FUKUSHIMA DAIICHI NUCLEAR POWER PLANT, JAPAN —
It’s been almost six years since a major earthquake triggered a meltdown at the Fukushima nuclear power plant. A lot of work has been done to investigate and remediate the site, but there is still a long way to go – especially when it comes to the area directly below the reactor core (an area known as the pedestal). Due to high radiation levels and limited access, it is one of the most challenging areas to inspect and evaluate.
In 2015, some work was performed using a robot that incorporated Inuktun Microtrac™ crawlers. Most recently, Toshiba has been utilizing a specialized Inuktun NanoMag™ crawler to deliver high radiation video and lighting systems into the pedestal area. Check out Toshiba's press release here for a video of the crawler in action.
The standard NanoMag™ was originally designed to visually inspect the top and bottom of PWR nuclear reactors, but it is just a little bit too big to fit through the guide pipe being used to access the pedestal area. Instead, we were able to modify the crawler – making it much narrower – so it could operate in the 10 centimetre pipe, and still maintain its ability to steer. Toshiba acquired the new crawler and integrated their own specialized imaging and control systems.
A report was published in the December 2016 issue of OPTRONICS magazine on the development status of the remote devices used for the survey (link here - note that the survey is in Japanese). Remote visual inspection confirmed that in addition to the dark environment and high radiation levels, steam was also prevalent – greatly reducing visibility. The report describes how Toshiba was unable to install high intensity lighting on the crawler due to size restrictions, but instead developed a mechanism to separate the camera and lighting to prevent halation: light scattering into the steam. Even though the engineers have not yet been able to fully quantify the condition of the pedestal, every new project like this gets them a little bit closer.
The project described above, developed under IRID (International Research Institute for Nuclear Decommissioning) and led by Toshiba, targets the expansion of fundamental technology for the retrieval of fuel debris and reactor internals. The new NanoMag™ based robotic system is one of many new technologies developed to assist with the remediation at Fukushima Daiichi Nuclear Power Station; see here for more information. Inuktun is proud to be able to contribute to the nuclear decommissioning solution at Fukushima, and we look forward to providing more remote systems to assist with ongoing cleanup efforts, and to help prevent future disasters. What industry challenge can we help you conquer? Contact our team today to learn more about the solutions Inuktun can offer!