• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.37-44
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• 1995

Since provisions on the technical criteria for personnel dosimetry was amended three years ago, several improvements in the technique of monitoring personnel doses by TLD have taken place, but for the photograpfic film as a personnel monitor, additional investigations should be carried out for its accuracy of dose estimates because of its wide use in the radiation involved industries. So, this paper describes the methods to develope dose evaluation algorithm for photographic film using ISO reference radiations by i) empirical formula, ii) degree-of-fit method, and iii) matrix approximation. These methods show a good agreement between irradiated and calculated dose within tolerance level represented in ANSI N13. 11, and can be used for the dose evaluation of X, ${\gamma}$ and/or radiation fields.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.409-415
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• 2014

In this study, radiation doses of major organs in various postures in lower extremity teleography were measured and compared to investigate the utility of the test methods. Ten adult males who underwent lower extremity teleography at a tube voltage of 73 kVp, tube current of 32 mAs, and SID of 180 cm. Using rando phantom, glass dosimeter was attached to the eye lens, thyroid gland, and genital gland to measure the radiation dose in each area 5 times in each anteroposterior posture and posteroanterior posture. The results were compared and analyzed through Paired T-test. The images from the anteroposterior posture and posteroanterior posture were evaluated through the blind test on a scale of 5. As a result, the posteroanterior method could reduce the dose than the anteroposterior posture method: less dose for the eye lens by 6%, thyroid gland by 6%, and genital gland by 26%. Since there was no significant difference in image evaluation, the posteroanterior posture is considered better than the anteroposterior posture in lower extremity teleography.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.49-55
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• 2017

In the case of nuclear medicine practitioners in medical institutions, a wide range of exposure dose to individual workers can be found, depending on the type of source, the amount of radioactivity, and the use of shielding devices in handling radioactive isotopes. In this regard, this study evaluated the organ dose on practitioners as well as the dose reduction effect of the L-block shielding device in handling the diagnostic radiation source through the simulation based on the Monte Carlo method. As a result, the distribution of organ dose was found to be higher as the position of the radiation source was closer to the handling position of a practitioner, and the effective dose distribution was different according to the ICRP tissue weight. Furthermore, the dose reduction effect according to the L-block thickness tended to decrease, which showed the exponential distribution, as the shielding thickness increased. The dose reduction effect according to each radiation source showed a low shielding effect in proportion to the emitted gamma ray energy level.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.290-299
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• 2003

고준위 방사성 폐기물 처분장으로부터 유출된 핵종이 인간 생태계에 도달하여 어느 정도의 선량률로서 피폭을 일으키는가를 보이기 위한 생태계 피폭 모델링 및 평가 연구는 처분안전성 평가의 최종 단계로서 핵종 유출의 결과가 인간에게 어느 정도의 방사선 피폭을 주는가를 보이는 것이 그 주요한 내용이 된다. 이 연구를 통하여 도출된 시나리오 중에서 가장 기본이 될 수 있는 생태계에 대하여 AMBER를 사용하여 피폭 계산을 수행하여 선량 환산 인자 평가를 계산해 보았다. AMBER 코드는 핵종 이동 계산을 위해 여러 개의 구획을 설정하고 구획간의 핵종 이동은 핵종 전이 계수(mass transfer coefficient)를 이용하여 계산한다.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.42-43
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• 2011

• Analytical Science and Technology
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• v.20 no.6
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• pp.460-467
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• 2007

Dose rate conversion factor was calculated to estimate the absorbed effective annual doses for soils for the beta-rays and gamma-rays, which were emitted from $^{238,235}U$, $^{232}Th$, and $^{40}K$ isotopes. The most recent data of the emitted energies per decay, half-lifes, and branching ratios, which were obtained from National Nuclear Data Center, were used. When this factor and the effective annual doses for the beta-rays and the gamma-rays of natural radioisotopes were compared with those of Aitken, these of $^{238}U$, $^{232}Th$ and $^{40}K$ are estimated to have good agreements but a large difference is shown in this for $^{235}U$. Through the calculations of effective annual doses by using these factor and the measurements of gamma-ray spectra for soils, which were extracted from prehistoric remains (Mansuri) on Osong, Chungchengbuk-do, The annual effective doses were obtained to be 3.8~5.9 mGy/yr. Also, when these doses including decay elements upper Rn were compared with those on all isotopes, the differences within 9~30 % were obtained. The analysis method of the annual effective doses for the beta-rays and the gamma-rays of the natural isotopes of soils was established by this dose rate conversion factor.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.571-576
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• 1998

방사성물질의 수송용기 등에 사용되는 에폭시수지계 중성자 차폐재를 제조하였다 기본물질은 재질(KNS-102) 및 수소 첨가된 비스페놀 A힘(KNS-106) 그리고 패놀-노블락형 에폭시수지 (KNS-611)이며, 첨가제로는 수산화알루미늄 및 탄화붕소이다. 이들 중성자 차폐재들은 유동성이 좋아 수송용기와 같은 복잡한 구조에 사용할 수 있다. 제조된 중성자 차폐재들을 방사선 조사선 량에 대한 영향과 가압경수로 사용후핵연료_ 28다발을 수송할 수 있는 수송용기에 적용하여 차폐능 평가를 수행하였다 0.7 MGy 까지 중성자 차폐재들은 방사선 조사선량의 증가에 따라 중성자 차폐재의 거시적 제거 단면적($\Sigma$$_{R}$)은 약간 증가하는 경향을 나타내었으며, 수송용기에 적용하여 ANISN 전산코드로 차폐능 평가를 수행한 결과 정상수송시 중성자 차폐재의 두께가 12 cm 이상일 때 수송용기 반경방향표면에서 최대 방사선량율은 168 ~ 214 $\mu$Sv/h로 나타났으며, 수송용기 표면에서 100 cm 지점에서의 최대 방사선량율은 74 ~ 93 $\mu$Sv/h로 나타났다. 이들은 모두 관련된 법규들에서 규정된 최대 허용방사선량율을 만족하는 것으로 나타났다.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.181-190
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• 2012

Naturally occurring radioactive materials (NORM) in building materials are main sources of external radiation exposure to the general public. The objective of this study was to assess external radiation dose in Korean dwellings due to NORM in concrete walls. Reference room model for dose assessment was made by analyzing room structure and housing scale of Korean dwellings. In addition, dose assessments were made for varying room sizes. Absorbed doses to air and effective dose rates were calculated using radiation transport code MCNPX. Assuming a reference room of $3{\times}4{\times}2.8m^3$, absorbed dose rates in air were 0.80, 0.97, 0.08 nGy $h^{-1}$ per Bq $kg^{-1}$ for uranium series, thorium series, and $^{40}K$, respectively. Effective dose rates were 0.57, 0.69, 0.058 nSv $h^{-1}$ per Bq $kg^{-1}$, respectively. Radiation dose resulting from concrete of ceiling and floor increased with room area while radiation dose from concrete of walls decreased with room area. Therefore, total radiation doses were almost the same for the varying room area from 5 to $30m^2$. Effective dose in Korean dwellings was calculated based on measurement data of NORM concentration in concrete and occupancy fraction of Korean population by location. Annual effective dose was 0.59 mSv assuming that indoor occupancy fraction was 0.89 and concentrations of uranium series, thorium series and $^{40}K$ were 26, 39, 596 Bq $kg^{-1}$, respectively. Finally, annual effective dose in Korean dwellings can be calculated by the following equation: Effective dose=indoor occupancy fraction${\times}8760\;h\;y^{-1}{\times}(0.57C_U+0.69C_{Th}+0.058C_K)$.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.76-77
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• 2011

• Nuclear industry
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• v.7 no.9 s.55
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• pp.66-70
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• 1987

방사선량이 선량한도 이내인가를 확인하는 모니터링을 위한 앞으로의 과제는 임의의 데이터 처리기능 등 데이터관리의 고도화에 있다. 일본 동경사업소의 연구는 현행모니터링의 보충조사와 고도화, 대형재처리시설의 안전평가 방법 확립에 노력하고 있다.