Lecture 1: Introduction Flashcards
Name four issues with nuclear energy.
Health effects (radiation causes cancers)
Accidents
Waste (remains dangerous forever)
Economics (expensive)
Name four accidents, their country of location, and year of occurrence.
Windscale - Cumbria, UK (1957)
Three-mile Island - Pennsylvania, USA (1979)
Chernobyl - Ukraine (1986)
Fukushima - Japan (2011)
Name four variations of ionizing radiation from heaviest to most penetrating.
Alpha
Beta
Gamma (x-rays)
Neutrons
What is the most ionizing type of radiation?
Alpha
What is the unit of ionizing radiation dose?
Sievert (Sv)
What types of ionizing dosages are ingested?
Iodine, Caesium & Strontium
Why are potassium iodine tablets prescribed following nuclear power plant radiation emergencies?
To flood the thyroid with non-radioactive iodine therefore blocking radioactive I-131 from being absorbed and causing cancer.
In general, what is the consensus about the effect of low dosage?
No conclusive results; some positive, some negative.
What is the linear no-threshold hypothesis (LNTH) and how was it established?
The risk of harm from radiation exposure is directly proportional to the dose received, without any safe threshold.
Studies of industrial and medical workers exposed to high doses of radiation. Furthermore, studies of survivors following the atomic bombings of Hiroshima and Nagasaki during World War II provided insight to the long-term effects of radiation exposure. The incident provided the greatest quantity and breadth of data.
Give examples of low, medium, and high levels of radiating nuclear waste.
Low: Lab equipment, clothing, building materials
Medium: Power station parts, storage vessels
High: Used fuel
What defines low, medium, and high levels of nuclear waste?
Low: Alpha, beta or gamma waste
Medium: Above LLW threshold but no heat
High: Above LLW and heat
What are the most significant economic considerations?
Expensive upfront investment and operational costs.
Long build time.
Which countries are leading the current nuclear trend?
USA (highest capacity)
France (greatest % of energy production)
China (highest construction uptake)
What are potential profitable strategies to make the most from nuclear power plants?
Uprating - Increase generating capacity above predictions so long as safe.
Life extension - continue operation beyond expected lifetime.
Describe a brief summary of the history of nuclear energy?
Discovery of x-rays and radioactive elements for medical purposes.
Nuclear fission applied to build atomic bomb (WW2).
Nuclear fission used for electricity generation & peaceful development internationally agreed, however reactors built to produce plutonium for bombs.
Investment into technology with mixed reactions.
What is used to produce atomic warfare and why?
Plutonium - fission of Pu produces more neutrons thus causing a more explosive chain reaction.
Define fission:
Nucleus splits into two or more smaller nuclei, along with the release of energy and typically one or more neutrons causing a chain reaction.
Define fusion:
Two or more atomic nuclei combine to form a single, heavier nucleus, accompanied by large release of energy.
Name and describe the cycle used to generate electricity from nuclear energy:
Rankin Cycle:
Cold water pumped into heat exchanger to convert into steam and turn a turbine released into a condenser once all work done.
Name three fuel types:
Natural uranium metal
Uranium dioxide
Thorium
What are the two different neutron cycle types?
Thermal & Fast
Name four types of coolant and their variations:
Water (light / heavy)
Gas (CO2 / helium)
Liquid metal (sodium / lead)
Molten salt
Name the fuel type, neutron cycle, coolant, and moderator for a PWR:
Pressurised water reactor:
UO2
Thermal
Light water
Water
2 loops
Name the fuel type, neutron cycle, coolant, and moderator for a AGR:
Advanced gas cooled reactor:
UO2
Thermal
CO2 gas
Graphite
2 loops
Name the fuel type, neutron cycle, coolant, moderator and number of loops for a BWR:
Boiling water reactor:
UO2
Thermal
Light water
Graphite
1 loop
Name the fuel type, neutron cycle, coolant, moderator and number of loops for a LMCF:
Liquid metal cooled fast:
UO2
Fast
Liquid metal (sodium)
NO MODERATOR (TRICK Q - FAST)
3 loops
Name the fuel type, neutron cycle, coolant, moderator and number of loops for a PHWR:
Pressurised heavy water reactor:
UO2
Thermal
Heavy water
Heavy water, also known as deuterium oxide (D2O)
2 loops
What is the general trend of energy price for different generations types?
Nuclear increasing, renewable decreasing, coal constant
Where does Germany stand with nuclear energy?
Phasing out nuclear power following the Fukushima disaster.
What is the main type of reactor in the UK?
AGR
What percentage of the world’s electricity is produced by nuclear energy?
~10%
