Climate Change and Energy Production

Stored energy (solar) from resources that exist in fixed amounts in the earth's crust. These can be depleted and are not replenishable by natural processes within a human time scale

Energy from resources that can be replenished rapidly (hours to decades) through natural processes as long as it is not used up faster than it is replaced.

Total amount of useful energy available from a resource, minus the energy needed to make the energy available in the first place.

 Energy obtained per unit energy used to obtain it

It takes high quality energy to get high quality energy. Energy is expended in the process of pumping oil from the ground, refining it, transporting it.

Some high quality energy is wasted at every step along the way. Entropy. Things get more chaotic as time goes on. 

The ITER Project’s JET (Joint European Torus), the first device to create controlled fusion power, has delivered its final plasma after 40 years of operation. Now, in early 2024, it will be moving on to the next stage -- repurposing and decommissioning, which will last until 2040. In the meantime, ITER has continued to update the main ITER project, one recent development being in Korea. The Korea Institute of Fusion Technology recently equipped its KSTAR with new diverter technology. This new diverter can take in twice as much of a thermal load than its predecessor. The ITER start for creating plasma is scheduled for late 2025.

The biggest breakthrough in recent years occurred in December 2022, when scientists at the US National Ignition Facility were able to achieve ignition: a fusion reaction that produced more energy than it consumed. This experiment was repeated again at the Lawrence Livermore National Laboratory, who also was able to achieve ignition and produced an even higher yield than the one in December 2022. Just recently in December 2023, the world’s largest experimental nuclear fusion reactor has been inaugurated in Japan. This project is a collaboration between Japan and the European Union and is a forerunner for ITER.

ULTIMATE SOURCE: atomic nuclei in decay

• How does a Nuclear Fission Reactor Work?

  • Controlled/timed nuclear fission reaction within a sealed reactor (unlike nuclear weapons)

    • Many types of reactors - light water reactors most common (relatively cheaper)

      • LWRs are power by uranium ore, which is packed as pellets into fuel rods

        • Within uranium atoms, nuclear binding energy is released in the form of electromagnetic radiation

        • This radiation is used to turn liquid water into steam, which then spins a turbine

        • Vast amounts of freshwater used to moderate temps within these systems - huge cooling towers - reactors mainly built on or near water

    • But, these are also problematic - old tech (60s, 70s), less than 40% inefficient

• Low impact, low carbon energy (no combustion)

• “Nuclear power plants discharge 50% more waste Rheat to the atmosphere through cooling towers or to a water body than coal-fired plants.” (NLM)

  • Temperature variations affect metabolic rates of organisms and dissolved oxygen levels. Can often increase the susceptibility of organisms to toxic substances. (IntechOpen)

• The use of cooling towers, man made ponds, etc, help to minimize these impacts. Water may also be treated before being released. Of course, however, this does add to expenses

• This ScienceDirect article suggests that thermal pollution is usually “small or even insignificant”. 

• Nuclear fuel is energy dense, so the amount of waste produced is relatively small

  • “On average, the waste from a reactor supplying a person’s electricity needs for a year would be about the size of a brick. Only 5 grams of this is high-level waste – about the same weight as a sheet of paper.” (World Nuclear Association)

• Storage and disposal

  • Often kept in wet storage to be cooled, diminishing heat and radioactivity; then typically either disposed of through recycling or direct disposal. Direct disposal - placed in a repository underground in sealed canisters.

    • Will remain weakly radioactive for a few hundred thousand years, but will likely cause no harm to human health whatsoever

• Capital costs: 60% site preparation, engineering, manufacturing, construction, commissioning, and financing

• Operating costs: fuel costs (from uranium mining to fuel fabrication), maintenance, decommissioning, and waste disposal

  • Capital cost far higher for nuclear than for nonrenewables like coal - nuclear plants are more technically complex, stricter safety standards

  • Newer, more advanced reactor designs have improved operational efficiency and thes cheaper operating costs

• NRDC

  • When countries have access to the technology/resources for nuclear power, they have the capacity to also manufacture warheads

    • “In a number of countries, peaceful nuclear materials and equipment have been diverted to secret nuclear weapons programs.”

  • UN Treaty on Non-Proliferation of Nuclear Weapons (1970)

    • Near-universal participation

    • “...countries with nuclear arsenals…must negotiate and reduce their nuclear weapons stockpiles, ultimately eliminating these weapons of mass destruction”

      • However, nuclear weapons are currently increasing in quantity

• Typical reactor produces 1 GW of energy - high capacity for energy generation (Energy.gov)

  • Large amounts of energy are needed for each step in the reactor cycle, significantly lowering net energy yield

• Outside Harrisburg, PA: nuclear power plant

  • Accident: cooling system broke down, some radioactive steam escaped into the air

    • Inside the too-hot reactor, a potentially explosive air bubble developed

  • High radiation ratings in the plant area - pregnant woman and children had to evacuate after 3 days.

    • Five years later, the reactor was opened up and half the fuel was found to have melted

    • Overall, there were no casualties, but the meltdown could have been worse than anticipated

    • Cleanup took nearly a decade, extremely expensive

• April 26th, 1968: Chernobyl, Ukraine

  • Some operator actions - including disabling of automatic shutdown mechanisms - reactor was unstable

  • Massive power surge when control rods were inserted into reactor

    • Caused a steam explosion, then a second explosion. The graphite and fuel fragments from the explosion started a number of fires

• Immediate impact: massive release of radiation into surrounding environment. The firefighters who responded to the scene experienced acute radiation syndrome (ARS)

• The town of Pripyat was evacuated on April 27. By May 14th, 116,000 people that had been living within 30km radius had been evacuated and later relocated. Belarus, Russia, and Ukraine experienced the most significant effects of the radiation, but the fallout did spread throughout Europe as a whole

• Earthquake - March 11, 2011

  • Generated tsunami waves that damaged the backup generators at the Daiichi plant (constructed in the 1970s)

  • Loss of power caused cooling systems to fail. Because of the lack of cooling, heat caused the fuel rods in the first 3 reactors to overheat and partially melt down

    • Explosions from buildup of pressurized hydrogen gas

    • Another explosion March 15

• Surrounding area evacuated

• Workers attempted to cool the plant with water, which temporarily slowed the release of radiation

• Radiation began appearing in local food and water supplies

• Placed on the same severity level as Chernobyl

Domestic: US approves a non-water-cooled nuclear reactor

• Construction permit for a new nuclear test reactor to be built in Oak Ridge, Tennessee

  • First non-water-cooled reactor to be approved for construction in U.S. in over 50 years

  • Instead of water, this reactor would utilize molten salt as a cooling agent

  • Project received $303 million of Department of Energy funding

  • The project will require a separate operating license after its built from the US Nuclear Regulatory Commission

• To promote the development of small modular reactors, the European Commission has launched an industrial alliance

• These SMRs will be less expensive and time consuming to build

• Several projects are being planned throughout Europe - for example a cluster of six is being planned for the site of a decomissioned coal plant in Romania

Natural:

1. The Earth’s orbit

2. The Sun’s temperatures

3. Volcanic activity

Anthropogenic:

1. Deforestation

2. Ozone pollution

3. Aerosol pollution

4. Greenhouse gases

The Intergovernmental Panel on Climate Change - the United Nations body for assessing science relating to climate change.

To provide updates on the state of scientific/technological/socioeconomic knowledge on climate change, potential impacts, and what can be done to reduce the rate of climate change.

“The IPCC was created to provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options.”

Current Mitigation Progress, Gaps and Challenges

Policies and laws addressing mitigation have consistently expanded since AR5.

Global GHG emissions in 2030 implied by nationally determined contributions (NDCs) announced by October 2021 make it likely that warming will exceed 1.5°C during the 21st century and make it harder to limit warming below 2°C.

There are gaps between projected emissions from implemented policies and those from NDCs and finance flows fall short of the levels needed to meet climate goals across all sectors and regions.

Ultimate source: sun