Chapter 10 Multiple choice questions

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. Different types of nuclear radiation are described in Section 10.3. What is a beta particle?

Very short wavelength electromagnetic radiation correct incorrect

A helium nucleus correct incorrect

A high velocity electron correct incorrect

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. Section 10.3 also describes radioactive decay. Iodine 131 has a half-life of 8 days, i.e. the activity from a particular sample falls by a half in that number of days. How many days from the start will it take to reach 1/8th of its original activity?

16 days correct incorrect

24 days correct incorrect

32 days correct incorrect

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. Section 10.4 describes nuclear fission. When uranium 235 absorbs a fast neutron, it splits into two smaller atoms, fission products, such as krypton 89 and barium 144 and some surplus neutrons. Why are these neutrons so important?

They go on to produce more fission. correct incorrect

They are turned into protons. correct incorrect

They help convert the uranium into lead. correct incorrect

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. Box 10.6 describes moderators. What is the function of a moderator in a conventional fission reactor?

It holds the nuclear fuel. correct incorrect

It reduces the intensity of the nuclear reaction. correct incorrect

It slows down fast neutrons. correct incorrect

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. Section 10.4 also describes the breeding of plutonium 239 from uranium 238. What intermediate element is produced in this process?

Protactinium 234 correct incorrect

Americium 241 correct incorrect

Neptunium 239 correct incorrect

Thorium 234 correct incorrect

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. Section 10.6 describes different types of thermal fission reactors. Which type matches the following description: The reactor is cooled by carbon dioxide which is then pumped through a boiler to raise steam to drive turbines.

Pressurized water reactor correct incorrect

Advanced gas-cooled reactor correct incorrect

Boiling water reactor correct incorrect

CANDU reactor correct incorrect

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. Which type of reactor uses heavy water as a moderator and coolant?

Pressurized water reactor correct incorrect

Advanced gas-cooled reactor correct incorrect

Boiling water reactor correct incorrect

CANDU reactor correct incorrect

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. The nuclear fuel cycle is described in Section 10.7. Fission reactors require uranium 235. Why can't this simply be separated from uranium 238 chemically?

Uranium is completely chemically unreactive. correct incorrect

Uranium 235 and 238 are both the same chemical element. correct incorrect

Any chemical process would be far too dangerous. correct incorrect

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. What is the main constituent of spent fuel from a pressurized water reactor?

Plutonium correct incorrect

Uranium 238 correct incorrect

Fission products correct incorrect

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. Fast neutron reactors are described in Section 10.8. What is the key difference between these and conventional thermal fission reactors?

A fast neutron reactor can run on unenriched uranium. correct incorrect

A fast neutron reactor doesn't need a moderator but needs highly enriched fuel. correct incorrect

A fast neutron reactor needs an extra large moderator. correct incorrect