Reunderstand and Discuss the Hardness Limits of RCC-M M5110 Part Materials
Shen Yu-sheng,
Li Fang-zhong,
Ma Wen-sheng,
Zhou Jie,
Zhao Xing-ying,
Yan Li-jun
Issue:
Volume 8, Issue 1, March 2023
Pages:
1-7
Received:
23 February 2023
Accepted:
16 March 2023
Published:
24 March 2023
Abstract: RCC-M M5110 is the procurement code for rolling or forging bars for bolts and drive rods of class 1, 2 and 3 equipment of nuclear power plants. The individual high strength steels involved in this specification specify only the minimum hardness of the material and have no limit on the maximum hardness. The material selection of major components of nuclear power machinery equipment must meet the requirements of load bearing and safe operation, and ensure sufficient strength and hardness, which is especially important for the material selection of connecting bolts and driving rods of nuclear power equipment. As the strength and hardness of high strength steel increase, the plasticity and toughness of materials decrease sharply, as do the mechanical properties and corrosion resistance, increasing the risk of bolt fracture and equipment damage. In order to ensure the strength and hardness of metal materials, it is necessary to consider the comprehensive mechanical properties and corrosion resistance of the material, including resistance stress corrosion cracking (SCC). Improving strength and hardness should not be the only goal of improving the performance of metal materials. In the formulation and selection of raw material standards, the mechanical properties of important equipment materials, such as hardness, must be limited. To meet the requirements of "redundant design" and "defense in depth" of nuclear power equipment. This paper will discuss how to reunderstand the the hardness limits of RCC-M M 5110 materials.
Abstract: RCC-M M5110 is the procurement code for rolling or forging bars for bolts and drive rods of class 1, 2 and 3 equipment of nuclear power plants. The individual high strength steels involved in this specification specify only the minimum hardness of the material and have no limit on the maximum hardness. The material selection of major components of ...
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Evaluation of the Basic Neutronics and Thermal-Hydraulics for the Safety Evaluation of the Advanced Micro Reactor (AMR)
Wayne Arthur Boyes,
Johan Slabber,
Charl du Toit,
Francois van Heerden
Issue:
Volume 8, Issue 1, March 2023
Pages:
8-29
Received:
28 March 2023
Accepted:
27 April 2023
Published:
10 May 2023
Abstract: South Africa requires safe affordable distributed base load energy, one way to achieve this is to use nuclear power integrated with renewable energy sources on a decentralized basis. This suggests the development of its own micro modular nuclear reactor, to supply energy to towns, small communities, mines and processing plants. Large Light Water Reactors (LWRs) are expensive and require a large infrastructure development. A High Temperature Reactor (HTR) called the Advanced Micro Reactor (AMR) is in the process of being developed and the design philosophy is to design for inherent safety, maximally using technology that has been developed and validated in previous HTR programs albeit in a completely different and unique configuration. The concept is based on existing knowhow and experience/expertise in South Africa during the time of the Pebble Bed Modular reactor (PBMR) project. These AMR reactors are to be factory built to obtain good quality control and rolled out to various sites. Once the reactor has reached its end of life, it would be returned to a licensed organisation for refuelling. The AMR produces 10MW of thermal power. The reactor configuration uses hexagonal graphite blocks for structural and moderator material, which are arranged to form a cylindrical core layout. The fuel assemblies are silicon carbide tubes that house coated particle fuel, immersed in a lead-bismuth eutectic alloy (LBE). Each fuel assembly is contained in a boring within the graphite moderator that allows an annulus for cooling. There are 420 fuel assemblies in the core. Low enriched fuel in the form of UO2 or UCO is used. Helium gas is used as coolant. The coolant enters the core at 450°C and exits at 750°C. The mechanical, neutronic and thermal-hydraulic design of the AMR, is being evaluated with assistance from STL Nuclear (Pty) Ltd., the University of Pretoria (UP), the North-West University and the South African Nuclear Energy Corporation (NECSA). The OSCAR-5 code package, together with the Serpent neutronic code were used to perform the basic neutronic studies while the Flownex package was used to determine the thermal-hydraulic and safety evaluation for the Design Base Accident (DBA) specifically the Depressurized Loss of Forced Cooling (DLOFC) event.
Abstract: South Africa requires safe affordable distributed base load energy, one way to achieve this is to use nuclear power integrated with renewable energy sources on a decentralized basis. This suggests the development of its own micro modular nuclear reactor, to supply energy to towns, small communities, mines and processing plants. Large Light Water Re...
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