• Journal of Radiation Protection and Research
• /
• 제41권3호
• /
• pp.301-309
• /
• 2016

Background: A contamination screening process for the local population in radiation emergencies is discussed. Materials and Methods: We present an overview of the relevant Korean governmental regulations that underpin the development of an effective response system. Moreover, case studies of foreign countries responding to mass casualties are presented, and indicate that responses should be able to handle a large demand for contamination screening of the local public as well as screening of the immediate victims of the incident. Results and Discussion: We propose operating procedures for an off-site contamination screening post operated by the local government for members of the public who have not been directly harmed in the accident. In order to devise screening categories, sorting strategies assessing contamination and exposure are discussed, as well as a psychological response system. Conclusion: This study will lead to the effective operation of contamination screening clinics if an accident occurs. Furthermore, the role of contamination screening clinics in the overall context of the radiation emergency treatment system should be clearly established.

• 방사선산업학회지
• /
• 제5권2호
• /
• pp.185-189
• /
• 2011

As nuclear industry has been developed, a various types of radiological contamination has occurred. After 9.11 terror in U.S.A., it has been concerned that terrorists' active area has been enlarged to use nuclear or radioactive substance. Recently, the most powerful earth-quake stroke, which triggered a massive tsunami in Japan and then Fukushima nuclear power plant reactor has suffered from a serious accident in history. The Fukushima reactor accident has occurred an anxiety of radiation leaks and about 170,000 people have been evacuated from the accidental area near the nuclear power plant. For these reasons, a social chaos can be occurred if radiological contamination occurs to the supply system for the drinking water. As such, the establishment of the radiation monitoring system for the city main water system is compelling for the national security. In this study, a feasibility test of radiation monitoring system which consists of unified hybrid-type radiation detectors was experimented for multi detection system by using gamma-ray imaging. The hybrid-type radiation sensors were fabricated with CsI(Tl) scintillators and photodiodes. A preamplifier and amplifier was also fabricated and assembled with the sensor in the shielding case. For the preliminary test of detection of radiological contamination in the river, multi CsI(Tl)-PIN photodiode radiation detectors and $^{137}Cs$ gamma-ray source were used. The DAQ was done by Linux based ROOT program and NI DAQ system with Labview program. The simulated contamination was assumed to be occurred at Gapcheon river in Daejeon city. Multi CsI(Tl)-PIN photodiode radiation detectors were positioned at the Gapcheon river side. Assuming that the radiological contaminations flows in the river the $^{137}Cs$ gamma-ray source has been moved and then, the contamination region was reconstructed.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권1호
• /
• pp.1-7
• /
• 2020

In this study, the contamination level was measured using an ATP meter using adenosine triphosphate bioluminescent material to find effective infection control to compensate for the disadvantages of the microbial culture method used for hygiene control of ultrasound probe. The convex probes were selected from six ultrasound probe in the hospital, and the samples were taken in real time before and after cleaning to check the contamination of the probe. In order to classify the pollution degree using the APT meter was classified by category. A total of 78 samples were collected from the ultrasound probe. When the pollution levels before and after cleaning were classified by category, 76.6% of the samples were classified into category 3·4 before cleaning, but they decreased to 23.3% after cleaning. 13.3% before cleaning was in category 1, but increased to 43.3% after cleaning. By classifying the pollution level, it was confirmed that the pollution level was significantly reduced by category. Until now, there was no suitable criterion for determining the contamination level by using ATP meter in medical machines where sample area is small and reused. In this study, criteria for each category were set to measure the contamination level of ATP meter suitable for small sample area such as ultrasound probe, so that contamination level could be determined in real time at the site. Therefore, it is considered that hygiene management for ultrasound probe can be more actively performed.

• 한국융합학회논문지
• /
• 제11권1호
• /
• pp.51-56
• /
• 2020

본 연구는 강원도 지역 K 대학교내 방사선촬영 실습실의 진단용 엑스선 발생장치 1대를 선택하여 table, IP cassette, 의료방사선 차폐용 납 가운의 표면 오염도의 세균을 검출하여 적절한 소독관리와 학생들의 손 위생의 필요성을 알리고자 한다. 그 후 휴지, tissue cleaner, 70% alchol로 소독을 실시하고 즉시 멸균면봉으로 채취하여 표면의 오염 분포상태 및 소독효과를 평가하였다. 표면의 오염 분포도를 측정한 결과는 Apron에서 가장 많은 균이 검출되었고 표면 오염도에 따른 소독효과 평가는 IP cassette에서는 70% Alcohol에서 두드러진 효과가 나타나고 Apron와 Table의 경우는 Tissue cleaner, 70% Alcohol에서는 소독효과가 동일함을 확인하였다. 따라서 학생들 사이에서 세균 감염을 방지하기 위하여 실습 전에 기본적인 손 씻기, 주기적인 소독을 하여 감염을 방지하여야 한다.

• 한국의학물리학회지:의학물리
• /
• 제27권3호
• /
• pp.146-155
• /
• 2016

As the probability of exposure to radiation increases due to an increase in the use of radioisotopes and radiation generators, the importance of a radiation safety management field is being highlighted. We intend to help radiation workers with exposure management by identifying the degree of radiation exposure and contamination to determine an efficient method of radiation safety management. The personal exposure doses of the radiation workers at the Korea Institute of Radiological & Medical Sciences measured every quarter during a five-year period from Jan. 1, 2011 till Dec. 31, 2015 were analyzed using a TLD (thermoluminescence dosimeter). The spatial dose rates of radiation-controlled areas were measured using a portable radioscope, and the level of surface contamination was measured at weekly intervals using a piece of smear paper and a low background alpha/beta counter. Though the averages of the depth doses and the surface doses in 2012 increased from those in 2011 by about 14%, the averages were shown to have decreased every year after that. The exposure dose of 27 mSv in 2012 increased from that in 2011 in radiopharmaceutical laboratories and, in the case of the spatial dose rate, the rate of decrease in 2012 was shown to be similar to the annual trend of the whole institute. In the case of the surface contamination level, as the remaining radiation-controlled area with the exception of the I-131 treatment ward showed a low value less than $1.0kBq/m^2$, the annual trend of the I-131 treatment ward was shown to be similar to that of the entire institute. In conclusion, continuous attention should be paid to dose monitoring of the radiation-controlled areas where unsealed sources are handled and the workers therein.

• 대한방사선기술학회지:방사선기술과학
• /
• 제22권2호
• /
• pp.47-51
• /
• 1999

We calculated the energy distribution and the percentage depth-dose at 10 cm in a $10{\times}10\;cm^2$ with a photon beam at SSD of 100 cm by using a Monte Carlo Simulation. PDD is used as a beam-quality specifier for radiotherapy beams. It is better than the commonly used values of TPR or nominal accelerating potential. The presence of electron contamination affects the measurement of PDD, but can be removed by the use of a 0.1 cm lead filter. It reduces surface dose from contaminant electrons from the accelerator by more than 90% for radiotherapy beams. The filter performs best when it is placed immediately below the head. An electron-contamination correction factor is introduced to correct for electron contamination from the filter and air. It converts PDD which includes the electron contamination with the filter in place into PDD for the photons in the filtered beam. The correction factor can be used to determine stopping-power ratio. Calculations show that the values of water-to-air slopping power ratio in the unfiltered beam are related to PDD.

• 대한방사선기술학회지:방사선기술과학
• /
• 제31권4호
• /
• pp.329-335
• /
• 2008

대구시내 중 소형병원의 영상의학과 촬영실의 촬영테이블, 에어프론, 각종 손잡이, 이동형 촬영장치의 손잡이 및 방사선사의 손 등에서의 미생물의 분포를 조사하였다. 그 결과 이동형 촬영장치의 손잡이와 에어프론에서 비교적 많은 세균이 검출되었으며, 분리된 세균 중 Acinetobacter baumanni (7.3%), Klebsiella pneumoniae (6.7%), Staphylococcus aureus (3.9%), Serratia liquefaciens (1.7%), Enterobacter cloaceae (0.6%), Providenica rettgeri (0.6%)는 원내감염의 원인균으로 알려져 있다. 그리고 방사선사 손에서도 위와 유사한 집락들이 나타났는데, Klebsiella pneumoniae (8.4%), Staphylococcus aureus (6.6%), Yersinia enterocolotica (5.4%), Acinetobacter baumanni (4.2%), Enterobacter cloaceae (2.4%), Serratia liquefaciens (1.8%), Yersinia pseuotuberculosis (1.8%), Enterobacter sakazakii (1.2%), Escherichia coli (0.6%) 등의 세균이 분리되었으며, 특히 Staphylococcus aureus 와 Escherichia coli 는 강력한 병원성을 나타내기에 임상적 의의가 크다고 할 수 있다. 따라서 방사선사에게 구체적인 원내 감염에 관한 지속적인 예방교육이 필요할 것으로 사료된다.

• 한국방사선학회논문지
• /
• 제18권2호
• /
• pp.171-177
• /
• 2024

본 연구에서는 대전지역 종합병원 중 일반촬영장치, CT, MRI 검사 장치 각 2대씩 선정하여 시간대 별 검사 장치의 표면오염도를 측정하여 감염도를 예측하고 감염 예방을 위한 기초자료로 활용하고자 실험을 하였다. 그 결과 일반촬영장치와 MRI 검사장치의 시간대 별 표면 오염도는 13시>8시>16시 순이였으며, CT검사 장치는 13시>16시>8시 순이었으며 이는 검사 건수의 영향으로 나타났다. 또한 검사 장치 부위 별 표면 오염도 결과는 일반촬영장치는 Stand Bucky 손잡이, CT 검사장치는 머리받침대, MRI 검사 장치는 조작 스위치에서 ATP 오염도 수치가 가장 많이 나왔으며, 이는 접촉 건수와 밀접한 관계가 있었다. 소독 전후를 비교한 결과 소독 후 모든 장치에서 유의한 차이로 감소한 결과를 보였다. 실험 결과를 바탕으로 영상의학과 검사실의 오염도를 파악하고 감염질환을 예방할 수 있는 기초자료가 될 수 있을 것이라고 사료된다.

• Nuclear Engineering and Technology
• /
• 제55권1호
• /
• pp.295-303
• /
• 2023

Whole-body counters are widely used to assess internal contamination after a nuclear accident. However, it is difficult to determine radioiodine activity due to limitations in conventional calibration phantoms. Inhaled or ingested radioiodine is heterogeneously distributed in the human body, necessitating time-dependent biodistribution for the assessment of the internal contamination caused by the radioiodine intake. This study aims at calculating counting efficiencies considering the biodistribution of ¹³¹I in whole-body counting measurement. Monte Carlo simulations with computational human phantoms were performed to calculate the whole-body counting efficiency for a realistic radioiodine distribution after its intake. The biodistributions of ¹³¹I for different age groups were computed based on biokinetic models and applied to age- and gender-specific computational phantoms to estimate counting efficiency. After calculating the whole-body counting efficiencies, the efficiency correction factors were derived as the ratio of the counting efficiencies obtained by considering a heterogeneous biodistribution of ¹³¹I over time to those obtained using the BOMAB phantom assuming a homogeneous distribution. Based on the correction factors, the internal contamination caused by ¹³¹I can be assessed using whole-body counters. These correction factors can minimize the influence of the biodistribution of ¹³¹I in whole-body counting measurement and improve the accuracy of internal dose assessment.

• 대한방사선방어학회:학술대회논문집
• /
• 대한방사선방어학회 2010년도 춘계 학술발표회 및 심포지엄
• /
• pp.100-101
• /
• 2010