Faulty thermometer again

February 14, 2012

TEPCO: No.2 reactor thermometer likely broken

http://www3.nhk.or.jp/daily/english/20120214_27.html

The operator of the damaged nuclear power plant in Fukushima suspects a thermometer that has been showing rising temperatures in one of the reactors is malfunctioning.

The thermometer at the bottom of the Number 2 reactor showed a reading of 251.2 degrees Celsius as of 11 AM on Tuesday, while the 2 other thermometers showed temperatures of around 31 degrees.

On Monday afternoon, the thermometer in question showed a reading of more than 200 degrees.

Earlier on Monday, Tokyo Electric Power Company passed an electrical current through the thermometer and found that resistance was about 1.7 times the normal level.
TEPCO says this happens when a wire is broken.

The operator denied the possibility of the reactor heading toward criticality again, as it has not detected any radioactive xenon, which would be generated from continuous nuclear fission.

It says it will continue to circulate water through the reactor and carefully monitor the situation.

The Nuclear and Industrial Safety Agency has instructed TEPCO to measure the temperature in different ways and submit a report by Wednesday.

Early last week, TEPCO said the thermometer read about 45 degrees on January 27th and that it rose to 71 degrees about 10 days later, although the 2 other thermometers continued to indicate about 45 degrees.