• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1781-1788
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• 2022

The containment building Kori Unit 1 may require sequential steps for full decommissioning. This study assumes that the containment building is to be used as an auxiliary building that handles nuclear power systems and materials during decommissioning before conversion into a greenfield. Through the derivation of guidelines and dose evaluation, it was confirmed whether the radiation workers were satisfied with the ALARA decision. The specific modeling of the external radiation exposure was performed based on the facility investigation procedures. The external radiation specific derived concentration guideline levels (DCGLs) for radiation workers in containment building were obtained using the RESRAD-BUILD code and were applied to the VISIPLAN 3D ALARA Planning Tool code to calculate the working dose and check worker safety. The derivation of site-specific and realistic DCGLs and dose evaluation via 3D modeling can contribute to the scenario development for the decommission and remediation of containment building.

• 한국콘텐츠학회논문지
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• 제17권7호
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• pp.498-504
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• 2017

치아를 칫솔질하거나 치약을 사용하는 것과 같은 구강 건강 행위는 구강 건강을 개선하며, 따라서 삶의 질을 향상시키는 중요한 부분이다. 그러나 화학 물질에 대한 연구도 필요한 실정이다. 따라서 본 연구는 구강 건강 행위로 인해 야기되어지는 불소 노출에 미치는 요인을 조사하여 정확한 구강 건강 지침을 제공하고자 한다. ConsExpo 5.0 모델에서 불소 화합물의 경구 노출을 적용한 결과, 일일 불소 인체노출량 추정은 성인남성의 모델 결과 oral external dose는 0.000196 mg/kg, oral acute(internal) dose는 0.000196 mg/kg, oral chronic(internal)dose는 0.000465 mg/kg/day로 추정되었다. 성인여성은 연구결과 oral external dose는 $4.1{\times}10^{-6}mg/kg$, oral acute(internal) dose $4.1{\times}10^{-6}mg/kg$, oral chronic(internal) dose $9.99{\times}10^{-6}mg/kg/day$로 추정되었다.

• 자원환경지질
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• 제32권3호
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• pp.273-280
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• 1999

In order to protect inhabitans' health and to collect data for prediction of the effcts from accidental emission of rasioactive materials from nuclear power plant, exposed dose rate be monitored within the limit dose rate. This research was carried out to investigate the accumulation of environmental radioactivity around Younggwang Nuclear Power Plant, and to infer and in infer and assay the additional exposed dose rate of inhabitants in Younggwang site from the operation of nuclear plant operation. External radiation dose rate, radiation environmental samples, and exposed dose rate of inhabitants in Younggwang site were investigated for estimaing environment activity in the vicinity of the nuclear power plant area. For the external radiation dose rate, the result showed that range of normal variation was found and any artificial radioisotope was not deteted in the analysis of environmental samples. Exposed dose rate of inhabitants was lower than 0.4% of the limit value of ICRP and it may be concluded that there was no effect on inhabitants and environment from the operation of nuclear power plant.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.302-304
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• 2002

In linac-based stereotactic radiosurgery, assuring the quality of the planning and delivery of external photon beam requires accurate evaluation of beam parameters, usually including output factors, tissue-phantom ratio and off-axis ratios, and measurement of actual dose distributions from simulated treatment. We're going to test the use of calibrated radio chromic film (Gafchromic film; type MD-55, Nuclear associate) using a Lumiscan 75 digitizer to measure absolute dose and relative dose distributions for linac-based radiosurgery unit Relative dose distribution of a human-style spherical acryl phantom were measured using radiochromic film and calculated by treatment planning system. The absolute dose at the sphere center was measured by radiochromic film and micro chamber (Exradin A-14, 0.009cc). What we want to demonstrate in this work, the 'well selected' radiochromic films when external photon beam are used in linac-based stereotactic radiosurgery are very accurate detector for dosimetry.

• Radiation Oncology Journal
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• 제14권3호
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• pp.201-209
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• 1996

목적 : FIGO 병기 Ib 자궁경부편평상피암 환자에서 고선량율 강내치료를 이용한 방사선치료후 환해율, 5년 국소제어을, 5년 생존율 및 예후인자, 방사선 합병증을 분석하여 고선량율 강내치료의 효용성을 평가하고자 하였다. 그리고 심각한 후기 합병증 없이 만족스런 국소 제어율을 얻기 위한 외부방사선선량과 강내치료선량의 최적 선량배합을 알아보고자 하였다. 대상 및 방법 : 1979. 5 - 1990. 12월 까지 연세암센타 치료방사선과에서 자궁경부 편평상피암 FlGO 병기 Ib로 진단된후 근치적 목적하에 외부 및 강내치료를 받은 162명의 환자들을 대상으로 치료 결과를 후향적 분석하였다. 외부 방사선 치료는 LINAC 10MV X-ray를 이용해 180-200cGy/fr씩 4000-4600cGy14.5-5주를 전골반 부위에 시행하였근데, 일부환자에서 2000-4000 cGy에서 중앙차폐(midline block)를 시행하였다. 코발트 선원을 이용한 원격 조정 아프터 로딩 고선량율 강내치료를 A점에 1회당 300cGy씩 주 3회, 총 10-13회 (3000-3900 cGy)실시하여 A 점에 들어간 총방사선 조사량은 6420 - 9500cGy 으로 평균 8394 cGy 였다. 결과 : 방사선 치료후 완전 관해율은 $99.4\%$ 였다. 5년 전체생존율은 $91.1\%$이고, 5년 무병생존율은 $90.9\%$였다. 추적 관찰 기간동안 치료 실패 양상을 관찰해 보면 국소 실패만 보인 경우는 7명이었고 원격전이만 보인경우가 6명이었으며, 국소 및 원격전이가 모두 발생한 경우가 1예 있어서 국소제어 실괘율은 $4.9\%$(8/163), 원격전이율은 $4.3\%$(7/164)였다. 후기 합병증은 38명 ($23.5\%$)에서 발생하였초, 그 중 30병 직장 합병증으로 $18.5\%$ 후기 합병증 발생율을 보였고, 방광 합병증은 8명에서 발생하여 $4.9\%$ 후기 합병증 발생율을 보였다. 직장 합병증이 생긴 환자관에서 직장에 소사된 방사선량은 평균 7887 cGy 이었고, 합병증이 발생하지 않은 환자군의 평균조사량은 7488 cGy이었다. 결론 : 근치적 목적으로 외부 방사선 치료 및 고선량률 강내 치료는 FIGO병기 Ib 자궁경 부편평상피암을 치료하는데 매우 효과석이라 생각하였고, 외부방사선치료중 중앙차폐를 시행하여 A점 선량이 75Gy를 넘지 않게 방사선치료 설계를 하면 심각 합병증없이 좋은 치료성적을 얻을 수 있겠다.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.273-281
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• 2021

The radiological safety of the spent resin treatment facility with a¹⁴C treatment capacity of 1 ton/day was evaluated in terms of the external and internal exposure of worker according to operation scenario. In terms of external dose, the annual dose for close work for 1 h/day at a distance of more than 1 m (19.8 mSv) satisfied the annual dose limit. For 8 h of close work per day, the annual dose exceeded the dose limit. For remote work of 2000 h/year, the annual dose was 14.4 mSv. Lead shielding was considered to reduce exposure dose, and the highest annual dose during close work for 1 h/day corresponded to 6.75 mSv. For close work of 2000 h/year and lead thickness exceeding 1.5 cm, the highest value of annual dose was derived as 13.2 mSv. In terms of internal exposure, the initial year dose was estimated to be 1.14E+03 mSv when conservatively 100% of the nuclides were assumed to leak. The allowable outflow rate was derived as 7.77E-02% and 2.00E-01% for the average limit of 20 mSv and the maximum limit of 50 mSv, respectively, where the annual replacement of the worker was required for 50 mSv.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2003년도 제27회 추계학술대회
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• pp.71-71
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• 2003

The study on magnetic field combined radiation therapy, as a new technique to modify the dose distributions using external magnetic field, has been investigated. The goal of the study is to develop the techniques for dose localization, as a particle beam, from the strong magnetic fields. In this study, in order to study the principle of dose deposition in external fields, as a basic approach, we have calculated approximately the paths of traveling electrons in water under external magnetic fields with numerical methods. The calculations are performed for a primary particle by cumulating the steps which are defined as small path lengths which energy loss can be ignored. In this calculation, the energy loss and direction change for a step was calculated by using total stopping power and Lorentz force equation respectively. We have examined the deflected paths of the electron through water as a function of external magnetic field and incident electron s energy. Since we did not take account of the multiple scattering effects for electrons through water, there are errors in this calculation. However, from the results we can explain the principle of dose variation and dose focusing for electron beams under strong magnetic fields in water.

• Radiation Oncology Journal
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• 제14권1호
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• pp.41-52
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• 1996

목적 : 외부 방사선 치료(External Radiation Therapy) 및 Gamma-med (Iridium-192) 고선량 강내 방사선 치료를 받은 자궁 경부암 FIGO stage IIB 환자에서 직장 합병증 발생률 및 이와 관계있는 인자를 후향적으로 분석해 보았다. 대상 및 방법 : 1989년 11월부터 1992년 12월까지 연세암센터 치료방사선과에서 근치적 목적의 외부 및 강내 방사선치료를 받은 FIGO 병기 IIB 자궁경부암 환자 88명을 대상으로 방사선치료후 발생한 직장 합병증 및 이와 연관된 인자들을 분석하여 보았다. 환자들의 연령은 29-83세로 평균치, 중앙치 모두 57세였고 병리조직 분류상 편평상피세포암이 84예 선암이 4예였다. 방사선치료는 외부방사선을 골반 부위에 5-6주 동안 4500-5400cGy 치료하였으며 환자별로 중간 차폐를 시행하였고 고선량 Gamma-med ICR은 A점에 1회당 500cGy씩 1주 2회로 총 3000cGy 조사하였다. 외부 방사선치료시 중앙 차폐까지의 외부 조사량, ICR rectal dose(r) 및 total rectal dose(R), ICRU 38에 따른 ICR rectal dose(Dr)와 total Dr dose(OR), ICR reference volume, TDF, BED(Biologically Effective Dose)를 계산하고 분석해 합병증과의 연관성을 찾아보았다. 대상 환자 88명중 87명($98.9\%$)에서 최저 24개월 이상 추적 관찰이 가능하였으며 중앙치는 40개월(20-66개월)이었다. 결과 : 직장 합병증은 27예에서 발생하였는데($30.7\%$) grade 1이 12예($13.6\%$), 2가 12예($13.6\%$), 3이 3($3.4\%$)예였고 합병증이 발생하는 시기는 망사선치료후 4-43개월(중앙치 16개월, 평균 17.3개월)이었다. 직장 합병증이 발생하지 않은 환자군의 total rectal dose(R)는 $6772.67{\pm}884.02$로 grade 2-3 합병증이 발생한 15명의 R=$7163.0{\pm}838.49$와 유의한 차이를 보였으며 total Dr dose (DR)도 두 군간에 차이를 보였다 또 grade 2-3인 직장 합병증 발생률은 중앙 차폐시 까지의 외부 방사선량과 관계가 있었는데 36Gy이하에서는 $10\%$, 36-40Gy는 $21.4\%$, 40Gy 이상에서는 $29.3\%$의 직장 합병증이 발생하여 중앙 차폐까지 조사된 외부 방사선량이 증가할수록 직장 합병증이 증가함을 알 수 있었다. 직장에 조사된 총직장 조사량(R)에 따라 grade 2-3 합병증 발생률이 증가하였는데 65Gy 이하에서는 $10.5\%$, 65-75Gy는 $17.2\%$, 75Gy이상 조사된 환자군에서는 $28.5\%$로 조사량이 증가할수록 직장 합병증이 증가하는 알상이었으며 ICRU 38 에 따른 total rectal dose (DR)에 대해서도 비슷한 양상이었다. ICR rectal dose(r, Dr)만 따로 분석해 보았는데 방사선량과 직장 합병증간에는 차이가 없었다. 그 외의 인자로 분석한 TDF 와 BED도 grade 2-3의 경우에는 그 값이 증가할수록 증가하는 양상을 보였으나 통계적인 유의성은 없었고 Gamma Dot 에서 계산되는 ICR reference volume도 분석해 보았으나 합병증파의 연관성을 발견할 수 없었다. 결론 : 병기 IIB 자궁경부암 환자에서 외부 방사선치료 및 고선량 강내 방사선치료후 직장 합병증 발생률은 $30.7\%$(grade 2-3: 15예 $17\%$)였다. 직장 합병증 발생에 영향을 미치는 중요한 인자는 직장에 조사된 전골반 방사선량(중앙 차폐까지의 방사선량) 및 고선량 강내 방사선 치료와 합한 총직장 방사선량(r, Dr)으로 나타났으며 이들이 증가할수록 합병증 발생률이 증가하였다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1225-1233
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• 2024

Level 3 probabilistic safety assessment (PSA) is performed to calculate radionuclide concentrations and exposure dose resulting from nuclear power plant accidents. To calculate the external exposure dose from the released radioactive materials, the radionuclide concentrations are multiplied by two factors of dose coefficient and a finite cloud dose correction factor (FCDCF), and the obtained values are summed. This indicates that a standard set of FCDCFs is required for external exposure dose calculations. To calculate a standard set of FCDCFs, the effective distance from the release point to the receptor along the wind direction should be predetermined. The TID-24190 document published in 1968 provides equations to calculate FCDCFs and the resultant standard set of FCDCFs. However, it does not provide any explanation on the effective distance required to calculate the standard set of FCDCFs. In 2021, Sandia National Laboratories (SNLs) proposed a method to predetermine finite effective distances depending on the atmospheric stability classes A to F, which results in six standard sets of FCDCFs. Meanwhile, independently of the SNLs, the authors of this paper discovered that an infinite effective distance assumption is a very reasonable approach to calculate one standard set of FCDCFs, and they implemented it into the multi-unit radiological consequence calculator (MURCC) code, which is a post-processor of the level 3 PSA codes. This paper calculates and compares short- and long-range FCDCFs calculated using the TID-24190, SNLs method, and MURCC method, and explains the strength of the MURCC method over the SNLs method. Although six standard sets of FCDCFs are required by the SNLs method, one standard sets of FCDCFs are sufficient by the MURCC method. Additionally, the use of the MURCC method and its resultant FCDCFs for level 3 PSA was strongly recommended.

• Radiation Oncology Journal
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• 제2권2호
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• pp.261-270
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• 1984

The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiation and medical records of 203 patients who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analized. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem applicator to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids were measured for low dose rate irradiation system and high dose rate remote control afterloading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results ; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as $4\~7cm$ width and high dose rate system showed as $5\~6cm$. 2. In horizontal angulation of tandem to body axis, the low dose rate system revealed mid position$64.6\%$, left deviation $19.2\%$and right deviation $16.2\%$. 3. In longitudinal angulation of tandem to body axis, the mid position was $11.8\%$ and anterior angulation $88.2\%$ in low dose rate system but in high dose rate system, anterior angulation was $98.5\%$. 4. Down ward displacement of ovoids below external os was only $3\%$ in low dose rate system and $66.7\%$ in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses an4 TDF were 50, 70 Gy and 141, 123, including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 93, 47 Gy and 230, 73 in high dose rate system but in low doss rate system, 123, 52 Gy and 262, 75 respectively. 8. Doses and TDF in bladder and rectum were 70, 68 Gy and 124, 120 in low dose rate system, but in high dose rate system, 58, 64 Gy 98, 110 respectively, and then grades of injuries in bladder and rectum were 25, $30\%$ and 18, $23\%$ respectively.