The use of nuclear materials for nuclear power generation is increasing worldwide, and the International Atomic Energy Agency (IAEA) has signed an agreement with countries using nuclear materials to prevent using military purpose through the Non-Proliferation Treaty (NPT) for the management of nuclear materials. Accordingly, all member countries manage nuclear material and equipment facilities under the treaty and are obligated to conduct safety measures such as inspection, containment, and surveillance in accordance with safety standards. The equipment used in the inspection basically consists of a Scintillator type and a semiconductor detector type, and is mainly used for portable equipment to ensure the integrity of the equipment. In general, the operating environment of the detector guaranteed by the manufacturer is -10 degrees to 40 degrees due to poor resolution and electrical problems. However, in the case of an outdoor environment other than a laboratory environment, it is difficult to maintain the above temperature conditions. In particular, the internal temperature of the vehicle used for transport rises to more than 50 degrees in Korea, making the detector stored therein vulnerable. In this study, a storage chamber for extreme environments was developed. The developed chamber compared the internal temperature by heating the external temperature. In addition, the performance before and after heating was compared by heating the radiation detectors HPGe, CZT, and NaI from -20 to 70 degrees Celsius while using the storage chamber. Our proposed chamber can play a key role in applications with good performance in complex environmental adaptability in their design.
Recently, measuring instruments for SHM of structures has been developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to the absence of triboelectric noise and elimination of the requirement of a cumbersome cable. However, in extreme environments, the sensor may be less sensitive to temperature changes and to the distance between the sensor and data logger. This may compromise on the performance of the sensor and instrumentation. Therefore, in this paper, free vibration experiments were conducted using wireless MEMS sensors at an actual site. Measurement was assessed in time and frequency domain by changing the temperature variation at(- 8℃, - 12℃ and - 16℃) and the communication distance (20m, 40m, 60m, 80m).
To properly maintain steel structures, it is important to investigate the corrosivity of structural member. In this study, atmospheric exposure tests were carried out for 1 year using monitoring steel plates (MSP). In addition, atmospheric corrosion environment were also monitored by temperature and humidity sensor, corrosion monitoring (ACM) sensors, etc.
Recently efficient maintenance technology has been rising because of the structural deterioration. Specific technology development and research related to the real-time monitoring has been conducted in various ways. All-in-one enclosure including GPS was fabricated to measure the displacement of the retaining wall structure exposed the extreme environment such as very high and low temperature. Also it measured the displacement of the structure under the phased construction.