The solar panel experiment that we did in class on March 20 was a good learning experience.  The experiment tested the energy absorption of different light frequencies that varied in color.  We also tested the differing intensity of light at various distances.  This part of the experiment was done first to test the energy absorption of the solar panels that we used.  The first trial was without any light and it yielded the lowest energy levels.  After that we did trials with the light source a varying distances.  We tested the solar panels with the light source up against the light, then at a distance of 10 cm, 20 cm and 30 cm.  As the light source got farther away from the panels the average energy went down.  This is likely because the farther that the light source was from the solar panel the more that the photons spread out and so the less intense the focus of photovoltaic energy was on the solar panel.  This part of the experiment was rather straightforward.  The table below displays the data from those trials.

For the second part of the experiment we tested three different light frequencies.  We used red, green, and pink light for each trial respectively.  This experiment tested which frequency of light was best for converting photons into energy.  Each trial was done at a distance of 0cm between the light source and the solar panel.  The results showed that Red, the color with the lowest frequency of all visible light, had the lowest energy output.  The average energy output from the red light over 10 seconds was .35.  The next highest frequency of the colors we tested was Green, which measured an average of .44.  Lastly, the pink light generated the most energy because it has the shortest wavelength and highest frequency of the colors we tested.  Pink measured at .49.

This experiment was important to do because it demonstrated the different effect of light frequency on solar energy.  The higher the frequency the more energy that can be gained from the light.  Red had the largest wavelength and lowest frequency of the light we tested which is why it yielded the least energy.

On March 11, 2011 a major earthquake created a tsunami measuring over 50 feet that hit the coast of Japan most severely in Fukushima Daiichi.  Upon impact the tsunami disabled the power supply and cooling systems of three nuclear reactors, causing all three cores to melt within three days and high radioactive releases.  The most imparative ongoing struggle regarding the incident was to prevent the release of radioactive materials from contaminated water that leaked from the three reactors.  Over 100,000 people had to be evacuated from their homes, though there have been no reported deaths or cases of radiation sickness. According to an expert report commisioned by the World Health Organization the nuclear disaster has increased the risk of cancer in the radiation affected areas.

The earthquake that caused the disaster was measured as a 9.0 on a 10 point scale.  The resulting tsunami caused even more damage than the original quake, which happened about 100 miles off the coast of the city of Sendai.  Furthermore, the quake was a actually a rare and complex occurance known as a double quake giving a severe duration of about 3 minutes.  Japan moved a few meters East.

The Daiishi reactors proved structurally stable after the quake but were flooded when the resulting tsunami hit the coast.  Generators were used to power the Residual Heat Removal (RHR) system, which serve to cool the cores.  In some reactors the generators on site were flooded as well.  Without heat removal by circulation through an exhaust system, pressure gathered from steam in the cores.  Water was used to try and cool the plant along with the Emergency Core Cooling System.  However, these systems failed and the fuel in the core rose to 2800 degrees Celcius or about 5100 degrees Fahrenheit, which caused the core to melt.  Also, as pressure rose there was an attempt to vent the gas, but without power the gases backflowed to the service floor at the top of the reactor. Here noble gas, aerosols and hydrogen mixed with air and ignited causing a hydrogen explosion on the service floor of the Unit 1 reactor.  Eventually the melted core of Unit 1 eroded through 65 cm of the drywell concrete below the reactor, which is a total of about 260 cm thick.  In the concrete the intensity of the heat was reduced and the mass solidified.

References:

http://www.world-nuclear.org/info/Safety-and-Security/Safety-of-Plants/Fukushima-Accident-2011/

http://www.foodconsumer.org/newsite/Non-food/Environment/fukushima_daiichi_nuclear_disaster_0228131027.html

http://www.abc.net.au/news/2013-03-07/water-from-the-tsunami-that-hit-the-fukushima/4558338