The MIT  nuclear reactor tour was a great way to see first hand how nuclear energy was produced and what the process was. Although I was a bit confused, the tour throughout  helped to clear this up a bit as our leader led us through the different parts of the reactor. Seeing the machines up close and hearing how they operated was a surreal experience, and a little bit scary.  However, it made me feel better that the lab is used only for  research and not to generate power. Still, walking into the reactor was intimidating and I felt worried. Perhaps this was because  the facility was locked down with a lot of security, and had to have prior personal information about us if we were to enter the facility. When we were checked in we were given a device that monitored radiation called an embitter. We were instructed to carry this on us at all times and to leave our cellphones and other personal belongings in a room outside of the reactor. This was a bit alarming to me, and made me realize how seriously the production of nuclear energy needed to be taken. It made the experience very real for me.

I thought it was really interesting how they were able to add things directly to the reactor to see the reaction as it seems very beneficial to the facility’s research. Furthermore, the fact that they used to use the reactor to treat cancer patients was very intriguing and good to hear. I was eager to learn more about the process and disappointed to hear that although it was very effective, they had stopped treating patients due to cost. When we went downstairs in the reactor, we got to see where the patients were treated, which was a bit spooky, but also very cool! This was probably the most interesting part of the tour for me because it was a real life application of the things we were learning about nuclear energy in class!

Following the Great East Japan Earthquake of magnitude 9.0 at 2.46 pm on March 11, there was considerable damage in the region which was only increased by the large tsunami that was created as a result. “The earthquake was centred 130 km offshore the city of Sendai in Miyagi prefecture on the eastern cost of Honshu Island (the main part of Japan), and was a rare and complex double quake giving a severe duration of about 3 minutes.”. Furthermore, the tsunami destroyed 560 sq km and resulted took the lives of over 19,000 people. There was also a lot of damage to coastal ports and towns, including the destruction and collapsing of over a million buildings.T he Fukushima accident was rated 7 on the INES scale, due to high radioactive releases over days 4 to 6 days.

The area was evacuated by more than 100,000 people  for fear of radiation sickness from the nuclear disaster. Moreover, other major issues concerning this event include the highly radioactive water in the basements of reactors 1-3, signifying damage to the reactor pressure vessel. The leakage was not able to be explained but was must likely a result of the reactor core. Also, the evaporated sea water  can clog the cooling pipes and weaken the cooling effect, which is concerning.

What happened in the reactors was this:

It began flooding and almost all power was lost along with workers getting killed instantly while the water began entering the station. Then, the cooling system failed  and in the now damaged control room, workers found out that the pressure levels were increasing and that they needed to bring the pressure down to prevent disaster.  These reactors  have pressure release valves that are used to release pressure, the valves were ordered to be opened  in order to release pressure into the air. Inside of the plant, however, scientists argued against this plan because if steam were to be released into the air, this steam would carry radioactive material. But, they were under orders and set off to find the valve with only lanterns to guide them. Then, reactor number one exploded from the post quake which dramatically increased radiation levels and  two days later, an even larger explosion effects reactor 3, causing radiation levels to rise even higher and when reactor 4 exploded the next day, everything began melting. Then, the three safety measures taken to cool everything failed.

This is in inside of a reactor:

“when the power failed at 3.42 pm, about one hour after shutdown of the fission reactions, the reactor cores would still be producing about 1.5% of their nominal thermal power, from fission product decay – about 22 MW in unit 1 and 33 MW in units 2 & 3. Without heat removal by circulation to an outside heat exchanger, this produced a lot of steam in the reactor pressure vessels housing the cores, and this was released into the dry primary containment (PCV) through safety valves. Later this was accompanied by hydrogen, produced by the interaction of the fuel’s very hot zirconium cladding with steam after the water level dropped.

As pressure started to rise here, the steam was directed into the suppression chamber under the reactor, within the containment, but the internal temperature and pressure nevertheless rose quite rapidly. Water injection commenced, using the various systems provide for this and finally the Emergency Core Cooling System (ECCS). These systems progressively failed over three days, so from early Saturday water injection to the reactor pressure vessel (RPV) was with fire pumps, but this required the internal pressures to be relieved initially by venting into the suppression chamber/ wetwell.”

http://www.world-nuclear.org/info/safety-and-security/safety-of-plants/fukushima-accident/

As a result of this disaster, Japan has been developing new energy strategies. These strategies include the following:

• reducing in the oil-dependency rate to 40% or less by 2030 from the current 50%,
• promotion of nuclear energy, and securing of energy resources abroad through the fostering of more powerful energy companies
  
• promotion of nuclear energy
• new plants to replace old ones
• the  increasing the ratio of “Hinomaru oil”, or oil developed and imported through domestic producers, from the current 15% to 40% by 2030. To achieve that goal, the new strategy emphasizes the need to foster Japanese oil majors that can compete with foreign rivals.
• the restart of reactors

http://www.atimes.com/atimes/Japan/HA13Dh01.html

Cabinet’s new energy plan praised by pro-nuclear U.S.

Our world has become quite polluted over time as a result of our waste materials from generating heat and electricity. Inevitably, we are headed toward global warming. Luckily, there are many advances in alternative energy sources and in this post I will be talking about geothermal energy in particular. Geothermal energy is the process of taking heat from the earth and converting it into energy that can be used as a source of electricity and heat. Recent technological advancements have allowed the utility scale to produce 12 million US households worth of energy that is cheaper and cleaner than other ways of producing electricity.  Geothermal energy is created when Earthquakes create magma movement and break up rocks below the Earth’s surface, which his allows hot water to circulate and rise to the Earth’s surface so the heat from the water is used to produce electricity (as seen in the image below).

The following image from truegreengeo.com shows how geothermal energy is acquired.

Currently, Iceland is the “pioneer” in the use of geothermal energy throughout the world as it has 5 geothermal power plants; Iceland generates 25% of its energy and roughly 85% of the country’s heat from geothermal systems ! This high level of productivity from the geothermal sources is mostly created through steam, which is naturally occurring due to the high amount of volcanic activity and hot springs in Iceland, which are around 150 degrees Celsius. Because the ground is unstable due to the volcanic activity, however, the plates are frequently moving and thus causing earthquakes. According to the National Energy authority, “During the course of the 20th century, Iceland went from what was one of Europe’s poorest countries, dependent upon peat and imported coal for its energy, to a country with a high standard of living where practically all stationary energy is derived from renewable resources. In 2011, roughly 84% of primary energy use in Iceland came from indigenous renewable resources. Thereof 66% was from geothermal.”

Clearly, there is a lot to look into with Iceland’s success with geothermal energy!

http://www.nea.is/geothermal/