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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Radiation Protection and Research
Journal Basic Information
Journal DOI :
Korean Association for Radiation Protection
Editor in Chief :
Volume & Issues
Volume 34, Issue 4 - Dec 2009
Volume 34, Issue 3 - Sep 2009
Volume 34, Issue 2 - Jun 2009
Volume 34, Issue 1 - Mar 2009
Selecting the target year
POLARITY AND ION RECOMBINATION CORRECTION FACTORS OF A THIMBLE TYPE IONIZATION CHAMBER WITH DEPTH IN WATER IN THE MEGAVOLTAGE BEAMS
Kim, Seong-Hoon ; Huh, Hyun-Do ; Choi, Sang-Hyun ; Min, Chul-Hee ; Shin, Dong-Oh ; Choi, Jin-Ho ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 43~48
When the PDD (percentage depth dose) in the megavoltage beams is measured in the water phantom, the polarity and ion recombination effects of ionization chambers with depth in water are not usually taken into consideration. We try to investigate if those variations with depth should be taken into consideration or could be ignored for the thimble type semiflex ionization chamber (PTW
, SN 1551). According to the recommendation of IAEA TRS-398, the 4 representative depths of
were used for the electron beams. For the photon beams, the 4 depths were arbitrarily chosen for the photon beams, which were
. For the high energy photon beam both polarity and ion recombination factors of the chamber with depth in water gives the good agreements within the maximum
0.2%, while the
with depth came within the maximum
0.4% and the
within the maximum
0.6% in every electron beam used. This study shows that PDI (percentage depth ionization) could be a good approximation to PDD for the chamber used.
INDUCTION OF MITOCHONDRIAL DNA DELETION BY IONIZING RADIATION IN HUMAN LUNG FIBROBLAST IMR-90 CELLS
Eom, Hyeon-Soo ; Jung, U-Hee ; Park, Hae-Ran ; Jo, Sung-Kee ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 49~54
Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging and also contributes to their unfavorable effects in cultured cells and animal tissues. This study was conducted to investigate the effect of ionizing radiation (IR) on mtDNA deletion and the involvement of reactive oxygen species (ROS) in this process in human lung fibroblast (IMR-90) cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated with
-rays and the intracellular ROS level was determined by 2',7'-dichlorofluorescein diacetate (DCFH-DA) and mtDNA common deletion (4977bp) was detected by nested PCR. Old cells at PD 55 and
-treated young cells were compared as the positive control. IR increased the intracellular ROS level and mtDNA 4977 bp deletion in IMR-90 cells dose-dependently. The increases of ROS level and mtDNA deletion were also observed in old cells and
-treated young cells. To confirm the increased ROS level is essential for mtDNA deletion in irradiated cells, the effects of N-acetylcysteine (NAC) on IRinduced ROS and mtDNA deletion were examined. 5 mM NAC significantly attenuated the IR-induced ROS increase and mtDNA deletion. These results suggest that IR induces the mtDNA deletion and this process is mediated by ROS in IMR-90 cells.
DEVELOPMENT OF THE DUAL COUNTING AND INTERNAL DOSE ASSESSMENT METHOD FOR CARBON-14 AT NUCLEAR POWER PLANTS
Kim, Hee-Geun ; Kong, Tae-Young ; Han, Sang-Jun ; Lee, Goung-Jin ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 55~64
In a pressurized heavy water reactor (PHWR), radiation workers who have access to radiation controlled areas submit their urine samples to health physicists periodically; internal radiation exposure is evaluated by the monitoring of these urine samples. Internal radiation exposure at PHWRs accounts for approximately 20
40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Carbon-14 is not a dominant nuclide in the radiation exposure of workers, but it is one potential nuclide to be necessarily monitored. Carbon-14 is a low energy beta emitter and passes relatively easily into the body of workers by inhalation because its dominant chemical form is radioactive carbon dioxide (
). Most inhaled carbon-14 is rapidly exhaled from the worker's body, but a small amount of carbon-14 remains inside the body and is excreted by urine. In this study, a method for dual analysis of tritium and carbon-14 in urine samples of workers at nuclear power plants is developed and a method for internal dose assessment using its excretion rate result is established. As a result of the developed dual analysis of tritium and carbon-14 in urine samples of radiation workers who entered the high radiation field area at a PHWR, it was found that internal exposure to carbon-14 is unlikely to occur. In addition, through the urine counting results of radiation workers who participated in the open process of steam generators, it was found that the likelihood of internal exposure to either tritium or carbon-14 is extremely low at pressurized water reactors (PWRs).
EFFECT OF METAL CONTACT ON THE CZT DETECTOR PERFORMANCE
Park, Se-Hwan ; Park, Hyung-Sik ; Lee, Jae-Hyung ; Kin, Han-Soo ; Ha, Jang-Ho ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 65~68
Metal-semiconductor contact is very important for the operating property of semiconductor detector.
Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.
A Development of GUI Full-Energy Absorption Peak Analysis Program for Educational Purpose
Sohn, Jong-Wan ; Shin, Myung-Suk ; Lee, Hye-Jung ; Jung, Kyung-Su ; Jeong, Min-Su ; Kim, Sang-Nyeon ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 69~75
To obtain precise information about characteristics of gamma ray detector system responses, we developed new GUI computer program to analize full-energy absorption peak using our developed Delphi computer code for educational purpose. By use of the well known 4 nonlinear peak shaping functions, peaks were fitted with least square fit method in this code. In this paper, we described the methods to search for 12 coefficients in above 4 nonlinear peak shaping functions by use of our developed code in details. The computer code was tested for 1
661 keV gamma ray peak spectrum detected by 25 % relative efficiency HPGe detector with 5.35 cm (D)
5.5 cm (L) size.
A LONG-TERM FIELD TEST OF A LARGE VOLUME IONIZATION CHAMBER BASED AREA RADIATION MONITORING SYSTEM DEVELOPED AT KAERI
Kim, Han-Soo ; Ha, Jang-Ho ; Park, Se-Hwan ; Kim, Jung-Bok ; Kim, Young-Kyun ; Jin, Hyung-Ho ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 77~81
An Area Radiation Monitoring System (ARMS) ionization chamber, which had an 11.8 L active volume, was fabricated and performance-tested at KAERI. Low leakage currents, linearities at low and high dose rates were achieved from performance tests. The correlation coefficients between the ionization currents and the dose rates are 1 at high dose rate and 0.99 at low dose rate. In this study, an integration-type ARMS ionization chamber was tested over a year for an evaluation of its long-term stability at a radioisotope (RI) repository of the Young-gwang nuclear power plant. The standard deviation of dose rate of 1 day data and over a 100-days mean value were 6.2
R/h and 2.9
R/h, respectively. The fabricated ARMS ionization chamber showed stable performance from the results of the long-term tests. Design and performance characteristics of the fabricated ionization chamber for the ARMS from performance-tests are also addressed.
CHARACTERISTICS EVALUATION AND GROWTH OF
SINGLE CRYSTAL BY CZOCHRALSKI METHOD
Cho, Yun-Ho ; Kim, Yong-Kyun ; Lee, Woo-Gyo ; Kang, Byoung-Hwi ; Kim, Jong-Kyung ; Lee, Dong-Hoon ; Park, Jae-Woo ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 83~86
The single crystal scintillator of bismuth germinate (
:BGO) was successfully grown by the conventional Czochraski technique. The characteristics of the grown BGO were evaluated and presented on the excitation, emission responses and energy spectra of the
radio-isotopes. The energy resolution of grown BGO,
E/E, was estimated to be 12.1% at 662 keV of
nuclide. Compared to the commercial BGO crystal, we confirmed that the grown BGO has a good performance and is comparable to reference one.
Analysis of Metabolism and Effective Half-life for Tritium Intake of Radiation Workers at Pressurized Heavy Water Reactor
Kim, Hee-Geun ; Kong, Tae-Young ;
Journal of Radiation Protection and Research, volume 34, issue 2, 2009, Pages 87~94
Tritium is the one of the dominant contributors to the internal radiation exposure of workers at pressurized heavy water reactors (PHWRs). This nuclide is likely to release to work places as tritiated water vapor (HTO) from a nuclear reactor and gets relatively easily into the body of workers by inhalation. Inhaled tritium usually reaches the equilibrium of concentration after approximately 2 hours inside the body and then is excreted from the body with a half-life of 10 days. Because tritium inside the body transports with body fluids, a whole body receives radiation exposure. Internal radiation exposure at PHWRs accounts for approximately 20-40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Thus, tritium is an important nuclide to be necessarily monitored for the radiation management safety. In this paper, metabolism for tritium is established using its excretion rate results in urine samples of workers at PHWRs and an effective half-life, a key parameter to estimate the radiation exposure, was derived from these results. As a result, it was found that the effective half-life for workers at Korean nuclear power plants is shorter than that of International Commission on Radiological Protection guides, a half-life of 10 days.