Laser scabbling has the potential to be a valuable technique capable of effectively decontaminating highly radioactive concrete surface at nuclear decommissioning sites. Laser scabbling tool using an optical fiber has a merits of remote operation at a long range, which provides further safety for workers at nuclear decommissioning sites. Furthermore, there is no reaction force and low secondary waste generation, which reduces waste disposal costs. In this study, an integrated decontamination system with laser scabbling tool was employed to test the removal performance of the concrete surface. The integrated decontamination system consisted of a fiber laser, remote controllable mobile cart, and a debris collector device. The mobile cart controlled the translation speed and position of the optical head coupled with 20 m long process fiber. A 5 kW high-powered laser beam emitted from the optical head impacted the concrete block with dimensions of 300 mm × 300 mm × 80 mm to induce explosive spalling on its surface. The concrete debris generated from the spalling process were collected along the flexible tube connected with collector device. We used a three-dimensional scanner device to measure the removed volume and depth profile.

Laser scabbling experiments were conducted with the aim of developing concrete decontamination technology. Laser scabbling system contains a 6 kW fiber laser (IPG YLS-6000, λ=1,070 nm) and optical head, which are connected with process fiber (core dia.: 600 μm, length: 20 m). Optical head consists of two lenses (f = 160 mm and 100 mm) to collimate and focus laser beam. The focused laser beam is passed through the small diameter of nozzle (throat dia.: 3 mm) to prevent the laser-produced debris into head. And then, the focused beam is directed toward concrete block as continuously diverging. The diverged laser beam was incident on the high-strength concrete with 300 mm (length) × 300 mm (height) × 80 mm (width) to induce explosive spalling on the concrete surface. The optical head was moved by X-Y-Z manipulate coupled with a computerized numerical control while scabbling. We have observed not only active spalling on the concrete surface but energetic scattering of laserproduced debris when scabbling on high-strength concretes. It indicates the need for a device capable of collecting the laser-produced debris. We newly designed and manufactured dust collector coupled with cylindrical tube to prevent scattering of laser-produced debris into ambient environment. The collecting system was evaluated by estimating the collecting efficiency for laser-produced debris while scabbling. The collecting efficiency was calculated on the basis of the information on the mass loss of concrete block after laser scabbling and the mass of collected debris in a container. The collecting efficiency was found to be over 85%.

그라디오러스에 발생하는 바이러스병을 포장에서 조사한 결과 이 병율이 이었다. BYMV는 명아주에 엽맥괴사병징, 강남콩에 심한 모자익 병징 그리고 잠두에 모자익 병길을 일으켰다. CMV는 명아주에 국부병반, 담배와 오이에 모자익 병징을 일으켰다. 분류 동정된 두 바이러스는 모두 복숭아 혹진딧물에 의하여 전염되었다. 바이러스를 순화하여 흡광도를 측정한 결과 두 바이러스 모두 260nm에서 최고의 흡광도를 나타내었다. 한천내확산법을 이용한 항혈청과의 반응 결과 SDS를 처리한 BYMY와 CMV는 각각 그 바이러스의 항혈청과 뚜렷한 반응대를 형성하였다. 바이러스 입자의 진자현미경검경 과파 BYMV는 길이가 750nm였으며, CMV는 직경이 30nm이었다.