Fukushima Daiichi Nuclear Plant Weekly Review

Debris dropped into a spent fuel pool at unit 3, additional cement for the floor of a manmade harbor, and the likely closure of a reactor elsewhere in Japan were among the headlines this week related to the damaged reactors at Fukushima Daiichi.

Recent developments at the Tokyo Electric Power Co. nuclear plant include:

Debris in the unit 3 spent fuel pool at Fukushima Daiichi. Source: TEPCODebris Dropped into Unit 3 SFP

A crane operator attempting to move a jumble of collapsed equipment in the spent fuel pool of unit 3 accidentally dropped a piece of debris to the bottom of the SFP. On Aug. 29, the crane was attempting to lift the console of the unit's fuel handling machine when the 880-pound component fell, coming to rest atop two fuel assemblies. TEPCO said in a release that no elevated levels of radiation were detected nearby, and crews would remotely inspect the fuel and a fuel rack for damage. (The upper part of the fuel handling equipment is pictured at left, and video of the incident is available here.)

Additional Cement Poured in Harbor

On Wednesday, the Asahi Shimbun reported that TEPCO has begun applying special cement to new areas of the seafloor in the plant's manmade harbor. The material is intended to trap mud with radioactive contamination measured at 167,000 becquerels per kilogram in some places. TEPCO coated areas adjacent to tunnels connected to the damaged reactors in 2012. Additional treatment began in July and the first of two layers is expected to be complete by the end of March.

Seismic Ruling to Close Reactor

A panel under Japan's Nuclear Regulation Authority has upheld an earlier judgment that an active fault lies under Japan Atomic Power Co.'s Tsuruga plant. Kyodo news reported Thursday that the ruling means the utility will have to scrap the unit 2 reactor at the plant.

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  • Anonymous

    If I understand this, the debris fell onto the top of the rack just as one would expect.  I take it that this was debris from 2011 and was still under water when it was dropped.

    Another website reported the incident about a week ago and made it seem like some kind of disaster.  Between the structure of the rack and the lifting attachment at the top of the fuel modules I wouldn't expect the impact to have much effect.