1.
To fission more of a given amount of fissile materials, boosted weapons
Correct Answer
B. ...receive a small amount of material that can undergo fusion (deuterium and tritium) that is placed inside the core of the fission device
Explanation
Boosted weapons receive a small amount of material that can undergo fusion (deuterium and tritium) that is placed inside the core of the fission device. This fusion process allows the weapon to release large numbers of neutrons, which in turn increases the efficiency of fission and allows for a greater amount of fissile material to undergo fission.
2.
Newer designs for nuclear power plants
Correct Answer
C. ...are much simpler and have built-in passive safety measures
Explanation
Newer designs for nuclear power plants are much simpler and have built-in passive safety measures. This means that these designs are less complicated compared to older designs. The inclusion of passive safety measures indicates that these newer designs have safety features that do not require human intervention or external power sources to function properly. This advancement in design aims to enhance the safety and reliability of nuclear power plants.
3.
Centrifuge Enrichment.
Correct Answer
C. ...exploits the mass difference between U-235 and U-238
Explanation
The given answer explains that centrifuge enrichment exploits the mass difference between U-235 and U-238. This means that the process takes advantage of the fact that U-235 is lighter than U-238. By spinning the centrifuge, the lighter U-235 is forced to the top, where it can be separated and extracted. This process is highly accessible to both state and non-state actors, making it a concern for nuclear proliferation.
4.
Why is uranium enrichment key for nuclear weapons production?
Correct Answer
B. To increase the percentage of Uranium 235, a fissionable material, in a given mass of uranium
Explanation
Uranium enrichment is key for nuclear weapons production because it allows for the increase in the percentage of Uranium 235, which is a fissionable material, in a given mass of uranium. This is important because Uranium 235 is the isotope that can sustain a chain reaction in a nuclear reactor or bomb. By increasing the percentage of Uranium 235 through enrichment, the uranium becomes more suitable for use in nuclear weapons.
5.
Reprocessing spent nuclear fuel is...
Correct Answer
B. ...a hotly debated topic with respect to the future of nuclear energy
Explanation
The given correct answer suggests that reprocessing spent nuclear fuel is a hotly debated topic with respect to the future of nuclear energy. This implies that there are differing opinions and discussions surrounding the practice of reprocessing spent nuclear fuel, and its role in shaping the future of nuclear energy.
6.
Fissile Materials are:
Correct Answer
A. Materials whose nuclei can break apart when bombarded with neutrons, emitting more neutrons than they absorb
Explanation
Fissile materials are substances that have the ability to undergo nuclear fission when bombarded with neutrons. During this process, the nuclei of these materials break apart, releasing a large amount of energy and additional neutrons. These emitted neutrons can then go on to bombard other fissile nuclei, causing a chain reaction and releasing even more energy. This characteristic of fissile materials makes them valuable for use in nuclear reactors and weapons, as they can sustain a self-sustaining nuclear reaction.
7.
A gun-type nuclear weapon…
Correct Answer
A. …fires two sub critical masses into one another to form one supercritical mass
Explanation
A gun-type nuclear weapon works by firing two subcritical masses into one another to form one supercritical mass. This causes a nuclear explosion. This design was used in the first atomic bombs, such as the "Little Boy" bomb dropped on Hiroshima in 1945. The gun-type design is relatively simple and relies on the principle of bringing two subcritical masses together to create a critical mass and initiate a chain reaction.
8.
Thermonuclear weapons...
Correct Answer
C. ...use a fission trigger to set off a separate stage of fusion
Explanation
Thermonuclear weapons use a fission trigger to set off a separate stage of fusion. This means that the weapon utilizes the energy released from a fission reaction to initiate a fusion reaction, resulting in a much more powerful explosion. By combining the two processes, thermonuclear weapons are able to achieve a significantly higher yield compared to purely fission-based weapons. The fission trigger acts as the catalyst for the fusion reaction, creating a chain reaction that releases an immense amount of energy.
9.
Which of the following countries are known or widely believed to have produced nuclear weapons?
Correct Answer
C. Russia, South Africa, North Korea, China
Explanation
The countries known or widely believed to have produced nuclear weapons are Russia, South Africa, North Korea, and China. These countries have either openly acknowledged their possession of nuclear weapons or are suspected to have developed them based on intelligence reports and international assessments. The United States, France, Israel, United Kingdom, Pakistan, and India are also known to possess nuclear weapons, but they are not mentioned in the given options. Sweden, Switzerland, and Argentina are not typically associated with nuclear weapons production.
10.
Which of the following does the IAEA consider significant quantities required to produce a nuclear weapon?
Correct Answer
C. 25 kg of HEU and 8 kg of Plutonium
Explanation
The IAEA considers 25 kg of HEU (Highly Enriched Uranium) and 8 kg of Plutonium as significant quantities required to produce a nuclear weapon. These specific amounts of fissile materials are considered significant because they provide enough fuel for a sustained nuclear chain reaction, which is necessary for the detonation of a nuclear bomb. By setting these thresholds, the IAEA aims to monitor and prevent the illicit production and proliferation of nuclear weapons.
11.
The atom is:
Correct Answer
C. The basic building bloc of all material
Explanation
The correct answer is "The basic building bloc of all material." This answer is supported by the fact that atoms are the fundamental units of matter. They combine to form molecules, which in turn make up all the materials and substances around us. Atoms are composed of protons, neutrons, and electrons, and their different arrangements and interactions give rise to the vast diversity of materials in the universe. Therefore, atoms can be considered as the building blocks from which all matter is constructed.
12.
The minimum amount of material necessary to sustain a chain reaction is called:
Correct Answer
B. A critical mass
Explanation
A critical mass is the minimum amount of material required to sustain a chain reaction. This means that if the amount of material is below the critical mass, the chain reaction will not occur. The term "nuclear mass" is not accurate in this context because it does not specifically refer to the minimum amount needed for a chain reaction. Similarly, a "sub-critical mass" implies a mass that is below the critical mass and therefore cannot sustain a chain reaction.
13.
For a nuclear reactor with an output of 1000 megawatts (MWe), the core would contain about:
Correct Answer
A. 75 tons of low-enriched uranium
Explanation
The correct answer is 75 tons of low-enriched uranium. This is because low-enriched uranium is commonly used as fuel in nuclear reactors. The amount of uranium required depends on the power output of the reactor. In this case, a reactor with an output of 1000 megawatts would typically contain around 75 tons of low-enriched uranium. This amount is sufficient to sustain the nuclear reaction and generate the desired level of power.
14.
Which two elements can be used to develop a nuclear weapon?
Correct Answer
C. Plutonium and Uranium
Explanation
Plutonium and Uranium can be used to develop a nuclear weapon. Both elements are fissile materials, meaning they can sustain a chain reaction of nuclear fission. Plutonium-239 and Uranium-235 are the most commonly used isotopes for this purpose. Plutonium can be produced by irradiating Uranium-238 in a nuclear reactor, making it a valuable resource for nuclear weapons. The combination of Plutonium and Uranium allows for the creation of a critical mass, initiating a nuclear explosion.
15.
Which of the following answers is the most accurate? Producing plutonium...
Correct Answer
A. ...requires the construction of large and relatively visible facilities
Explanation
The correct answer is "requires the construction of large and relatively visible facilities." This answer is the most accurate because producing plutonium requires the establishment of specialized facilities that are large in size and can be easily noticed due to the nature of the process. Plutonium production involves complex and highly regulated procedures that necessitate the construction of dedicated facilities with specific equipment and infrastructure. These facilities are often closely monitored and subject to international scrutiny due to the potential risks associated with plutonium production.
16.
From a safeguards perspective, which are the most sensitive components of the nuclear fuel cycle?
Correct Answer
A. Enrichment and Reprocessing
Explanation
Enrichment and reprocessing are the most sensitive components of the nuclear fuel cycle from a safeguards perspective. Enrichment involves increasing the concentration of uranium-235 in nuclear fuel, which is necessary for the production of nuclear energy or weapons. Reprocessing refers to the separation of plutonium and uranium from spent nuclear fuel, which can also be used for nuclear weapons. These processes require strict controls and monitoring to prevent the proliferation of nuclear weapons and ensure the safe and secure use of nuclear energy.
17.
Gaseous Diffusion relies on the fact that:
Correct Answer
A. Heavier gas travels faster than lighter gas
Explanation
Gaseous diffusion relies on the fact that heavier gas travels faster than lighter gas. This is because the process involves passing a mixture of gases through a porous barrier. The lighter gas molecules are able to pass through the barrier more easily, while the heavier gas molecules move more slowly. This difference in speed allows for the separation of gases based on their molecular weight, with the lighter gas collecting on one side of the barrier and the heavier gas on the other side.
18.
The implosion nuclear weapons design was tested for the first time:
Correct Answer
B. By the US at Alamogordo, New Mexico, in July 1945
Explanation
The implosion nuclear weapons design was tested for the first time by the US at Alamogordo, New Mexico, in July 1945. This was the first successful test of an implosion-type nuclear weapon, known as the Trinity test. It marked a significant milestone in the development of nuclear weapons technology and paved the way for the use of such weapons during World War II. The test demonstrated the feasibility and destructive power of implosion designs, which involve compressing a subcritical mass of fissile material to achieve a supercritical state and initiate a nuclear chain reaction.
19.
Which of the following nuclear weapon is, relatively speaking, easier to manufacture?
Correct Answer
A. Gun-type device
Explanation
The gun-type device is relatively easier to manufacture compared to the hydrogen device and implosion device. In a gun-type device, two sub-critical masses of fissile material are brought together by firing one piece into another, creating a supercritical mass and initiating a chain reaction. This design is simpler and requires less precision engineering compared to the other two options. The hydrogen device, also known as a thermonuclear bomb, involves a more complex process of combining nuclear fusion and fission reactions. The implosion device also requires precise timing and shaping of conventional explosives to compress a sub-critical mass into a supercritical one.
20.
Used fuel assemblies taken from the reactor core are:
Correct Answer
A. Highly radioactive and give off a lot of heat
Explanation
Used fuel assemblies taken from the reactor core are highly radioactive because they contain radioactive isotopes that have undergone fission reactions in the reactor. These isotopes emit radiation, which makes the fuel assemblies highly radioactive. Additionally, the fission reactions produce a significant amount of heat, so the fuel assemblies also give off a lot of heat. This high level of radioactivity and heat makes handling and storing used fuel assemblies a challenging and potentially dangerous task.