bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of wave, tides and fluid mud on fluvial discharge across a compound clinoform (Pliocene Orinoco Delta)
Authors: Osman Ariana , Steel Ronald J. , Ramsook Ryan , Olariu Cornel 
Published: November 2023

AbstractCompound clinoforms are well‐recognized in modern large muddy deltas and in some ancient deltas, but there is still a lack of understanding regarding their lithology variations and the process by which sand from the shoreline clinothem reaches the subaqueous clinothem foresets that are sometimes 100 km away. Net‐to‐gross, thickness and facies association evaluation show overall coarsening‐upward through a 191 m thick exposure of the late Pliocene Orinoco, Lower Morne L'Enfer Formation, with a distinct tripartite lithology distribution. The subaqueous clinothem records a lower, relatively muddy coarsening‐upward interval, 112 m thick, with net‐to‐gross increasing from zero to 60%. On the lower delta front, zero net sand units show graded beds of silt and mud with occasional spring–neap rhythmites, strongly suggesting gravity flows influenced by tidal currents. These foreset beds are overlain by structureless very fine sand, interbedded with deformed wavy to lenticular, grey fluid mud layers that rapidly accumulated near the subaqueous clinoform rollover point. The tidally dominated subaqueous platform (subaqueous delta topset), 1 to 4 m thick, shows zero net sand units with anomalously high mud content, >70%, due to the high near‐bed suspended sediment concentration of externally derived fluid mud that migrated littorally alongshore from the Amazon Delta. The interaction of freshwater river flood discharge with fluid‐mud banks gave rise to density stratification with fine sand hypopycnally dispersing as a turbulent layer above the denser fluid‐mud carpet. The shoreline clinothem (<8 m thick) has high net‐to‐gross, >85%, attributed to winnowing of sediment by waves and tides. Utilizing net‐to‐gross trends and facies changes provide useful criteria to identify compound clinoforms in the rock record. The Orinoco Delta deposits, however, are unusual, since fluid mud hinders sand deposition on the platform, allowing for easy identification of platform facies and a clear distinction between the subaqueous and shoreline clinothem in outcrop.
Aerosol Mitigation Means for Fukushima Daiichi Fuel Debris Removal
Authors: Porcheron Emmanuel , Leblois Yohan , Gelain Thomas , Journeau Christophe , Berlemont Romain , Bouland Antonin , Delalez Rémi 
Published: November 2023

Abstract
The general context of the article is to evaluate strategies that can be used to mitigate aerosols dispersion during the fuel debris or corium retrieval of Fukushima damaged reactors. IRSN is involved in several projects led by ONET Technologies along with CEA to provide relevant information to analyze the risk of aerosol resuspension induced by fuel debris retrieval. The knowledge of the aerosol source term emitted during fuel debris retrieval operations is one of the key issues for the assessment of aerosol dispersion that can lead to the release of radionuclides into the environment. Such information are also necessary to define an efficient strategy to mitigate this risk. Various mitigation means could be implemented during the decommissioning of Fukushima Daiichi damaged reactors, depending on the operations such as cutting of fuel debris or metallic structures or investigation in Primary Containment Vessel (PCV) by robots. It is also important to consider accidental scenarios such as earthquake event, to define countermeasures limiting the consequence in terms of safety and radioprotection. We propose to study various mitigation means such as the spray scrubbing technology used to collect airborne particles and therefore limit their dispersion during the cutting operations. Resuspension of deposited particles may also occur during the decommissioning operations due to various type of stress, such as aeraulic, mechanical, vibrational and also during underwater operations. To address these particle resuspension issues, another mitigation means made by coating of resins is introduced.
Transparency in Establishment of National Radioactive Waste Facilities - Criteria, Cases, Recommendations
Authors: Zeleznik Nadja , Swahn Johan , Haverkamp Jan , Hooge Niels Henrik , de Butler Malcolm , Daniska Michal , Wales Colin 
Published: November 2023

Abstract
The Civil Society (CS) experts involved in the ROUTES work package (Waste Management routes in Europe from cradle to grave) of the EURAD programme investigated how the pillars of the Aarhus convention together with a broader understanding of Transparency and Public Participation (T&PP) are transposed into Radioactive Waste Management (RWM) in the establishment of Radioactive Waste (RW) facilities, primarily geological disposal, in different national contexts. The criteria for T&PP in the development of national RW facilities are proposed and based on the RW Directive, the Aarhus Convention and the CS BEPPER report.
To obtain a broader understanding of the positions of different actors engaged in RWM, a questionnaire was submitted to ROUTES members and to the CS larger group. The focus of the questionnaire concerns transparency in the establishment of national RW facilities and included five topics: effective access to information, public participation, justice (Aarhus Convention), resources (BEPPER report) and T&PP in the development of the national programmes on RWM submitted to the European Commission pursuant to the RW Directive. Nine national cases from advanced and early stage RW programmes (Czech Republic, Denmark, Germany, Greenland, France, The Netherlands, Slovakia, Sweden and United Kingdom) are presented and discussed within the context of the pillars of good T&PP. Finally, a quality assessment is provided with lessons learned and general recommendations from the case studies, focusing on how interaction with CS could more generally and robustly contribute to the establishment of national RW facilities.
Development of Risk Assessment Code for Dismantling of Radioactive Components in Decommissioning Stage of Nuclear Reactor Facilities
Authors: Shimada Taro , Sasagawa Tsuyoshi , Miwa Kazuji , Takai Shizuka , Takeda Seiji 
Published: November 2023

Abstract
Nuclear regulation inspection should be carried out based on the risk-informed during decommissioning stage at nuclear power station. However, it is difficult because the methodology for evaluating the radiation exposure risk quantitatively during dismantling activities has not been established. Therefore, a decommissioning risk assessment code DecAssess-R has been developed based on the decommissioning safety assessment code, DecAssess, creating event trees from initiating events and evaluating the radiation risk resulting from public exposure dose for each accident sequence. In the evaluation, that movable radioactive inventory which may be easily dispersed into workspace such as radioactive dust accumulated in HEPA filters attached at a contamination control enclosure is fluctuated according to the progress of dismantling works was taken into account. Initiating events were selected based on the investigation for accidents and troubles during activities of dismantling, disassembly and replace of components around the world, and event trees from the initiating events indicating progress scenario were created. Frequencies of occurrence were set with reference to data of general industry in addition to data regarding above accidents and troubles, event progression probabilities were set with reference to failure data during the operating stage. It was also taken into account that safety functions to be maintained during decommissioning stage which the operator applied at decommissioning plan were reduced according to the progress of dismantling activities. Public exposure dose after accidental release of radioactive dusts is evaluated at exposure pathway such as cloud shine, respiration and surface deposition by atmospheric dispersion. The exposure risks during dismantling of components in reference BWR were evaluated. As a result, public exposure dose was maximum in the case of fire during dismantling of reactor internals and spread of fire to combustibles and filters including radioactivity temporally stored at the workspace. Exposure risk also showed the maximum because the occurrence possibility of this accident sequence was larger than other scenario.
Application and Improvement of Chebyshev Rational Approximation Method in Activation Calculation of Materials
Authors: Yu Xiao , Zhang Jingyu , Ni Wangmuhong , Wang Juanjuan 
Published: November 2023

Abstract
In recent years, with the development of new nuclear materials, it is necessary to accurately and efficiently analyze the activation of materials suffering from neutron irradiation to ensure the radiation protection of workers. For the activation calculations, compared with other numerical methods, the Chebyshev rational approximation method (CRAM) has comprehensive advantages regarding computational accuracy and efficiency. In this paper, the basic theory of the CRAM algorithm is first described, the partial fraction decomposition (PFD) form of CRAM is derived, and then some typical cases are selected to test and verify. The results show that the precision of order 14 CRAM is dramatically compromised by the time steps in dealing with the decay system of short-lived nuclides, which will cause the obstacle of time step selection. A new incomplete partial fractions (IPF) form of CRAM, aiming at this issue, is introduced; and the influence of different orders on time step selection is analyzed systematically. Compared with order 14 PFD, the higher-order CRAM of IPF form is more accurate in computing the decay systems of short-lived nuclides, and the selection process of time steps can be omitted.
Elemental Analysis and Radioactivity Evaluation of Aerosols Generated During Heating of Simulated Fuel Debris: The URASOL Project in the Framework of Fukushima Daiichi Fuel Debris Removal
Authors: Tsubota Youichi , Porcheron Emmanuel , Journeau Christophe , Delacroix Jules , Suteau Christophe , Bouland Antonin , Lallot Yvan , Roulet Damien , Mitsugi Takeshi 
Published: November 2023

Abstract
In order to safely remove fuel debris from the Fukushima Daiichi Nuclear Power Station (1F), it is necessary to quantitatively evaluate radioactive airborne particulate generated by the cutting of nuclear fuel debris. We fabricated Uranium-bearing simulated fuel debris (SFD) with In/Ex-Vessel compositions and evaluated the physical and chemical properties of aerosols generated by heating the SFDs. Based on these results, we estimated the isotopic composition and radioactivity of aerosols produced when 1F-Unit2 fuel debris is laser cut, which is a typical example of a heating method. Plutonium, mainly 238Pu, 239Pu 241Am, and 244Cm were found to be the alpha nuclide, and 241Pu, 137Cs-Ba, and 90Sr-Y were found to be the beta nuclide of interest.
Preliminary Thermo-Mechanical Characterization of Cement-Based Materials for LLW Immobilization
Authors: Cancemi Salvatore Angelo , Lo Frano Rosa , Paci Sandro 
Published: November 2023

Abstract
The aim of the study is to investigate the thermo-mechanical properties of cement-based materials for immobilization of low/intermediate level waste. The cementation is an important technology, nevertheless the durability of such waste form must be studied in consideration of the institutional period of storage or even under disposal conditions. Moreover, if liquid organic wastes are immobilized into cement matrix, we must face a significant technological challenge due to their complex chemical composition and relatively high activity. To investigate the durability of cement cement-based materials, an experimental campaign was carried out by performing hot wire tests on (aged/unaged) cylindrical concrete samples at temperatures ranging from 100 to 800°C.
The determination of thermal conductivity up to 800°C was obtained according to the Hot Wire Parallel Method. Additional characterization procedures included X-ray inspection, porosity measurements, compressive strength testing, and aging investigations. The activity was developed within the framework of the H2020 PREDIS project.
Further, numerical simulation by finite element method (FEM) was carried out to properly consider different conditions. The obtained results show that the cement matrix demonstrated a good level of thermal, and physical stability. The visual and X-ray inspections of the samples did not reveal any significant damages that would affect the thermal performance of the studied cement-based material.
The thermal conductivity results obtained were found to be consistent with literature values, indicating a strong correlation between the simulation results and established knowledge in the field.
Digitalization and Digital Twins in Long Term Management of Radioactive Waste
Authors: Jacques Diederik , Kolditz Olaf , Szőke István , Churakov Sergey V. , García David , Laloy Eric , Montoya Vanessa , Prasianakis Nikolaos I. , Samper Javier 
Published: November 2023

Abstract
Digitalization and Artificial Intelligence is the fastest emerging paradigms in engineering and natural science applications. As an example data-driven and physics-inspired machine learning methods have been developed and evaluated to accelerate numerical simulations; evaluating their usability for applications related to the radioactive waste management cycle is therefore of high relevance. Under the umbrella of the European Joint Programme on Radioactive Waste Management (EURAD) and on Pre-disposal Management of Radioactive Waste (PREDIS), different initiatives have been established to facilitate evaluation and implementation of digitalization technologies (and specifically digital twins mirroring their corresponding physical assets) for long-term radioactive waste management. Previous studies indicate that digitalization is an important tool, to improve processes throughout the whole waste management cycle including pre-disposal activities like waste treatment, conditioning, storage and aspects related to the operation and long-term performance of disposal systems. However, before implementation, several challenges related to different facets of digital twins and digitalization need further research. At this stage, the specific potential and role of different aspects of digital transformation for different topics of waste management is still somewhat vague. In this contribution, an overview will be given addressing selected research developments s based on activities that are ongoing in EURAD and PREDIS or in closely related activities.
Influence of Blending Phosphogypsum to Mitigate Radium Leaching and Enhance Reuse As Road Base Material
Authors: Weiksnar Kate D. , Lott Dreyton J. , Townsend Timothy G. 
Published: November 2023

Abstract
The processing of phosphate rock to produce phosphoric acid results in a calcium sulfate byproduct known as phosphogypsum (PG). This byproduct is regulated in the United States as a Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) and is managed indefinitely in monofills or gypstacks. Reuse of this material is inhibited by regulations surrounding radon release and total and leachable 226Ra concentrations, however increased interest in using PG as a road base material has developed. Many sources of PG cannot be used as a road base material alone largely due to insufficient strength and potential for 226Ra leaching. This paper investigates the influence of blending PG with common alkaline road base aggregates such as limerock and recycled concrete aggregate (RCA) to reduce 226Ra leaching from PG amended road base and provide an avenue for widespread reuse. Two sources of PG were investigated for 226Ra leaching at various pH conditions and blended with each of the two aggregate sources at up to 0,25,50, and 75% (by mass) PG to understand the behavior of 226Ra leaching. The results reveal an amphoteric leaching behavior from the PG sources alone. The blending experiment indicates an increase in leaching from PG:limerock blends initially, followed by a reduction with increasing limerock addition, and a decrease in leaching from PG:RCA blends. The amphoteric behavior of the PG paired with the leaching curves for these material blends indicates a mechanism of control of 226Ra mobility aside from change in pH, perhaps due to binding of radium by elevated concentrations of Ba, Sr, or Ca in the RCA blends. This data provides novel insight into controlling a limiting factor to PG reuse as a road base material and suggests that blending with RCA could allow for lower 226Ra mobility from PG blends and allow a larger application of PG reuse and an alternative scenario to end-of-life stacking.
Man-Portable LINAC-Based X-Ray Sources for NDT and Nuclear Security Applications
Authors: Kutsaev Sergey V. , Agustsson Ronald , Araujo-Martinez Aurora , Berry Robert , Boucher Salime , Ivanov Evgeny , Kaneta Kenichi , Kravchenko Maksim , Murokh Alex , Pronikov Alexey , Ruelas Marcos , Smirnov Alexander 
Published: November 2023

Abstract
Electron accelerators operating at energies in the MeV range and kW power levels are used for many industrial applications, including medical device sterilization, nondestructive testing cargo inspection, and radiotherapy. However, many of these applications, especially novel ones, require that size, weight, and costs of the accelerators are significantly reduced to be considered as a suitable source of radiation. Some examples of such applications include field radiography, mobile cargo inspection, radioactive source replacement and industrial irradiation. The dramatic level of miniaturization and cost-reduction is achieved thanks to the implementation of such innovative technologies as high-frequency magnetrons, novel fabrication technology, and solid-state power supplies.
In this paper we will cover the examples of man-portable accelerator-based X-ray sources for NDT and nuclear security applications, where our case studies of the accelerator system optimization for specific applications could be of interest to the broader community.
Safety Study on Korean Deep Geological Repository for High-Level Radioactive Waste: (2) Use of GoldSim for Risk Assessment
Authors: Choi Karyoung , Son Kibeom , Kim Hyungdae , Chang Kunok , Heo Gyunyoung 
Published: November 2023

Abstract
Risk, which is a quantitative representation for the degree of health risk caused by radiation exposure from disposed radioactive waste, is a main indicator for the safety of High-Level radioactive Waste (HLW) in Korean regulation, and it should be calculated by an appropriate methodology, which is not yet officially setup. Following the previous companion paper, which gives the overall description of the safety assessment, this paper shows the overall algorithm for risk assessment, actual example of a simple model by GoldSim, and the Monte Carlo simulation results for the model. This study may be an enabling step for developing deep-geological repository and carrying out the risk assessment afterwards in Korea.
Effect of High Active Raffinate Waste Composition and Loading on Early Age and Hardened Properties of Radioactive Cemented Waste Forms
Authors: Ghosh Debabrata , Ferreira Eduardo , Tri Phung Quoc , Cizer Özlem 
Published: November 2023

Abstract
This research focuses on the effects of waste loading and composition (specifically Ca(NO3)2, Ba(NO3)2 and NaNO3) on the early age properties and mechanical strength of nuclear cementitious waste forms, which are subjected to accelerated alkali-silica reaction (ASR) test. A laboratory-prepared acidic liquid waste simulating a high active raffinate (HAR) generated from the PUREX process is neutralized to a pH of 10 with a mixture of Ca(OH)2 and Ba(OH)2. The neutralized waste is then immobilized at 50, 53 and 56% by volume waste loadings (WL50, WL53 and WL56, respectively), with water/binder ratios of 0.33, 0.38 and 0.45, respectively. The immobilization matrix contains CEM I and supplementary cementitious materials such as blast furnace slag and silica fume, along with other components such as limestone fillers and lime. The mixture is cast in 40 × 40 × 160 mm3 molds and subjected to the accelerated ASR test using 1M NaOH solution at 80°C for 28 days. Afterwards, the compressive strengths are measured to check if they conform to the Waste Acceptance Criteria for homogenous cementation process (ACRIA) of ONDRAF/NIRAS in Belgium. Hydration heat and setting time are measured for the three different mixes using an isothermal calorimeter and automatic Vicat apparatus, respectively, to investigate the effect of waste loading on the early age properties. The initial heat of hydration is found to be the highest for WL50, which may be attributed to the highest percentage of cement present in the designated volume of mix. Although at a later stage, the hydration heat of WL53 and WL56 become similar to WL50, which may be due to the accelerating effect of Ca(NO3)2 in the waste sludge on the hydration kinetics.
This effect is proportional to the waste loading. Vicat data shows that the initial setting time is the lowest for WL50 followed by WL53 and WL56. One possible explanation to this is the proportional increase of Ba(NO3)2 within the designated volume with respect to waste loading. It may progressively retard the set of the mix by decomposing ettringite. However, this may also be a combined effect of increased Ba(NO3)2 and water content. A mineralogical and microstructural analysis of the samples is needed in order to examine these assumptions. Compressive strength tests after 28 days reveal average values of 42, 35 and 23 MPa for 50, 53 and 56% waste loadings respectively, which are well above the ACRIA criteria.
Securing Capacities for Safe and Sustainable Management of Contaminated Metals From Decommissioning
Authors: Larsson Arne , Schultz Bastian , Krause Gregor 
Published: November 2023

Abstract
For 35 years, Cyclife, a specialized company within the EDF Group, has provided metal treatment services to the domestic and international nuclear industry with the aim to qualify the metal for clearance and recycling for manufacturing of new products, for the manufacturing of shielding arrangements or for volume reduction.
The acceptance of free released material for conventional recycling and/or reuse within the nuclear industry has been in focus for multiple years. Now, when the treatment and recycling concepts are well established and accepted by most stakeholders, the shortage of production capacity is a new challenge to be overcome. This to secure the schedule, the logistics and overall efficiency in the decommissioning, lifetime extension and power upgrade projects.
The paper presents the current facilities within the EDF Group incl. concepts and processes for treatment and recycling as well as the ongoing extension and new-build projects.