Update 1.1.18

[Jaakko Leppänen]

Update 1.1.18 is now complete and it was distributed to registered users by e-mail on August 18, 2012. Contact me if you didn't receive your copy. The major bug fixes and a few new features are listed in:

http://montecarlo.vtt.fi/updates/update1.1.18.htm

[Levon]

Hi Everybody

As you probably know Serpent's default output file "_res.m" contains almost all the group constants necessary for performing steady state calculations with PARCS 3D deterministic reactor core simulator.
The only missing parameter is the so called "kappa-fission" macro XS.
here "kappa" is "energy release per fission" and the unit in PARCS is [J/fission]
and "kappa-fission" is "kappa" times "fission macro XS".

As long as this parameter is not in the default output file, one needs to define a special detector as follows:

1. define energy grid. Here we are using ecco 33 group structure

Code: Select all

ene egrid 4 nj19

2. define detector to score "integral flux"

Code: Select all

det flux 
du 0 
de egrid

3. define detector to score "kappa fission" macro XS

Code: Select all

det kappafission
dr -8 void 
du 0 
dt 3 flux 
de egrid

My suggestion to Jaakko and Serpent developers is to add "kappa-fission" macro XS to the default output file "_res.m" in version 1.1.19 or at least from version 2.0.0 and on

One of the reasons is that it will essentially simplify the structure of the wrapper codes such as SerpentXS or S2P by removing the necessity to define detectors and analyze detector output files, which are dependent on detector names.
Furthermore, PARCS 3D reactor core simulator is "de facto" the major player among deterministic codes, approved by US NRC, used by almost everyone in nuclear and is default tool for coupling with TRACE code.
So let us respect "major players" and add the only missing "kappa-fission" for the sake of SERPENT-PARCS complete and "default" integration.

[Jaakko Leppänen]

Serpent calculates few-group constant called FISSE, which is the average energy deposited per fission in MeV. The product of FISSXS and FISSE should give the same result as your detector, right?

[Levon]

Yes, I just checked it and you are right, FISSE*FISSXS*(1.60219E-13) gives the same results as the above mentioned kappafission detector.
1MeV = 1.60219E-13 Joules.