Renewable Energy Solutions 2 Flashcards
What are two key observations to be considerate from when we consider whenre the energy can come from?
- Evaluation of risk is not simple
- Understanding relative probabilities and impacts of risk associated with the energy industry is polarised by social acceptance and awareness
Define what sustainability is in terms of Chemistry?
“Deploying atoms and energy in the most responsible way to deliver a safe environment and an acceptable quality of life for all, both now and in the foreseeable future”
Sumarise the 12 principles of green chemistry…
- It is being mindful about the atoms and energy we use
- Being mindful about the products you make and the products impacts (i.e. toxicology/degradatio)
What is the key priciple of make electricity/energy
- The generation of heat, which in turn heats water and produces steam
- The steam spins a turbine which drives a generator, resulting in electricity
What is the basic priciple of nuclear fission?
- Uranium has a nuetron shot at it which causes the atom to split, on which a lot of energy is released
- The other thing which comes out is fissionable materials which propagates a chain reaction
- This means when one single nuclear reaction causes an average of one or more subsequrnt nuclear reactions
Why does nuclear fission not meet into the green priciples of chemistry?
- Because of the harmful nature of the waste being produce, which as of current cannot be delt with
- So current stored underground for other generations to deal with
- (but cost benefit, with the loss of CO₂ which would have been produced from non-renewables for the generation of the same amount of energy)
What is the treaty on the Non-Proliferation of Nuclear Weapons (NPT)?
Uranium is only sold to countries that have signed the NPT, which was introduced on 1 July 1968 and aims to limit the spread of nuclear weapons
What is the current global demand for Uranium?
Global demand is approx. 65k metric tonnes - 370 GW power generation (10% of worlds power, 436 installations)
Why is the nuclear fission system circular?
- The fuel comes in from mining and becomes enriched, before it goes into fabrication where it is made into pellets used within the nuclear reactor
- Once it has gone through its lifetime in a reactor, it then goes into a cooling pool for a prolonger period
- It is then sealed into a steel drum where it goes to a reprocessing facility which concentrated any residual uranium + any other products which have alternative purposes
- The reprocessed uranium then goes back into the feedstock
- (circularity partly driven by saftey)
How does Nuclear fission meet the STGs?
- STG 7 - Affordable clean energy: low carbon, consistent (90% capacity) energy
- STG 9 - Industry, Innovation + Infrastructure: Advanced reactor designs, grid stability and innovation
- STG 13 - Climate Action - Lower GHG emissions, reducing reliance on fossil fuels etc
- STG 3 - Good health + Well being - reduced air pollutions
Key drawback of nuclear fission
- High upfront cots and long construction times
- Public concern over safety
- Long-term waste storage and geopolitical issues around uranium supply
Low level waste consits of 90% of all radioactive waste (by volume) and high level waste consists of 3% of all radioactive waste (by volume)
What is the difference in their total radioactivity?
Low level waste - 1% of the total radioactivity of all waste
Can be compacted into steel canisters and stored in concetre vaults underground
High level waste - 95% of the total radioactivity of all waste
Is compacted into deep geological disposal - requires >50yrs for the heat to disapate before this
What happened at Chernobyl on 26th April 1986?
- The world’s worst nuclear accident took place at Chernobyl on 26th April 1986
- One of the four reactors at the nuclear power plant, 70 miles north of Kiev, exploded at 1:23 am
What was the main challenge to deal with the clean-up from Chernobyl?
- When the immediate danger passed, containment became the main challenge
- Thousands of liquidators were brought in to cleanse the surrounding area and build a vast concrete and steel sarcophagus above the reactor to seal it off from wind and rain
What happended to nature within Chernobyl post explosion?
- Despite the last contamination of the area, scientistt have been surprised by the dramatic revivial of its wildlife
- Wild horse, boar and wolf populations are thriving, while lynx have returned to the area and birds have nested in the reactor building without any obvious ill-effects
The Chernobyl disaster released 100 times more radiation than the atom bombs dropped on Nagasaki and Hiroshima
What effect did these have?
- Much of the fallout was deposited close to Chernobyl, in parts of Belarus, Ukraine and Russia
- More than 350,000 people resettled away from these areas, but also 5.5 million remained
- Contamination of Caesium and Strontium is of particular concern, as it will be present in the soil for many years
- Traces of radioactive deposits were found in nearly every country in the northern hemisphere
The number of people who could eventuall die as a result of the Chernobyl accident is highly controversial
Why?
- An extra 9000 cancer deaths are expected by the UN-led Chernobyl forum
- Greenpea predicts more - up to 93000 extra cancer deat, with other illness taking the toll as high as 200000
- The most obvious health impact is a sharp increase in thyroid cancer
- (BUT consider the amount of people who could have died from atmospheric pollution from fossil fuels)
