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1.1.4.4 Separation of technetium and platinum group metals (PGM) Two chemical methods have been developed at JAERI for the Tc and PGM separation from the DIDPA raffinate generated from actinides extraction from HLLW: the precipitation method by a denitration with formic acid and the adsorption method with active carbon. The former method might be more effective in practical use because it avoids generation of secondary waste even though the recovery of Tc is estimated to be about 95% as compared with more than 99.9% in the latter method [35]. The demonstration of these methods with real HLLW is proceeding at JAERI. 1.1.5 Conclusions Table II.2 shows the status of R&D under way on the various elementary processes considered. Table II.2. Status of R&D on aqueous separation techniques Phase 1 Phase 2 Phase 3 Remarks U and Pu separation (PUREX) – – – achieved industrially Np separation (PUREX) q 95% separation (PUREX) (DIDPA) (HDEHP) (TRUEX) q q q q >95% separation Am + Cm separation: * based on An/Ln co-extraction (TALSPEAK) (DIDPA) (TRUEX) (TRPO) (DIAMEX) * based on An selective extraction (TPTZ) (Picolinamides) (CYANEX 301) * based on precipitation (Ferricyanide) Am separation in the oxidised state Tc separation q q q q q q q SF=5 900 q (SESAME) q Am/Cm separation (PUREX) q soluble Tc (PUREX) q insoluble Tc Tc - PGM separation (Denitration precipitation) (Active carbon adsorption) q q I separation (PUREX) q 95% separation Zr separation (PUREX) q Cs separation (Calixarenes) (Zeolite) q q Sr separation (Titanic acid) q Cs and Sr separation (Dicarbollides) q Pd (PGM), Se, Ru separation (Electrolytic extraction) q soluble Pd, Se, etc. q 130
Three phases can be distinguished: • phase 1 corresponds to research on the principles of the process. In many cases, it overlaps the basic research conducted in the laboratory (for example, research on new extractant compounds). Its completion corresponds to the scientific feasibility of the process. • phase 2 is the process development step. It includes all research designed to develop the complete flow chart, describe its application, and guarantee its performance. The conclusion of this step corresponds to the technical feasibility of the process. • phase 3 relates to the industrialisation of the process. It is aimed to ensure overall active operations in industrial conditions. In practice, these studies are essentially conducted by engineering design. It terminates in the industrial feasibility of the process and its potential application in an industrial installation. Note that the current approach is based on separation element by element. The conditions of a possible grouping of certain elements would simplify the overall management. Moreover, some aspects of the separation processes have not yet been covered by the R&D programmes. These include the preparation of solid products for the fabrication of targets and fuels, for which the specification (product type and purity) remains to be determined. In addition, the development of new extractant molecules such as diphosphine dioxide is carried out in Russia. Researchers in India are working on the examination of sulfoxide type extractants. These research activities have also the potential to contribute to the development of advanced separation technology. 1.2 Non-aqueous methods An advanced nuclear fuel cycle is under development based on pyrochemical processes in order to achieve a compact, economic and non-proliferative recycling process. R&D on oxide fuel, metal fuel and nitride fuel are carried out to assess the technological feasibility of pyrochemical process with electrorefining and reductive extraction. This process has a feature that complete separation is difficult. 1.2.1 Pyrochemical reprocessing of oxide fuels for oxide fuel cycle The Research Institute of Atomic Reactor (RIAR) in Russia has been developing a pyrochemical reprocessing method based on the electrorefining of oxides combined with vibro-pack fuel fabrication since the early 1960s [39]. Pyrochemical reprocessing can be carried out by two ways: separation of UO 2 and PuO 2 during process and joint co-deposition of (U, Pu)O 2 . Figure II.8 shows the flow diagram of the first pyrochemical reprocessing option. After decladding of fuel pins, granulated or powdered oxides are chlorinated at 600~650°C in a pyrographite crucible by passing chlorine gas in order to dissolve uranium and plutonium as UO 2 2+ and Pu 4+ in molten NaCl-KCl. In the second stage, uranium oxychloride is electrolysed to deposit UO 2 at the cathode by using a potential at which PuO 2 is not co-deposited. In the third stage, crystallised PuO 2 is precipitated from the salt by circulating a mixture of oxygen and chlorine gas. More than 99% of plutonium from fuel can be precipitated by this process. After recovering plutonium, UO 2 is deposited at the cathode by supplementary electrorefining. 131
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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
Page 73 and 74: plutonium et environ 2 m 3 de déch
Page 75 and 76: 2.3 Technologie de fabrication des
Page 77: cadre de la coopération EFTTRA ont
Page 80 and 81: On peut voir sur la Figure I.4 les
Page 82 and 83: Figure I.4 Flux de matières dans u
Page 84 and 85: À court terme, les produits de fis
Page 86 and 87: Par conséquent, au cas où l’on
Page 88 and 89: De nombreux laboratoires dans le mo
Page 90 and 91: usé devrait représenter environ 3
Page 92 and 93: le nucléide le plus gênant est le
Page 94 and 95: transuraniens. Pour obtenir un taux
Page 96 and 97: On peut considérer des opérations
Page 98 and 99: devrait en principe ouvrir de nouve
Page 101: 5. CONCLUSIONS GÉNÉRALES • La m
Page 105: PART II: TECHNICAL ANALYSIS AND SYS
Page 108 and 109: 1.1.1.1 Minor actinides Americium a
Page 110 and 111: thus preventing its dispersion in t
Page 112 and 113: By contrast, information about the
Page 114 and 115: DIDPA [5] (see Figure II.3) process
Page 116 and 117: The generation of secondary effluen
Page 118 and 119: Figure II.5 TRPO process TRPO solve
Page 120 and 121: According to Jarvinen et al. in LAN
Page 122 and 123: curium. • Separation of americium
Page 126 and 127: The second option is production of
Page 128 and 129: Figure II.9 Fuel cycle actinide bur
Page 130 and 131: Figure II.11 Flow sheet of pyro-rep
Page 132 and 133: The metathetical reaction between L
Page 134 and 135: This is confirmed by the radiotoxic
Page 136 and 137: For the same burn-up as in the pure
Page 138 and 139: planned for a burn-up range of 1.5
Page 140 and 141: On the basis of the study, it is no
Page 142 and 143: 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
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3. DESCRIPTION OF CURRENT TRENDS IN
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The SPIN programme studied various
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• the RP1-2 scenario is compared
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Mass balance The MA mass balance, f
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4. IMPACT OF P&T ON RISK ASSESSMENT
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For deterministic effects, in the c
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• accounting for a number of safe
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Table II.17 Effective dose coeffici
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MOX fuel and recycling of recovered
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Figure II.22 Potential radioactivit
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Moreover, plutonium recycling and m
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Curium is assumed to be stored for
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Figure II.25 shows the radiotoxicit
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decrease is obtained in the radioto
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4.4 Risk and hazard assessment over
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4.4.2 Radiological impact of waste
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0.191 man-Sv/TWhe and the RFC with
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• conventional reprocessing does
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The maximum inventory of reactor co
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pursued. Since 137 Cs and 90 Sr are
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Figure II.26 Surface facilities. Ge
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Doses are controlled by 36 Cl up to
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Figure II.30 Overview of the canist
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surface. The reference repository i
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Figure II.34 Cavern-convection scen
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Figure II.36 Normal evolution scena
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considerable energy release as a re
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• taking into account the potenti
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• on the subject of transmutation
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[12] Arnaud-Neu, F., et al., “Cal
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Fuel”, Proc. Int. Conf. on Future
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[64] Arai, T., Suzuki, Y., Handa, M
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[88] Murata, H., and Mukaiyama, T.,
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[117] Gudowski, W., “Accelerator-
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[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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