Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: E. Waller x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

During the past decade, interest has increased in qualifying and quantifying the threat posed to the public by the illegal use of radionuclides. In order to take investigations beyond the laboratory bench into more realistic scenarios, environmental and safety considerations dictate that these studies be performed on stable and benign surrogates. This paper discusses some of these studies, specifically the use of cerium dioxide for actinide ceramics and calcium and natural strontium ceramics for those based on 90Sr.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: T. Cousins, T. Jones, J. Brisson, J. McFee, T. Jamieson, E. Waller, F. LeMay, H. Ing, E. Clifford, and E. Selkirk

Abstract  

In order to detect and locate buried landmines for peacekeeping, the Canadian Department of National Defence (DND), under the Improved Landmine Detection Project, is developing a vehicle-mounted, two-phase mine detection system. The first phase constitutes a suite of detectors used to indicate the possibility of a mine at a particular location (to ±30 cm in accuracy). In the second phase a Thermal Neutron Activation (TNA) system is used to confirm the presence of explosives via detection of the 10.83 MeV gamma-ray associated with nitrogen decay. The TNA system developed for this uses a 100 μg252Cf neutron source surrounded by four 3″×3″ NaI(Tl) detectors. Combining the use of state-of-the art radiation transport codes for design, judicious choice of specialized shielding materials and development of high-rate, fast-pulse processing electronics, has led to a system which can; (i) confirm the presence of all surface- or lightly-buried anti-tank mines in a few seconds to a minute (depending on mass of explosive), (ii) confirm the presence of anti-tank mines down to 20 cm depth in less than 5 minutes, (iii) confirm the presence of large (>100 g nitrogen) anti-personnel mines in less than five minutes, (iv) operate in adverse climatic conditions. These results have been verified in field trials and the system is due to be fielded in 1999.

Restricted access

Abstract  

Inhalation is one of the most important routes for aerosol particles of uranium compounds to enter the body. The main step for uranium to be available for blood circulation and for interaction with bio-molecules is the dissolution of the particles. Particle size effects on dissolution of uranium dioxide and uranium ore were studied in simulated lung fluid using the “batch/filter” method. Samples were fractionated to ten size ranges from <0.43 μm to >10 μm by cascade impaction prior to dissolution experiments. Dependence of dissolution kinetics on particle size and on the amount of uranium trioxide contained in the particles was observed.

Restricted access