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The spark of the Super: Teller–Ulam and the birth of the H-bomb—rivalry, credit, and legacy at 75 years
In early 1951, Los Alamos scientists Edward Teller and Stanislaw Ulam devised a breakthrough that would lead to the hydrogen bomb [1]. Their design gave the United States an initial advantage in the Cold War, though comparable progress was soon achieved independently in the Soviet Union and the United Kingdom.
Hoang Hai Nguyen, Jun Nishiyama, Toru Obara
Nuclear Science and Engineering | Volume 194 | Number 12 | December 2020 | Pages 1128-1142
Technical Paper | doi.org/10.1080/00295639.2020.1775433
Articles are hosted by Taylor and Francis Online.
The CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy production) reactor concept was proposed to overcome the disadvantages of current reactor technologies. In this study, a Monte Carlo–based procedure is developed for quantitative comparison of burnup performance and neutronic characteristics between lead bismuth eutectic (LBE)–cooled and sodium-cooled CANDLE reactors to demonstrate the possibility of using sodium coolant in a small CANDLE burning reactor. In this procedure, a neutron transport equation is solved using the MVP code with the JENDL-4.0 library, and the burnup calculation is solved using the MVP-BURN code with the detailed burnup chain. To simulate the fuel-shuffling process, an auxiliary code was developed using Python. The results show that for the same fuel pin design and core volume, changing the coolant from LBE to sodium reduced the keff by 2.3% and the average discharge burnup by 15.6%, due to the softer neutron spectrum and larger neutron leakage fraction. It would be necessary to increase the fuel volume and core radius approximately 38% and 17%, respectively, for criticality in a sodium-cooled CANDLE core.