite materials. Fig.6-3 Burnup characteristics of impurities in the fuel and reflector blocks The dashed lines show the burnup characteristics when the impurities are represented by natural boron (Nat. B); the solid lines represent the burnup characteristics when the impurities are burned directly.

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Chemical,Mineralogical,andMorphologicalPropertiesof SteelSlag

tions occurring during the removal of impurities determine the chemical composition of the basic-oxygen-furnace slag [1, 3, 5]. 2.2. Electric-Arc-Furnace (EAF) Process of Steelmaking and Slag Generation. Electric-arc furnaces (mini mills) use high-power electric

Determining the porosity and water impregnation in irradiated graphite

51 graphite), representing around 81,000 m3 of conditioned waste in cementitious packages [2]. 52 Some of the impurities contained in the nuclear graphite became neutron-activated during 53 operation, giving rise to numerous radionuclides such as 36Cl, 14C,

Joyo User's Guide

In the AGF, metallographic examination, measurements of melting point and burnup, as well as the FP release examination concerning fuel are performed. In addition, chemical and instrumental analyses of the content of minor actinide (MA) are performed in order to estimate the burnup characteristics

Modelling of Impurity Activation in the RBMK Reactor Graphite

Graphite is an important material used to moderate neu-trons in nuclear reactors. Nuclear graphite is a very pure material but still contains some impurities of various ele-ments due to graphite fabrication technology.1) These impurities (usually 0.01%)

A Study of the Oxidation Behaviour of Pile Grade A (PGA)

2015/11/17Pile grade A (PGA) graphite was used as a material for moderating and reflecting neutrons in the UK's first generation Magnox nuclear power reactors. As all but one of these reactors are now shut down there is a need to understand the residual state of the material prior to decommissioning of the cores, in particular the location and concentration of key radio-contaminants such as 14C. The

Application of the Isotope Ratio Method to a Boiling

2010/8/11Graphite reactors are particularly well-suited to such analyses since the graphite moderator is resident in the fueled region of the core for the entire period of operation. Applying this method to other reactor types is more difficult since the resident portions of the reactor available for sampling are either outside the fueled region of the core or structural components of individual fuel

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Research and Measure of Tritium andCarbon

the graphite impurities, and B-10 in the absorb balls and the control rods. The light nuclei participating the carbon-14 activation are O-17, C-13, and N-14. The reactions are listed in table 1 and 2. Table 1: Production reactions of tritium in HTR-10 type equations

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PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.

SOIL

As shown by Hayhurst and Parmar (1998), very small impurities in the graphite can cause a small part of the graphite to pyrolyse during anoxic conditions at higher temperatures. Graphitic C of lesser graphitization might therefore result in a larger loss of graphitic C during pyrolysis and a greater underestimation of the graphitic C content.

MONTE CARLO EQUILIBRIUM CYCLE ANALYSIS OF A DEEP

accommodate an extremely high burnup of ~750 GWD/tHM[4]. The moderation by graphite in an MHR produces valuable opportunities for thermal and epithermal neutrons to interact with fissionable and non-fissionable materials, respectively. In particular, the241

UNCERTAINTIES IN CALCULATIONS OF NUCLEAR moderated

graphite blocks where the control rods are inserted. CITATION-1OOOVP is a reactor core analysis code which has been improved from CITATION for the increase of memory and vectorization. The nuclear characteristics of the HTTR such as shut down

Chemical,Mineralogical,andMorphologicalPropertiesof SteelSlag

RBMK

History The RBMK was the culmination of the Soviet nuclear power program to produce a water-cooled power reactor with dual-use potential based on their graphite-moderated plutonium production military reactors. The first of these, Obninsk AM-1 (Атом Мирный, Atom Mirny, Russian for Atoms for Peace) generated 5 MW of electricity from 30 MW thermal power, and supplied Obninsk from

ON THE EVALUATION OF PEBBLE BEAD REACTOR CRITICAL

impurities in graphite, variable packing of pebbles, and moderately strong neutronic coupling are among the factors that inject uncertainty into the results obtained with lower fidelity core physics models. Some of these are addressed in this study. The

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Kawe Gidaa-naanaagadawendaamin Manoomin Launched in January 2018, Kawe Gidaa-naanaagadawendaamin Manoomin (First We Must Consider Manoomin/Psin) is a collaboration among tribes, intertribal treaty organizations, and University of Minnesota faculty, staff, and students, that prioritizes tribal views on the cultural significance and ecology of Manoomin / Psiη (Wild Rice), and the

Determination of Light Water Reactor Fuel Burnup with the

PNNL-17053 PNNL-17053 Determination of Light Water Reactor Fuel Burnup with the Isotope Ratio Method David C. Gerlach Christopher J. Gesh Mark R. Mitchell David E. Hurley Bruce D. Reid October 2007 Work performed for the Office of Defense