Then and Now
The basic design of Fukushima I dates from the late sixties. That is almost 45 years ago! A review of the improvements in other technologies since then makes one instantly realize how much the technology must have improved - but to many of the general public, nuclear power remains mysterious and menacing. With the exception of France, Korea, India and China, countries discontinued most of their nuclear power development programs from the late 70s.
The industry convention is to group reactors into Generations I, II. III and IV. Simply put, "I" represents the prototypes built until the mid 60s; "II" the plants built from then until the mid 90s (i.e. most plants in current operation) and "III" the "new versions" incorporating improved fuel technology, thermal efficiency, passive safety systems and standardized designs. Generation "IV" are design concepts and are therefore beyond the scope of this discussion.
The overriding issue is safety. In this context it is worth examining the four Westinghouse AP 1000 plants currently under construction in China. This Generation 111+ design employs a passive cooling system.
Crucially, external AC power is not required for maintenance of cooling in the type of emergency experienced at Fukushima or Three Mile Island. In addition, water cannot drain from the spent fuel pool even if water is lost. The design was approved by the Nuclear Regulatory Commission in 2005 and is currently under assessment by the UK office for nuclear regulation.
With the merciful absence of any serious long term threat to human health from the incident (so far!), governments should finally give the green light for replacement and expansion of our Generation II plants.