DYN_POP and DYN_PERIOD

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terryphi
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DYN_POP and DYN_PERIOD

Post by terryphi » Fri Oct 13, 2017 9:56 pm

Hi,

Any documentation on what DYN_POP and DYN_PERIOD are?

are these my neutron population and reactor periods?

I want to find reactor power as a function of time.

Ville Valtavirta
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Re: DYN_POP and DYN_PERIOD

Post by Ville Valtavirta » Mon Oct 16, 2017 1:10 pm

They should be neutron population (at the end of the time-interval) and the reactor period based on increase/decrease of neutron population during time interval.

For the reactor power, I would suggest using a detector using detector response -8 (macroscopic total fission energy production cross section). You can link a certain time-binning to your detector in order to get the results separately for different time-intervals: http://ttuki.vtt.fi/serpent/viewtopic.p ... 825&p=6000

You should note that the output quantity for "dr -8 void" will be energy deposition in Joules.

You should also read this section from the wiki: http://serpent.vtt.fi/mediawiki/index.p ... imulations

-Ville

trantuan
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Re: DYN_POP and DYN_PERIOD

Post by trantuan » Sun Nov 12, 2017 11:13 am

Hi,
In my case, I got the results from energy deposition (using detector response -8).
But I do not know how to calculate tallied results to get reactor power.
Can you help me?

Ville Valtavirta
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Re: DYN_POP and DYN_PERIOD

Post by Ville Valtavirta » Mon Nov 13, 2017 12:28 pm

Detector power is typically something you set yourself using "set power" (see http://serpent.vtt.fi/mediawiki/index.p ... #set_power).

What kind of a simulation are you running?

-Ville

trantuan
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Re: DYN_POP and DYN_PERIOD

Post by trantuan » Sun Nov 19, 2017 10:05 am

Ville Valtavirta wrote:Detector power is typically something you set yourself using "set power" (see http://serpent.vtt.fi/mediawiki/index.p ... #set_power).

What kind of a simulation are you running?

-Ville
hi,

I am running 3D BWR assembly transient example in Serpent page.
The results from that example is energy deposition (using detector response -8), but the results they shown on their paper are Power level, Then I do not understand how they can calculate Power level.
http://serpent.vtt.fi/mediawiki/images/ ... OR2016.pdf

Ville Valtavirta
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Re: DYN_POP and DYN_PERIOD

Post by Ville Valtavirta » Wed Nov 22, 2017 7:01 pm

The energy deposition is calculated in Joules, so if you calculate the energy deposition for your whole reactor using "dr -8 void" you will get the total energy deposition in your reactor during some time.

To get power from energy, you'll generally need to divide by time:

If you are defining a separate time-binning for your detector using "di <time_structure_name>", you can divide the value in each time bin (Joules) with the length of that time bin (seconds) to get the average power during that time (Joules/seconds = Watts).

If you don't define a time binning for your detector your results will be the total energy deposited during your simulation time (or during the previous time interval if you are running a coupled transient simulation) so you'll have to divide the detector output with the length of your simulation (or the length of the previous time interval for coupled transients).

The initial power level of the transient simulation should automatically correspond to the power level in the source generation simulation and can be scaled using "set transnorm" (http://serpent.vtt.fi/mediawiki/index.p ... _transnorm)

-Ville

trantuan
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Re: DYN_POP and DYN_PERIOD

Post by trantuan » Fri Nov 24, 2017 4:16 am

Hi,
I got it.

Thank you for your reply.

Tran Quoc Tuan

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