Despite its advantages such as safety, unnecessary pretreatment, and decontamination of waste with complex geometry, conventional ultrasonic decontamination technology has been only used to remove loose contaminants, oil and grease, not fixed contaminants due to the limitations in increasing the intensity in the high frequency range. Thus, ultrasound has been used as an auxiliary method to accelerate chemical decontamination of radioactive wastes or chemicals were added to the solution to increase the decontamination efficiency. The recently developed high-intensity focused ultrasound (HIFU) decontamination technology overcomes these limitations by combining multiple frequencies of ultrasonic waves in a specific arrangement, making it possible to remove most fixed contaminants, including radioactive micro particles less than 1 micrometer within half an hour. KEPCO NF and EnesG developed mobile HIFU decontamination equipment and successfully demonstrated the decontamination effect on various radionuclides found in nuclear power plants by treating radioactive metal waste to the level below free release criteria. The mobile HIFU decontamination equipment used in the demonstration can be operated anywhere where water is supplied, including controlled area in nuclear power plants, and is expected to be used widely for decontamination and free release of metal radioactive wastes.

As contemporary building construction type is getting higher and deeper, construction equipment usage is getting more, and related fatal accidents are on an increasing trend. Because of this, a method was drawn which could grasp the present state of construction equipment management and manage safety of the equipment more easily for accident prevention by choosing 2 kinds of Construction equipment which cause safety accident frequently among the equipment mainly used in construction site. This study suggested a method about construction equipment safety management using "smart phone" base which could be used in safety management for construction equipment by whomever in construction site. After attachment of QR code included safety checklist, It became possible that site managers could check more efficiently by scanning with their smart phone when they inspect equipment. Moreover, by the construction interested who didn't know what and how they have to inspect could point out unsafe condition in the early stage of equipment entering or take unsafe one out of the site by using new smart phone safety checking system is installed, it became possible that critical accident caused by construction equipment was prevented in advance.

As contemporary building construction type is getting higher and deeper,construction equipment usage is getting more, and related fatal accidents are on an increasing trend. In these days, due to the deteriorating construction business circumstance, job finding problem of equipment operator, and dumping contract, equipment lease suppliers are putin jeopardy. In high-rise building construction, especially tower crane, mobile elevated work platform and other High place operation cars among construction equipment cause many critical accidents because of drop supply of construction biding bringing out dumping contract could cause unsafe and poor construction management. Because of this, a method was drawn which could grasp the present state of construction equipment management and manage safety of the equipment more easily for accident prevention by choosing 2 kinds of Construction equipment which cause safety accident frequently among the equipment mainly used in construction site. This study suggested a method about construction equipment safety management using ‘‘smart phone’ base which could be used in safety management for construction equipment by whomever in construction site. After attachment of QR code included safety checklist, It became possible that site managers could check more efficiently by scanning with their smart phone when they inspect equipment. Moreover, by the construction interested who didn’t know what and how they have to inspect could point out unsafe condition in the early stage of equipment entering or take unsafe one out of the site by using new smart phone safety checking system is installed, it became possible that critical accident caused by construction equipment was prevented in advance.

This research has so far found out problems including the second damage of extinguishant and the short time of emission when using the existing dry chemical extinguisher and gas type extinguisher, and impossibility of constant extinguishing due to the inability of recharge at the field. To solve such problems, a mobile water mist system was developed and used. However, it is judged that more improved mobile water mist system is necessary because the force of the fire changed diversely and remote villages in mountains or islands where the force of fire extinguishing is short or delayed, require high capacity of fire extinguishing. Therefore a new equipment was developed and tested focusing on the improvement of extinguishing capacity and the performance of extinguishing was found out to be improved, compared to the existing mobile water mist system. It also showed a superior extinguishing capacity to dry chemical extinguisher or gas type extinguisher. Afterward an additional research is required of simplification of equipment, price cutting and the development of additive to enable high performance even with just small extinguishant.