Icone11-36222 the Future of Nuclear : SCWR Generation Iv High Performance Channels

Duffey, Romney B.; Khartabil, Hussam F.; Pioro, Igor; Hopwood, J. M.

doi:10.1299/jsmeicone.2003.154

Cited by 8 publications

(8 citation statements)

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“…Safety and other systems seem to be similar to those implemented in modern nuclear reactors. High pressures and temperatures inside the reactor core require a new design of the fuel channel (7) . Current CANDU reactors use a channel design that consists of a pressure channel that is insulated from the cool heavy-water moderator by an annulus gap filled with inert gas and a calandria tube (see Fig.…”

Section: Canadian Scwr Conceptmentioning

confidence: 99%

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SCW Pressure-Channel Nuclear Reactor Some Design Features

Pioro

Khan

Hopps

et al. 2008

JPES

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Concepts of nuclear reactors cooled with water at supercritical pressures were studied as early as the 1950s and 1960s in the USA and Russia. After a 30-year break, the idea of developing nuclear reactors cooled with SuperCritical Water (SCW) became attractive again as the ultimate development path for water cooling. The main objectives of using SCW in nuclear reactors are: 1) to increase the thermal efficiency of modern Nuclear Power Plants (NPPs) from 30 -35% to about 45 -48%, and 2) to decrease capital and operational costs and hence decrease electrical energy costs (~$1000 US/kW or even less). SCW NPPs will have much higher operating parameters compared to modern NPPs (pressure about 25 MPa and outlet temperature up to 625ºC), and a simplified flow circuit, in which steam generators, steam dryers, steam separators, etc., can be eliminated. Also, higher SCW temperatures allow direct thermo-chemical production of hydrogen at low cost, due to increased reaction rates. Pressure-tube or pressure-channel SCW nuclear reactor concepts are being developed in Canada and Russia for some time. Some design features of the Canadian concept related to fuel channels are discussed in this paper. The main conclusion is that the development of SCW pressure-tube nuclear reactors is feasible and significant benefits can be expected over other thermal-energy systems.

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Section: Canadian Scwr Conceptmentioning

confidence: 99%

“…In general, water-cooled nuclear reactors operating at subcritical pressures (7)(8)(9)(10)(11)(12)(13)(14)(15)(16) started to be developed at the end of 1940s and have been used for the last fifty years. At the same time, i.e., as early as the 1950s, concepts of SCWRs were studied in the USA and Russia.…”

Section: Introductionmentioning

confidence: 99%

SCW Pressure-Channel Nuclear Reactor Some Design Features

Pioro

Khan

Hopps

et al. 2008

JPES

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“…The SCWR concepts fall into two main types: (a) a large reactor pressure vessel (PV) (14) with a wall thickness of about 0.5 m, analogous to conventional Light Water Reactors (LWRs), or (b) distributed pressure tubes (PT) or channels evolving from conventional Heavy Water Reactors (HWRs) (7) (16)- (20) .…”

Section: Design Considerations Of Scwrsmentioning

confidence: 99%

“…High pressures and temperatures inside the reactor core require a new fuel-channel design (20) . Current CANDU reactors use a channel design that consists of a pressure channel that is insulated from the cool heavy-water moderator by an annulus gap filled with inert gas and a calandria tube (10) .…”

Section: Canadian Scwr Conceptmentioning

confidence: 99%

Advanced Concepts for Pressure-Channel Reactors: Modularity, Performance and Safety

Duffey

Pioro

Kuran³

2008

JPES

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Based on an analysis of the development of advanced concepts for pressure-tube reactor technology, we adapt and adopt the pressure-tube reactor advantage of modularity, so that the subdivided core has the potential for optimization of the core, safety, fuel cycle and thermal performance independently, while retaining passive safety features. In addition, by adopting supercritical water-cooling, the logical developments from existing supercritical turbine technology and "steam" systems can be utilized. Supercritical and ultra-supercritical boilers and turbines have been operating for some time in coal-fired power plants. Using coolant outlet temperatures of about 625ºC achieves operating plant thermal efficiencies in the order of 45-48%, using a direct turbine cycle. In addition, by using reheat channels, the plant has the potential to produce low-cost process heat, in amounts that are customer and market dependent. The use of reheat systems further increases the overall thermal efficiency to 55% and beyond. With the flexibility of a range of plant sizes suitable for both small (400 MW e) and large (1400 MW e) electric grids, and the ability for co-generation of electric power, process heat, and hydrogen, the concept is competitive. The choice of core power, reheat channel number and exit temperature are all set by customer and materials requirements. The pressure channel is a key technology that is needed to make use of supercritical water (SCW) in CANDU ®1 reactors feasible. By optimizing the fuel bundle and fuel channel, convection and conduction assure heat removal using passive-moderator cooling. Potential for severe core damage can be almost eliminated, even without the necessity of activating the emergency-cooling systems. The small size of containment structure lends itself to a small footprint, impacts economics and building techniques. Design features related to Canadian concepts are discussed in this paper. The main conclusion is that development of SCW pressure-channel nuclear reactors is feasible and significant benefits can be expected over other thermal-energy systems.

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“…In the last few years, conceptual design work on channel reactors with light water at pressure 25 MPA and temperature 400-625°C at the reactor exit has been conducted in Canada using the CANDU reactor as a basis [4][5][6]. An evolutionary development is proposed for the improved CANDU reactor (ACR), once again oriented toward a cost-effective neutron balance, i.e., a heavy-water moderator and slightly enriched dioxide fuel.…”

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confidence: 99%

Direct-Flow Channel Reactor with Supercritical Coolant Pressure

et al. 2005

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The concept of a direct-flow channel reactor with supercritical-pressure water (CR-SCP) is presented. Neutron-physics, thermohydraulic, and strength calculations are used to substantiate the fundamental core design with a heavy-metal moderator which at supercritical pressure is competitive with other modern reactor designs with respect to fuel-cycle indicators. Two types of fuel-element and fuel-channel structures are examined. It is shown that fuel elements based on micropellets and a metal matrix are highly reliable and have higher operating characteristics (burnup, service life, geometric stability, and so on) than fuel elements with uranium-dioxide fuel. A CR-SCP design and the technological scheme of a power-generating unit are presented, and the systems which are required to ensure normal operation and safety are determined. The main technical-economic indicators of a power-generating unit with installed electric power 850 MW are estimated.The interest in supercritical coolant pressure in reactors is due to the fact the new reactors must be competitive. In the last few years a surge of interest has been observed in Japan, USA, Germany, France, Canada, and other countries [1]. Reactors with supercritical-pressure water are being considered as one direction in the international program for the development of fourth-generation reactors.Some countries are undertaking efforts to develop direct-flow water-moderated water-cooled vessel reactors with supercritical-coolant pressure. The core of these reactors can be designed to operate on thermal and fast neutrons with almost the same thermal layouts of the power-generating units and the same efficiency. It is important to note that a fast-neutron reactor makes it possible, aside from appreciably decreasing the capital costs, to improve fuel utilization [2], since it makes it possible to increase the breeding ratio of nuclear fuel up to 1 and aim at a closed fuel cycle. However, such reactors are characterized by a change in water density by a factor of 10 from the core entrance to the core exit. This is accompanied by a change in the neutron spectrum over the height of the core and makes it difficult to smooth and stabilize the energy-release fields not only

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Icone11-36222 the Future of Nuclear : SCWR Generation Iv High Performance Channels

Cited by 8 publications

References 0 publications

SCW Pressure-Channel Nuclear Reactor Some Design Features

SCW Pressure-Channel Nuclear Reactor Some Design Features

Advanced Concepts for Pressure-Channel Reactors: Modularity, Performance and Safety

Direct-Flow Channel Reactor with Supercritical Coolant Pressure

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