Medical Isotope Production Analyses in Kipt Neutron Source Facility

ANL-16/03

MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

Nuclear Engineering Division

About Argonne National Laboratory Argonne is a U.S. Department of Energy laboratory managed by UChicago Argonne, LLC under contract DE-AC02-06CH11357. The Laboratory’s main facility is outside Chicago, at 9700 South Cass Avenue, Argonne, Illinois 60439. For information about Argonne and its pioneering science and technology programs, see www.anl.gov.

DOCUMENT AVAILABILITY

Online Access: U.S. Department of Energy (DOE) reports produced after 1991 and a growing number of pre-1991 documents are available free via DOE’s SciTech Connect (http://www.osti.gov/scitech/)

Reports not in digital format may be purchased by the public from the National Technical Information Service (NTIS): U.S. Department of Commerce National Technical Information Service 5301 Shawnee Rd Alexandria, VA 22312 www.ntis.gov Phone: (800) 553-NTIS (6847) or (703) 605-6000 Fax: (703) 605-6900 Email: [email protected]

Reports not in digital format are available to DOE and DOE contractors from the Office of Scientific and Technical Information (OSTI): U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 www.osti.gov Phone: (865) 576-8401 Fax: (865) 576-5728 Email: [email protected]

Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor UChicago Argonne, LLC, nor any of their employees or officers, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of document authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, Argonne National Laboratory, or UChicago Argonne, LLC.

ANL-16/03

MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

Alberto Talamo and Yousry Gohar Nuclear Engineering Division, Argonne National Laboratory

January 2016

MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

Table of Contents

ABSTRACT ...... 1

I. INTRODUCTION ...... 2

II. COMPUTATIONAL MODEL ...... 2

III. RESULTS ...... 4

III.A. Effective Multiplication Factor ...... 4

III.B. Neutron and Photon Spectra ...... 5

III.C. Specific Activities of Radioactive Isotopes without Considering Self-Shielding Effect ...... 5

III.D. Specific Activity of 99Mo with Self-Shielding effect ...... 5

III.E. Specific Activity of Strong Neutron Absorbers with Self-Shielding ...... 6

IV. CONCLUSIONS ...... 6

ACKNOWLEDGMENTS ...... 7

REFERENCES...... 8

iv MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

List of Figures

Figure 1. Vertical (top plot) and horizontal (bottom plot) cross sections of the model with 37 fuel assemblies and irradiation sample at position 1 ...... 12 Figure 2. Zoom of the vertical cross section for the configuration with 37 fuel assemblies and irradiation sample at position 1 ...... 13 Figure 3. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 1 ...... 14 Figure 4. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 2 ...... 15 Figure 5. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 3 ...... 16 Figure 6. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 1 ...... 17 Figure 7. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 2 ...... 18 Figure 8. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 3 ...... 19 Figure 9. Horizontal cross section of the fuel assembly ...... 20 Figure 10. Neutron spectrum in different irradiation positions ...... 21 Figure 11. Photon spectrum in different irradiation positions ...... 21 Figure 12. 111Ag specific activity as a function of the irradiation time ...... 22 Figure 13. 82Br specific activity as a function of the irradiation time ...... 22 Figure 14. 58Co specific activity as a function of the irradiation time ...... 23 Figure 15. 58Co specific activity as a function of the irradiation time ...... 23 Figure 16. 60Co specific activity as a function of the irradiation time ...... 24 Figure 17. 51Cr specific activity as a function of the irradiation time ...... 24 Figure 18. 64Cu specific activity as a function of the irradiation time ...... 25 Figure 19. 165Dy specific activity as a function of the irradiation time ...... 25 Figure 20. 59Fe specific activity as a function of the irradiation time ...... 26 Figure 21. 159Gd specific activity as a function of the irradiation time ...... 26

v Figure 22. 166Ho specific activity as a function of the irradiation time ...... 27 Figure 23. 192Ir specific activity as a function of the irradiation time ...... 27 Figure 24. 194Ir specific activity as a function of the irradiation time ...... 28 Figure 25. 42K specific activity as a function of the irradiation time ...... 28 Figure 26. 99Mo specific activity as a function of the irradiation time ...... 29 Figure 27. 24Na specific activity as a function of the irradiation time ...... 29 Figure 28. 32P specific activity as a function of the irradiation time ...... 30 Figure 29. 32P specific activity as a function of the irradiation time ...... 30 Figure 30. 33P specific activity as a function of the irradiation time ...... 31 Figure 31. 103Pd specific activity as a function of the irradiation time ...... 31 Figure 32. 103Pd specific activity as a function of the irradiation time ...... 32 Figure 33. 186Re specific activity as a function of the irradiation time ...... 32 Figure 34. 188Re specific activity as a function of the irradiation time ...... 33 Figure 35. 35S specific activity as a function of the irradiation time ...... 33 Figure 36. 47Sc specific activity as a function of the irradiation time ...... 34 Figure 37. 153Sm specific activity as a function of the irradiation time ...... 34 Figure 38. 188W specific activity as a function of the irradiation time ...... 35 Figure 39. 90Y specific activity as a function of the irradiation time ...... 35 99 Figure 40. Mo specific activity from MoO3 irradiation, with self-shielding effect, as a function of the irradiation time for (n,γ) reaction ...... 36 99 Figure 41. Mo specific activity from MoO3 irradiation, with self-shielding effect, as a function of the irradiation time for (γ,n) reaction ...... 36 Figure 42. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 1 ...... 37 Figure 43. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 3 ...... 37 Figure 44. 60Co specific activity, with self-shielding effect, as a function of the irradiation time ...... 38 Figure 45. 64Cu specific activity, with self-shielding effect, as a function of the irradiation time ...... 38 Figure 46. 159Gd specific activity, with self-shielding effect, as a function of the irradiation time ...... 39 Figure 47. 166Ho specific activity, with self-shielding effect, as a function of the irradiation time ...... 39

vi Figure 48. 192Ir specific activity, with self-shielding effect, as a function of the irradiation time ...... 40 Figure 49. 194Ir specific activity, with self-shielding effect, as a function of the irradiation time ...... 40 Figure 50. 186Re specific activity, with self-shielding effect, as a function of the irradiation time ...... 41 Figure 51. 188Re specific activity, with self-shielding effect, as a function of the irradiation time ...... 41 Figure 52. 153Sm specific activity, with self-shielding effect, as a function of the irradiation time ...... 42 Figure 53. 188W specific activity, with self-shielding effect, as a function of the irradiation time ...... 42 Figure 54. 82Br specific activity, with self-shielding effect, as a function of the irradiation time ...... 43 Figure 55. 165Dy specific activity, with self-shielding effect, as a function of the irradiation time ...... 43 Figure 56. 24Na specific activity, with self-shielding effect, as a function of the irradiation time ...... 44 Figure 57. 90Y specific activity, with self-shielding effect, as a function of the irradiation time ...... 44

Figure 58. Capture cross section of the parent nuclides with σγ lower than 10 b at 0.02 eV ...... 45

Figure 59. Capture cross section of the parent nuclides with σγ higher than 10 b at 0.02 eV ...... 45

vii MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

List of Tables

Table I. Effective multiplication factor obtained by MCNPX criticality calculations; the standard deviation is lower than 6 pcm ...... 10 Table II. Position of the irradiation sample that maximizes the specific activity ...... 11

viii MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

Abstract

Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator driven system (ADS), which has a subcritical assembly using low enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99Mo is the parent isotope of 99mTc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

1 MEDICAL ISOTOPE PRODUCTION ANALYSES IN KIPT NEUTRON SOURCE FACILITY

I. Introduction

Argonne National Laboratory (ANL) and Kharkov Institute of Physics and Technology (KIPT) have cooperated on the construction of the Neutron Source Facility (NSF) at KIPT. The NSF facility has an accelerator driven system (ADS) with 100-kW electron accelerator for multiple applications including medical isotope production. ANL performed extensive analyses including medical isotopes production,1,2 reactivity monitoring,3 operations and control,4,5 refueling,6 cold neutron source design,7 target design,8 and radiation shielding.9

The present report focuses on the use of the KIPT ADS for medical isotope production.10-18 Medical isotopes are radioactive isotopes with short half-lives used in diagnostic and therapeutic procedures. For example, brain cancer is difficult to treat by ordinary surgery and only brachytherapy with 131Cs, which has 9.7 days half-life, has shown effective results on the patients.19

99mTc is the most commonly used medical isotope in diagnoses because the wavelength of its gamma ray (8.8 pm wave length) is about the same as the conventional X-ray diagnostic devices. 99mTc has 6 hours half-life, therefore it cannot be stored because it quickly decays into 99Tc. The parent of 99mTc is 99Mo, which has 66 hours half-life. Consequently, the delivery of 99mTc occurs through shipping 99Mo samples to the medical facilities. The present analyses investigated the 99Mo production at the NSF of KIPT due to the importance of 99mTc in medical applications. In recent years, ANL has a lot of activities researching the 99Mo production without using high- enriched uranium.20-23

II. Computational Model

Reference 1 discusses in detail the medical isotope production in the NSF of KIPT. The calculations of this report used an updated detailed MCNPX24 model of the NSF facility and the more recent ENDF/B-VII.0 nuclear data library. Only some of the results of Section III.A are based on the ENDF/B-VII.1 nuclear data library. The analyses considered three irradiation positions in the subcritical assembly. The first position is next to the target, the third position is next to the beryllium reflector, and the second position is between the other two positions. Figures 1 to 9 show different MCNPX cross sections of the KIPT NSF model highlighting the irradiation locations. In Figures 1 to 9, each color corresponds to a different material as follows:

• Orange fuel • Blue aluminum

2 • Cyan water • Pink uranium target • Purple beryllium • Wheat graphite • Pale-green concrete • Yellow air • Red molybdenum (irradiation sample)

The tally multiplier option of MCNPX allowed calculating the average reaction rate in each of the three positions for more than forty different reactions. This part of the analyses aimed at identifying the isotopes suitable for production and their optimal location. In the simulations of Sections III.B to III.D, the reaction rate tallies refer to neutron and gamma fluxes averaged in a cylindrical volume with 0.75 cm radius and 10 cm height. Unless otherwise specified, the KIPT NSF is loaded with 37 fuel assemblies and the computational model does not include the irradiation target material. The analyses with self-shielding (Section III.D), for configurations with 37 and 38 fuel assemblies, took into consideration the modeling of the molybdenum trioxide powder, 3 MoO3 with 4.69 g/cm density. The configurations with 37 and 38 fuel assemblies use uranium and tungsten targets, respectively. The computational model included the aluminum cassette of the irradiation sample. N 0 Equation 1 gives the initial atomic density of the parent nuclide p using: the mass 3 density (in g/cm units) of the parent material dnat, the Avogadro’s number A, the natural abundance of the parent nuclide in the parent material f, and the atomic weight of the parent material W.

d ⋅ A⋅ f N 0 = nat 1) p W

Equation 2b is the solution of Equation set 2a and it gives the atomic density N of the daughter nuclides (medical isotopes) as a function of time.

dN = − λ +σΦ +σ Φ  ( )N p N p dt 2a)  dN  p = −σ p N pΦ  dt

−σ Φ e p t − e−(λ+σΦ)t N(t) = σ ΦN 0 2b) p p λ +σΦ −σ Φ p

In Eqs. 2a and 2b, λ is the decay constant of the daughter nuclide, Np is the density of the parent nuclide, and σp Φ is the parent reaction rate. The reaction rate per source particle (electron), from the MCNPX output file, multiplied by the number of electrons per second, obtained by assuming 100 kW beam power and 100 MeV electron energy (in

3 Ref. 1 the electron energy is 200 MeV), gives σp Φ. The standard deviation of the MCNPX reaction rate values per source particle is generally lower than 1.4%; for (n,2n) reactions, the standard deviation value increases up to 4.5%. The daughter reaction rate (σΦ) has a small value relative to the decay constant, because medical isotopes have a short half-life; consequently, this term has been neglected in the equations.

Equations 3b are the solution of Equation set 3a and give the atomic density of daughter nuclides N generated by a grandparent, with density Ngp, and a parent, with density Np. In the case of a stable parent, Eqs. 3b hold by setting λp equal to zero; in the N 0 case of a decaying parent (as for 47Sc and 188W production), they do by setting p equal to zero.

dN = −(λ +σΦ)N +σ N Φ  dt p p   dN p  = −(λp +σ pΦ)⋅ N p +σ gp N gpΦ 3a)  dt dN  gp = −σ N Φ  gp gp  dt

− λ +σ Φ −σ Φ − λ +σ Φ  e ( p p )t − e−(λ+σΦ)t σ ΦN 0 σ Φ e gp t − e−(λ+σΦ)t e ( p p )t − e−(λ+σΦ)t  N = σ ΦN 0 + p gp gp  −  p p λ +σΦ − λ −σ Φ λ +σ Φ −σ Φ λ +σΦ −σ Φ λ +σΦ − λ −σ Φ  p p p p gp  gp p p   −σ gpΦt −(λp +σ pΦ)t  0 −(λp +σ pΦ)t 0 e − e  N p = N pe +σ gpΦN gp 3b)  λp +σ pΦ −σ gpΦ −σ Φ  N = N 0 e gp t  gp gp  

Equation 6 gives the specific activity, using the atomic densities obtained from the previous formulas.

λN specific activity = 6) d nat

III. Results

III.A. Effective Multiplication Factor

Table I gives the effective multiplication factor (keff) obtained from criticality calculations for different fuel loadings and nuclear data libraries. The impact of nuclear -5 data on the keff value is small, lower than 150pcm (1pcm = 1x10 ). The configuration with 38 fuel assemblies and the tungsten target has a much lower multiplication factor than the configuration with 37 fuel assemblies and the uranium target.

4 III.B. Neutron and Photon Spectra

Figures 10 and 11 show the neutron and photon spectra in different irradiation positions; the fluxes have been normalized first to unity and then to lethargy. The irradiation position 3, next to the beryllium reflector, has the largest thermal neutron flux and the lowest fast neutron flux compared to the other two positions.

The photon spectrum has a smooth profile, as expected from the Bremsstrahlung effect, with exception of some isolated peaks caused by (n, γ) reactions. The peaks at 0.5-0.6, 2.2, and 7.7 MeV are caused by the (n, γ) reaction with 238U, hydrogen, and aluminum nuclei, respectively.25

III.C. Specific Activities of Radioactive Isotopes without Considering Self-Shielding Effect

Figures 12 to 39 show the specific activities for the medical isotopes produced by incident neutrons. After 20 irradiation days, 82Br, 64Cu, 165Dy, 166Ho, 192Ir, 194Ir, 186Re, 188Re and 153Sm have specific activities larger than 100 MBq/mg; 60Co, 51Cr, 159Gd, 24Na, 32P, and 90Y have specific activities between 10 and 100 MBq/mg; 111Ag, 58Co, 125I, 42K, 99Mo, and 32P (via (n,p)) have specific activities between 1 and 10 MBq/mg; and 58Co (via (n,2n)), 59Fe, 33P, 103Pd, 35S, 47Sc, and 188W have specific activities < 1 MBq/mg. Figure 26 shows the specific activity of 99Mo obtained from irradiating natural molybdenum in metallic and trioxide forms.

Table II reports the best positions for generating these isotopes; these positions may change if self-shielding effect is included.1,2 In general, the results show that isotopes generated through large thermal cross sections are better produced in the third position next to the beryllium reflector because of the highest thermal neutron flux at this location. The first position next to the target enhances the production of isotopes generated through resonances or by threshold reactions due to higher epithermal and fast neutron fluxes. The specific activities of the medical isotopes generated through photonuclear reactions are small1 and therefore they have not been considered in the present study.

III.D. Specific Activity of 99Mo with Self-Shielding effect

The self-shielding effect can change the results obtained in Section III.C, for example the 99Mo production. Figures 40 and 41 show the specific activity of 99Mo obtained by (n,γ) and (γ,n) reactions after modeling the parent material (molybdenum trioxide MoO3) in the irradiation sample. The values obtained by the (n,γ) reactions with self-shielding, shown in Fig. 40 are lower than those obtained without self-shielding, shown in Fig. 26, by a factor of 1.4. The specific activities of 99Mo obtained by the 100Mo(γ,n) reaction shown in Fig. 41 are 40 and 12 times smaller than those obtained by the 98Mo(n,γ) reaction shown in Fig. 40 for the configurations with 37 and 38 fuel assemblies, respectively. The configuration with 37 fuel assemblies and the uranium target produces higher specific activities, relative to the configuration with 38 fuel assemblies and the tungsten target, because it has a higher neutron multiplication as

5 shown in Table I. The insertion of the molybdenum trioxide irradiation sample, a cylinder with 0.75 cm radius and 10 cm height, has negligible effect on the effective multiplication factor as shown in Table I.

III.E. Specific Activity of Strong Neutron Absorbers with Self-Shielding

The analysis of this section evaluates the self-shielding effect when the irradiation samples have high absorption neutron cross section values. In this set of simulations, four cylindrical samples have been simultaneously loaded into the aluminum cassette. Each irradiation sample has 0.1 cm radius and 10 cm height. Figures 3 to 8 show position 1, 2, and 3 of the aluminum cassette without the irradiation samples. Figures 42 and 43 show the four locations, A, B, C, and D, of the irradiation samples inside the aluminum cassette. The sample locations A, B, C, and D have cobalt, copper, gadolinium, and holmium irradiation samples, respectively. In other simulations, the previously listed four materials have been replaced first by iridium, rhenium, samarium, and tungsten, and then by bromine, dysprosium, sodium, and yttrium, respectively. Figures 44 to 57 show the specific activity of 60Co, 64Cu, 159Gd, 166Ho, 192Ir, 194Ir, 186Re, 188Re, 153Sm, 188W, 82Br, 165Dy, 24Na, and 90Y, respectively, as a function of the irradiation time. For the previously listed isotopes, the self-shielding effect reduces the specific activity by a factor of 1.9, 1.4, 2.8, 2.3, 7.3, 8.0, 4.1, 2.6, 13.3, 4.5, 1.9, 4.9, 1.1, and 1.1, respectively. The self-shielding effect is proportional to the magnitude of the capture cross section of the irradiated sample material. Figures 58 and 59 plot the microscopic capture cross section (σγ) of the parent nuclides producing the medical isotopes shown in Figs. 12 to 39 through (n,γ) reactions. The parents analyzed in this Section have σγ higher than 30 b at 0.02 eV, a value close to the thermal neutron energy (0.025 eV).

For all isotopes, the optimum irradiation positions for producing the maximum possible activity are the ones found and discussed in Section III.C and listed in Table II, with exception of 153Sm. The insertion of the irradiation samples may lower the effective multiplication factor by 200 pcm as shown in Table I; this reduction also contributes in lowering the specific activity from the analyses with the self-shielding effect.

IV. Conclusions

The NSF of KIPT is the first ADS in the world operating at non-zero power and allows producing several isotopes for medical applications. After 20 irradiation days, 82Br, 64Cu, 165Dy, 166Ho, 192Ir, 194Ir, 186Re, 188Re and 153Sm have specific activities, larger than 100 MBq/mg without taking into account the self-shielding effect and therefore they are good candidates for production. The self-shielding effect plays an important role for all parents that have a large microscopic capture cross section. This effect reduces the reaction rate and therefore the specific activity. For instance, the analyses of molybdenum trioxide irradiation samples have shown that the self-shielding effect may reduce the specific activity by a factor of 1.4. The specific activity of 99Mo, produced

6 from 100Mo by incident photon reactions with natural molybdenum trioxide is small. For 60Co, 64Cu, 159Gd, 166Ho, 192Ir, 194Ir, 186Re, 188Re, 153Sm, 188W, 82Br, 165Dy, 24Na, and 90Y the self-shielding effect reduces the specific activity by a factor of 1.9, 1.4, 2.8, 2.3, 7.3, 8.0, 4.1, 2.6, 13.3, 4.5, 1.9, 4.9, 1.1, and 1.1, respectively.

Acknowledgments

This work is supported by the U.S. Department of Energy, National Nuclear Security Administration, Office of Material Management and Minimization (M3), under Contract No. DE-AC02-06CH11357.

7 References

[1] A. TALAMO and Y. GOHAR, Radioactive Isotope Production for Medical Applications Using Kharkov Electron Driven Subcritical Assembly Facility, Argonne National Laboratory, ANL-07/18, 2007. [2] A. TALAMO and Y. GOHAR, Production of Medical Radioactive Isotopes Using KIPT Electron Driven Subcritical Facility, Applied Radiation and Isotopes 66, pp. 577-586, 2008. [3] Y. CAO et al., Measuring and Monitoring KIPT Neutron Source Facility Reactivity, Argonne National Laboratory, ANL-15/15, 2015. [4] A.L. GRELLE et al., Neutron Source Facility Simulator (NSFS), Argonne National Laboratory, ANL-14/07, 2014. [5] Y. GOHAR et al., Control and Protection System Conceptual Design Logic Diagrams for Neutron Source Facility at the Kharkov Institute of Physics and Technology, Argonne National Laboratory, ANL-13/10, 2013. [6] Z. ZHONG et al., Burnup Calculations for KIPT Accelerator Driven Subcritical Facility Using Monte Carlo Computer Codes – MCB and MCNPX, Argonne National Laboratory, ANL-09/07, 2009. [7] Z. ZHONG et al., Physics Design of a Cold Neutron Source for KIPT Neutron Source Facility, Argonne National Laboratory, ANL-08/36, 2008. [8] T. SOFU et al., Target Design Optimization for an Electron Accelerator Driven Subcritical Facility with Circular and Square Beam Profiles, Argonne National Laboratory, ANL-NE-08/25, 2008. [9] Z. ZHONG et al., Shielding Analysis and Design of the KIPT Experimental Neutron Source Facility of Ukraine, Argonne National Laboratory, ANL-08/23, 2008. [10] IAEA, Manual for Reactor Produced Radioisotopes, International Atomic Energy Agency, IAEA-TECDOC-1340, 2003. [11] COMMITTEE ON MEDICAL ISOTOPES PRODUCTION, Medical Isotope Production without Highly Enriched Uranium, The National Academies Press, ISBN 0-309-13040-9, 2009. [12] S.J. ADELSTEIN et al., Isotopes for Medicine and Life Science, The National Academies Press, ISBN 0-309-05190-8, 1995. [13] S. MIRZADEH et al., Projected Medical Radioisotope Production Capabilities of the Advanced Neutron Source (ANS), Oak Ridge National Laboratory, ORNL/TM- 10210-S, 1994. [14] V.N. STAROVOITOVA et al., Production of Medical Isotopes with Linear Accelerators, Applied Radiation and Isotopes 85, pp. 39-44, 2014. [15] B.I. ZHUIKOV, Production of Medical Radionuclides in Russia: Status and Future – A Review, Applied Radiation and Isotopes 84, pp. 48-56, 2014. [16] B. GUÉRIN et al., Cyclotron Production of 99mTc: An Approach to the Medical Isotope Crisis, The Journal of Nuclear Medicine 51/4, 2010. [17] M. NEVES, A. KLING and R.M. LAMBRECHT, Radionuclide Production for Therapeutic Radiopharmaceuticals, Applied Radiation and Isotopes 57, pp. 657- 664, 2002. [18] K. A. Van RIPER, S.G. MASHNIK and W.B. Wilson, A Computer Study of Radionuclide Production in High Power Accelerators for Medical and Industrial

8 Applications, Nuclear Instruments & Methods in Physics Research A 463, pp. 576- 585, 2001. [19] ISORAY MEDICAL, URL http://www.isoray.com/press-release/, 2015. [20] D.C. STEPINSKI et al., Verification of Column Design for Recovery of Mo from Low-Enriched Uranium Target using Irradiated Target Tracer Solution, Argonne National Laboratory, ANL/CSE-14/14, 2014. [21] D.C. STEPINSKI et al., Development of Recovery and Purification Processes for Mo-99 from an Accelerator-Driven Subcritical target Solution: Determination of Distribution Coefficients for Competing Components and Micro-SHINE Tracer Column Results, Argonne National Laboratory, ANL/CSE-14/12, 2014. [22] P. TKAC et al., Recovery of Mo for Accelerator Production of Mo-99 Using (γ,n) Reaction on Mo-100, Argonne National Laboratory, ANL/CSE-13/45, 2013. [23] J. JERDEN et al., Acid-Dissolution Front-End Process for Mo-99 Recovery at Ambient Pressure: Final Design and Results from Full-Scale Tests, Argonne National Laboratory, ANL/CSE-14/15, 2014. [24] D.B. PELOWITZ et al., MCNPX 2.7A Extensions, LA-UR-08-07182, 2008. [25] IAEA, Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis, ISBN 92–0–101306–X, 2007.

9 Table I. Effective multiplication factor obtained by MCNPX criticality calculations; the standard deviation is lower than 6 pcm

No. FA – Position of the Irradiation Sample Irradiation Sample ENDF/B Materials version 1 2 3 37 – VII.0 0.97094 0.97207 0.97138 37– VII.1 0.96948 0.97061 0.96991 38 – VII.0 Mo 0.95212 0.95324 0.95260 38 – VII.0 0.95254 38 – VII.1 Mo 0.95081 0.95202 0.95137 38 – VII.1 0.95133 37 – VII.0 Br Dy Na Y 0.96995 0.97122 0.97047 37 – VII.0 Co Cu Gd Ho 0.96952 0.97078 0.97018 37 – VII.0 Ir Re Sm W 0.96868 0.97003 0.96949 38 – VII.0 Br Dy Na Y 0.95167 0.95270 0.95194 38 – VII.0 Co Cu Gd Ho 0.95146 0.95230 0.95160 38 – VII.0 Ir Re Sm W 0.95059 0.95163 0.95078

10 Table II. Position of the irradiation sample that maximizes the specific activity Position Number Medical Isotope Without Self-Shielding With Self-Shielding 111Ag 1 - 82Br 1 1 58Co via (n,2n) 1 - 58Co via (n,p) 1 - 60Co 3 3 51Cr 3 - 64Cu 3 3 165Dy 3 3 59Fe 3 - 159Gd 1 1 166Ho 3 3 125I 1 - 192Ir 3 3 194Ir 3 3 42K 3 - 99Mo 1 1 24Na 3 3 32P via (n,γ) 3 - 32P via (n,p) 1 - 33P 1 - 103Pd via (n,γ) 3 - 103Pd via (n,2n) 1 - 186Re 3 3 188Re 3 3 35S 3 - 47Sc 3 - 153Sm 3 1 188W 1 3 90Y 3 3

Figure 1. Vertical (top plot) and horizontal (bottom plot) cross sections of the model with 37 fuel assemblies and irradiation sample at position 1

Electron Beam 100 kW power; 100 MeV energy

Figure 2. Zoom of the vertical cross section for the configuration with 37 fuel assemblies and irradiation sample at position 1

Figure 3. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 1

Figure 4. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 2

Figure 5. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 3

Figure 6. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 1

Figure 7. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 2

Figure 8. Zoom of the horizontal cross section for the configuration with 37 fuel assemblies and irradiation sample at position 3

Figure 9. Horizontal cross section of the fuel assembly

20 Neutron Spectrum Normalized to Unity and Lethargy 1

0.1

1st Position - Φ = 1.96⋅1013 neutrons/cm2⋅s 0.01 n nd Φ ⋅ 13 2⋅ 2 Position - n = 1.88 10 neutrons/cm s rd 13 2 Normalized Neutron Flux / Lethargy Φ ⋅ ⋅ 3 Position - n = 1.7 10 neutrons/cm s

0.001 -8 -7 -6 -5 -4 -3 -2 -1 0 1 10 10 10 10 10 10 10 10 10 10 Energy [MeV] Figure 10. Neutron spectrum in different irradiation positions

0 Photon Spectrum Normalized to Unity and Lethargy 10

-1 10

-2 10

-3 st Φ ⋅ 13 2⋅ 10 1 Position - γ(E<30MeV) = 12.73 10 photons/cm s

Normalized Photon Flux / Lethargy nd 13 2 2 Position - Φγ(E<30MeV) = 5.25⋅10 photons/cm ⋅s rd 13 2 3 Position - Φγ(E<30MeV) = 2.94⋅10 photons/cm ⋅s -4 10 -1 0 1 10 10 10 Energy [MeV] Figure 11. Photon spectrum in different irradiation positions

21 Production of 111Ag: 110Pd(n,γ)111Pd(β)111Ag 1.8

1.6

1.4

1.2

st 1 1 Position 2nd Position 0.8 3rd Position

0.6 Specific Activity [MBq/mg] Activity Specific 0.4

0.2

0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Irradiation Time [d]

Figure 12. 111Ag specific activity as a function of the irradiation time

Production of 82Br: 81Br(n,γ)82Br 140

120

100

80 1st Position 2nd Position 60 3rd Position

Specific Activity [MBq/mg] Activity Specific 40

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 13. 82Br specific activity as a function of the irradiation time

22 Production of 58Co: 59Co(n,2n)58Co 0.012

0.01

0.008

0.006

0.004 Specific Activity [MBq/mg] Activity Specific 1st Position 0.002 2nd Position 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 14. 58Co specific activity as a function of the irradiation time

Production of 58Co: 58Ni(n,p)58Co 3.5

2.5

1.5

Specific Activity [MBq/mg] Activity Specific 1 1st Position nd 0.5 2 Position 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 15. 58Co specific activity as a function of the irradiation time

23 Production of 60Co: 59Co(n,γ)60Co 150

100

50 Specific Activity [MBq/mg] Activity Specific 1st Position 2nd Position 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 16. 60Co specific activity as a function of the irradiation time

Production of 51Cr: 50Cr(n,γ)51Cr 40

Specific Activity [MBq/mg] Activity Specific 10 1st Position 2nd Position 5 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 17. 51Cr specific activity as a function of the irradiation time

24 Production of 64Cu: 63Cu(n,γ)64Cu 150

100

1st Position 2nd Position 3rd Position

50 Specific Activity [MBq/mg] Activity Specific

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 18. 64Cu specific activity as a function of the irradiation time

Production of 165Dy: 164Dy(n,γ)165Dy 14000

12000

10000

8000

6000

Specific Activity [MBq/mg] Activity Specific 4000 1st Position nd 2000 2 Position 3rd Position

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 19. 165Dy specific activity as a function of the irradiation time

25 Production of 59Fe: 58Fe(n,γ)59Fe 0.18

0.16

0.14

0.12

0.1

0.08

0.06 Specific Activity [MBq/mg] Activity Specific st 0.04 1 Position 2nd Position 0.02 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 20. 59Fe specific activity as a function of the irradiation time

Production of 159Gd: 158Gd(n,γ)159Gd 45

st 25 1 Position 2nd Position 20 3rd Position

15 Specific Activity [MBq/mg] Activity Specific 10

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 21. 159Gd specific activity as a function of the irradiation time

26 Production of 166Ho: 165Ho(n,γ)166Ho 2500

2000

1500 1st Position 2nd Position 3rd Position 1000 Specific Activity [MBq/mg] Activity Specific

500

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 22. 166Ho specific activity as a function of the irradiation time

Production of 192Ir: 191Ir(n,γ)192Ir 6000

5000

4000

3000

2000 Specific Activity [MBq/mg] Activity Specific 1st Position 1000 2nd Position 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 23. 192Ir specific activity as a function of the irradiation time

27 Production of 194Ir: 193Ir(n,γ)194Ir 2500

2000

1500 1st Position 2nd Position 3rd Position 1000 Specific Activity [MBq/mg] Activity Specific

500

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 24. 194Ir specific activity as a function of the irradiation time

Production of 42K: 41K(n,γ)42K 8

5 1st Position 4 2nd Position 3rd Position 3

Specific Activity [MBq/mg] Activity Specific 2

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 25. 42K specific activity as a function of the irradiation time

28 Production of 99Mo: 98Mo(n,γ)99Mo 7

1st Position - Metal Mo 3 2nd Position - Metal Mo 3rd Position - Metal Mo

Specific Activity [MBq/mg] Activity Specific 2 st 1 Position - MoO3 nd 1 2 Position - MoO3 rd 3 Position - MoO3 0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 26. 99Mo specific activity as a function of the irradiation time

Production of 24Na: 23Na(n,γ)24Na 70

40 1st Position 2nd Position 30 3rd Position

Specific Activity [MBq/mg] Activity Specific 20

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 27. 24Na specific activity as a function of the irradiation time

29 Production of 32P: 31P(n,γ)32P 18

6 Specific Activity [MBq/mg] Activity Specific st 4 1 Position 2nd Position 2 3rd Position

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 28. 32P specific activity as a function of the irradiation time

Production of 32P: 32S(n,p)32P 6

2 Specific Activity [MBq/mg] Activity Specific 1st Position 1 2nd Position 3rd Position

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 29. 32P specific activity as a function of the irradiation time

30 Production of 33P: 33S(n,p)33P 0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015 Specific Activity [MBq/mg] Activity Specific 1st Position 0.01 2nd Position 0.005 3rd Position

0 0 10 20 30 40 50 60 70 80 90 100 Irradiation Time [d]

Figure 30. 33P specific activity as a function of the irradiation time

Production of 103Pd: 102Pd(n,γ)103Pd 0.9

0.8

0.7

0.6

st 0.5 1 Position 2nd Position 0.4 3rd Position

0.3 Specific Activity [MBq/mg] Activity Specific 0.2

0.1

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 31. 103Pd specific activity as a function of the irradiation time

31 -3 103 104 103 x 10 Production of Pd: Pd(n,2n) Pd 2.5

1.5

1 Specific Activity [MBq/mg] Activity Specific 1st Position 0.5 2nd Position 3rd Position

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 32. 103Pd specific activity as a function of the irradiation time

Production of 186Re: 185Re(n,γ)186Re 1600

1400

1200

1000 1st Position 800 2nd Position 3rd Position 600

Specific Activity [MBq/mg] Activity Specific 400

200

0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Irradiation Time [d]

Figure 33. 186Re specific activity as a function of the irradiation time

32 Production of 188Re: 187Re(n,γ)188Re 1000

900

800

700

600 1st Position 500 2nd Position 3rd Position 400

300 Specific Activity [MBq/mg] Activity Specific

200

100

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 34. 188Re specific activity as a function of the irradiation time

Production of 35S: 34S(n,γ)35S 0.7

0.6

0.5

0.4

0.3

Specific Activity [MBq/mg] Activity Specific 0.2 1st Position nd 0.1 2 Position 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 35. 35S specific activity as a function of the irradiation time

33 Production of 47Sc: 45Sc(n,γ)46Sc(n,γ)47Sc 0.5

0.45 1st Position 2nd Position 0.4 3rd Position 0.35

0.3

0.25

0.2

0.15 Specific Activity [MBq/mg] Activity Specific

0.1

0.05

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 36. 47Sc specific activity as a function of the irradiation time

Production of 153Sm: 152Sm(n,γ)153Sm 2500

2000

1500 1st Position 2nd Position 3rd Position 1000 Specific Activity [MBq/mg] Activity Specific

500

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 37. 153Sm specific activity as a function of the irradiation time

34 Production of 188W: 186W(n,γ)187W(n,γ)188W 0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015 Specific Activity [MBq/mg] Activity Specific 1st Position 0.01 2nd Position 0.005 3rd Position

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 38. 188W specific activity as a function of the irradiation time

Production of 90Y: 89Y(n,γ)90Y 45

15 Specific Activity [MBq/mg] Activity Specific st 10 1 Position 2nd Position 5 3rd Position

0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Irradiation Time [d]

Figure 39. 90Y specific activity as a function of the irradiation time

35 Production of 99Mo: 98Mo(n,γ)99Mo 3.5

2.5 1st Position - 37 FA 2nd Position - 37 FA 2 3rd Position - 37 FA 1st Position - 38 FA 1.5 2nd Position - 38 FA 3rd Position - 38 FA

Specific Activity [MBq/mg] Activity Specific 1

0.5

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

99 Figure 40. Mo specific activity from MoO3 irradiation, with self-shielding effect, as a function of the irradiation time for (n,γ) reaction Production of 99Mo: 100Mo(γ,n)99Mo 0.09

0.08

0.07

0.06 1st Position - 37 FA 2nd Position - 37 FA 0.05 3rd Position - 37 FA st 0.04 1 Position - 38 FA 2nd Position - 38 FA 0.03 3rd Position - 38 FA Specific Activity [MBq/mg] Activity Specific

0.02

0.01

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

99 Figure 41. Mo specific activity from MoO3 irradiation, with self-shielding effect, as a function of the irradiation time for (γ,n) reaction

B C A D

Figure 42. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 1

B C A D

Figure 43. Zoom of the horizontal cross section for the configuration with 38 fuel assemblies and irradiation sample at position 3

37 Production of 60Co: 59Co(n,γ)60Co 80

1st Position - 37 FA 70 2nd Position - 37 FA 3rd Position - 37 FA 60 1st Position - 38 FA nd 50 2 Position - 38 FA 3rd Position - 38 FA

30 Specific Activity [MBq/mg] Activity Specific 20

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 44. 60Co specific activity, with self-shielding effect, as a function of the irradiation time Production of 64Cu: 63Cu(n,γ)64Cu 120

100

80 1st Position - 37 FA 2nd Position - 37 FA 60 3rd Position - 37 FA 1st Position - 38 FA nd 40 2 Position - 38 FA

Specific Activity [MBq/mg] Activity Specific 3rd Position - 38 FA

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 45. 64Cu specific activity, with self-shielding effect, as a function of the irradiation time

38 Production of 159Gd: 158Gd(n,γ)159Gd 15

1st Position - 37 FA 10 2nd Position - 37 FA 3rd Position - 37 FA 1st Position - 38 FA 2nd Position - 38 FA 3rd Position - 38 FA 5 Specific Activity [MBq/mg] Activity Specific

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 46. 159Gd specific activity, with self-shielding effect, as a function of the irradiation time Production of 166Ho: 165Ho(n,γ)166Ho 1000

900

800

700 1st Position - 37 FA 2nd Position - 37 FA 600 3rd Position - 37 FA 500 1st Position - 38 FA 2nd Position - 38 FA 400 3rd Position - 38 FA 300 Specific Activity [MBq/mg] Activity Specific

200

100

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 47. 166Ho specific activity, with self-shielding effect, as a function of the irradiation time

39 Production of 192Ir: 191Ir(n,γ)192Ir 800 1st Position - 37 FA 2nd Position - 37 FA 700 3rd Position - 37 FA st 600 1 Position - 38 FA 2nd Position - 38 FA rd 500 3 Position - 38 FA

400

300 Specific Activity [MBq/mg] Activity Specific 200

100

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 48. 192Ir specific activity, with self-shielding effect, as a function of the irradiation time Production of 194Ir: 193Ir(n,γ)194Ir 300

250

1st Position - 37 FA nd 200 2 Position - 37 FA 3rd Position - 37 FA 1st Position - 38 FA 150 2nd Position - 38 FA 3rd Position - 38 FA

100 Specific Activity [MBq/mg] Activity Specific

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 49. 194Ir specific activity, with self-shielding effect, as a function of the irradiation time

40 Production of 186Re: 185Re(n,γ)186Re 400

350

300 1st Position - 37 FA 250 2nd Position - 37 FA 3rd Position - 37 FA 200 1st Position - 38 FA 2nd Position - 38 FA 150 3rd Position - 38 FA Specific Activity [MBq/mg] Activity Specific 100

0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Irradiation Time [d]

Figure 50. 186Re specific activity, with self-shielding effect, as a function of the irradiation time Production of 188Re: 187Re(n,γ)188Re 400

350

300

1st Position - 37 FA 250 2nd Position - 37 FA 3rd Position - 37 FA 200 1st Position - 38 FA 2nd Position - 38 FA 150 3rd Position - 38 FA Specific Activity [MBq/mg] Activity Specific 100

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 51. 188Re specific activity, with self-shielding effect, as a function of the irradiation time

41 Production of 153Sm: 152Sm(n,γ)153Sm 180

160

140 1st Position - 37 FA 2nd Position - 37 FA 120 3rd Position - 37 FA 100 1st Position - 38 FA 2nd Position - 38 FA 80 3rd Position - 38 FA

60 Specific Activity [MBq/mg] Activity Specific

0 0 5 10 15 20 25 30 35 40 45 50 55 60 Irradiation Time [d]

Figure 52. 153Sm specific activity, with self-shielding effect, as a function of the irradiation time Production of 188W: 186W(n,γ)(n,γ)188W 0.012 1st Position - 37 FA 2nd Position - 37 FA 0.01 3rd Position - 37 FA 1st Position - 38 FA 0.008 2nd Position - 38 FA 3rd Position - 38 FA

0.006

0.004 Specific Activity [MBq/mg] Activity Specific

0.002

0 0 20 40 60 80 100 120 140 160 180 200 Irradiation Time [d]

Figure 53. 188W specific activity, with self-shielding effect, as a function of the irradiation time

42 Production of 82Br: 81Br(n,γ)82Br 70

60 1st Position - 37 FA 2nd Position - 37 FA 50 3rd Position - 37 FA 1st Position - 38 FA 40 2nd Position - 38 FA 3rd Position - 38 FA 30

Specific Activity [MBq/mg] Activity Specific 20

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 54. 82Br specific activity, with self-shielding effect, as a function of the irradiation time Production of 165Dy: 164Dy(n,γ)165Dy 3000

2500

2000 1st Position - 37 FA 2nd Position - 37 FA 3rd Position - 37 FA 1500 1st Position - 38 FA 2nd Position - 38 FA 1000 3rd Position - 38 FA Specific Activity [MBq/mg] Activity Specific

500

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d] Figure 55. 165Dy specific activity, with self-shielding effect, as a function of the irradiation time

43 Production of 24Na: 23Na(n,γ)24Na 70

50 1st Position - 37 FA 2nd Position - 37 FA 40 3rd Position - 37 FA 1st Position - 38 FA 30 2nd Position - 38 FA 3rd Position - 38 FA

Specific Activity [MBq/mg] Activity Specific 20

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Irradiation Time [d]

Figure 56. 24Na specific activity, with self-shielding effect, as a function of the irradiation time Production of 90Y: 89Y(n,γ)90Y 40

25 1st Position - 37 FA 20 2nd Position - 37 FA 3rd Position - 37 FA 15 1st Position - 38 FA nd

Specific Activity [MBq/mg] Activity Specific 2 Position - 38 FA 10 3rd Position - 38 FA

0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Irradiation Time [d] Figure 57. 90Y specific activity, with self-shielding effect, as a function of the irradiation time

44 σ Parent Nulides with γ < 10 b at 0.02 eV

2 81 10 Br 63Cu 58Fe 158 1 Gd 10 41K 98Mo [b] γ 23Na σ 0 10 31P 102Pd 110Pd 34 -1 S 10 132Xe 89Y

-11 -10 -9 -8 -7 -6 10 10 10 10 10 10 Neutron Energy [MeV] Figure 58. Capture cross section of the parent nuclides with σγ lower than 10 b at 0.02 eV σ Parent Nulides with γ > 10 b at 0.02 eV

5 10

59Co 50Cr 4 10 164Dy 165Ho 191Ir 3 10 193Ir [b] γ 185 σ Re 187Re 2 10 45Sc 152Sm 186W 1 10 124Xe

-11 -10 -9 -8 -7 -6 10 10 10 10 10 10 Neutron Energy [MeV] Figure 59. Capture cross section of the parent nuclides with σγ higher than 10 b at 0.02 eV

Nuclear Engineering Division Argonne National Laboratory 9700 South Cass Avenue, Bldg. 208 Argonne, IL 60439 www.anl.gov

Argonne National Laboratory is a U.S. Department of Energy laboratory managed by UChicago Argonne, LLC