• Journal of Korean Society for Atmospheric Environment
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• v.10 no.E
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• pp.299-302
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• 1994

At a nuclear power plant, environmental radioactivity monitoring is routine work for the radiation safety management For the environmental monitoring of tritium($^3$H) activity in water sampled liquid scintillation counting( LSC) method is applied to measure low- energy beta activity from tritium in the samples. The $^3$H activity is measured using the BECKMAN 5801 system at the KRISS( Korea Research Institute of Standards and Science) for evaluating the lower limits of detection( LLD) of $^3$H measurement and the measuring capability of low-level $^3$H activity at four nuclear Power Plant sites. The LSC systems used for low-level $^3$H activity measurements at the nuclear Power Plants are confirmed to satisfy throughout an intercomparison study under the experimental arrangements by the KRISS.

• Ocean Science Journal
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• v.43 no.1
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• pp.39-48
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• 2008

Tritium ($^3H$ or T) has been produced mostly by atmospheric nuclear weapon tests, and entered the ocean in the form of water (HTO). As tritium exists as water itself, it has been regarded as an ideal tool to study the transport of water masses. In April 2001 we collected water samples in the western Japan Basin (WJB) for tritium and helium measurement. The timely sampling provided direct evidence of the bottom water formation, resulting in the drastic increase in tritium concentration from 0.3 TU in 2000 to 0.67 TU in 2001. Considering that the new bottom waters were found mostly in the WJB, it implies that maximum 1% of the whole bottom layer below 2600 m should be replaced with the surface water during the severely cold winter 2000 2001. $^3H-^3He$ age, showing the elapsed time since the water left from the surface, can be used to calculate oxygen utilization rate by dividing AOU by the age. Under the condition of 90% oxygen saturation in the surface water, the integration of OUR in the water column below 200 m yields net oxygen consumption of 12 mol $(O_2)m^{-2}yr^{-1}$, which corresponds to the export production of $99\;g\;C\;m^{-2}yr^{-1}$. This estimate is comparable to a previous estimate based on satellite data and implies that the ratio of export to primary production(f-ratio) is as high as 0.5 in the WJB.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.27-33
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• 1987

The environment and biological studies of tritium have been carried out in the advanced countries since the mid 1950's. In the case of a potential tritium exposure, the usual procedure is trifium bioassay (as HTO) in human urine in order to determine the amount of tritium deposited in the body called tritium body burden. The maximum permissible body burden(MPBB) of tritium in total body is about $30{\mu}Ci/{\ell}$ for body tissue. In the bioassay, the most common investigation level for detection of tritium in urine is 1/10th of MPBB. For this bioassay project, the first priority is given to obtaining a quench correction curve. This consideration is necessary because of the variability in color of human urine specimens. Quenching effect in this case mainly is caused by the absorption of scintillation light flashes by the urine sample. By the least squares method on the statistical basis, an estimated formula for quench correction curve was determined to be Y = 0.771 + 1.836 ${\tmes}10^{-4}$X, where the efficiency(Y) was ranged from about 12% to 31% in the liquid scientillation counting. In this paper, a brief theory concerning the biological half-life of tritium and the retention formula to apply to systematically distributed tritium are described.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.145-152
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• 1994

As it has been reported that the depolarization induced acetylcholine(ACh) release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor and various lines of evidence indicate the $A_2-receptor$ is present In hippocampus, this study was undertaken to delineate the role of adenosine receptors on hippocampal ACh release. Slices from the rat hippocampus were equilibrated with $[^3H]-choline$ and the release of the labelled product, $[^3H]-ACh$, which evoked by electrical stimulation(3 Hz, $5\;Vcm^{-1}$, 2 ms, rectangular pulses) was measured, and the influence of various agents on the evoked tritium outflow was Investigated. Adenosine$(0.3{\sim}100\;{\mu}M)$ and CPA$(0.1{\sim}30\;{\mu}M)$ decreased the $[^3H]-ACh$ release in a dose-dependent manner without changing the basal rate of release. DPCPX$(1{\sim}10\;{\mu}M)$, a selective $A_1-receptor$, antagonist, increased the $[^3H]-ACh$ release in a dose related fashion with slight increase of basal tritium release. And the effects of adenosine and CPA were significantly inhibited by $DPCPX(2\;{\mu}M)$ treatment. CPCA, a specific $A_2-agonist$, in concentration ranging from 0.3 to 30 ${\mu}M$, decreased the evoked tritium outflow, and these effects were also abolished by $DPCPX(2\;{\mu}M)$ treatment. But the CPCA effects were not affected by $DMPX(2\;{\mu}M)$, a specific Aa-antagonist, treatment. However, CGS 21680c, a recently introduced potent $A_2-agonist$, in concentration ranging from 0.1 to $10{\mu}M$, did not alter the evoked tritium outflow. These results indicate that the decrement of the evoked ACh release by adenosine is mediated by $A_1-heteroreceptor$, but $A_2-adenosine$ receptor is not involved in ACh release in the rat hippocampus.

• Journal of Radiation Protection and Research
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• v.33 no.3
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• pp.113-120
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• 2008

In this study, The TRITGO code was introduced, which can predict the amount of tritium production, it's transport, removal, distribution and the level of contamination for the produced hydrogen by the tritium on the VHTR (very high temperature gas cooled reactor). The TRITGO code was improved so that the permeation to the IS Iodine Sulfide) loop for producing the hydrogen can be simulated. The contamination level of the produced hydrogen by the tritium was predicted by the improved code for the VHTR with 600MW thermal power. The contamination level for the produced hydrogen by tritium was predicted as 0.055 Bq/$H_2-g$. This level is three order of lower than the regulation value of 56 Bq/$H_2-g$ from Japan. From this study, the following results were obtained. it is important that the fuel coating (SiC layer) should be kept intact to prevent the tritium from releasing. Also it is necessary that the level of impurity such as 3He and Li in the helium coolant and the reflector consisting of the graphite should be kept as low as possible. It was found that the capacity of the purification system for filtering the impurities directly from the coolant will be the important design parameter.

• Progress in Medical Physics
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• v.5 no.1
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• pp.75-85
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• 1994

As we enter the 2000s, there are four nuclear power units of the pressurized heavy water reactor-type in the commercial operation at the Wolsung Nuclear Power Plant(NPP) site where a larger amount of tritium ($\^$3/H) is released inevitably to the site environment. This radioctive nuclide is easily distributed throghout our environment because of its ubiquitous form as tritiated water (HTO) and its persistence in the environment. Tritum has certain characterisitics that present unique challenges for beta radiation dosimety and health risk assesment. In this paper, therefore, a variety of matters on tritium are considered and reviewed in terms of its characteristics and sources, metabolism and dosimetry, microdosimetry, radiobiology, risk assessment, and transport and cycling in the environment, etc.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.139-142
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• 2001

The one of important parameter involved in the calculation of internal radiation dose to the human body is the biological half-life of the radionuclide. The biological half-life is population specific and may differ from one population group to another. So the effective half-life of tritium exposure based on urinal bioassay measurement of Wolsong Nuclear Power Plants was investigated and studied.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.45-54
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• 2005

A dynamic compartment model was developed to appraise the level of the contamination of agricultural plants by accidentally released tritium from nuclear facility. The model consists of a set of inter-connected compartments representing atmosphere, soil and plant. In the model three categories of plant are considered: leafy vegetables, grain plants and tuber plants, of which each is modeled separately to account for the different transport pathways of tritium. The predictive accuracy of the model was tested through the analysis of the tritium exposure experiments for rice-plants. The predicted TFWT(tissue free water tritium) concentration of the rice ear at harvest was greatly affected by the absolute humidity of air, the ratio of root uptake, and the rate of rainfall, while its OBT(organically bound tritium) concentration the stowing period of the ear, the absolute humidity of air and the content of hydrogen in the organic phase. There was a good agreement between the model prediction and the experimental results lot the OBT concentration of the ear.

• Archives of Pharmacal Research
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• v.1 no.1
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• pp.27-32
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• 1978

A procedure of $^3H$-radio labeling synthesis for the dammarane triterpene glycosides of Korean ginseng was established by using the ginsenoside $Rg_1$ as starting material. The protons in $C-{11}$ and $C_{13}$ of the aglycone moiety of the glycoside were exchanged with tritium by keto-enol tautomerization of 12-keto-ginsenoside $Rg_1$ which was prepared by partial acetylation, Sarett oxidation and saponification, producing nona-acetate, nonaside $Rg_1$. The acety1-ketone and 12-keto-derivative of ginsenotritated ketone was reduced by metallic sodium and isoproponol to produce the end product $^3H$-ginsenoside $Rg_1$ with 3% radio-chemical recovery in one experiment.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2564-2569
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• 2021

The neutronic analysis of Helium Cooled Ceramic Reflector (HCCR) breeding blankets has been performed using the 3D Monte Carlo code MCNPX and ENDF nuclear data library. This study aims to reduce ⁶Li percentage in the breeder zones as much as possible ensuring tritium self-sufficiency. This work is devoted to investigating the effect of ⁶Li percentage on the HCCR breeding blanket's neutronic parameters, such as neutron flux and spectrum, Tritium Breeding Ratio (TBR), nuclear power density, and energy multiplication factor. In the ceramic breeders at the saturated thickness, increasing the enrichment of ⁶Li reduces its share in the tritium production. Therefore, ceramic breeders typically use lower enriched Li from 30% to 60%. The investigation of neutronic analysis in the suggested geometry shows that using 60% ⁶Li in Li₂TiO₃ can yield acceptable TBR and energy deposition results, which would be economically feasible.