Monte Carlo Evaluation of Dose Enhancement Due to CuATSM or GNP Uptake in Hypoxic Environments with External Beam Radiation.

Purpose: Most solid tumors contain areas of chronic hypoxia. Gold nanoparticles (GNP) have been extensively explored as enhancers of external beam radiation; however, GNP have lower cellular uptake in hypoxic conditions than under normoxic conditions. Conversely, the chelator diacetyl-bis (N(4)-methylthiosemicarbazonato) copper II (CuATSM) deposits copper in hypoxic regions, allowing for dose enhancement in previously inaccessible regions.

Tritium Atom Exchange May Be Responsible for Activity Decrease in Plastic Liquid Scintillation Vials.

Detection and measurement of low-energy beta particles is commonly achieved by liquid scintillation counting, in particular for low-level tritium samples. When samples are contained in plastic scintillation vials for long-term storage, the tritium activity in the vials has been found to decrease faster than expected from its natural radioactive decay. Different explanations for this observation have attributed some of these tritium activity losses to diffusion of the sample, degradation of the LSC cocktail, and the potential long-term changes in quenching effects of the LSC cocktail.

'Why' transforms information transfer into effective communication in radiological protection.

As scientists and professionals, we have been trained to present and lecture in front of an audience of similarly instructed peers, we subject our manuscripts to peer-review, and we mentor the next generation of radiological protection professionals to adopt the same methods of information transfer we equate with 'scientific communication.' The scientific community clearly has developed effective and efficient means to share progress in a given field of study. However, current efforts to improve our success in achieving public understanding of our most important and pertinent conclusions, and in communicating the 'risks' associated with low or moderate exposures to ionising radiation indicate the realisation that we have not been similarly successful in our interactions with the general public.

Developing Detection DecisioNS on the Absence or Presence of a Radiological Source using a Bayesian Interaction Model.

Bayesian statistics have been used in various health physics applications, but only limited material exists on the development of a decision threshold for simple gross count measurements using Bayesian statistics. Bayesian modeling specifies a logical procedure for processing information and provides the means to obtain abstract statistical knowledge about the data in question. A Bayesian interaction model was developed to analyze gross count measurements.

Professional ethics in radiological protection.

Professionals in the field of radiological protection from sources of ionising radiation are subject to various codes of ethics published by the professional organisations and associations representing the community of radiological scientists and practitioners. The community and its individual members accept the codes' terms and conditions, and understand the professional consequences of non-compliance. However, while these codes of ethics may be prescriptive with respect to the general understanding of 'ethical behaviour' or 'professional conduct' of radiological protection professionals, they often provide little guidance on an ethical decision making process when conflicting interests and intentions require professional judgment.

Investigation of Dose Rates Exterior to an Above-Ground Waste Storage Facility Using Radiation Transport Models.

The dose rate profile at different heights above the ground and as a function of distance from the north, west, and south walls of an above-ground waste storage facility was analyzed using the Monte Carlo n-Particle Transport eXtended (MCNPX) radiation transport code. The waste storage facility houses 9,996 waste barrels of conditioned waste. The facility has concrete shielding added to the building walls on the north, west, and east sides, with no such additional shielding towards the roof or the south side wall; instead, the distance from the first row of barrels to the wall is extended to allow for maneuverability of a crane on the south side.

Fukushima-derived radionuclides in sediments of the Japanese Pacific Ocean coast and various Japanese water samples (seawater, tap water, and coolant water of Fukushima Daiichi reactor unit 5).

We investigated Ocean sediments and seawater from inside the Fukushima exclusion zone and found radiocesium (Cs and Cs) up to 800 Bq kg as well as Sr up to 5.6 Bq kg. This is one of the first reports on radiostrontium in sea sediments from the Fukushima exclusion zone.

Simultaneous Source Detection and Analysis Using a Zero-inflated Count Rate Model.

This paper proposes a novel Bayesian technique that allows for simultaneous source detection and count rate analysis. The technique involves using priors, which include a finite probability that the source count rate is exactly zero. Such priors are called "zero-inflated.

Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources.

A particle counting and detection system is proposed that searches for elevated count rates in multiple energy regions simultaneously. The system analyzes time-interval data (e.g.

Efficacy of common decontamination methods for cleaning contaminated wounds.

Emergency preparedness and response for work with hazardous materials, including radiological materials, necessarily have to involve injuries sustained by the workers. Removing radionuclide contamination from wounds in tissue is essential to minimizing the intake of radiological materials and the internal dose to the individual. This study compares the efficacy of common decontamination methods for removal of Co from contaminated wounds inflicted in pig tissue.

Characterisation of non-constant background in counting measurements.

A 'moving-target' method for characterising background in a counting measurement in which the instantaneous background count rate is a function of time, rather than being fixed, is proposed. This model treats the average Poisson mean in observation period P as coming from a gamma distribution with parameters αP and βP. This model is applied to a large dataset of replicate observations, consisting of 242 (234)U method blank measurements collected over a 2-y period.

Measurement of the tritium concentration in the fractionated distillate from environmental water samples.

Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The current study investigates the relative change in vapor pressure isotope effect in the course of the distillation process, distinguishing it from and extending previously published measurements.

Comparison of the Chernobyl and Fukushima nuclear accidents: a review of the environmental impacts.

The environmental impacts of the nuclear accidents of Chernobyl and Fukushima are compared. In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident. In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, cesium, tellurium).

Clearance monitoring using hand-held devices: operational implementation and challenges.

Clearance monitoring includes all measures taken and measurements performed to ensure that all pertinent regulatory conditions are met for clearance of waste material. For bulk material, only a limited number of monitoring techniques are feasible for providing the necessary proof of compliance in the time frames and at costs commensurate with operator and regulator expectations for decommissioning projects. Operationally, measurements using hand-held devices, such as contamination monitors using scintillator or proportional counter technology, might provide sufficiently short response times at acceptable accuracies to segregate the waste streams according to their level of contamination and allowing for a decision on their further processing.

A plan for the handling of externally contaminated livestock.

Nuclear accidents and access to radiological weapons for terrorist organizations and countries with hostile intentions towards the United States are realistic scenarios in the current global landscape. A dispersion of radionuclides can result from a nuclear weapon detonation or from a nuclear accident occurring in facilities handling or using radioactive material, such as nuclear power reactors. Any target of a radiological dispersal device (RDD) or an attack with a nuclear weapon and the surrounding area of a reactor accident could be subject to a significant amount of fallout and radioactive contamination.