Thorium, a fertile nuclear fuel which is nearly three times as abundant uranium, represents long-term energy resource that could complement uranium by making the current cycle more sustainable. With expected refurbishment and new construction of pressure-tube–heavy-water reactors (PT-HWRs) within international community, there good opportunity to gain experience with thorium-based fuels start transition phase toward use thorium part cycle. Previous studies have shown in near term (10 15...

Thorium, a fertile nuclear fuel that is nearly three times as abundant uranium, represents long-term energy source could complement uranium and eventually replace it. With the expected refurbishment new construction of pressure tube heavy water reactors (PT-HWRs) within international community, there an opportunity to gain experience with thorium-based fuels start transition toward use thorium part cycle.This paper presents evaluation types be implemented in near-term into current PT-HWRs....

Thorium, a fertile nuclear fuel that is nearly three times as abundant uranium, represents long-term energy source could complement uranium and eventually replace it. To facilitate the gradual transition from uranium-based fuels to thorium-based fuels, it may be advantageous in near term introduce small amounts of thorium (˂7% total mass) into pressure tube heavy water reactors (PT-HWRs). Downblending natural or slightly enriched dioxide with for pellets placed at ends stack conventional...

Lattice physics sensitivity studies have been performed with WIMS-AECL to quantify the impact of various design and operating parameters on performance characteristics thorium-based fuel concepts in pressure-tube heavy-water reactors. Fuels modeled included 37-element bundles natural uranium oxide (for comparison), pure thorium (blanket-type fuel) 35-element mixed U-233. Key evaluated lattice reactivity, exit burnup, coolant void reactivity (CVR), fissile concentration. The effects...

This study assesses the resource throughput and utilization of various thorium-based fuel concepts for near-term deployment in a pressure-tube heavy water reactor (PT-HWR). Such may be interest to nations with thorium reserves that are interested exploiting PT-HWRs. Given abundant relatively small uranium have an reducing their dependence on natural (NU) imports, assessed terms ability conserve resources impact national income using economic multiplier analysis. It is found there some...

Lattice physics and core studies have been carried out to investigate the reactor feasibility of destroying americium (Am) curium (Cm) using special target fuel bundles in blanket channels a heterogeneous seed-blanket pressure tube heavy water (PT-HWR) fueled primarily with natural uranium. Results indicate that it should be feasible achieve net-zero production Am single PT-HWR 10 16 dedicated containing Am-based while only one channel would required for achieving Cm. While use elements made...

The fueling unit energy cost of various thorium-based fuels and uranium-based augmented by small amounts thorium in a pressure tube heavy water reactor (PT-HWR) are assessed building upon previous studies. results suggests that fuel concepts using slightly enriched uranium mixed with low-enriched can be competitive have the greatest potential for near-term implementation PT-HWRs. Thorium-based contain recycled plutonium or 233U will require more effort to identify develop technologies reduce...

Lattice physics and core studies have been carried out to investigate the feasibility of destroying long-lived fission products (LLFPs) using special target fuel bundles in blanket channels a seed-blanket pressure tube heavy water reactor (PT-HWR) fueled primarily with natural uranium. Results indicate that it should be feasible achieve net zero production LLFPs such as 79Se 129I one two dedicated containing LLFP bundles. With 60 channels, rate 99Tc or 126Sn could reduced by 75% more....

The use of advanced uranium-based and thorium-based fuel bundles in a 700-MW(electric)–class pressure tube heavy water reactor (PT-HWR) has the potential for improved performance characteristics with higher burnup, fissile utilization, lower coolant void reactivity while also extracting energy thorium. In this study, thermal-hydraulic subchannel analyses were performed single, high-power (6.5 MW), 12-bundle channel at typical operating conditions 14 different PT-HWR lattice/core concepts...

This paper reports the results of subchannel thermal-hydraulic studies (using ASSERT-PV code) effects variations and uncertainties in operating/boundary conditions geometry on predictions pressure drop, dryout power, location for two types advanced, nonconventional fuels a tube heavy water reactor (PT-HWR) fuel channel with 12 bundles. The bundles tested include 37-element bundle made SEUO2 (1.2 wt% 235U/U), central element ThO2, 35-element (LEU,Th)O2, using 5 235U/U low-enriched uranium...

A computational benchmark, using the deterministic codes WIMS-AECL and WOBI, stochastic code SERPENT, is made for burnup calculations of advanced thorium fuels in heavy water moderated reactors. Exit burnups concentration longer-lived actinides from set which are 2-D, were compared to those a full 3-D calculation SERPENT. Results reactivity vs. time general agreement within few mk (<1% overall neutron multiplication) appear be systematic. exit larger, 3%–6% range, because small effects...

The use of advanced uranium-based and thorium-based fuel bundles in pressure tube heavy water reactors (PT-HWRs) has the potential to improve utilization uranium resources while also providing improvements performance safety characteristics PT-HWRs. Previous lattice physics core studies have demonstrated feasibility using such fuels; however, thermal-hydraulic (T-H) are required confirm that these fuels will adequate T-H margins. Preliminary system transient simulations been performed for a...

The use of advanced uranium-based and thorium-based fuel bundles in pressure tube heavy water reactors (PT-HWRs) has the potential to improve utilization uranium resources while also providing improvements performance safety characteristics PT-HWRs. Earlier lattice physics reactor core studies have demonstrated feasibility using such fuels; however, thermal-hydraulic (T-H) are required confirm that these fuels will adequate T-H margins. Preliminary system transient simulations been carried...