Development of a boron-copper neutron absorber composite

Technical Report · Wed May 01 04:00:00 EDT 1991

DOI:https://doi.org/10.2172/5925927· OSTI ID:5925927

Wiencek, T C; Thresh, H R; Summers, J R

This report describes the fabrication of a new boron-copper neutron absorbing material that was developed to meet the upgrading needs of the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory. To increase the intensity of the neutron beams from the IPNS, the target uranium was changed from depleted uranium to uranium enriched to 77.5% {sup 235}U. To keep the multiplication factor, k{sub eff} (number of fissions in one generation/number of fissions in preceding generation) at a safe level, a new neutron absorber material was needed. The previous materials, boral and cadmium, could not meet the new requirements and a search of the literature showed that no currently available material was acceptable. With previous powder metallurgy used as a base, the composite was fabricated with 43 vol. % {sup 10}B (81% enriched {sup 10}B) and the balance copper and voids. The powder metallurgy techniques was followed by hot-rolling the composite to a sheet. The material composed of boron particles dispersed in a pure copper matrix and clad with pure copper on both sides, exhibits the following properties: Loadings up to 43 vol. % boron, with the balance copper and voids. A loading of 0.5 {times} 10{sup 22}{sup 10}B atoms/cm{sup 2} in sections as thin as 0.067 in. (1.7 mm), with copper cladding as thin as 0.010 in. (0.25 mm). Formability to radii as small as 2.1 in. (53.3 mm). No observed reaction between boron and the copper matrix and cladding at temperatures up to 900{degrees}C for times as long as 7 h. Retains structural integrity at 900{degrees}C.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5925927
• Report Number(s): ANL-91/44; ON: DE92007416
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
070201* -- Radiation Sources-- Design
Fabrication & Operation
36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
BORON COMPOUNDS
COPPER COMPOUNDS
DESIGN
FABRICATION
NEUTRON ABSORBERS
NEUTRON SOURCES
PARTICLE SOURCES
PULSED NEUTRON TECHNIQUES
RADIATION SOURCES
TRANSITION ELEMENT COMPOUNDS