The last week brought news of radioactive water leaks at Fukushima Daiichi and its manmade bay, as well as the first MOX shipment to Japan since the 2011 earthquake.

Developments related to the station blackout at Fukushima caused by that earthquake and tsunami include:

Fukushima Daiichi's harbor pictured 6/26. Source: TEPCOElevated Tritium Found in Harbor

After observing elevated contaminant levels in sample wells outside turbine buildings, Tokyo Electric Power Co. said in a release that testing June 21 detected tritium at concentrations as high as 1,100 becquerels per liter in the plant's artificial harbor. The Asahi Shimbun quoted the utility as saying levels in some areas had increased to 1,500 becquerels per liter by Wednesday, although levels in other parts of the harbor dropped. TEPCO blamed the rise on contaminated water that had accumulated inside a barrier wall currently under construction.

Another Leak at Desalination Plant

About 250 liters of highly contaminated water leaked from a desalination system that is part of the makeshift circuit cooling the damaged reactors. The water was confined to a warehouse, according to a TEPCO release, and was discovered in the early morning of June 21. TEPCO concluded the leak was caused by a flow meter cap overtightened during maintenance the previous day. The flow meter was replaced and the desalination system restarted.

MOX Shipment Arrives at Takahama

Areva delivered 20 MOX fuel assemblies to Kansai Electric Power Co.'s Takahama 3 reactor Thursday. The recycled fuel, which faces opposition among the Japanese public because of its plutonium content, had not been delivered to Japan since shipments were suspended immediately after the earthquake. Another 20 MOX assemblies will be shipped to the reactor, the Yomiuri Shimbun reported, which will seek permission to restart when the Nuclear Regulation Authority finalizes its new regulations next month.