Photonuclear approach Sergey Chemerisov 1 , George Vandegrift 1 , - - PowerPoint PPT Presentation

Accelerator Based Domestic Production of 99Mo: Photonuclear approach

Mo-99 Topical meeting Washington, DC June 26, 2014

Sergey Chemerisov1, George Vandegrift1, Gregory Dale2, Peter Tkac1, Roman Gromov1, Bradley Micklich1, Charles Jonah1, Vakho Makarashvili1 Keith Woloshun2, Michael Holloway2, Frank Romero2 and James Harvey3

1Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, chemerisov@anl.gov 2Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, gedale@lanl.gov 3NorthStar Medical Technologies, LLC, 706 Williamson Street, Madison, WI 53703,

jharvey@northstarnm.com

10 20 30 1 2 3 4 5 flux (1011/cm2/s/A) energy (MeV) 50 100 150 cross section (mb)

20 MeV 35 MeV

(,n)

Proof of Concept Demonstrations for Electron Accelerator Production of 99Mo

• Under the direction of the NNSA, ANL and LANL are partnering with NorthStar Nuclear Medicine,
• LLC. to demonstrate and develop accelerator production of 99Mo through the 100Mo(,n)99Mo

reaction. – The threshold for the reaction is 9 MeV. – The peak cross section is 150 mb at 14.5 MeV.

• High energy photons are created with a high power electron beam through bremsstrahlung.
• Enriched 100Mo should be commercially available for $400-$600 per gram for kg quantities.

Comparison of the bremsstrahlung photon spectra produced with 20- and 35-MeV electron beams in a Mo target compared with photonuclear cross section of

100Mo.

Scaled Accelerator Tests at Argonne National Laboratory

Seven tests have been performed using the electron accelerator at Argonne.

Date Test April 2010 Water-cooled target test using natural Mo targets, produced 236 µCi of 99Mo. May 2010 Water-cooled target test using natural Mo targets, produced 377 µCi of 99Mo. July 2010 Water-cooled production test using enriched

100Mo targets, produced 10.5 mCi of 99Mo.

April 2011 Once-through gaseous-helium-cooled thermal test using natural Mo targets, 145 µCi of 99Mo. March 2012 Closed-loop gaseous helium thermal test using natural Mo targets. July 2013 1000-hour He cooling system test April 2014 Latest thermal test at 35 and 42 MeV with closed-loop He cooling.

Latest Thermal Performance Test

April 2014

4

• Successfully conducted the thermal test of the 12 mm Mo target

and irradiated an instrumented target at 35 and 42 MeV beam energy and power on the target up to 17 kW.

• Thermal data for the target were acquired at different He pressures

and flows in the cooling loop. The target performed well.

• Results of the experiment are being analyzed. There are several

improvements/issues that have to be addressed.

• Shielding for the OTR and IR cameras has to be improved. There

were multiple recoverable communication issues with both the IR and OTR cameras.

Closed Loop Gaseous Helium Cooling System Layout

Motor Blower Mass Flow Meter Filter Pressure Vessel Heat Exchangers Target

The roots blower is used to move the He through the loop and across the targets. The PV is used to increase the base pressure of the system to 300 psi.

Future Work (August – October 2014)

Production Test Matrix

Production Test 1 Production Test 2 Production Test 3 Production Test 4 Thermal Test Production Test 5 Purpose Test Enrichment 1 at high energy Test Enrichment 2 at high energy Test Enrichment 3 at high energy Test Enrichment 2 at low energy Validate the thermal performance of the target Test Enrichment 4 at high energy for long duration Energy (MeV) 42 42 42 35 42 and 35 42 Current (uA) 240 240 240 500 300 and 550 240 Power (kW) 21 21 21 17.5 12.6 and 19.3 21 Duration (hours) 24 24 24 24 2 156 Targets E1 (97.39%) and Natural E2 (99.03%) and Natural E3 (95.08%) and Natural E2 (99.03%) and Natural Natural E4 (95.08%) and Natural Mo-99 EOB Activity [Ci] 5.4 5.3 5.3 9.6 0.2 and 0.28 19.2 Target Thermocouples No No No No Yes No

7

LINAC upgrade

Energy (MeV) 15 20 25 30 35 40 45 50 55 Beam Peak Current (mA) 1390 1230 1060 900 740 570 390 240 80 Average Beam Current (A) 1112 984 848 720 592 456 312 192 64 Average beam power on the target (kW) 16.76 19.64 21.32 21.6 20.66 18.28 14.2 9.6 3.6

Beam parameters after upgrade (MEVEX proposal)

July 2011 Order for new accelerator structures and circulators was placed September 2012 Structures arrived November 2012 Circulators arrived January 2013 Installation completed, first beam measurements February 2013 Consultation with MEVEX on low beam-energy March 2013 RF measurements with MEVEX engineers and repair of circulator 1 April 2013 Second RF measurements. Problem is localized to the circulators being inadequate June 2013 New circulators are ordered September 2013 New circulators have arrived October 2013 New circulators have been installed. Arcing in circulator 1 November 2013 Sent circulator for repair January 2014 Repaired circulator arrived and installed February 2014 RF conditioning started March 2014 Beam tests and start of normal operation

Accelerator performance

8

5 10 15 20 25 20 25 30 35 40 45 50 Average Beam Power, kW Beam Energy, MeV 36MW 1 36MW 2 36MW 3

• Poly. (36MW 1)
• Poly. (36MW 2)
• Poly. (36MW 3)

Completely upgraded linac

New RF circulators Load lines for upgraded linac

Production facility beam line design

9

FODO doublet Raster magnet 10 degree magnet Test beam line at Argonne 10 degree prototype magnet

10

MNCPX calculations for Mo-99 production

Target:

• 25 disks
• 1 mm thick
• 12 mm diameter

Increase of beam energy decreases peak power in the target and thermal load on the window.

Side-Reaction Modeling of 95.08% Enriched Mo-100 Target

11

30 MeV 18 kW beam 24 h Irradiation 35 MeV 24.5 kW beam 24 h Irradiation

Side-Reaction Modeling at 42 MeV for 95.08 enriched Mo-100

12

0.9990 0.9991 0.9992 0.9993 0.9994 0.9995 0.9996 0.9997 0.9998 0.9999 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Disks

(Mo99+Tc99m)/Total

8h 16h 24h 48h 72h 168h

Mo99/Tc99m purity Disk-by-disk 29.4 kW (700 µA) 24 h Irradiation 95.08% Enriched Mo100 Target

European Pharmacopoeia Requirement

Latest Experimental Design

MCNPX Results

13

Latest Experimental Design

MCNPX Results

14

MCNPX Calculations for Production-Facility Shielding

15

1.0E-02 1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03 0.01 0.1 1 10 100 cross section (cm2/g) photon energy (MeV) concrete lead 0.0E+00 1.0E-01 2.0E-01 3.0E-01 4.0E-01 5.0E-01 6.0E-01 5 10 15 20 cross section (cm2/g) neutron energy (MeV) concrete lead

Draft layout of the proposed accelerator facility Neutron and photon cross sections for lead and concrete

16

MCNPX Calculations for Production-Facility Shielding

neutron source photon source concrete thickness (cm) neutron dose rate (rem/hr) photon dose rate (rem/hr) neutron dose rate (rem/hr) photon dose rate (rem/hr) total dose rate (rem/hr) 150 3.84e-4 2.87e-3 2.65e-2 2.57e-1 2.87e-1 200 5.34e-6 1.15e-4 3.34e-4 1.02e-2 1.07e-2 250 8.50e-8 4.93e-6 4.56e-6 4.61e-4 4.71e-4 neutron source photon source concrete thickness (cm) neutron dose rate (rem/hr) photon dose rate (rem/hr) neutron dose rate (rem/hr) photon dose rate (rem/hr) total dose rate (rem/hr) 100 8.74e+0 2.27e+1 5.32e-1 1.47e+0 3.34e+1 200 7.78e-4 1.70e-2 3.40e-5 9.49e-4 1.88e-2 250 8.88e-6 6.04e-4 3.42e-7 3.34e-5 6.46e-4 Dose rate for primary and secondary radiations in shield of 30 cm lead + concrete for 120 kW of 42-MeV electrons incident on molybdenum.

0° emission. 90° emission.

1.0E+0 1.0E+1 1.0E+2 1.0E+3 1.0E+4 1.0E+5 1.0E+6 1.0E+7 1.0E+8 1.0E+9 10 20 30 40 photon yield (photons/sr/MeV) photon energy (MeV) 0-2 deg 15-20 deg 55-60 deg 85-95 deg 1.0E+4 1.0E+5 1.0E+6 1.0E+7 1.0E+8 1.0E+9 5 10 15 20 neutron yield (neutrons/cm2/MeV) neutron energy (MeV) 0-5 deg 25-35 deg 85-95 deg 115-125 deg 0-180 deg

Dose Calculations For Production-Target Housing

17

1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+00 1.00E+01 20 40 60 80 100 activity (Ci) decay time (days) total Co 58m Ni 57 Cr 51 Nb 92m Co 58 Cr 49 Nb 91m Mn 56 1.00E+01 1.00E+02 1.00E+03 1.00E+04 20 40 60 80 100 dose rate (mR/hr) at 1 meter decay time (days) Inconel windows + structure Inconel windows + SS-304 structure

Substitution of the Inconel for stainless steel will reduce dose by the factor of 2

Radiation Testing of Cameras at the Van de Graaff Accelerator Facility

18

IR camera OTR camera ZnSe window Quartz window Gold mirror Silver mirror Target

y = 20.154x + 0.357 R² = 0.9979 50 100 150 200 250 5 10 15 Radcal dose rate (R/h) Van de Graaff current (µA)

Dose rate at 113 inches

113 inches Linear (113 inches)

Radiation Testing of the Cameras

19

Testing at the Van de Graaff accelerator showed that cameras will survive more then a year in the facility

Molybdenum cycle

20

Disk production from Mo-100 powder Mo-99 production by (, n) reaction Target dissolution in H2O2 + KOH 0.2g-Mo/mL in 5M KOH in TechneGen generator Mo recycled from 5M KOH to form MoO3 and reduced to Mo

21

Mo recovery

Reagent Mo lost K removed Glacial AcA 0.2-2% 70-80% 70% HNO3 5-20% 80-90% Ethanol 0-0.2% ~40% AcA+ethanol (1:4) 0-0.2% ~40% H2SO4 N/A N/A H2SO4 - not suitable for Mo precipitation – forms Mo suspension HNO3 - not suitable for Mo precipitation – significant Mo loss Ethanol - not suitable for Mo precipitation – does not remove K from K2MoO4 Acetic acid – the best reagent – good removal of K, good Mo recovery

ppt

AcA + EtOH AcA 1mL of K2MoO4 in 5M KOH + 5mL of reagent (1:5 ratio)

22

Summary of the Mo recycle and future plans

• Mo can be precipitated from highly alkaline solution using glacial acetic acid
• Mo precipitate is then washed with 70% HNO3
• Good Mo recovery 97-100% obtained if 1st HNO3 wash allowed to sit for several

hours

• Purification of potassium <25 ppm (99.999% removed) – for small scale, work

continues with large scale experiments

• XRD characterization of Mo precipitate – converting to MoO3
• Large scale experiments look promising and able to process up to 400g of Mo
• HNO3 can be recycled
• Large scale experiments continue with dissolved irradiated targets
• Precipitation step and washing steps need to be optimized for better Mo recovery

Summary

23

• We have conducted several irradiation that demonstrated satisfactory target
• performance. Next tests will be focused on production of Mo-99.
• Simple beam-line design for production facility was developed and tested.
• MCNPX calculation for production-facility shielding showed that 30 cm of lead

and 250 cm of concrete will be sufficient for effective shielding both neutrons and photons.

• Substitution of Inconel by stainless steel in the target housing will reduce dose

by factor of two.

• Cameras testing at the Van de Graaff facility demonstrated sufficient radiation

resistance of the equipment.

• Mo recycle process was demonstrated with good efficiency.

Acknowledgements

24

• The submitted manuscript has been created by UChicago Argonne, LLC,

Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by

• r on behalf of the Government.
• Work supported by the U.S. Department of Energy, National Nuclear

Security Administration's (NNSA's) Office of Defense Nuclear Nonproliferation, under Contract DE-AC02-06CH11357.