• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2004.11a
• /
• pp.252.1-252.1
• /
• 2004

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.11
• /
• pp.99-106
• /
• 2016

When radon is staying at alveoli and bronchial tubes, the collapse of radon creates progeny nuclides (alpha ray, beta ray, gamma ray, etc.). They emit radiation causing a mutation in the chromosome of the cell, resulting in lung cancer. In other words, the main cause of lung cancer is radiation emitting as the result of radon collapse rather than radon gas. The 82% of radiation exposed to people is the natural radiation. Most of the natural radiation is radon. If we properly control the concentration of radon indoors, the probability of occurrence of lung cancer could be decreases to be 70%. Until now, to measure the indoor radon concentration, imported radon sensors are needed. So, DB construction of indoor radon emission and popular radon measuring apparatus should be developed. In this paper, we propose the radon detecting method using PIN photodiode. Also, we confirmed the PIN photodiode could be used as radon sensor module through some experimental studies.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.1
• /
• pp.15-21
• /
• 2017

WHO reported that millions of people die every year because of diseases induced from environmental pollution. In 2012, approximately 7 million people were killed due to air pollution. Major cause of such pollution includes toxin, chemical waste, radiation and air pollution. Therefore, the significance and interest to indoor air quality has been continuously increased. Especially, the interest in radon, the ARC group 1 carcinogen, is rapidly increasing, and banning the use of construction materials that release radon, repairing aged buildings, and developing ventilators. To reduce the level of radon gas was inflowed to indoors and outdoors, this study is to research and develop a radon gas absorption board using absorbents. The absorbents utilized to absorb the radon gas were porous diatomite, natural zeolite, 4A zeolite and 13X zeolite and employed bentonite and illite, montmorillonites with the property of exchanging anions. As the main binder, magnesium oxide was used, with a content of 25% magnesium chloride.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.3 no.4
• /
• pp.23-36
• /
• 2000

Bottom sea waters in eight stations including from inner bay to outer bay to understand the importance of the submarine groundwater discharge for the environmental assessment of Chinhae Bay was collected in August 1999 and January 2000. Generally, /sup 222/Rn is very useful tracer to assess the submarine groundwater discharge because it is 2-4 orders of magnitude more concentrated in groundwater compared to surface water. The /sup 222/Rn activities ranged between about 33 to 182 dpm/100kg within the bay. Higher activities more than 100 dpm/100kg were found at the inner bay. The /sup 226/Ra activities, its parent, however, were little different between stations. /sup 222/Rn activities at the same station varied with season. It suggests that the major source of /sup 222/Rn is not from the bottom sediment, but from the change of submarine groundwater discharge by precipitation. The contents of Cl/sup -/ and SO/sub 4//sup 2-/ in the groundwater of Wonjeon-ri were very high as 1,312 and 369 ppm, respectively, indicating that this groundwater along the Chinhae coast was affected by seawater. Therefore, the submarine groundwater in the inner Bay may discharge to the overlying water. It indicates that these submarine groundwater discharges may play an important role as another important source of nutrients in the Chinhae Bay, because groundwater around the Chinhae Bay showed high concentration of dissolved inorganic nutrients (average , nitrate>174 μM, silicate>262 μM). Therefore, further studies are required to assess the contribution by the submarine groundwater discharge in the biogeochemical processes of the Chinhae Bay.

• Journal of Radiation Protection and Research
• /
• v.11 no.2
• /
• pp.130-138
• /
• 1986

A study on the measurement of alpha activity in ground air has been carried out using CA 80-15 and LR 115-1 cellulose nitrate nuclear track detectors. The detection efficiency of the detectors were determined by making use of an $^{241}Am$ alpha source of $0.1{\mu}Ci$ in activity under a known geometrical arrangement. For the field measurement of alpha activity of emanated radon and its progeny in ground air two different radon cups were installed for a certain period of time in two neighbouring ground holes of about 15 cm in diameter and 45 cm in depth. Of the two radon cups one kept closed space during the detecting period, while the other kept open space with a hole enabling the air to ventilate. The etched tracks were read out by a microscope and the results obtained through statistical analysis were evaluated in terms of alpha activity per unit volume of air.

• Analytical Science and Technology
• /
• v.18 no.1
• /
• pp.5-12
• /
• 2005

It has been established that soft error of high precision electronic circuits can be induced by alpha particles emitted from the naturally occurring radioactive impurities such as U, and Th. As the electronic circuits have recently become lower dimension and higher density, these alpha-particle emitting radioactive impurities have to be strictly controlled. The aim of this study is to develop of NAA (Neutron Activation Analysis) and gamma-spectrometry to improve the analytical sensitivity and precision of U and Th. A new NAA method has been established using the HTS (Hydrulic transfer system) irradiation facility which has been used to produce radioisotopes for industries and medicines instead of the PTS (pneumatic transfer system) irradiation facility which has been used in general NAA. When the ultratrace impurities have to be analyzed by NAA, background gamma-ray spectra induced from $^{222}Rn$ and its progenies in air is serious problem. This unstable background has been eliminated or stabilized by the use of a nitrogen purging system. Ultra trace amounts of U (0.1 ng/g) and Th (0.01 ng/g) in high purity silica used for EMC could be analyzed by the use of HTS-NAA and low background gamma-spectrometry.