Monthly Archives: April 2011

News updates, April 15

News Updates, 4/15/11 An earthquake (magnitude 5.4) was reported at Hamadori, Fukushima Prefecture on 4/13. No unusual events were reported at any of the nearby nuclear power stations as a result of this. Injection of fresh water into Units 1-3 … Continue reading

Posted in Fukushima

New Provisional INES Rating + A Chernobyl Primer

Today the Japanese Nuclear and Industrial Safety Agency revised its INES rating of the Fukushima Daiichi event. The previous assessment treated the events at each of the ailing reactors as separate: the core damage to units 1-3 resulted in an … Continue reading

Posted in Incident History

News updates, April 11

News Brief, 4/11/11 Aftershocks The region surrounding the troubled nuclear power station has suffered two aftershocks in recent days. The first, a magnitude 7.1 on the Richter scale, took place on 4/7/11. This aftershock injured thousands, and killed four, but … Continue reading

Posted in Fukushima

Regulatory Limits on Radiation Dose

Safety Limits: What are they? How are they determined? Much of the discussion concerning radiation levels and radioactive material releases has been presented in the context of safety limits set by a regulator. Examples of such limits include the I-131 … Continue reading

Posted in Radiation Protection

News updates, April 6, 2011

News Brief, 4/6/11 TEPCO has reported that as of 5:38 AM JST, the leakage of water from Unit 2’s supply cable pit has stopped. Before and after photos supplied by the IAEA are shown below: After it was found that … Continue reading

Posted in Fukushima

News brief, April 4

News Updates, 4/4/11 TEPCO has identified a potential pathway by which water from Unit 2 may have been leaking into the Pacific Ocean. This pathway consists of a 20 cm crack in the concrete wall of a pit which holds … Continue reading

Posted in Fukushima

News updates, April 1

News Brief, 4/1/11 Status of Reactors Efforts are still underway to pump water from the turbine buildings of the reactors. Water in the turbine buildings is being pumped directly into the reactors’ condensers. The IAEA reported yesterday that the condenser … Continue reading

Posted in Fukushima