Supercritical water reactor(SCWR) was proposed as a GenerationⅣconcept for building large capacity nuclear power plants.Comparing with the present GenerationⅡandⅢlight water reactors,SCWR possesses great advantages...Supercritical water reactor(SCWR) was proposed as a GenerationⅣconcept for building large capacity nuclear power plants.Comparing with the present GenerationⅡandⅢlight water reactors,SCWR possesses great advantages of 10%higher efficiency,simpler system design,better sustainability,and so on. However,the selection of materials for fuel cladding and reactor internals of SCWR is facing a great challenge. Corrosion in supercritical steam is of the first important issue to be solved to meet the stringent requirement of the reactor internal components.Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor(SCWR) in static and re-circulating autoclave at the temperatures of 550,600 and 650℃,pressure of about 25 MPa,deaerated or saturated dissolved hydrogen(STP). Nickel base alloy type Hastelloy C276,austenitic stainless steels type 304NG,AL-6XN,HR3C.NF709 and SAVE 25,ferritic/martensitic(F/M) steel type P92,P122 and 410,and oxide dispersion strengthened steel MA 956,are tested.This paper presents corrosion rate,and focuses on the formation and breakdown of corrosion oxide film,and proposes the future trend for the development of SCWR internal structure materials.展开更多
The purpose of the study is to analyze the breeding ratio of a supercritical water cooled fast reactor (SCFR) and to increase the breeding core of SCFR. The sensitivities of assembly parameters, core arrangements and ...The purpose of the study is to analyze the breeding ratio of a supercritical water cooled fast reactor (SCFR) and to increase the breeding core of SCFR. The sensitivities of assembly parameters, core arrangements and fuel nuclide components to the breeding ratio are analyzed. In assembly parameters, the seed fuel rod diameter has higher sensitivities to the conversion ratio (CR) than the coolant tube diameter in blanket. Increasing heavy metal fraction is good to CR improvement. The CR of SCFR also increases with a reasonable core arrangement and Pu isotope mass fraction reduction in fuel, which can achieve more negative coolant void reactivity coefficient at the same time. The breeding ratio of SCFR is 1.03128 with a new core arrangement. And the coolant void reactivity coefficient is negative, which achieves a fuel breeding in initial fuel cycle.展开更多
Research into flow instability at both subcritical and supercritical pressures has attracted attention in recent years because of its potential of occurrence in industrial heat transfer systems. Flow instability has t...Research into flow instability at both subcritical and supercritical pressures has attracted attention in recent years because of its potential of occurrence in industrial heat transfer systems. Flow instability has the potential to affect the safety of design and operation of heat transfer equipment. Flow instability is therefore undesirable and should be avoided?in the design and operation of industrial equipment. Rahman?et al. reviewed studies on supercritical water heat transfer with the aim of providing references for SCWR researchers. It was found out that most of the CFD studies and experimental studies were performed with single tube geometry due to the complexity of parallel channel geometry. Because studies performed with parallel channel geometry could provide detailed information to the design of the SCWR core, they called for more studies in parallel channel geometry at supercritical pressures in the future. In order to help understand how flow instability investigations are carried out and also highlight the need to understand flow instability phenomenon and equip the designers and operators of industrial heat transfer equipment with the needed knowledge on flow instability, this study carried out a review of flow instability in parallel channels with water at supercritical pressures.展开更多
基于带定位格架类三角形子通道超临界水流动传热试验,数值研究了棒径为8 mm,栅距比为1.4的超临界水冷堆(Supercritical Water Cooled Reactor,SCWR)类三角形通道超临界流动传热定位格架结构影响,分析了同型定位格架典型结构参数和不同...基于带定位格架类三角形子通道超临界水流动传热试验,数值研究了棒径为8 mm,栅距比为1.4的超临界水冷堆(Supercritical Water Cooled Reactor,SCWR)类三角形通道超临界流动传热定位格架结构影响,分析了同型定位格架典型结构参数和不同定位格架型式对堆芯通道超临界流动传热特性的影响规律。研究结果表明:定位格架可强化堆芯通道超临界水传热,同型格架本体厚度越大,压力损失越高,格架处壁面温度越低,局部换热能力越好,当增大格架本体厚度,弱化程度无明显差异;阻流片型定位格架下游局部换热能力提高显著,阻流片直径越大,上游压力越大,局部壁温越低,换热系数越高,增大阻流片直径可减小传热弱化区域大小,强化传热能力;不同定位格架型式对比研究发现交错叶片型弱化区域最大,阻流片型定位格架弱化区域最小,阻流片型定位格架具有最佳的传热强化效果。展开更多
Research activities involving heat transfer at supercritical pressures have attracted attention in recent years because of possibility of increase in thermal output of heat transfer and industrial equipment. Because o...Research activities involving heat transfer at supercritical pressures have attracted attention in recent years because of possibility of increase in thermal output of heat transfer and industrial equipment. Because of high pressure and temperature conditions associated with heat transfer at supercritical pressures, only few experimental heat transfer studies are being carried out at supercritical conditions. The use of numerical tools for heat transfer and other related studies at supercritical pressures is increasing because of the high-pressure-temperature limitation of experimental studies at supercritical conditions. Heat transfer correlations implemented in these numerical tools are used to obtain numerical heat transfer data to complement experimental heat transfer data provided through experimental studies. In order to further broaden the understanding of fluid flow and heat transfer, this review examines the performance of heat transfer correlations adopted at supercritical pressures. It is found from the review that most of the correlations could predict heat transfer quite well in the low enthalpy region and few of the correlations could predict heat transfer in the high enthalpy region near critical and pseudo-critical conditions (heat transfer deteriorated conditions). However, no single heat transfer correlation is able to accurately predict all the experimental results presented in this work.展开更多
The ambitious nuclear power program motivates the Chinese nuclear community to develop advanced reactor concepts of generation IV,in order to ensure the long-term,stable and sustainable development of nuclear power.Th...The ambitious nuclear power program motivates the Chinese nuclear community to develop advanced reactor concepts of generation IV,in order to ensure the long-term,stable and sustainable development of nuclear power.The supercritical water-cooled reactor(SCWR)has favorable features in economics,sustainability and technology availability.It is the logical extension of the existing PWR technology and has very promising perspectives in large-scale power generation in China.This paper describes the main features of SCWR.New designs of SCWR core structure and fuel assemblies are proposed.Preliminary analysis using a coupled neutron-physics/thermal-hydraulics method is carried out and shows a good feasibility of the new design proposal.展开更多
文摘Supercritical water reactor(SCWR) was proposed as a GenerationⅣconcept for building large capacity nuclear power plants.Comparing with the present GenerationⅡandⅢlight water reactors,SCWR possesses great advantages of 10%higher efficiency,simpler system design,better sustainability,and so on. However,the selection of materials for fuel cladding and reactor internals of SCWR is facing a great challenge. Corrosion in supercritical steam is of the first important issue to be solved to meet the stringent requirement of the reactor internal components.Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor(SCWR) in static and re-circulating autoclave at the temperatures of 550,600 and 650℃,pressure of about 25 MPa,deaerated or saturated dissolved hydrogen(STP). Nickel base alloy type Hastelloy C276,austenitic stainless steels type 304NG,AL-6XN,HR3C.NF709 and SAVE 25,ferritic/martensitic(F/M) steel type P92,P122 and 410,and oxide dispersion strengthened steel MA 956,are tested.This paper presents corrosion rate,and focuses on the formation and breakdown of corrosion oxide film,and proposes the future trend for the development of SCWR internal structure materials.
文摘The purpose of the study is to analyze the breeding ratio of a supercritical water cooled fast reactor (SCFR) and to increase the breeding core of SCFR. The sensitivities of assembly parameters, core arrangements and fuel nuclide components to the breeding ratio are analyzed. In assembly parameters, the seed fuel rod diameter has higher sensitivities to the conversion ratio (CR) than the coolant tube diameter in blanket. Increasing heavy metal fraction is good to CR improvement. The CR of SCFR also increases with a reasonable core arrangement and Pu isotope mass fraction reduction in fuel, which can achieve more negative coolant void reactivity coefficient at the same time. The breeding ratio of SCFR is 1.03128 with a new core arrangement. And the coolant void reactivity coefficient is negative, which achieves a fuel breeding in initial fuel cycle.
文摘Research into flow instability at both subcritical and supercritical pressures has attracted attention in recent years because of its potential of occurrence in industrial heat transfer systems. Flow instability has the potential to affect the safety of design and operation of heat transfer equipment. Flow instability is therefore undesirable and should be avoided?in the design and operation of industrial equipment. Rahman?et al. reviewed studies on supercritical water heat transfer with the aim of providing references for SCWR researchers. It was found out that most of the CFD studies and experimental studies were performed with single tube geometry due to the complexity of parallel channel geometry. Because studies performed with parallel channel geometry could provide detailed information to the design of the SCWR core, they called for more studies in parallel channel geometry at supercritical pressures in the future. In order to help understand how flow instability investigations are carried out and also highlight the need to understand flow instability phenomenon and equip the designers and operators of industrial heat transfer equipment with the needed knowledge on flow instability, this study carried out a review of flow instability in parallel channels with water at supercritical pressures.
文摘基于带定位格架类三角形子通道超临界水流动传热试验,数值研究了棒径为8 mm,栅距比为1.4的超临界水冷堆(Supercritical Water Cooled Reactor,SCWR)类三角形通道超临界流动传热定位格架结构影响,分析了同型定位格架典型结构参数和不同定位格架型式对堆芯通道超临界流动传热特性的影响规律。研究结果表明:定位格架可强化堆芯通道超临界水传热,同型格架本体厚度越大,压力损失越高,格架处壁面温度越低,局部换热能力越好,当增大格架本体厚度,弱化程度无明显差异;阻流片型定位格架下游局部换热能力提高显著,阻流片直径越大,上游压力越大,局部壁温越低,换热系数越高,增大阻流片直径可减小传热弱化区域大小,强化传热能力;不同定位格架型式对比研究发现交错叶片型弱化区域最大,阻流片型定位格架弱化区域最小,阻流片型定位格架具有最佳的传热强化效果。
文摘Research activities involving heat transfer at supercritical pressures have attracted attention in recent years because of possibility of increase in thermal output of heat transfer and industrial equipment. Because of high pressure and temperature conditions associated with heat transfer at supercritical pressures, only few experimental heat transfer studies are being carried out at supercritical conditions. The use of numerical tools for heat transfer and other related studies at supercritical pressures is increasing because of the high-pressure-temperature limitation of experimental studies at supercritical conditions. Heat transfer correlations implemented in these numerical tools are used to obtain numerical heat transfer data to complement experimental heat transfer data provided through experimental studies. In order to further broaden the understanding of fluid flow and heat transfer, this review examines the performance of heat transfer correlations adopted at supercritical pressures. It is found from the review that most of the correlations could predict heat transfer quite well in the low enthalpy region and few of the correlations could predict heat transfer in the high enthalpy region near critical and pseudo-critical conditions (heat transfer deteriorated conditions). However, no single heat transfer correlation is able to accurately predict all the experimental results presented in this work.
文摘The ambitious nuclear power program motivates the Chinese nuclear community to develop advanced reactor concepts of generation IV,in order to ensure the long-term,stable and sustainable development of nuclear power.The supercritical water-cooled reactor(SCWR)has favorable features in economics,sustainability and technology availability.It is the logical extension of the existing PWR technology and has very promising perspectives in large-scale power generation in China.This paper describes the main features of SCWR.New designs of SCWR core structure and fuel assemblies are proposed.Preliminary analysis using a coupled neutron-physics/thermal-hydraulics method is carried out and shows a good feasibility of the new design proposal.
