• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.217-233
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• 2014

Securing the radiological safety is a prerequisite for the safe management of the naturally occurring radioactive materials (NORM) which cannot be reused. This becomes a crucial focus of our R&D efforts upon the implementation of the Act on Protective Action Guidelines against Radiation in the Natural Environment. To secure the safety, the establishment of technical bases and procedures for securing radiological safety related to the disposal of NORM is required. Thus, it is necessary to analyze the characteristics, to collect the data, to have the radiological safety assessment methodologies and tools, to investigate disposal methods and facilities, and to study the effects of the input data on the safety for the NORM wastes. Here, we assess the environmental impact of the NORM waste disposal with respect to the major domestic and foreign NORM characteristics. The data associated with major industries are collected/analyzed and the status of disposal facilities and methodologies relevant to the NORM wastes is investigated. We also suggest the conceptual design concept of a landfill disposal facility and the management plan with respect to the major NORM wastes characteristics. The radionuclide pathways are identified for the atmospheric transport and leachate release and the environmental impact assessment methodology for the NORM waste disposal is established using a relevant code. The assessment and analysis on the exposure doses and excessive cancer risks for the NORM waste disposal are performed using the characteristics of the representative domestic NORM wastes including flying ash, phosphor gypsum, and redmud. The results show that the exposure dose and the excessive cancer risks are very low to consider any radiation effects. This study will contribute to development in the areas of the regulatory technology for securing radiological safety relevant to NORM waste disposal and to the implementation technology for the Act.

• Journal of radiological science and technology
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• v.31 no.1
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• pp.11-16
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• 2008

Purpose : The aim of this study was to predict radiation dose at 1 meter with BMI(body mass index) in thyroid cancer patients treated with radio-iodine and provide the efficient guideline in the management of patients. Methods : 140 patients from thyroidectomy for thyroid cancer were enrolled. All subjects under went 150 mCi radio-iodine therapy and performed whole body scan 1 week later. BMI(weight divided by square of height) was calculated to evaluate the amount of fatty tissue indirectly. The radiation dose at 1 meter was measured initially and on 2nd days. the relation of values with BMI were analyzed statically. As for the method of statistical analysis, using Med calc Version 9,2,2,0 Program. Results : (1) The initial effective dose was inversely correlated with the BMI. Significance level was 0.0004. (2) We obtained the following formula from the data of initial effective dose and BMI: Y = -30.91X + 350.4(${\mu}Sv/h$)(Y: initial radiation dose, x: Group). (3) After 21.55 hours, than radiation dose was less than those recommended by ICRP or NRC in 53% of the population. Conclusion : Using BMI, the initial radiation dose and 2nd days dose can be predicted in thyroid cancer patients before radio-iodine therapy. It may be used for predicting the time of discharge and control the isolation room. We were able to predict the radiation exposure after discharge using this calculated value.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.91-98
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• 2008

Purpose: Radio-isotopes (RI) use has been steadily developing due to industrial and technical development in the modern medical society. Particularly, popularization of domestic cyclotrons dramatically enable hospitals to produce and use diagnostic radio-isotopes. Generally, only specific facilities such as hospitals, research institutes, nuclear power plants and universities can use radio-isotopes, they are also responsible for ventilation system. The strength of radioactivity in the air is strongly regulated and controlled by korea atomic energy law in Korea Institue of Nuclear Safety (KINS), so that air radioactivity exposure can lead to environmental pollution surrounding places. In this study, we'd like to find out the investigation and the present condition of the controlled ventilation system in domestic hospitals by an emission standard from KINS, and try to reach an agreement about how to use the ventilation system. Result: Definition of filters, features and structures of pre-filters, hepa-filters, charcol filters, filter exchange procedures and precautions are explained. RI deflation concentration and filter exchange cycle have been presented as a standard prescribed in the rules of KINS. The Radiation Control Management System (RCMS) introduced by Seoul National University Bundang Hospital linking to digital pressure gauge with computer controller in another medical facilities were described in details. Conclusions: The system of medical facilities using RI has been remarkably developing in 21 century. Especially, radiation safety control system has also been grown rapidly into the subdivision, specialization, advanced technology along with international technical improvement. However, As far as current RI ventilation system is concerned, it has nothing better than doing in the past. Preferentially, to reinforce this, more sophisticated system with strict periodic filter exchange and exhaust air control guidance should be introduced by applying brilliant domestic information technology for RCMS and digital gauge method. From personal point of view as a radiation safety manager, I have provide with present problems and improvements. Futhermore, more improved guidance should be conducted.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.53-57
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• 2010

This study proposes the algorithm which drives the powerless without battery. The exiting wire or RF type dosimeter, which is the computation of the real time with battery on the dose radiation exposure, In the Wired dosimeter, it is trouble to need the maintenance and management by periods. Besides, the case of the RF typed dosimeter with battery, it is requested to size bigger and to replace battery frequently and so on. Especially RF typed dosimeter has trouble to need for the embody with large power consumption on the contactless typed dosimeter. As the method for the low power, the study designed to be down the operating clock of the MPC, to improve the efficiency of the rectifier, to eliminate the external memory and the DC-DC converter for the simplification of the circuit We convince our research contributes not only to understand the simplified circuit and miniaturization, but also to help the design and application technology of the powerless dosimeter.

• Archives of Reconstructive Microsurgery
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• v.7 no.2
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• pp.114-121
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• 1998

The purpose of this study is to investigate the appropriate management of severe radionecrotic wounds of the anterior chest wall associated with infection of the soft tissues and ribs and exposure of vital structures(heart and lung), and present our strategies for reconstruction of these complicated patients. 9 patients have undergone radical debridement and immediate microsurgical reconstruction for severe radionecrotic wounds of the anterior chest wall over last 7 years. All patients had extensive osteomyelitis of the ribs or sternum, and chronic infection or cutaneous fistulae. 2 patients had pericardial effusions due to longstanding inflammation, and 6 patients had pleural effusions. 2 patients had ipsilateral lung collapse. 10 free flaps were performed for coverage of the huge defects. One patient required 2 free flaps to control the inflammation. 8 free TRAM flaps were used for coverage of the defects and in addition, the rectus abdominis muscle was packed into any deep cavity. 1 patients underwent latissimus dorsi muscle free flap because of previous abdominal surgery. After extensive debridement of the infected, radionecrotic wounds, all 10 free flaps were successful. All the extensive radionecrotic defects of the anterior chest wall were completely healed. Free flaps successfully covered the exposed vital structures of the heart and lungs. Patients with severe radionecrotic defects of the anterior chest wall after ablative breast cancer surgery and radiotherapy were successfully treated by radical debridement and immediate free flap surgery. The TRAM flap together with the rectus muscle is the treatment of choice for these huge defects. The latissimus dorsi muscle flap was the second choice in patients with previous abdominal surgery. The recipient vessel should be carefully selected because of possible radiation damage and inflammation.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.428-431
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• 2009

Purpose: Blow out fracture resulting from facial trauma is of high frequency among facial bone fractures, and can cause severe complications. So, proper management and close observation after operation are needed. So far, Computed tomography has been the best choice in the evalution following orbit wall reconstruction. However, cost - effectiveness, accessibility to patients and hazard of radiation exposure of computed tomography require supplementary measure for the evaluation following orbit wall reconstruction. This study was performed to describe the effectiveness of ultrasonography in the evalution following orbit wall reconstruction. Methods: A retrospective study was performed on 40 patients who underwent orbit wall reconstruction from June, 2008 to July, 2008. The patients' ages ranged from 13 to 65 years (mean 27.5 years), and this group was compsoed of 27 male and 13 female patients. The follow up period ranged from 2 weeks to 28 weeks (mean 11weeks). Preoperatively, all fractures were diagnosed using computed tomography. Ultrasonography for all cases, and computed tomography for 2 cases were performed for evaluation following orbit wall reconstruction. Results: Reduction of herniated orbital soft tissue and orbit implant was identified by using ultrasonography in 38 cases out of 40 cases. In other cases which we could not identify the orbit implant, computed tomography was performed. Con clusion: Compared to computed tomography, ultrasonography is simple, inexpensive and convenient method. Ultrasonography can be used as supplementary measure to computed tomography in the evaluation following orbit wall reconstruction for elective patients.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.322-327
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• 2003

It is important to know the accurate radionuclide inventory of radioactive waste for the reliable management. However, estimation of radionuclide concentrations in drummed radioactive waste is difficult and unreliable because of difficulties of direct detection, high cost, and radiation exposure of sampling personnel. In order to overcome these difficulties, scaling factors (SFs) have been used to assess the activities of radionuclides that could not be directly analyzed. A radionuclide assay system has been operated at KORI site since 1996 and consolidated scaling factor method has played a dominant role in determination of radionuclides concentrations. However, some problems are still remained such as uncertainty of estimated scaling factor values, inaccuracy of analyzed sample values, and disparity between the actual and ideal correlation pairs and the others. Therefore, it needs to improve the accuracy of scaling factor values. The scope of this paper is focused on the improvement of accuracy and representativeness of calculated scaling factor values based on statistical techniques. For the selection of reliable activity determination method, the accuracy of estimated SF values for each activity determination method is compared. From the comparison of each activity determination methods, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.441-447
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• 2018

This study aims to develop digital techniques that enable repeated practice of dental radiography using augmented reality technology. A three-dimensional object was fabricated by superimposing a photograph of an adult model and a computed tomography image of a manikin phantom. The system was structured using 106 radiographs such that one of these saved radiographs is opened when the user attempts to take a radiograph on a mobile device. This system enabled users to repeatedly practice at the pre-clinical stage without exposure to radiation. We attempt to contribute to enhancing dental hygienists' competency in dental radiography using these techniques. However, a system that enables the user to actually take a radiograph based on face recognition would be more useful in terms of practice, so additional studies are needed on the topic.

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.2
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• pp.13-18
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• 2013

Purpose : Fluoroscopy equipment, depending on the type of changes that occur in the patient's position ESD and study the patient's scatter ray of ESD Practitioners considered a comparative analysis was to evaluate the correct dose. Materials and Methods : HITACHI four overtube type TU-8000 Flat Detector and Under tube C-Arm Philips' Multi Diagnost Eleva with Flat Detector type were measured by. Each devices is a measure of the patient's esd randophantom position in tabel unfors Xi multi funtion then fixed to the abdomen fluoroscopy and 10 seconds, spot was measured three times, practitioners of the incident surface dose by considering the patient's scatter ray of the table for each device in the average human stomach 21cm thickness acrylic phantom ($25cm{\times}25cm$) Place the practitioner position after position randophantom unfors Xi multi funtion in the thyroid and stomach 1 minute by a fixed one-time fluoroscopy and measured. Results : 10 seconds and the patient perspective of the c-arm ESD 1.2 times smaller on the AP and oblique measurements were measured in the 6-13 times smaller. spot positions to changes in the measured three times on the AP of the abdomen, ESD is 18 times smaller c-arm measurements and the oblique measurement was 19-30 times smaller. And 1 minute at practitioners fluoroscopy esd in the thyroid 2.12 times the c-arm, chest 1.75 times less the dose was measured. On the AP, depending on the device, but the lack of dose difference oblique positions of the two devices depending on changes in the area due to changes in both the AP than on the dose increased, the difference in dose between the two devices, the maximum difference was approximately 27 times. Conclusion : Fluoroscopic equipment at the time of inspection in accordance with changes in dose according to the patient and the patient's positions changes, because the area of the scatter ray considering the change of dose measurements be made, and study of the equipment according to the characteristics of the efficiency and the exposure of the patient and practitioner is considered smooth study equipment manufacturers that can be done is to build the system and think that is also important. Various fluoroscopy when you check future changes in many factors of change in dose for the equipment in the laboratory system by considering the scatter ray radiation shielding for the management to take advantage of reckless undertube have been utilized as more exposure Reduction activities can help is considered as the direction.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3465-3468
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• 2016

Background: Fluorodeoxyglucose ($^{18}FDG$) PET/CT imaging has become an important component of the management paradigm in oncology. However, the significant imparted radiation exposure is a matter of growing concern especially in younger populations who have better odds of survival. The aim of this study was to estimate the effective dose received by patients having whole body $^{18}F$-FDG PET/CT scanning as per recent dose reducing guidelines at a tertiary care hospital. Materials and Methods: This prospective study covered 63 patients with different cancers who were referred for PET/CT study for various indications. Patients were prepared as per departmental protocol and 18FDG was injected at 3 MBq/Kg and a low dose, non-enhanced CT protocol (LD-NECT) was used. Diagnostic CT studies of specific regions were subsequently performed if required. Effective dose imparted by 18FDG (internal exposure) was calculated by using multiplying injected dose in MBq with coefficient $1.9{\times}10^{-2}mSv/MBq$ according to ICRP publication 106. Effective dose imparted by CT was calculated by multiplying DLP (mGy.cm) with ICRP conversion coefficient "k" 0.015 [mSv / (mG. cm)]. Results: Mean age of patients was $49{\pm}18$ years with a male to female ratio of 35:28 (56%:44%). Median dose of 18FDG given was 194 MBq (range: 139-293). Median CTDIvol was 3.25 (2.4-6.2) and median DLP was 334.95 (246.70 - 576.70). Estimated median effective dose imparted by $^{18}FDG$ was 3.69 mSv (range: 2.85-5.57). Similarly the estimated median effective dose by low dose (non-diagnostic) CT examination was 4.93 mSv (range: 2.14 -10.49). Median total effective dose by whole body 18FDG PET plus low dose non-diagnostic CT study was 8.85 mSv (range: 5.56-13.00). Conclusions: We conclude that the median effective dose from a whole body 18FDG PET/CT in our patients was significantly low. We suggest adhering to recently published dose reducing strategies, use of ToF scanner with CT dose reducing option to achieve the lower if not the lowest effective dose. This would certainly reduce the risk of second primary malignancy in younger patients with higher odds of cure from first primary cancer.