Grossman: There is issue at Japan nuke

Here is another perspective on this, from Scientific American. See if you can line up the facts from the two different articles.

Critters:

I just got Karl Grossman on the phone — one of the leading anti-nuclear authors and professor of journalism at SUNY-Westbury. He has been following the situation at the Fukushima nuclear power plant described in the post below. Here is my understanding of the situation after our conversation.

Courtesy of the Nuclear PR Department

When the quake happened this morning, both main and backup power went out at the Fukushima plant. The power runs pumps that circulate water to keep the reactor core cool. Whether the plant is in operation or not, the core must be kept cool. Once water stops circulating, operators have between 15 and 30 seconds before a meltdown begins — even if they get the reactor under control. That core has to be cooled at all times. So problem one is that the batteries have just eight hours of time, and that was a while ago.

A meltdown would inevitably cause a massive radiation release. Hence, I learned today that a light water reactor (the most common kind used commercially) is always between 15 and 30 seconds away from a meltdown.

Next problem is that there is a radiation leak inside the containment structure. He does not know the source of the leak, but it could be from the primary or secondary loop (a light water reactor has three loops that cool the core; the first and second are radioactive; the third is not supposed to be).

So they are venting radioactive vapor into the atmosphere to keep the pressure down. He believes workers are getting exposed to radiation.

“Now they are venting. There is so much radioactivity, and they’re trying to keep the water going,” Grossman said. “The challenge is to get the water flowing to cool down the reactor core. If it doesn’t you’re going to get damage to the fuel rods. Unless you’re cooling the core with water, it will go haywire,” which is a polite way of saying meltdown.

This would be called a loss of coolant accident — one of several major types of nuclear accidents that are possible.

The plant operators did what’s called a SCRAM maneuver and that was successful. SCRAM is shorthand for ‘safety control rod axe man’, named for one of the first nuclear pile experiments where a guy really was poised with an axe over a piece of rope that he was told to chop in a hurry if given the word.

“But there is extra radiation inside the containment structure and they have not explained why.”

To be continued. If you see news updates, please post them into the comments area. We are all citizen journalists now. Thank you.

–ef

6 thoughts on “Grossman: There is issue at Japan nuke”

  1. The region had a magnitude 7.2 temblor Wednesday in almost exactly the same area. Typically, with any large earthquake, there is about a 5% chance that such a quake is a precursor of a larger quake.

    http://www.latimes.com/news/nationworld/world/la-sci-japan-earthquake-20110310,0,2161671.story?track=rss&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+latimes%2Fmostviewed+%28L.A.+Times+-+Most+Viewed+Stories%29

    I read somewhere else (cant find the link now) that there was also 2 other magnitude 6 precursor quakes before the main one, thats 3 precursor earthquakes above magnitude 6 – from my limited understanding that is pretty unusual… ( the warning may have saved lives ) but it was on the fault line where there has been almost no siesmic activity for several decades..not the main Tokyo Nankai Trough fault they were expecting ( article below from 2009)

    http://www.bloomberg.com/apps/news?pid=newsarchive&sid=a1lfJ5sHyvCQ

    Im not sure its possible for an earthquake on one fault line to trigger an earthquake on an adjacent fault line?

    This is interesting, the Tohoku region where the epicentre of the earthquake was contains the Aomori prefecture, site of an opposed Nuclear power station ( Rokkashu) ‘ In June 2008, several scientists stated that the Rokkasho plant is sited directly above an active geological fault line that could produce a magnitude 8 earthquake’ It isnt on the list of affected power stations though…

    http://en.wikipedia.org/wiki/Rokkasho_Reprocessing_Plant

    This is an interesting article about Japan and nuclear power

    http://www.stop-hamaoka.com/english/takenouchi-1.html

    Citizen journalist now needs sleep ttfn.

  5. From the Beeb, at 6:36PM EST:

    Japanese authorities have warned there could be a small radiation leak from a nuclear reactor whose cooling system was knocked out by the earthquake.

    Technicians at the Fukushima Daiichi plant are set to release vapour from the unit in question to lower the pressure and prevent a meltdown.

    This carries a risk that a small amount of radioactive material could leak, officials say.

    The government has ordered about 45,000 people to evacuate the area.

    Reports quoted Japan’s nuclear safety watchdog as saying radioactivity levels in the control room of the Fukushima plant were running at 1,000 times normal.

    The watchdog also said radioactivity levels near the plant had risen.

    It was unclear whether the apparent increase in radiation had been caused by the failed cooling system.

    Reports also said that cooling systems had also failed in three reactors at a second nuclear power plant, Fukushima Daini, 11km (7 miles) south of Daiichi.
    Wind factor

    A total of 11 reactors at four nuclear power stations automatically closed when the earthquake hit on Friday.

    The prime minister declared a “nuclear emergency” – under Japanese law, an emergency must be declared if a cooling system fails, if there is a release of radiation, or if there is a dangerous level of water in the reactor.

    Japan’s nuclear safety agency said pressure inside one of six reactors at the Fukushima Daiichi plant, some 270km north-east of Tokyo, was considerably higher than normal.

    Authorities say they are taking wind direction into account when planning the release of radioactive vapour, which they insist would not be in quantities big enough to affect human health.

    “It’s possible that radioactive material in the reactor vessel could leak outside but the amount is expected to be small and the wind blowing towards the sea will be considered,” Chief Cabinet Secretary Yukio Edano told a news conference.

    The reactor at the Fukushima Daiichi power station that triggered the emergency alert was the 40-year-old Reactor 1, one of six on the site.
    Continue reading the main story

    AFFECTED POWER PLANTS

    – Onagawa – all three reactors shut down automatically
    – Fukushima Daiichi – reactors 1,2 and 3 shut down automatically; reactors 4,5 and 6 were not in operation; reactor 1 was not cooling as expected
    – Fukushima Daini – all four reactors shut down automatically
    – Tokai – single operational reactor shut down automatically

    The earthquake cut electricity supplies to the power station, triggering an automatic shut-off for the reactors.

    Diesel-powered generators kicked in to provide enough power for cooling and other basic functions.

    But it is understood that at least one back-up generator failed, so causing the cooling system to malfunction.

    Reactors 1, 2 and 3 automatically shut down when the magnitude 8.9 quake shook the plant, while reactors 4, 5 and 6 were not in operation as they were undergoing scheduled inspections.

    The reactors are Boiling Water Reactors (BWR), one of the most commonly used designs, and widely used throughout Japan’s fleet of nuclear power stations.

    Heat is produced by a nuclear reaction in the core, causing the water to boil, producing steam. The steam is directly used to drive a turbine, after which it is cooled in a condenser and converted back to water. The water is then pumped back into reactor core, completing the loop.

    In total, the country has 55 reactors providing about one-third of the nation’s electricity.

    Full text @ http://www.bbc.co.uk/news/world-asia-pacific-12720219

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