Thorium was discovered in 1828 by the Swedish chemist Jons J. Berzelius. Despite some advantages over uranium for use in nuclear reactors, its main use, in the almost two centuries since its discovery, thorium was res...Thorium was discovered in 1828 by the Swedish chemist Jons J. Berzelius. Despite some advantages over uranium for use in nuclear reactors, its main use, in the almost two centuries since its discovery, thorium was restricted to use for gas mantles, especially in the early 20th century. In the beginning of the nuclear era, many countries had interested on thorium, particularly during the 1950-1970 period. There are about 435 nuclear reactors in the world nowadays. They need more than 65,000 tons of uranium yearly. The future world energy needs will increase and, even if we assumed a conservative contribution of nuclear generation, there will be a significant increasing in the uranium prices occur, taking into account that uranium, as used in the present thermal reactors, is a finite resource. Thorium is nearly three times more abundant than uranium in the Earth＇s crust. Despite thorium is not a fissile material, ^232Th can be converted to ^233U （fissile） more efficiently than ^238U to ^239pu. Besides this, since it is possible to convert thorium waste into non-radioactive elements, thorium is an environment-friendly alternative energy source. Thorium fuel cycle is also inherently resistant to proliferation. Some papers evaluate the thorium resources in Brazil over 1,200,000 metric t. Then, the thorium alternative must be seriously considered in Brazil for strategic reasons. In this paper a brief history of thorium is presented, besides a review of the world thorium utilization and a discussion about advantages and restrictions of thorium use.展开更多
As a main channel for the foreign economic cooperation of China nuclear industry,China Zhongyuan Engineering Corporation (CZEC) has been constantly engaged in technical modifications and management innovations in its ...As a main channel for the foreign economic cooperation of China nuclear industry,China Zhongyuan Engineering Corporation (CZEC) has been constantly engaged in technical modifications and management innovations in its exporting nuclear reactor projects.In the implementation of heavy water research reactor contract in Algeria,CZEC had established a complete and adequate design standards system in compliance with the international standards,and made significant modifications to the reference reactor in the aspects of reactor power and reactor safety,solved quite some technical issues which affected the reactor technical performance.The modifications and improvements enabled the technical parameters,safety features,reactor multipurpose application to attain to the advanced level in the world.In the 300 MWe PWR NPPs in Pakistan,safety features had been updated in line with upgrading regulatory requisites.The design philosophy and technology application demonstrated CZEC's creation and innovation on basis of constant safety enhancement of nuclear power projects.Efforts had also been made by CZEC in promoting China made equipment items and components exportation.展开更多
文摘Thorium was discovered in 1828 by the Swedish chemist Jons J. Berzelius. Despite some advantages over uranium for use in nuclear reactors, its main use, in the almost two centuries since its discovery, thorium was restricted to use for gas mantles, especially in the early 20th century. In the beginning of the nuclear era, many countries had interested on thorium, particularly during the 1950-1970 period. There are about 435 nuclear reactors in the world nowadays. They need more than 65,000 tons of uranium yearly. The future world energy needs will increase and, even if we assumed a conservative contribution of nuclear generation, there will be a significant increasing in the uranium prices occur, taking into account that uranium, as used in the present thermal reactors, is a finite resource. Thorium is nearly three times more abundant than uranium in the Earth＇s crust. Despite thorium is not a fissile material, ^232Th can be converted to ^233U （fissile） more efficiently than ^238U to ^239pu. Besides this, since it is possible to convert thorium waste into non-radioactive elements, thorium is an environment-friendly alternative energy source. Thorium fuel cycle is also inherently resistant to proliferation. Some papers evaluate the thorium resources in Brazil over 1,200,000 metric t. Then, the thorium alternative must be seriously considered in Brazil for strategic reasons. In this paper a brief history of thorium is presented, besides a review of the world thorium utilization and a discussion about advantages and restrictions of thorium use.
文摘As a main channel for the foreign economic cooperation of China nuclear industry,China Zhongyuan Engineering Corporation (CZEC) has been constantly engaged in technical modifications and management innovations in its exporting nuclear reactor projects.In the implementation of heavy water research reactor contract in Algeria,CZEC had established a complete and adequate design standards system in compliance with the international standards,and made significant modifications to the reference reactor in the aspects of reactor power and reactor safety,solved quite some technical issues which affected the reactor technical performance.The modifications and improvements enabled the technical parameters,safety features,reactor multipurpose application to attain to the advanced level in the world.In the 300 MWe PWR NPPs in Pakistan,safety features had been updated in line with upgrading regulatory requisites.The design philosophy and technology application demonstrated CZEC's creation and innovation on basis of constant safety enhancement of nuclear power projects.Efforts had also been made by CZEC in promoting China made equipment items and components exportation.
