At Fukushima, gensets were underground

[jakeXT]

After the quake, the reactors had automatically shutdown. Off-site power too had snapped. The generators managed to provide power for about an hour when the 10-meter tsunami reached the plant, breached the seawall, swept away the diesel tanks and drowned the generators. This led to a critical condition called "station blackout".

There is high residual heat in the cores even after shutdown, sufficient to boil off 300 tonnes of water every day. So water needs to be pumped in continuously to cool the core. Pumps do this, but they need power. That is why, standby generators are needed.Keeping the generators at low levels has been criticized by experts in nuclear design.

Tepco managing director Akio Komori has admitted that the elevation of the backup generators was a potential issue of inquiry.

Some nuclear plants in the US, have Fukushima type design, but they keep the generators in watertight stalls with 30-centimeter thick concrete walls.

http://timesofindia.indiatimes.com/india/At-Fukushima-gensets-were-underground/articleshow/7741036.cms


ah ... next time...

[NYC_SKP]

1. What a clusterfuck... Really... Below grade generators, fuel tanks swept away.

They DID realize that the were building these in JAPAN didn't they?

On the "Ring of Fire"...

Home of the word "tsunami".

x(

[jakeXT]

2. Maybe they can hire Condi or Mr. known unknowns as PR

[Maine_Nurse]

3. I heard an interesting talk from an energy engineering professor this morning...

regarding the currently operating nuke plants. Not only do they use statistical risk analysis to cut corners, but even the "tsunami-proof" plants that operate in California and other places, really don't make use of all the safety features which are available and instead use some things that look good, but are cheap and not overly effective. His analysis of the tsunami walls around some Cali plants showed them to often be token instead of truly utilitarian. Apparently, depending on coastline sub-surface structure, tides, etc, a relatively small wave could easily either breach or pile up over these 30ft walls.

This wasn't an anti-nuke professor or talk, he simply is for nuke plants only if we actually build them safely instead of saving $$ to do it the way we always have. Although he pointed out that newer designs which are inherently incapable of achieving meltdown or over pressure are very much safer, it was his contention that we've been able to build extremely safe nuke plants since the 60's, but simply refused to spend twice the construction cost to build something that is hundreds of times as safe as what was actually built.

[snagglepuss]

4. The nuclear industry needs to be nationalized so all profits get ploughed

back into creating and maintaining the highest safety standards. For-profit companies cut corners, investing in safety doesn't make money.

[jakeXT]

5. He is right reactors requiring active cooling should be replaced nt