OECD-NEA Task Force on Potential Benefits andImpacts of Advanced Fuel Cycles with Partitioning andTransmutation: Summary of Major Findings
Massimo SALVATORES1,2 , Jan MARIVOET3 , Hiroyuki OIGAWA4 , Roald
WIGELAND2 , Horst GECKEIS5 , Klaus GOMPPER5 , Anne SATURNIN1 ,Jean-Francois MILOT1, Alain ZAETTA1 , Temitope TAIWO6 , and Yong-Joon
CHOI7
1 Commissariat à l‘Energie Atomique et aux Energies Alternatives (CEA), France
2 Idaho National Laboratory (INL), USA
3 Centre d'Etude de l'Energie Nucleaire (SCK/CEN), Belgium
4 Japan Atomic Energy Agency (JAEA), Japan
5 Karlsruher Institut für Technologie (KIT), Germany
6 Argonne National Laboratory (ANL), USA
7 Nuclear Energy Agency, Organisation for Economic Co-operation and Development(OECD/NEA)« For a successful technology, reality must takeprecedence over public relations, for nature cannot befooled »Richard Feyman(Challenger Commission Report, 1986)

Introduction

Whatever the impact of the recent events on nuclear development
policies in different countries, the need for a sound and well accepted
waste management remains a major issue
Both technical and societal arguments have to be considered
In this context, the analysis and consensus building on the potential
benefits of Partitioning and Transmutation strategies, is very important.
In fact Partitioning and Transmutation (P&T) of the actinide elements
has been considered as a way of reducing the burden on a geologic
disposal, since the P&T strategy of recycling actinides allows inprinciple a combined reduction of the amount of radioactive waste to
be stored and the associated residual heat.

P&T and simulation studies

Evolution with time of P&T focus and studies

Simulation of radiotoxicity reduction vs. time (Ingestion radiotoxicity
normalized to natural uranium and decay products as occurs in naturaluranium ore).

One
PuMOX
recycling in PWR
Mono10000

Multiple
Pu recycling
in PWR
Recyclage
Pu en REP
Pu
and Am recycling
in PWR
Cmaudisposed
Recyclage
Pu+Am en
REP –Cm
CSDV
Pu
recycling Pu
in FNR
Recyclage
en RNRPu
and MA recycling
in FNR en RNR
Recyclage
Pu+Np+Am+Cm

w/Twhé

1000

Oncecyclethroughouvert cyclePu,
Am recycling
in PWR– Cm
storedRecyclage
Pu+Am
en REPCm
entreposé

100

1010.110MA partitioning andtransmutation

1001000

10000
years
années

1000001000000

Pu recycling
no MA partitioning

Simulation of different P&T strategies effect on the evolution of the longterm decay heat

The NEA Task ForceThe study that has been performed by our Task Force within the Working Party on
Scientific Issues of the Fuel Cycle (WPFC) of the OECD NEA Nuclear ScienceCommittee had the objective to gather and analyse results of different studies
performed to assess the potential impact of P&T on different types ofrepositories in different licensing and regulatory environments.
Criteria, metrics and impact measures have been analysed and compared, in orderto give an objective comparison on the state of the art that can help to shapedecisions on different options of future advanced fuel cycles.
A final report of the Task Force is available: http://www.oecdnea.org/science/reports/2011/6894-benefits-impacts-advanced-fuel.pdf
The purpose of this presentation is to summarize the main finding of that study
The consensual outcome of the present assessment reflects for the different
expertise and background of the members of the Task Force, spanning fromreactor safety and fuel cycle physics to radiochemistry and geologic disposal
concepts analysis.

Summary of Past Studies on the Impact of P&T
Past studies including the specific analysis of the possible benefit and impact of
P&T have been reviewed and compared in terms of the following criteria:a) Peak dose rateb) Radiotoxicityc) Decay heatd) Waste form, volume and masse) Uncertaintyf) Other aspects such as proliferation and cost.
The comparison among independent studies by different countries and regions inthe world, has been crucial to extract the essence of various results and to build acommon understandings.

IAEA, “Implications of Partitioning and Transmutation in Radioactive Waste Management”, TechnicalReport Series No. 435, International Atomic Energy Agency, (2004).
OECD/NEA, “Advanced Nuclear Fuel Cycles and Radioactive Waste Management”, NEA No. 5990,(2006)
W. von Lensa, et al. (ed.), “RED-IMPACT, Impact of Partitioning, Transmutation and Waste Reduction
Technologies on the Final Nuclear Waste Disposal: Synthesis Report”, (2007)
J. Marivoet, et al., “Impact of Advanced Fuel Cycle Scenarios on Geological Disposal”, Euradwaste’08 Conference, (2008).
H. Geckeis, et al., “Impact of Innovative Nuclear Fuel Cycles on Geological Disposal”, Annual
Meeting of Nuclear Technology (2008).
R. Wigeland, et al., “Separations and Transmutation Criteria to Improve Utilization of a Geologic
Repository”, Nucl. Technol., 154, 95 (2006)
R. Wigeland, et al., “Impact on Geologic Repository Usage from Limited Actinide Recycle in
Pressurized Light Water Reactors”, J. Nucl. Sci. Technol., 44(3), 1 (2007).
C. W. Forsberg, “Rethinking High-level Waste Disposal: Separate Disposal of High-heat
Radionuclides (90Sr and 137Cs) ”, Nucl. Technol., 131, 252 (2000).
K. Nishihara, et al., “Impact of Partitioning and Transmutation on LWR High-Level Waste Disposal”, J.
Nucl. Sci. Technol., 45(1), 84 (2008)
H. Oigawa, et al., “Partitioning and Transmutation Technology in Japan and its Benefit on High-level
Waste Management”, Proc. of GLOBAL2007, Int. Conf. on Advanced Nuclear Fuel Cycles andSystems, Global 2007, Boise, Idaho, September 9-13, 2007.
H. Oigawa, et al., “Concept of Waste Management and Geological Disposal Incorporating Partitioningand Transmutation Technology”, Proc. OECD/NEA 10th Information Exchange Meeting on Actinideand Fission Product Partitioning and Transmutation, 6-10 October 2008, Mito, Japan, (2008).

1.0E-10

Dose (river pathway) (Sv/a/TWhe)

A1

1.0E-11
1.0E-12A2 hlw
A2 spf-mox
total A2
A3
B1

1.0E-13B2 hlw-uox
B2 hlw-mox

1.0E-14B2 hlw-ads
total B2

1.0E-15
1.0E-16
1.0E-17
1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

Time after canister failure (years)

Impact of the various fuel cycles on the dose calculated for the normal evolution scenario:- between 7,000 and 250,000 years: impact of direct disposal or reprocessing on the iodine content(doses are mainly due to I-129) of the waste- between 250,000 and 2 M years: the peak is mainly due to Se-79 and Sn-126- after 3 M years: doses due to actinides, which are significantly lower in the case of fuel cycles with fullrecycling of the actinides.
Ref. W. von Lensa, et al. (ed.), “RED-IMPACT, Impact of Partitioning,
Transmutation and Waste Reduction Technologies on the Final Nuclear
Waste Disposal: Synthesis Report”, (2007)

Role of ADS in Advanced Fuel Cycle:

Innovative Waste Management. Repository Area
Normalized by 32,000tHM of 45GWd/t spent fuelConventional Concept

Low-heating wastes (0.13km2)
CT: Cooling time before disposal

1.8 km2(Vertical emplacement in crystalline rock)

MA transmutation+
FP Partitioning
0.41 km2
MA transmutation+
FP Partitioning+
Long-term storage of Sr+Cs
0.015 km2

40,000 pieces of glass waste forms (1.8km2)(CT: 50 y)
5,100 pieces of Sr-Cs calcined forms (0.23km2)(CT: 130 y)
8,300 pieces of highly-loaded
glass waste forms (0.18km2)(CT: 5 y)
8,300 pieces of highly-loaded
glass waste forms (0.01km2)(CT: 45 y)
5,100 pieces of Sr-Cs calcined forms (0.005km2)(CT: 320 y)
Ref. : K. Nishihara, et al., “Impact of Partitioning and Transmutation on LWR
High-level Waste Disposal”, J. Nucl. Sci. Technol., 45(1), 84-97 (2008).

Major Findings of the Task Force The analysis performed has indicated that most recent studies havedemonstrated that the impact of P&T on geological disposal concepts canbe significant even if not overwhelmingly high.
 In fact, by reducing waste heat production a more efficient utilizationof repository mines is likely. In practice, the reduction of the thermal outputof the High Level Wastes by a factor of ~3 can reduce the needed repository
gallery length by a factor ~3 and the repository footprint up to a factor 9.
 The reduction of masses, volumes and heat allows a very favorable
flexibility in any storage strategy
 Moreover, even if radionuclide release from the waste to the environmentand related potential doses to the population are not significantly reduced by
P&T since mostly dominated by some long lived fission products, it isimportant to point out that a clear reduction of the actinide inventory in
the Highly Active Waste (HAW) reduces risks arising from less probableevolutions of a repository, i.e. increase of actinide mobility in certain
geochemical situations and radiological impact by human intrusion.

One significant effect of P&T is that the inventory of the emplaced
materials is much lower on an energy generated basis for the actinideelements.
This can have the effect of making the uncertainty about
repository performance less important.
In fact, the P&T can reduce the importance of uncertainties
both in normal evolution and in particular those related tohypothetical disruptive scenarios that can bring man in direct contact
with the disposed waste, since these scenarios are affected by thehazard (radiotoxicity) and not so much by the geology, and P&T of
the actinides does reduce the hazard of the emplaced materials.



By introducing P&T in the fuel cycle, the mass of actinides can besignificantly reduced in the HLW, and may be possible to reduce
HLW volume and mass (while long-lived low- and intermediate-waste
could sometimes increase).
The introduction of P&T could increase the options for
optimised waste forms.
For example, as for the vitrified waste, the density of the wasteelements in the glass matrix might be increased e.g. because of thereduced heat source.

Of the P&T impact studies examined by the Task Force, none
attempts a comprehensive assessment on the impact onproliferation resistance.
Evaluation Methodologies for proliferation resistance and physicalprotections have been developed but to date only very preliminary
attempts have been made to apply them to specific advanced fuelcycle strategies.

The radiotoxicity has been used as the index to demonstrate theeffect of MA transmutation. The Task Force did somewhat deemphasize this parameter
All the previous studies assumed 99 – 99.9% recovery of TRU, andeventually about two orders of magnitude reduction of radiotoxic
inventory were foreseen after several hundred years and later.
This index is also used to emphasise the effect of shortening the time
period needed to decay below a reference level.
As a reference level, the radiotoxicity of the initial natural uranium inequilibrium with its decay products has been used.
In fact, TRU transmutation shortens the time period needed to reduce
the radiotoxicity to the reference level to several hundred years,
though more than 100,000 years will be necessary in the case of direct
disposal.

However, it should be recognized that radiotoxicity alone may not be
the essential indicator of the effect of actinide partitioning and transmutationon the estimated dose rate for some repository concepts, since both
radiotoxicity and exposure pathway characteristics are needed to evaluate
repository performance.

Summary¾ A major outcome is the recognition that one significant effect of P&T is that theinventory of the emplaced materials is much lower on an energy generated
basis for the actinide elements that can have an impact on the repository, since byreducing waste heat production a more efficient utilization of the repository
space is expected.
¾ Moreover the inventory reduction can make the uncertainty about repository
performance less important both in normal evolution and in particular in case of
hypothetical disruptive scenarios that can bring man in direct contact with thedisposed waste, since the P&T of the actinides does reduce the hazard of theemplaced materials.
¾ It is also pointed out that, while P&T will never replace the need for a deep
geologic repository, P&T could significantly improve the public perception of theability to effectively manage radioactive wastes by largely reducing the TRU waste
masses to be stored and, consequently, to improve the public acceptance of ageologic repository. Both issues are important to future sustainability of nuclear
power.
¾ Major nuclear countries show a cautious attitude about P&T and favour
further studies, but it is recognized that P&T provides a much needed
flexibility in front of possible storage options, regulatory evolutions and thehandling of uncertainties.

¾ A final lesson learned:

If a man begins with certainties, he shall end in
doubts; but if he will be content to begin with doubts,
he shall end in certainties

Francis Bacon(The Advancement of Learning, 1605)