Radiation Effects and Nuclear Power - Royal …

1 Radiation Effects and Nuclear PowerSimon M. PimblottSchool of Chemistry, Univ. of ManchesterDalton Nuclear InstituteRadiation Effects are important in: Waste remediation and management Spent fuel reprocessing Deep geological disposal Continued generation Naval propulsion Next generation new build Advanced reactors & fuel cyclesWaste Tanks& PondsPu & Spent Fuel DispositionNew Fuels eactor Unit Recuperators Compressors TurbineInter cooler Pre coolerGearboxGeneratorNext Generation Nuclear PlantAim: To develop a mechanistic understanding of performance deterioration and chemical degradation to allow a predictive description of Radiation -induced Effects and usage lifetime. Interfacial water-oxide-metal process Heterogeneous systems Humid and damp systems Hydrocarbons and organic polymers Chlorinated polymers & materialsFundamental Underpinning ResearchRadiation Effects andGeological DisposalSimon M.

2 PimblottSchool of Chemistry, Univ. of ManchesterDalton Nuclear InstituteJournal of Nuclear Materials 346 (2005) 66 77 Christophe Poinssot et al. radiationPu / radiationHeterogeneousmixed-phasesystems WaterOxideparticlesMixed radiationfieldsPolymersRadioactivedecay2 41 radiationRadiation-Induced Chemistry / radiationHeterogeneousmixed-phasesystems WaterMixed radiationfieldsPolymersH2 Radiation -Induced ChemistryHClHeterogeneousmixed-phasesyst emsWaterOrganic liquidsPolymersResearch Projects for 2009-2010 Radiolytic off-gassing of organics in aqueous environments. (NNL, NDRL) GSRadiolytic degradation of PVC. (NNL, NDRL) GSEffects of mixed Radiation fields. (NDRL)Radiolysis of water in zeolites. (CEA) $EU-LaserlabAqueous Radiation chemistry of U(IV). (CEA, NDRL) Radiation damage to biopolymers and biosystems.(PSI, Univ. of Rochester) PDH2production in the irradiation of water in contact with oxide particles.

3 (NNL, NDRL) GS $EPSRCI mpact of Radiation on microbial cells.(SEAS) GS $BBSRC $NDAR adiations chemistry of extremely alkaline systems. (NNL, NDRL) GS Radiolytic degradation of silicones. (UKAEA, NDRL) $NDA-DRPP olymeric Materials in Nuclear EnvironmentsAim: To understand and quantify performance deterioration and chemical degradation to allow a predictive description of Radiation -induced Effects and usage Degradation of PVCP olymers are found throughout the Nuclear portfolio. Nuclear waste materials Encapsulants Nuclear InfrastructureQuestions about Perfomances Degradation Off-gasing Non-aqueous phase liquid formationEffects due to Aging Local environment Radiation fieldsUnderstanding Performance of Irradiated Polymers: What Does This Involve? Radiation track structure simulationPolymer behaviourperformanceChemical degradationab initiotheoryExperiments with ionizing radiationReaction dynamics theoryPhoton scienceexperimentsMechanicalstressorsMol ecular Dynamics( CH2 CHCl )nThermoplastic polymer, rigid materialImportant physical properties: flexibility, softness, transparency Additives (plasticisers and stabilisers)Applications in Nuclear industry- PVC insulation and jacketing materials - radioactive waste packaging materialConcerns:hazardous compounds released !

4 ApplicationsPolyvinylchloride (PVC) Polychloroethene (IUPAC) Effects of ionizing Radiation on PVCC urrent Status Significant componenet of Nuclear waste management portfolio. Post-irradiation degradation of PVC physical and chemical changes. Main products defined, but Mechanisms poorly understood and inadequately approach to understand and elucidate the Effects of Radiation (alpha, beta, gamma or n) on PVC in different environments (i. e. the presence of over-gases, humidity, hydrocarbons, ceramic particles etc.).Experimental work at Univ of Notre Dame (USA) with complementary work at the Central Laboratory of NNL involving plutonium contaminated PVC. -Radiolysis Shepherd 109-68 60Co source, self-contained dose rate of ~ kRads min-1(83 Gy min-1). Irradiation: room temperature, h (10 kGy) and 12 h (50 kGy). 4He-RadiolysisPVC powder, no additivesUPVC film FN Tandem Van de Graaff facility of the University of Notre Dame Nuclear Structure Laboratory.

5 Irradiation: with completely stripped ions, charge beam current ~ , room SamplesExperimentsRadiation Quality10-410-310-210-110010110210010110 2103104105S (MeV cm2 / g)Energy (MeV) e- 1H+ 2D+ 4He2+ 12C6+slide 7 of 19 Chromatography Gas chromatography (GC) Ion chromatography (IC)Spectroscopy UV/VIS absorbance FT-IR transmission EPR Experimental techniquesExperimental Setup: Gamma RadiolysisCellGCGamma source (60Co)Mass spectrometerExperimental Setup: Ion Beam RadiolysisCellGCMass spectrometerHeavy ion beam lineRadiation induced degradation of chlorinated polymersOff-gasing of corrosive HCl and H2from PVC Yields and post-irradiation behaviourStructural degradation of irradiated PVC Change in molecular weight and distribution of polymer chain lengths Formation of conjugated C=C systems Oxidation and production of C=O chromophoresChemical evolution of irradiated polymer Long term survival of radicalsRadiation-induced H2 ProductionMn(Dalton) ( ) ( )De-aerated22 & Aerated22 - from PVC-H2O SystemsRadiation-induced HCl ProductionMn(Dalton) ( ) ( )Wet & aerated22 & aerated47 & aerated99 -rays powder 4 m diameter film 1mm x 2mm x 10mm10 kGy50 kGyCl- ( mole/g)Postradiolysis Time (hour)

6 Post Irradiation Release of HClRadiation induced degradation of chlorinated polymersOff-gasing of corrosive HCl and H2from PVC Yields and post-irradiation behaviourStructural degradation of irradiated PVC Change in molecular weight and distribution of polymer chain lengths Formation of conjugated C=C systems Oxidation and production of C=O chromophoresChemical evolution of irradiated polymer Long term survival of radicalsslide 10 of 19blank10 kGy20 kGy50 kGy100 kGy PVC degrades with formation of observable chromophores free radicals, conjugated double bonds, carbonyl groups, etc. Extent of discolouration depends on applied dose, irradiation environment and post-irradiation powder,10 kGy ( )22k PVC powder,10 kGy ( , vacuo)UPVC film10 kGy ( )Colour (nm)Uv-vis Spectroscopy of Radiation -induced Degradation of PVCPost Irradiation Evolution061218243036424801234 AbsorbanceTime (hr)IR Spectroscopy of Radiation -inducedDegradation of PVCE ffect of sat.

7 C-HOH (in COOH)CO2(?)CH2(m)C=C (in dienes/trienes)C-ClC=OTransmittanceWavel ength (cm-1) 1h 10h 24hIR Spectroscopy of Radiation -induced Degradation of PVCPost Irradiation EvolutionRadiation induced degradation of chlorinated polymersOff-gasing of corrosive HCl and H2from PVC Yields and post-irradiation behaviourStructural degradation of irradiated PVC Change in molecular weight and distribution of polymer chain lengths Formation of conjugated C=C systems Oxidation and production of C=O chromophoresChemical evolution of irradiated polymer Long term survival of radicalsVariations with time ( hr) of the EPR spectrum of -irradiated in air 22k PVC powder (50 kGy). 010 3040506010-1100 Peak HeightPost-irradiation Time (hr) Peak 1 Peak 2 Peak 3 Peak 4 Spectrum of multiple overlapping signals with two observable components: fast decay of primary radicals and slow decay of long-lived peroxyl 4 Peak 3 Peak 2 Peak 1 [hr] 2 3 5 7 25 36 53 Intensity ( )Magnetic field (G)EPR spectroscopy3400342034403460348035003520 -2000-1500-1000-5000500100015002000 Intensity ( )Magnetic field (G)010 3040506010-1100 Peak HeightTime (hr) Peak1 Peak2 Peak3' Peak4'Variation with time (0-26 hr) of the EPR spectra of 22k PVC powder, -irradiated in vacuo to 10 kGy.

8 8x10-19x10-1100 Peak HeightPost-irradiation Time (hr) Peak 1 Peak 2 Peak 3 Peak 4 Polyenyl radical(s) can be very stable under vacuo. 34203450348035103540-1500-1000-500050010 0015002000 Peak 4 Peak 3 Peak 2 Peak 1Si O2 Intensity ( )Magnetic field (G) [hr] 2 3 5 7 26 EPR spectroscopyInitiation reaction:C-Cl reactions:HCl evolution (free radical mechanism)Formation of H2from H atom precursorsRadical reactions (propagation):Reaction MechanismsReaction MechanismsPredictive (Modeling) CapabilityEnergy transfer from radiationRadiation-induced ionizationFragmentation, thermalizationand solvationSpatially nonhomogeneous distribution of reactantsDiffusion-limited chemistryObserved effectsModelling of polymer degradationPrediction of physical performance chemical reactivity of hydrocarbon and chlorinated hydrocarbon polymers under psZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 01 nsZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 010 nsZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 0100 nsZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 01 psZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 01 sZ Axis (nm)Y Axis (nm)X Axis (nm)

9 -100-50050100-50050100150-50050100150 Primary trackZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 0 Secondary tracksZ Axis (nm)Y Axis (nm)X Axis (nm)-100-50050100-50050100150-5005010015 0 Low energy electronsZ Axis (nm)Y Axis (nm)X Axis (nm)Development of a 10 keV section of a 5 MeV 4He2+ion track in water Complete description of physical and chemical evolution of Radiation trackResearch FundingAcknowledgementsSchool of ChemistryUniversity of ManchesterAshley BrownRafal FeligaMatthew HancockMonica HuertaLaura NunnsPaul KaufmanPavlina PavlovaStephenie PalmerAshley RichardsonMikko RieseOxford UniversityNick GreenRadiation Laboratory University of Notre DameM. Soledad AraosEduardo A. Carrasco-FloresMaria DavidkovaRowan HenryBratoljub H. MilosavljevicaTingting MuBarbara PastinaPuspalata RajeshNNLH oward E. Simsand especially The lack of fundamental data for the most important chemical species is the single largest factor limiting the successful application.

10 To problems of industrial interest NAS Report on Database Needs