Medical isotope production, research reactors and their contribution to the global xenon background.

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans the testing of nuclear explosive devices underground, in the atmosphere and underwater. Two main technologies, radionuclide and seismo-acoustic monitoring, are deployed in the International Monitoring System used for the verification of the CTBT. Medical isotope production from fission-based processes is the dominant contributor to a worldwide background of radioxenon.

Particle Density Using Deposition Filters at the Full Scale RDD Experiments.

During the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials carried out in Suffield, Alberta, Canada, several suites of detection equipment and software models were used to measure and characterize the ground deposition. The FSRDD Field Trials were designed to disperse radioactive lanthanum of known activity to better understand such an event. This paper focuses on one means of measuring both concentration and the particle size distribution of the deposition using electrostatic filters placed around the trial site to collect deposited particles for analysis.

Deposition Measurements From the Full-Scale Radiological Dispersal Device Field Trials.

In 2012, Defence Research and Development Canada led a series of experiments, titled the Full-Scale Radiological Dispersal Device Field Trials, in which short-lived radioactive material was explosively dispersed and the resulting plume and deposition were characterized through a variety of methods. Presented here are the results of a number of measurements that were taken to characterize the radioactive ground deposition. These included in situ gamma measurements, deposition filter samples, and witness plate measurements that were taken in situ with handheld beta survey meters.

Real Time in Situ Gamma Radiation Measurements of the Plume Evolution from the Full-Scale Radiological Dispersal Device Field Trials.

During the Full-Scale Radiological Dispersal Device Field Trials carried out in Suffield in 2012, several suites of detection and sampling equipment were used to measure and characterize the explosive dispersal of the short half-life radioactive tracer Lanthanum-140 ((140)La). The equipment deployed included networks of in situ real-time radiation monitoring detectors providing measurements of different sensitivities and characteristics. A dense array of lower sensitivity detectors was established near field, ranging from 10 to 450 m from the detonation location.

Testing of an automatic outdoor gamma ambient dose-rate surveillance system in Tokyo and its calibration using measured deposition after the Fukushima nuclear accident.

An in-situ fixed point radioactivity surveillance network has been developed at the Radiation Protection Bureau, Health Canada. The network consists of a number of spectrometric NaI(Tl) detectors measuring, in real-time, ambient gamma dose-rate. The present paper describes the gamma dose-rate monitoring by one detector installed at the Canadian embassy in Tokyo during the Fukushima nuclear accident.

HPA axis activation and neurochemical responses to bacterial translocation from the gastrointestinal tract.

Stress can cause migration of indigenous bacterial flora from the gut to the peritoneum, a phenomenon known as bacterial translocation. Destruction of the cell walls of gram-negative bacteria can result in the production of endotoxin (lipopolysaccharide, LPS), which is the likely cause of sepsis. Exogenously administered LPS can activate the hypothalamo-pituitary-adrenal (HPA) axis as well as brain noradrenergic and indoleaminergic systems.