SCALE 5 ORIGEN: ORIGEN and COUPLE

[SCALE Software Coordinator]

This topic has been migrated from the SCALE 5 ORIGEN notebook.

Date: Wed Aug 5 09:55:58 2009

Dear gentlemen,

I am a new user and I am trying to use origen-s to calculate the inventory in an hybrid fission-fusion machine (actualy I am working at ITER project). I am using the chain COUPLE-NITAWL-XSDRNPM-COUPLE-ORIGENS directly (i mean not using the sas2 routine). The data of my problem are: I used a spherical geometry, a neutron source of 14 Mev located in the center of the sphere (volumetric source with a radius of 1 cm), a thickness of 2 cm of U-238 placed at 850 cm from the center of the sphere. I need to collapse and weight the cross section in 3 group of energy, as requested from COUPLE. My first question is:

1) when i transform the origens library from a card library to a binary library , which kind of library i have to choose (i mean for which reactor, LWR, HTGR, LMFBR)? I suppose that in principle i could choose whatever library, because i will weight the cross section with the flux that i will found with XSDRNPM.

 

2) I noted that using a monoenergetic spectrum of 14 Mev the answer of origen on the irradiated life of U-238 is completely wrong. I suppose that the point is the fact that the cross section are normalized with the thermal flux which is almost zero. In fact i tried to put a sorce spectrum with a thermal component (i substitute the row 31** of XSDRNPM with the command 31** 3R0 1 220R0 .01 13R0 T) and it seems work.

 

I know that origens has been used also to do the inventory of the ADS systems where the source spectrum is harder.

What wrong ?... could You explain me.

Thanks in advance.

I will send you the input file.

Elio D'Agata

 

=COUPLE

- LIBRERIA (LMFBR) -

0$$ a2 28 a6 34 e

1$$ 1 1 a11 1010 e

2** a2 2 3 4 1t

5$$ 3 3t

35$$ 0 5t

0$$ a4 34 e

1$$ a5 1 a13 -1 e 1t

DONE

END

=NITAWL

0$$ 84 E

1$$ 2000 3 a8 1 E T

2$$ 1001 999 92238

3**

92238 500. 3.0 852.0 0.0 850.00 40.47e-3 1

238 10 1 238 10 0.0 1 T

4** F500 T

END

=XSDRN

Calcolo reattore ibrido

1$$ 3 3 30 1 0 3 4 8 3 0 40 20 0 0 0

3$$ 1 1 A9 4 E

4$$ 0 3 0 -1 E

5** 2R10.-5 1.1968e20 E T

13$$ 1 2 3 3

14$$ 1001 1001 999 92238

15** 1.e-20 1.e-20 1 40.47e-3 T

30$$ 1 29R0

31** 3R0 1 234R0 T

33## F0 T

35** 1I0.0 7I1.0 19I850 852

36$$ 2R1 8R2 20R3

39$$ 1 2 3

49$$ 92238 92238 92238 92238

50$$ 4 18 101 452

51$$ 23R1 180R2 35R3 T

END

=COUPLE

*** (LMFBR) case ***

*

(problem dependent neutron spectrum factors)

used 238 group scale library and converted.........

0$$ a4 34 a6 32 e

1$$ a12 922380 a16 3 1 1 1 e

2** 120 e t

0$$ a4 32 e

1$$ a2 1 a5 1 a13 -1 e t

DONE

END

=ORIGENS

1$$ 1 t

(LMFBR) BLANKET

3$$ 32 a3 1 a16 2 e

54$$ 5 e t

35$$ 0 t

56$$ 20 20 1 a6 1 a13 1 4 3 0 2 1 1 0

57** 0 0 1 e t

(LMFBR)

BLANKET TO BURN ACTINIDES

59** f2.216e13

60** 18i10 200

66$$ 2 a5 2 a9 2 e

73$$ 922380

74** 291.22e6

75$$ 2 t

56$$ f0 t

end

 

[SCALE Software Coordinator]

Dear Elio,  

The ORIGEN-S libraries (LWR, HTGR, etc) contain different fission product yields (thermal vs. fission energy) and cross section values. Although you are updating cross sections from your XSDRN transport cross sections, this update is only performed for nuclides in the transport library (~230), which is much fewer than available in ORIGEN-S. So ORIGEN-S will use the older cross sections for anything not updated. For fast neutron systems, I would select the LMFBR library which has fission-energy (fast) yields for all nuclides. This is still not quite correct since 14 MeV is considered high energy, but it is better than thermal yields. We are currently in the process of adding high-energy yields, but have not completed this work yet. Note that for LMFBR cross sections, the value of THERM, RES, and FAST in the COUPLE case should be set to 1.0, in which case the code will use total neutron flux normalization instead of the typical thermal flux normalization. This should yield correct reaction rates in ORIGEN-S for any nuclide updated with XSDRN generated cross sections. For all other nuclides, the cross section will weighted assuming a fission spectrum, which is not quite right.  

Let me know if you need additional information.  

Regards

Ian Gauld