Nuclear Utilities Research Articles

Physics-informed Reinforcement Learning optimization of PWR core loading pattern

The nuclear sector represents the largest single source of carbon-free energy in the United States. Nevertheless, keeping existing nuclear assets competitive on the grid is key to their ability to continue to provide dispatchable clean energy along side renewable generation. Optimizing the fuel cycle cost through the optimization of core loading patterns is one approach to addressing this lack of competitiveness. However, this optimization task involves multiple objectives and constraints, resulting in a vast number of candidate solutions that cannot be explicitly solved. While stochastic optimization (SO) methodologies are utilized by various nuclear utilities and vendors for fuel cycle reload design, manual design remains the preferred approach. To advance the state-of-the-art in core reload patterns, we have developed methods based on Deep Reinforcement Learning for single and multi-objective optimization. Previous research has laid the groundwork for these approaches and demonstrated its ability to discover high-quality patterns within a reasonable timeframe. Moreover, RL methods have shown superiority against SO in the multi-objective settings. In this paper, we introduce an innovative paradigm by incorporating multi-objective RL, interpretable AI, and physics knowledge to further improve the performance of the algorithms. When the problem increases in complexity, the classical single-objective sometimes failed to even found feasible solutions. Leveraging physic-information becomes pivotal to find high-quality and more diverse solutions faster. These findings motivate incorporation of more physics to further aid in the quest of surpassing human intelligence. Future work will focus on scaling this method and addressing fuel performance and control rod limits to demonstrate that these new designs can be considered for a real reactor.

An Estimation of the Monetary Value of the Person-Sievert Useful for Occupational Radiological Protection within the Healthcare System of Sweden.

The As Low As Reasonably Achievable (ALARA) principle includes taking into account economic and societal factors. To consider these factors, decision-aiding techniques such as cost-benefit analysis were introduced by the International Commission on Radiological Protection (ICRP) 50 y ago. Over the years, developments in health economics have led to new ways of deriving the concept of a value of a statistical life (VSL), which now is influencing the monetary value assigned to a unit of collective dose for radiological protection purposes (the α value) used in cost-benefit analyses. The aim of the present study was to estimate an α value useful for occupational radiological protection within the healthcare system of Sweden. A survey based on the stated preference approach was developed and sent to staff who are exposed to ionizing radiation at their work in Region Västra Götaland (Sweden). The survey essentially contained two scenarios: the respondents' willingness to pay for measures against radon exposure at home and their willingness to accept compensation for x-ray exposure at work. Answers from 718 respondents were collected. In the sensitivity analysis of the survey, the overall median VSL based on the two scenarios was calculated to be $50 million (IQR $10 to 363 million). The corresponding α value was established to $1,600 person-mSv -1 ($2,100 person-mSv -1 if excess burden of taxes is excluded). The recommended α value is in the high end compared to other studies but within the interval of values being used by nuclear utilities today. The α value should be seen in the light of ICRP's recommendation about stakeholder involvement as an important part of the optimization process.

Edukasi Kemampuan Geospasial Badan Pengawas Tenaga Nuklir

Background: The Nuclear Energy Supervisory Agency (BAPETEN) is responsible for supervising nuclear utilization in Indonesia in collaboration with Linkeu Regional Government in a Geospatial learning process. This activity aims to prepare a base map and land capability analysis map for constructing a Nuclear Power Plant. Method: The training activity ran two days (2-3 August 2023) in Jakarta with Arc GIS 10.8 Software. The map used in making the base map is the Madiun Regency Regional Map, while the analysis map uses the Kendal Regency area. Results: Participants were able to create a base map with the target base map layout according to cartographic rules. Participants prepared land suitability analysis maps based on criteria from several thematic maps using the Weighted Overlay process. Conclusion: This activity produces base and land suitability maps that fulfill cartographic aspects. Participants understand the mapping process, proven by the post-test score above 80, and participant satisfaction with this activity is 100%.

Grid interconnections and decarbonization pathways for carbon neutrality of Northeast Asia

As the three major greenhouse gas emitters in Northeast Asia (NEA), China, South Korea, and Japan, have joined the global carbon neutrality movement, this study examines interstate power transmissions between the countries to be considered for optimal technology pathways towards the net zero emission target. Using a bottom-up least-cost energy system model, intertemporal investment decisions are made between 2015 and 2065 in 10-year time steps subject to short-term/long-term emission targets in a range of carbon prices (0,100,200,300 USD/tCO2). Results show that under the carbon neutrality target, interstate power trade enables earlier carbon phaseout at a lower cost by increasing renewables utilizations and reduces investment burdens for high-cost carbon-neutral technologies like hydrogen. We find grid interconnections increase renewable penetrations at all nodes, while carbon pricing above 200 USD/tCO2 is required to ensure all participating nodes benefit from earlier carbon reduction. Ambitious carbon pricing is also important for closing gaps in emission impacts of short-term and long-term emission targets, calling for urgent actions to remove market distortion in power sectors. Lastly, sensitivity analysis to trade limits and nuclear utilization shows trade makes a greater contribution to carbon phaseout with relaxed trade terms and nuclear deployment.

Tinjauan Literatur Pemanfaatan Nuklir dalam Pengurangan Sampah Plastik

Solid domestic waste is a priority sector in reducing greenhouse gas emissions (GHG) in Indonesia. Plastic waste is a type of solid domestic waste that will contribute up to 23.57% of waste generation in Indonesia in 2022. The aim of this paper was a general review of the use of nuclear technology and aspects related to plastic waste management in supporting the reduction of GHG emissions. The research method is a literature study from regulatory aspects, international recommendations/ guidelines, and several related studies. Conventional plastic waste management through 3R principles through reducing, reusing, and recycling. Nuclear utilization can contribute to plastic waste management, one of which is irradiation techniques. The expected interaction of radiation with plastic is depolymerization and cross-linking. Utilization of irradiation technology in reducing plastic waste directly by depolymerizing plastic waste. In the indirect process, plastic is used as a substituent for other materials, such as the manufacture of Fiber Reinforced Concrete (FRC), and then irradiated with a specific dose. Increasing the radiation dose will increase the number of chain cleavage/degradation and increase the degree of crystallinity, but inversely proportional to the molecular weight obtained will decrease. Irradiation technology is proven to increase the mechanical strength, compressive strength, and modulus of elasticity in FRC. The current regulatory and licensing aspects cover irradiation technology (irradiators). It's just that the challenges in implementing irradiation technology in processing plastic waste include energy requirements in the operation of irradiation technology (irradiators) and a reduction in efficiency. Keywords: nuclear, waste, plastic, irradiation, radiation dose

Equipment Reliability Process in Krško NPP

To ensure long-term safe and reliable plant operation, equipment operability and availability must also be ensured by setting a group of processes to be established within the nuclear power plant. Equipment reliability process represents the integration and coordination of important equipment reliability activities into one process, which enables equipment performance and condition monitoring, preventive maintenance activities development, implementation and optimization, continuous improvement of the processes and long term planning. The initiative for introducing systematic approach for equipment reliability assuring came from US nuclear industry guided by INPO (Institute of Nuclear Power Operations) and by participation of several US nuclear utilities. As a result of the initiative, first edition of INPO document AP-913, ‘Equipment Reliability Process Description’ was issued and it became a basic document for implementation of equipment reliability process for the whole nuclear industry. The scope of equipment reliability process in Krško NPP consists of following programs: equipment criticality classification, preventive maintenance program, corrective action program, system health reports and long-term investment plan. By implementation, supervision and continuous improvement of those programs, guided by more than thirty years of operating experience, Krško NPP will continue to be on a track of safe and reliable operation until the end of prolonged life time.

Nuclear Heat Utilization For Natural Gas Steam Reforming To Produce Hydrogen

The assessment of nuclear heat utilization for natural gas steam reforming to produce hydrogen has been carried out. Most of hydrogen production in the world, is produced by steam reforming of natural gas. This process is an endothermic reaction at high temperature that needs a huge amount of heat energy to proceed the reaction. Conventionally, the heat energy needed is supplied by direct burning of fossil fuel. If the huge amount of those heat energy can be substituted by nuclear process heat, some advantages can be obtained such as, reducing combustion of fossil fuels that give implication of significant decreasing of CO2 emission to the environment. On application of nuclear process heat to steam reforming of natural gas, there are some inferior conditions related to the limitation of temperature and pressure provided by nuclear reactor which directly gives impact on lower thermal efficiency (~50%) compared to the fossil-fuelled plant (80-85%). Some modification design and operation of reformer can improve the lack condition, and capable to increase the thermal efficiency of nuclear heated natural gas steam reformer become about 78%.

The Implementation of the Precautionary Principle in Nuclear Safety Regulation: Challenges and Prospects

The precautionary principle has been implemented in many fields including environment protection, biological diversity, and climate change. In the field of international nuclear safety regulation, the implementation of this principle is in an ongoing process. Since Japan declared to discharge Fukushima nuclear waste water into the ocean, the precautionary principle was put on the stage, and some debates are invoked on it. As is observed by this article, the precautionary principle has not been effectively implemented in nuclear safety regulation, specifically in nuclear safety law making, law enforcement, and judicial application. The reasons can be found from two main challenges: indeterminacy of perceived risk level required to justify precautionary action and hard balance of national interest and community interest in nuclear safety. In a long-term perspective, the framework of international nuclear safety regulation has to respond to these challenges, both by clarifying the precautionary principle in legal binding nuclear safety documents and moving towards a more transparent, fair, and effective enforcement regime in order to promote safer, more sustainable, and efficient civilian nuclear utilization around the world.

Comparative study of GSR Part 2 and ISO 45001:2018

Government Regulation Number 54 the Year 2021 regarding Safety and Security of Nuclear Installations requires the licensee to establish and implement a safety and security management system for nuclear installations. Currently, a revision is being made to Bapeten Chairman Regulation No. 4 the Year 2010 regarding the Management System for Facilities and Activities of Nuclear Energy Utilization following GSR Part 2 issued by IAEA as the latest guideline for the nuclear safety management system. On the other hand, the industrial world is familiar with the occupational health and safety management system (OHSMS), which was once popular with the OHSAS 18001 series and has now been migrated to ISO 45001. Therefore, a study was conducted to examine the clauses in ISO 45001:2018 as the latest international OHSMS standard that can meet the requirements in GSR Part 2. The study results concluded that the clauses in ISO 45001:2018 could meet most of the provisions contained in GSR Part 2. However, several other parts still need to be added, namely the expansion of the fundamental objectives of the management system to include public and environment, development of the scope of resources to include funding, demonstration of safety leadership to each manager, and explanation of the implementation of safety culture. Keywords: Management System, GSR Part 2, ISO 45001:2018, Occupational Health and Safety.

Identification of the need for unmanned radiation monitoring facilities in the radiation monitoring of research reactors in Indonesia

The facility’s licensee conducts environmental radiation monitoring in nuclear facilities to monitor radiation exposure in the facility’s vicinity. This activity is carried out also to monitor radiation release as a result of nuclear reactor operation. Aside from that, monitoring also works as a device to monitor radioactive release in a nuclear emergency. Therefore, the radiation monitoring system is crucial in nuclear utilization facilities to determine the number of radiation exposure to the surrounding environment. However, the existing stationary monitoring system has a risk of being unable to work if the system is down in case of natural disaster occurs. One way to mitigate this risk is to deploy an unmanned radiation monitoring system to monitor radiation exposure without putting personnel at risk. To define a suitable unmanned radiation monitoring system, identification of facilities and infrastructure required to design an unmanned radiation monitoring system for a research reactor in Indonesia is carried out. Facilities and infrastructure needed for unmanned radiation monitoring systems are unmanned aerial vehicles, radiation detector, control and communication module, navigation system, and software for the control system. These required facilities and infrastructure are then specified to determine the necessary specification for monitoring research reactor in Indonesia. The facilities’ required specifications are unmanned aerial vehicles with rotary-wing type, CdZnTe Detector, and GPS/GLONASS based navigation system. For infrastructure specification, control and communication module and software for the control system is not specified in how the system could meet the expected required performance rather than in detail. However, the system must provide and process measurement data in real-time to be presented in a radiation heatmap. Keywords: Identification, Radiation Monitoring, Unmanned

Towards standardized nuclear reactors: Seismic isolation and the cost impact of the earthquake load case

Nuclear energy has a key role to play in global decarbonization. Impediments to the widespread deployment of reactors are their projected high capital cost and levelized cost of energy, and time required to analyze, design, license, construct, and commission them. The earthquake load case is a key cost driver for a new build nuclear plant, because near-surface soils and seismic hazard are different at each site, requiring site-specific analysis, design, engineering, qualification, licensing, and regulatory review, essentially making every design First-of-a-Kind (FoaK). To enable deployment at the scale needed for deep decarbonization, the cost and time impact of the seismic load case must be significantly mitigated, and plants must be standardized. Seismic base isolation has been proven to considerably reduce the earthquake response of structures and equipment but has yet to be applied to a nuclear power plant in the United States, in part because the financial impacts, positive or negative, are not known. Because there are no recent non-proprietary data to characterize the influence of the seismic load case on capital cost, it is difficult to confidently quantify the financial benefits of seismic isolation.Scheme-level designs of two fundamentally different advanced reactor buildings were developed to assemble cost data on the influence of the seismic load case. Both buildings were equipped with three bespoke pieces of safety-related equipment and analyzed for incremented levels of earthquake shaking to quantify the seismic penalty on equipment, in terms of vessel weights and horizontal accelerations. Using analysis results, a questionnaire was developed and transmitted to nuclear utilities, reactor developers, engineers, and equipment suppliers to collect cost data on engineering and fabrication costs for these unique pieces of safety-class equipment. Synthesis of the cost data showed that the seismic load case significantly affects the capital cost (sum of engineering and fabrication cost) of safety-class equipment, with engineering costs being comparable to fabrication costs. Standardization of safety-class equipment is made possible by seismic isolation, that is, equipment designed for minimal seismic robustness can resist earthquake shaking at a site of much higher seismic hazard. The average reduction in the capital cost of the safety-related equipment, enabled by seismic isolation, is a factor of two for FoaK equipment and a factor of five for standardized equipment.

The economic organization of decommissioning nuclear power plants – an institutional economic analysis with case studies in the US, UK, and Germany

Abstract. The process of decommissioning nuclear power plants (NPP) is a multidisciplinary task that involves technical, regulatory, financial, and organizational activities. In order to fully decommission and subsequently release a reactor from regulatory control, a multitude of tasks need to be realized, i.e., defueling the reactor core, storing spent nuclear fuel, decontamination work, deconstructing conventional buildings, etc. Decommissioning is thus an intricate good that includes the supply of a variety of services, which must be produced upstream or offered in parallel. This paper provides an economic analysis of different options of organizing (or: governing) the decommissioning process, so as to minimize the total costs for society, while of course respecting security standards set by the regulator. The costs of providing decommissioning result from the production and transaction costs. The former are largely determined by technical aspects and development of the decommissioning process, and the possibility of exploiting economies of scale and scope. Transaction costs, on the other hand, mainly result from coordination between the different tasks as well as the involved actors, often private and public actors with different target systems and equipped with different resources. Transaction cost economics (TCE) is used to identify coordination areas and applied to formulate propositions on how nuclear utilities, decommissioning service suppliers, and waste management companies can establish vertical coordination. Transactions in the decommissioning process take place in a regulated environment and are governed, at least partially, by some public actors. In general, market governance is often assumed to be the most efficient governance structure, but in this context, our hypothesis is that institutional constraints, uncertainty, and factor specificity may call for other governance forms (Williamson, 1985). First analyses of the actors and the potential of the decommissioning market suggest an only slowly evolving market with only a few specialized companies and their subsidiaries able to provide technologically demanding services (Seidel and Wealer, 2015; Volk et al., 2019), while small and medium companies are confronted with high barriers to entry into the market (EC, 2018). Nuclear countries have implemented quite different organizational models, varying from specific national decommissioning strategies implemented by a public agency to a relatively free choice of the strategy for plant operators (Wealer et al., 2019). In some countries, procurement laws have been put into place to create a competitive market. However, as the decommissioning market has evolved, challenges to the competitive ideal have arisen, i.e., market concentration and asymmetries of information. This oligopolistic structure combined with the increase in demand for decommissioning services gives rise to concerns regarding the functionality of the market. There are also key logistical issues that must be addressed, including supply chain bottlenecks and procurement strategies. A unified finding is that decommissioning is highly interlinked with nuclear waste management and is also the main source of uncertainty in terms of cost as well as the length of the decommissioning process, as the missing disposal solutions for high-level radioactive waste render it impossible to release the nuclear power plants from regulatory control.

Baseline levels of radionuclides concentration in the sea of Wakatobi and Kendari

The importance of an information about the baseline value of radionuclides in the sea of Wakatobi and Kendari to see how large the input or contamination of radionuclides in the area. This contamination can come from waste human activities such as industry and nuclear utilization activities that are biased carried by seawater currents and air gusts. Natural and anthropogenic radionuclide concentrations in the Wakatobi and Kendari seas have been measured using a Gamma spectrometer (HPGe).The monitoring results show that both 226Ra, 232Th, 40K and 137Cs indicate that they are in normal condition and do not exceed the safe limit. The data presented in this study will be very important and useful to be used as basic data in mapping the improvement of radionuclide contamination in the area.

NMB4.0: development of integrated nuclear fuel cycle simulator from the front to back-end

Nuclear Material Balance code version 4.0 (NMB4.0) has been developed through collaborative R&D between TokyoTech&JAEA. Conventional nuclear fuel cycle simulation codes mainly analyze actinides and are specialized for front-end mass balance analysis. However, quantitative back-end simulation has recently become necessary for considering R&D strategies and sustainable nuclear energy utilization. Therefore, NMB4.0 was developed to realize the integrated nuclear fuel cycle simulation from front- to back-end. There are three technical features in NMB4.0: 179 nuclides are tracked, more than any other code, throughout the nuclear fuel cycle; the Okamura explicit method is implemented, which contributes to reducing the numerical cost while maintaining the accuracy of depletion calculations on nuclides with a shorter half-life; and flexibility of back-end simulation is achieved. The main objective of this paper is to show the newly developed functions, made for integrated back-end simulation, and verify NMB4.0 through a benchmark study to show the computational performance.

A study of the nuclear natural resources utilization in open and closed fuel cycles: nuclear energy a sustainable and renewable source of energy

In this work, the use of natural resources was analyzed using a simplified methodology and assuming calculation conditions close to the real ones, to assess the sustainability of the nuclear source and the efficiency in the use of these resources. For the analysis of open fuel cycles, four reactors were selected, these being the Pressurized Water Reactor (PWR) and Pressurized Heavy Water Reactor (PHWR), two Generation II reactors commonly used until today, the advanced Generation III reactor AP1000 and the conceptual reactor AP-Th 1000. For closed fuel cycles, the variation of the utilization of the natural resource alongside with the variation of the conversion factor were evaluated, parameterized by the burnup. It was observed that the Generation II reactors use only 1% of the natural resources and, despite technological advances, the Generation III reactor did not show a significant increase in comparison to the former. Although the closed fuel cycle includes recycling the burnt fuel from thermal reactors, it exploits only about 10% of the resources. Major improvements are observed in Fast Breeder Reactors, being able to obtain a use of almost 100% with the increase of the burning and the minimization of losses. Although the feasibility of using thorium as a nuclear fuel has been proven, it would be better used in a closed cycle, as in the self-sustainable Liquid Fluoride Thorium Reactor (LFTR), a Generation IV reactor that can transform the nuclear energy in a sustainable and renewable source of energy.

TINDAK PIDANA LINGKUNGAN HIDUP DALAM KAITANNYA DENGAN PEMANFAATAN ENERGI NUKLIR

ABSTRACT The development of technology in the world lately is very rapid, nuclear technology is widely applied in various fields. By utilizing nuclear energy, humans get huge benefits. The use of nuclear technology is also not spared from accidents. Nuclear accidents are caused by too much energy which is often very dangerous. In relation to nuclear issues with the legal consequences of the use of nuclear technology and environmental criminal liability. This research uses a normative juridical approach that is descriptive in nature with existing literature and regulatory studies relating to the environment and nuclear. The use of nuclear energy cannot be separated from the consequences of the law. due to the law in the form of a nuclear accident that causes a loss originating from radiation or combined radiation. This has an impact on the environment in the form of damage that has a negative effect on humans and ecosystems in general. Related to the legal consequences caused, it should be held liable according to law which in this case is criminally. In nuclear accidents related to the environment, individuals and corporations may be held liable for criminal penalties in accordance with the PPLH Law in the form of basic criminal penalties for individuals and also corporations or legal entities with principal penalties in the form of criminal fines and additional penalties in the form of confiscation of evidence, compensation, compensation, restitution, repair of damage resulting from criminal acts. The handling of this corporation is clarified by the Supreme Court Regulation of the Republic of Indonesia Number 13 of 2016 concerning Procedures for Handling Criminal Acts by Corporations due to obscurity in the criminalization of corporations in the PPLH Law. As for punishment as a result of nuclear utilization which has an impact on the environment its nature is ultimum remedium or as a final remedy. Keywords: Nuclear Utilization, Nuclear Accidents, Criminal Liability.

The values and the uses of the reference monetary value of the man.sievert. Results of an international survey

For complex radiation protection project, decision-aiding techniques, such as Cost-Benefit Analysis can be used. In 1973, the International Commission on Radiological Protection introduced the “reference monetary value of the man.sievert” to convert the benefit of a radiation protection option (averted exposure) in monetary term for comparison with it is cost. In 2017, an international survey has collected the reference monetary values of nuclear utilities and regulatory authorities. This article presents the data collected and analyzes them. Over the 220 reactors who answered, 176 (80%) are using the concept, expressing its longevity and relevance for optimization purposes. The utilities can use single value or set of reference values varying with the level of exposure. This survey also highlights the emergence of mixed and flexible systems. The collected values are largely spread (ratio 1:10 at least) and this is the opportunity to discuss the influence of the method used to calculate the reference value and notably the related concept of the Value of a human Statistical Life (VSL).

Clean Fuel from Nuclear Power

Abstract The current commercial hydrogen production has a significant carbon footprint. Now, projects co-funded by the U.S. Department of Energy and commercial nuclear utilities with operating nuclear power facilities aim to change that by exploiting the capabilities of nuclear power plants. This article delves into four projects aimed at demonstrating technology to make hydrogen from water on an industrial scale using energy from an operating commercial nuclear power plant.

Citizen Scientist: Frank von Hippel’s Adventures in Nuclear Arms Control PART 8. Nuclear-reactor Safety Again

ABSTRACT The Fukushima accident of 2011 pulled von Hippel back into the reactor-safety world. He was invited to join a Congressionally-mandated four-year study of the lessons that could be learned from the Fukushima accident to improve the safety of US nuclear plants. During that study he learned more about both a much worse accident that almost happened at Fukushima, and about how the US Nuclear Regulatory Commission had come to use “risk-informed regulation” as a way to avoid requiring costly safety upgrades opposed by US nuclear utilities. He campaigned unsuccessfully at both the national and state levels to move the nuclear utilities away from densely packed spent fuel pools by moving fuel that had cooled for more than five years to dry-cask storage. He also promoted on-site dry-cask storage in Japan and South Korea as an alternative to reprocessing. This last chapter ends with some stories of his father, also a physicist, who would not be intimidated and who was a leader in the development of the field of materials science and engineering.

Safety aspects of spent fuel management in nuclear power plants during transition to decommissioning

The main purpose of this paper is to introduce the system/equipment maintain experience of nuclear power plants entering to decommissioning during the post-operation transition phase (spent fuel wet storage). In the early stage of the post-operation transition phase, the reactor must first enter to a permanent shutdown state, and all spent fuel would have been taken out of the reactor and been transferred to the spent fuel pool (SFP). Before moving all spent fuel to the dry storage facility, active cooling of the spent fuel pool water is required for maintaining safety in order to prevent spread of radioactive contamination and to ensure spent fuel storage safety. With decrease in decay heat and sources of radiation, industry experience shows total risks related to nuclear energy or radiation safety during SFP storage period shall be significant lower than that during commercial operations. Therefore, the changes made to spent fuel pool cooling and cleanup systems (SFPCCSs), makeup water systems, and backup electrical systems to comply with the regulatory requirements could further provide a simpler and more cost-effective operating characteristic. Referring to the renew version of licensing basis documents preparing by various nuclear utilities, this paper focuses on summarizing the practical activities of spent fuel management in detail during the spent fuel wet storage period.