Development of cladding materials for sodium-cooled fast reactors in India

Abstract

Sodium-cooled fast reactors are an important component of India's move towards energy security. The Fast Breeder Test Reactor (FBTR) has been successfully operated for over 22 years, and the construction of a Prototype Fast Breeder Reactor (PFBR) has been taken up. Future development of Fast Reactor technology depends to a large extent on the economics, safety and waste management issues. The targets important for economics have been identified as reduction in capital costs, higher burn-up fuels, higher temperatures of operation, longer life and higher breeding ratios. These targets can be achieved with significant improvements in performance of materials, especially of Alloy D9 (15Cr-15Ni-0.2Ti), a titanium modified austenitic stainless steel, currently used for fuel cladding. Through research programmes implemented to improve the void swelling resistance of Alloy D9, it has been established that certain solute additions are essential in association with thermomechanical treatments for conferring swelling resistance. Research work conducted on refinement of Alloy D9 composition and thermomechanical treatments aimed at understanding irradiation effects, corrosion, mechanical properties and weldability at IGCAR Kalpakkam along with modelling studies for the prediction of weld behaviour is reported in the present paper. It is concluded that a significant rise in fuel burn-up can be achieved with the use of a new generation "InD9" alloy for fuel cladding. stages: pressurised heavy water reactors of the CANDU type; sodium-cooled fast reactors; thorium-based nuclear reactors. The vast thorium reserves in the country demand that the third stage that can make use of it be introduced as early as feasible. Design efforts on accelerator driven systems are being taken up to ensure in situ incineration of longlived fission products and production of fissile U 233 from fertile U 232 . At present, the transition from the fast test reactor stage where a 40 MW (thermal) was successfully operated for over 22 years, to a 500 MW(e) prototype reactor is being made. In India, fast reactors have a minimum power potential of 530 GW(e). This stage is crucial since it will provide the necessary experience and fuel for the third stage and beyond, with a power generation potential that is estimated to be in excess of 150 trillion watts. The chosen technology for this crucial 2 nd stage is sodium-cooled fast neutron spectrum reactors for generation of electricity.In order that the nuclear option is sustainable it is necessary that improved design targets be achieved: reduction in capital cost, high burn-up fuel, longer lifetime of the reactor, higher operating temperature and higher operating performance. Innovative approach is required to achieve these targets. Materials science, engineering and technology play a significant role when coupled with robust design, engineering development, instrumentation and control and robust safety approaches.Over the years, since the discovery of radioactivity, there has been a paradigm shift in the app...

Kinetics of dynamic recrystallization in Ti-modified 15Cr–15Ni–2Mo austenitic stainless steel

“…Titanium modified 15Cr-15Ni-2Mo austenitic stainless steel, commercially called Alloy D9, is chosen as the structural material for the prototype fast breeder reactor (PFBR) which is being developed in India [4,5]. The alloy is selected owing to its excellent resistance to radiation induced void swelling.…”

“…The alloy is selected owing to its excellent resistance to radiation induced void swelling. Industrial thermo mechanical processing such as forging, extrusion, rolling for this steel is conducted to fabricate various components for in-core applications as the fuel cladding and in the hexagonal subassembly wrapper of the PFBR [4,5]. Reliability and in-reactor performance of the components primarily depend on microstructural development which in turn is governed by the hot working conditions.…”

Development of Stainless Steels in Nuclear Industry: With Emphasis on Sodium Cooled Fast Spectrum Reactors History, Technology and Foresight

“…In a typical Fast Nuclear Reactor industry, like in PFBR of India, 90% of the components in the reactor assembly consist of austenitic stainless steel. The design of reactor components is carried out based on in-depth understanding [7][8][9][10][11][12][13][14] of the austenitic stainless steels under high temperature, irradiation and 60-80 long years of service of the reactors. The stainless steels are used for two major components of the reactor assembly: the core components and the structural materials-i.e., the out-of-core components.…”

Fast Reactor Technology for Energy Security: Challenges for Materials Development

“…The first stage of nuclear power programme has been in the commercial domain for several decades and it has achieved an installed capacity of 4780 MWe. Sodium cooled fast reactors from the second stage of the programme will provide the necessary experience and fuel for the third stage, with an estimated power generation potential [2] in excess of 63,000 MWe. India has made rapid strides in developing SFR technology.…”