The highest level of radiation to date has been detected inside the No.1 reactor vessel at the Fukushima Daiichi nuclear power plant.
The utility detected a record level of 10,300 millisieverts per hour. The measurement was taken 20 centimeters above the surface of a contaminated water puddle in the reactor’s suppression chamber.
1,000 millisieverts per hour was detected about 4 meters above the water surface.
Workers are expected to engage in clean-up and other tasks mostly at the 4-meter level, which is raising health concerns.
TEPCO official Junichi Matsumoto said he suspects that a higher radiation level in the No. 1 reactor is caused by more fuel rods melting down than in other reactors.
Published: June 28th, 2012 at 3:54 am ET
- Radiation in No. 1 reactor building “far exceeded expected levels” reaching 700 millisieverts per hour — 500 million becquerels released when opening entrance May 9, 2011
- 4,000 millisieverts per hour detected at No. 1 reactor building June 4, 2011
- Off the Scale: Radiation in No. 1 reactor building exceeds 1,000 millisieverts per hour — Levels too high for Geiger counter to measure May 13, 2011
- Officials: Radiation exposure in No. 1 building would be so high workers could not re-enter area for “several years” April 20, 2011
- Highest Yet: Radiation inside Reactor No. 1 drywell rises to 250 Sieverts per hour June 4, 2011