Criticality of a {sup 237}Np Sphere

Conference · Tue Jul 22 00:00:00 EDT 2003

OSTI ID:819422

Sanchez, Rene G.; Hayes, David K.; Cappiello, Charlene C.; Myers, William L.; Jaegers, Peter J.; Clement, Steven D.; Butterfield, Kenneth B.

A critical mass experiment using a 6-kg {sup 237}Np sphere has been performed. The purpose of the experiment is to get a better estimate of the critical mass of {sup 237}Np. To attain criticality, the {sup 237}Np sphere was surrounded with 93 wt % {sup 235}U shells. A 1/M as a function of uranium mass was performed. An MCNP neutron transport code was used to model the experiment. The MCNP code yielded a k{sub eff} of 0.99089 {+-} 0.0003 compared with a k{sub eff} 1.0026 for the experiment. Based on these results, it is estimated that the critical mass of {sup 237}Np ranges from kilogram weights in the high fifties to low sixties.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 819422
• Report Number(s): LA-UR-03-5267
• Resource Relation: Conference: ICNC2003 Challenges in the pursuit of global nuclear criticality safety, the 7th international conference on nuclear criticality safety, October 20-24, 2003, Tokai-mura, Japan
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
neptunium
critical mass
fast spectrum
bare
metal
sphere
highly enriched uranium