MCNP Secondaries (PWR Coolant activation)

[Kashif]

I have to calculate the gammas produce due to oxygen activation in the coolant of PWR reactor core. the tally i used is F4 and FM.. but the problem is in core their are different cells within a cell. so how to specify the required cell . i have selected the whole core as a cell and then specify oxygen as a material in FM card with the reaction number 102 for(neutron, gamma) reaction. and then i multiply the result with source strength in core. but the results are 100 times more than actual ...
Please help me in this regard.

 

[Aaron Barnard]

To accurately simulate the gamma production due to oxygen activation in the coolant of a PWR reactor core, you need to use a 3-dimensional model that accounts for the different cells within the core. You should also consider the neutron spectrum, cross-sections, and other parameters that affect the gamma production. Additionally, it is important to know the specific materials present in the core, their concentrations, and the reaction rates for oxygen activation. Without this information, it is not possible to accurately predict the gamma production.

 

[raining Pete]

First of all, it's great that you are working on calculating the gammas produced due to oxygen activation in a PWR reactor core. This is a complex task, so it's understandable that you are facing some challenges.

One thing to keep in mind is that the results you get from your calculations may not always match the actual values exactly. There could be various factors that contribute to this discrepancy, such as variations in the material properties, modeling assumptions, or even errors in your calculations. So, while it's important to try and get as close to the actual values as possible, it's also important to keep in mind that there may be some margin of error.

In terms of specifying the required cell, it's important to carefully select the cells that are relevant to the oxygen activation process. You mentioned that there are different cells within a cell in the core, so it's important to identify which cells are actually involved in the process and only include those in your calculations. Including unnecessary cells can lead to inaccurate results.

Additionally, it's important to make sure that the material and reaction numbers you are using are correct. Double check your input to ensure that you have specified the correct material and reaction numbers for oxygen activation.

Lastly, it may also be helpful to consult with other experts or do some research to see if there are any specific guidelines or best practices for calculating gammas produced due to oxygen activation in a PWR reactor core. This could provide some insights or tips that could help you improve your calculations.

I hope this helps and good luck with your calculations!