• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.05a
• /
• pp.359-360
• /
• 2018

• Journal of Sensor Science and Technology
• /
• v.27 no.4
• /
• pp.232-236
• /
• 2018

A radiation detection sensor was developed and characterized by combining three types of CsI(Tl) scintillators and an array-type SiPM to detect the radioactive contamination of discharged water in real time. The characterization results showed that type 3 exhibited the most desirable characteristics in response linearity (R-square: 0.97889) according to detection sensitivity and incident radiation dose. Furthermore, in terms of spectral characteristics, type 3 exhibited 16.54% at 0.356 MeV (the emission gamma ray energy of $^{133}Ba$), 10.28% at 0.511 MeV (the emission gamma ray energy of $^{22}Na$), 9.68% at 0.356 MeV (the emission gamma ray energy of $^{137}Cs$), and 2.55% and 4.80% at 1.173 MeV and 1.332 MeV (the emission gamma ray energies of $^{60}Co$), respectively. These measurements confirmed the good energy characteristics. The results were used to evaluate the spectral characteristics and energy linearity in a mixed source using type 3 with the best detection characteristics. It was confirmed that the gamma ray peaks of $^{133}Ba$, $^{22}Na$, $^{137}Cs$, and $^{60}Co$ were well resolved. Moreover, it was confirmed that R-square, which is an indicator of energy linearity, was 0.99986. This indicates a good linearity characteristic. Based on this study, further commercialization studies will contribute to measurements in real time and to the management of the contamination caused by radioactive wastewater or radioactive material leakage, which originate from facilities that use radioactive isotopes or care facilities.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.128-132
• /
• 2010

Purpose: Nuclear medicine general operation room is radioactive control room which is used for the handling of radioisotope(R.I). Radioactive contamination materials must be under control and separated from general trash. With this experiments, we want to actively suggest the guideline of controling and operating radioactive contamination materials by measuring contamination degree and analyzing the causes which is not realized so far. Materials and Methods: Materials are selected from Oct. 2009 to March. 2010. salines which are used for labelling radiophamaceuticals and generator cap, saline needle cap, $^{99m}Tc$-needle cap saline vial which is generated from $^{99}Mo$/$^{99m}Tc$ generator. After measuring each surface contamination degree by survey meter, mean value and standard deviation one were solved out. Results: In result, After measuring surface contamination degree, radioactivity of saline for labelling radiophamaceuticals showed $14429{\pm}26378$ cpm (p<0.05) and in measured generators, foreign imported things showed that generator cap : $9{\pm}21$ cpm, saline vial : $17{\pm}28$ cpm. saline needle cap : $35{\pm}66$ cpm, $^{99m}Tc$-needle cap : $9{\pm}21$ cpm, saline vial $13{\pm}28$ cpm. domestic things showed that generator cap : $22852{\pm}52545$ cpm, saline needle cap : $87367{\pm}109711$ cpm, $^{99m}Tc$-needle cap : $9008{\pm}10459$ cpm, saline vial : $186416{\pm}158196$ cpm (p<0.05). Conclusion: The saline which is used for labelling, exceeded 1/10 of maximum permissible range. this is generated from radiophamaceuticals dilution procedure. and In generators, radioactive value of foreign import things showed closely background value. but which of domestic thing showed that exceeded more than 1000 values 1/10 of maximum permissible range. the causes of that is domestic generator is contaminated in manufacturing procedure. So, to dispose radioactive contamination materials which is could betaken out of, the control and operation must be radical under controlled by radioactive measuring, recording and equipping of its own. if this is kept well, we can prevent surely that radioactive waste could be disposed like as general trash.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2004.02a
• /
• pp.42-50
• /
• 2004

The pool $(3m{\times}6m{\times}10m{\times}$ in Irradiated Materials Examination Facility is generally used to transport irradiated materials between a moving cask and hot-cell. During the operation in the pool such as loading/unloading the cask, holding specimen and bucket elevation, water maybe contaminated by radioactive or contaminated impurities from irradiated materials. Then, it must be purified and filtered continuously to keep lower radioactivity than that of regulation prescribed by RCA Korea Activity in a part of radioactive contamination control. This paper described radioactive contamination distribution of water as transported materials, which is related to effective operation of purification and filtration system.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2009.06a
• /
• pp.84-85
• /
• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.

• Journal of Radiation Protection and Research
• /
• v.27 no.3
• /
• pp.165-170
• /
• 2002

Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than thy deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.05a
• /
• pp.227-228
• /
• 2018

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.05a
• /
• pp.371-372
• /
• 2018

• Journal of Radiation Industry
• /
• v.11 no.3
• /
• pp.123-130
• /
• 2017

Concerns about high radiation exposure to the hands of radiation workers who may contact with radioactive contamination on surfaces in a nuclear power plant (NPP) had been raised, and the Korean regulatory body required the extremity dose estimation during contact tasks with radioactive materials. Korean NPPs conducted field tests to identify the incident radiation to the hands of radiation workers who may contact with radioactive contamination during maintenance periods. The results showed that the radiation fields for contact tasks are dominated by high energy photons. It was also found that the radiation doses to the hands of radiation workers in Korean NPPs were much less than the annual dose limits for extremities. This approach can be applicable to measure and estimate the extremity dose to the hands of medical workers who handle the radioactive materials in a hospital.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2005.11b
• /
• pp.269-279
• /
• 2005

In this study, detectors characteristics for simultaneous counting of alpha and beta ray in a pipe were estimated. The detector were composed of thin ZnS(Ag) scintillator and plastic detector. The scintillator for counting alpha particles has been applied a polymer composite sheet, having a double layer structure of an inorganic scintillator ZnS(Ag) layer adhered onto a polymer sub-layer. The other for counting beta particles used a commercially available plastic scintillator. It was confirmed that the detectors were suitable for counting the in-pipe contamination.