Search found 74 matches

by Antti Rintala
Tue Jan 26, 2021 10:57 am
Forum: Users
Topic: Unrealistic DF values with 2.1.31
Replies: 8
Views: 760

Re: Unrealistic DF values with 2.1.31

The outer boundary depends on what you are trying to simulate. Are you trying to simulate an infinite lattice of such 7 assembly configurations? Then if you have for example x-type hexagonal assemblies, then you can have a x-type hexagonal outer boundary cutting those 6 surrounding assemblies in hal...
by Antti Rintala
Mon Jan 25, 2021 8:44 am
Forum: Users
Topic: Unrealistic DF values with 2.1.31
Replies: 8
Views: 760

Re: Unrealistic DF values with 2.1.31

Is this an input you could post here?

Do you calculate with two ore more energy groups? The overlapping surfaces shouldn't generally be a problem here, but what was your problem with a lattice? A model with seven hexagonal fuel assemblies should be easy and straightforward to build using a lattice.
by Antti Rintala
Fri Jan 15, 2021 9:45 am
Forum: Users
Topic: Poisons XS generation
Replies: 5
Views: 559

Re: Poisons XS generation

The volumes for the fissionable zones have to be correct for these results to be correct. The volume ratio is optional but the results might not be what you expect them to be if you don't define it. If I remember correctly, this topic is related to this matter: https://ttuki.vtt.fi/serpent/viewtopic...
by Antti Rintala
Fri Jan 15, 2021 9:28 am
Forum: Users
Topic: Question about 1/8 lattice Pin-power form factors?
Replies: 2
Views: 428

Re: Question about 1/8 lattice Pin-power form factors?

I'd say you still have problems with your post processing, as it is a non-trivial thing to do. Things that have to be taken into account is that for a 17x17 lattice and 1/8 symmetry are that middle pin receives only 1/8 of the power, and the pins on the boundaries of the 1/8 symmetry section only re...
by Antti Rintala
Wed Jan 13, 2021 9:36 am
Forum: Users
Topic: Poisons XS generation
Replies: 5
Views: 559

Re: Poisons XS generation

The microscopic absorption cross sections for poisons are calculated with Eq. (7) of https://doi.org/10.1016/j.anucene.2016.06.007 in the most recent versions. Note that this equation does not take the distribution of the poison nuclides within the homogenization volume correctly into account. See f...
by Antti Rintala
Fri Jan 08, 2021 8:28 am
Forum: Users
Topic: Group normalized flux values
Replies: 6
Views: 680

Re: Group normalized flux values

The INF_FLX results are normalized to whichever normalization (set power, set powdens, set flux, set genrate, set fissrate, set absrate, set lossrate, set srcrate, set sfrate) you are using. I don't really remember to which value the B1_FLX values are normalized to, but their ratios are of course th...
by Antti Rintala
Tue Jan 05, 2021 8:59 am
Forum: Users
Topic: Serpent wiki page is not working
Replies: 1
Views: 263

Re: Serpent wiki page is not working

There has been some problems with the wiki. It also seems to work at the moment.
by Antti Rintala
Mon Jan 04, 2021 10:52 am
Forum: Users
Topic: Fatal error in function Mem
Replies: 1
Views: 333

Re: Fatal error in function Mem

Most probably you are running out of memory. You can try increasing the value in set memfrac (http://serpent.vtt.fi/mediawiki/index.p ... et_memfrac) or run the problem with a computer with having more memory available.
by Antti Rintala
Wed Dec 16, 2020 3:16 pm
Forum: Users
Topic: Error associated with MDENS and ADENS.
Replies: 3
Views: 454

Re: Error associated with MDENS and ADENS.

Depletion is always performed only with the best estimate values, so there is no statistical error information available.
by Antti Rintala
Wed Dec 16, 2020 2:06 pm
Forum: Users
Topic: Error associated with MDENS and ADENS.
Replies: 3
Views: 454

Re: Error associated with MDENS and ADENS.

Depends a lot on what you mean with the error. The values are obtained during depletion calculations, and are rather exact, given the initial compositions and the transmutation cross sections. Of course the cross sections are not exact. The statistical error caused by the Monte Carlo method can be e...