Estimation of 99Mo production rates from natural molybdenum in research reactors

Abstract

Molybdenum-99 is one of the most important radionuclides for medical diagnostics. In 2015, the International Atomic Energy Agency organized a round-robin exercise where the participants measured and calculated specific saturation activities achievable for the 98 Mo(n,c) 99 Mo reaction. This reaction is of interest as a means to locally, and on a small scale, produce 99 Mo from natural molybdenum. The current paper summarises a set of experimental results and reviews the methodology for calculating the corresponding saturation activities. Activation by epithermal neutrons and also epithermal neutron self-shielding are found to be of high importance in this case.

Molybdenum-99 production pathways and the sorbents for 99Mo/99mTc generator systems using (n, γ) 99Mo: a review

“…In this process, 99 Mo is produced by the irradiation of molybdenum ( 98 Mo) in a thermal neutron flux, { 98 Mo(n,γ) 99 Mo}. The thermal (~ 0.025 eV) or epithermal (0.025-1.0 eV) neutrons produced by the fission of uranium in a nuclear reactor can be used to generate 99 Mo radionuclide by bombarding stable 98 Mo target material placed in the reactor [17,18]. In this process, the 98 Mo nuclei capture neutron and transform into 99 Mo isotope as shown in Fig.…”

“…Several studies investigated the thermal and resonance neutrons input into the 99 Mo activation process. [16,17,21]. Ryabchikov et al [21] reported that the resonance part of the neutron spectra enhance the yield of 99 Mo significantly by increasing the effective cross-section of 98 Mo(n, γ) 99 Mo reaction from 0.14b to 0.7b.…”

“…Toth et al [22] reported that there are several factors such as self-shielding, parasitic absorption, and depletion of the product that must be accounted to identify the effective cross-section as these factors may change the results by 10 to 50%. Blaauw et al [17] reported that the careful estimation of the epithermal neutron contribution and neutron self-shielding correction can provide specific saturation activity of 99 Mo with good accuracy for the 98 Mo(n, γ) 99 Mo reaction. It is reported that the use of enriched Mo has a minor effect of the activation rate through the self-shielding of epithermal neutron by the other Mo isotopes [17,21].…”

Development of Novel Alumina by Solid-State Reaction for 99Mo/99mTc Adsorbent Material

“…The alternative routes can be classified as neutron activation of natural molybdenum using research reactor and irradiation of high enriched molybdenum using cyclotron. The first method is mainly developed in developing countries possessing a research reactor without proper fission- 99 Mo production facility (Blaauw et al, 2017;M Munir et al, 2019). The second method is mainly carried out in developed countries possessing a proper cyclotron for 99 Mo production.…”

Influence Of Drying Time And Temperature On Zirconium-Based Material (ZBM) Properties For 99Mo/99mTc Generator Development

“…The advantages of nonfission 99 Mo compared to fission 99 Mo are the easy handling of the waste, the low radioactivity waste, and the simple post-irradiation method. On the other hand, the drawback is the low specific activity compared to fission 99 Mo (Blaauw et al 2017;Marlina et al 2017).…”