TEPCO Readies Plan To Bring Reactor Under Control

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."

Comments

Just Unit 1?

[Psx29]

Wonder what they plan to do about Unit 2, 3 and the spent fuel pool in 4?

Re:Just Unit 1?

[Darinbob]

Stretch goals.

Re:Just Unit 1?

[thegarbz]

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:Just Unit 1?

[mug funky]

TMI didn't get hit by a freaking 9.0 earthquake and 14 metre tsunami...

you think perhaps that could cause some damage?

Re:Just Unit 1?

[antifoidulus]

Well, we have the dummy plug, and SEELE is sending us the 5th children so I think everything is going to be A OK!

Re:Just Unit 1?

[Opportunist]

Think again. If that happened, every nuke plant owner would just drop any semblance of security and protection because it's evident that if they fuck up, they won't have to clean up the mess.

No, let them handle it. I want them to spend manpower and time and hence money on the mess. It's the only thing that matters to corporations and the more they suffer, the more their peers will probably invest in security.

Re:Just Unit 1?

[im_thatoneguy]

Didn't hurt that the cooling systems were intact at TMI.

Re:Just Unit 1?

[Registered Coward v2]

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:Just Unit 1?

[dbIII]

If you knew anything at all about that incident you would know it was sheer dumb luck that it happened in a structure designed to withstand strike from a large aircraft from the nearby airport so it was the strongest reactor containment vessel built to that date. That's the reason. The lesson was learned and significant changes were made to later plants and whatever existing plants could be modified. In Japan it's a different situation and a very different design so your incredibly and childishly simplistic view is probably wrong.

Re:Just Unit 1?

[khallow]

I thought once let them suckers sleep in the facility once a month that should teach them. Now I think straight execution after the accident of all management levels except the bookkeepers as they have to control payment of damages should commence. There is no way people can learn (see here) so let them pay at least.

I think as a start, we should ignore people like you. TEPCO management hasn't done anything that warrants "straight execution," for example.

Meanwhile, three TVA nuclear sites survived

[Anonymous Coward]

A disaster just fine. Only one of them had anything resembling an issue, and that was the transmission lines going down, which mean the reactor had to shut down.

Nothing major in danger there.

Yet there's little in the way of coverage out there.

At least the people are getting some attention.

Reasonable first steps

[Animats]

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. 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

[Anonymous Coward]

Humans are not entering the "containment". They are entering the reactor building. Reactor building was damaged - especially the top floods. It was not damaged at the bottom, where the cooling equipment is.

Reactor 1 is being tried first because the building as the least amount of radiation. The robot that went in measured about 40-50mSv/h. This is reasonably low and can be brought down further.

The reactors are not in cold shutdown because there is no water cooling. They *could* achieve cold shutdown quickly by water in faster, but it would not help the situation. They need to repair the recirculation pumps and find the leaks and plug them. They also need to find out if there is any hydrogen in the reactor vessels and to deal with that. These 2 reasons is why cold shutdown mode is very BAD right now - they had to slow down water pumping to prevent pressure from dropping as that could cause air to be sucked into the reactor and hydrogen could burn (explode), if there is any hydrogen there.

Don't second guess them now. They are doing things very carefully.

TEPCO failed at not having prepared for the scenario when the plant suffers complete blackout, including all backups being flooded. That's all. Had they had prepared for this scenario, this would not have happened. Period. Now they are dealing with consequences and I'm certain that plans will now be in place that no nuclear reactor will melt even if they lose all cooling - ie. external emergency cooling will be setup before coping batteries die.

Re:Reasonable first steps

[DerekLyons]

Even at Three Mile Island, it took only about two days to reach cold shutdown.

No, TMI-2 didn't reach cold shutdown until 27 April - nearly a month after the accident.

Re:Reasonable first steps

[Anonymous Coward]

Don't second guess them now. They are doing things very carefully.

How dare you try to stop me from being an overly critical armchair nuclear physicist! Who are you to curtail my freedom of speech? Some hoity-toity reactor expert I'd suppose?? Why don't u take off ur white coat and roll up your sleeves like the rest of us? .. oh, not willing to get ur hands radioactive I suppose?

I thought this was a democracy? I'd suppose ur one of them neo-fascist high-folutin Republican extremists? Harry S Truman would've sorted u out good proper like!

Re:Reasonable first steps

[Idou]

That's all? So TEPCO did not falsify safety inspection records, cover-up a defective reactor, use the yakuza to get expendable workers, continue on with a foreign journalist QA session even without the foreign journalists, or make numerous blunders immediately after the tsunami to put us into the current situation ?

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:Reasonable first steps

[mvdwege]

No, TEPCO failed because they relied on a design that requires active input to stay safe. Any measures you think of to improve safety for such a design come down to security by 'Allow by default' and closing holes after exploits. Since it is impossible to keep up with all possible circumstances, this means the design is unsafe.

Mart

Re:Reasonable first steps

[AmiMoJo]

Can we get some objectivity please? TEPCO are far from blameless but equally a bunch of links to blogs, forums and YouTube videos are not all that convincing either. Expendable workers? This isn't China.

The flaws that led to this disaster are not limited to TEPCO or Fukushima Daiichi. The tsunami defences which failed were based on government projections of the most severe waves that would ever be encountered, and they were inadequate. TEPCO built them to what was considered a safe standard, but the the best experts on earthquakes and tsunami in the world got it wrong.

If you didn't notice these flawed assumptions also resulted in 25,000 people being killed. TEPCO made mistakes, some of them should have been preventable and some of them I think it is fair to say were due to people having to react to a difficult situation with incomplete information under a great deal of pressure.

Re:Reasonable first steps

[Magada]

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.

Re:Reasonable first steps

[Kyusaku Natsume]

The tsunami got in from the south side that is closer to the sea. It ripped open the door to the turbine building in front of unit 4. They had a previous study that suggested improved tsunami defenses but it was ignored. The dikes for the port were also built has a tsunami defense, but obviously, they consistently underestimated the risk. In top of that, the whole island sunk 75 cm after the quake, making even more inadequate any tsunami defense they had. Also, Fukushima had in march 12th the only dam failure caused by the quake, so that meant that roads and emergency services had another crippling emergency in top of the quake and tsunami. At the time, Fukushima Daiichi was still a lingering emergency, they were more worried about Fukushima Daini.

TEPCO published details about the improved tsunami defenses that they will build for Kashiwasaki Kariwa NPS; I have almost no doubt that the same method was proposed in their internal investigation for improved tsunami defenses for Fukushima Daiichi. The expense would have been far less than 100 million dollars, a pittance for the budgets that commonly handle utilities.

they failed more

[YesIAmAScript]

TEPCO failed at not having prepared for the scenario when the plant suffers complete blackout, including all backups being flooded. That's all.

That is not all.

They had 8 to 24 hours (I forget) to bring and connect additional power generators or charged batteries to the site before the existing batteries failed, but they didn't do it despite knowing what the stakes were.

They failed to vent the hydrogen from the reactor buildings. They thought to vent the vessels to the buildings but didn't vent the hydrogen from the buildings. This lead to significant avoidable additional damage from explosions and probably raised the amount of radiation released to the environment.

Re:they failed more

[Anonymous Coward]

Um, the buildings were constructed without external vents. So at the time of the earthquake, it was not avoidable. Now, whether they should have foreseen this scenario and installed external venting... Also, you realize that every road for 100 miles around had been trashed by an 9+ magnitude earthquake? TEPCO should be second-guessed on many levels, and the lessons applied to every nuclear power management agency on the planet, but please try to keep it real.

That's the US approach and not universal

[dbIII]

In other places operators are expected to know the plant, take years before they are promoted to be operators and they are paid accordingly. If somebody is going to have to make quick decisions that can cost or save millions in production or repairs you want them to know what they are doing. At one time I was an engineer backing up the operators in a steel rod rolling mill but I did not have the Godlike understanding assumed by the poster above and the operator that had worked in every part of the mill for years before getting in that seat was most definitely the one calling the shots. I could change things all I liked to make good or crap steel rod but if I suggested anything that would endanger the gear it would be made very clear that I was not the boss.

Which Seele Re:Just Unit 1?

[fritsd]

I shudder at the thought of the end result of Kamagurka and Herr Seele draw/paint/act/whatever about the Fukushima accident... intriguing though....
Or maybe I have my cultural references mixed up again.