SEOUL, Nov. 17 (Yonhap) -- South Korea's state-run atomic laboratory said Thursday it has developed a nondestructive tester for steel that can penetrate a record 80 millimeters and could be used by shipyards and nuclear reactor builders around the world.

   The residual stress instrument (RSI) has 20 millimeters more in penetrating capability compared to the ISIS machine made Britain that has been lauded as having the best performance so far, the Korea Atomic Energy Research Institute (KAERI) said Thursday.

   The RSI uses neutrons made by the 30-megawatt High-flux Advanced Neutron Application Reactor (Hanaro) unit in Daejeon, 160 kilometers south of Seoul, the institute said, adding it employs the diffraction characteristics of neutrons to examine various steel products without damaging the materials being checked.

   "Because the system checks residual stress, it can pinpoint problems that do not show up on conventional examinations, but can lead to minute cracks down the road," KAERI said. These cracks can seriously weaken the strength of products and pose safety issues.

   Once the instrument is used extensively in the field, it could greatly enhance competitiveness and safety for ships, atomic power plants, and other large structures, the lab said.

   The institute said that it has successfully tested the machine to check for weaknesses in welded areas of container ship hulls that are 80 millimeters thick.

   At present, the majority of container ships are 12,000 20-foot-equivalent (TEU) unit vessels, but industry sources expect larger ships to go into operation in the near future.

   Ships that can handle 16,000 TEU of containers need to have hulls that are very thick and can only be checked by RSI.

   yonngong@yna.co.kr
(END)