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G7 pledges support for nuclear at Italy meeting
The Group of Seven (G7) recommitted its support for nuclear energy in the countries that opt to use it at a Ministerial Meeting on Climate in Italy last month.
In a statement following the April meeting, the group committed to support multilateral efforts to strengthen the resilience of nuclear supply chains, referencing the goal set by 25 countries during last year’s COP28 climate conference in Dubai to triple global nuclear generating capacity by 2050.
Toshihiro Yamamoto, Yoshinori Miyoshi
Nuclear Science and Engineering | Volume 142 | Number 3 | November 2002 | Pages 305-314
Technical Paper | doi.org/10.13182/NSE02-A2309
Articles are hosted by Taylor and Francis Online.
Mechanisms of a positive temperature reactivity coefficient that occurs in a dilute plutonium solution are investigated based on the perturbation theory and the four-factor formula. The temperature coefficient of a solution fuel is positive if the adjoint flux increases with neutron energy between 0.05 and 0.2 eV. As compared to 239Pu, 241Pu has a tendency to make the temperature coefficient of a plutonium solution positive because of the energy dependence of the capture cross section of 241Pu. As 241Pu in a plutonium solution decays into 241Am with time, the temperature coefficient of the solution becomes more positive. Since the capture cross sections of most neutron absorbers such as boron and gadolinium decrease with increasing neutron energy between 0.05 and 0.2 eV, soluble absorbers in a plutonium solution make the temperature coefficient positive for higher-concentration plutonium solutions. Cadmium and samarium dissolved in a dilute plutonium solution can exceptionally keep the temperature coefficient negative because of the energy dependence of the capture cross sections. A fixed neutron absorber generally makes the temperature coefficient of a plutonium solution negative regardless of the property of absorber materials.