APES: Ch 15 Geologic Resources: Nonrenewable Energy part 2

Decommissioned

life span of nuclear power plants is typically about 40 years; most parts of power plant must be taken apart and disposed of as radioactive waste since they have absorbed radioactive energy for so many years

Low-Level radioactive wastes

give off small amounts of ionizing radiation and must be stored safely for 100-500 years until they don't pose an unacceptable risk to public health and safety

High-Level radioactive wastes

give off large amounts of ionizing radiation for a short time and small amounts for a long time typically for 10,000 to 240,000 years

Immediate dismantling

method proposed to decommission nuclear power and nuclear weapon plants. Materials from plant must be as high radioactive waste materials in high-level nuclear waste facilities (that still don't exist)

Mothballing

Putting up a barrier and setting up a 24 hour security system and then dismantling the nuclear power system.

Entombment

Covering the reactor with reinforced concrete and putting up a barrier to keep out intruders for several thousand years.

Breeder Nuclear Fission Reactors

Generate more nuclear fuel than they consume by converting non-fissionable uranium-238 into fissionable plutonium-239.

gangue

waste rock that must be removed before a mineral can be used

tailings

Rock and other waste materials removed as impurities when waste mineral material is separated from the metal in an ore.

smelting

The process by which ore is melted to separate the useful metal from other elements.

cyanide heap leaching

Level entire mountains and then use a highly toxic chemical to separate gold from the waste ore.

depletion time

The time it takes to use a certain fraction, usually 80%, of the known or estimated supply of a nonrenewable resource at an assumed rate of use. Finding and extracting the remaining 20% usually costs more than it is worth.

reserve to production ratio

The number of years that proven reserves of a particular nonrenewable mineral will last at current annual production rates

acid mine drainage

Pollution caused when sulfuric acid and dangerous dissolved materials such as lead, arsenic, and cadmium wash from coal and metal mines into nearby lakes and streams.

dredging

Chain buckets and draglines scrape up underwater mineral deposits

spoils

Unwanted rock and other waste materials produced when a material is removed from the earth's surface or subsurface by mining, dredging, quarrying, and excavation.

mountain top removal

Type of surface mining that uses explosives, massive shovels, and even larger machinery called draglines to remove to expose seams of coal underneath a mountain.

net energy

The total amount of energy available from an energy resource minus the energy neded to find, extract, process, and get that energy to consumers

anthrocite

Highly desirable coal because of its high heat content and low sulfur content. Supplies are limited in most areas.

boiling water reactor

a nuclear reactor that uses water as a coolant and moderator. The reactor core water turns to steam and then drives a steam turbine.

pebble bed reactor

reactor that reduces chances of a runaway chain reaction by encapsulating uranium fuels in tiny heat resistant ceramic spheres

fuel assembly

A bundle of hollow metal rods containing uranium oxide pellets; used to fuel a nuclear reactor.

fuel fabrication

Enriched gas is converted to a uranium powder form and formed into pellets that are then installed in fuel rods

milling

Uranium ore is crushed and concentrated. This material is now yellowcake, when its removed, tailings are left over. Tailings contain same radioactive material and must be disposed properly

enrichment

The process by which uranium ore is refined after mining to increase the concentration of fissionable U-235