What could the Japanese have done to have been better prepared for the tsunami?

[Broomstick]

@Magiver

I disagree. It’s not a function of money but of planning. They built an infrastructure on the premise of a lesser event. The sea walls were too low and some of the emergency shelters were too low. People went to “high ground” as instructed and died because the water exceeded it.

As mentioned - this event exceeded the worst-case predictions. If this event had not exceeded expectations the sea walls would have been high enough, the shelters dry, and we’d all be applauding Japanese engineering while watching a tsunami crash against concrete and steel barriers on YouTube.

They did the best they could with what information and resources they had. Unfortunately, Mother Nature played a trump card.

As far as the nuclear power plants go, they didn’t have a tertiary level backup.

Actually, they did:

1. Normal cooling
2. Diesel backup
3. Battery back up to the diesel generators - 8 hours worth which, by the way, functioned just fine. For 8 hours.

Now, I agree that more backup would have been better, and better placement of the diesel generators would have been better. There is considerable room for improvement here, I’m just pointing out that there WAS tertiary backup.

MOST powerplants of that sort are not situated in tsunami-risk areas. MOST of them have 96 hours of battery backup. We can’t change the location’s tsunami risk, but they should have made the safety modifications more Mark 1’s received after Three Mile Island. THAT someone should be held culpable for.

They should be built to a higher level of redundancy.

Agreed. Apparently, tertiary backup isn’t sufficient for a nuclear power plant.

I certainly don’t understand why they vented hydrogen gas from the inner core to the outer core structure. They just created a very large bomb in the process of doing so. All of that can be addressed on an engineering level.

The reason for venting the hydrogen is to prevent an explosion from breaching the primary containment vessel. Better to vent it into the building at the risk of the outer building going boom than keep it bottled up until the main vessel blows. Although the explosions we witnessed were powerful and serious, what they blew up was an ordinary building with little if any radioactive stuff to spew around. If the primary reactor vessel had blown up it would have been much more destructive, as it would have required greater pressures to do this, and there would be MUCH more radioactive gunk thrown around.

In other words, as nasty as the recent explosions were, they were the lesser of two evils. By allowing that to occur they limited the damage. Believe it or not.

[Novelty_Bobble]

@Magiver

I disagree. It’s not a function of money but of planning. They built an infrastructure on the premise of a lesser event. The sea walls were too low and some of the emergency shelters were too low.

Well I did say it was money and logistics (which as they become more complicated, also become more expensive)
In any case, higher sea walls and shelters and different building designs cost money. People would be inconvenienced if we were to direct them exactly where and how to build, and how to live their lives to minimise tsunami risk.

All of these things are balanced as we consider what might befall us.

[Really_Not_All_That_Bright]

@Susanann

+1 Duh!!! Yeah!!! Don’t live on the water, or you might get wet. Even a child should understand this simple principle.

Ditto for those stupid people in New Orleans who build BELOW sea level - even more stupid.

Half the world’s population lives near sea coasts. It’s where the best arable land is, and people go where resources are. This is especially true in Japan, where rice and seafood are staples.

If you’re going to tell people they shouldn’t live in places where bad things might happen, you’d better evacuate the US. Can’t live on the eastern seaboard because of hurricanes. Can’t live in the Mississippi delta because of flooding. Can’t live in the plains states because of tornados. Can’t live in California because of earthquakes. Can’t live in the Midwest because of blizzards. Can’t live in Hawaii because of earthquakes and cyclones.

We should all just live in Britain.

[Mama_Zappa]

@don_t_ask

Moved Japan somewhere else?

I think the earthquake just did that! :eek: :(.

That said: interesting thread; I think that sometimes, it’s not possible to do anything more to make things safer. The Japanese did a pretty good job already; most other places would have been even more devastated.

[Machine_Elf]

@Broomstick

The reason for venting the hydrogen is to prevent an explosion from breaching the primary containment vessel. Better to vent it into the building at the risk of the outer building going boom than keep it bottled up until the main vessel blows. Although the explosions we witnessed were powerful and serious, what they blew up was an ordinary building with little if any radioactive stuff to spew around. If the primary reactor vessel had blown up it would have been much more destructive, as it would have required greater pressures to do this, and there would be MUCH more radioactive gunk thrown around.

In other words, as nasty as the recent explosions were, they were the lesser of two evils. By allowing that to occur they limited the damage. Believe it or not.

OK, I understand why hydrogen was vented out of the containment building. But why wasn’t it vented out to the sky, instead of into the attic?

[Broomstick]

It might be they were trying to do so, but were unable to vent it outside fast enough? After all, those walls looked pretty solid, there might not have been sufficient opening to the outside to prevent the problem. Remember, too, hydrogen is lighter than normal air, it would have all been up at the TOP of the building, which means only roof-level vents would have cleared it out - ground level doors and windows wouldn’t have been of any help.

So… maybe add “more roof vents” to the list of new safety items.

[JoelUpchurch]

Face it. The Japanese did a pretty good job. Most other places would have had death tolls over 100,000 and some places would have been bury the bodies and repopulate. The short warning on the Tsunami made a huge difference. If there had been an hour’s warning before it made landfall, the death toll would have been far lower.

[Magiver]

@Broomstick

It might be they were trying to do so, but were unable to vent it outside fast enough? After all, those walls looked pretty solid, there might not have been sufficient opening to the outside to prevent the problem. Remember, too, hydrogen is lighter than normal air, it would have all been up at the TOP of the building, which means only roof-level vents would have cleared it out - ground level doors and windows wouldn’t have been of any help.

So… maybe add “more roof vents” to the list of new safety items.

You don’t vent hydrogen into a building as a design safety feature.

[lisiate]

@kenobi_65

10 times. Each increase of 1.0 on the scale is a ten-fold increase in the amplitude of the earthquake.

More like 32 times as the Moment Magnitude Scale is based on 10 to the power of 1.5. From wikipedia’s page on Moment magnitude scale

As with the Richter scale, an increase of one step on this logarithmic scale corresponds to a 10^1.5 ≈ 32 times increase in the amount of energy released, and an increase of two steps corresponds to a 10^3 = 1000 times increase in energy.

What else could Japan have done to prepare?

Well having compatible electrical grids on both sides of the country would have helped cover the power generation losses faced after the earthquake/tsunami.

[Broomstick]

@Magiver

You don’t vent hydrogen into a building as a design safety feature.

You do if the consequences of NOT doing so is worse than doing so. As I said, it was the lesser of two evils, I never said it was a good thing.

Also keep in mind that similar outgassing of hydrogen happened at TMI and there wasn’t an explosion in that case, so it might have seem a reasonable risk at the time. In hindsight, maybe not so much.

[Magiver]

@lisiate

Well having compatible electrical grids on both sides of the country would have helped cover the power generation losses faced after the earthquake/tsunami.

OH MY GOD. They have 2 different electrical grids!!! That’s insane.

On a side note, when we tore down our old power plant and switched to the larger plant down the road we built a bunch of peak-use generators to fill demand gaps. They take 6 months to build. they should have started building those last week.

[lisiate]

Isn’t it? I love the reason - in 1895 the Tokyo company bought its 50 Hz plant from Germany’s AEG . In 1896 Osaka bought 60 Hz gear from General Electric.

[Kent_Clark]

The Japanese earthquake was a 9.0 and the tsunami wave reached 30 feet.

But the 2004 Indian Ocean earthquakewas a 9.1 and the tsunami waves reached 80-100 feet.

The point being, we can make things bigger and stronger, but so can nature.

[TokyoBayer]

Japan did pretty well, but as pointed out by kuniluo, they had a smaller tsunami to deal with than in the 2004 Indian Ocean quote. If you think of the difference between 30 feet (three stories) and 80 to 100 feet (eight to 10 stories), then you can see how there would have been a much higher death toll in Japan if there was been the same scale of tsunami. You also can’t really compare a developed country to an underdeveloped one.

For the question of if the backup system at the reactors was sufficient, I’ll try to be brief so that yet one more thread doesn’t become derailed into the reactor mess. Having multiple backup systems that fail at the same cause means that you do not have back up systems.

Also, while the it’s obvious that the system did not withstand a 9.0 quake, I don’t know how much less of a quake it would have taken in order to have been unaffected.

It’s not practical or economically possible to build enough sufficient structures to protect an entire nation from tsunami, so there will always be fatalities. Zero is an impossible target to shoot for.

For the question of time before the tsunami, the alerts on TV come up pretty quick. However, when every minute counts, people who live or are in low lying areas need to know that they must be ready to flee, even before the alert. I was in Tokyo, hundreds of miles away, and there was no doubt that it was a strong earthquake. Having your own plan is paramount, and no amount of government preparation will eliminate the requirements of individuals for their own safely.

The prefecture and local governments are getting better at disaster prevention training and information, but this is a field which could be stressed more. We just went to an event at a local fire station, and there stations where you could use fire extinguishers and practice making calls to report fires. The calls were very good practice for children, and it’s drills like this which can help people think more, but again, preparation is something which comes down to individuals.

Japan has a rapidly aging population, and more elderly people living by themselves. This is a problem which will not quickly go away.

[Snarky_Kong]

@lisiate

More like 32 times as the Moment Magnitude Scale is based on 10 to the power of 1.5. From wikipedia’s page on Moment magnitude scale

You’re talking about two different things. The Moment Magnitude scale is a log scale. A 9.0 has 10 times the ground motion of an 8.0. However, it takes about 32 times the energy to cause 10 times the shaking.

[lisiate]

But isn’t ‘ground motion’ measured on one of the intensity scales (Modified Mercalli, Shindo Scale etc) which vary by location/distance from the epicentre?

Whereas the Moment Magnitude measures the Magnitude of the quake.

[Snarky_Kong]

The ground motion for magnitude quantification is supposed to be measure from a standard distance from the epicenter. I believe also on rock, not soil, but I’m not positive.

Intensity scales are based upon polls of people in the area and are most useful in guessing at the scale of pre-instrumentation earthquakes by way of written record. There’s obviously some correlation between intensity and ground motion, but they’re not the same. Humans sense motion differently than you would measure ground acceleration or velocity.

[lisiate]

Fair enough, you’ve fought my ignorance. So an increase of 1.0 on the Moment magnitude scale represents almost 32 times the energy but only 10 times the ground motion?

[Snarky_Kong]

@lisiate

Fair enough, you’ve fought my ignorance. So an increase of 1.0 on the Moment magnitude scale represents almost 32 times the energy but only 10 times the ground motion?

A 10 times increase in ground motion at a standardized distance (and stratigraphy, I think) from the epicenter, yes.

Makes making sense of “earthquake X was 300 times stronger than earthquake Y” difficult.

[lisiate]

No wonder the media are stuck in the Richter ages…