Search found 452 matches

by Ville Valtavirta
Wed Oct 13, 2021 3:56 pm
Forum: Users
Topic: Cumulative yield
Replies: 12
Views: 160

Re: Cumulative yield

Be sure to check the Serpent tutorial to learn about the basic Serpent use. For memory consumption see also set opti.

-Ville
by Ville Valtavirta
Fri Oct 01, 2021 12:39 pm
Forum: Users
Topic: Inconsistent particle XS values from detector between averaged tally and individual tally
Replies: 10
Views: 207

Re: Inconsistent particle XS values from detector between averaged tally and individual tally

When you averaged the capture cross sections across the particles in postprocessing, did you remember to use flux volume weighting for the homogenization? Homogenized cross sections cannot be averaged over larger regions through simple averaging.

-Ville
by Ville Valtavirta
Tue Sep 21, 2021 1:41 pm
Forum: Users
Topic: Pebbles motion
Replies: 13
Views: 854

Re: Pebbles motion

Hi,

I think uploading scripts to e.g. github and linking the page here should be OK.

-Ville
by Ville Valtavirta
Wed Sep 15, 2021 8:46 am
Forum: Users
Topic: Pebbles motion
Replies: 13
Views: 854

Re: Pebbles motion

Hi, could you explain why you do not want further decay for the discarded pebbles to help me understand what might be the best way to solve your problem? If you are writing restart files and _dep.m output files on a material-zone basis, you should already get the nuclide compositions of each pebble ...
by Ville Valtavirta
Wed Sep 01, 2021 12:41 pm
Forum: Users
Topic: Statistic uncertainty Keff for transients calculations
Replies: 3
Views: 223

Re: Statistic uncertainty Keff for transients calculations

Hi,

all of the result variables in <input>_res.m have their associated relative uncertainties printed out in the file. However, you will not get separate results from the different time-intervals in transient simulations.

-Ville
by Ville Valtavirta
Fri Aug 27, 2021 2:54 pm
Forum: Users
Topic: Decay heat - burnup step dependency
Replies: 5
Views: 251

Re: Decay heat - burnup step dependency

Hi Ondrej, the momentary decay heat estimation during full power operation has a significant component coming from very short lived nuclides, the concentrations of which are very sensitive to the potential time-discretization error in the depletion calculations. I would imagine that comparing decay ...
by Ville Valtavirta
Wed Aug 25, 2021 8:59 am
Forum: Users
Topic: general concepts
Replies: 19
Views: 708

Re: general concepts

To put it even more simply,

there is no specific power level that corresponds to some assembly that can be solved with neutronics. If the assembly is critical at the power level of, say 1 kW, it is critical at the power level of 1 MW too when only considering neutronics.

-Ville
by Ville Valtavirta
Tue Aug 24, 2021 9:07 am
Forum: Users
Topic: general concepts
Replies: 19
Views: 708

Re: general concepts

Hi, you have to set the normalization for the simulation yourself using one of the options in Serpent. See Serpent manual section "5.8 Source rate normalization". For pure neutronic calculations the choice of a power level in the system is arbitrary and, for that reason the normalization needs to be...
by Ville Valtavirta
Tue Jul 20, 2021 10:14 am
Forum: Users
Topic: Fission rate in transient simulations
Replies: 6
Views: 440

Re: Fission rate in transient simulations

Could you explain a bit more about the transient you want to model. What kind of conditions do you want to begin the transient from? What kind of initial distributions do you want to use for delayed neutron precursors? You cannot generate physical initial delayed neutron precursor distributions from...
by Ville Valtavirta
Thu Jul 15, 2021 4:36 pm
Forum: Users
Topic: Fission rate in transient simulations
Replies: 6
Views: 440

Re: Fission rate in transient simulations

Hi, it's probably better to use one of these approaches: http://serpent.vtt.fi/mediawiki/index.php/Dynamic_external_source_simulation_mode http://serpent.vtt.fi/mediawiki/index.php/Transient_simulations The first one if you do not need to concern yourself with the delayed neutron source and the seco...