1. (20pts) Boron, Cadmium, Gadolinium and Hafnium are elements that are often used in control rods in nuclear reactors. Their cross-section for neutron absorption makes them attractive for this application.

Use the Chart of the Nuclides to compare the absorption cross-sections (thermal is listed first in barns) of these elements (not isotopes) with the fission cross-section of 235U. Rank them in order from smallest to largest.

1. (2 pts) An atom of Gold-198 contains how many neutrons?

1. (4 pts) Write the particle balance equation for Alpha decay of Radon-222.

1. (12pts) What nucleus results from each of the following radioactive decays:

1. (12pts) Balance the following nuclear reactions:

1. (50 pts) Compare and contrast a PWR with a high temperature gas reactor.  Include details such as fuel type, enrichment, and shape/size of bundles, moderator, coolant, neutron energy (fast or thermal), including how it works from the production of neutrons in the core to electricity entering the electrical grid.  What are the advantages or disadvantages of each design? ** [This will require you to research from outside sources and will require about a page to answer in detail]

** You must cite your sources for this assignment, and be careful to use reputable web resources. Format your references section according to a standard of your choosing (You may want to consider finding a citation editor, e.g. Mendeley, Zotero, Endnote, etc. and sticking with it throughout college)