Sendai Reactor Has Condenser Malfunction, Volcano Risk Increases

The only operating reactor in Japan has developed a problem with its condenser system. Detection of conductivity was found in the secondary loop system indicating sea water was leaking from the condenser. In pressurized water reactors of the type at Sendai there is a middle piping loop to transfer heat so that the sea water is never in direct potential contact with the reactor water.

Currently the demineralizer system has been able to remove the salt leaking into the secondary loop. Kyushu power says they will hold the reactor at 75% power until the condenser leak can be investigated. Depending on the extent of the problem they may be able to continue operating or defer repairs until the next refueling outage.

Meanwhile at the nearby Sakurajima volcano concerns for a major eruption have escalated. The Showa vent on the volcano has plugged up with debris and now the volcano is seeing increasing pressure.

“The vent has almost been blocked up, and explosive power is increasing as a result of heightened pressure inside the vent,” said Masato Iguchi, the scientist who heads the Kyoto University’s Sakurajima Volcano Research Center. Iguchi joined the aerial survey undertaken by the Japan Meteorological Agency on Aug. 19 to study the situation.”

The Minamidaki vent area has seen the land expand 16cm on the east and west sides. This change indicates that magma is rising in the Showa vent.

** Update: Dean found a page that explains the PWR condenser units for more in depth go here:


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