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Japan Plans To Scrap Nuclear Plants After 40 Years
An anonymous reader writes with this news as carried by the San Francisco Chronicle: "After the nuclear meltdown of the Fukushima plant, 'Japan says it will soon require atomic reactors to be shut down after 40 years of use to improve safety.' If, however, a nuclear plant is deemed still safe it may continue operation."
It'll be interesting to see if Gen 3+ and Gen 4 nuclear reactors will be allowed longer terms of lease, given that they have less parts to fail and more passive saftey systems. I think that nuclear could really be a keystone of Japan's nuclear energy future. That, and the Japanese have done research on how to extract uranium from the sea after Uranium prices spike in the future once easily mineable resources become exhausted. If we don't get breeders or thorium running, Japan has done the research.
http://www.jaea.go.jp/jaeri/english/ff/ff43/topics.html
Japan's only major energy resource is the sea. And the sea has enough Uranium to keep Japan ticking long after their population dwindles away due to their low birth rate.
First lets establish the obvious in that safety isn't a binary condition, it's a continuum.
This needs to be expanded on. Safety is not only a continuum but it's an ever changing continuum as new standards for what is deemed "safe". I work at a plant which is quite unique around the world. It's unique in that we've never had a death on site. Does that mean we're safer than other sites? Hell no.
Looking back at our history we had scaffolders holding onto the top of a tower with one hand with no safety harness on and with the other mounting a scaffold pole. We had a really old control room with a large window facing the plant less than 10m away. We've never had an incident that has damaged that building but that doesn't mean it is safe. We had to build a giant cement bomb proof bunker for our new control room and more recently move all day staff off site.
When the plant was built there was no emergency shutdown system. Now 50 years later we still use some of the original kit but with a number of SIL rated shutdown systems in addition to the modern control system. Not to mention 50 years worth of changes in process design, check valves and relief valves in critical positions, a massive relief flaring system, etc.
That point I am trying to make is that if you build a site and maintain a site perfectly to the standards of the day it was designed then eventually it will be deemed unsafe simply because you're ignoring years of changes in standards and lessons learnt from the process safety industry.
40 years ago you weren't held liable for not putting up a wet floor sign either.