Abstract: One of the main characteristics of Heavy Water Moderated Reactors is their high production of plutonium. This article demonstrates the possibility of reduction of plutonium and other actinides in Heavy Water Research Reactor. Among the many ways for reducing plutonium production in a heavy water reactor, in this research, changing the fuel from natural Uranium fuel to Thorium-Uranium mixed fuel was focused. The main fissile nucleus in Thorium-Uranium fuels is U-233 which would be produced after neutron absorption by Th-232, so the Thorium-Uranium fuels have some known advantages compared to the Uranium fuels. Due to this fact, four Thorium-Uranium fuels with different compositions ratios were chosen in our simulations; a) 10% UO2-90% THO2 (enriched= 20%); b) 15% UO2-85% THO2 (enriched= 10%); c) 30% UO2-70% THO2 (enriched= 5%); d) 35% UO2-65% THO2 (enriched= 3.7%). The natural Uranium Oxide (UO2) is considered as the reference fuel, in other words all of the calculated data are compared with the related data from Uranium fuel. Neutronic parameters were calculated and used as the comparison parameters. All calculations were performed by Monte Carol (MCNPX2.6) steady state reaction rate calculation linked to a deterministic depletion calculation (CINDER90). The obtained computational data showed that Thorium-Uranium fuels with four different fissile compositions ratios can satisfy the safety and operating requirements for Heavy Water Research Reactor. Furthermore, Thorium-Uranium fuels have a very good proliferation resistance and consume less fissile material than uranium fuels at the same reactor operation time. Using mixed Thorium-Uranium fuels reduced the long-lived α emitter, high radiotoxic wastes and the radio toxicity level of spent fuel.
Abstract: Climate warming would increase rainfall by shifting
precipitation falling form from snow to rain, and would accelerate
snow cover disappearing by increasing snowpack. Using temperature
and precipitation data in the temperature-index snowmelt model, we
evaluated variability of snowfall and continuous snow cover duration
(CSCD) during 1944-2010 over Pelso, central Finland. Mann-
Kendall non-parametric test determined that annual precipitation
increased by 2.69 (mm/year, p
Abstract: Today, node-disjoint routing becomes inessential
technique in communication of packets among various nodes in
networks. Meanwhile AODV (Ad Hoc On-demand Multipath
Distance Vector) creates single-path route between a pair of source
and destination nodes. Some researches has done so far to make
multipath node-disjoint routing based on AODV protocol. But
however their overhead and end-to-end delay are relatively high,
while the detail of their code is not available too. This paper proposes
a new approach of multipath node-disjoint routing based on AODV
protocol. Then the algorithm of analytical model is presented. The
extensive results of this algorithm will be presented in the next paper.
Abstract: an intelligent BRT system is necessary when
communities looking for new ways to use high capacity rapid transit
at a reduced cost.This paper will describe the intelligent control
system that works with Datacenter. With the help of GPS system, the
data center can monitor the situation of each bus and bus station.
Through RFID technology, bus station and traffic light can transfer
data with bus and by Wimax communication technology all of parts
can talk together; data center learns all information about the location
of bus, the arrival of bus in each station and the number of passengers
in station and bus.Finally, the paper presents the case study of those
theories in Tehran BRT.