scholarly journals Preliminary Study on HTR-10 Operating in Higher Outlet Temperature

2021 ◽  
Vol 2048 (1) ◽  
pp. 012035
Author(s):  
Yanhua Zheng ◽  
Bing Xia ◽  
Zhipeng Chen ◽  
Han Zhang ◽  
Jun Sun
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Carbon Dioxide Emissions ◽  
Heat Supply ◽  
Outlet Temperature ◽  
Helium Temperature ◽  
Acceptance Criteria ◽  
Hydraulic Design ◽  
Safety Features ◽  
High Temperature Gas

Abstract High Temperature Gas-cooled Reactor (HTGR), which has well-known safety features and high temperature heat supply capability, is expected to be widely used for heat supply and technology heat utilization including the hydrogen production, and so contributing to the reduction of carbon dioxide emissions in various sectors. The 10 MW High Temperature gas-cooled test Reactor (HTR-10) had been constructed and operated in China as a pilot plant to demonstrate the inherent safety features of the modular HTGR. The first criticality of HTR-10 at air condition was realized on December 1, 2000, and the full power operation for 72 h on January 29, 2003. Supported by Chinese National S&T Major Project, HTGR for hydrogen production are now being studied. The physical and thermal hydraulic design to raise the outlet helium temperature of the HTR-10 reactor core from 700 °C to 850~1000 °C is carried out. In this paper, the preliminary thermal hydraulic design of the HTR- 10 with the outlet helium temperature of 950 °C (HTR-10H) is introduced. The power density distribution, the fuel temperature distribution and the reactor pressure vessel (RPV) temperature are studied to identify what need to be focused on next. Besides, the typical DLOFC accident has been studied to evaluate the safety feature of the HTR-10 operating under higher core temperature and outlet temperature. The preliminary results show that, operated at the higher outlet helium temperature, the original acceptance criteria for HTR-10 will be challenged. In the future, the design optimization, as well as the possible modification of these acceptance criteria, which were set more than two decades ago, should be studied based on the current knowledge of the fuel element properties and structure material properties.

Status and Future Development for Nuclear Cogeneration System GTHTR300C

2013 ◽  
Author(s):  
Xing L. Yan ◽  
Hiroyuki Sato ◽  
Hirofumi Ohashi ◽  
Yukio Tachibana ◽  
Kazuhiko Kunitomi
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Hydrogen Production ◽  
Future Development ◽  
Heat Supply ◽  
Nuclear Reactor ◽  
Industrial Process ◽  
Outlet Temperature ◽  
Commercial Plant ◽  
Test Reactor

GTHTR300C is a small modular reactor based on a 600 MWt high temperature gas reactor (HTGR) and intended for a number of cogeneration applications such as process heat supply, hydrogen production, steelmaking, desalination in addition to power generation. The basic design has been completed by JAEA together with Japanese heavy industries. The reactor design and key plant technologies have been validated through test reactor and equipment verification. Future development includes demonstration programs to be performed on a 50 MWt system HTR50S. The demonstration programs are implemented in three steps. In the first step, a base commercial plant for heat and power is to be constructed of the same fuel proven in JAEA’s successful 950°C, 30 MWt HTGR test reactor and a conventional steam turbine such that the construction can readily proceed without major development requirement and risk. Beginning in the second step, a new fuel presently being developed at JAEA is expected to be available. With this fuel, the core outlet temperature is raised to 900°C for purpose of demonstrating more efficient gas turbine power generation and high temperature heat supply. Added in the final step is a thermochemical process to demonstrate nuclear-heated hydrogen production via water decomposition. A licensing approach to coupling high temperature industrial process to nuclear reactor will be developed. The designs of GTHTR300C and HTR50S will be presented and the demonstration programs will be described.

scholarly journals Temperature Response of the HTR-10 during the Power Ascension Test

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Fubing Chen ◽  
Yujie Dong ◽  
Zuoyi Zhang
Keyword(s):  
High Temperature ◽  
Temperature Response ◽  
Temperature Limit ◽  
Reactor Power ◽  
Helium Pressure ◽  
Outlet Temperature ◽  
Fuel Temperature ◽  
Comparison Results ◽  
Safety Features ◽  
High Temperature Gas

The 10 MW High Temperature Gas-Cooled Reactor-Test Module (HTR-10) is the first High Temperature Gas-Cooled Reactor in China. With the objective of raising the reactor power from 30% to 100% rated power, the power ascension test was planned and performed in January 2003. The test results verified the practicability and validity of the HTR-10 power regulation methods. In this study, the power ascension process is preliminarily simulated using the THERMIX code. The code satisfactorily reproduces the reactor transient parameters, including the reactor power, the primary helium pressure, and the primary helium outlet temperature. Reactor internals temperatures are also calculated and compared with the test values recorded by a number of thermocouples. THERMIX correctly simulates the temperature variation tendency for different measuring points, with good to fair agreement between the calculated temperatures and the measured ones. Based on the comparison results, the THERMIX simulation capability for the HTR-10 dynamic characteristics during the power ascension process can be demonstrated. With respect to the reactor safety features, it is of utmost importance that the maximum fuel center temperature during the test process is always much lower than the fuel temperature limit of 1620°C.

Thermodynamic Analysis of Power Generation Cycles With High-Temperature Gas-Cooled Nuclear Reactor and Additional Coolant Heating Up to 1600 °C

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Michał Dudek ◽  
Zygmunt Kolenda ◽  
Marek Jaszczur ◽  
Wojciech Stanek
Keyword(s):  
Energy Efficiency ◽  
High Temperature ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Electric Energy ◽  
High Energy ◽  
Medium Size ◽  
Outlet Temperature ◽  
High Temperature Gas

Nuclear energy is one of the possibilities ensuring energy security, environmental protection, and high energy efficiency. Among many newest solutions, special attention is paid to the medium size high-temperature gas-cooled reactors (HTGR) with wide possible applications in electric energy production and district heating systems. Actual progress can be observed in the literature and especially in new projects. The maximum outlet temperature of helium as the reactor cooling gas is about 1000 °C which results in the relatively low energy efficiency of the cycle not greater than 40–45% in comparison to 55–60% of modern conventional power plants fueled by natural gas or coal. A significant increase of energy efficiency of HTGR cycles can be achieved with the increase of helium temperature from the nuclear reactor using additional coolant heating even up to 1600 °C in heat exchanger/gas burner located before gas turbine. In this paper, new solution with additional coolant heating is presented. Thermodynamic analysis of the proposed solution with a comparison to the classical HTGR cycle will be presented showing a significant increase of energy efficiency up to about 66%.

Conceptual Structure Design of High Temperature Isolation Valve for High Temperature Gas Cooled Reactor

2010 ◽  
Author(s):  
Shoji Takada ◽  
Kenji Abe ◽  
Yoshiyuki Inagaki
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Production System ◽  
Conceptual Structure ◽  
Structure Design ◽  
Radioactive Material ◽  
Normal Operation ◽  
Temperature History ◽  
Allowable Limit ◽  
High Temperature Gas

The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor (HTGR) connected with a hydrogen production system, that is, protection of radioactive material release from the reactor to the hydrogen production system and combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. The HTIV used in the helium condition over 900 °C, however, has not been made for practical use yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because high temperature helium gas over 900 °C flows inside the valve. Inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of seat. The numerical analysis was carried out to estimate temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900 °C to the root, and the thermal stress locally increased at the root of the seat which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing thickness of the connecting part and increasing the temperature of valve box to around 350 °C. The stress also increased at the top of the seat. Creep analysis was also carried out to estimate a creep-fatigue damage based on the temperature history of the normal operation and the depressurization accident.

Study on Emergency Action Levels of the Modular High Temperature Gas-Cooled Reactor

2017 ◽  
Author(s):  
Xiaochuan Zang ◽  
Tao Liu
Keyword(s):  
High Temperature ◽  
Fission Product ◽  
Operating Mode ◽  
Inherent Safety ◽  
Pressurized Water ◽  
Plant Safety ◽  
Water Reactors ◽  
Safety Features ◽  
Action Levels ◽  
High Temperature Gas

The emergency action level (EAL) scheme for a modular high temperature gas-cooled reactor (HTR) plant refers to the generic EAL development guidance for pressurized water reactors (PWR) with HTR modification due to its design issues. Based on reactor’s accidents analysis and consequence assessment, EAL scheme of HTR is established through the steps of category and classification. Four emergency classes are set for HTR consisting of U (Emergency Standby), A (Facilities Emergency), S (Site Area Emergency) and G (General Emergency). The Recognition Category of Initiating Condition (IC) and EAL contains A - Abnormal Rad Levels / Radiological Effluent, F - Fission Product Barrier, H - Hazards and Other Conditions Affecting Plant Safety, S - System Malfunction. The methodology for development of EALs for HTR on Fission Product Barrier and System Malfunction has some differences from PWR’s due to differences on operating mode, inherent safety features and system characteristics.

scholarly journals Analysis of a High Temperature Gas-Cooled Reactor Powered High Temperature Electrolysis Hydrogen Plant

2010 ◽  
Author(s):  
M. G. McKellar ◽  
E. A. Harvego ◽  
A. M. Gandrik
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Economic Analysis ◽  
Electric Power ◽  
Production Rate ◽  
Production Plant ◽  
System Pressure ◽  
Reference Design ◽  
High Temperature Gas ◽  
High Temperature Electrolysis

An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power for the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

Development Program of IS Process Pilot Test Plant for Hydrogen Production With High-Temperature Gas-Cooled Reactor

2006 ◽  
Author(s):  
Jin Iwatsuki ◽  
Atsuhiko Terada ◽  
Hiroyuki Noguchi ◽  
Yoshiyuki Imai ◽  
Masanori Ijichi ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
High Temperature ◽  
Sulfur Dioxide ◽  
Hydrogen Production ◽  
Co2 Emission ◽  
Test Plant ◽  
Pilot Test ◽  
Fossil Energy ◽  
Bench Scale ◽  
High Temperature Gas

At the present time, we are alarmed by depletion of fossil energy and effects on global environment such as acid rain and global warming, because our lives depend still heavily on fossil energy. So, it is universally recognized that hydrogen is one of the best energy media and its demand will be increased greatly in the near future. In Japan, the Basic Plan for Energy Supply and Demand based on the Basic Law on Energy Policy Making was decided upon by the Cabinet on 6 October, 2003. In the plan, efforts for hydrogen energy utilization were expressed as follows; hydrogen is a clean energy carrier without carbon dioxide (CO2) emission, and commercialization of hydrogen production system using nuclear, solar and biomass, not fossil fuels, is desired. However, it is necessary to develop suitable technology to produce hydrogen without CO2 emission from a view point of global environmental protection, since little hydrogen exists naturally. Hydrogen production from water using nuclear energy, especially the high-temperature gas-cooled reactor (HTGR), is one of the most attractive solutions for the environmental issue, because HTGR hydrogen production by water splitting methods such as a thermochemical iodine-sulfur (IS) process has a high possibility to produce hydrogen effectively and economically. The Japan Atomic Energy Agency (JAEA) has been conducting the HTTR (High-Temperature Engineering Test Reactor) project from the view to establishing technology base on HTGR and also on the IS process. In the IS process, raw material, water, is to be reacted with iodine (I2) and sulfur dioxide (SO2) to produce hydrogen iodide (HI) and sulfuric acid (H2SO4), the so-called Bunsen reaction, which are then decomposed endothermically to produce hydrogen (H2) and oxygen (O2), respectively. Iodine and sulfur dioxide produced in the decomposition reactions can be used again as the reactants in the Bunsen reaction. In JAEA, continuous hydrogen production was demonstrated with the hydrogen production rate of about 30 NL/hr for one week using a bench-scale test apparatus made of glass. Based on the test results and know-how obtained through the bench-scale tests, a pilot test plant that can produce hydrogen of about 30 Nm3/hr is being designed. The test plant will be fabricated with industrial materials such as glass coated steel, SiC ceramics etc, and operated under high pressure condition up to 2 MPa. The test plant will consist of a IS process plant and a helium gas (He) circulation facility (He loop). The He loop can simulate HTTR operation conditions, which consists of a 400 kW-electric heater for He hating, a He circulator and a steam generator working as a He cooler. In parallel to the design study, key components of the IS process such as the sulfuric acid (H2SO4) and the sulfur trioxide (SO3) decomposers working under-high temperature corrosive environments have been designed and test-fabricated to confirm their fabricability. Also, other R&D’s are under way such as corrosion, processing of HIx solutions. This paper describes present status of these activities.

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