Tuesday, September 18, 2007

Fungus Reveals New Forms of Energy Production

A surprising discovery published back in May reveals that some fungi can create energy with the help of melanin, a pigment also found in human skin. The fungi was first discovered within the contaminated chambers of the Chernobyl reactor, where the flourishing black masses were first observed by scientists Ekaterina Dadachova and her colleagues at the Albert Einstein College of Medicine, in New York City.
In laboratory conditions, it was found that the fungi Cryptococcus neoformans, when exposed to radiation, uses this energy as a plants would use light, to produce growth. Scientists have long known certain fungi can digest plastics, oils and asbestos. Now they are hopeful that this breakthrough could provide insight as to how to deal with nuclear waste and produce food in conditions with high radiation levels. But this discovery is also important in that so far it was thought that only plants could make food through photosynthesis.
And what does this mean for the melanin in our bodies- is it possible that this plays some unknown role in humans?
Dadachova pointed out to Technology Review that "The mechanism of this process needs to be established. It took at least two decades and the work of several research groups to determine the mechanism of photosynthesis."

For the abstract in PubMed.com
Check out the interview with Dadachova in Technology Review

Monday, September 17, 2007

Nuclear Energy Revisited

Friday I attended a lecture on Nuclear Energy as a green power source, hosted by the Long Now Foundation. Nuclear energy is green? So say the experts, Dr Gwyneth Cravens and Dr. Richard Anderson.
Coal is the largest source of energy in our country, accounting for 51% of the total production. Nuclear is at 20%, hydor is 7%, and alternatives make up the rest of the whole. Hydro is currently maxed out, and coal accounts for an estimated 24,000 deaths in the United States per year, in addition to the damage atmospherically.
According to the experts, when comparing the environmental advantages of nuclear energy over coal, there is no doubt that nuclear energy is a safe and viable alternative. Uranium is plentiful and readily available. The size of the power plants is extremely small compared to the vastness of coal plants. Nuclear can provide the base load required of power plants, the available power so when demands spike, there is enough power to meet immediate demands. Unfortunately, wind and solar cannot provide the base loads. And nuclear energy creates virtually no atmospheric pollution, in fact, it creates hardly any waste at all. The amount of spent energy left over if a person received their power from nuclear their entire life could fill one coke can. With coal, a person would fill nine train cars full of waste in their lifetime. Now multiply that by the number of people out there. Where will we put all that waste?
One of the big concerns about nukes is their potential to expose people to radiation. The lecturer said she had her fears, and researched this possibility quite extensively. The Three Mile Island accident resulted in successful containment and cleanup, and injured no one. The nuclear plants she visited emit approximately .09 millarems per year (millarems is a factor that calculated human safety). She pointed out an interesting fact- there are .1 millarems in a banana. In some urban areas in the United States, the Bay Area for example, people are exposed to thousand times more millarems per year, from naturally occurring radiation.
Cigarettes expose humans to astounding amounts of radiation, and the lecturer claimed that most nuclear scientists would recommend quitting smoking as the number one way to reduce your radiation exposure.
Chernobyl seems to be the best example of a bad accident involving nuclear power. Indeed, Chernobyl is not a good example of potential accidents, as it was built without any containment fields, without the proper subterranean design found elsewhere, built from inferior materials, and without the proper safety features. It was the worst of the worst, and when the reactor began to malfunction, workers who were not properly trained interrupted the only safety measure that would have prevented the meltdown- they turned off the water.
The threat of terrorism is negligible, according to the experts. They pointed out the incredible safety meausres at plants, the building construction that would stop any air attack, and the fact that stealing the enriched fuel for making bombs would be impossible to accomplish, as the sheer weight of the material and the immediate personal danger alone are too gargantuan.
Its not life someone can slip a piece of enriched uranium in their pocket and sneak off with it.
The last point of the lecture was the disposal of nuclear waste. First off, nuclear engery is now 98% efficient when spent fuels are reprocessed. This means that previously disposed materials could be reclaimed and reused. That technology is always improving. A new storage facility in New Mexico, located in a salt deposit thousands of feet below the earth's surface has been created by the military, and the only thing stopping us from safely storing material here is politics.
It seems the biggest obstacle to creating more power plants and reducing the effects of coal and global warming are public opinion and the fact that we are producing no young nuclear physicists. We simply cannot ramp up quickly enough to slow global warming.
While I must admit I was surprised, and still hold some skepticism about the safety of storing spent nuclear waste, I found myself imagining a world where the power was nuclear. It seems like something we greenies should definitely start looking into, instead of immediately rejecting the idea, as I did once.
For a link to the Long Now Lecture Series
For the Wiki on Three Mile Island