Production of industrial and medical radioisotopes in accelerator production of tritium

180 Pages·2012·7.61 MB·English

by  Tiyapun, Kanokrat

AN ABSTRACT OF THE THESIS OF

Kanokrat Tiyapun for the degree of Doctor of Philosophy in Radiation Health Physics
presented on May 25, 20:00.? Title': Productio;n( o,f Industrial and Medical Radioisotopes in
Accelerator Production ~AP? ~.
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Abstractapproved:
Stephen E. Binney
The accelerator production of tritium (APT) has attained an interested in radioisotope
production. The unique design ofAPT would deliver the most powerful and high-energy
beam ofprotons with 170 MW beam power and 1.7 GeV beam energy, to a target for
radionuclide production. The production rate for each reaction has been calculated using
the MCNPX codes. The reaction cross section for this study has been generated using the
LAHET, MCNP4B and HTAPE codes. The generated cross sections were compared with
the experimental cross sections. The double-wall tubes with 2 em-diameter and 200.cm­
height were inserted 3 em behind 13 tungsten neutron source ladders in APT.
Radioisotope production was analyzed to determine the radiopurity and production rate in
13 double wall tubes. The results show that the neutron and proton fluxes were greatest
in the middle segment and decreasing towards the top and the bottom ofthe tubes.
Therefore, the middle segment was used for presentation of the radioisotope production.
The highest neutron flux is 7 .88x 1014 ± 0.56% in the middle segment of a tube behind
fifth ladder. The highest proton flux is 1.65x 1014 ± 0.76%, obtained from the middle
segment ofa tube behind first ladder. The successive decay differential equation
calculation was used to account for time dependent effects because the MCNPX code
does not integrate time dependent behavior. In these calculations, the neutron flux level
and spectra are assumed to remain constant over the irradiation period. Some examples
ofradionuclides that could be produced by proton induced reactions are 72As, 128Ba, 7Be,
139Ce, 56Co, 18F, min, 103Pd and 48V. The example ofradionuclides by neutron reaction
includes 74As, 14C, 6°Co, 165Dy, 18F, 99Mo, 33P, 35S, 99mTc, 117Sn, and 65Zn. The results
show that high production rate and high radiopurity of several radioisotopes can be
achieved using high-energy neutron and proton fluxes from APT. A comparison ofthe
e
production yield for some radionuclides 2P and 67Cu) using CINDER'90 between this
study and preliminary calculations from LANL shows that the deviation is within 6.4% to
7 .6%. The calculation method used in this study specifically for APT target design can
also be applied to any other accelerator design.
©Copyright by Kanokrat Tiyapun

May 25,2000

All Rights Reserved
Production of Industrial and Medical Radioisotopes in Accelerator Production
of Tritium (APT)

by

Kanokrat Tiyapun

A THESIS

submitted to

Oregon State University

in partial fulfillment of
the requirements for the
degree of
Doctor of Philosophy
Presented May 25, 2000

Commencement June 2000
Doctor of Philosophy thesis ofKanokrat Tiyapun presented on May 25, 2000
APPROVED:
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Redacted for Privacy
Healonepartillent ofNuclear Engineering
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Dean of Gra u chool
I understand that my thesis will become part ofthe permanent collection of Oregon State
University libraries. My signature below authorizes release ofmy thesis to any reader
upon request.
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Kanokrat Tiyapun, Author
ACKNOWLEDGMENT

I appreciate the helpful suggestions and guidance for improving my thesis from
Dr. Stephen E. Binney, my major professor and advisor, who was involved in the design,
analysis, interpretation and examination of various drafts. I would like to thank the
member of my committees: Dr. Andrew C. Klein, Dr. Todd S. Palmer, Dr. David Hamby
Dr. Shoichi Kimura and Dr. Fred L. Ramsey for final editing. I am grateful and want to
express my sincere appreciation to Eric Pitcher and his colleague from Los Alamos
National Laboratory who assisted in creating the Accelerator Production of Tritium
(APT) input file and demonstrate how to generate cross section from MCNPX code. I
also wish to thank Dr. Todd S. Palmer for his generous help in the interpretation ofdata
and installation ofMCNPX code. Special thanks are extended to Laurie S. Waters, who
provided MCNPX beta version for the calculation. Finally, without the encouragement of
my mother (Rajanee Tiyapun), my father (Nimit Tiyapun), my sister (Chittima Tiyapun)
and my brother (Theerayut Toojinda), this work would not have been possible.
TABLE OF CONTENTS

INTRODUCTION ............................................................................................... 1

Medical Isotope Production Requirements ....................................................... 3

Reactor Produced Radionuclides ....................................................................... 5

Accelerator Produced Radionuclides .............................................................. 11

Accelerator Production of Tritium (APT) Produced Radionuclides .............. 16

APT Background .............................................................................................. 28

The APT Capability in Medical Isotope Production ....................................... 29

Calculated Isotope Production from Los Alamos National Laboratory ......... 29

Objectives ofthe Study.................................................................................... 32

Scope ofthe Study ........................................................................................... 33

APT Facility Description ................................................................................. 34

Isotope Production Concept ............................................................................. 35

The Accelerator System ................................................................................... 36

The Target /Blanket Assembly (T/B assembly) .............................................. 38

Proton Beam Window .................................................................................... 38

Tungsten Neutron Source .............................................................................. 39

Decoupler ....................................................................................................... 40

Lateral Blanket ............................................................................................... 41

Reflector ......................................................................................................... 4 3

Upstream and Downstream Blanket .............................................................. 43

Shield.............................................................................................................. 44

Upper Vessel Internal Structures ................................................................... 44

Gas Handling Systems ................................................................................... 44

Cavity Vessel System .................................................................................... 44

SPALLATION PHYSICS ................................................................................. 45
TABLE OF CONTENTS (Continued)
COMPUTATIONAL TOOL ............................................................................. 49

Physics Model .................................................................................................. 49

Intranuclear Cascade Models ......................................................................... 49

Multistage pre-equilibrium Models (MPM) .................................................. 50

Fermi Breakup Model, Evaporation Model

and High-Energy Fission Model ................................................................... 50

Physics Module Options .................................................................................. 50

HTA PE3X Code .............................................................................................. 52

Cross Section Models and Nuclear Data Tables ............................................. 52

Nuclear Data Libraries ................................................................................... 53

LA150 Proton and Neutron Libraries ............................................................ 53

Higher Energy Tables .................................................................................... 54

Photoelectric Interaction ................................................................................ 55

Cross Section Models .................................................................................... 55

Experimental Cross Section Data .................................................................. 57

APT MODELING .............................................................................................. 59

ISOTOPE PRODUCTION ................................................................................ 63

Cross Section Models ...................................................................................... 63

MCNPX Input File ........................................................................................... 64

Mesh Tally ........................................................................................................ 66

Radionuclide Production Equations ................................................................ 68

Radiopurity....................................................................................................... 71

RESULTS AND DISCUSSION ....................................................................... 72

Radionuclide Production Results ..................................................................... 83

Time Dependence of Radionuclides................................................................ 85
TABLE OF CONTENTS (Continued)
Page

Comparing Results ........................................................................................... 92

SUMMARY ..................................................................................................... 108

CONCLUSION ................................................................................................ 113

BIBLIOGRAPHY............................................................................................ 115

APPENDICES ................................................................................................. 124
LIST OF FIGURES

1. APT plant layout ............................................................................................ 36

2. Baseline linac design ...................................................................................... 36

3. The high energy beam transport system (HEBT) ......................................... 38

4. Target/Blanket Major Design Features ......................................................... 39

5. Tungsten neutron source ................................................................................ 40

6. Target/blanket module with decouple region ................................................ 41

7. Target/blanket layout in top and front view .................................................. 42

8. Typical blanket assembly ............................................................................... 42

9. The spallation process (intranuclear cascade and evaporation) .................... 47

10. The comparison between the model cross section

and experimental cross section for 160(p, 5n+5pfBe................................. 56

11. The comparison between the model cross section

and experimental cross section for 59Co(p, 2n+pi7Co ............................... 57

12. The comparison between the model cross section

58
and experimental cross section for Ni(p, 2n+p i~i................................. 57

13. Top view ofthe T/B geometry .................................................................... 60

14. Side view ofthe T/B assembly geometry .................................................... 60

15. Front view ofT/B geometry ........................................................................ 61

16. Rabbit tubes for target irradiation ................................................................ 62

17. The neutron axial profile in a rabbit located behind the 5th ladder............. 73

18. The proton axial profile in a rabbit located behind the 2"d ladder .............. 73

19. Neutron fluxes and errors in each rabbit tube behind ladders .................... 74