TEPCO Readies Plan To Bring Reactor Under Control 116
Kyusaku Natsume writes "TEPCO has released details of their plan to bring Unit 1 of Fukushima Daiichi under control, to improve the working conditions inside the reactor building of this unit and install a new cooling system. From the success of this operation maybe we will know how they will address the emergency in the remaining damaged nuclear reactors."
Reasonable first steps (Score:5, Informative)
That's just the very beginning - hook up an air filtration system so humans can briefly enter the containment. Then try to hook up a water level gauge for the reactor pressure vessel, so they can actually tell how much of the core is uncovered. Then they can think about what to do next.
All this work is taking place in partially collapsed buildings where explosions have destroyed the structure. Ordinarily, one would bring in big cranes with grabs and start removing debris. But they can't do that.
The situation remains dangerous as long as there are still many red blocks on the JAIF's status chart. [jaif.or.jp] Note that reactors 1,2, and 3 still have not reached cold shutdown, where the reactor core is below the boiling point of water, all steam has condensed to water, and pressure in the reactor vessel is down to one atmosphere. All the ad-hoc cooling measures aren't enough to get the core temperature down. Normal time to cold shutdown for a GE Mark I reactor is about a day. Even at Three Mile Island, it took only about two days to reach cold shutdown.
Re:Reasonable first steps (Score:5, Informative)
No, TMI-2 didn't reach cold shutdown until 27 April - nearly a month after the accident.
Re:Just Unit 1? (Score:4, Informative)
I have never seen an industrial plant of any kind where operators are not ruled by engineers with deep knowledge of the process. Operators are button pushers and bring units into certain positions, but it is ultimately the decision of qualified professional engineers who decide on what operating point to bring a unit to, who diagnose why a unit isn't behaving exactly as predicted, and when the shit hits the fan, if they can then they go running into the control room providing live technical support.
This can be taken to extremes and I've even heard of Russian oil refineries who's operators aren't allowed to make any changes without authorisation unless an operating envelope is breached. There are few if any places where operators have true autonomy as to how to run their plants.
Re:Reasonable first steps (Score:5, Informative)
What a relief . . . here I was thinking TEPCO would become the poster child of the part of Japanese society that remains corrupt, arrogant, and incompetent. Good thing they have apologists like yourself . . .
Re:Just Unit 1? (Score:5, Informative)
I have never seen an industrial plant of any kind where operators are not ruled by engineers with deep knowledge of the process. Operators are button pushers and bring units into certain positions, but it is ultimately the decision of qualified professional engineers who decide on what operating point to bring a unit to, who diagnose why a unit isn't behaving exactly as predicted, and when the shit hits the fan, if they can then they go running into the control room providing live technical support.
This can be taken to extremes and I've even heard of Russian oil refineries who's operators aren't allowed to make any changes without authorisation unless an operating envelope is breached. There are few if any places where operators have true autonomy as to how to run their plants.
You've obviously never seen a nuke plant in operation. Their operators aren't "button pushers;" rather they have an in-depth knowledge not only of the physical operation of the plant but the theory as well. They complete years of training and retraining, and in many cases they are engineers as well. They run the plant with the support of the engineers responsible for the various systems. When a problem occurs, the systems engineers do help with the diagnosis, but as part of the operations team, not as some sort of all knowing overseer.
There are few if any places where operators have true autonomy as to how to run their plants.
One of which is a nuke plant. In fact, no one can enter the control room without the operator's permission; for in the control room, they are the ultimate decision makers, very much like the crew on an aircraft.
Re:Reasonable first steps (Score:5, Informative)
Oohh. Mistakes were made. I see. Well that makes it all better, then, doesn't it?
The tsunami defences which failed were based on government projections of the most severe waves that would ever be encountered, and they were inadequate.
There are no tsunami defenses at Fukushima Dai-ichi. Nothing failed because nothing was there. The plants were built too low, the dike which protects against typhoon-generated waves was obviously not enough, but it did not fail, it's still there, as useless against tsunamis as it ever was. Oh, it may have added a bit to the height of the wall of water that struck the NPP.
Had the plant been built above the historical high water mark for tsunamis in that area, nothing would have happened. It was not, because adding elevation means bigger, more expensive pumps for an idiotic design which uses open-circuit seawater cooling for the primary (and only) core coolant loop.