The Gesellschaft für Anlagen-und Reaktorsicherheit(GRS)gGmbH as the main technical support organization for the German Federal Government in nuclear safety has been dealing with small modular reactors(SMRs)for ab...The Gesellschaft für Anlagen-und Reaktorsicherheit(GRS)gGmbH as the main technical support organization for the German Federal Government in nuclear safety has been dealing with small modular reactors(SMRs)for about one decade since SMRs are one interesting option for new builds in most countries worldwide which continue to use nuclear energy for commercial electricity production.Currently four different SMR designs are in operation,four in construction,one is licensed,and further 12 are in a licensing process.In this paper,definitions,history,and current developments of SMRs are presented.Subsequently,selected trends of SMR development such as factory fabrication and transport,compactness and modularity,core design,improved core cooling,exclusion of accidents,features for preventing and limiting the impact of severe accidents,economic viability,competitiveness and licensing are discussed.Modeling gaps of the GRS simulation chain programs with a view to applications in nuclear licensing procedures are identified and a strategy for closing these gaps is presented.Finally,selected work on the extension and improvement of the simulation chain and first generic test analyses are presented.展开更多
Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a tran...Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a transition between Generations III+ and IV in order to make nuclear energy more competitive with other energy sources, including renewables. In this study, the SMR NuScale, one of the most promising projects today, is investigated for its conversion into a U-233-producing reactor through the Radkowsky seed-blanket fuel element concept, applied in the Shippingport reactor, in a parametric study. Initially, a validation of the reference reactor (NuScale) was carried out with data from technical documents and papers, thus demonstrating the agreement of the computational model carried out with the SERPENT code. Then, a parametric study is carried out to define the area of the seed and blanket region, proportions of enrichment and pitch length. Finally, a comparison is made between the production of U-233, TRU reduction, burn-up extension and neutronic and thermohydraulic safety parameters. This study demonstrates an improvement in the conversion factor and a considerable reduction in the production of TRU, in addition to the production of U-233 with a low proportion of other uranium isotopes that can lead to the beginning of the thorium cycle with already consolidated technologies.展开更多
基金the works and results of the following research projects RS1521,RS1561,RS1574,RS1576,RS1577,RS1578,RS1579 and RS1589 which are funded by the German Federal Ministry for Economic Affairs and Energy(BMWi)on the basis of decisions of the German Bundestag。
文摘The Gesellschaft für Anlagen-und Reaktorsicherheit(GRS)gGmbH as the main technical support organization for the German Federal Government in nuclear safety has been dealing with small modular reactors(SMRs)for about one decade since SMRs are one interesting option for new builds in most countries worldwide which continue to use nuclear energy for commercial electricity production.Currently four different SMR designs are in operation,four in construction,one is licensed,and further 12 are in a licensing process.In this paper,definitions,history,and current developments of SMRs are presented.Subsequently,selected trends of SMR development such as factory fabrication and transport,compactness and modularity,core design,improved core cooling,exclusion of accidents,features for preventing and limiting the impact of severe accidents,economic viability,competitiveness and licensing are discussed.Modeling gaps of the GRS simulation chain programs with a view to applications in nuclear licensing procedures are identified and a strategy for closing these gaps is presented.Finally,selected work on the extension and improvement of the simulation chain and first generic test analyses are presented.
文摘Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a transition between Generations III+ and IV in order to make nuclear energy more competitive with other energy sources, including renewables. In this study, the SMR NuScale, one of the most promising projects today, is investigated for its conversion into a U-233-producing reactor through the Radkowsky seed-blanket fuel element concept, applied in the Shippingport reactor, in a parametric study. Initially, a validation of the reference reactor (NuScale) was carried out with data from technical documents and papers, thus demonstrating the agreement of the computational model carried out with the SERPENT code. Then, a parametric study is carried out to define the area of the seed and blanket region, proportions of enrichment and pitch length. Finally, a comparison is made between the production of U-233, TRU reduction, burn-up extension and neutronic and thermohydraulic safety parameters. This study demonstrates an improvement in the conversion factor and a considerable reduction in the production of TRU, in addition to the production of U-233 with a low proportion of other uranium isotopes that can lead to the beginning of the thorium cycle with already consolidated technologies.
