Saturday, March 3, 2012

#Fukushima I Nuke Plant Reactor 2 RPV: 2 More Thermocouples Gone Bad

Now, there are only 15 thermocouples left on the Reactor Pressure Vessel of Reactor 2 that are more or less working. Before the accident, there were 31 thermocouples on the RPV monitoring the temperatures, according to Yomiuri Shinbun (3/3/2012).

The thermocouple at the RPV bottom at 0 degree, 69H1, has already been declared failed (after TEPCO tested it...), and now 69H2 at 135 degrees is considered failed, as DC resistance is too low for a properly functioning thermocouple. Now, the thermocouple at 270 degrees, 69H3 is the only one measuring the temperature at the RPV bottom.

The other thermocouple gone bad is 69F3 at the junction of skirt supporting the RPV at 270 degrees.

According to Yomiuri, TEPCO plans to install new thermocouples by the end of July. No information about how.

From TEPCO's handout for the press, 3/3/2012 (reference, in English):


1 comments:

Atomfritz said...

"According to Yomiuri, TEPCO plans to install new thermocouples by the end of July. No information about how."

They actually don't know how to do this.

On the physicsforums Tsutsuji translated into English the according parts of the March 2nd Tepco report that is available in Japanese only.
Reading this, you'll note the big number of overwhelming difficulties that have to be solved before to be able to install new instrumentation.

Read the translation here:
First part: http://www.physicsforums.com/showpost.php?p=3795578&postcount=12465
Second part: http://www.physicsforums.com/showpost.php?p=3796935&postcount=12485

After reading this, I believe Tepco's time schedule is just wishful thinking.

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