Energy from Nuclear Power

Nuclear energy Benefits Concerns: Status Nuclear fission Nuclear fusion Benefits Concerns: Cost HealthSafety Waste disposal Weapons Status

NUCLEAR FISSION “fission” = splitting of uranium atoms widely used for producing electricity

Nuclear Fission: Stages & Problems Mining of uranium High incidence of lung cancer among miners Radioactive tailings and debris nearby 2) Milling (extracting) uranium from the ore (rock) Piles of debris Equipment can’t be decontaminated 3) Enrichment of uranium: Increases % of usable uranium from 0.7% to 2.5%. Much uranium waste. Energy intensive. http://www.abc.net.au/news/2012-12-10/ranger-uranium-open-cut-mining-ends-era/4418596

Nuclear Fission: after enrichment: Step 4) Manufacture fuel pellets Each: energy of a ton of coal (half a train car)

Nuclear Fission Step 5) Fill 12’ fuel rods with pellets in reactor core Fuel rods last 3-6 years Then radioactive waste that needs disposal

Step 6) Produce electricity using uranium fuel in power plant

Step 7. (Sometimes) Reprocessing of Used Fuel Gets more energy from used nuclear fuel and reduces waste But produces weapons-ready plutonium Extracts fissionable plutonium from spent fuel In Japan and Europe; not US (cost ahd risk)

Step 8. Storage & Disposal of Radioactive Waste ……………But where?

Nuclear fusion (vs. Nuclear fission) Fuses nuclei of abundant deuterium and tritium, abundant in sea water Doesn’t require uranium! We want this to work! No waste. But more energy used than produced …but: New experimental technologies to create necessary high temperatures with stability

Nuclear fusion: experimental technologies under investigation Tokamak technology: biggest experiment: $18 billion fusion reactor, ITER, planned since 2008, is under construction in France $$ from France, China, Russia, Japan, South Korea, EU, USA.

Nuclear energy Benefits Concerns: Status Nuclear fission Nuclear fusion Benefits Concerns: Cost HealthSafety Waste disposal Weapons Status

Nuclear Power: Benefits Energy in one pound uranium = 15 freight cars of coal No NOX, SOX, mercury, SPM Virtually no greenhouse gases

Benefits of Nuclear Power Minimal carbon emissions Many smart, prominent environmentalists and scientists: nuclear power is essential to fight global warming

Lives Saved by Nuclear Power Prominent study: low death rate compared with fossil fuels Peer-reviewed article by renowned climate scientist James Hansen, 2013.

Nuclear Power MAJOR CONCERNS: Cost Safety & health Waste Nuclear proliferation (weapons) Protest in France, March 18, 2014

Concern #1 Re: Nuclear Power: Expense Expensive to build reactor, mine & enrich uranium, manufacture fuel rods, operate reactor Cost 4X as much as energy fr/coal or wind USA has spent $150 billion (subsidies) in 50 years (vs. $5 billion on renewable research and development) Private industry interest is very low, even with new government incentives (like exemption from liability). AND: costs of waste management: hard to estimate in absence of solutions Accidents are very costly to clean up

Concern #2 About Nuclear Power: Human Health and Safety Radioactivity causes cancer Mining & mill tailings Enrichment by-products Transporting uranium Power plant accidents & terrorist attacks Safe waste disposal difficult NOTE: modern nuclear plant design quite safe

Nuclear Power Plant: Major Accidents Three Mile Island, Pennsylvania, 1979 Clean up cost so far $1.2 billion; cost $700 million to build Chernobyl, Ukraine: 1986 Gas explosions and fire in core 3500-32,000 deaths plus 500,000 exposed Thyroid cancer 100x pre-accident levels 62,000 sq miles contaminated (size of Florida) Cost $358 billion Fukushima , Japan: 2011

Nuclear Power – Fukushima Disaster Earthquake: worst ever for Japan. power lost, automatic shutdown, backup generators kicked in Huge tsunami: 30’ (seawall designed for 20’) generators failed; cooling system stopped; heat built up; explosion

Disposal of nuclear waste No satisfactory solution Temporary storage facilities at power plants Are these sites secure from terrorism? Is permanent storage possible? If we doubled nuclear energy: need a huge new repository every 4 years But we have NO long-term secure storage facilities NIMBY Yucca Mountain, Nevada, designated by Congress 1987…but:

Yucca Mountain, Nevada Proposed Radioactive Waste Disposal Site Tectonically unstable; not in crystalline rock Rejected by Obama 2009.

Disposal of nuclear waste No satisfactory solution Low-level radioactive wastes: ocean dumping until 1970; now two landfills. Dangerous 100-500 years High-level radioactive wastes: liquids & spent fuel rods: high cancer danger 10,000 years

Status of Nuclear Power 2012

Status of Nuclear Energy After Fukushima: Recent Policy Changes Many nations: banned or stopped construction; some are closing existing reactors USA: Permit for building new reactors: 2012 US encouraged new reactors, offering liability protection and subsidies But in 2013: 6 proposed new reactors cancelled; 5 old reactors closed

Nuclear energy Benefits: Concerns: Virtually no carbon emissions Energy from small volume of materials Concerns: Cost Health and safety at each stage of the fuel chain No solution for waste disposal Which is more dangerous: global warming or nuclear power?