Search found 381 matches

by Ville Valtavirta
Thu Feb 20, 2020 12:37 pm
Forum: Gamma transport
Topic: No photons detected when ngamma = 2
Replies: 2
Views: 137

Re: No photons detected when ngamma = 2

Hi, the weight limits for implicit photon production are not correctly set in 2.1.31. To fix this you will need to add the lines /* Implicit photon production */ WDB[DATA_PHOTON_IMPL_WMIN] = 0.1; WDB[DATA_PHOTON_IMPL_NMAX] = 10.0; to the end of initdata.c. This bug will be fixed in future updates. -...
by Ville Valtavirta
Thu Feb 20, 2020 11:23 am
Forum: Users
Topic: Negative volumes?
Replies: 1
Views: 97

Re: Negative volumes?

Hi,

which version of Serpent are you using? I don't think that is an error message that is present in the recent versions. (There isn't even a ProcessGeometry subroutine.)

-Ville
by Ville Valtavirta
Mon Feb 17, 2020 11:05 am
Forum: Users
Topic: what i must write in input file to calculate the particular reaction reate for U-235 in the fuel?
Replies: 6
Views: 267

Re: what i must write in input file to calculate the particular reaction reate for U-235 in the fuel?

Hi,

U-235 fission rate is already one of the default outputs found in the [input]_res.m file.

-Ville
by Ville Valtavirta
Mon Feb 17, 2020 11:02 am
Forum: Users
Topic: Going from the tutorial example to a 3D molten salt tank in 2 days.
Replies: 1
Views: 112

Re: Going from the tutorial example to a 3D molten salt tank in 2 days.

I imagine that depends on what kind of detail you need for your model and what kind of understanding you want to have regarding your model. There is a very simple molten salt tank input on the wiki already so that might be of help.

Edit: I see you already found that page.

-Ville
by Ville Valtavirta
Fri Feb 14, 2020 11:49 am
Forum: Users
Topic: Fatal Error: Insufficient Buffer size
Replies: 7
Views: 360

Re: Fatal Error: Insufficient Buffer size

Hi, a couple of things. Try adjusting your "set nps" card. Currently set nps 10000 100 simutime gives you 10000 neutrons in total, divided into 100 batches i.e. 100 neutrons per batch. I would suggest having at least 10000 neutrons per batch to decrease the batch-to-batch variance: set nps 10000 1 s...
by Ville Valtavirta
Fri Feb 14, 2020 11:37 am
Forum: Bugs, problems, questions & feeback
Topic: Issue with group constant fluxes with batching
Replies: 1
Views: 129

Re: Issue with group constant fluxes with batching

Hmm,

I noticed something similar recently. I imagine it has something to do with how the normalization is calculated. I'll have a look at this.

-Ville
by Ville Valtavirta
Thu Feb 06, 2020 6:34 pm
Forum: Users
Topic: Statistical errors Beta Sensitivity
Replies: 1
Views: 180

Re: Statistical errors Beta Sensitivity

Hi Heddy, this looks pretty interesting and it seems to be somehow related to the batching interval that is used. See http://serpent.vtt.fi/mediawiki/index.php/Input_syntax_manual#set_pop : %Jezebel - Bare sphere of Pu-239 with 4.5% Pu-240 CSEWG-F1 and PU-MET-FAST-001 set title "jezbel_pu39" set pop...
by Ville Valtavirta
Thu Feb 06, 2020 5:30 pm
Forum: Users
Topic: Sensitivity Analysis Issues
Replies: 6
Views: 432

Re: Sensitivity Analysis Issues

Hi Heddy, it seems the simulations did give some results. I tried calculating the void reactivity coefficient sensitivity to U-235 total nubar, which is Fig. 9 in this article . The shape does seem to agree pretty well: Void_sens_1_1_2.png The evaluation of void reactivity coefficients seems to be s...
by Ville Valtavirta
Thu Feb 06, 2020 5:18 pm
Forum: Users
Topic: Reactor Tutorial Case (part 5). Infinite surface not allowed in universe 0.
Replies: 2
Views: 156

Re: Reactor Tutorial Case (part 5). Infinite surface not allowed in universe 0.

The tutorial is now updated. Let me know if something does not work.

-Ville