Recent advances in the design of a cyclotron-driven intense, subcritical neutron source

The authors recently proposed a subcritical, cyclotron-based spallation neutron source, with neutron multiplication by fission. The present paper presents some recent advances in the design of this system, together with the design corresponding to the optimal configuration for /sup 99/Mo production.Anglai

Simulations of Progressive Potential Scenarios of Pu Multirecycling in SFR and Associated Phase-out in the French Nuclear Power Fleet

International audienceAfter the studies carried out in the frame of the 2006 French Act for waste management, the CEA, EDF and AREVA decided to work together on progressive potential scenarios of the French transition between the current nuclear fleet and a SFR fleet which does not require natural uranium to operate. To do so, several steps were defined, each of them having a different purpose and allowing a gain of experience to move on to the next one.In one of these scenarios, between 2030 and 2062 the current PWR fleet is renewed by an EPR reactor fleet in which plutonium keeps on being monorecycled. This EPR reactor fleet is loaded with about 10% of MOX fuel which enables to stabilize the UOX spent fuel inventory. Beginning from the 2040 decade, a few FR reactors and their associated cycle are progressively introduced MOX PWR spent fuels reprocessing begins in 2040 in order to feed three 1000 MWe breakeven SFR, commissioned between 2050 and 2059.This enables to test at an industrial scale the new Nuclear System and to stabilize used MOX fuel inventory. To prepare for a larger FR deployment, three 1450 MWe breakeven SFR are commissioned between 2075 and 2085. An SFR spent fuel reprocessing of 15 to 21 tHM/y starts in 2060 in order to feed the three 1450 MWe SFR. From 2090, thirteen additional 1450 MWe SFR are deployed in order to reach an equilibrium fleet composed of sixteen 1450 MWe breeder SFR and 22 EPR reactors (with an average MOX load of 39.5%). At this point of the scenario, the Pu global inventory is stabilized, and the energy production remains constant at 420TWhe. From 2150, this EPR/SFR reactor fleet is progressively renewed by a new one composed of 41 breakeven SFR, which does not require natural uranium to operate.SFR deployment in 2150 leads to a slight increase in the global plutonium inventory which stabilizes definitively in 2180. At the end of the scenario, the Pu inventory is reduced by 47% compared with a 100% UOX PWR fleet (open cycle scenario). The global minor actinides inventory is increasing at a rate that can be managed at the back end. Over the whole scenario, 1.01.106 tons of natural uranium have been used. This represents a 40% reduction compared with the open cycle scenario.A faster SFR deployment scenario was also studied, identical to the previous one up to 2090. From 2090, a 41 SFR fleet is deployed according to Pu availability. The equilibrium is reached in 2135 when the global Pu inventory is stabilized.Nuclear phase-outs have been studied at several dates in order to evaluate the impacts in terms of inventories at each step of the scenario. Studies of optimized phase-out, aiming at reducing the Pu global inventory, the spent fuel mass and the waste inventories, have also been carried out. They involve MOX EPR reactors with high moderation ratio and enriched uranium support and burner SFR

Review of Recent Advances in Heating and Current Drive on Textor

Co-injection (DO --> D+) applied to TEXTOR leads to a hot ion node regime with enhanced confinement. A synergistic increase of the beam effects is observed with the addition of ICRH at omega = 2omega(cD) = omega(cH) (H minority heating scenario) resulting, beside other reviewed effects, in a significant increase of the ion temperature and of the beam driven current (respectively larger than 30 % and 50 % for the addition of an RF power comparable to the NBI one). The large ion heating efficiency of ICRH also remains when ICRH is added to balanced injection and the hot ion mode regime remains up to the maximum achieved beta (=2/3 of the Troyan limit with more than 6MW of auxiliary heating). ICRH also leads to the formation of a more \u27isotropic\u27 tail. These results are interpreted with the help of a Fokker-Planck code which computes the beam distribution function in presence of RF and of TRANSP simulations. The amount of RF absorption by the H minority by the ion beam and die bulk plasma is theoretically evaluated. It is shown that a large part of the synergistic effects can be explained by the rise of the electron temperature due to the minority heating which increases the beam slowing down time and its critical energy. A smaller contribution to the effects is due to direct coupling of the RF power to the beam (less than 10 % of the total RF absorbed power) and to the decrease of the plasma toroidal rotation induced by the RF. ICRH has also been added to co-injection at omega = 3omega(CD). In this case no minority heating is present and the RF energy coupling to the beam is one of the dominant effects. It leads to the formation of a very energetic tail of the ion beam with a strong increase of the beam-target neutron reactivity

PUMA - Plutonium and Minor Actinides management in thermal high-temperature reactors

none18mixedJ.C. Kuijper; J. Cetnar; S. Shihab; G. Toury; N. Cerullo; G. Lomonaco; E. Girardi; F. Venneri; W. Bernnat; J. Somers; J. Wallenius; L. Van Den Durpel; T. Abram; D. Millington; V. Chauvet; J. L. Kloosterman; H. Werner; C. TrakasJ. C., Kuijper; J., Cetnar; S., Shihab; G., Toury; Cerullo, Nicola; Lomonaco, Guglielmo; E., Girardi; F., Venneri; W., Bernnat; J., Somers; J., Wallenius; L., Van Den Durpel; T., Abram; D., Millington; V., Chauvet; J. L., Kloosterman; H., Werner; C., Traka

PU and MA Management in Thermal HTGRs \u2013 Impact at Fuel, Reactor and Fuel Cycle levels.

The PUMA project, a Specific Targeted Research Project (STREP) of the European Union EURATOM 6th Framework Program, is mainly aimed at providing additional key elements for the utilisation and transmutation of plutonium and minor actinides (neptunium and americium) in contemporary and future (high temperature) gas-cooled reactor design, which are promising tools for improving the sustainability of the nuclear fuel cycle. PUMA would also contribute to the reduction of Pu and MA stockpiles and to the development of safe and sustainable reactors for CO2-free energy generation. The project runs from September 1, 2006 until August 31, 2009. PUMA also contributes to technological goals of the Generation IV International Forum. It contributes to developing and maintaining the competence in reactor technology in the EU and addresses European stakeholders on key issues for the future of nuclear energy in the EU. An overview is presented of the status of the project at mid-term