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The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
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Article explores emerging trends in health physics
Key developments, emerging trends, challenges, and innovations in the field of health physics are the topic of a recently published article in Health Physics Journal. The authors of “The Future of Health Physics: Trends, Challenges, and Innovation,” Lekhnath Ghimire and Edward Waller, write that they hope to “foster dialogue and collaboration for the unpredictable yet exciting journey ahead” in health physics.
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.