Wednesday, March 16, 2011

NuclearTownHall
The Fukushima reactor disaster resulted from a power outage to backup reactor cooling systems at the nuclear plant. Heroic emergency volunteer crews have been using police water cannons to pump seawater over the reactors, but what they really need is to restore power to emergency backup systems. To that end, power crews have been working steadily to install a new power line to the plant, and are getting closer to achieving that goal.
The operator of Japan's tsunami-crippled nuclear plant says it has almost completed a new power line that could restore electricity to the complex and solve the crisis that has threatened a meltdown.

Tokyo Electric Power Co. spokesman Naoki Tsunoda said early Thursday the power line to Fukushima Daiichi is almost complete. Officials plan to try it “as soon as possible” but he could not say when. _Globe&Mail

BraveNewClimate

Here is more information on the levels of radiation which are present in and around the Fushima nuclear plant:
The status report from the The Federation of Electric Power Companies of Japan (FEPC) is given below:
• Radiation Levels
o At 10:22AM (JST) on March 15, a radiation level of 400 milli sievert per hour was recorded outside secondary containment building of the Unit 3 reactor at Fukushima Daiichi Nuclear Power Station.
o At 3:30PM on March 15, a radiation level of 596 micro sievert per hour was recorded at the main gate of Fukushima Daiichi Nuclear Power Station.
o At 4:30PM on March 15, a radiation level of 489 micro sievert per hour was recorded on the site of the Fukushima Daiichi Nuclear Power Station.
o For comparison, a human receives 2400 micro sievert per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6900 micro sievert per scan.
• Fukushima Daiichi Unit 1 reactor
o As of 10:00PM on March 14, the pressure inside the reactor core was measured at 0.05 MPa. The water level inside the reactor was measured at 1.7 meters below the top of the fuel rods.
• Fukushima Daiichi Unit 2 reactor
o At 6:14AM on March 15, an explosion was heard in the secondary containment building. TEPCO assumes that the suppression chamber, which holds water and stream released from the reactor core, was damaged.
o At 1:00PM on March 15, the pressure inside the reactor core was measured at 0.608 MPa. The water level inside the reactor was measured at 1.7 meters below the top of the fuel rods.
• Fukushima Daiichi Unit 3 reactor
o At 6:14AM on March 15, smoke was discovered emanating from the damaged secondary containment building.
• Fukushima Daiichi Unit 4 reactor
o At 9:38AM on March 15, a fire was discovered on the third floor of the secondary containment building.
o At 12:29PM on March 15, TEPCO confirmed extinguishing of the fire.
• Fukushima Daini Units 1 to 4 reactors: all now in cold shutdown, TEPCO continues to cool each reactor core.

This indicates a peak radiation level of 400 mSv/hr, which has come down to about 0.5 mSv/hr by the afternoon. This ‘spot’ radiation level was measured at a location between Unit 3 and 4. It was attributted to a hydrogen explosion in the spent fuel pool of Unit 4 — but this is still under debate. The radiation level at the site boundary is expected to have been much lower and, to date, there is no risk to the general public. _BraveNewClimate
Much more useful information at the site linked above.

As many as 25,000 Japanese may have died from the combined earthquake and tsunami. It is possible that more people will die from the ongoing lack of electrical power, resulting from the quake and tsunami. Electrical power is crucial to modern life -- but there is no totally risk-free way of generating power. Imagine, for example, if a huge hydroelectric plant had been located near the epicenter of a 9.0 quake. How many people would have died downstream? And so on.

It is likely that the danger to the general public from radiation fallout will be minimal to none. Some danger to the emergency crews who are on-site at the power plant is unavoidable, yet by all accounts the crews were doggedly determined to do whatever they could despite the risks.

That is what is expected from volunteer emergency crews in modern nations such as Japan. They train for such emergencies, and it would be extremely difficult to keep most of these men away from the site of danger at such a time.

What does this tell us about the safety of nuclear power? Clearly the double whammy of a 9.0 earthquake plus a monster tsunami should not be expected to hit most nuclear sites. And yet, there is a clear need to re-think some of the assumptions about backup power and backup cooling systems.

Newer designs with passive "failsafe" backups are assumed to be safer. Certainly if the Obama NRC would certify some of the newer, safer designs, and if the faux environmentalists and dieoff.orgy enthusiasts would get out of the way, the world could become an even safer place.

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2 Comments:

Blogger Michael said...

Other info at http://www.nisa.meti.go.jp/english/

5:37 PM  
Blogger al fin said...

Thanks. Nice source.

5:50 AM  

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