Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Cybernetics and automation
Keywords: Automation, Cybernetics, Research, Technological developments
Abstracts:Reports and surveys are given of selected current research and development in systems and cybernetics. They include: Interdisciplinary research, Innovations, Formal methods for safety-critical systems, Biocybernetics, Internet access for all, Management cybernetics, Cybernetics and automation, Shrinking the robot.
Cybernetics and automation
Important role for robots in the nuclear Industry.
Robots have undoubtedly proved their worth in many of the diverse applications in which they have been involved. None more than in the nuclear industry where a combination of a dangerous environment for operators and the safety of communities and indeed the whole world produces great challenges.
The decommissioning of nuclear reactors is now an ongoing operation throughout the world as useful and safe lifespans come to an end.
In the UK, for example, engineers have begun to dismantle the irradiated core of Windscale's nuclear reactor. This, we are told, involves a decommissioning scheme costing £80 million. The dangers of carrying out such a scheme without the use of robots would be such that it could well prove impossible. Instead, from a protected control room, engineers can manipulate an £8 million robot that is capable of cutting, shearing and grinding through metal and graphite, by using a bank of television monitors for guidance. Teams of operators are able to use the robotic system to enter the nuclear reactor's Hot Box to retrieve abandoned neutron shield plugs. The plugs which look like a series of innocuous metal rods remain radioactive for some 18 years when Windscale has stopped generating electricity.
The engineers at the reactor site aimed to fill 140 concrete boxes with the radioactive material. The boxes were stacked, three deep, in a special purpose-built store on the site where they could, if necessary, remain entombed for the coming 100 years.
Windscale, which was opened in 1961, is the location for the UK's lead power-decommissioning exercise, which has been designed to show how the nuclear industry can clean up "its own mess". The scheme is being financed by the UK Government, the European Union, and also the nuclear industry itself.
What it is hoped to prove is that the method of "safestore", where old reactors are weatherproofed and left until the radiation levels have reduced to a more manageable level, is not the sole option. In the UK, three old Magnox reactors have been stored in this way. Now if this scheme is a viable one, it will provide a much needed alternative way of decommissioning.
The task before the engineering teams is to remove 1,200 tonnes of immediate and low-level nuclear waste. To do this they have to work from the top of the reactor downwards, that is from the Hot Box, pressure vessel to the core, in what is described as a sequence of "campaigns". It is estimated that this will take some five years to complete. No one has claimed that it could be done without robots or, if it could, provided an estimate of how long it would take. It certainly would not provide the second much needed option for decommissioning.
This project, which is called the Windscale Advanced Gas-cooled Reactor (WAGR), will demonstrate conclusively, we are told, that the technology exists to transform the world's ageing nuclear power stations back to greenfield sites. A report on the use of robots for this work suggests that there is a race to win contracts for the work involved in decommissioning worldwide and particularly in America and Europe, including the countries in the former Soviet bloc, where the work is said to be worth a potential £100 billion. Environmentalists believe that this form of "active" decommissioning of nuclear power stations is the only acceptable option and, now the technology exists, it is the option that they and the nuclear industry itself want to be activated. Obviously the technology has to be effectively demonstrated by the WAGR project and also the decision considered on economic grounds. As far as other countries are concerned we all recognise that the problem of decommissioning is not a local or even a national one, but a global concern. Countries, perhaps, without a "green lobby" may well balk at the cost and find "weather proofing" old reactors a more attractive option. The £8 million robot which controls the removal of an irradiated core in a nuclear power station decommissioning process may not prove to be even a possible option, however environmentally friendly the resulting process has become.
Researchers and developers in automation have provided the technology for the nuclear industry and this is now an opportunity, many environmentalists believe, for the industry to regain public confidence and support.