Simulation of absorbed doses distribution in a polyethylene phantom for BNCT application at the Dalat research reactor

In this paper, the distribution of absorbed dose components in a polyethylene phantom for BNCT application at Dalat Nuclear Research Reactor (DNRR) were calculated using the MCNP5 code. The configuration of horizontal neutron channel No.2 of the DNRR, which contains a cylindrical collimator with neutron filters of 20-cm Si and 3-cm Bi, was simulated. The results show that the gamma dose along the central axis of the phantom has the maximum value of 1.82×10-6 Gy at the 0.5-cm depth, and reduces to 9.05×10-7 Gy at the 3-cm depth. The main contribution to gamma dose is due to the interaction of thermal neutron with hydrogen in the phantom via the 1H(n,γ)2H reaction, and its value is much smaller than thermal neutron dose. The total absorbed dose along the central axis of the phantom has the maximum value of 7.87×10-5 Gy at the 0.5-cm depth, and decreases rapidly to 1.52×10-5 Gy at the 3-cm position, and mainly depends on the boron and thermal neutron doses caused by the 10B(n, α)7Li and 14N(n, p)14C reactions, respectively.

Study on the production of ¹⁷⁷Lu for medical purposes at the Dalat Research Reactor. Part 1. Study on production of ¹⁷⁷Lu at the Dalat Research Reactor

Lutetium-177 (177Lu) radioisotope used for medical purposes has been produced at the Dalat Nuclear Research Reactor during 2012-2014. The product was synthezed by the activation reaction 176Lu (n,γ) 177Lu. The target was Lutetium oxide with an abundance of 176Lu being 2.59% and the irradiation was conducted with a neutron flux of 2.1013 n cm-2 s-1. The activity of the 177Lu product was 39,59 Ci g-1 after 108 hous of the irradiation. The yield of this method was much higher compared to those of the reaction 176Yb(n, γ)177Yb → 177Lu + β- which for the same time could be 15mCi/50mg only. Because of low specific radioactivity the preparation of 177Lu made from the activation of 176Yb cannot be applied for the medical purposes. Additionally, the separation yield of 177Lu from 177Yb is rather low, it is usualy of approximately 70%.

Some Main Results of Commissioning of The Dalat Research Reactor with Low Enriched Fuel

After completion of design calculation of the Dalat Nuclear Research Reactor (DNRR) for conversion from high-enriched uranium fuel (HEU) to low-enriched uranium (LEU) fuel, the commissioning programme for DNRR with entire core loaded with LEU fuel was successfully carried out from 24 November 2011 to 13 January 2012. The experimental results obtained during the implementation of commissioning programme showed a good agreement with design calculations and affirmed that the DNRR with LEU core have met all safety and exploiting requirements.