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Title: Design of a subcritical multiplying low-enriched uranium externally driven neutron assembly at the Los Alamos neutron science center

Conference ·
OSTI ID:962264
 [1]
  1. Los Alamos National Laboratory

The Sandia Pulsed Reactor (SPR) has had a long history of supplying short intense neutron bursts to test the survivability of critical weapons components. The most recent version, SPR III, was resurrected in 2005 in support of critical survivability testing for W-76 Life Extension Program and other testing for the Qualification Alternatives to SPR program. SPR has now been decommissioned. The SPR had a cylindrical shape, with an internal cylindrical cavity where samples were placed for testing. The approximate dimensions of the cavity were 16.5 cm radius, and 38.1 cm high. The uniformity of the fluence over the entire volume was {+-} 25%. The nominal fluence was 5.4 {center_dot} 10{sup 14} n/cm{sup 2}, 1 MeV Si equivalent (Si equivalent implies that the neutron spectrum, at energies other than 1 MeV, is weighted by its relative damage potential in silicon), with a pulse duration of 55 microseconds, FWHM. We propose a new facility as a replacement to the SPR pulsed neutron capabilities, utilizing the proton linear accelerator at the Los Alamos Neutron Science Center (LANSCE). Currently, LANSCE provides neutron beams generated by the 800 MeV proton beam, over 13 decades of energy, to five different facilities. LANSCE is in the process of being refurbished; the refurbishment project (LANSCE-R) is funded and due to be completed by 2014. In parallel to the refurbishment, the experimental user program will continue and provide 3000 hours of beam per year. LANSCE is also considering upgrade options in the framework of MaRIE (Materials and Radiation Interactions in Extreme). MaRIE is planned to be the new signature facility for Los Alamos for the foreseeable future. Hence, they expect LANSCE to continue to operate and provide beams for decades t come. They propose to use the 800 MeV proton beam, extracted from the Proton Storage Ring (PSR), to initiate a neutron pulse in a sub-critical multiplying assembly, fabricated from Low-Enriched Uranium (LEU). The reason for using LEU (rather than highly-enriched uranium) is that it is not considered an attractive material that requires a significant investment in security and materials protection.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC52-06NA25396
OSTI ID:
962264
Report Number(s):
LA-UR-08-06256; LA-UR-08-6256; TRN: US0903414
Resource Relation:
Conference: Hardened Electronics and Radiation Technology ; March 30, 2009 ; Albuquerque
Country of Publication:
United States
Language:
English