Interaction of Radiation:

As reactor coolant water passes by the core region of an operating reactor that is exposed to intense radiation. The main elements of the radiation field are neutrons, gamma rays, protons, and high energy electrons (beta particles). These categories of radiation interact along with the coolant water primarily through an ionization procedure and have a marked effect on the water itself and on the chemical reactions among substances dissolved within the water.  This section elaborates these effects, and in exacting the effects which include gases dissolved in reactor coolant.

The interaction of radiation along with matter generates ion pairs.  Commonly, the negative member of the ion pair is a free electron and the positive member is a polyatomic cation, an exact nature of that depends on the particular substance being irradiated.  For instance, the interaction of radiation along with water is described through the following reaction.

H₂O + radiation →   e^- + H₂O+

Both of these species are extremely reactive chemically, and there are various reaction pathways available to every. A few of these mechanisms are extremely complex and are commonly of little practical value to the reactor operator, who is more concerned along with the whole, observable effects.  In that case of water, the whole effect of irradiation is displays in the following reaction.

2H₂O  + radiation    → 2H₂ + O₂

Since this output is not at all apparent from Reaction (3-1), the subsequent section defines the intermediate processes in a few details.  This discussion is presented just to describe the category of reaction mechanisms which occur in irradiated solutions. Following discussions primarily include only the whole effects of these processes.