Fukushima Daiichi mess with breakwater visible

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  1. The continued existance of an exclusion zone and its size is the key for anti-nuclear groups. They have used the fact that there is a permanent exclusion zone around Chernobyl over and over and over again for their propaganda, frightening property owners and cities near nuclear plants to death.

    Why, in the age of GPS coordinates, high speed databases and unmanned aerial vehicles, and smartphones with could easily have features such as radiation meters built in, why do we still need to declare a “radius” around a plant uninhabitable? Shouldn’t we be able to visualize contamination to the point that we only fence off those limited spaces that actually have contamination.

    1. The evacuation “radius” is because of the uncertainty in weather patterns and which direction the winds will come from. The large circular areas are established for crisis response purposes. After the situation has stabilized an moved into the recovery and remediation phase; more precise, real measurements are used to narrow the extent of an exclusion zone. The DOE has been flying a C-12 equipped with large sensitive detectors along the coast to give a better indication of where the contamination is. The extent of the contamination certainly is as far as the evacuation radius, but the area is much smaller than a whole circle.

  2. The difference at Fukushima is the radioactive water is not inside a reactor cooling circuit. A lot of it is in an uncontrolled state flowing down the sides of buildings into storm drains, into the sea, etc.

    Also, in “sun-dried Idaho,” when water shows up at a nuclear facilities in a place where it doesn’t belong, it sets off a cascade of communications. The operator making inspection rounds notifies the shift supervisor who notifies the plant shift supervisor. Radcon is dispatched to survey the water for radioactivity. A system engineer is dispatched to evaluate the situation along with a spill response team.

    That’s a summary of plant procedures at a fully staff, undamaged facility. The situation at Fukushima is anything but normal.

    I don’t know what TEPCO is doing about capturing radioactive waste water after fresh water is being sprayed on the spent fuel pool at Unit 4 and on Units 1-3. It seems to just about everyone that doing so would be a good idea.

    The amount of fresh water being sprayed just on the spent fuel pool at Unit 4 is estimated to be in the range of 200 tons of water a day. A gallon of water weighs 8.35 pounds which yields [200 * 2000]/8.35 or about 48,000 gallons. Additional amounts of water are being sprayed on Fukushima Units 1-3. So, there is a lot of water and it is not not controlled once it leaves the spray hose from the top of the pumper boom.

    Here are some initial thoughts about where it is going after it hits the reactors.

    There is evidence from photographs that there is some loss to evaporation based on steam plumes from Units 2 & 4.

    A worst case is that the water cascades to the ground running into storm drains and on to work surfaces at ground level. Also, it may be entering pits, conduit trenches, and other underground spaces. Storm water drains probably discharge into the sea which would account for radioactivity found some distance from the shoreline.

    With all of these pathways to the surface, from the spent fuel pool about four stories up in the secondary containment building, it might be difficult to figure out how to curtail the various pathways to pooling on site or flowing out to sea.

    Logic would suggest that getting the installed cooling systems inside the reactors working again is the fastest way to stop the uncontrolled flow of radioactive water outside them and around the site. TEPCO will have to find a way to determine the condition of the pumps and piping in order to decide if this is a feasible solution.

    There is an interesting news report in the NY Times for April 8 which notes hundreds of engineers from Toshiba / Westinghouse are working on the decommissioning issue. Also, Toshiba said in a Reuters news report it thinks it can complete decommissioning of the four reactors by 2020. URL for both reports below.

    http://www.nytimes.com/2011/04/08/world/asia/08toshiba.html

    http://www.reuters.com/article/2011/04/07/toshiba-idUSL3E7F73E720110407

    1. Thank you for your insights.
      Your informative and perceptive assessment lifts the spirit and helps move beyond the paralysis of damage evaluation and scenario speculation.
      The water issue is clearly a key, but is should be fairly manageable.
      There are plenty of old tankers that could hold every drop of water in the plant with room to spare. They might then be left in dead storage for a decade in some sheltered spot, letting the radioactivity abate. It would buy time to solve the problem and also help clear the site so people can begin to tackle the actual problem.
      The airborne emissions are the other aspect of the problem. While there is some quantitative data on the water borne burden, there is nothing for the airborne load. Yet the steam plumes coming from the SFPs is surely freighted with not just iodine 131, but also long lived cesium 137.
      Is there any plausible method to address this problem? If not, it seems to pose a real threat to the entire D&D process as currently envisioned.

  3. There is going to be a continuous effort to blow everything about the Fukushima incident out of proportion and we have got to be ready as Rod has, to force things back into perspective. It may not convince the folks that are uttering this hyperbole, but it will be noted by those listening.

  4. Another aspect of the cleanup is that it will be an opportunity for a new generation to rotate through and learn the skills from a difficult cleanup. Yes, working on new designs is sexier, but with the temporary low natural gas prices the Fukushima cleanup offers a special set of opportunities as well.