CONICET Digital Nro.11513

AnnalsofNuclearEnergy78(2015)10–14 ContentslistsavailableatScienceDirect Annals of Nuclear Energy journal homepage: www.elsevier.com/locate/anucene Feasibility study of a hybrid subcritical fission system driven by Plasma-Focus fusion neutrons Alejandro Claussea,⇑ , Leopoldo Sotob,c, Carlos Friedlib, Luis Altamiranod aCNEA-CONICETandUniversityofCentralBuenosAires,7000Tandil,Argentina bComisiónChilenadeEnergíaNuclear,Casilla188-D,Santiago,Chile cCenterforResearchandApplicationsinPlasmaPhysicsandPulsedPower,P4,Chile dDicontekLtda.,Santiago,Chile a r t i c l e i n f o a b s t r a c t Articlehistory: A feasibility analysis of a hybrid fusion–fission system consisting of a two-stage spherical subcritical Received13October2014 cascadedrivenbyaPlasmaFocusdeviceispresented.Theanalysisisbasedontheone-groupneutron Receivedinrevisedform24December2014 diffusionequation,whichwasappropriatelycasttoassesstheneutronicamplificationofasphericalcon- Accepted26December2014 figuration.Adesignchartwasproducedtoestimatetheoptimumdimensionsofthefissileshellsrequired toachievedifferentlevelsofneutronamplification.ItisfoundthatcascadesdrivenbyPlasmaFocusof tensofkJarefeasible.TheresultswerecorroboratedbymeansofMonteCarlocalculations. Keywords: (cid:2)2015ElsevierLtd.Allrightsreserved. Fusion–fissionhybrid PlasmaFocus Subcritical Breakeven Pulsedreactor 1.Introduction ADS(Nifeneckeretal.,2003).Inthelastdecadehasbeenarenewed interest in ADS systems, including experimental validations The concept of hybrid nuclear reactors combining fusion and (Shahbunder et al., 2010), comprehensive physical (Wang et al., fissionprocesseswasfirstproposedinthedecadeof1950(seeref- 2013) and economic analysis (Steer et al., 2012; Gulik and erencesinNifeneckeretal.,2003)andwasreactivatedlaterinthe Tkaczyk,2014).Veryrecentlythecommissioningofazeropower 70s(Bethe,1979).Afterthat,theinterestinthehybridideawaned, experimentalsubcriticalfacilityhasbeenreportedinIndia(Sinha not so much because of technical difficulties but for lack of etal.,2015).Also,basedonthetheoryofADSanisotopesourcedri- economic incentive. This remained so until the last two decades, vensubcriticalbatterywasproposed(WangandHe,2014). duringwhichtheinterestinhybridshasagainincreasedfortheir Itisgenerallyacceptedthatforsecurityandcontrolreasons,the possible application in energy production, either using Uranium effectivemultiplicationfactorofasubcriticaldrivensystemshould fuelorcombiningbreedersystemswithThoriumfuelcycles,and belimitedtoabout0.98forfast-neutronreactorsand0.95forther- also for the destruction of nuclear waste (Abalin et al., 1995; malreactors(Nifeneckeretal.,2003).Thislimitation,inprinciple, Gerstner, 2009; Freidberg and Kadak, 2009; Kotschenreuther imposes an upper bound to the amplification factor. In order to etal.,2009). increase the amplification without compromising the subcritical Thecentralconceptofhybridsistosurroundafusionsourceof condition,theconceptofcascadereactorswasintroducedasearly neutronswithfissilefuelconfiguredinsuchawaythatthewhole asthe50s(Borst,1957;Avery,1958;Dubovskii,1959)andreacti- systemissubcritical.Theneutronsinjectedbythesource,usually vated in the 90s by Daniel and Petrov (1996) and Barzilov et al. as a train of pulses, are then multiplied by fissions, generating a (1996).Recently,controlandsafetyissuesofspecificcascadecon- total energy that in principle should be larger than the input figurationswereanalyzedusingMonteCarlomethods,inspherical energyrequiredforthefusionprocess.Themostpopularneutron (Kolesov and Khoruzhii, 2003) and cylindrical geometries drivers that were proposed are spallation targets pumped by (Gulevich et al., 2007). Essentially a cascade or diode subcritical protonorelectronaccelerators,calledAcceleratorDrivenSystems, reactor consists of two multiplying sections (generally separated spatially)withasymmetriccoupling,insuchawaythatneutrons ⇑ produced in the first section easily penetrate the second while Correspondingauthor.Tel./fax:+542494385690. thoseproducedinthesecondhavelittleinfluenceoverthefirst. E-mailaddress:[email protected](A.Clausse). http://dx.doi.org/10.1016/j.anucene.2014.12.028 0306-4549/(cid:2)2015ElsevierLtd.Allrightsreserved.