Development of Field Estimation Technique and Improvement of Environmental Tritium Behavior Model

Self Cite

In order to understand the regional property of tritium concentration in natural water at Hirosaki City, Aomori Prefecture Japan, natural spring water samples were collected from 15 sites in 2016 and tritium concentration was measured by low-level tritium counting procedure using a commercially available solid polymer electrolyte (SPE) tritium enrichment system. The limit of detection of this procedure was approximately 0.06 Bq/L. Findings showed tritium concentrations in natural spring water samples ranged from 0.30 to 0.55 Bq/L with mean value of 0.44±0.08 Bq/L. These results were within the range of reported concentrations in rain and surface and shallow groundwater in Japan including other places of Aomori Prefecture. The presently obtained data could be considered as the background level of the Hirosaki area. The annual effective dose would be negligibly small compared with the annual effective dose limit of 1 mSv, if the committed effective dose equivalent from drinking water to residents was calculated using the highest tritium concentration data.

Section: Introductionmentioning

confidence: 99%

Tritium Concentration in Natural Spring Water Collected at Hirosaki, Japan

Okada

Kuwata

KHEAMSIRI

et al. 2023

Self Cite

“…Distillation is a conventional pretreatment method used in tritium analysis of environmental water samples; however, this method is complicated and involves a time-consuming process requiring 24 h to remove impurities from 1 L of water. Therefore, we have proposed and developed a new measurement development for the analysis of tritium in the environmental samples [5]. In the previous study, the rapid pretreatment method to remove impurities including dissolved ions and organic matter using ion exchange resins and activated carbon was evaluated [6].…”

Section: Introductionmentioning

confidence: 99%

Simple Pretreatment Method for Tritium Measurement in Environmental Water Samples using a Liquid Scintillation Counter

Nakasone

Yokoyama

Takahashi

et al. 2021

Self Cite

The aim of this study is to evaluate quantitatively the effectiveness of the ion exchange resins and activated carbon in tritium measurement. A standard water sample was adjusted to a tritium concentration of 5 Bq L −1 . This sample was stirred with the cation exchange (PCH) and anion exchange (PAO) resins and activated carbon. After stirring the samples, the supernatant in each sample was filtered through 0.45 µm membrane filters. The electrical conductivity in an experimental condition, where the amounts of PCH, PAO, and activated carbon were 0.3 g, 0.3 g, and 0.6 g, respectively, was lower than that of the sample treated by the distillation method. The distillation method requires approximately 12 h to process; however, the same level of results was achieved in 5 min. The tritium concentration in each experiment was within the standard deviation. These results suggested that proposed batch method involving ion exchange resins and activated carbon had negligible effect on tritium measurement. The ion concentration and the total organic carbon for the samples were decreased in 5 min. These results demonstrate the effectiveness of the impurity removal from the sample water by ion exchange resins.

“…Given all of these releases, it would be beneficial to establish a model to better understand the behavior of tritium released into the environment and to improve the analysis method for environmental samples. At present, research is being conducted to improve the tritium transfer model based on a simple compartment model, establish practical parameters, and subsequently estimate tritium transfers in the environment [5]. This paper describes the progress that has been made toward developing new analytical methods in these research fields.…”

Section: Introductionmentioning

confidence: 99%

Preliminary Investigation of Pretreatment Methods for Liquid Scintillation Measurements of Environmental Water Samples Using Ion Exchange Resins

Nakasone

Yokoyama

Takahashi

et al. 2020

Self Cite

This paper presents an evaluation of a rapid pretreatment method for tritium analysis, that uses ion exchange resins (the batch method). The standard water samples were prepared with river water collected in Okinawa, Japan. Powdex resin was used in this study, which is an ion exchange resins in the form of powder beads. First, 100 mL of the standard sample was stirred with the cation exchange (PCH) and anion exchange (PAO) resins, as well as with activated carbon. To determine the optimal stirring time, we tested stirring times of 5, 10, 20 and 30 min. Additionally, to determine a suitable amount of ion exchange resin for environmental water samples, variations in the amount of resin and activated carbon were tested. Under the conditions of Experiment-3 (0.3 g, 0.3 g and 0.6 g of PCH, PAO and activated carbon, respectively) and with a stirring time of 5 min, electrical conductivity values of less than 1 mS m −1 were achieved. These results demonstrate the effectiveness of the removal of impurities in the sample water by ion exchange resins and confirm that such an effect can be achieved during a short period of time (i.e., in 5 min).