Nuclear Power

Introduction

• Nuclear power plants provide about 17 percent of the world’s electricity.

• There are more than 400 power plants in the world, with over 100 of these in the united states.

• France uses nuclear energy as its main source of electricity. 75%.

• They produce 25% of Britain's electricity.

What is Nuclear Energy and How does it Work?

• Nuclear energy uses uranium which is a naturally occurring radioactive substance.

• The uranium is used because if a free neutron collides with the nucleus of a Uranium atom, the nucleus splits into two smaller atoms plus one free neutron. This is called fission.

• This free neutron can then cause another fission to occur (a chain reaction). As the two new atoms weigh less than the original Uranium atom, an enormous amount of energy is also released.

• The energy produced from the fission is then used as a heat source to heat up water which creates steam that turns a turbine that spins a generator to produce electricity.

Sustainable Advantages- Futurity

• The Earth’s temperature is already going to rise by 2 degrees, a change needs to take place to stop it potentially rising to a 6 degree increase

• The safety of the plants is only set to increase due to much international research

• Cancer mortalities are hugely exaggerated• Alternatives can be very expensive

Environmental Advantages

• Mitigates the greenhouse effect

• Some governments need to meet the standards of the Kyoto Protocol

• Need to eliminate the possibility of major cities flooding

Equity and Social Justice

• Nuclear energy is in abundance and is widely distributed

• It is the poorer areas like Bangladesh which lie at sea level who will suffer, increasing inequality

Disadvantages -Futurity

• Problems with storing waste for an indefinite time• Potential target for terrorist attacks• The increase in research into nuclear energy could aid

the possibility that some countries could lead to the proliferation of nuclear weapons

• Very expensive• Coal power is cheaper, leading to many NIC’s choosing

that option• High capital costs of switching to nuclear• Issues with reliability

Environmental Disadvantages

• The nuclear reactors need cooling, therefore GHG’s are produced water vapour

• Transport to and from mine sites create GHG’s

• Nuclear energy cannot be used alone due to reliability and peak energy times needing to be provided for

Public Participation

• It isn’t popular with the public

Causes Inequity• It is such an expensive option to set up

that many LEDCs won’t see it as an option, or if they do safety precautions may be lax

Three Mile Island

Susquehanna in Dauphin County, Pennsylvania, near Harrisburg.

America

Introduction

• Most serious in U.S. commercial nuclear power plant operating history

• Occurred March 28th 1979.

• Happened Three Mile Island Unit 2 nuclear power plant near Middletown.

Causes

• Equipment malfunctions

• Design related problems

• Work errors

Sequence of Events Leading to the Accident

• 4am plant experienced a failure in the secondary, non- nuclear section of the plant

• The turbine and then reactor automatically shut down. Causing pressure in the primary system to increase.

• To decrease this pressure a pilot operated relief valve was opened. This was not closed when the pressure lowered back to a certain point.

• Operating signals failed to show valve was still open and this resulted in cooling water pouring out the stuck open valve and caused the core of the reactor to overheat.

• As coolant lowed from the core through the pressurizer the instruments available to reactor operators provided confusing information.

• Due to lack of adequate cooling nuclear fuel over heated to the point where the zirconium cladding ruptured and the fuel pellets began to melt. One half of the core melted during the early stages.

• The plant had suffered a severe meltdown.

Health Consequences

• There were very little consequences that could be proven affecting health.

• The collective dose to the community from the accident was very small.

• Thousands of tests to the air, water, vegetation soil and food stuff found little contamination and negligible effects on health or environment.

Impacts of the Accident

• Upgrading and strengthening of plant design and equipment requirements

• Identifying human performance as a critical part of plant safety

• Improved instruction to avoid the confusing signals that played the accident.

• Enhancement of emergency preparation• Regular analysis of plant performance• Expansion of inspections• Expansion of international activities in order to

enhance nuclear safety throughout the world.

Chernobyl Case Study

Located in The Ukraine.

Chernobyl

Introduction

• The disaster at Chernobyl was the worst nuclear power accident the world has ever seen.

• Occurred April 25th-26th 1986.• Nuclear power plant situated 80 miles

north of Kiev.• 4 reactors and reactor number 4 was

being tested with numerous safety procedures being disregarded.

Causes of Chernobyl Disaster

• Lack of a ‘Safety Culture’

• Design fault in the RBMK reactor

• Violation of Procedures

• Communications break down.

Sequence of Events Leading to the Accident

• 25th April reactor 4 shut down for routine maintenance, however it was decided to take advantage of this to run a test.

• During the test the reactor became more and more unstable, despite efforts.

• The slowing turbines provided less and less coolant to the reactor.

• Resulted in a sudden increase in temperature caused part of the fuel to rupture,, fuel particles then reacted with the water creating a steam explosion which destroyed the reactor core. A second explosion added to the destruction two minutes later.

Health Consequences

• Increase in Thyroid cancer

• Increases in other cancers.• 30 lives were lost during the accident or within a few

months after it.• Figures from the Ukraine Radiological Institute

suggest that over 2,500 deaths were caused by the Chernobyl accident.

Psychological Consequences

• Significant increases in:

-Anxiety

-Depression

-Helplessness and despair leading to social withdrawal and loss of hope for the future.

-Other disorders attributable to mental stress

• These were a result of lack of public information available after the accident.

Social, Economic and Political Consequences

• Control measures limit industrial and agricultural activities.

• Following the accident 116,000 people had to be evacuated and between 1990 and 1995 an additional 210,000 were resettled.

• Villages had to be decontaminated and majored work carried out on infrastructure.

• Demographic indication in ‘contaminated areas’ suggest that these areas are experiencing decline.

• Effected areas suffered major disruption to normal life ad economic activity, particularly agriculture and forestry.

• A victim mentality has occurred in the area.

Environmental Consequences

• Radioactive material was widely dispersed and was measurable and resulted in effects practically over the whole of the northern hemisphere.

• In the short term lethal doses effected coniferous tress and small mammals within a 10km radius of the reactor.

• By 1989, ecosystems began t recover however there is the possibility o long term genetic effects.

Thanks for Listening!