Respiratory protection strategies for the public in emergency response.

A strategy was established to minimize the stochastic effects of internal and external exposure to radioactive substances by wearing respiratory protection equipment (RPE) during an emergency evacuation. During the evacuation of residents in the event of a nuclear power plant accident, the stochastic effects of internal exposure caused by the inhalation of radioactive aerosol and external exposure due to accumulated radioactive particles in the filter medium of a mask must be minimized. The radioactivity concentration along an evacuation route considers atmospheric dispersion and the resuspension of particles deposited on surfaces.

Dead layer estimation of an HPGe detector using MCNP6 and Geant4.

In this study, Monte Carlo simulations were used to calculate the full-energy peak efficiency of a p-type coaxial high-purity germanium (HPGe) detector. The HPGe detector was modeled using MCNP6 and Geant4, and the thickness of the dead layer of germanium crystals was estimated for an accurate simulation. The dead layer was divided into front and side components, where a point source and a Marinelli beaker source were used to estimate each dead layer thickness.

Semi-mechanistic analysis of emergency planning zones for 20 MWe lead-cooled fast reactor by hypothetical accidents during Korea's arctic exploration.

Small modular reactors or micro modular reactors have been considered as an alternative power source for merchant ships because of minimal carbon emission and a long lifecycle without refueling. Ahead of the operation, however, their emergency planning zones (EPZs) should be optimally set and approved to ensure both radiological safety and cost efficiency in case of nuclear accidents. Thus, the required size of EPZs was analyzed based on semi-mechanistic assumptions for hypothetical accidents with MicroURANUS, a micro modular fast reactor type of 20-MW lead-bismuth-cooled, used to power an icebreaker during Korea's Arctic missions.

SPATIAL DISTRIBUTION ANALYSIS AND DOSE ASSESSMENT OF THE RADON EMITTED FROM THE MONAZITE-CONTAINING MATTRESS IN GENERAL RESIDENTIAL SPACE BY CFD METHODS.

Recently, mattresses produced from radon-emitting monazite raw materials in the manufacturing process were found to be releasing radon, and a survey by the Korean Nuclear Safety and Security Commission indicated that some of these products exceeded safety standards. In this study, the distribution of the radon resulting from radon-emitting mattresses was evaluated. The computational fluid dynamics (CFD) code FLUENT was used to analyze the distribution of radon in a general living space, and to assess the exposures of residents.

Gamma-Ray Sensor Using YAlO(Ce) Single Crystal and CNT/PEEK with High Sensitivity and Stability under Harsh Underwater Conditions.

A new gamma-ray sensor, which could be employed in harsh underwater conditions, was developed using YAlO(Ce) single crystal and carbon nanotube reinforced polyetheretherketone (CNT/PEEK). The sensor is compact, highly sensitive and stable, by providing real-time gross counts and an accumulated spectrum for fresh, saline, or contaminated water conditions. The sensor was tested in a water tank for quantification of the limit of detections.

Multi-channel plastic-scintillator-based detection system for monitoring tritium in air.

To overcome the limitations of the ionization chamber-based tritium monitor, a design for a multichannel plastic scintillator-based detection chamber for monitoring tritium in air is proposed. The performance of the chamber was characterized by Monte Carlo-based calculations with various design parameters such as thickness of the plastic scintillator (t) and number of channels (n). We considered the volume and detection efficiency of the chamber to evaluate the performance of the detector.

Optimizing UAV-based radiation sensor systems for aerial surveys.

In this study, we qualitatively and quantitatively analyzed unmanned aerial vehicle (UAV)-based radiation sensor systems suitable for specific survey missions. We examined a variety of UAVs, radiation sensors, and radiological survey missions; after reviewing previous studies that developed and conducted field tests, we categorized them by mission and suggested suitable types of UAVs and radiation sensors for each mission. To quantitatively analyze various system designs previously suggested, we proposed a new figure of merit (FOM) formula that can explain the mutual effects of parameters of both radiation sensors and UAVs on system performance.

In situ beta radiation monitoring system with enhanced efficiency for water samples from decommissioned nuclear environment.

A nuclear environment, including decommissioning activity contains various radioactive nuclides such as pure beta emitters. These radionuclides should be monitored to ensure radiological safety. In particular, beta radionuclides, such as H and C, can cause internal exposures and should be managed more strictly in terms of health physics.

Radiological impact assessment for workers on treatment of radioactive spent resin from heavy water reactors.

In heavy water reactors, radionuclides are generated, then removed and treated by ion exchange resin. The disposal cost of spent resin is expected to increase because of the saturation of the existing storage capacity. In this study, a spent resin treatment process using microwaves is proposed, and a radiological safety assessment and cost evaluation of the spent resin treatment process are performed.

Development of AN On-site, Rapid, Environmental Radiation-distribution Monitoring System for Decision Making during a Radiation Emergency.

An on-site, rapid, measurement-based, radiation-distribution visualization system with radionuclide recognition was developed for quick decision making during a radiation emergency. After scanning of the area was complete, radionuclide-specific radiation-distribution contours were displayed in two and three dimensions on a map of the measurement area, in a few tens of seconds, by clicking once on an execution file, which was programmed using MathWorks' MATLAB software. The contours were fundamentally verified using Cs and Co standard sources.

Eco-friendly one-pot synthesis of Prussian blue-embedded magnetic hydrogel beads for the removal of cesium from water.

A simple one-step approach to fabricating Prussian blue-embedded magnetic hydrogel beads (PB-MHBs) was fabricated for the effective magnetic removal of radioactive cesium (Cs) from water. Through the simple dropwise addition of a mixed aqueous solution of iron salts, commercial PB and polyvinyl alcohol (PVA) to an ammonium hydroxide (NHOH) solution, the formation of hydrogel beads and the encapsulation of PB in beads were achieved in one pot through the gelation of PVA with in situ-formed iron oxide nanoparticles as the cross-linker. The obtained PB-MHBs, with 43.

Feasibility and its characteristics of CO2 laser micromachining-based PMMA anti-scattering grid estimated by MCNP code simulation.

Background: Anti-scattering grid has been used to improve the image quality. However, applying a commonly used linear or parallel grid would cause image distortion, and focusing grid also requires a precise fabrication technology, which is expensive.

Objective: To investigate and analyze whether using CO2 laser micromachining-based PMMA anti-scattering grid can improve the performance of the grid at a lower cost.

Environmental gamma radiation analysis for Ulsan city with the highest nuclear power plant density in Korea.

This study presents a real-time measurement-based rapid radiation distribution visualization system for radionuclide recognition, which can quickly scan a contaminated environment. The system combines a portable detector with a digital map and a program for quick data treatment. Radiation information at the measurement location is transferred between a detector and a laptop.

The radioactivity estimation of 14C and 3H in graphite waste samples of the KRR-2.

The radioactivity of (14)C and (3)H in graphite samples from the dismantled Korea Research Reactor-2 (the KRR-2) site was analyzed by high-temperature oxidation and liquid scintillation counting, and the graphite waste was suggested to be disposed of as a low-level radioactive waste. The graphite samples were oxidized at a high temperature of 800 °C, and their counting rates were measured by using a liquid scintillation counter (LSC). The combustion ratio of the graphite was about 99% on the sample with a maximum weight of 1g.