Review of Fukushima Daiichi Nuclear Power Station debris endstate location in OECD/NEA preparatory study on analysis of fuel debris (PreADES) project

Much is still not known about the end-state of core materials in each of the units at Fukushima Daiichi Nuclear Power Station (Daiichi) that were operating on March 11, 2011. The Nuclear Energy Agency of the Organization for Economic Development has launched the Preparatory Study on Analysis of Fuel Debris (PreADES) project as a first step to reduce some of these uncertainties. As part of the PreADES Task 1, relevant information was reviewed to confirm the accuracy of graphical depictions of the debris endstates at the damaged Daiichi units, which provides a basis for suggesting future debris examinations. Two activities have been completed within the PreADES Task 1. First, relevant knowledge from severe accidents at the Three Mile Island Unit 2 and the Chernobyl Nuclear Power Plant Unit 4 was reviewed, along with results from prototypic tests and hot cell examinations, to glean insights that may inform future decommissioning activities at Daiichi. Second, the current debris endstate diagrams for the damaged reactors at Daiichi were reviewed to confirm that they incorporate relevant knowledge from plant observations and from severe accident code analyses of the BSAF (Benchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Station) 1 and 2 projects. This paper highlights Task 1 insights, which have the potential to not only inform future Decontamination and Decommissioning activities at Daiichi but also provide important perspectives for severe accident analyses and management, particularly regarding the long-term management of a damaged nuclear site following a severe accident

The analysis of enamel hypoplasia on teeth of a skeletal population from Roman Vinkovci–Cibalae, Croatia

Reconstruction of ancient people\u27s lives can be accomplished by studying their dental remains. They present a valuable source of information about the type of food people ate, illnesses they suffered from and social stratification within a community. Analysed dental remains refer to the antique period, between the 3rd and the 5th century. Romans lived in Cibalae, current Vinkovci. The purpose of this study was to evaluate the hypoplastic changes on teeth. The analysed sample consisted of the dental remains of 100 individuals with total of 2728 teeth. Enamel hypoplasia was commonly found in the observed sample, yet it appeared in a smaller number of teeth. Hypoplastic defects were more often found among the women, and were more severe - it can be assumed this is the result of a poor diet, and thus, a greater susceptibility to disease

Status of the Pit Disassembly and Conversion Facility

A planned new facility, the Pit Disassembly and Conversion Facility (PDCF) will be used to disassemble the nation`s inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. Sized to handle 35 metric tons of plutonium from pits and other sources over its 10-year operating life, the PDCF will apply the Advanced Recovery and Integrated Extraction System (ARIES) technology. ARIES process technology has been developed at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL) and an integrated system is being demonstrated LANL. Four sites were considered for locating the PDCF: Pantex Plant, Savannah River Site (SRS), Idaho National Engineering and Environmental Laboratory (INEEL), and Hanford Site. Each site offers a different opportunity for constructing the PDCF, ranging from a new building at Pantex Plant to using an existing building at Hanford Site or INEEL. The Surplus Plutonium Disposition Environmental Impact Statement was prepared by the Department of Energy (DOE) Office of Fissile Materials Disposition (OFMD) to aid in site selection. This paper describes the initial scoping activities, preconceptual and conceptual design work, and the status of the PDCF

Modeling of Surface Roughness in Plasma Jet Cutting Process of Thick Structural Steel

Today highly competitive market and demands for obtain high surface finish and machining of complex shape geometries replace conventional machining processes with non-conventional. Plasma jet cutting is one of these non-conventional processes that primary uses a thermal energy of highly ionized gas to cut specified material and blow molten metal away. Main advantages of plasma jet cutting process are high speed of cutting, cutting different types of materials, the quality of cut and moderate to low investment costs. This paper presents experimental results concerning the surface roughness variation at plasma jet cutting of structural steel S235JRG2 plate thickness of 15 mm. Using the experimental data artificial neural network (ANN) model was developed in order to predict the surface roughness in terms of two input parameters, cutting current and cutting speed. After the prediction accuracy of the developed model was validated, the model was used for analyzing influence of input parameters on process response values

Contribution of the Clinical and Histopathological Features in the Positive Diagnosis of the Juvenile Polyposis Syndrome

peer reviewedJuvenile Polyposis Syndrome (JPS) is a rare genetic disease characterized by the presence of the juvenile hamartomatous polyps. The condition is caused by germline mutation in the BMPR1A or the SMAD4 genes and it is inherited in an autosomal dominant manner. It predisposes affected persons to a high risk of malignant tumors, mainly colorectal and stomach cancers. The confi rmation of the diagnosis is based on genetic analysis. But at fi rst, family history, pedigree, clinical criteria and histopathological analysis guide to an inherited disease. We present here a Congolese patient with suggestive clinical and histopathological features which lead to the JPS

Effect of adding CaO to ZrO(2) support on nickel catalyst activity in dry reforming of methane

Nickel catalysts with a load of 5 wt% Ni, supported on pure ZrO(2) and ZrO(2) stabilized with 4, 8 and 14 mol% CaO, were prepared by the polymerization method. The samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction with hydrogen (TPR-H(2)), specific surface area (BET) and impedance spectroscopy (IS) and tested in the carbon dioxide reforming of methane. The XRD patterns showed the presence of the oxide precursor (NiO) and the tetragonal phase of CaO-ZrO(2) solid solutions. According to the TPR-H(2) analysis, the reduction of various NiO species was influenced by the support composition. The electrical properties of the support have a proportional effect on the catalytic activities. Catalytic tests were done at 800 degrees C for 6 h and the composition of the gaseous products and the catalytic conversion depended on the CaO-ZrO(2) solid solution composition and its influence on supported NiO species. A direct relation was found between the variation in the electrical conductivity of the support, the nickel species supported on it and the performance in the catalytic tests. (C) 2009 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPQFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPES