Tuesday, May 24, 2011

Mainichi English: "Agency gears up to retrieve device fallen inside Monju reactor"

Ah, the horror, the horror....

Monju is a fast breeder reactor that uses sodium as coolant, which catches on fire on contact with air. It uses MOX-fuel.

3.3-tonne, 12-meter "In‐Vessel Transfer Machine" fell into the reactor vessel on August 26, 2010. The manager at the plant in charge of fuel exchange committed suicide in February this year.

From Mainichi Shinbun English (5/24/2011):

TSURUGA (Kyodo) -- The Japan Atomic Energy Agency began preparatory engineering work Tuesday to set up equipment it will use to retrieve a device that fell inside the vessel of its prototype fast-breeder reactor Monju in Fukui Prefecture last August, agency officials said.

The agency aims to collect the cylindrical 3.3-ton device together with part of the vessel's upper lid by mid-June to get the reactor back to normal by autumn, allowing the resumption of a test run of the 280,000-kilowatt prototype, the officials said.

But it is unknown when the test run will begin at the unit on the Sea of Japan coast as Prime Minister Naoto Kan has declared a review of Japan's basic energy plan following the nuclear accident at the Fukushima Daiichi power plant caused by the March 11 earthquake and tsunami.

After the Aug. 26 accident, the agency tried in October to recover the device used in fuel exchange but failed as it had become misshapen, preventing its retrieval through the upper lid.


Anonymous said...

Thank you for your important work. But this 'latest' mistake has actually been going on since August 2010? How many other reactors have similar stories?

areyoume said...

Of course you know the person in charge of this unit etrieval committed suicide in February this year?

Anonymous said...

Wait, what?

Anonymous said...

Captcha for my previous comment: doses. How very appropriate.

Anonymous said...


Press Release Information Nuclear and Industrial Safety Agency (NISA),
Ministry of Economy, Trade and Industry (METI)
Deformation of the In-Vessel Transfer Machine in the Japan Atomic Energy Agency Prototype Fast Breeder Reactor “Monju” (Results of visual inspection corresponding to the “in-vessel transfer machine falling event”that occurred on August 26, 2010)

Anonymous said...

Press Release Information Nuclear and Industrial Safety Agency (NISA),
Ministry of Economy, Trade and Industry (METI)
Deformation of the In-Vessel Transfer Machine in the Japan Atomic Energy Agency Prototype Fast Breeder Reactor “Monju” (Results of visual inspection corresponding to the “in-vessel transfer machine falling event”that occurred on August 26, 2010)


Sal Farruggio said...

So does that mean there is also radioactivity outside the containment vessel, or damage to it? Another nuclear disaster in the making..It must be pretty severe that the guy in charge commits suicide?

Anonymous said...

Robbie001 sez:

One thing a lot of people don't realize is that a LMFBR is one of the few designs that can actually generate an atomic explosion. The fuel core uses highly enriched Uranium so it is easier for the molten mass to go critical in a meltdown.

LMFBR fire concerns



You can read Dr. Richard E. Webb's excellent book "The Accident Hazards of Nuclear Power Plants" as a free trial at this site. He cover the LMFBR short comings in chapter 10.


For those of you who want the LMFBR Cliff notes here we go. LMFBR fuel cores have a much higher energy density they are susceptible to Autocatalytic Reactivity Excursions (ARE). Light water reactor have a negative void coefficient they need water as a neutron moderator in the presence of a "void" their reactivity goes down. LMFBR on the other hand have a positive void coefficient loss of coolant increases neutron activity. In an accident the steel components of the reactor can become so super heated that they cause a Sodium vapor explosion. This explosion can compress the molten fissionable material enough to cause a low order nuclear detonation. As A-bombs go it would be considered a dud at 10,000 pounds of TNT but it would exceed the estimated ability of containment by a factor of ten.

Anonymous said...

We all owe you an extreme amount of gratitude for reporting these last couple of months!!!! Although the data and filtering of news is usually 10 times worse then reported at the time, at the least we are receiving some coverage. Prepare my brothers and sisters we are facing the end time prophecies.

God bless to those with ears to hear and eyes to see!

Jason Zamorano

Anonymous said...

How the heck can a "part of the upper lid" of the containment vessel break away and drop into the reactor? These things are claimed to be nearly indestructible because they are supposed to protect the reactor, right? And what was the result of half the lid missing - did radioactivity get out?
But the most insane thing is, that they actually plan to continue the operation of this plant!! What are they? mad?!

Anonymous said...

oh come on guys you know nuclear power is safe and radiation is as tasty and safe as hydrocarbons mingled chemically with Corexit. Just ask the oysters or any Pacific Ocean sea life (if there are any left alive!)

Anonymous said...

Robbie001 sez:

More Breeder reactor fun facts Monju has all kinds of problems here's a small taste of the costly "4th generation design".

"In the course of preparations to restart Monju, it was discovered by accident, as a result of false alarms, that hundreds of contact-type sodium detectors had not been checked. Also, corrosion of the exhaust duct was left untreated. Problems such as these exposed the sloppy nature of the preparations and the restart date was extended on four occasions. There is no guarantee that other important checks have not been missed. Nor do we believe that organizational issues related to problem response, such as frequent late reporting, have been rectified. Many experienced people have left, giving rise to human resource problems. Under these circumstances it is dangerous to restart Monju. We believe there is a big risk of another accident."


Overview: The Rise and Fall of
Plutonium Breeder Reactors

This covers all the failed breeder programs across the globe.


Anonymous said...

I wonder how many more world nuclear reactors are located right by the sea. The Japanese had Fukishima now this one. How many more such reactors by the sea? In case of an accident such as happened in Fukishima stopping the consequences from spreading world wide is greatly complicated or rendered impossible by such sea side locations. First the radioactive contaminants have ready access to the sea. Once released in to a sea it is virtually impossible to collect these radioactive elements in a cleanup effort. You just spread them world wide Secondly is the danger of tsunami damage being located right near the ocean. Third is
the difficulty of covering them with concrete ala Chernobyl this because of the limited strong terrain on all sides.
Do other such seaside plants exist worldwide in other countries? Locating such plants right by the sea is folly, they should never have been built. These plants should be the first ones`to be immediately shut down on a priority basis. How many more such accidents can we take?

Anonymous said...

Robbie001 sez

@Anon 8:20

Yes most commercial nuclear reactors are based on light water. Their operations rely on vast amounts of water to modulate thermal operations and to moderate fast neutrons into the thermal range in the core. Even if they aren't directly by the sea they are near a large sources of water.



In addition the UK, France and Japan all operate leaky nuclear fuel reprocessing facilities by the sea. Except the leaks are officially called "emissions". The US operated military reprocessing facilities at Hanford, Wash. and Savannah River facility in Aiken South Carolina. Both of these facilities are on the water and both of them have leaks that they were never supposed to happen. The Savannah River facility still operates limited reprocessing operation.


Savannah River reprocessing



BTW, the Chernobyl problem isn't covered in concrete nor is the problem beyond the "stewardship in perpetuity" stage. The impoverished nations responsible for the Chernobyl disaster are still begging for international funds to build a proper sarcophagus so they can wack-a-mole the problem for another century (they hope).


Philippe said...

Some explanations here :


Anonymous said...

The author wrote:
"....that uses sodium as coolant, which catches on fire on contact with air."
According to the science of the day:
Sodium usually does not ignite in atmospheric conditions under 115 degrees Celsius, or without immersion in water.

Anonymous said...

There are two very old and obsolete reactors on the calfornia coastline. They are found to be constructed on seismic faults not detected when built. If they melt down due to seimic activity, they may affect millions of homeowners around them. Very expensive real estate will be worthless. I say this as in america only the rich have the political clout to change things. I hope these rich real estate owners will see the peril of owning things around atomic reactors. The Fukushima reactors melted down within a few hours after the earthquake. Modern man does not have the tools yet to manage this kind of natural disaster. We thought Japan mismanaged their real estate bubble in 1990. We now know how difficult it is first hand to correct a banking disaster and don't fault the Japanese any longer. I sense the same will occure when we eventually have our own Fukushima style disaster. Why wait, do it now.

New anonymous said...

@Anonymous, two up, “Sodium usually does not ignite in atmospheric conditions under 115 degrees Celsius, or without immersion in water.”

Unfortunately, to produce high-pressure steam the sodium coolant circulates at a temperature much higher than 115 C. Note that it is, therefore, also flowing next to water, separated only by pipe walls.

France built one. It caught fire.

These are very nasty and dangerous systems.

Check out molten-salt thorium breeder reactors for an enormous and refreshing contrast.

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