1. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 1 Multi-group Model Wide neutron spectrum. One-group, two-group? Should be generalized. Identify the terms, NOW. Fraction of an eV

2. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 2 Multi-group Model Total fission Fraction Scattering in Other sources Leakage Scattering out Absorption Fraction of an eV

3. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 3 Multi-group Model 5-group example. Maxwellian 1/E Fission

4. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 4 Multi-group Model Total fission Thermal fission (~ 97%) Fast fission (~ 3%)

5. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 5 Multi-group Model Scattering in Upscattering!!???

6. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 6 Multi-group Model Scattering out

7. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 7 Multi-group Model Group 3 Removal cross section

8. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 8 Multi-group Model Total fission Fraction Scattering in Other sources LeakageRemovalIn-group Scattering Net Scattering in

9. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 9 Multi-group Model Calculate group-averaged: Or for, we need group-averaged

10. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 10 Multi-group Model Group-averaged parameters? ENDF. Integrate term by term over groups and equate to equation of multi-group model. Units!

11. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 11 Multi-group Model Define group flux

12. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 12 Multi-group Model

13. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 13 Multi-group Model

14. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 14 Multi-group Model

15. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 15 Multi-group Model

16. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 16 Multi-group Model

17. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 17 Multi-group Model ENDF High G, few mesh points. Small G, more mesh points. Poison, burnup, temperature, control rod position, etc… Flux

18. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 18 Multi-group Model What could make life a little easier?! No upscattering set group G to include neutrons up to ~1 eV. No group skipping when scattering down (directly coupled). Your choice of how to tackle in-scattering. HW 27 HW 27 How can we pledge this? What about H?

19. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 19 Multi-group ModelCriticality No upscatter Not only sinks Not all sources, only fission. Iterations.

20. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 20 Multi-group Model No upscatter Iterations.

21. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 21 Multi-group Model No upscatter Directly coupled Iterations.

22. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 22 Multi-group Model Multi-group one-group

23. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 23 Multi-group Model

24. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 24 Multi-group Model

25. Substituting all of the above into yields which is the one-group diffusion equation. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 25 Multi-group Model

26. Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh). 26 Multi-group Model Project 4 multi-group to two-group Work out the multi-group to two-group collapsing and investigate criticality. Very important!!! Happy Eid.