Gascooled, graphitemoderated veryhightemperature reactors vhtrs are one design concept of generation vi reactors. Pdf conceptual design of a very high temperature pebblebed. Consequently, a detailed design of a fluidized bed reactor that would allow flexible operation at high temperature and high pressure at several gas velocities will be conducted in order to serve for the future development of new hydrodynamic models. The very hightemperature reactor vhtr design descriptions, technology.
The very high temperature reactor vhtr design descriptions, technology overviews, and discussions of issues, concerns, and benefits documented in this report establish the bases to support more detailed assessments, as the designs evolve, using the methodology developed for evaluating the. To do this, we focused on the plant design described in section 2, which is similar to the gtmhr plant design 850c core outlet temperature. These temperatures are at the very limits of practical engineering materials. Conceptual design of a very high temperature pebblebed reactor. The reactor core can be either a prismatic block or a pebblebed core. The veryhightemperature reactor, or hightemperature gascooled reactor, is a generation iv reactor concept that uses a graphitemoderated nuclear reactor with a oncethrough uranium fuel cycle. Hightemperature gascooled reactor htgr nrc research plan.
S department of energy doe is conducting research on the very high temperature reactor vhtr design concept for the next generation nuclear plant ngnp project. It is a graphitemoderated, heliumcooled reactor with thermal neutron spectrum. The vhtr is a type of hightemperature reactor htr that can conceptually have an outlet temperature of c. High temperature gas reactornew production reactor. The mhtgr design approach leading to exceptional safety performance also leads to plant operation which is characterized by extremely low radiological emissions even for very low probability accidents. The very high temperature reactor is a generation iv reactor concept that uses a graphite moderated nuclear reactor with a once through uranium fuel cycle. Modular high temperature gas reactor russia general atomics design 290 mwe prismatic core excess weapons plutonium burner in design phase in russia direct cycle start of construction depends on us gov funding maybe never. Pincock april 2011 idaho national laboratory next generation nuclear plant project idaho falls, idaho 83415 prepared for the u. One design may have low reactor cost, but the materials leaving the unit may be such that their treatment requires a much higher cost than alternative designs. It is a type of very high temperature reactor vhtr, one of the six classes of nuclear reactors in the generation iv initiative.
The high graphite inventory provides significant thermal inertia. Very high temperature reactor vhtr safety assessment white paper 3 successful development of components, graphite, plant design etc. Reactors require much attention to safety details in the design process due to the hazards they impose. An application in the late stages of design maturity to measure the level of safety and risk associated with a given design relative to safety objectives or licensing criteria. To minimize thermal stress in hightemperature components, the temperature was raised within the rate of 35ch when the outlet coolant temperature is less than below 650c and 15ch when the coolant temperature is above 650c. Overview of technology the very high temperature reactor vhtr is a heliumcooled, triso coated particle fuel. The term very high temperature reactor vhtr is often applied to htgr designs with outlet temperatures above 800oc. The high temperature gascooled reactor jrc publications. The ngnp reactor core will be either a prismatic graphite block type. He is currently a program manager for advanced reactor deployment within the. Reactor design lectures notes university of technology, iraq. Manual or computer automated image analysis is performed to measure the minimum. The vessels utilize thrust bolts and a thrust ring to ensure positive seating of the gasket.
Moltensaltcooled advanced hightemperature reactor for. Modeling of the thermal hydraulics of veryhightemperature. The construction began in december 2012 and the operation is expected in 2017. Volume stability, expansion, and shrinkage at high temperatures. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner.
Neutronic design of a very high temperature reactor core with. Types nuclear reactor design advantages and disadvantages of. Parametric studies were performed to determine core characteristics required to achieve a target core cycle length of 18 months and fuel discharge. Technology assessments introduction high temperature reactor htr systems i. High temperature gascooled reactors lessons learned applicable to the next generation nuclear plant j. The steam generator, the reactor and the blowers are all in the same reactor pressure vessel. More recently, two additional htgr test reactors have been constructed and are successfully being operated, the 30 mwt high temperature test reactor httr in japan and the 10 mwt high temperature reactor htr10 in china table 1, with design outlet temperatures of. Generation iv reactors integrated materials technology. Taiwo nuclear engineering division, argonne national laboratory march 31, 2006. It can supply nuclear heat and electricity over a range of core outlet temperatures between 700 and 950c, or more than 1 000c in future. A small modular nuclear reactor to replace coal plants could be on the market within 5 years. The contraction or expansion of the refractories can take place during service life. They are often the highest temperature point in the process, heat of reaction may be released, and residence times can be. Draft preapplication safety evaluation report for the modular hightemperature gascooled reactor nureg38 was written in early 1989.
It is a type of veryhightemperature reactor vhtr, one of the six classes of nuclear reactors in the generation iv initiative. In any manufacturing process where there is a chemical change. The purpose of this report is to identify the materials research and development needs for the vhtr. High temperature gas reactors idaho national laboratory. China could have a meltdownproof nuclear reactor next year.
Neutronic design of a very high temperature reactor core. In addition the operation of these reactors at high temperature for many years could lead to degradation of the graphite material properties. Design of the reactor is no routine matter, and many alternatives can be proposed for a process. Seven high temperature gascooled reactors have been built, but only two units remain in operation, both relatively small. Chapter 4 the high temperature gas cooled reactor test module. Very high temperature reactor vhtr among the 6 candidates of the gen iv nuclear systems in the technical roadmap of gen iv international forum gif, the very high temperature reactor vhtr is primarily dedicated to the cogeneration of electricity and hydrogen, the latter being extracted from water by using thermochemical, electrochemical or hybrid processes. The reactor core can be either a prismatic block reminiscent of a. In addition, this report includes updated information on codes and standards for high temperature gas cooled reactors htgrs at the time of.
A pebble bedtype of veryhigh temperature gascooled reactor vhtr is one of the most probable solutions goodjohn, 1991 and the most promising concept koster et al. Veryhightemperature reactor presented by taher, md iktiham bin 15983781 khan, md rabiul islam 15982791 islam, kazi rashedul 15984751 2. In searching for the optimum it is not just the cost of the reactor that must be minimized. The moltensaltcooled advanced hightemperature reactor ahtr is a new reactor concept designed to provide very high temperature 750 to ec heat to enable efficient lowcost 1 thermochemical production of hydrogen h2 or 2 production of electricity. The vhtr is a next step in the evolutionary development of hightemperature gascooled reactors. The basic design of pebblebed reactors features spherical fuel elements called pebbles. This reactor design envisions an outlet temperature of c. Seven hightemperature gascooled reactors have been built, but only two units remain in operation, both relatively small. High pressure equipment pressure vessels and reactors.
Very hightemperature reactor vhtr proliferation resistance. Department of energy office of nuclear energy under doe idaho operations office. In the mid1980s, doe turned to a smaller modular design a modular htgr with an annular core and steel rpv, and a conceptual design was completed in 1987. Aug 01, 2008 generation iv reactors integrated materials technology program plan. The reactor power was kept at 50 % 15 mw th, 67% 20 mw th, and 100% 30 mw th. The status of hightemperature gascooled reactor development and design in the united states and other countries important benefits are foreseen from smaller, modular systems by l. The pebblebed reactor pbr is a design for a graphitemoderated, gascooled nuclear reactor. Focus on very high temperature reactor materials showing 14 of 111 pages in this report. Reactors, which operate at very high temperatures, such as the high temperature gas reactor or various fluoride cooled high temperature reactors could improve economic feasibility through diversification.
Creep is a time dependent property, which determines the deformation in a given time and at a given temperature by a refractory material under stress. Graphite also has a high thermal conductivity, which facilitates the transfer of heat to the reflector, and it can withstand high temperatures. A new reactor concept, the advanced hightemperature reactor ahtr, is being developed. Basic objectives in design of a reactor in chemical engineering physical operations such as fluid flow, heat transfer, mass transfer and separation processes play a very large part. This paper provides an initial description and technical analysis of its key features. Some of the issues are common to both the prism and pebble bed designs, others are specific to the type of reactor. In the usa, the 150 mwe gas turbine modular helium reactor gtmhr is a conceptual design that has the potential to produce hydrogen by high temperature electrolysis or thermochemical water splitting. Sagr super critical water reactor, scwr advanced light water reactors, alwr advanced high temperature reactor, ahtr lead bismuth cooled reactor, hmcr t outlet c 850950 650750 400600 285320 750 540570 rl% 4548 475 1 3845 3234 ne ne. Gascooled reactors have had a long and varied history dating back to the very early days of nuclear energy development. A third vhtr mission actinide burning can be accomplished with either the hydrogenproduction or gas turbine designs.
Group 10s presentation for nre 2110 on the very high temperature reactor design. For all irreversible reactions of greater than zero order, the volume of the reactor approaches. Series gc is designed for studying high temperature and pressure reactions. In 2014, the generation iv international forum confirmed the very high temperature reactor vhtr as one of 6 promising reactor technologies that should be pursued in order to develop advanced reactors suitable for deployment in the 2030s. Veryhightemperature reactor vhtr among the 6 candidates of the gen iv nuclear systems in the technical roadmap of gen iv international forum gif, the very high temperature reactor vhtr is primarily dedicated to the cogeneration of electricity and hydrogen, the latter being extracted from water by using thermochemical, electrochemical or hybrid processes. The term very high temperature reactor vhtr loosely covers any reactor design with a coolant outlet temperature of c or above. Gascooled, graphitemoderated very high temperature reactors vhtrs are one design concept of generation vi reactors.
Pdf conceptual design of a very high temperature pebble. The very high temperature reactor the term very high temperature reactor vhtr loosely covers any reactor design with a coolant outlet temperature of c or above. Pdf design options for the advanced hightemperature reactor. No radial variation in reaction rate concentration and the reactor is. Survey of sodiumcooled fast reactor fuel handling systems for relevant design and operating characteristics anlgeniv069 by j. Thermal hydraulics of the very high temperature gas cooled. The vhtr is a type of hightemperature reactor that can conceptually have an outlet temperature of c. For asme code stamping of hip vessels, please consult factory for available reactor designs, materials, and pressure ratings. The outlet temperature similar to core exit temperature in a lightwater reactor of an htgr can vary from as low as 650 oc to 950 c or above. China could have a meltdownproof nuclear reactor next. High temperature gascooled reactors lessons learned.
Advanced reactor technology helium gas cooled reactor, gtmhr supercritical co, cycle with i. This plant design utilizes basic high temperature gascooled reactor htgr features of ceramic fuel, helium coolant, and a graphite moderator. In particular this report addresses the comments provided by inl and documented in 1463 rev. To examine the ability of the thermal hydraulics system code athlet for the safety assessment of these reactors, we performed simulations of the cores of both pebble bed and prismatic block vhtrs. The design of the htr graphite cores must account for these thermal, irradiation conditions. These tennis ballsized pebbles are made of pyrolytic graphite which acts as the. A pebble bedtype of very high temperature gascooled reactor vhtr is one of the most probable solutions goodjohn, 1991 and the most promising concept koster et al. High temperature gas reactors an overview sciencedirect.
Hightemperature gascooled reactor htgr nrc research. The advanced high temperature reactor the primary challenge for nuclear h2 production is the requirement to deliver heat to the thermochemical plant at very high temperatures. Draft preapplication safety evaluation report for the modular high temperature gascooled reactor nureg38 was written in early 1989. The term typically refers to the next step in the evolutionary development of hightemperature gascooled reactors htgrs.
Key design parameters of the htr10 41 reactor thermal power mw 10 primary helium pressure mpa 3. The veryhightemperature reactor vhtr, or hightemperature gascooled reactor htgr, is a generation iv reactor concept that uses a graphitemoderated nuclear reactor with a oncethrough uranium fuel cycle. Design codes and standards manufacturing methodologies improved multiscale modelling to support inelastic fem analyses hightemperature heat exchangers and steam generators 3 material categories and corresponding wg. Futterer eu on behalf of the gif vhtr system steering committee michael. The advanced hightemperature reactor ahtr for producing. However, there was no urgent or strong commercial demand, although the essential needs. The very high volumetric heat capacity of the coolant and its other properties enable the development of compact modular reactors 100 mwt as well as high power reactors 20004000 mw. Advantages of very high temperature reactors clear passive safety mechanism 1. They are often the highest temperature point in the process, heat of reaction may be released, and residence times can be long leading to a large inventory of chemicals. Generation iv reactors integrated materials technology program plan. Very high temperature reactor vhtr inl digital library.