Fukushima Daiichi nuclear power plant: Was the domestically-produced robot, “Quince,” useful? “Real-action deployment” on site is essential

“Quince” modified for response at nuclear power plants, such as by making the legs longer than before. On the right, in front, is Tohoku University professor Satoshi Tadokoro. At Chiba Institute of Technology in Narashino City, Chiba Prefecture. June 8, 2011. Photograph by Yuka Saito.

“Quince” is a domestically-produced emergency disaster response robot that was finally “mobilized” for measurement of radiation levels and the like at Fukushima Daiichi nuclear power plant. In early August, Tohoku University professor Satoshi Tadokoro, chairman of the International Rescue System Institute, an NPO involved in the development of Quince, gave a lecture at an “IEEE” (The Institute of Electrical and Electronics Engineers, Inc.; headquartered in New York, USA) seminar in Tokyo. Tadokoro said, “Quince was very useful, but in Japan there is no pathway for R&D to commercialization of rescue robots. It is necessary to deploy (at the site of use) and to make it a system that can actually be used.” Quince is a robot under development by an NPO, the International Rescue System Institute (IRS; Kobe City), the Chiba Institute of Technology, Tohoku University and the like. It was modified to perform work inside nuclear reactor buildings. Personnel at the Tokyo Electric Power Company (TEPCO) are in charge of operating Quince, and Professor Tadokoro and others are not allowed to enter the nuclear power plant. Professor Tadokoro reported on the work performed by Quince on June 24, July 8 and July 26. Quince is said to have the world’s best capability of moving through rubble, and can climb steep indoor stairways where the inclination exceeds 40 degrees. Quince’s motion performance is superior to that of “PackBot” (made by iRobot of the U.S.), which was deployed in the Fukushima nuclear power plant ahead of

Quince. Quince reached the second and third floors of a nuclear reactor building, which PackBot was unable to reach. Quince was able to survey the situation by measuring radiation levels and taking photographs. Reflecting back, Professor Tadoskoro said, “By surveying the dose rate and the like, it was possible to obtain fundamental data such as what sort of work should be done and which locations should be plugged up, and that was very useful.”  There were also issues in which the motion performance could not be fully exercised On the other hand, there were issues that remained, in which, due to TEPCO’s requests concerning installed parts, lack of skill of the personnel in charge of operating Quince, and incorrect information on the situation inside the buildings, the motion performance that Quince is actually capable of could not be fully exercised. For the work inside the nuclear reactor buildings, Professor Tadokoro and the others originally proposed to TEPCO a method in which searches would be conducted using two Quinces operated in wired and wireless manners. Due to the fact that it was difficult for wireless communication to reach inside the buildings, the idea was to use a wired Quince as a relay unit to increase that range of wirelessly-controlled motion. However, TEPCO did not agree to the idea. It takes six people (including record-keeping personnel) to operate one Quince, and it was said that the rejection was based on a wish to reduce the number of personnel (who would be at risk of radiation exposure). Up to now, only one Quince (a wired operation type) has entered a building. (Professor Tadokoro) says, “There is a risk that the cables will become tangled, and the motion performance is decreased by a considerable degree.”

In addition, heavy parts were loaded, such as a dosimeter for human use, a water gauge and cables that TEPCO uses on a regular basis, so creative measures were necessary, such as making the legs longer. Professor Tadokoro said, “If you place heavy things on Quince, it makes it prone to falling over on stairs. The nuclear reactor buildings have steep iron stairs that are decades old. The surfaces are smooth and very slippery. We want to bring the center of gravity as low as possible, but we aren’t able to do so.”

The work on June 24, in which a water gauge was supposed to be installed inside the nuclear reactor building for the No. 2 reactor, did not go well because the width of the staircase landing was miscommunicated. It was said that the blueprint provided by TEPCO had the width at 90 cm, but when the actual work was started, it was learned that the width was only 70 cm. (Professor Tadokoro) made his displeasure apparent when he said, “I do not understand why this information was not communicated properly. There is no way that Quince, which is 67 cm (in length of the main unit), can rotate in a 70-cm staircase landing.” About cases in which Quince was turned back after being unable to climb over rubble, Professor Tadokoro pointed out, “A skilled operator would probably have been able to make it climb over that and move upward.” He allowed to be known his frustration at the fact that developers familiar with the operation of Quince were not allowed on site.  Domestically-produced robots: “An organization and budget for deployment are necessary” Almost no domestically-produced robots have appeared in the response to Fukushima Daiichi nuclear power plant. PackBot, made in the U.S., has already been commercialized, and it is said that approximately 4,000 units have been sold. However, Quince has only been used for training on an experimental basis by the Chiba Fire Department for six months. It has not been commercialized, and it is said that Quince falls short of PackBot in terms of reliability. (Professor Tadokoro) says, “There were also moments of chagrin” in the period immediately after the earthquake. This is because the rescue robots that had been researched in Japan were based on scenarios involving collapsed buildings, while the damage from this earthquake was mainly from the tsunami and nuclear power plant. He used every possible means to communicate with disaster-stricken areas in order to make Quince useful for areas other than nuclear power plants, but he could not find a situation in which the robots could be made useful. Professor Tadokoro said, “Research and development have not been done on robots that are useful for dealing with tsunami damage, but from a technical perspective, clean-up of sludge and searches in the ocean would be possible. We must research these from now on.” He also said, “With this earthquake, it has become clear that robots have the possibility of exercising great power in disaster response. First, we must create an organization

that deploys robots, and assign a budget to it.” (By Reiko Oka) August 18, 2011