Digital Scholarship@UNLV

Title

Nuclear Criticality, Shielding, and Thermal Analyses of Separations Processes for the Transmutation Fuel Cycle

Authors

William Culbreth, University of Nevada, Las VegasFollow
Denis Beller, University of Nevada, Las VegasFollow

Document Type

Grant

Publication Date

2002

First page number:

1

Last page number:

15

Abstract

The remediation of nuclear waste created by conventional fission reactors will rely upon the separation of the waste products for further treatment. The UREX+ process now under review will involve the use of an aqueous chemical process to separate out depleted uranium resulting in a product containing minor actinides, fission products, cesium, strontium, technetium, and iodine. The radioactive decay of strontium and cesium produces roughly half of the thermal and gamma production in spent fuel and the relatively short halflife of isotopes of both of these elements requires storage for about 300 years before heat and radiation decreases to safe levels.

During the separation process, concentrated quantities of fissionable plutonium and americium pose a potential nuclear criticality risk. At each stage in the process, an assessment of the effective neutron multiplication factor, k_eff, will be necessary to prevent the possibility of sustained fission. Candidate storage containers must also be analyzed to assess the need for radiation shielding. The minor actinides generate significant amounts of heat through radioactive decay and proposed storage must be designed to avoid excessive temperatures.

In the continuation of our work with ANL, we will conduct assessments of nuclear criticality, radiation transport for shielding, and thermal analyses of wastes in the Cs/Sr, Pu/Np, and Cm/Am waste streams to assist in the design of the UREX+ process.

Keywords

Americium; Cesium; Criticality (Nuclear engineering); Curium; Neptunium; Plutonium; Radioactive wastes; Separation (Technology); Shielding (Radiation); Strontium; Uranium Recovery by Extraction (UREX)

Controlled Subject

Criticality (Nuclear engineering); Strontium; Separation (Technology)

Disciplines

Chemistry | Nuclear | Nuclear Engineering | Oil, Gas, and Energy

File Format

pdf

File Size

528 KB

Language

English

Rights

COPYRIGHT UNDETERMINED. For more information about this rights statement, please visit http://rightsstatements.org/vocab/UND/1.0/

Repository Citation

Culbreth, W., Beller, D. (2002). Nuclear Criticality, Shielding, and Thermal Analyses of Separations Processes for the Transmutation Fuel Cycle. 1-15.
Available at: https://digitalscholarship.unlv.edu/hrc_trp_separations/20