High-Temperature Nuclear Energy Technology Based on Sodium-Cooled Fast Reactors for Hydrogen Production

Abstract

Studies show that in principle it is possible by relying on the BN-600 design to secure the required parameters of a reactor setup with a fast reactor with high-temperature sodium coolant (BN-VT) for hydrogen production. The calculations for 600 MW(t) BN-VT for electricity and hydrogen production based on solid-oxide electrolysis of water taking account of a fundamentally different method of purificationremoval of hydrogen and tritium from the sodium by vacuum pumping through special membranes -have shown that the efficiency of such a system is ~40% and hydrogen production volume is 2.8·10 4 liters/sec. The purification of hydrogen by removing tritium to a concentration ensuring the maximum admissible hydrogen concentration in the hydrogen produced 3.26 Bq/liter, imposes additional requirements on the hydrogen removal system.The most important problem determining the future development of environmentally clean power generation is bringing hydrogen into the fuel cycle. Hydrogen is an attractive element for replacing fossil fuels (oil, gas), though it is not a source but rather a carrier of energy. As expected, the demand for hydrogen production is increasing rapidly. At the present time, the main method of hydrogen production is steam conversion of methane. However, from the standpoint of the longterm future of the large-scale production of hydrogen this method is not viable because it requires the use of nonrenewable resources and is accompanied by the release of greenhouse gases. For this reason, alternative methods of hydrogen production by splitting water using thermochemical or electrolytic heat sources are being developed.At present, the best developed high-temperature sources of heat could be Gen-IV nuclear reactors because the proposed heat carriers are gases, liquid metals (sodium, lead) and fused salts. The temperature at the exit from the core in these reactors can reach 900-950°C. They represent a new class of reactors intended for electricity production with high efficiency (50%) and supporting important technological processes in hydrogen production, coal gasification and liquefaction, deep reprocessing of oil, conversion of biomass into liquid fuel as well as in the chemical industry and metallurgy.The conceptual studies performed at the Leipunskii Institute for Physics and Power Engineering (FEI) on the development of a high-energy high-temperature fast sodium reactor (BN-VT) show that the development of such a reactor is technically feasible [1]. The technological problems associated with the high temperature in the reactor setup are paramount. In the present work, a great deal of attention is given to validating the development of a system that secures the quality of the sodium coolant at high temperature and the hydrogen concentration for a long service life, heat-and radiation-resistant hightemperature construction materials and their corrosion resistance with oxygen content in the sodium coolant at the level 0.1 ppm. Concrete estimates were made for 600 MW(t) BN-VT.

Microstructure evolution and constitutive analysis of nuclear grade AISI-316H austenitic stainless steel during thermal deformation

“…AISI-316 austenitic stainless steel (ASS) and its modified versions have garnered widespread adoption in sodium-cooled fast neutron reactors, attributable to the excellent high temperature strength, good plasticity and toughness, high pressure water corrosion resistance, good processing and weldability [1,2]. Compared to standard 316 austenitic stainless steel, 316H contains a higher carbon content, which provides improved oxidation resistance and increased strength at elevated temperatures [3,4].…”