Is Fort Calhoun's dry cask storage for high-level radioactive waste being protected against flood waters?

A photo showing the dry cask storage facility at the flooded Fort Calhoun nuclear power plant (see red circle in picture above) on the Missouri River seems to reveal that it is located outside of the vital area defended by the one-third mile long, 8 foot tall, Aqua Dam, a water filled rubber wall. This raises the concern that flood waters could block the foot vent that allows the cooling air flow convection currents to remove heat from the dry casks, leading to overheating.

Restoration of cooling water circulation in Unit 4 high-level radioactive waste storage pool more challenging than Unit 2 at Fukushima Daiichi

A photo, taken through the camera's protective cover, shows workers in the turbine building of unit 2 (Image: Tepco)World Nuclear News reports that, despite very high humidity levels of 99.9% (like a radioactive sauna -- see photo at left), the May 31st re-establishment of cooling water circulation at Fukushima Daiichi's Unit 2 reactor building had succeeded by June 10th in reducing the temperature in the high-level radioactive waste storage pool 31 degrees Celsius (88 degrees Fahrenheit), near Tokyo Electric Power Company's goal of 25 degrees Celsius (77 degrees Fahrenheit). However, due to extensive damage at the Unit 4 high-level radioactive waste storage pool, it appears that such a fix won't be so easy. Unit 4's pool water is now 80 degrees Celsius (176 degrees Fahrenheit), dangerously close to boil. If the Unit 4 pool water boils away, exposing irradiated nuclear fuel to air, it could overheat, ignite, and release catastrophic amounts of hazardous radioactivity onto the winds and waves. 

Fukushima Daiichi Unit 4 High-Level Radioactive Waste Storage Pool in critical condition

Photo taken by Tepco on June 10thNHK World public broadcasting in Japan has reported that a small work crew entered the Fukushima Daiichi Unit 4 secondary containment reactor building to inspect, and attempt to repair, the still dangerously overheating high-level radioactive waste storage pool. But, as reported at Daily Kos's Japan Nuclear Incident Live Blogs by FishOutOfWater, the work crew found severe damage and obstacles of fallen debris, including a water pipe crucial to restoring cooling circulation (see bent pipe in top center of photo at left). This will require a new approach to restoring cooling, that will take yet more time to figure out how to do, as the pool water hovers at 80 degrees Celsius -- close to the boiling point. If the water boils away, exposing the high-level radioactive waste to air, it could again catch fire, spewing deadly radioactive gases and particles directly onto the wind. Also, as reported by the Daily Kos blog, the Unit 4 pool is being shored up by steel support pillars, as it, and the building that houses it, leans precariously following a large-scale hydrogen explosion of still-indeterminate origin in the first days of the nuclear catastrophe in mid-March. The collapse of the pool could result in instant catastrophic loss of cooling, and large-scale radioactivity releases. Evidence also points to an ongoing nuclear chain reaction, due to the presence of high-levels of short-lived radioactive iodine-131 in the pool water. But the origin of the explosive hydrogen gas, and the location of the nuclear chain reaction -- whether from within the Unit 4 pool, or not -- remain a mystery.

Video by robot camera of massive damage within Fukushima Daiichi Unit 3 high-level radioactive waste storage pool

Still image from Tepco robotic camera showing Unit 3 storage pool for high-level radioactive waste largely clogged with debrisThe London Telegraph has posted video released by Tokyo Electric Power Company from early May, showing the reactor Unit 3 high-level radioactive waste storage pool at Fukushima Daiichi largely crammed full of debris caused by the massive hydgrogen explosion which left the secondary containment building a pile of rubble. Incredibly, Tepco and Japanese federal government officials have claimed the high-level radioactive waste in the pool remains largely intact, despite the explosion and resulting aftermath visible in the pool. A YouTube video shows the explosion of March 14th at Unit 3 -- the second of four such explosions at Fukushima Daiichi. Unit 1 exploded first on March 12th, followed by Unit 3 on march 14th. Unit 2's explosion occurred within the primary containment structure, severely damaging it, creating pathways for release of large-scale, catastrophic radioactivity releases into the environment. Unit 4's explosion was at first believed to have been caused by a boiling dry of the high-level radioactive waste storage pool, followed by a fire within the waste itself; however, the U.S. Dept. of Energy now theorizes that hydrogen gas from Unit 3 may have travelled through a common venting system, rather than out their common smokestack, into Unit 4's secondary containment reactor building , blowing it up.

Sludge resulting from decontaminating cooling water at Fukushima Daiichi will be intensely radioactive

The Mainichi Daily News has reported that the sludges generated by the decontamination of the 100,000 tons of cooling water used to prevent further melt-throughs at the Fukushima Daiichi nuclear power plant in Japan will contain 100 million becquerels of radioactivity per cubic centimeter. The radioactively contaminated cooling water itself is reported to emit a radiation dose rate of 100 rem per hour. Since a 1,000 rem dose is considered enough to kill everyone exposed to it, 10 hours of exposure to this radioactively contaminated cooling water at Fukushima Daiichi -- at close proximity, and without radiation shieldling -- would easily deliver a lethal dose. Thus, significant precautions must be taken with its handling and processing. But Tokyo Electric Power Company has run out of storage space for the water. Fears are compounded that the approach of raining season could overwhelm the plant grounds, causing an overflow into the ocean. No interim storage nor final disposal pathways have been determined for the sludge. Water decontamination efforts will begin -- with help from the U.S. and French nuclear industries -- on June 15th at the earliest, as the decontamination process must be invented "from scratch."