Exemplar for internal assessment resource Physics for Achievement Standard 91527
Exemplar for Internal Achievement Standard
Physics Level 3
This exemplar supports assessment against:
Achievement Standard 91527
Use physics knowledge to develop an informed response to a socioscientific issue
An annotated exemplar is an extract of student evidence, with a commentary, to explain
key aspects of the standard. It assists teachers to make assessment judgements at the
grade boundaries.
New Zealand Qualifications Authority
To support internal assessment
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: Low Excellence
1.
For Excellence, the student needs to use physics knowledge to develop an
informed and comprehensive response to a socio-scientific issue.
This involves:
•
•
linking key physics ideas together to provide a coherent picture of the
physics relevant to the socio-scientific issue
analysing and prioritising the physics knowledge related to the issue to
justify the response.
The student has linked nuclear power to the generation of electricity and then
nuclear power is linked to mass deficit (1).
The physics knowledge has been analysed and prioritised by looking at the pros
and cons of nuclear power, and emphasising the importance of safety and
environmental impact over nuclear power’s high energy output per Kg (2).
For a more secure Excellence, the student could:
•
•
•
© NZQA 2015
explain the physics ideas more clearly by using equations and diagrams to
illustrate how a chain reaction occurs, use actual values to calculate the
mass deficit, consider the kinetic energy of the fission products and
elaborate on the efficiency of nuclear power by providing some appropriate
quantitative data
analyse the physics knowledge by discussing the minimum amount of fuel
required for energy generation and link this to the production of nuclear
waste
prioritise information by commenting on sources and information,
considering ideas such as validity (date, peer reviewed, scientific
acceptance), bias (attitudes, values, beliefs) and weighing up how science
ideas are used by different groups (e.g. power companies versus
consumers).
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Nuclear fission produces heat, and this heat is used to heat water and make steam. This steam powers
turbines which turn generators and these generators produce electricity. Energy is related to mass as
shown in Einstein's equation E=mc2 . Under the right conditions uranium will split into 2 smaller atoms
and will release 2 or 3 neutrons. The combined mass of these resulting particles is 99.9% of
the mass of the original uranium atom. The mass deficit of the other 0.1% of the original
mass got converted to energy. This energy is released in the form of gamma rays. These can
be stopped by thick walls of concrete, lead or packed dirt.
In my opinion I believe that nuclear power should not be used in New Zealand. I believe that
foremost the environmental benefits of low carbon emissions are heavily outweighed by the
heavily negative effects disposal of radiation will have over a long time period as well as the
danger a possible nuclear disaster presents to society both in New Zealand and
internationally. A disaster could cause pollution of water streams or soil, causing a decline in
the available farm land in New Zealand. The risk of nuclear waste polluting natural resources
like water and contaminating the air is what creates many ethical questions such as where is
it safe to store nuclear waste and will the presence of buried nuclear waste decrease the
value of property in certain areas. A disaster like this would result in a sharp decline of New
Zealand's agricultural sector, negatively affecting the economy causing tax to rise and further
political unrest from opposing parties. I believe the presence of these negative environmental
effects will dramatically decrease the image of New Zealand as an environmentally-clean
country decreasing another important sector of the economy, tourism.
I also believe that the economic benefits of nuclear power's high energy per Kg characteristic
would be heavily shadowed by the government and public's argument that hydroelectric
dams would have dramatically cleaner production and far more bountiful resources (provided
by the presence of so many lakes and rivers in New Zealand). I admit the absence of fossil
fuels in the future may cause an increase in the demand for cleaner forms of energy. This
leads to my argument that until nuclear power is further developed and far safer than it is
currently I do not wish to see it being utilised in New Zealand. I believe for New Zealand to
prepare for the eventual depletion of fossil fuels it needs to be investing in innovations in safe
and clean forms of energy such as solar or wind energy production.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: High Merit
2.
For Merit, the student needs to use physics knowledge to develop an informed
and reasoned response to a socio-scientific issue.
This involves:
•
•
explaining how or why the key physics ideas relate to the socio-scientific
issue
justifying the personal response using relevant physics knowledge to
explain why the position and the action(s) have been chosen.
The student has explained how nuclear fission is used to generate nuclear power
which creates nuclear waste (1), and justified their personal position using the
possibility of radioactive materials escaping as a result of New Zealand’s size and
geographical features (2).
To reach Excellence, the student could relate the key physics ideas more clearly
to the socio-scientific issue. For example, the student could relate nuclear power
generation to the concept of binding energy and the creation of nuclear waste.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
A nuclear power plant uses controlled nuclear fission and heat produced by a nuclear fission
reaction uses Uranium-235 as fuel. The heat is used to boil water; the steam from the boiling
water turns a turbine which then generates electricity. A nuclear power plant uses much less
fuel than a fossil fuel plant (works same as nuclear plant, except uses oil or coal as f u e l ) .
"It takes 1700 kilograms of coal to produce the same amount of electricity as 1 kilogram of
nuclear uranium fuel". This gives a huge advantage for nuclear plants as energy can be
produced much faster, though New Zealand, unlike Japan, is a small country and our energy
demands aren't that high. Uranium is processed into fuel rods and loaded into nuclear power
reactors where it undergoes the nuclear fission reaction. This increases the radioactivity due
to the formation of extremely radioactive elements known as fission products, such as
cesium and strontium, resulting from the splitting of uranium-235 atoms. Heavier elements
are also formed including plutonium. "Each 1000 megawatt nuclear power reactor annually
produces about 500 pounds of plutonium, and about 30 metric tons of high-level waste in the
form of irradiated fuel." NZ does not need these wastes to deal with and become a risk in our
environment. The half-life of a radioactive element is the amount of time it takes for one half
of the quantity of that element to decay. Plutonium-239 has a half-life of 24,400years. It is
dangerous for a quarter million years, or 12,000 human generations. As it decays, uranium235 is generated which has a half life of 710,000 years. Thus, the hazard of radiation will
continue for millions of years. These wastes must be shielded for centuries and isolated from
the environment. While high-level nuclear waste is produced in relatively small quantities,
after half a century there is still no proven safe disposal method and management will be
required for hundreds of thousands of years (The potential issues from nuclear containment
faller include increased risks of cancer), Years after the Fukushima accident, there have also
been reports that have shown an increase in risk for specific cancers of the population inside
the Fukushima area. This includes a 4% increase for solid cancers in females, a 6% increase
in breast cancer in females, and a 7% increase in leukaemia for males. The risk of thyroid
cancer in females has risen from a lifetime risk of 0.75% to1.25%. This increased risk of
cancers is not worth nuclear power; "Each year globally, 12.7 million people learn they have
cancer, and 7.6 million people die from the disease."
(Retrieved from http://www.cdc.gov/features/worldcancerday/ on 24.5.1)
Nuclear power in New Zealand is a double-pronged sword. On the one hand, it is a clean and
efficient energy production method that does not rely on the burning of fossil fuels and therefore
does not produce harmful CO2. This is important to consider as nuclear power does not
produce any harmful emissions and also, taking into account, the unwillingness of New Zealand
citizens to mine the land, coal and other such resources are likely to soon be in short supply.
Nuclear power isn't affected by fluctuating gas prices and "According to the Nuclear Energy Institute,
the power produced by the world's nuclear plants would normally produce 2 billion metric tons
of CO2 per year if they depended on fossil fuels." In fact, nuclear fission produces around a
million times more energy (per unit weight) than fossil fuel alternatives. On the other hand,
taking into account the geographical features of the country, nuclear power could be deemed
unsuitable in New Zealand. New Zealand is a small, mountainous country with a large
coastline. Similar to Japan, New Zealand is also prone to earthquakes as the country lies at the
point where two tectonic plates meet. Thus, if New Zealand was to build a nuclear power plant, an
earthquake of a large magnitude could easily damage the structure and a catastrophe much like
Fukushima would occur. Should New Zealand find itself in nuclear fall-out, it would not be
unexpected for the radiation released to drift across the country, covering the nation in a cloud of
radiation due to its size. Also, due to the relative size of if New Zealand coastline, it would not be
surprising for the radiation to wind up in the ocean, killing wildlife and spreading radioactive
pollution via ocean currents. New Zealand is a particularly isolate country and, in the event of
a nuclear disaster, it would be difficult for aid to reach. Based on the knowledge I have
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
gathered in this report, I feel that nuclear power, despite its many good qualities, is not worth
the risk. It is my personal belief that New Zealand should remain a Nuclear Free Zone. Looking
at the facts about nuclear energy and the dangers associated with it, coupled with New Zealand's
current economical and geological state, it would be unwise for New Zealand to use nuclear
energy to create electricity.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: Low Merit
3.
For Merit, the student needs to use physics knowledge to develop an informed
and reasoned response to a socio-scientific issue.
This involves:
•
•
explaining how or why the key physics ideas relate to the socio-scientific
issue
justifying the personal response using relevant physics knowledge to
explain why the position and the action(s) have been chosen.
The student has explained how fission reactions are used to generate nuclear
power (1), and justified their personal response in terms of the large amount of
energy produced by nuclear power being in excess of New Zealand’s
requirements (2).
For a more secure Merit, the student could:
•
•
© NZQA 2015
relate the key phwysics ideas to the issue more clearly by explaining what
nuclear waste is and how it is produced, and/or explaining what a nuclear
meltdown is and its repercussions
justify the personal response better by providing quantitative data on the
amount of energy produced per gram of fuel for different fuels and/or that
produced by renewable energy resources.
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Nuclear energy process
Nuclear reactions can occur two different ways. Nuclear fusion is the fusing of two atoms
nuclei to produce a heavier atom. Nuclear fission on the other hand is splitting of atoms
nuclei, creating energy which can be harnessed in a nuclear power plant. When fission
occurs, the atoms used (Uranium, Thorium, Plutonium etc) are bombarded with other
neutrons, releasing energy and free neutrons. These neutrons collide with other neutrons
causing a chain reaction, continuing the fission process. The chain reaction must be kept
under control. This is done by rods of nuclear fuel in the reactor core. These rods are made
up of pellets of Zirconium which allows the free neutrons to be absorbed and pass through
between the pellets. These rods are inserted/removed from the core as needed.
Fission of uranium atoms inside the reactor core starts the energy production process. The
core contains several nuclear fuel assemblies, each of which contains several hundred
sealed tubes. Each tube in turn contains pellets of with a rich proportion of Uranium-235.
The Uranium-235 nucleus collides with a neutron splitting the nucleus into two fragments,
and in the process ejecting 2 or 3 neutrons. These neutrons are then able to collide with and
split other nuclei maintaining a chain reaction. The on-going chain reaction, and energy
released from collisions causes a high level of heat within the fuel tubes. The energy
released in a nuclear fission reaction boils water into steam. This in turn pushed
turbines to create electricity. The walls of the nuclear reactor are built from concrete and
steel to stop a reaction form going into the environment, especially in the case of a
meltdown. As a product of the nuclear fission process, the splitting of Uranium atoms creates
smaller radioactive isotopes such as cesium-137, stronium-90. These are known as 'fission
products'. These isotopes have radiation that is highly penetrating.
Strontium-90 has a half-life of 30 years, meaning in 30 years half its radioactivity will have
decayed. Different radioactive isotopes have different length half-lives, all the while they are
emitting harmful radiation. Radioactive waste such as fission products must be disposed of
in a safe way or else it could cause massive destruction to the environment.
In my opinion, I do not think nuclear power plants are needed in New Zealand. Our energy
demand is not very high and nuclear plants generate huge amounts of energy. Our clean
green image is also too valuable to us and bringing nuclear power to our country only brings
the risk of destroying this. I do not think this is worth risking for more power because our
sources of power are enough for NZ and they are economical and safe. In the future, I do not
think NZ should look at nuclear power, even as the population increases, because we have
so much room to build more windmills and solar stations which are economical and safe for
our environment.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: High Achieved
4.
For Achieved, the student needs to use physics knowledge to develop an
informed response to a socio-scientific issue.
This involves:
•
•
explaining the key physics ideas relating to the socio-scientific issue
presenting a personal response and proposing action(s) at a personal and/
or societal level, using relevant physics knowledge.
The student has explained how nuclear energy is generated (1), and expressed a
personal position by referring to the large amount of energy per kilogram produced
by nuclear power stations (2).
To reach Merit, the student could:
•
•
© NZQA 2015
relate the physics ideas to the issue by explaining why nuclear waste is
radioactive and the dangers associated with exposure to it
analyse, in more detail, the range of issues associated with the generation
of nuclear power, in order to justify the personal response.
Exemplar for internal assessment resource Physics for Achievement Standard 91527
A nuclear power plant uses controlled nuclear fission and heat produced by a nuclear fission
reaction uses Uranium-235 as fuel. The heat is used to boil water; the steam from the boiling
water turns a turbine which then generates electricity. A nuclear power plant uses much less
fuel than a fossil fuel plant (works same as nuclear plant, except uses oil or coal as fuel). "It
takes 1700 kilograms of coal to produce the same amount of electricity as 1 kilogram of
nuclear uranium fuel". This gives a huge advantage for nuclear plants as energy can be
produced much faster, though New Zealand, unlike Japan, is a small country and our energy
demands aren’t that high.
Based on the following report it would be considered ideal for many purposes to continue the
use of nuclear power plants within this country. Nuclear energy as outlined is a very viable
source of energy for this day and age, making it cost worthy, reliable and most of all efficient.
Nuclear energy provides over 11% of the world's electricity and is becoming more and more
popular due to its advantages. The physics of fission as a process of creating electricity is a
reliable process when contained and carried out safely. Although there have been
catastrophic incidents caused by nuclear power plants, it is of low risk that it will happen
again. Nuclear energy itself is advancing each day and safer ways of producing energy
within reactors is tightening. It would be in our best interest as a country with a large
population to use nuclear energy as our primary source.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: Low Achieved
5.
For Achieved, the student needs to use physics knowledge to develop an
informed response to a socio-scientific issue.
This involves:
•
•
explaining the key physics ideas relating to the socio-scientific issue
presenting a personal response and proposing action(s) at a personal and/
or societal level, using relevant physics knowledge.
This student has briefly explained the process of fission leading to nuclear power
generation (1) and presented a personal response (2).
For a more secure Achieved, the student could:
•
•
© NZQA 2015
explain the physics ideas more clearly by using equations and/or diagrams
to illustrate the process of nuclear fission
present the personal position more convincingly by stating quantitatively
the amount of energy released per unit mass of uranium.
Exemplar for internal assessment resource Physics for Achievement Standard 91527
In a nuclear power there is a variety of elements and atoms that create nuclear power
such as francium 235. These elements are isotopes, mainly fission isotopes. Fission
isotopes are isotopes that are neutron bombardment meaning that it’s highly
flammable, toxic and dangerous due to the fact that it can potentially tear the nucleus
apart hence causing radiation to occur. The main element in nuclear power is Uranium.
Uranium is an extremely heavy metal, which can be used as a reliable or abundant
source of concentrated energy. The element uranium undergoes a slow radioactive
decay process like all radioactive elements or atoms, meaning they undergo a halflife. The term half-111e describes how long it takes for a radioactive material or
substance to decay. A Uranium atom and is also an isotope. An isotope is an element
with the same atomic number but different mass number in which uranium contains
two isotopes Uranium 23E1 and Uranium 235.Uranium 238 or U-238 decays like all
radioactive isotopes but slowly due to the fact that its half-life is the same age as the
earth (4500 million years), therefore uranium rarely becomes radioactive. Uranium only
gathers or generates 0.1 watts/tonne as it decays heat therefore also proving the fact
that uranium is a slow decaying isotope. Uranium 235 or U•235 can be split easily
under certain amount of conditions, therefore exposing high amounts of energy. As a
result uranium 235 is best described as a nuclear fission. Nuclear waste is 90%
uranium, meaning that also contains 90 % unstable fuel. This means that Its radiation Is
thus dangerous until living organisms, especially us humans due to the fact that
radioactive half-life of uranium is 4.46 billion years which is a huge problem in regards
to the protection of our people and the environment as its half will take generations and
generations to decay hence If a person, group or species enters its radius it will cause
serious injury and eventually death.
I believe that the reason why nuclear power is used, because scientist look at how it benefits
us. They believe that nuclear power is the most concentrated form of energy. It required
small mass or amount of fuel but can release and produced lot of energy. Scientists
believe that this contribute to the reducing of transport cost. This is really true, we all
need to safe money for transportations but on the other hand, they must look first at
how nuclear waste affect all living things in the future. This is the reason why
scientists tried their best to find the best way to store nuclear waste and how they will
do that. They have used many methods for storing nuclear waste. They used
underground, under sea caves and caverns and sometimes mountains.
© NZQA 2015
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Grade Boundary: High Not Achieved
6.
For Achieved, the student needs to use physics knowledge to develop an
informed response to a socio-scientific issue.
This involves:
•
•
explaining the key physics ideas relating to the socio-scientific issue
presenting a personal position and proposing action(s) at a personal and/
or societal level, using relevant physics knowledge.
This student has described how nuclear waste is related to the production of
nuclear power (1), and gathered evidence for and against nuclear power (2).
To reach Achieved, the student could:
•
•
© NZQA 2015
relate the physics of nuclear power generation to nuclear waste, i.e.
describe nuclear fission
present a personal position based on the evidence gathered.
Exemplar for internal assessment resource Physics for Achievement Standard 91527
Nuclear Waste what Is it?
Nuclear waste that is released from when splitting Uranium in a nuclear reactor will
produce waste that is highly radioactive which will last for thousands of years. Due to its
danger. nuclear reactors have safety precautions to maintain and dispose of its waste. The
waste is Incredibly toxic when Its being removed the control rods to be disposed. The
nuclear waste. will usually be kept in water for a few years until its radiation has decayed
enough to be properly handled and put underground.
Now is it disposed?
Nuclear waste is disposed by large concrete caskets which are then put underground.
However the reactors produce a lot of nuclear waste and the radiation from the waste Is
frowned upon by the public, as this is a hot topic where the waste should be disposed and
weather people want a nuclear reactor.
The Impact of Chemobvl?
The Chernobyl incident was a Nuclear reactor accident that occurred in 1988. was caused by
inexperienced personnel and human error. Workers who were assigned were not fully
trained and they could not effectively maintain the correct precautions. The area of
Chemobyl is uninhabitable due to the radiation that has affected the area. The impact of
Chernobyl were that officially 30 people died from the disaster however unofficially
thousands more have died from ongoing symptoms from the radiation.
Fukushima disaster?
The Fukushima disaster was not man made as it was caused by an earthquake that
triggered a tsunami that disabled the power supply and cooling system in place for the
nuclear reactor. Three cores where damaged and melted. The death toll from the tsunami
was over 19.000 which wreaked havoc on the nuclear reactor to cause more severe
damage. The coming weeks after were maintained on keeping the cores down to a heat
level that could be maintained. There were only 3 employees that were known to have
been killed by the damage from the tsunami however no deaths from the reactor are
known.
All in all nuclear energy is a safe and effective way of creating large amounts of energy
efficiently and safely. The initial cost of setting up a reactor is big but once up at running Nuclear
energy is very cost effective at producing clean energy, the expected fuel reserves left are around
800years so nuclear energy is likely to stick around a bit longer.
© NZQA 2015