Effect of offset distance on the performance of two-region porous inert medium burners at low thermal power operation

2018 ◽

Vol 4 (2) ◽

Author(s):

Xie Yang ◽

Ding She ◽

Lei Shi

Keyword(s):

Nuclear Reactor ◽

High Efficiency ◽

Nuclear Reactors ◽

Thermal Power ◽

Safety Margin ◽

Outlet Temperature ◽

Full Power ◽

Power Operation ◽

Uranium Nitride ◽

Enriched Uranium

Due to the advantages of small volume, light weight, and long-time running, nuclear reactor can provide an ideal energy source for space crafts. In this paper, two small compact prismatic nuclear reactors with different core block materials are presented, which have a thermal power of 5 MW for 10 years of equivalent full power operation. These two reactors use Mo-14%Re alloy or nuclear grade graphite IG110 as core block material, loaded with 50% and 39.5% enriched uranium nitride (UN) fuel and cooled by helium, whose inlet/outlet temperature of the reactor and operational pressure are 850/1300 K and 2 MPa, respectively. High temperature helium flowing out of the reactor can be used as the working medium for closed Brayton cycle power conversion with high efficiency (more than 20%). Neutronics analyses of reactors for the preliminary design in this paper are performed using reactor Monte Carlo (RMC) code developed by Tsinghua University. Both the reactors have enough initial excess reactivity to ensure 10 years of full power operation without refueling, have safety margin for reactor shutdown with one control drum failed, and remain subcritical in the submersion accident. Finally, the two reactors are compared in aspect of the 235U mass and the total reactor mass.

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Neutronics Analyses of Small Compact Prismatic Nuclear Reactors for the Preliminary Design

Volume 5: Advanced and Next Generation Reactors, Fusion Technology; Codes, Standards, Conformity Assessment, Licensing, and Regulatory Issues ◽

10.1115/icone25-66290 ◽

2017 ◽

Author(s):

Xie Yang ◽

Lei Shi ◽

Ding She

Keyword(s):

Optimization Design ◽

Nuclear Reactor ◽

High Efficiency ◽

Nuclear Reactors ◽

Thermal Power ◽

Outlet Temperature ◽

Preliminary Design ◽

Full Power ◽

Power Operation ◽

Enriched Uranium

Due to the advantages of small volume, light weight and long-time running, nuclear reactor can provide an idea energy source for submarines, ships and even space crafts. In this paper, two small compact prismatic nuclear reactors with different core block material are presented, which have a thermal power of 5 MW for 10 years of equivalent full power operation. These two reactors use Mo-14%Re alloy or nuclear grade graphite IG110 as core block material, loaded with high enriched uranium nitride fuel and cooled by helium, whose inlet/outlet temperature of the reactor and operational pressure are 850/1300 K and 2 MPa respectively. High temperature helium flowing out of the reactor can be used as the working medium for Closed Brayton Cycle (CBC) power conversion to generate at least 1 MW electricity due to the high efficiency of CBC. Neutronics analyses of reactors for the preliminary design in this paper are performed using Reactor Monte-Carlo (RMC) code developed by Tsinghua University. Both the two reactors have enough initial excess reactivity to ensure 10 years of full power operation without refueling, which have at least $1 reactivity shutdown margin, and remains at least $1 subcritical in the submersion accident as well as one control drum failed accident. Finally, the optimization design is determined after comparing the U-235 mass and the total reactor mass of the above two prismatic reactors.

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A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset196270 ◽

2018 ◽

pp. 413-418

Author(s):

Harshkumar Patel ◽

Yogesh Patel

Keyword(s):

Fly Ash ◽

Electricity Generation ◽

Power Plants ◽

Renewable Energy Sources ◽

Thermal Power ◽

Strength Test ◽

Partial Replacement ◽

Pond Ash ◽

Research Activities ◽

Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

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