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Moreover, plutonium recycling and multi-recycling have been the subject of many studies. However, to reduce the radiotoxic inventory, it has been emphasised that any Pu multi-recycling strategy (whatever the aim of the strategy: Pu consumption, inventory stabilisation, etc.) must consider the essential goal of not increasing the production of minor actinides. Theoretically, the advantage of FRs (associated with lower σ c /σ f ratios in this type of spectrum) was illustrated in the physical approach described in the previous chapter. According to present views and insights, a scenario with simultaneous management of plutonium and MAs seems possible in order to achieve equilibrium between production and consumption of Pu, Am, Np and Cm within the reactors. The source term of the radiotoxic inventory generated by these reactors would be significantly reduced. The overall losses in the different reprocessing and partitioning operations would represent the minimum radiotoxic inventory of the waste resulting from the nuclear electricity generation. Several reactor park compositions with balanced reactor types can be considered. Figure II.24 shows a few examples. Figure II.24 Reactor park compositions PWR UOX Pu MA PWR MOX PWR UOX Pu MA FNR Pu + MA Pu + MA THERM MIX1 PWR UO 2 Pu PWR MOX Pu MA FNR FNR Pu + MA Pu + MA MIX2 FAST THERM MIX 1 MIX 2 FAST Reactor system consisting exclusively of PWRs, some of which are used for the multi-recycling of Pu and MAs. A similar system, but the actinide multi-recycling function is performed by CAPRA type FRs. A mixed system in which the Pu produced by PWR UO 2 is recycled once in PWR MOX. The residual Pu and all the MAs are recycled to CAPRA type FRs. A reactor system consisting exclusively of EFR-type FRs. 200
Since these reactor systems all have the same installed capacity, they are said to be in equilibrium in two respects: • the characteristics of these systems (proportions of the different reactors, actinide contents etc.) are determined so that equilibrium exists between actinide production and consumption. In the reactors, the actinide inventory remains unchanged. Only the losses in the different cycle operations (fabrication, reprocessing) represent the ultimate wastes intended for disposal; • since the PWR MOX and FBuR incinerator reactors cannot consume all the actinides loaded in a single passage, this obviously implies a change in the isotopic composition of the fuel during multi-recycling. To avoid drawing hasty conclusions from the results obtained in the first recyclings alone, the calculations are iterated until isotopic equilibrium in the fuel is obtained. Isotopic equilibrium is reached after about five to six cycles, and considering the inter-cycle times (cooling, reprocessing, fabrication), this corresponds to at least 50-70 years depending on the intercycle cooling time. Nevertheless, it must be emphasised that mass equilibrium between actinide production and consumption is always achieved in the first 5 cycles and before isotopic equilibrium is reached. The reactor system consisting exclusively of PWRs (THERM) has the following features: • in PWRs, it is not possible to recycle the MAs by mixing them only with Pu in MOX assemblies, because this would mean prohibitive Pu contents after the second recycle; • the recycling of MAs must be therefore dissociated from that of Pu, with some of the PWR reactors recycling Pu in MOX and others dedicated to recycling the MAs. This scenario still needs further examination; • in HMRs, the only possibility of jointly recycling Pu and MAs is to use an enriched U support while maintaining a constant Pu+MAs content. By way of example, with a Pu+MA content of about 8.4%, the masses of recycled Pu and MAs would theoretically be stabilised after twenty recycles. With a 55% HMR in the reactors, these masses would be around 962.5 t Pu and 245 t MAs, corresponding to annual flows of 78.75 t Pu and 19.25 t MAs in a system producing 700 TWhe/year. The characteristics of the other types of reactor system considered are as follows: • all the PWRs and FRs have an electrical capacity of 1 450 MWe. The burn-up of PWR UO 2 is 55 GWd/tHM. • for the MIX 1 and MIX 2 scenarios, the FR cores correspond to the CAPRA reference oxide, with initial enrichment of 45% and core residence time of 855 EFPD. • for the FAST scenario, the cores correspond to the reference EFR with zero regeneration gain (configuration with two axial blankets of 5 cm and one ring of radial fertile assemblies), with initial enrichment of about 20% and core residence time of 1 700 EFPD. Neptunium is recycled homogeneously and mixed with the fuel in the core. Americium is recycled heterogeneously in the form of targets placed in the first peripheral ring of the core. 201
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TABLE OF CONTENTS EXECUTIVE SUMMARY
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TABLE DES MATIÈRES NOTE DE SYNTHÈ
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PART II. TECHNICAL ANALYSIS AND SYS
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4. IMPACT OF P&T ON RISK ASSESSMENT
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Figure II.31 Evolution of the expec
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Part II: Technical analysis and sys
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There are several scenarios which c
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eactor concepts are still in the co
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intermediate storage management, th
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1. INTRODUCTION 1.1 Involvement of
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and natural decay play an important
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Figure I.2 A schematic diagram of b
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Instead of recycling, one could ado
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to address there is the separation
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improvement of the biological shiel
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Figure I.3 A schematic diagram of t
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Figure1.5 A notional materials flow
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A few specific regulatory and safet
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• irradiation of FR-fuel in Fast
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dispersion in the geosphere or bios
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In the meantime the burn-up of spen
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Any reprocessing campaign of spent
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4. CRITICAL EVALUATION • P&T may
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5. GENERAL CONCLUSIONS • Fundamen
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NOTE DE SYNTHÈSE ET PORTÉE DU RAP
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Présentation générale Cette part
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courts. L’application de cette te
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éalisable, à condition d’augmen
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PREMIÈRE PARTIE : PRÉSENTATION G
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La troisième réunion internationa
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1.5 Objectifs du rapport Dans l’e
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Figure I.1 Schéma de principe du c
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• l ’241 Am est le précurseur
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plutonium et environ 2 m 3 de déch
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2.3 Technologie de fabrication des
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cadre de la coopération EFTTRA ont
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On peut voir sur la Figure I.4 les
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Figure I.4 Flux de matières dans u
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À court terme, les produits de fis
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Par conséquent, au cas où l’on
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De nombreux laboratoires dans le mo
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usé devrait représenter environ 3
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le nucléide le plus gênant est le
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transuraniens. Pour obtenir un taux
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On peut considérer des opérations
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devrait en principe ouvrir de nouve
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5. CONCLUSIONS GÉNÉRALES • La m
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PART II: TECHNICAL ANALYSIS AND SYS
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1.1.1.1 Minor actinides Americium a
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thus preventing its dispersion in t
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By contrast, information about the
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DIDPA [5] (see Figure II.3) process
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The generation of secondary effluen
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Figure II.5 TRPO process TRPO solve
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According to Jarvinen et al. in LAN
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curium. • Separation of americium
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1.1.4.4 Separation of technetium an
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The second option is production of
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Figure II.9 Fuel cycle actinide bur
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Figure II.11 Flow sheet of pyro-rep
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The metathetical reaction between L
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This is confirmed by the radiotoxic
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For the same burn-up as in the pure
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planned for a burn-up range of 1.5
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On the basis of the study, it is no
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In a given reactor system, the diff
Page 144 and 145: - deterioration of the effectivenes
Page 146 and 147: Table II.5 Mass balances for homoge
Page 148 and 149: manufacture is 2 years. 12×24 targ
Page 150 and 151: Figure II.14 MA-loading methods in
Page 152 and 153: Table II.7 Mass balances for homoge
Page 154 and 155: Table II.8 Mass balances for hetero
Page 156 and 157: Core characteristics above: The fol
Page 158 and 159: Figure II.15 Concept of double stra
Page 160 and 161: Figure II.16 Concept of accelerator
Page 162 and 163: In Reference [99], the sodium coole
Page 164 and 165: In Germany, some small activities r
Page 166 and 167: OECD/NEA programmes The OECD/NEA Nu
Page 168 and 169: As a part of MA nuclear data evalua
Page 170 and 171: Table II.13 Pu and minor actinide b
Page 172 and 173: 2.4.1.3 Transmutation in light wate
Page 174 and 175: 3. DESCRIPTION OF CURRENT TRENDS IN
Page 176 and 177: The SPIN programme studied various
Page 178 and 179: • the RP1-2 scenario is compared
Page 180 and 181: Mass balance The MA mass balance, f
Page 182 and 183: 4. IMPACT OF P&T ON RISK ASSESSMENT
Page 184 and 185: For deterministic effects, in the c
Page 186 and 187: • accounting for a number of safe
Page 188 and 189: Table II.17 Effective dose coeffici
Page 190 and 191: MOX fuel and recycling of recovered
Page 192 and 193: Figure II.22 Potential radioactivit
Page 196 and 197: Curium is assumed to be stored for
Page 198 and 199: Figure II.25 shows the radiotoxicit
Page 200 and 201: decrease is obtained in the radioto
Page 202 and 203: 4.4 Risk and hazard assessment over
Page 204 and 205: 4.4.2 Radiological impact of waste
Page 206 and 207: 0.191 man-Sv/TWhe and the RFC with
Page 208 and 209: • conventional reprocessing does
Page 210 and 211: The maximum inventory of reactor co
Page 212 and 213: pursued. Since 137 Cs and 90 Sr are
Page 214 and 215: Figure II.26 Surface facilities. Ge
Page 216 and 217: Doses are controlled by 36 Cl up to
Page 218 and 219: Figure II.30 Overview of the canist
Page 220 and 221: surface. The reference repository i
Page 222 and 223: Figure II.34 Cavern-convection scen
Page 224 and 225: Figure II.36 Normal evolution scena
Page 226 and 227: considerable energy release as a re
Page 228 and 229: • taking into account the potenti
Page 230 and 231: • on the subject of transmutation
Page 232 and 233: [12] Arnaud-Neu, F., et al., “Cal
Page 234 and 235: Fuel”, Proc. Int. Conf. on Future
Page 236 and 237: [64] Arai, T., Suzuki, Y., Handa, M
Page 238 and 239: [88] Murata, H., and Mukaiyama, T.,
Page 240 and 241: [117] Gudowski, W., “Accelerator-
Page 242 and 243: [146] D’angelo, A., Marimbeau, P.
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[172] OECD/NEA and IAEA, Uranium: R
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[202] Schmidt, E., Zamorani, E., Ha
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