• Title/Summary/Keyword: 유효선량평가

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A Study on the Effect of Containment Filtered Venting System to Off-site under Severe Accident (중대사고시 격납건물여과배기계통(CFVS)적용으로 인한 사고영향과 결과 고찰)

  • Jeon, Ju Young;Kwon, Tae-Eun;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.40 no.4
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    • pp.244-251
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    • 2015

  • The containment filtered venting system reduces the range of the contamination area around the nuclear power plant by strengthening the integrity of the containment building. In this study, the probabilistic assessment code MACCS2 was used to assess the effect of the CFVS to off-site. The accident source term was selected from a Probabilistic Safety Analysis report of SHINKORI 1&2 Nuclear Power Plant. The three source term categories from 19 STC were chosen to evaluate the effective dose and thyroid dose of residents around the power plant and the dose with CFVS and without CFVS were compared. The dose was calculated according to the distance from the nuclear power plant, so the damage scale based on the distance that exceeds the IAEA criteria for effective dose (100 mSv per 7 days) and thyroid dose (50 mSv per 7 days) were compared. The effective dose reduction rates of the STC-3, STC-4, STC-6 were about 95-99% in the whole range (0~35 km), 96-98% for the thyroid dose. There are similar results between effective dose and thyroid dose. After applying the CFVS, the damage scale that exceeds the effective dose criteria was about 1 km (mean). Especially, the STC-4 damage scale was decreased from 26 km (mean) to 1.2 km (mean) significantly. The damage scale that exceed the thyroid dose criteria was decreased to 2~3 km (mean). The STC-4 damage scale was also decreased significantly as compared to STC-3, STC-6 in terms of effective dose.

  • https://doi.org/10.14407/jrp.2015.40.4.244 인용 PDF KSCI

Characterization of Radiation Field in the Steam Generator Water Chambers and Effective Doses to the Workers (증기발생기 수실의 방사선장 특성 및 작업자 유효선량의 평가)

  • Lee, Choon-Sik;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.24 no.4
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    • pp.215-223
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    • 1999

  • Characteristics of radiation field in the steam generator(S/G) water chamber of a PWR were investigated and the anticipated effective dose rates to the worker in the S/G chamber were evaluated by Monte Carlo simulation. The results of crud analysis in the S/G of the Kori nuclear power plant unit 1 were adopted for the source term. The MCNP4A code was used with the MIRD type anthropomorphic sex-specific mathematical phantoms for the calculation of effective doses. The radiation field intensity is dominated by downward rays, from the U-tube region, having approximate cosine distribution with respect to the polar angle. The effective dose rates to adults of nominal body size and of small body size(The phantom for a 15 year-old person was applied for this purpose) appeared to be 36.22 and 37.06 $mSvh^{-1}$) respectively, which implies that the body size effect is negligible. Meanwhile, the equivalent dose rates at three representative positions corresponding to head, chest and lower abdomen of the phantom, calculated using the estimated exposure rates, the energy spectrum and the conversion coefficients given in ICRU47, were 118, 71 and 57 $mSvh^{-1}$, respectively. This implies that the deep dose equivalent or the effective dose obtained from the personal dosimeter reading would be the over-estimate the effective dose by about two times. This justifies, with possible under- or over- response of the dosimeters to radiation of slant incidence, necessity of very careful planning and interpretation for the dosimetry of workers exposed to a non-regular radiation field of high intensity.

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Assessment of the Effective Dose to the Human Body and Estimation of Lifetime Attributable Risk by CT Examination (CT 검사별 노출되는 유효선량과 생애 암 귀속 위험도 평가)

  • Cho, Yong In;Kim, Jung Hoon
    • Journal of the Korean Society of Radiology
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    • v.14 no.2
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    • pp.169-178
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    • 2020

  • The number of CT scans is increasing every year due to the improvement of the medical standards of the public, and thus the annual dose of medical radiation is also increasing. In this study, we evaluated the effective dose of the human body exposed to CT scans and estimated LAR. First, five region were selected from the CT diagnostic reference level guideline, and the effective dose of human body exposed to each examination was evaluated by clinical CT device. Second, the human organs and effective dose were calculated using the ALARA-CT program under the same conditions. Third, lifetime attributable risk (LAR) estimated by the effective dose exposed through the previous CT scan was estimated. As a result, the most effective dose was 21.18 mSv during the abdomen 4 phase scan, and the dose level was below DRL for all other tests except for the abdominal examination. As a result of evaluating effective dose using a dose calculation program under the same conditions, the results showed about 1.1 to 1.9 times higher results for each examination. In the case of organ dose, the closer the organ to the scan site, the higher the scattering ray. The lifetime attributable risk to CT radiation dose in adults was gradually decreased with age, and the results were somewhat different according to gender.

  • https://doi.org/10.7742/jksr.2020.14.2.169 인용 PDF KSCI HTML

Assessment of Effective Dose from Diagnostic X-ray Examinations of Adult (진단X선에 의한 성인의 진단행위별 유효선량평가)

  • Kim, Woo-Ran;Lee, Choon-Sik;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.27 no.3
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    • pp.155-164
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    • 2002

  • Methodology to evaluate the effective doses to adults undergoing various diagnostic x-ray examinations were established by Monte Carlo simulation of the x-ray examinations. Anthropomorphic mathematical phantoms, the MIRD5 male phantom and the ORNL female phantom, were used as the target body and x-ray spectra were produced by the x-ray spectrum generation code SPEC78. The computational procedure was validated by comparing the resulting doses to the results of NRPB studies for the same diagnostic procedures. The effective doses as well as the organ doses due to chest, abdomen, head and spine examinations were calculated for x-rays incident from AP, PA, LLAT and RLAT directions. For instance, the effective doses from the most common procedures, chest PA and abdomen AP, were 0.029 mSv and 0.44 mSv, respectively. The fact that the effective dose from PA chest x-ray is far lower than the traditional value of 0.3 mSv(or 30 mrem), which results partly from the advances of technology in diagnostic radiology and partly from the differences in the dose concept employed, emphasizes necessities of intensive assessment of the patient doses in wide ranges of medical exposures. The methodology and tools established in this study can easily be applied to dose assessments for other radiology procedures; dose from CT examinations, dose to the fetus due to examinations of pregnant women, dose from pediatric radiology.

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