Question

One important distinction between the Chornobyl reactors and those in the United States is that those in Chornobyl used graphite as a moderator to slow neutrons, whereas U.S. reactors use water. In terms of safety, give two reasons why water is a better choice.

Answer 1

Step-by-step explanation:

Both of the main reasons as to why water is used instead of graphite revolve around safety in case of an emergency. For starters, water is able to absorb a large amount of heat before actually getting hot. For water, its heat capacity is 4.186 joule/gram °C while Graphite is 0.720 joule/gram °C. Secondly, water does not ignite meaning it cannot catch fire, unlike Graphite which at a certain heat level it will begin to burn. This makes water far safer than graphite, especially in an emergency scenario such as a meltdown.