Recent content by NUCENG

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    Draft SFP Earthquake Risk Study Available for Comment

    Here is your opportunity to weigh in on one of the Fukushima issues. First link is the study and second link discusses the comment process. http://pbadupws.nrc.gov/docs/ML1313/ML13133A132.pdf http://pbadupws.nrc.gov/docs/ML1317/ML13175A104.pdf
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    San Onofre steam generator tubes leaking - why?

    And Fort Calhoun hasn't got a restart from the CAL (confirmatory Action Letter) yet as far as I know.
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    San Onofre steam generator tubes leaking - why?

    SONGS Closing Pulling the plug: http://www.cbsnews.com/8301-201_162-57588196/calif-utility-to-retire-troubled-san-onofre-nuclear-power-plant/
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    Energy calculation for HVAC systems

    ASHRAE provides standard heating and cooling procedures for estimating heating and cooling energy balances. See if you can access any of their handbooks or technical standards at your school or company library. www.ASHRAE.orgor get an estimate from a heating and air conditioning contractor or...
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    How is hydrogen generated and managed in Hanford's double-shell tanks?

    Based on the discussion in the report it appears they use active ventilation on some of the tanks, not inerting. The basic problem is that tanks can leak and are leaking and need to be cleaned up. That would also eliminate issue with hydrogen.
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    And their alternatives are what? Are there any indications that corium can still be in a molten state after 2 years? Has any radiological evidence of reactivity changes indicated an impending recriticality? They are injecting water through both feedwater and spray piping. Adjustments in these...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    I agree, the temperature began to increase. earlier. but the dates of adjustments in flow are consistent with beginning to cool it back down and then reducing flow after the cooldown returned to the previous value. The beginning or the heatup on the 8th or 9th could be the start of the flow...
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    How is hydrogen generated and managed in Hanford's double-shell tanks?

    Here is a link to an analysis from 2008 indicating 2 weeks to a month to reach a specific level below the LFL (Lower Flammability Level) after loss of ventilation for tanks with active ventilation or Passive HEPA filtration. The reference you provided and similar liinks from a Google search...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    Tsutsuji, I've been missing something important until you reposted that link. The drawing shows a pipe penetration directly from the torus room to the turbinge building basement. Further it shows a sleeve around the pipe which is not water tight, much less air tight. In US BWR3 and BWR4 plants...
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    Is there a way to generate heat through friction without damaging the generator?

    Paddlewheelers weren't much good during winter due to ice. Running a paddlewheel adds a mechanical device capable of wear, blockage, and failure. An electric generator and heater powered from a windmill is more costly and also adds another energy conversion and inefficiency, but might be more...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    Possible explanation or contributing factor: http://www.tepco.co.jp/en/press/corp-com/release/2013/1224790_5130.html From TEPCO Daily status report: "-At 12:35 PM on February 15, Unit 2 reactor injection water amount was adjusted as follows since the amount had fluctuated. Feed water system...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    Co-60 It is clear that the fission product yield of Co-60 is near zero and that wouldn't be significantly different in a criticality accident even assuming fast fission. Old Soviet Submarine fuel designs may have used stainless steel cladding which would explain increased Co-60. So it looks...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    Sorry, I didn't understand that. Jim is right that activation of Cobalt is the masin source of Co-60, and that requires a neutron flux consistent with your last post, but if I was reading Japanese correctly the sample was near Unit 4. Your initial post suggested there was a lot of Co-60 from the...
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    Japan Earthquake: Nuclear Plants at Fukushima Daiichi

    I may be mistranslating, so please help me out. But this appears to be data about debris and tree clearance samples. The reports for Co-60 Bq/gm activity are four orders of magnitude lower than Cs-137. Agreed, Co-60 is a very energetic radiation source, but its activity is hardly a "large...
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    Fallout yield from a nuclear accident at sea?

    Thank you. More interesting reading. There is a certain amount of sick fascination with how that could happen repeatedly. One thing that could really be causal is the desperate competition between the Soviets and the West during the Cold War. Today, we seem to be moving back in that direction...
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