Archive for March, 2011

Despite the unfolding tragedy in Japan.  GE Hitachi in Castle Hayne is reporting that all 44 workers are safe.  They are arranging for their safe return.  When a reactor needs service the utility brings in off site technicians to expedite the labor intensive work.  Jobs such as refueling and repairs require many more people than the utility has on staff.  This is because

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As we have discussed here before, The GE Mark 1 BWR (Boiling Water Reactor) has its root in the 1950,s.  Back then the engineers could not have imagined supporting this design in the year 2011.  It is sort of like trying to get a 1955 Chevy to meet all of todays safety and crash standards.  In fact GE has done a remarkable job.  It is also a testament to the sheer robustness of the design.

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Japanese officials have confirmed that the core which houses the reactor at Fukushima 3 is intact.   As if nuclear experts in Japan did not have enough problems to deal with;  now blast damage is mounting.

Japanese officials have just confirmed that an explosion has just occurred at the Fukushima number 3 reactor.

The answer to that question is being sought by the American people.  The troubled Fukushima reactors are GE Mark 1 BWR designs.  These reactor cores stay hot for days if not weeks following an emergency.  Their massive plumbing networks are their Achilles heel during a massive earthquake.  The reactors work by creating heat and superheating the surrounding water.  That water is then turned into steam and turns a massive turbine under high pressure.  It is then cooled and returned.  All of the plumbing is meant to contain these massive pressures and heat.  The huge external stresses caused by the earthquake and tsunami have severely damaged the system.  In a later post we will discuss the newer more inherently safer technologies.  Designs like the Traveling Wave Reactor, Pebble Bed Reactor, and a handful of new mini reactor designs.  For now all we can do is pray for Japan.

Seawater, with its high salt content is notoriously corrosive.  This Highlights the extent of the emergency at Fukushima 1, and 3.  This seriously calls in to question ever using these reactors again for power generation.  The combination of massive heat, corrosive saltwater, and high pressure in these highly radioactive enviroments will be an extreme challenge to the Japanese nuclear experts.  Repair and cleanup will take years.

The Japanese nuclear safety agency has declared the Onagawa nuclear site safe after reports of raised radiation levels.  Japanese experts state that the raised levels of radiation were caused by the radioactive steam released at the troubled neighboring Fukushima site.

The Fukushima nuclear site in Japan has 6 active BWR (Boiling Water Reactors).  The roots of this design date back to the 1950,s.  Tokyo Electric Power Co. has reported that all 6 have been experiencing cooling problems.  As the cooling problems mount authorities have to deal with damaged basic infrastructure, evacuations, radiation releases, and now blast damage.  New cooling operations are using sea water and boric acid to stave off a meltdown.  These are massive piping facilities.  A true evaluation and assessment of the total damage under the best circumstances would take months under good circumstances.   Tokyo Electric Power Co. actions have become steadily more desperate.

As the world continues to monitor the crisis in Japan;  NCNUKE is busy at work to provide our readers with the most topical information.  The Fukushima Daiichi 1 reactor is a GE Mark 1 BWR (Boiling Water Reactor).  It is the same reactor design used by the Brunswick Station in Southport NC.  Here is a list of all the GE Mark 1 reactors in the USA.

Browns Ferry Units 1,2, and 3

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We continue to monitor the explosion of the containment building in Japan.  The containment building is a steel reinforced concrete structure.  It is airtight and contains the reactor, its pressurizer, coolant pumps, steam generator, and basically all the equipment and piping.  It appears as if the entire structure has been compromised.   This crisis has become dramatically worse.  Experts are now doing all they can to avoid a meltdown.  Stay tuned to this site for frequent updates.