(3/2011) Fukushima Daiichi Power Plant- An Evolving Story

By Dr. Joseph S. Maresca

The recent 8. 9 earthquake in Honshu, Japan precipitated a considerable nuclear power crisis.  Following the earthquake, the nuclear reactors shut down.  The cooling systems failed allowing the reactor core to overheat. The tremendous heat lead to explosions which did considerable damage to the building physical site and portions of the containment systems which preclude radioactive materials from escaping into the open air. Some material has escaped into the atmosphere and the challenge is to minimize the level of the nuclear contaminants. Ponds containing used fuel rods overheated and lead to further contamination.

The fuel rods first emit hydrogen gas when exposed to the air. This gas causes an explosion in the side of the reactor building itself. Uncontrolled, the rods continue to overheat releasing more radioactive gas into the open air.  If the rods melt, dangerous quantities of radioactivity are released. The radiation releases, if uncontrolled, could approach Chernobyl levels of radiation. Helicopters in the region continue to dump water onto the involved reactors to cool down the rods at the core. Levels of radiation have increased incrementally and our State Department has advised citizens to stay at least 50 miles or more away from the site.

When a nuclear plant is next to a large volume of water (big river, lake or sea), cooling can be achieved by simply running water through the plant and discharging it at a slightly higher temperature.  There is then hardly any use in the sense of consumption or depletion on site, though some evaporation will occur as it cools downstream.  The amount of water required will be greater than with the recirculating set-up, but the water is withdrawn and returned, not consumed by evaporation.  In the UK the water withdrawal requirement for a 1600 MWe nuclear unit is about 90 cubic metres per second (7.8 GL/d).

Many nuclear power plants have once-through cooling, since their location is not at all determined by the source of the fuel, and depends first on where the power is needed and secondly on water availability for cooling.  Using seawater means that higher-grade materials must be used to prevent corrosion, but cooling is often more efficient.  In a 2008 French government study, sitting an EPR on a river instead of the coast would decrease its output by 0.9% and increase the kWh cost by 3%.

Any nuclear or coal-fired plant that is normally cooled by drawing water from a river or lake will have limits imposed on the temperature of the returned water (typically 30°C) and/or on the temperature differential between inlet and discharge.  In hot summer conditions even the inlet water from a river may approach the limit set for discharge, and this will mean that the plant is unable to run at full power. In mid 2010 TVA had to reduce power at its three Browns Ferry units in Alabama to 50% in order to keep river water temperatures below 32°C, at a cost of some $50 million to customers.  This was the same week when Rhine and Neckar River temperatures in Baden-Wuerttemberg approached the critical 28°C, and nuclear and coal-fired plants were threatened with closure.   1)  thru  13)

Sometimes a supplementary cooling tower is used to help, giving a dual system, as with TVA’s Browns Ferry and Sequoyah plants in USA, many inland plants in France and Germany, and at the Huntly plant in New Zealand, but this means that some water is then lost by evaporation.  In mid 2010,  Brown’s Ferry situation mentioned above, the six “seasonal” mechanical -draft cooling towers 18-24 m high were operating at full capacity and had been for most of the summer.  TVA will spend $160 million to add one larger (c 50 m) mechanical-draft cooling tower there by mid 2011 and then progressively replace four existing ones with improved designs shortly afterward.

Fukushima Daiichi is in crisis; however, new power lines and workers may offer a glimmer of hope. Firefighting vehicles have been dispensed to the site to replenish water spent in the fuel pool. According to reports, Unit 3 hasn’t stabilized yet. The new power lines are designed to revive electric powered pumps to supply a steady water supply to the troubled reactors and depleted fuel pools. The now famous Fukushima 50 remain onsite- perhaps doomed to death by radioactive poisoning.  The only possible remedy might be antioxidant cocktails having levels of Vitamin C and other antioxidants far in excess of normal doses.

The Fukushima Daiichi Power Plant problems were due to the earthquake. In contrast, Chernobyl was a man-made problem. Workers at Chernobyl were running a test to establish coping mechanisms in order to handle the shutdown of the cooling system. The test failed precipitating a gross and uncontrolled power surge which blew the roof off the reactor vessel and building. This explosion resulted in the reactor core being exposed which resulted in radioactive material leaking into the atmosphere uncontrolled.  With today’s technology, Artificial Intelligence and Advice Giving Systems may be utilized to draw upon a community of experts in order to minimize cooling system problems and uncontrolled power surges.

A search of USPTO Patents will produce additional methods to deal with coolant system problems and uncontrolled power surges at nuclear power plants.

Another important difference from Chernobyl involves the automatic shutdown of the Fukushima Daiichi Plant when the earthquake commences. This shutdown mechanism will be triggered by sophisticated motion sensors which track earth movements and halt plant operations in a relatively short period of time.  Once the coolant begins to overheat, the plant shuts down without human intervention.  14)

The problems at the Fukushima Daiichi Plant imply the need for the following types of enhancements:

o Redundant water, cooler systems and uninterruptible power sources

o The use of artificial intelligence and advice giving systems to articulate cooling system problems and uncontrolled power surge events. 

o Locating new plants away from earthquake fault lines.

o The use of Unmanned Monitoring Devices to establish baseline profiles for tremor activity.

o A comprehensive , tested and updated Contingency Plan and Disaster Recovery Plan for nuclear power plant operational continuity and de-activation in an emergency

o The “Artificial Sun” Fusion Power Plant may be the longer term solution.

o Robots and unmanned probing devices may reduce the level of human intervention needed at contaminated sites in the not-too-distant future.

An earthquake measuring 6.1 on the Richter scale jolted near the east coast of Honshu, Japan 1:13 p.m. local time (0413 GMT) on Thursday, 3-17- 2011, the U.S. Geological Survey said.  The epicenter, with a depth of  25.3 km, was initially determined to be at 40.19 degrees north latitude and 142.20 degrees east longitude.  The quake is 271 km east of Fukushima, where the Fukushima nuclear power plant was damaged by a 9.0-magnitude earthquake last Friday.    15)

The nuclear energy industry and chemical process industry are the leading users of zirconium and hafnium.  Zirconium is explosive at 2000F and emits hydrogen gas.  Chromite and olivine can be used instead of Zircon for some foundry applications. Dolamite and spinel refractories can substitute for Zircon in certain high temperature applications. Columbium (niobium) , tantalum and stainless steel provide limited substitution for zirconium alloys in nuclear applications.  Titanium alloys and synthetic materials may substitute for Zirconium alloys in some chemical plant uses. Zirconium can be used interchangeably with hafnium in certain superalloys.    16)

On June 26, 1954, at Obninsk, Russia, the nuclear power plant APS-1 with a net electrical output of 5 MW was connected to the power grid.  The world’s first nuclear power plant generated electricity for commercial use. On August 27, 1956 the first commercial nuclear power plant, Calder Hall 1, England, with a net electrical output of 50 MW was connected to the national grid.

As of Jan 19, 2011 in 30 countries, 442 nuclear power plant units with an installed electric net capacity of about 375 GW are in operation and 65 plants with an installed capacity of 63 GW are in 16 countries under construction.

As of end 2009 the total electricity production since 1951 amounts to 64,600 billion kWh. The cumulative operating experience amounted to 14,174 years by September 2010.    17)

References:

1)  UK Environment Agency, 2010, Cooling Water Options for the New Generation of Nuclear Power Stations in the UK.

2) EPRI 2002, Water and Sustainability (volume 3): US Water Consumption for Power production – the next half century, EPRI Technical Report

3) DOE/NETL 2006: Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements, DOE/NETL-2006/1235

4) DOE/NETL 2008: Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements, update, DOE/NETL-400/2008/1339

5) DOE/NETL 2009: Water Requirements for Existing and Emerging Thermoelectric Plant Technologies, DOE/NETL-402/080108

6) EPRI 2008, Water Use in Electric Power Generation, EPRI Report 1014026.

7) EPRI 2011, National Cost Estimate for Retrofit of U.S. Power Plants with Closed Cycle Cooling, EPRI Technical Brief 1022212;

and Closed Cycle Retrofit Study: Capital and Performance Cost Estimates, EPRI Technical Report 1022491.

8) DOE/NETL August 2010, Water Vulnerabilities for Existing Coal-Fired Power Plants, report 1429.

9) DOE/INL 2010, Cooling Water Issues and Opportunities at US Nuclear Power Plants, Oct 2010, INL/EXT-10-2028.

10) OECD Projected Costs of Generating Electricity 2010,

11) Nuclear Engineering Handbook 2010

12) ESAA, Electricity Gas Australia 2010

13) http://www.world-nuclear.org/info/cooling_power_plants_inf121.html

14) Why Fukushima Daiichi Won’t Be Another Chernobyl,

     Michael Marshall, New Scientist Physics and Math

15) http://news.xinhuanet.com/english2010/world/2011-03/17/c_13783698.htm

16) http://minerals.usgs.gov/minerals/pubs/commodity/zirconium/zircomcs07.pdf

17) http://www.euronuclear.org/info/encyclopedia/n/nuclear-power-plant-world-wide.htm

Joseph S. Maresca Ph.D., CPA, CISA, MBA: His significant writings include over 10 copyrights in the name of the author (Joseph S. Maresca) and a patent in the earthquake sciences. He holds membership in the prestigious Delta Mu Delta National Honor Society and Sigma Beta Delta International Honor Society.  In addition, he blogs and reviews many books for Basil & Spice. Visit the Joseph S. Maresca Writer’s Page.

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