Radiological Dose Assessment of the Landfill Disposal of Consumer Products Containing Naturally Occurring Radioactive Materials in South Korea

Mercy Nandutu,Juyoul Kim

doi:10.3390/app11157172

Abstract

Naturally occurring radioactive materials (NORMs) are long-lived radioactive elements such as uranium, thorium, and potassium, and theirdecay products. They are abundant in natural rocks and minerals. In this study, we conducted a radiological dose assessment of the disposal of consumer products (CPs) containing NORMs at landfills and incinerators in South Korea. Household wastes were categorized as combustible and noncombustible on the basis of activity concentrations (ACs) ranging below and above 1 Bq/g, respectively. Analysis data were obtained from previous literature and the Nuclear Safety and Security Commission (NSSC) of South Korea, and statistical analysis was performed using an interval plot and 95% confidence interval of mean for each category as an input. Using RESRAD computer codes for noncombustible CPs with AC below and above 1 Bq/g, we found out that the dose rate was below and above 1 mSv/y, respectively. The RESRAD-OFFSITE results showed that the dose incurred during the study period for both ranges of AC was all below the public dose limit of 1 mSv/y. NORM and LegacY Site Assessment (NORMALYSA) code was used to validate the result of the RESRAD-ONSITE code, and the results showed that the dose was equal to and above 1 mSv/y for ACs below and above 1 Bq/g, respectively. HotSpot code was used for dose evaluation to offsite residents from incineration of combustible CPs, and the resulting dose was below 1 mSv/y. These findings can be used as a guideline for managing public exposure from landfill sites with varying ACs ranges. Therefore, the competent authority should ensure that criteria and protection measures are established for people who live within a distance of 10 km from incinerators and landfill sites that are contaminated with consumer products containing NORMs.

Highlights

Naturally occurring radioactive materials (NORMs) and LegacY Site Assessment (NORMALYSA) code was used to validate the result of the RESidual RADioactive (RESRAD)-ONSITE code, and the results showed that the dose was equal to and above 1 mSv/y for activity concentrations (ACs) below and above 1 Bq/g, respectively
There are two ways people can be exposed to NORMs: external exposure, where the source remains outside the body, and internal exposure, where radioactive material is carried into the body through inhalation, ingestion, or absorption
The offsite resident was pathway was used in this study because one of the NORM used was potassium 40, which assumed to live within the vicinity of a landfill site but does not eat or drink water from emits both beta particles and gamma rays that humans are exposed to externally

Summary

Introduction

In most human activities involving minerals and raw materials, exposure to these radionuclides is not significantly higher than normal background levels Human activities such as uranium mining can result in significantly high radiation exposures that may require regulation. Chronic NORM exposure exceeding the general public’s exposure guidelines or occurring in the absence of proper safety precautions may result in delayed effects such as the development of certain cancers [2]. These NORMs can be found in a variety of applications, ranging from household to industrial applications, and their activity concentration (AC) can be increased because of human activities and industrial processes [3]. This uncontrolled disposal exposes the public to a significant amount of radiation

Results

Discussion

Conclusion