paula l. diaconescu

NUCLEAR POWER AS

ALTERNATIVE ENERGY

Paula L. Diaconescu

Why talk about nuclear energy?

N

N

N

N

NN

Fe

N

Me2tBuSi

N

Me2tBuSi

U

http://copper.chem.ucla.edu/pldgroup/index.htm

http://copper.chem.ucla.edu/pldgroup/index.htm

Whitesides Science 2007

The news Nuclear power now generates 15% of

the world's electricity.

The International Atomic Energy Agency expects at least 70 new plants to be opened within the next 15 years. This could result in a doubling of the amount of electricity produced by nuclear plants.

The small- and medium-sized reactors now in development could help meet energy needs in the more remote areas of the world. They don't run on fossil fuels so their location isn't constrained by access to oil, gas or coal. Nor do they require the expensive infrastructure of national electricity grids.

Time to Embrace the Nuclear Option – The Wall Street Journal, February 3, 2010

Locations of nuclear power plants

Why not more? a combination of alternative and plentiful energy sources, high costs,

the impact of the Chernobyl disaster as well as scare campaigns

MWC News, February 5, 2010

The problem: nuclear waste

Perhaps the single biggest expense of the nuclear power is the storage of nuclear waste.

Currently: temporary storage

Viable long-term solution has yet to be found (storage needed on the order of thousands of years).

Nuclear power is the only energy industry which takes full responsibility for all its wastes, and costs this into the product.

http://www.world-nuclear.org/education/wast.htm


Radioactivity arises naturally from the decay of particular forms of some elements, called isotopes.

Types of radioactivity alpha beta gamma neutron radiation:

only inside a nuclear reactor

All of these kinds of radiation are, at low levels, naturally part of our environment. Any or all of them may be present in any classification of waste.

Radioactivity



Types of radioactive waste

Low level: hospitals, laboratories and industry, as well as the nuclear fuel cycle paper, rags, tools, clothing, filters, which contain small amounts

of mostly short-lived radioactivity it is often compacted or incinerated before disposal. 90% of the volume but only 1% of the radioactivity

Intermediate level: higher amounts of radioactivity and may require special shielding resins, chemical sludge, and reactor components, as well as

contaminated materials from reactor decommissioning 7% of the volume and has 4% of the radioactivity

High level: may be the used fuel itself or the principal waste from reprocessing it 3% of the volume but 95% of the radioactivity

Whether used fuel is reprocessed or not, the volume of high-level waste is modest, - about 3 cubic meters per year of vitrified waste or 25-30 tons of used fuel for a typical large nuclear reactor. http://www.world-nuclear.org/education/wast.htm


Temporary storage of fuel rods Most nuclear power plants

have a temporary storage pool next to the reactor.

The pool is filled with boric acid, which helps to absorb some of the radiation given off by the radioactive nuclei inside the spent rods.

The spent fuel rods are supposed to stay in the pool for only about 6 months, but, because there is no permanent storage site, they often stay there for years.http://library.thinkquest.org/17940/texts/nuclear_waste_storage/nuclear_waste_storage.html

http://library.thinkquest.org/17940/texts/nuclear_waste_storage/nuclear_waste_storage.html

Dry-cask storage containers

Another method of temporary storage because of the overcrowding of pools

It is used after the waste has already spent about 5 years cooling in a pool.

It entails taking the waste and putting it in reinforced casks or entombing it in concrete bunkers.

The casks are also usually located close to the reactor site.http://library.thinkquest.org/17940/texts/nuclear_waste_storage/nuclear_waste_storage.html


Permanent fuel storage/disposal

Bury under the ocean floor

Store underground

Shoot into space

Deep geological disposal little groundwater flowing

through little geological activity1



Yucca mountain, Nevada

Extremely dry area of Nevada

The Yucca Mountain Deep Geological Repository is projected to be ready by the year 2010

The casks will be buried about 1500 feet underground



New nuclear power technologies

Reprocessing: the missing step one of the major transuranic wastes, 239Pu, is extracted from the

spent fuel rods. plutonium-239 is fissile and can be reused in power plants.

High-temperature breeder reactors The transuranic elements are bigger than uranium and generally

don't fission in a regular reactor. However, if placed in a high-temperature reactor in which the neutrons are much more excited, there is a much better chance that they will fission.

In a reactor being developed by Argonne National Laboratory, almost 100% of the transuranic nuclear wastes produced through neutron capture can be caused to fission.

The fission products created have shorter half-lives and are not as dangerous.

Fuel is not weapons grade quality.http://library.thinkquest.org/17940/texts/nuclear_waste_storage/nuclear_waste_storage.html


Recycling nuclear fuel

104 power reactors in the US: 20% of the nation's electricity

95% of the used fuel could be recycled for future use

Over the past four decades, America's reactors have produced about 56,000 tons of used fuel. That "waste" contains roughly enough energy to power every U.S. household for 12 years.

http://ehp.niehs.nih.gov/members/2005/113-11/focus.html

Masked student protestors voice their opposition at an antinuclear rally.

Beach in Kenting, ChinaNational Nuclear Power Station No. 3

in the background


Recycling nuclear fuel: The French do it, why can't oui?

France has embraced nuclear energy and now obtains 80% of its electricity from nuclear power.



Obstacles to recycling nuclear fuel The US developed the technology to recycle the nuclear fuel decades ago, then

barred its commercial use in 1977.

Anti-nuclear fear mongering has proved baseless. The French have recycled fuel like this for 30 years without incident: no terrorist attack, no bad guys stealing uranium, no contribution toward nuclear weapons proliferation, and no accidental explosions.

http://www.heritage.org/press/commentary/ed010108d.cfm

http://www.heritage.org/press/commentary/ed010108d.cfm

Basics of nuclear energy

How to educate the students

http://www.cpepweb.org/nuclear_sm_large.html

RadiationLesson plan

http://www.nrc.gov/reading-rm/basic-ref/teachers/unit1.html



Objectives

Teacher To help students become more literate in the benefits and

hazards of radiation. To stimulate student interest in the biological effects of radiation. To ensure students understand how nuclear energy is generated.

Student Distinguish between natural and man-made radiation. Detect and measure radiation using a Geiger counter. Investigate the "footprints" of radiation using the cloud chamber. Describe the principle of half-life of radioactive materials and

demonstrate how half-lives can be calculated. Identify and discuss the different types of radiation.

Beginning of class

Note: Give each student a 5x7 index card as he/she enters the classroom.

Greeting...

"Radiation" (written on the board)

When you see or hear this word what do you think about? What do you think it means?

I would like you to share your thoughts with me by writing on the card what you thought about when I wrote "radiation" on the board. Do not put your name on the card!

[Collect the cards and mix them up. Read several out loud to the class and stimulate discussion on each. Do not attempt to connect any child with a particular note. Write key words from student opinion on the board for future reference.]

Introduction

Radioactive materials are composed of atoms that are unstable.

An unstable atom gives off its excess energy until it becomes stable.

The energy emitted is radiation.

We measure ionizing radiation in units called millirems.

We can classify radiation as being either natural and man-made.

Man-made radiation

Radioactivity

Shielding

Biological effects

Large amounts of radiation -- far above the levels encountered in daily life -- can produce cancer and genetic defects in living organisms. Radiation causes damage and alters the body's normal cells and normal cell function. This breakdown in normal cell function may result in an uncontrolled growth of cells, hence the potential for malignant/cancerous tumors.

Experiment A: The Cloud Chamber

Materials

Pitch blende (UO2)

Ethanol

Dry ice

Gloves and goggles

Petri dish

Black felt

Flashlight

Styrofoam plate

Warning: Gloves must be worn when handling uranium! Do not ingest or inhale any free flowing powder! Dry ice should not be held for longer than few seconds when wearing rubber gloves. Dry ice will burn, so do not touch with bare hands.

Procedure

Place the radioactive source in the center of the Petri dish that is painted with black spray paint and lined with a strip of black felt. Cover the dish with a clear plastic lid and place on a block of dry ice. Shine a flashlight through the transparent lid and observe short, dense alpha particle trails be emitted from the radiation source. The angle of light may have to be adjusted for better viewing.

Questions

Why are elements that break apart called unstable?

How do things become less radioactive as time goes by?

What materials are best for shielding?

Gamma radiation, a powerful type of radiation emitted from some radioactive isotopes, has no weight. What other types of radiation particles have no weight?

Because you could not see the radiation, what kind of observation did you experience?

What is happening to the radioactive source?

What radiation "footprints" did you see? Describe them.

paula l. diaconescu

Documents