Radiation

Peter Lee

Radiation

• Radiation is energy that may take such forms as light, or tiny particles much too small to see. Visible light, the ultra-violet light we receive from the sun and from sun-beds, and transmission signals for TV and radio communications are all forms of radiation that are common in our daily lives.

Types

• There are two types of

radiation, non-ionizing

radiation and ionizing

radiation

Non-ionizing

• Radiation that does not carry enough energy to ionize an atom or molecule (not enough to remove an electron)

• This includes radio, infrared, microwave and anything less then ultra violet

Warning – Non Ionizing Radiation

Effects – Non ionize

• Does not cause Mutations

• Most of the effects are similar to mild burns and itching

• Worse case scenario – An extreme burn similar to being set on fire

Ionize Radiation

• Radiation that carries enough energy to cause an electron to detach and leave

• Anything ultraviolet and higher

Effects

• Mutation in cells

• Cell Damage – permanent/temporary

• Tissue Damage – permanent/temporary

Warning – Ionizing Radiation

Measuring Radiation / Regulations

• Gray (Gy) – one joule of energy per one kilogram of tissue

• Sievert (Sv) is used in setting radiological protection standards. One gray of beta or gamma radiation has one sievert of biological effect, one gray of alpha particles has 20 Sv effect and one gray of neutrons is equivalent to around 10 Sv (depending on their energy)

• Radiation is regulated by the Department of Energy (DOE) and the Environmental Protection Agency (EPA(, and they the limitations on exposure (currently 2-3 mSv/year)

Doses and effects• 2 mSv/year Typical background radiation experienced by

everyone (av 1.5 mSv in Australia, 3 mSv in North America).• 2.4 mSv/year Average dose to US nuclear industry

employees.• 20 mSv/year Current limit (averaged) for nuclear industry

employees and uranium miners.• 100 mSv/year Lowest level at which any increase in cancer is

clearly evident. Above this, the probability of cancer occurrence (rather than the severity) increases with dose.

• 1,000 mSv/cumulative Would probably cause a fatal cancer many years later in 5 of every 100 persons exposed to it (i.e.. if the normal incidence of fatal cancer were 25%, this dose would increase it to 30%).

• 1,000 mSv/single dose Causes (temporary) radiation sickness such as nausea and decreased white blood cell count, but not death. Above this, severity of illness increases with dose.

• 5,000 mSv/single dose Would kill about half those receiving it within a month.

• 10,000 mSv/single dose Fatal within a few weeks.

Nuclear Energy

Alternative Or Last Resort

• The Cost of energy has been slowly rising and fossil fuels are starting to wear dry. An alternative is Nuclear energy.

• Nuclear energy provides a cheap source of energy as well as electricity. It is more productive then coal and it is possible to generate 2000 time as much energy from nuclear the with fossil fuels or coal

Trade offs

• Nuclear power plants are more expensive to build and take a long time to build

• Nuclear Energy – less for more• Creates low or no CO2, but does produce

radioactive materials• Radioactive materials can break down and

become stable – Takes a LONG time• Accidents are more damaging, (meltdowns,

failures)• Radioactive Substances have more severe

health effects

Method

• Nuclear energy is the method of getting energy by fission or fusion

• Fission is the process of breaking an atom to split into two smaller atoms

• Fusion is the process by combining two atoms

• The resultant mass is smaller then the starting mass, loss mass I converted into energy (E=MC2)

Cost

Building and maintaining of the plant – workers, equipment

Cost of Production Example:Uranium:8.9 kg U3O8 x $53 = US $472 Conversion:7.5 kg U x $12 = US S$90Enrichment:7.3 SWU x $135 = US $985Fuel fabrication: per kg = US $240 Total, approx: US$ 1787

Uranium can produce 2,000 times electricity that coal can produce, but there is A LOT more coal then uranium

Nuclear Non-Proliferation Treaty

Countries that joined the treaty agreed to no longer use or manufacture Nuclear weapons

Countries are allowed to devoloped nucler energy during peacetime, to benefit the people

Nuclear Regulatory CommissionNuclear Regulatory Commission (or NRC) is a United States government

agency that was established by the Energy Reorganization Act in 1974, and was first opened January 19, 1975. The NRC took over the role of oversight of nuclear energy matters and nuclear safety from the AEC, or Atomic Energy Commission.

Waste

• Radioactive waste can be solid, liquid, or gaseous waste that contains radionuclide.

• Low Level Radioactive Waste (LLW), LLW often contains small amounts of radioactivity dispersed in large amounts of material.

• High Level Waste (HLW), Depleted Uranium, is highly radioactive material from the reprocessing of spent nuclear fuel. HLW includes spent

nuclear fuel, liquid waste, and solid

waste derived from the liquid.

Disposal

• Low Level Radioactive Waste (LLW), can be stored and they do not take as long of a time to decay, can be stored in storage or warehouses

• High Level Waste (HLW), has to be stored in a secure place and must be checked on. It is usually stored in a secure landfill that is very deep and has lots of layers. Can cause a lot of damage