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Title: Beam line shielding calculations for an Electron Accelerator Mo-99 production facility

Abstract

The purpose of this study is to evaluate the photon and neutron fields in and around the latest beam line design for the Mo-99 production facility. The radiation dose to the beam line components (quadrupoles, dipoles, beam stops and the linear accelerator) are calculated in the present report. The beam line design assumes placement of two cameras: infra red (IR) and optical transition radiation (OTR) for continuous monitoring of the beam spot on target during irradiation. The cameras will be placed off the beam axis offset in vertical direction. We explored typical shielding arrangements for the cameras and report the resulting neutron and photon dose fields.

Authors:
 [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
OSTI Identifier:
1253499
Report Number(s):
LA-UR-16-23092
TRN: US1601380
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 61 RADIATION PROTECTION AND DOSIMETRY; 43 PARTICLE ACCELERATORS; MOLYBDENUM 99; LINEAR ACCELERATORS; NEUTRONS; RADIATION DOSES; ELECTRONS; PHOTONS; TRANSITION RADIATION; BEAMS; CAMERAS; SHIELDING; DESIGN; DIPOLES; QUADRUPOLES; INFRARED RADIATION; MONITORING; RADIOISOTOPE GENERATORS; BEAM FOCUSING MAGNETS; BEAM TRANSPORT; BEAM DUMPS; CONFIGURATION; Accelerator Design; Technology; and Operations; Mo-99 production; neutron and photon dose

Citation Formats

Mocko, Michal. Beam line shielding calculations for an Electron Accelerator Mo-99 production facility. United States: N. p., 2016. Web. doi:10.2172/1253499.
Mocko, Michal. Beam line shielding calculations for an Electron Accelerator Mo-99 production facility. United States. doi:10.2172/1253499.
Mocko, Michal. Tue . "Beam line shielding calculations for an Electron Accelerator Mo-99 production facility". United States. doi:10.2172/1253499. https://www.osti.gov/servlets/purl/1253499.
@article{osti_1253499,
title = {Beam line shielding calculations for an Electron Accelerator Mo-99 production facility},
author = {Mocko, Michal},
abstractNote = {The purpose of this study is to evaluate the photon and neutron fields in and around the latest beam line design for the Mo-99 production facility. The radiation dose to the beam line components (quadrupoles, dipoles, beam stops and the linear accelerator) are calculated in the present report. The beam line design assumes placement of two cameras: infra red (IR) and optical transition radiation (OTR) for continuous monitoring of the beam spot on target during irradiation. The cameras will be placed off the beam axis offset in vertical direction. We explored typical shielding arrangements for the cameras and report the resulting neutron and photon dose fields.},
doi = {10.2172/1253499},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 03 00:00:00 EDT 2016},
month = {Tue May 03 00:00:00 EDT 2016}
}

Technical Report:

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  • Technetium-99m is a widely used radiopharmaceutical. Its parent, Mo-99, is produced worldwide to supply this important isotope. One means to produce Mo-99 is by bombarding a Mo-100 target with an electron beam from a linear accelerator; the γ/n reaction on Mo-100 produces Mo-99. After dissolving Mo-100 enriched disks in hydrogen peroxide, the solution is converted to potassium molybdate (0.2 g-Mo/mL) in 5 M KOH. After milking the Tc-99m in the TechneGen generator over a period of 7-10 days, the molybdenum solution needs to be treated to recover valuable Mo-100 for production of sintered Mo disks. However, during the production ofmore » Mo-99 by (γ, n) reaction on the Mo-100 target, several byproducts are formed. Therefore, recycling Mo will require the conversion of K 2MoO 4 in 5 M KOH solution to MoO 3 powder, and purification from other metals present in the Mo solution. The starting Mo-100 enriched material contains less than 20 mg of potassium in 1 kg of molybdenum (<20 ppm). However, after dissolving the irradiated Mo-100 target in hydrogen peroxide and converting it to K 2MoO 4 in 5 M KOH (0.2 g-Mo/mL), the solution contains about 1.8 kg of potassium per kilogram of molybdenum. The most challenging separation for this recovery step is purifying molybdenum from potassium. One requirement to facilitate the acceptance of the recycled material by the U.S. Food and Drug Administration (FDA) is that the impurities in the recycled material need to be at or below the levels present in the starting material. Therefore, the amount of potassium (K) in purified MoO 3 powder should be below 20 ppm; this will require a decontamination factor for removal of K to be ~1 × 10 5. Such a low K-contamination level will also prevent the production of large amounts of K-42 during irradiation of Mo-100. Based on economic concerns (due to the significant cost of enriched Mo-100) recycling Mo requires the conversion of K 2MoO 4 in a 5 M KOH solution to MoO 3 powder with high Mo recovery yields (>98%).« less