Autophagy of the Nucleus in Health and Disease

Nucleophagy is an organelle-selective subtype of autophagy that targets nuclear material for degradation. The macroautophagic delivery of micronuclei to the vacuole, together with the nucleus-vacuole junction-dependent microautophagic degradation of nuclear material, were first observed in yeast. Nuclear pore complexes and ribosomal DNA are typically excluded during conventional macronucleophagy and micronucleophagy, indicating that degradation of nuclear cargo is tightly regulated. In mammals, similarly to other autophagy subtypes, nucleophagy is crucial for cellular differentiation and development, in addition to enabling cells to respond to various nuclear insults and cell cycle perturbations. A common denominator of all nucleophagic processes characterized in diverse organisms is the dependence on the core autophagic machinery. Here, we survey recent studies investigating the autophagic processing of nuclear components. We discuss nucleophagic events in the context of pathology, such as neurodegeneration, cancer, DNA damage, and ageing.

The Efficacy of the Global Nuclear Security Legal Regime and States’ Implementation Capacity in Light of the Forthcoming Development of Advanced Nuclear Reactor Technologies

The forthcoming arrival of small modular reactors and other advanced nuclear reactor technologies can be an immensely beneficial development in the world’s collective pursuit of energy security and meeting climate change objectives. The key question is whether or not these new reactor technologies significantly alter the fundamental premises underlying the existing nuclear security legal regime. The Convention on the Physical Protection of Nuclear Material and its Amendment (A/CPPNM) are the only legally binding international instruments governing the physical protection of nuclear materials and nuclear facilities. Together the A/CPPNM and the international guidance on nuclear security comprise the current legal framework for nuclear security. This chapter examines whether the A/CPPNM adequately covers advanced reactor technologies; and whether the States that are interested in acquiring these new reactor technologies have the capacity to effectively implement the associated legal requirements, regulatory standards, and international guidance that comes along with such technologies. The analysis touches upon the role of the International Atomic Energy Agency (IAEA), the IAEA Nuclear Security Guidance, and issues of cybersecurity.

IAEA Safeguards: Correctness and Completeness of States’ Safeguards Declarations

In the light of the occasional challenges in recent years to the legal authority of the International Atomic Energy Agency (IAEA) to verify the correctness and completeness of States’ declarations under comprehensive safeguards agreements, the chapter assesses the law and practice on this issue since the early 1990s. In particular, the chapter focuses right and obligation of the IAEA to verify the correctness and completeness of States’ declarations—one of the most fundamental principles in the implementation of comprehensive safeguards agreements. The chapter provides a detailed textual and historical analysis indicating that, in fulfilling that obligation, the IAEA is not limited to access to information about nuclear material which has been declared by the Agency, or to locations where such material has been declared by the Agency. A contrary interpretation would cause the IAEA to revert to a pre-1991 approach to verification that focused primarily on declared nuclear material, which resulted in the IAEA’s failure to detect Iraq’s undeclared nuclear programme.

Assessment of Seismogeodynamic Activity of Mining Areas on the Basis of 3D Geoinformation Modeling

The article deals with the creation of an information and analytical platform for assessing external causes of technogenic (man-made) accidents and for improving methods of their predication and prevention on the territories of long-term geological, mining, and engineering activities on the Southeastern (SE) Transbaikal region example — one of the key areas for mining and extraction of the strategic raw minerals in Russia. 3D modeling of active geological structures and hazardous seismogeodynamic processes on GIS-based technologies is a key instrument for forecasting dangerous natural and technogenic events and risk reduction of their occurrence. A matter of minimizing consequences of natural and technogenic disasters for such facilities of increased technological and environmental hazards as minefields, radiochemical facilities, sites for spent nuclear material disposal, dams, gas and oil pipelines, etc. has become essential. It is necessary to assess modern geodynamic territory’s activity on a unified geoinformation platform applying the newest integrated geological-geophysical researches’ methods for these objects, to select seismically active fault-fracture zones, to determine the rate and direction of surface displacement, to establish patterns of subsoil stressed-strained state natural component influence on behavior of local technogenic processes. Taking into account the specificities of geotectonic structure of mining territories, the structure of monitoring seismogeodynamic processes network on multifunctional geodynamic test sites should be developed. Observations made on test sites form the information basis for forecasting of lithosphere condition, taking decisions on rational subsurface management and providing ecological safety of the territory.

Study on specific heat capacity and thermal conductivity of uranium nitride

In this study, we have proposed an analytical method for calculating the specific heat capacity of uranium nitride nuclear material. The specific heat capacity results have obtained by the use of the Debye-Einstein approximation. The thermal conductivity of nuclear material has been obtained by using the experimental data of thermal diffusivity and the calculation results of specific heat capacity. This method shows that our results are satisfactory for the wide range temperature variations. The proposed approach can be easily applied to determine the thermodynamic properties of the other nuclear materials.

Critical comparison of INAA and ICP-MS applied in the characterization of purity of TRISO fuel and substrates to its production

The application of inductively coupled plasma mass spectrometry (ICP-MS), both in solution and laser ablation (LA) mode, and instrumental neutron activation analysis (INAA) in the nuclear material analysis are presented in this paper. The possibility of each technique for the chemical characterization of substances used during TRISO fuel production and its advantages and limitations are discussed based on the obtained results of the analysis of real materials used in TRISO fuel production in the Institute of Nuclear Chemistry and Technology. The paper also reports the application of INAA and LA-ICP-MS to the verification of the purity of the protective layers of pyrolytic carbon (PyC) and silicon carbide.

International safeguards for the final disposal of spent nuclear fuel – why, what and how

The objectives of international safeguards are the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons (or for other purposes), and deterrence of such diversion by the risk of early detection for states with comprehensive safeguards agreements with the International Atomic Energy Agency (IAEA). Following these objectives, several studies have focused on the developments of concepts and methods for safeguarding final disposal facilities as well as on identifying the most feasible technologies that could potentially be deployed for verifying final disposal programmes (IAEA, 1998, 2010, 2018). These activities were coordinated through Member State Safeguards Support Programmes, including the joint tasks on the development of “Safeguards for Geological Repositories” (SAGOR, 1994–2004) and on the “Application of Safeguards to Geological Repositories” (ASTOR, 2005–2017). SAGOR performed a diversion path analysis for spent fuel disposal facilities, determined safeguards technical objectives and identified potential safeguards measures to meet those objectives. ASTOR supported the IAEA in assessing how safeguards measures could be effectively implemented and provided recommendations with respect to developing such measures. Specific verification technologies were developed under other Member State Support Programme tasks. A summary report on the progress and status of safeguards for spent fuel encapsulation plants and geological repositories was completed by ASTOR in 2017. ASTOR also identified areas and actions that need to be accomplished to support safeguards implementation in final disposal facilities, such as (1) establish performance requirements for the design of safeguards technologies relevant to geological disposal of spent fuel, (2) determine specific information needs of states and operators regarding safeguards implementation for geological disposal of spent fuel and develop appropriate guidance, (3) determine specific information needs of IAEA inspectors and analysts and develop a guidance document that provides recommendations for implementing safeguards for a geological repository system under the state-level concept and (4) develop and test appropriate safeguards equipment (IAEA, 2017; Moran et al., 2018). While several measures and technologies related to verifying the geological disposal of spent fuel have been used by the IAEA at other facilities or are in development or testing, other technologies still need to be developed and tested. In addition, ASTOR identified the need for approaches to how information about disposed spent fuel and high-level nuclear waste should be managed, handled, organized, archived, read, interpreted and secured for the long term (for centuries after repository closure and beyond), including an international standard for states and facility operators on information management, data-retention methods and timescales for preserving safeguards data for geological repositories. The presentation will introduce the objectives of international nuclear material safeguards for the final disposal of spent nuclear fuel, highlight the current status of developments and discussions in terms of approaches and technologies for safeguarding geological repositories, and give an outlook on implementing safeguards for final disposal in Germany.

The use of muon radiography in safeguarding geological repositories

Muon radiography is a technique that harnesses naturally occurring cosmic radiation to noninvasively determine the density of an object of interest. The technique has many similarities to that of medical X-ray examinations and can supply detailed density maps of the object. We propose the application of muon radiography to aspects of the long-term monitoring of nuclear waste. In particular, muon radiography would provide valuable information on the overburden of a prospective underground geological repository and would be able to identify unknown features, such as undocumented underground passages. Similarly, muon tomography is capable of confirming that containers that have nominally been emptied are in fact empty. Such safeguard measures are important to maintain continuity of knowledge and to develop robust deterrent strategies against the removal of monitored nuclear material. The presentation focuses on the results of simulations that address some of these questions. Details of assumptions regarding the detector requirements and run times necessary to perform the imaging are discussed and results from the various removal and misuse scenarios are presented.

Histological study of an experimentally constructed decellularized rat lung as a model of whole organ three-dimensional natural scaffold

Introduction With the increase of end stage lung diseases and the great problems facing lung transplantation tissue engineering become a promising solution. The first step in lung engineering is to obtain a 3D Extracellular matrix lung scaffold via decellularization. Decellularization aims to remove cells from tissue ultrastructure while preserving the mechanical and biological properties of the tissue. Intact ECM provides critical cues for differentiation and migration of cells that are seeded onto the organ scaffold. Objectives This study aimed to obtain an intact and well-preserved ECM lung scaffold by decellularization of rat lungs. Methods Decellularization of lungs of ten Wistar rats was achieved by perfusing detergents through the pulmonary artery. The resultant scaffolds were fixed and analyzed histologically. Results It was found that the decellularization process effectively removed the cellular and nuclear material while retaining native the 3D ECM of lung tissue. The architecture of the collagen and elastic fibers networks were preserved as comparable to the native lungs. Furthermore, the basement membranes of the bronchiolar and interalveolar septa were intact. Conclusions This methodology is expected to allow decellularization of human lung tissues and permits future scientific exploration in tissue engineering.

MUF Calculation of Indonesian 10-MWt RDE Experimental HTGR Using Combined Uncertainty Approach

A safeguards assessment for the 10-MWt RDE Experimental HTGR needs to be established in order to fulfill the requirements needed to construct it. Methods and instruments used for the RDE’s nuclear material accounting and safeguards system are reviewed in this paper. Material unaccounted for (MUF) is calculated using the uncertainty of each method and instrument. The effectiveness of the safeguards system is examined by comparing the resulting MUF with the number of SQ ( = significant quantity, i.e. the approximate amount of nuclear material for which the possibility of manufacturing of a nuclear explosive device cannot be excluded). The total uncertainty from each KMP showed a number less than 10%. The number of MUF in each KMP according to total uncertainty showed a number below 1 kg of U-235 in one inventory period (~12 months). According to the number of MUF counted, it is impossible to reach 1 SQ if the diversion done is only by taking the advantage of MUF in the measurement. The result of total uncertainty and MUF calculation showed that the safeguards system and the material measurement designed for RDE is amendable. The sets of instruments and measurements designed will give a comprehensive data of each nuclear material in the RDE. The low number of MUF in comparison with the SQ showed that the RDE has a high proliferation resistance.