on immediately. B1\n- Fusion does not involve or produce weapons-grade materials (such as enriched uranium or plutonium), greatly reducing security risks and radiation safety threats associated with nuclear proliferation. B1\n- The operational radioactive waste produced in fusion consists mainly of short-lived activated structural materials, which decay to safe levels within decades rather than millennia. B1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"select_two_safety_advantages","label":"Choose two safety advantages","steps":[{"type":"text","order":0,"title":"Read the comparison","content":"The question asks for **two distinct advantages** of fusion **rather than** fission, and restricts the focus to radiation safety or radioactive-waste management. Give two separate comparison points, not two versions of the same idea.","highlights":[{"text":"two distinct advantages, regarding radiation safety or radioactive waste management","location":"specification"},{"text":"nuclear fusion reactor to generate electricity rather than a conventional nuclear fission reactor","location":"specification"}]},{"type":"text","order":1,"title":"Explain the waste advantage","content":"First, use radioactive waste management. Fusion does **not** produce the high-level, extremely long-lived waste made by fission, such as spent fuel containing fission products and actinides. Therefore, it does not need storage in a deep geological repository for hundreds of thousands of years.\n\nThis is one clear, developed advantage and earns **B1**."},{"type":"text","order":2,"title":"Give a separate advantage","content":"For the second mark, choose a different safety point: fusion cannot undergo a runaway chain reaction or catastrophic meltdown. If confinement fails, the plasma cools quickly, so the fusion reaction stops immediately.\n\nThis is distinct from the waste point, so it earns the second **B1**."}]}],"generatedAt":"2026-07-22T12:07:46.383Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"b41974e7-3cf3-4931-83e7-22af5ff73a76","revisionId":"7a6c70c7-4f06-4f70-a60f-759062cbb16d","questionNumber":null,"questionType":"LA","specification":"In a commercial nuclear fission reactor, uranium-235 nuclei undergo fission to release energy. During a specific operating interval, the total nuclear energy released by these fission reactions is $1.35 \\times 10^{11} \\text{ J}$.\n\nThis energy, $E$, is produced by the conversion of a small amount of mass, $\\Delta m$, according to the mass-energy equivalence equation:\n\n\\[E = \\Delta m c^2\\]\n\nwhere $c$ represents the speed of light, $3.0 \\times 10^8 \\text{ m/s}$.","difficulty":5,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"885ed452-0ec2-4e37-b327-d6245301cd89","label":null,"content":"Calculate the mass defect (the decrease in mass), $\\Delta m$, that corresponds to this energy release. Show your working.","markscheme":"- Rearranges the equation to make $\\Delta m$ the subject, $\\Delta m = \\frac{E}{c^2}$, or substitutes the values directly into the formula M1\n- Evaluates the denominator $c^2$ as $9.0 \\times 10^{16}$ A1\n- Obtains the final mass decrease of $1.5 \\times 10^{-6} \\text{ kg}$ (or equivalent, e.g. $1.5 \\text{ mg}$) with correct units A1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"mass_energy_rearrangement","label":"Rearrange and substitute","steps":[{"type":"hyper_latex","block":{"nodes":[{"latex":"E=\\Delta m c^2"},{"latex":"\\Delta m=\\frac{E}{c^2}"}]},"order":1,"title":"Rearrange the equation","description":"Make the mass defect the subject before putting in the numbers. This earns the method mark, even if a later arithmetic step goes wrong."},{"type":"hyper_latex","block":{"nodes":[{"latex":"\\Delta m=\\frac{1.35\\times10^{11}}{\\left(3.0\\times10^8\\right)^2}"},{"latex":"\\left(3.0\\

Radiation safety and nuclear energy

Question 23

Radiation safety and nuclear energy Questions

Radiation safety and nuclear energy

Question 23

Radiation safety and nuclear energy Questions