[LINK] Nuclear power stations.

[Chris Maltby]

>> On Fri, Mar 18, 2011 at 10:14 PM, Kim Holburn <kim at holburn.net> wrote:
>>> No diesel generator just in case!  How did they even start the system up?

> On 19/03/2011, at 11:31 AM, Fernando Cassia wrote:
>> I remember reading that generators were available, but were flooded by
>> the tsunami.

On Sat, Mar 19, 2011 at 12:03:40PM +1100, Ivan Trundle wrote:
> This has been mentioned in a number of reports: on-site diesel
> generation serving the units were mostly crippled by the tsunami: the
> waves were higher than that modelled, and the facility's protective
> barriers were breached.

The backup to the diesels was grid power from elsewhere in the network,
but the earthquake/tsunami destroyed the grid too (oops). The problem
for the improvised backup coolant pumping system is apparently an
inability to generate sufficient pressure to overcome the internal
pressure of the reactor vessel (and to reach the inlet points high up
in the structure).

Diesel backups don't always work under the sorts of loads that a real
emergency generates, and then there is the issue of keeping sufficient
fuel supply to run them until the need is gone which may be a week or
more.

This kind of risk management engineering is very complex and expensive
and there are plenty of incentives to take shortcuts. Then there are
more incentives to cover up the inadequacies when things go pear shaped.

I doubt if we will ever completely understand the sequence of events
that led to this being a very serious incident...

Chris