Economic Dispatch Model of Nuclear High-Temperature Reactor with Hydrogen Cogeneration in Electricity Market

Hydrogen produced without carbon emissions could be a useful fuel as nations look to decarbonize their electricity, transport, and industry sectors. Using the iodine–sulfur (IS) cycle coupled with a nuclear heat source is one method for producing hydrogen without the use of fossil fuels. An economic dispatch model was developed for a nuclear-driven IS system to determine hydrogen sale prices that would make such a system profitable. The system studied is the HTTR-GT/H2, a design for power and hydrogen cogeneration at the Japan Atomic Energy Agency’s High Temperature Engineering Test Reactor. This study focuses on the development of the economic model and the role that input data plays in the final calculated values. Using a historical price duration curve shows that the levelized cost of hydrogen (LCOH) or breakeven sale price of hydrogen would need to be 98.1 JPY/m3 or greater. Synthetic time histories were also used and found the LCOH to be 67.5 JPY/m3. The price duration input was found to have a significant effect on the LCOH. As such, great care should be used in these economic dispatch analyses to select reasonable input assumptions.

Cost Analysis of Nuclear Hydrogen Production Using IAEA-HEEP 4 Software

Hydrogen is a commercially important element. Basically, there are several methods of hydrogen production that have been commercially used, such as Steam Methane Reforming (SMR), High Temperature Steam Electrolysis (HTSE), and thermochemical cycles, like Sulphur-Iodine (SI). Among these methods, SMR is the most widely used for large-scale hydrogen production, with conversion efficiency between 74–85% and it has commercially used in some fertilizer industries in Indonesia. Steam reforming is a method to convert alkane (natural gas) compounds to hydrogen and carbon dioxide (synthetic gas) by adding moisture at high pressure and temperature (35-40 bar; 800-900°C). These hydrogen production technologies can be coupled with different nuclear reactors based on the heat required in the process. The High Temperature Gas-cooled Reactor (HTGR) using helium as a coolant, has a high outlet temperature (900°C), so it can potentially be used to supply for process heat for hydrogen production, coal liquefaction/gasification or for other industrial processes requiring high temperature heat. Hydrogen production cost from SMR method is influenced by a range of technical and economic factors. The fuel component of natural gas needed in the SMR method can be replaced by nuclear heat from a nuclear power plant (NPP) operating in cogeneration mode (i.e. simultaneous producing electric power and heat), hence contributing to the reduction of carbon dioxide in the process. In the SMR method, fuel costs are the largest cost component, accounting for between 45% and 75% of production costs. Therefore, there is opportune to assess the economics of hydrogen production by using nuclear heat. The economic evaluation is done by using IAEA HEEP-4 Software. The results comprise cost break up for 2 cases, coupling SMR process for hydrogen production with: (1) 2 HTGRs of 170 MWth/unit; and (2) 1 HTGR of 600 MWth/unit. The cost of hydrogen production is highly depend on the scale of the NPP as energy source and results indicated that hydrogen production cost of the 1 HTGR Unit600 MWth (Case 2) has a lower value (1.72 US$/kgH2), than the cost obtained when 2 HTGR units of 170 MWth each (case 1) are considered (2.72 US$/kgH2). For comparison, the hydrogen production cost by using SMR with carbon capture and storage (CCS) with natural gas as fuel is 2.27 US$/kgH2.

Application of Photogrammetric Methods for Geotechnical Monitoring of Emergency Buildings and Structures

Постановка задачи. Одной из актуальных научно-технических задач в строительстве является совершенствование методов мониторинга состояния строительных конструкций (в том числе в стесненных условиях работы) при строительстве уникальных сооружений и объектов незавершенного строительства, обеспечивающих надежный контроль их качества, устойчивости и безопасности. Довольно часто возникают условиях, при которых нет возможности выполнить полноценный мониторинг отдельных видов деформаций строительных конструкций традиционными методами. Требуется разработка универсальных, надежных и удобных методов контроля различных геометрических параметров сооружения с целью своевременного принятия мер по обеспечению стабильности и устойчивости сооружения, чтобы исключить переход сооружения в ограниченно работоспособное или в аварийное состояние. Результаты и выводы. Предложенные в работе методы определения деформаций и качества изготовления строительных конструкций с использованием метрической фотосъемки позволяют провести полноценный мониторинг их технического состояния с необходимой точностью. Все перечисленные в статье способы контроля отрабатывались и проверялись на зданиях и сооружениях законсервированной Воронежской атомной станции теплоснабжения. Statement of the problem. One of the urgent scientific and technical problems facing construction is the improvement of methods for monitoring the state of building structures (including under confined working conditions) during the construction of unique structures and objects of unfinished construction, ensuring reliable control of their quality, stability and safety. Oftentimes, conditions arise where it is impossible to perform a full types of deformations of building structures using traditional methods. It is required to develop universal, reliable and convenient methods for controlling various geometric parameters of the structure in order to take timely measures to ensure the stability and stability of the structure in order to exclude the transition of the structure to a partially operable or emergency state. Results and conclusions. The suggested methods for determining deformations and the quality of manufacturing of building structures using metric photography make it possible to conduct a full-fledged monitoring of their technical condition with the required accuracy. All the control methods listed in the article were developed and tested on the buildings and structures of the mothballed Voronezh nuclear heat supply station.

Morphological and molecular characterisation of Punctodera mulveyi n. sp. (Nematoda: Punctoderidae) from a golf course green in Oregon, USA, with a key to species of Punctodera

Summary Punctodera mulveyi n. sp. is described and illustrated from turf grass (Poa annua) in golf course greens with other fescues in Bandon, Coos County, Oregon, USA. Females and cysts are characterised by a saccate, globose to ovoid or pear-shaped body with a protruding neck. The cuticle has a lace-like pattern of ridges and heavy punctations on the subsurface. Cysts have distinctive vulval and anal circumfenestral patterns with heavy bullae scattered around the fenestral area, these being absent in young cysts. Second-stage juveniles (J2) vermiform, tapering to a long and cylindrical tail with a bluntly rounded to occasionally clavate tail terminus. Morphologically the new species resembles all known species of Punctodera using both light microscopy and scanning electron microscopy observations, but differs from the other species either by the J2 body and stylet length, shape of head, tail and tail terminus, female and male stylet or spicule length, and in having distinctive vulval and anal circumfenestral patterns in the cysts. Molecular analysis with sequence alignments and phylogenetic trees of ITS rDNA, nuclear heat shock protein 90 and mitochondrial COI sequences separated P. mulveyi n. sp. from P. matadorensis, P. punctata, P. stonei and P. chalcoensis, but 18S and 28S were relatively conserved with a few bp differences and there were insufficient Punctodera species sequences to give strong support to a new species designation. A morphologically most closely related species, P. stonei from Canada, further supported the status of P. mulveyi n. sp. An identification key to all five nominal species of Punctodera is given.

The assessment of nuclear hydrogen cogeneration system (NHCS) for CO2 conversion to urea fertilizer

This paper reviews the application of a nuclear hydrogen cogeneration system (NHCS) for conversion of carbon dioxide (CO2) to urea fertilizer. The NHCS is powered by high temperature gas cooled reactor (HTGR)with 2x600 MWt which is sufficient to produce hydrogen and heat energy to convert CO2 from coal-fired power plants with a power of 90 MWe to urea fertilizer of 1725 tons per day. As a source CO2, a coal-fired power plant is built near NHCS. Compared to conventional fertilizer plant, the NHCS application can save natural gas by 21.25x106 MMBTU/year, with a potential reduction in CO2 emission rate of 1.66x106 tons/year. Besides, there is still nuclear heat remaining at about 425.65 MWt which is equivalent to 140.46 MWe of electricity, and 90 MWe of electricity from coal-fired power plants that can be connected to electric grid. The paper also discusses the significance of the combination of NHCS and the technology of CO2 conversion which is expected to play an important role in the industry in the future as an environmentally friendly approach.