bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposal of an alternating bending technique for evaluating low‐to‐high cycle fatigue of structural steels
Authors: Fujii Tomoyuki , Tohgo Keiichiro , Fujioka Masafumi , Muhamad Azmi Muhamad Safwan Bin , Kikushima Kodai , Shimamura Yoshinobu
Published: April 2020

This paper proposes an alternating bending technique for evaluating fatigue life in the low‐to‐high cycle fatigue regime. A method was developed for estimating the stress, elastic strain, and plastic strain ranges of a plastically deformed specimen subjected to alternating bending with consideration of stress and strain distributions. To evaluate its effectiveness, fatigue testing was conducted using a specimen made of a steel used for pressure vessels. The stress, elastic strain, and plastic strain ranges could be obtained during cyclic bending. The elastic strain amplitude life and plastic strain amplitude life curves were linear in a log–log plot in the low‐to‐high cycle fatigue regime. Hence, the fatigue life under alternating bending could be evaluated using the proposed strain‐based approach. However, these curves could not be predicted using equations with parameters obtained from tensile testing, such as the universal slope method, due to the strain gradient in the specimen.
A Geometrical Interpretation of Collinearity: A Natural Way to Justify Ridge Regression and Its Anomalies
Authors: García‐Pérez José , del Mar López‐Martín María , García‐García Catalina , Salmerón‐Gómez Román
Published: April 2020

Justifying ridge regression from a geometrical perspective is one of the main contributions of this paper. To the best of our knowledge, this question has not been treated previously. This paper shows that ridge regression is a particular case of raising procedures that provide greater flexibility by transforming the matrixXassociated with the model. Thus, raising procedures, based on a geometrical idea of the vectorial space associated with the columns of matrixX, lead naturally to ridge regression and justify the presence of the well‐known constantkon the main diagonal of matrixX′X. This paper also analyses and compares different alternatives to raising with respect to collinearity mitigation. The results are illustrated with an empirical application.
RNA demethylase ALKBH5 promotes ovarian carcinogenesis in a simulated tumour microenvironment through stimulating NF‐κB pathway
Authors: Jiang Yi , Wan Yicong , Gong Mi , Zhou Shulin , Qiu Jiangnan , Cheng Wenjun
Published: April 2020

Methylation is the main form of RNA modification. N6‐methyladenine (m6A) regulates the splicing and translation of mRNA. Alk B homologue 5 (ALKBH5) participates in the biological regulation of various cancers. However, its role in ovarian carcinogenesis has not been unveiled. In the present study, ALKBH5 showed higher expression in ovarian cancer tissue than in normal ovarian tissue, but lower expression in ovarian cancer cell lines than in normal ovarian cell lines. Interestingly, Toll‐like receptor (TLR4), a molecular functioning in tumour microenvironment (TME), demonstrated the same expression trend. To investigate the effect of abnormal TME on ovarian carcinogenesis, we established an in vitro model in which macrophages and ovarian cancer cells were co‐cultured. In the ovarian cancer cells co‐cultured with M2 macrophages, the expression of ALKBH5 and TLR4 increased. We also verified that TLR4 up‐regulated ALKBH5 expression via activating NF‐κB pathway. Depending on transcriptome sequencing, m6A‐Seq and m6A MeRIP, we found that NANOG served as a target in ALKBH5‐mediated m6A modification. NANOG expression increased after mRNA demethylation, consequently enhancing the aggressiveness of ovarian cancer cells. In conclusion, highly expressed TLR4 activated NF‐κB pathway, up‐regulated ALKBH5 expression and increased m6A level and NANOG expression, all contributing to ovarian carcinogenesis. Our study revealed the role of m6A in ovarian carcinogenesis, providing a clue for inventing new target therapy.
Cathepsin B inhibition blocks neurite outgrowth in cultured neurons by regulating lysosomal trafficking and remodeling
Authors: Jiang Muzhou , Meng Jie , Zeng Fan , Qing Hong , Hook Gregory , Hook Vivian , Wu Zhou , Ni Junjun
Published: April 2020

Lysosomes are known to mediate neurite outgrowth in neurons. However, the principal lysosomal molecule controlling that outgrowth is unclear. We studied primary mouse neurons in vitro and found that they naturally develop neurite outgrowths over time and as they did so the lysosomal cysteine protease cathepsin B (CTSB) mRNA levels dramatically increased. Surprisingly, we found that treating those neurons with CA‐074Me, which inhibits CTSB, prevented neurites. As that compound also inhibits another protease, we evaluated a N2a neuronal cell line in which the CTSB gene was deleted (CTSB knockout, KO) using CRISPR technology and induced their neurite outgrowth by treatment with retinoic acid. We found that CTSB KO N2a cells failed to produce neurite outgrowths but the wild‐type (WT) did. CA‐074Me is a cell permeable prodrug of CA‐074, which is cell impermeable and a specific CTSB inhibitor. Neurite outgrowth was and was not suppressed in WT N2a cells treated with CA‐074Me and CA‐074, respectively. Lysosome‐associated membrane glycoprotein 2‐positive lysosomes traffic to the plasma cell membrane in WT but not in CTSB KO N2a cells. Interestingly, no obvious differences between WT and CTSB KO N2a cells were found in neurite outgrowth regulatory proteins, PI3K/AKT, ERK/MAPK, cJUN, and CREB. These findings show that intracellular CTSB controls neurite outgrowth and that it does so through regulation of lysosomal trafficking and remodeling in neurons. This adds valuable information regarding the physiological function of CTSB in neural development.

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Occult hepatitis B virus infection predicts non‐alcoholic steatohepatitis in severely obese individuals from Italy
Authors: Raimondo Giovanni , Saitta Carlo , Lombardo Daniele , Giraudi Pablo J. , Rosso Natalia , Ieni Antonio , Lazzara Salvatore , Palmisano Silvia , Bonazza Deborah , Alibrandi Angela , Navarra Giuseppe , Tiribelli Claudio , Pollicino Teresa
Published: April 2020

Background & Aims

Obesity is associated with non‐alcoholic fatty liver (NAFL), which may progress towards non‐alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma (HCC). Occult hepatitis B virus infection (OBI) may contribute to hepatic damage in patients with chronic liver disease of different aetiologies (eg HCV, alcohol). However, information on the prevalence and clinical impact of OBI in obese individuals is lacking. The aims of this study were to investigate NASH prevalence and risk factors in obese people who underwent bariatric surgery.

Methods

Two‐hundred and twenty‐six subjects (160 females; mean age 42.9 years ±10.8 SD) without evidence of any further cause of liver disease consecutively underwent bariatric surgery in two Italian liver centers. During surgery, all patients underwent liver biopsy for histological evaluation and molecular studies. Liver DNA extracts were tested for PNPLA3, TM6SF2, MBOAT7, IRGM polymorphisms and for OBI. Univariate and multivariate analyses were used to identify predictors of NASH.

Results

Histology showed NASH in 115 (50.9%) and NAFL in 111 cases (49.1%). Twenty‐nine/226 (12.8%) cases had OBI, 24 (82.8%) of whom had NASH and 5 (17.2%) NAFL, whereas among the 197 OBI‐negative cases, 91 (46.2%) had NASH and 106 (53.8%) NAFL (P = .0002). Multivariate analysis showed that older age (P = .03, OR 1.034), alanine aminotransferase values (P = .005, OR 1.023), insulin resistance/diabetes (P = .02, OR 2.257), TM6SF2 polymorphism (P = .04, OR 3.168) and OBI (P = .004, OR 5.503) were independent predictors of NASH.

Conclusion

NASH is highly prevalent in obese individuals undergoing bariatric surgery. OBI is one of the strongest risk factors of NASH in these patients.
The Presidential Amnesty Programme of 2009 and Nigerian Oil Production: a disaggregate econometric analysis
Authors: Walls W.D. , During Adegboyega
Published: April 2020

We analyse the impact of the Presidential Amnesty Programme on crude oil production in Nigeria. The President of Nigeria instituted an amnesty programme in June 2009 to end the disruptive protests in the oil‐producing Niger Delta. Between 2006 and 2009, it is estimated that crude oil production losses exceeded 650,000 barrels per day, dramatically reducing government revenue. The amnesty programme provided militants a state pardon, educational training and a monthly stipend in exchange for the surrender of weapons. In this research, we use disaggregate oil‐well‐level data to estimate a difference‐in‐difference model of Nigerian crude oil production. The estimates reveal that the Presidential Amnesty Programme increased the oil output in the Niger Delta by about 40 per cent above the level that would have been achieved in the absence of the policy.
Oil prices and European household consumption expenditures
Authors: Vizek Maruška , Lee Junsoo , Payne James E.
Published: April 2020

This study examines the influence of changes in oil prices on total household consumption along with its sub‐components from 1996 to 2018, a period characterised in the literature by the declining impact of oil price shocks on macroeconomic activity. Using several dynamic panel VAR econometric approaches, we examine the role of oil prices alongside income, wealth and debt on household consumption expenditures of 30 European countries. Results from the Granger causality tests and impulse response analysis suggest an unanticipated increase in oil prices lowers household consumption. These results are robust to changes in proxies for income, wealth and oil prices, variable ordering, estimation method and the addition of household debt service. Moreover, the inclusion of a Fourier function to the baseline panel specifications to control for unobserved non‐linear structural breaks does not change our main findings. A threshold panel VAR model with median oil price changes used as a threshold indicator suggests the reaction of household consumption to oil price shocks is regime‐dependent; i.e., consumption only reacts to oil price shocks during periods when oil prices grow faster than the median rate of change. All consumption sub‐components decrease in response to increasing oil prices, but as expected, the consumption of durable goods exhibits the largest decline after an oil price shock.
Acral lentiginous melanoma: Basic facts, biological characteristics and research perspectives of an understudied disease
Authors: Basurto‐Lozada Patricia , Molina‐Aguilar Christian , Castaneda‐Garcia Carolina , Vázquez‐Cruz Martha Estefania , Garcia‐Salinas Omar Isaac , Álvarez‐Cano Alethia , Martínez‐Said Héctor , Roldán‐Marín Rodrigo , Adams David J. , Possik Patricia A. , Robles‐Espinoza Carla Daniela
Published: April 2020

Acral lentiginous melanoma is a histological subtype of cutaneous melanoma that occurs in the glabrous skin of the palms, soles and the nail unit. Although in some countries, particularly in Latin America, Africa and Asia, it represents the most frequently diagnosed subtype of the disease, it only represents a small proportion of melanoma cases in European‐descent populations, which is partially why it has not been studied to the same extent as other forms of melanoma. As a result, its unique genomic drivers remain comparatively poorly explored, as well as its causes, with current evidence supporting a UV‐independent path to tumorigenesis. In this review, we discuss current knowledge of the aetiology and diagnostic criteria of acral lentiginous melanoma, as well as its epidemiological and histopathological characteristics. We also describe what is known about the genomic landscape of this disease and review the available biological models to explore potential therapeutic targets.
Totemism of the Modern State: On Hans Kelsen’s Attempt to Unmask Legal and Political Fictions and Contain Political Theology
Authors: Górnisiewicz Arkadiusz
Published: April 2020

This paper argues that the writings of Hans Kelsen deserve more attention from those engaged in the debate on secularization and political theology. His lifelong struggle with various forms of legal‐political metaphysics is an identifiable thread in many of his writings. Kelsen’s concern with the theological‐political issues found in the theory of the state (Staatslehre) is far from being marginal. Kelsen claims that his theory aims at resolving the traditional dualism of law and state prevailing in the Staatslehre and contributes  to an “uncompromising destruction of one of the most effective ideologies of legitimacy.” Kelsen maintains that the contents of this “ideology of legitimacy” derive from both political metaphysics and the deep‐seated ancient ways of thinking on nature and society. In order to illustrate this thesis, I propose calling this phenomenon “totemism of the modern state.”
Optimization of canine CD20 chimeric antigen receptor T cell manufacturing and in vitro cytotoxic activity against B‐cell lymphoma
Authors: Sakai Osamu , Igase Masaya , Mizuno Takuya
Published: April 2020

Canine B‐cell lymphoma is one of the most common haematopoietic neoplasms in veterinary medicine, and it is considered a relevant model for human diffuse large B‐cell lymphoma. Although the standard treatment consisting of multi‐drug chemotherapy is effective in most cases, treatment is often challenging because of relapse and drug resistance. The adoptive transfer of autologous T cells genetically modified to express a CD19‐specific chimeric antigen receptor (CD19 CAR‐T cells) has been shown to be highly effective in human B‐cell malignancies. However, there is no clinically available canine CAR‐T cell therapy. We generated canine second‐generation and third‐generation CAR‐T cells by retroviral gene transduction. Optimization was performed to investigate effective viral transduction protocols and favourable culture conditions for canine CAR‐T cells. The RetroNectin‐bound virus infection method resulted in more than 70% transduction efficiency. The effect of culture conditions on the phenotype of CAR‐T cells was evaluated by the expression of surface markers. in vitro cytotoxicity assays of target cells cultured with CD20 CAR‐transduced cells demonstrated that CD20 CAR‐T cells exhibit cytotoxicity against CD20‐expressing canine B‐cell lymphoma cells and canine CD20‐transduced murine cells, whereas no effect was observed against cells that lacked canine CD20 expression. Our study established virus‐based canine CAR‐T cell generation, providing fundamental data for a better understanding of canine adoptive T‐cell therapy.
The effect of a raw vs dry diet on serum biochemical, hematologic, blood iron, B12, and folate levels in Staffordshire Bull Terriers
Authors: Anturaniemi Johanna , Zaldívar‐López Sara , Moore Robin , Kosola Mikko , Sankari Satu , Barrouin‐Melo Stella M. , Hielm‐Björkman Anna
Published: April 2020

Background

To date, very few studies have compared the effects of different types of feeding practices on canine physiology, such as feeding exclusively dry, raw, or homemade foods.

Objectives

We aimed to report the changes in hematologic, serum biochemical, plasma folate, B12, and whole blood iron levels in dogs fed two different diets.

Methods

A pilot study was developed to compare the effects of a heat‐processed high carbohydrate (HPHC) and nonprocessed high‐fat (NPHF) diet. A total of 33 client‐owned Staffordshire Bull Terriers were used; 18 had canine atopic dermatitis, seven were healthy, and eight were grouped as “borderline” dogs since they did not fulfill at least six of Favrot's criteria. The comparisons were made between the diet groups at the end visit of the diet intervention, as well as within the diet groups during the study.

Results

Significant differences between and within the diet groups were observed, although the majority of outcomes remained within the RIs. The median time of diet intervention was 140 days. Red blood cell counts, mean cell hemoglobin concentrations, and platelet counts were significantly higher, and mean cell hemoglobin, mean cell volume, alkaline phosphatase, inorganic phosphorus, and cholesterol were significantly lower in the dogs fed the NPHF diet compared with those fed the HPHC diet after the diet trial was completed. In addition, folate, B12, and iron decreased significantly in the NPHF diet group.

Conclusions

This pilot study indicated that diet had an impact on blood values, although most remained within RIs, pointing out the need for further studies.
Cementation Process for the Conditioning of Liquid Radioactive Wastes Produced During Fuel Element Reprocessing
Authors: Lippolis G. , Petagna E. , Bitonte G. , Pastore C. , Ragazzo G. , Tortorelli P.
Published: April 2020

In the past years many studies have been carried out in ITREC Plant, located in ENEA - Trisaia Research Centre, in the field of nuclear fuel reprocessing. During these activities high and low level liquid wastes were produced and stored in a special area of tanks, named Waste-1.

A specific plant, SIRTE (Integrated System for Effluents Raising and Treatment) was built, in order to condition the liquid wastes, composed of fission products, beta and gamma emitters. This plant is based on the process of cementation.

In this work, the characteristics of the plant, the phases of conditioning process and the radiological monitoring program, performed inside the plant, during the campaigns of cementation, are shown.
Proposal for Internationally Standardised Cost Item Definitions for the Decommissioning of Nuclear Installations
Authors: Teunckens Lucien , Pflugrad Kurt , Chan-Sands Candace , Lazo Eduard
Published: April 2020

Various international decommissioning projects have shown that there are substantial variations in cost estimates for individual installations. Studies to understand the reasons for these differences have been somewhat hampered by the fact that different types of cost estimation methods are used, having different data requirements. Although some uncertainty is inevitable in any costing method, an understanding of the costing methods used in particular projects is useful to avoid key uncertainties. Difficulties of understanding can be encountered and invalid conclusions drawn in making cost comparisons without regard to the context in which the various cost estimates were made.

The above-mentioned difficulties are partly due to the lack of a standardised or generally agreed-upon costing method that includes well structured and defined cost items and an established estimation method. Such a structure and method would be useful not only for project cost comparisons, but would also be a tool for a more effective cost management.

The OECD/Nuclear Energy Agency (NEA), the International Atomic Energy Agency (IAEA), and the European Commission (EC) have ongoing activities addressing various aspects of decommissioning and decommissioning costs. Based on these concurrent activities and common objectives, and on the advantages of standardised cost item definitions, the three organisations agreed to jointly prepare and to publish a standardised list of cost items and related cost definitions, for decommissioning projects. The work was carried out by Belgoprocess (Belgium) in the framework of a shared-cost contract with the European Commission (Nuclear Fission Safety Programme 1994–1998). This paper presents the results of the co-operative work.
Plasma Treatment of Radioactive Waste in Shaft Furnace
Authors: Polkanov M. A. , Savkin A. Eu. , Dmitriev S. A. , Lifanov F. A. , Popkov V. N. , Gorbunov V. A. , Spirin N. A. , Oskolkov Yu. A. , Shvetsov S. Yu. , Burov M. Yu. , Vitik N. V.
Published: April 2020

Moscow SIA RADON has developed and tested an experimental plant for treatment of radioactive waste of the mixed type including up to 40 wt. % of incombustible components with the capacity from 50 to 80 kg/h on the base of the shaft furnace with plasma heat source. Heating furnace was provided due to the arc DC plasma torch with electric capacity from 60 to 150 kW, designed at RADON. The expenses of the electric power for plasma torch were 0.5 up to 1.5 kWh/1 kg of waste depending on their composition. Pyrolytic gas with calorific value up to 4.5–5.5 MJ/kg at an output of the furnace was received, which burning provided a necessary temperature mode in the afterburner. In the shaft furnace the mode impeding radionuclides loss with off-gases has been realized. The ablation of 137Cs from the furnace did not exceed 12%, 60Co – 2.5% and trans-uranium elements – 1% due to the shaft operation mode chosen. The treatment of radioactive waste without fluxing additives has been carried out, and the slag compound with high chemical durability has been obtained.
Self-Paid Back Technologies of Clearing of Territories Contaminated With Radionuclides
Authors: Sharavarau H. , Basharin A. , Sharovarova M. , Drougatchenok M. , Bayle E. , Guiroy J. , Ardisson J.
Published: April 2020

After the explosion of the Chernobyl Nuclear Power Plant a great amount of radioactive substance was thrown out of the wrecked reactor into the atmosphere. The fall-out covered the territory of Belarus in a few big spots. The total area of the territory of Belarus contaminated with radionuclides amounts to 46.5 thousand km2. It is more than 20% of the whole territory. After the Chernobyl accident Belarus has become the zone of the ecological disaster.
Chernobyl NPP Decommissioning and “Shelter” Object Transformation: Problems of Activity Coordination
Authors: Semenova Iryna Y. , Steinberg Nikolay A.
Published: April 2020

The shutdown of the last Chernobyl NPP (ChNPP) unit essentially changes situation at the site. The plant terminates the activity as the electricity producer and starts decommissioning of the nuclear installations, located at the site. At the same time an activity connected with transformation of the “Shelter” object (the object has been erected to cover unit 4 of ChNPP destroyed by the accident at the April 26, 1986) in an ecologically safe system continues at ChNPP site. There are a large amount of scientific, engineering, economical and political issues connected to the both activities have been arisen in the past and should be resolved in the years to come.

Scope and the complexities of the tasks must be performed at the site, have no analogs in the world. The nuclear world has accumulated experience of different nuclear installations decommissioning, including NPP units, but still never taken out of service multiunit NPP in a full structure, including the unit, destroyed by the accident. Chernobyl site is unique because of 1986 accident consequences. The “Shelter” object is even more unique. The clear safety regulations for ChNPP decommissioning and the “Shelter” object transformation in an ecologically safe system are missed till now. The attempts to apply the regulations destined for “ordinary” nuclear installations in an “ordinary” surrounding environment brings up amount of issues. It is obvious that particular conditions of surrounding area, the exclusion zone, should be taken into account. The principle of “reasonable sufficiency” should be implemented to reach the safety goals of the ChNPP decommissioning and the “Shelter” object transformation without excessive financial loses and doze commitment.

Some important issues still remain unsolved: long-lived low and middle level solid radwaste (SRW) storage and storage of high-level SRW; damaged spent fuel assemblies management; polluted soil management. There is no solution on radioactive by-products management collected by the cooling lake of ChNPP in the consequences of the accident.

Large amount of radwaste and spent fuel collected at ChNPP site brings up the question about possibility and expediency of radwaste management infrastructure using which is created at ChNPP site in accordance to the National Radwaste Management Program. Obviously this question requires serious comprehensive analysis to make final decision.

Some of issues connected to peculiarities of ChNPP decommissioning and the “Shelter” object transformations in ecologically safe system (including coordination of both activities) are discussed in the presentation.
Simulation of Radionuclide Release and Subsurface Transport for LILW New Romanian Repository
Authors: Didita Liana , Ilie Petre , Pavelescu Margarit , Danchiv Alexandru , Martac George
Published: April 2020

This paper presents the main stages covered in development of the safety assessment methodology for near surface Romanian repository. It also describes the modeling approaches and assumptions used in source term modeling as well as the radionuclides transport through the unsaturated and saturated zones.

In the paper, the repository performance is assessed only by the normal evolution scenario and the beginning of the institutional control period. Transport modeling through unsaturated zone emphasizes its behaviour as a natural barrier in radionuclide migration’s way. Only a brief discussion of radionuclide transport through the saturated zone is given in this paper. The discussion is related first to the model’s characteristics, followed by the presentation of the results.
Dismantling Policy and Practice
Authors: Van Rentergem Th.
Published: April 2020

A distinction has to be made between:

• The installations still in profitable operation, such as the nuclear power plants, plants of BELGONUCLEAIRE, FBFC, “CILVA”, waste storage buildings. Hereafter, I will only speak of the most important ones, namely the nuclear power plants.

• The older installations, which have been closed or which are to be closed soon and which have never been and will never be in a profitable operation. These installations are the old Eurochemic-plant, the old waste department of the SCK•CEN, the reactors and laboratories of the SCK•CEN (BR3, BR2, …, LHMA, …), the Institute of Radio-elements in Fleurus.
Services to Nuclear Industry
Authors: Vandorpe M.
Published: April 2020

Services to the nuclear industry started at the very beginning of the nuclear industry with the construction of the first commercial units. Based on the knowledge developed in laboratories, small units were constructed and gradually extended to the large plants actually in service.

Over the past few years, reverse operations have been undertaken with the decommissioning of and the green-field operations for the oldest units.

At all stages of this work as well as during the main outage operations, external firms have been involved. Progressively these companies have built up specific knowledge including both the technical requirements identical to those of non-nuclear interventions (mechanical, electrical, engineering…) and the more nuclear-related ones (quality and safety requirements, radwaste management, radiological aspects, alara principles…).
The Decreasing Ways of Contaminated Underground Water Volume in Uranium Mining and Milling Region
Authors: Isayeva Natalya
Published: April 2020

Ukrainian uranium ore mining and milling facilities are located in the tight populated areas on the valuable agricultural lands of Ukraine. The almost 50th years’ activity of these enterprises has caused the radioactive contamination of the environment. The most dangerous facilities happened to be those ones which contaminate the entrails for a long time, namely: tailings which were discharged with the uranium ore uranium mill and former uranium in-situ leaching sites which are now decommissioned and left without relevant environmental protection measures. This paper considers two uranium facilities, which impact in a similar way on such an environmental entity as underground water: the tailings and in-situ leaching site located in Dnipropetrovsk region.
Operational Experience of TN 24 Dual Purpose Spent Fuel Storage Casks at the DOEL Nuclear Power Plants in Belgium
Authors: Baroux C. , Detrilleaux M. , Demazy G.
Published: April 2020

Spent nuclear fuel has been stored at the DOEL power station in Belgium in dual-purpose metal casks since 1995. The casks were procured from TRANSNUCLEAIRE by SYNATOM to meet the operational demands for on-site dry storage solutions for fuel arising from the four PWR reactors at DOEL. The TN 24 type of cask was chosen and a range of different cask types were developed.

The initial requirement was for dual purpose cask to contain fuel from the DOEL units 3 and 4, these having similar fuel types but different lengths, and thus two new members of the TN 24 family were developed; the TN 24 D and TN 24 XL with capacities of 28 and 24 SFA’s. These casks were licensed as B(U) fissile packagings with approval certificates granted by the French and validated by the Belgium competent authorities for the transport configurations. Both cask designs were also analyzed by TRANSNUCLEAIRE in their storage configurations to ensure that the criteria for safe interim storage could be met.

Since 1995, a total of 18 TN 24 D and TN 24 XL casks have been loaded with spent fuel assemblies with an average burn-up of 40,000 MWd/tU. SYNATOM subsequently decided to purchase further casks for DOEL 3 and 4 fuels with higher enrichments, higher burn-ups and shorter cooling times. TRANSNUCLEAIRE developed the TN 24 DH and TN 24 XLH casks within the similar envelope size and weight limits. The increase in performance was achieved by an in-depth optimization of each design in terms of radiation shielding, heat transfer and criticality safety. This paper shows how this optimization process was undertaken for the TN 24 DH and TN 24 XLH casks, 16 of which have been ordered by SYNATOM. DOEL 1 and 2 units use much shorter PWR fuel and it was decided to ship the fuel to unit 3 with an internal transfer cask because the handling limitations in the DOEL 1 and 2 pool prohibited the loading of a high capacity dual purpose transport/storage cask. The TN 24 SH cask was subsequently designed for DOEL 1 and 2 PWR fuel with a capacity of 37 assemblies and nine of there casks have been ordered by SYNATOM.

The casks are fitted with monitoring devices to detect any change in the performance of the double metal O ring closure system and none of the casks has shown any deterioration in leaktightness. This paper examines the operation experience of loading and storing more than 30 TN 24 dual purpose casks and compares the performance with design expectations.
Experience of Clean-Up Activities and Feedback to Future D&D Projects: Japan Power Demonstration Reactor Decommissioning Project
Authors: Yanagihara Satoshi , Tachibana Mitsuo , Shimada Taro , Sukegawa Takenori , Shiraishi Kunio
Published: April 2020

In the Japan Power Demonstration Reactor (JPDR) decommissioning project, the procedure for clean-up activities was specially studied for harmonization with radioactive waste treatment policy in Japan; it consisted of several components such as survey of the facility operational history, radiological characterization of building surfaces, decontamination and final survey of radioactivities. After confirming that there was no significant radioactivity in the facilities in the final step of the procedure, buildings were demolished in consideration of treatment of wastes as non-radioactive materials. The JPDR decommissioning project was completed by March 1996 with no serious problems, which showed that the procedure was rational, and that the experiences are useful for planning of future decommissioning activities. The dismantling and clean-up activities were reviewed, and the experiences are excepted to contribute to establishing standard and regulatory systems on decommissioning nuclear facilities.
Temperature Criterion Related to Clay Based Backfill Materials in the Framework of a Geological Repository of Heat Producing Radioactive Waste (HLW)
Authors: Bel Johan , Bernier Fréderic
Published: April 2020

The objective of this paper is to define a criterion for the maximum temperature allowed within clay based backfill materials, used as engineered barriers, in the framework of a geological repository of heat emitting radioactive waste. This criterion applies to all candidate geological formations in Belgium (non-indurated clay).

According to the current Belgian reference repository for vitrified High Level Waste (HLW), waste packages will be disposed in deep geological clay formations after a cooling period of about 50 years in surface storage facilities.

The heat release of this waste has a important impact on the design of the different components of the disposal system. The temperature increase and the possible effects of this increase will have to be considered on different locations (e.g. disposal galleries, backfill, lining, host rock, aquifer, and biosphere). In this paper, we will focus mainly on the temperature increase in the backfill material of the galleries.

In the past the temperature in the host rock (Boom Clay) was limited to 100°C. Consequently, higher temperatures (above 100°C) were allowed in the components between the waste and the host rock. During the preparation of the in situ demonstration project PRACLAY, a new more stringent criterion for the limitation of the temperature in the backfill has been proposed, namely the limitation of the temperature in the backfill to 100°C.

The different scientific and technical reasons for the use of this lower temperature design criterion are described in this paper. Phenomena like steam generation, mineral transformations and thermally induced, coupled effects can be reduced or avoided at lower temperatures. Another important advantage is the reduction of the corrosion rate of metal components (e.g. overpack). Finally, problems of a more technical nature (difficulty of characterization of materials, uncertainty in modeling and problems with instrumentations) can also be avoided by the use of this new criterion.

Thermal calculations point out that this new criterion can be met by respecting a cooling time, for the present repository design of vitrified HLW, of 60 years instead of 50 years.

We can conclude that the application of this lower temperature criterion provides better predictability of coupled effects and increases the performance, lifetime and robustness of the different barriers of the repository and of the disposal system as a whole.
The Recovery of Shallow Land Burial Waste
Authors: Vassallo Gary , Bielli Giuseppe , Bertelli Sergio , Marcon Gabriel , Giuffrida Daniele , Rouvière Jacques , Bertet Pierre
Published: April 2020

The JRC must recondition various radioactive wastes that were placed in a shallow land burial site during the 1960s and 70s. One such waste type at the Ispra Site are the so-called Roman pits, 7 m high columnar concrete containers in which activated metals were deposited and immobilised with cement. JRC-Ispra has fifteen such waste forms that must be recovered, characterised and reconditioned. This paper discusses the background to the Roman pits, the development of a validation procedure for demonstrating the safe recovery of a pit, and finally, the procedure’s execution.
Functional Requirements and Performance Assessment: Application to the Case of Spent Fuel Disposal in Clay
Authors: Marivoet Jan , Sillen Xavier , De Preter Peter
Published: April 2020

Geological repository systems for the disposal of radioactive waste are based on a multi-barrier design. Individual barriers contribute in different ways to the overall long-term performance of the repository system, and furthermore, the contribution of each barrier can considerably change with time. In a systematic analysis of the functional requirements for achieving long-term safety a number of basic safety functions can be defined: physical confinement, retardation / slow release, dispersion / dilution and limited accessibility.

In the case of the geological disposal of spent fuel in a clay formation a series of barriers are designed or chosen to contribute to the realisation of the basic safety functions. The physical confinement is realised by the watertight, high-integrity container, which prevents contact between groundwater and the confined radionuclides. In first instance the retardation / slow release function is realised by the slow dissolution of the waste matrix and by the limited solubility of many elements in the near field. However, the natural clay barrier provides the main contribution to this safety function. The migration of radionuclides through the Boom Clay is mainly due to molecular diffusion, which is an extremely slow process. Furthermore, many elements are strongly sorbed by the clay minerals what makes their migration even much slower. The dispersion / dilution function mainly occurs in the aquifer and the rivers draining the aquifer in the surroundings of the disposal system. Various performance indicators are used to quantify the contributions of each safety function and to explain the functioning of the repository system.
Simulation Model of Regional and Urban Development Impacts: An Approach for Transparent and Communicative LILRW Disposal Siting Process
Authors: Golobic Mojca
Published: April 2020

In most of the failed nuclear objects sitting processes the main barriers were not the technical or safety questions, but the problem of communication and reaching the public acceptance about decision. The paper presents one of the possible approaches that could contribute to the more community sensitive, transparent, communicative and finally successful siting process. The computer-supported approach for assessment of LILRW disposal impacts on regional and urban development is one of several modules loosely connected to a spatial simulation model in GIS. The results are shown as cartographic representation of impacts on different land uses and a possible future land use pattern. This model will be used for evaluation of alternative sites from regional and urban development impact aspects and for negotiating compensation schemes for local communities. One of the very important findings of this work is that the modeling outcomes depend more on value assumptions, according to which the input parameters are chosen, than on accuracy of computations. Therefore any conclusion based on the model outcomes should be verified in a wide panel of experts, interest groups and also wider public.
Managing the Environmental Impacts of Low Activity Wastes From the South African Gold Mining Industry
Authors: Wymer Denis G. , Botha Johan C.
Published: April 2020

Uranium mineralization is associated with the gold deposits in South Africa that have been mined for more than a century. Investigations of the radiological impacts on the environment reveal that the various radioactive wastes — mostly of low activity — associated with gold and by-product uranium production do not warrant the application of anything more than basic control measures. Non-radiological pollution of the water environment is a growing problem, however, aggravated by the closure and flooding of mines. Control measures to address this problem should, as a spin-off, limit the release of radionuclides, thus helping to control future radiological pollution.
Testing Permeable Reactive Barrier Media for Remediation of Uranium Plumes in Groundwater
Authors: Mallants Dirk , Moors Hugo , Wang Lian , Maes Norbert , Vandenhove Hildegarde , Diels Ludo , Bastiaens Leen , Vos Johan
Published: April 2020

In-situ treatment of contaminated groundwater by means of permeable reactive barriers (PRBs) is becoming a cost-effective remediation technique. Various reactive materials that might be used in PRBs were tested in their ability to remove uranium from groundwater. Materials tested include ferric oxyhydroxides, coarse- and fine-grained zero-valent iron, aluminium-iron oxides, and zeolites. Batch tests were used to evaluate the removal efficiency of these materials. To analyse the effect of groundwater composition on the interaction between dissolved uranium and reactive materials, two types of groundwater were used, mainly differing in carbonate content and pH. Considering an equilibration time of 48 hours and initial uranium concentrations between 2.4 and 24 mg/1, finegrained zero-valent iron proved to be most effective with a uranium removal efficiency of more than 96% for carbon-rich groundwater and 99% for carbon-poor groundwater. Intermediate efficiency was observed for coarsegrained zero-valent iron and aluminium-iron oxides. Less than 10% of the dissolved uranium was adsorbed on the iron oxyhydroxides. Zeolites did not remove any uranium from solution. Results further indicated a positive correlation between dissolved inorganic carbon content and dissolved uranium at equilibrium. Because it can be easily obtained at a fairly low price, zero-valent iron is a promising material for use in PRBs.
Investigation of the Degradation of Bituminized Products by the Stored
Authors: Yoshiyuki Ito , Toshiyuki Kondo , Yasumi Murayama , Noboru Kogawa
Published: April 2020

Bituminized products, that are soldified the low radioactive liquid wastes from Tokai Reprocessing Plant, may degrade by the progress of the stored years. Moreover, under disposal condition, it is considered that the bituminized products contact groundwater.

Therefore, it was investigated the physical properties and the gamma radionuclides of the stored products. The physical property of bituminized products did not change in about 10 years storage. And also, the leaching test was carried out, it was confirmed that the leaching of the salts was not easy to release from the bituminized product by the progress of the stored years.
Clearance/Exemption Levels for Slightly Radioactive Materials Arising From Nuclear Decommissioning and Non-Nuclear Industries
Authors: Pescatore Claudio , Teunckens Lucien , Menon Shankar
Published: April 2020

The management of the relatively large volumes of slightly radioactively contaminated material, arising from the decommissioning of nuclear facilities, represents a substantial fraction of the cost of such projects. The recycling of a relevant fraction of this material (or its reuse or disposal) without radiological restrictions, was identified by a Task Group of the OECD/NEA Co-operative Programme on Decommissioning, as a significant means of reducing such costs. The lack of internationally accepted “clearance levels” of radioactivity, at which the material could be utilised without radiological restrictions, seriously limits recycling as a waste management option.

The emergence of the NORM/TENORM issue is of great significance for the discussion of clearance regulations. TENORM arisings occur in huge quantities, two to three orders of magnitude larger than those used in European studies on recycling in the nuclear industry, and the activity levels are generally the same as in very low to low-level nuclear waste. The regulation of TENORM is in its early stages. Their occurrence in a large number of industries, as well as their activity levels and quantities, has not been generally appreciated, even by regulatory authorities, until fairly recently.

National and international bodies have suggested or are in the process of suggesting regulations for TENORM. The most important development is the publication of the European Commission Directive of May 1996 (ratified in May 2000) laying down basic safety standards for protection against ionising radiation, arising both in the nuclear and non-nuclear industries. The International Atomic Energy Agency has also started looking into this area in connection with the revision of its Safety Series 89 document. Significant to note is that both these bodies suggest release criteria into the general economy that are more relaxed for the radioactive materials from non-nuclear industries than for similarly contaminated material from nuclear industries. This issue is being taken up by several other bodies as well. This paper reviews the current debate and underlines the need for consistency in developing regulations and criteria for exemption and clearance of all radioactive materials regardless of their origin.
Political, Economic and Environmental Factors Impacting the Realization of the Plutonium Utilization Strategy in Russia
Authors: Chebeskov Alexander N. , Oussanov Vladimir I. , Iougai Serguei V. , Zavadsky Mikhail I. , Decressin Albert , Vanden Bemden Emile
Published: April 2020

The paper presents some results of system analysis of the plutonium utilization alternatives carried out by Russian specialists with an assistance of their European colleagues in the frames of ISTC#369 and #1443 Projects, financially supported by European Commission states. The multi-attribute utility (MAU) model was chose as the methodology for the analysis. For the time being the work is under continuation, but results of the first stage of the study related to conceptual features of the problem can be summed up and discussed.

The study made has shown that effective application of a quantitative model to the problem of plutonium utilization is possible provided that political and technical objectives are strictly defined. A realistic base for the scenarios under consideration is general requirement of a principal importance. The principal result of system consideration is the conclusion that transition from the practice of plutonium accumulation and storing to the strategy of plutonium utilization in nuclear reactors is justified under the real Russian conditions. In an economic sense it is justified by the reason that the expenses of reactor conversion to MOX fuel utilization are comparable with those of long-term storing of plutonium, taking into account modern, and especially future, safety requirements. On the non-proliferation criterion, conversion to MOX fuel utilization is also justified, so as in this case the main source of the proliferation risk — the plutonium store, where plutonium is being stored in the forms being the most attractive for the non-authorized usage — is eliminated. At last, conversion to utilization of stored plutonium results in the decrease of radiation risk for staff and population, as well as in the decrease of impact on the environment due to reduction of some stages of the fuel cycle.

Ranking of the plutonium utilization alternatives on a base of account economic, non-proliferation and ecological factors has led to reasonable, explicable results. These results were used in “The concept of the Russian Federation on_disposition of weapons plutonium being released in the course of nuclear disarmament”, which was approved as an official document of Ministry of Atomic Energy of Russian Federation. The main approaches of this strategy were changed significantly when comparing with the previous concept of plutonium utilization. One may expect more detailed recommendations to decision makers in course of further elaboration of scenarios and models at the following stages of the study.
Operation Experience of HALW Storage Process at the Tokai Reprocessing Plant
Authors: Nakamura Yoshinobu , Suda Shizuka , Ishiyama Koich , Watahiki Masaru , Mutoh Hideyo
Published: April 2020

Volume of nitric acid solution, which contain the most of fission products (FPs), is concentrated to 0.5–2m3 in an HALW evaporator by reprocessing a spent fuel of ltU. The HALW is stored in HALW storage tanks temporarily till it is transferred to the Tokai Vitrification Facility (TVF). During the storage, the HALW of 1–8m3/y vaporized per storage tank. A shift coefficient of radioactive nuclides from the HALW to off-gas was 4E−11. Through the operation experience, knowledge obtained about storage management of highly active liquid waste (HALW) is reported.