Question

Explain three ways in which the composition of fuel changes while it is in an operating reactor, and how each change affects reactor operation.   You may discuss nuclear, chemical, or material changes, or a combination.

Answer 1

first we will discuss nuclear changes & how they affect reactor operation

in nuclear reactor fuel is consume during fission

fuel is changing composition during irradiation

neutrons are consume & created during fission,neutraons has to sustain a fission chain reaction

Reactor design must consider neutonic thermal mechanical chemical properties .change in one property may affect other.

Chemical changes that affect the composition of fuel

chemical changes results in change of composition of fuel .In petroleum refinaries the crude oil undergoes various chemical operations that changes there compostion , long chain carbon are break down in smaller or more valueable products .some operations like cracking reforming pyrolysis is done to serve this purpose.

While fuel is in operting reactor combustion takes place and fuel convert into carbon dioxides ,carbon monoxide & water vapour .this affects reactor operations .it can affect the efficiency of fuel .

Material changes

while fuel is undergoing reaction in reactor it undergoes some chemical ,thermal & physical changes.as we know every material has unique properties replacing one material by other can not serve in same way . It may serve same purpose but reactor design will change accordingly . Not only disign but operating conditions as well.you can take example of gasoline & diesel to make it clear.