Last year, TEPCO announced that it was going to build temporary structures over its damaged Fukushima reactors. I derided the temporary shelters as circus tents. Now, it looks as if the tents may be part of a larger worldwide plan. As the World Nulear News reported today in a piece called Shrinkwrapping Bradwell:
The main buildings at the UK’s shuttered Bradwell nuclear power plant are to be sealed in a £20 million ($31 million) ‘weather envelope’ while they await final dismantling.
Bradwell has two 123 MWe Magnox reactors that operated from 1962 to 2002. All nuclear fuel was removed by 2005 and last year the shared turbine hall used by both reactors was demolished, leaving only the primary nuclear buildings.
The structures are not quite as temporary as I had hoped:
By 2015 these are to be sealed in the weather envelope to minimise maintenance effort until work resumes in earnest to finally clear the site – perhaps as late as the 2070s.
It’s all part of a larger strategy:
The long waiting period, called ‘care and maintenance’ or ‘passive storage’, allows time for residual radioactive materials to decay – even to the point when nuclear licences are no longer required. Putting off final dismantling also saves money and allows time for improved methods to develop before the work becomes due. The strategy is known as Safestor.
While I believe that radioactive waste should be left where it is produced, I’m not sure that Safestor provides the kind of security from accidental leakage or intentional sabotage that I would like to see in place. My concerns seem to be supported by another couple of paragraphs in the WNN article:
UK engineering group Mott MacDonald will design the weather envelope for Vinci Construction, which is undertaking the decommissioning work for Magnox Ltd.
The envelope is to be “a weather-tight cladding design” that includes a “passive ventilation system to reduce condensation at the site and remove the need for maintenance activities,” said Mott MacDonald. The chance to reduce the amount of inspection work as well as the number of personnel on site presents a clear opportunity for saving over a potential 60-year period. Mott MacDonald engineers have performed a 3-D scan of the buildings and begun modelling conditions inside for a range of conditions.
Here’s a link to the WNN article: http://www.world-nuclear-news.org/WR_Shrinkwrapping_Bradwell_0102121.html