• Nuclear Engineering and Technology
• /
• v.52 no.9
• /
• pp.2085-2091
• /
• 2020

The license for Kori-1, the first commercial reactor in Busan, Korea, was terminated in June 2017; therefore, preparations are being made for its decommissioning. Because the radioactivity of Bio-shield varies greatly throughout the structure, the doses received by the workers depend on the location, order, and duration of dismantling operations. Thus, a model for evaluating the worker external dose during the dismantling of the Kori-1 bio-shield was developed, and work scenarios for dose assessment were designed. The Dose evaluation code VISIPLAN was used for dose assessment. The dose rate around the bio-shield was evaluated and the level of exposure to the operator was evaluated according to the work scenario. The maximum annual external dose was calculated as 746.86 mSv for a diamond wire saw operator under dry cutting conditions, indicating that appropriate protective measures, such as changing dismantling sequence, remote monitoring, shield installation, and adjustment of work team are necessary for the safe dismantling of the bio-shield. Through these protective measures, it was found that the worker's dose could be below the dose limit.

• Journal of radiological science and technology
• /
• v.41 no.5
• /
• pp.445-450
• /
• 2018

We aim to evaluate safety of radiation by measuring leakage dose and patient(phantom) incident dose of ZEN-PX II dental portable equipment developed by G company. Measurement for leakage dose of equipment is conducted on the top, at the bottom, on the left, on the right and at the back. Dose measurement incident on the subject with the area dosimeter when using the phantom and measurement the leakage dose of equipment when using the phantom are evaluated. Comparing the right with the highest leakage dose as a 0 cm, 25 cm, 50 cm, 75 cm and 100 cm dose measurement at the measurement height of 100 cm, 64.2 uR was reduced to 47.3 uR in the senser mode 0.32sec. Even in film mode it was measured at 414.4 uR and about 27% lower at 162.6 uR. As the result of this study, when the irradiation time is 2 sec the right side dose is 290.5 uR and sensor mode is 0.32 sec the right side dose is 64.2 uR.

• Environmental Mutagens and Carcinogens
• /
• v.22 no.2
• /
• pp.97-105
• /
• 2002

Nowadays a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms are developed and manufactured with safety evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively. This study was carried out to evaluate the single and repeated dose inhalation toxicity and genotoxicity of H menthol (Nicotine free-tobacco free) herbal cigarettes provided by Cigastop Ltd. in ICR mice. In this study, doses which we determined to expose to mice were 40 cigarettes for 6 hours a day to mice in single dose and 20 (high dose), 10 (middle dose) and 5 cigarettes (low dose) a day for 28 days in repeated dose inhalation toxicity, in vivo chromosome aberration test and micronucleus test. The particulate substances from H menthol herbal cigarettes also were gathered and used in the Salmonella typhimurium/microsome assay (Salmonella test; Ames test). We could find neither significant changes between control and treatment groups nor dose-response effects of test material at all except serum Ca level of female middle dose treatment group in repeated dose inhalation toxicity test. In conclusion, H menthol herbal cigarettes, when applied clinically intended dose we used, might not show any toxic and/or mutagenic effect.

• Journal of radiological science and technology
• /
• v.46 no.6
• /
• pp.501-508
• /
• 2023

This study used a adult absorption dose phantom (CIRS model 701-G, USA) made of human equivalent material and the vascular imaging equipment Allura Xper FD 20 (Philips, Netherlands). Optically stimulated luminescent dosimeters (OSLD) were inserted into the anatomical positions corresponding to each organ, and the exposure dose was measured. Dose area product (DAP) and air kerma (AK) measured by the dose meter in the equipment were compared. Continuous imaging was performed at two angles for a total of 20 minutes, with a frame per seconds of 3.75 and 7.5 fps and an FOV of 42 cm, 37 cm, and 31 cm, respectively, under the conditions of fluoflavor I, II, and III, each selected for 5 repetitions. This study was found that selecting a lower fps was the most effective way to reduce patient exposure dose, and adjusting the fluoflavor was a good alternative method for reducing patient exposure dose at high fps. Therefore the method of condition change with the greatest dose reduction effect is to set the minimum FPS and can reduce patient exposure dose according to geometric conditions and fluoflavor characteristics.

• Journal of the Korean Society of Radiology
• /
• v.11 no.6
• /
• pp.453-458
• /
• 2017

Computed Tomography (CT) provides information on the Diagnostic Reference Level Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) for accurate diagnosis of patients. However, it does not provide a dose change according to the table height for the diagnostic reference level provided by the CT equipment. The purpose of this study was to evaluate the image and dose according to the table height change using phantom (PMMA: Polymethyl Methacrylate) in order to find the optimal image and the minimum dose during computed tomography examination. When examining using a 32 cm PMMA phantom with the same thickness as the abdomen of an adult, there was little change in dose with table height. However, the noise evaluation of the image caused a high fluctuation of noise depending on the table height. and in the case of the 16 cm PMMA phantom, the change of the noise was small, but the dose change was about 30%. In conclusion, the location of the patient and the center of the detector are important during computed tomography (CT) examinations. In addition, table height setting is considered to be important for examinations with optimized image and minimum dose.

• Journal of Radiation Protection and Research
• /
• v.26 no.3
• /
• pp.183-190
• /
• 2001

The activity concentration of primordial radionuclides i.e., $^{238}U$ series, $^{232}Th$ series and $^{40}K$, in soil samples collected from Udagamandalam environment, have been measured by employing NaI (Tl) Gamma ray Spectrometer. The absorbed gamma dose rate has also been simultaneously measured by using both Environmental Radiation Dosimeter at each soil sampling location (ambient gamma dose) as well as from the gamma dose derived from the activity concentration of the primordial radionuclides. The results of activity concentration of each radio nuclides in soil, absorbed dose rate in air due to soil activity and possible cosmic radiation at each location along with human effective dose equivalent for Udagamandalam environment are presented and discussed.

• Journal of radiological science and technology
• /
• v.43 no.6
• /
• pp.469-473
• /
• 2020

Breast cancer is growing rapidly year by year and has the highest incidence since 2001. As a result, the interest in mammography for early detection of breast cancer is increasing. However, mammography is accompanied by radiation exposure and therefore it is necessary to reduce exposure dose through appropriate test conditions. The significance of this study is that breast dose studies, which were limited to ordinary women, were applied to breast implant patient. Using MCNP simulation, the phantom with prosthesis inserted was developed to compare dose by tube voltage by pressure thickness. In addition phantom without prostheses has higher dose than phantom with prostheses. If these results were used as basic data, it would be possible to recommend test condition guideline only for breast implant patients.

• Nuclear Engineering and Technology
• /
• v.55 no.1
• /
• pp.254-260
• /
• 2023

Skeletal metastases are common in patients suffering from various primary cancers. Radiopharmaceuticals are an effective option for bone pain palliation. In this work, the radiation absorbed dose of ¹⁷⁷Lu-EDTMP radiopharmaceutical was estimated for adult man based on biodistribution data in Wistar rats. The MIRD dose calculation method and the Sparks and Aydogan methodology were applied. The results shows that about 46% of injected activity is cumulated on the surface of the trabecular and cortical bones. Radiation absorbed doses of red bone marrow and osteogenic cells were estimated to about 1.1 and 6.2 mGy/MBq, respectively. The maximum administrated activity was obtained 27 MBq/kg of body weight with an effective dose of 0.23 mSv/MBq. The results were compared with other available data from literature. This study indicated that ¹⁷⁷Lu-EDTMP provides therapeutic efficacy for achieving bone pain palliation with low undesired dose to other normal organs.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.4
• /
• pp.508-516
• /
• 2019

Objectives: The present study was performed to obtain acute toxicity information on glyoxal in male rats after intratracheal instillation. Methods: In order to calculate the LD₅₀ of glyoxal using Probit analysis with SAS, the test article was one intratracheal instillation to male Sprague-Dawley rats at dose levels of 0, 225, 451 or 902 mg/kg. During the test period, mortality, clinical signs, and body and organ weights were examined. At the end of the 14-day observation period, all animals were sacrificed and complete gross postmortem and histopathological examinations were performed. Results: Four animals of the 902 mg/kg group died within one week after the administration of glyoxal. All treatment group in a dose dependent manner, decreased body weight was found during the study period. The absolute and relative lung weight, and histopathological changes (bronchiolar-alveolar hyperplasia, chronic inflammation) of lung exhibited an increased in glyoxal treated groups in a dose dependent manner. However, there were no changes on the organ weights and histopathological changes of any other organ except lung. Conclusions: The results obtained in the present study suggest that the LD₅₀ in male Sprague-Dawley rats after a single intratracheal instillation of glyoxal was considered to be 866.9 mg/kg and the lung was found to be the target organ for glyoxal.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.27 no.1
• /
• pp.79-90
• /
• 2014

Objectives : This study was carried out to evaluate the repeated dose oral toxicity of Alismatis Rhizoma in Sprague-Dawley(SD) rats. Methods : Male and female rats were administered orally with Alismatis Rhizoma water extract of 500 mg/kg(low dosage group), 1,000 mg/kg(middle dosage group) and 2,000 mg/kg(high dosage group). We daily observed number of deaths, clinical signs and gross findings for 14 days(twice a day). After 14 days, we measured body and organs weight. Also we analyzed hematological changes. Results : No dead SD rats and no clinical signs were found during the experiment period. Also other specific changes were not found between control and treated groups in hematology and serum biochemistry. In addition no significant changes of gross body and individual organs weight. Conclusions : These results suggest that water soluble extract of Alismatis Rhizoma has not repeated dose oral toxicity and oral LD50 value was over 2,000 mg/kg in SD rats. As a result, we can determine Alismatis Rhizoma is a relatively safe substance.