Download TRANSMUTATION OF SPENT NUCLEAR FUEL

TRANSMUTATION
OF SPENT NUCLEAR FUEL
Author: Lukas Zavorka (email: zavorka(at)jinr.ru)
Laboratory of Nuclear Problems
Abstract: At the present time spent nuclear fuel as well as radioactive waste can be
managed only in this way: reprocessing and storage. Another one, transmutation,
represents a method how to dramatically decrease dangerousness and radiotoxicity of
spent fuel that has been used in operating power and research nuclear chain reactors.
Transmutation reaction consists in changes in the structure of atomic nuclei. These
changes lead to transformation of long-lived fission products and transuranium
elements into stable or relatively short-lived elements.
Basic description of the project:
The total amount of spent fuel that has been discharged globally is approximately
320 000 tons of heavy metal [1]. 97 percent of the spent fuel contains uranium and
plutonium, which can be reused after the reprocessing (MOX fuel). Higher actinides
that cannot be effectively burned in current types of nuclear chain reactors could be
transmuted by the much more intensive spallation neutron source, where reaction of
high-intensity beam of charged particles with heavy metal target elements (e.g. Pb,
U) leads to the massive production of neutrons.
Moreover, intensive spallation neutron source can be used for investigation of
utilization of natural/depleted uranium and thorium nuclear fuel without the use of
235U [2]. Another purpose of transmutation of transuranium elements is electrical
energy production.
In recent years scientific and practical interest in the feasibility of accelerator driven
systems (ADS) for transmutation of long-lived components of radioactive waste
(RAW) and, in the long-term outlook, for solution of global energy problems has
remained quite high [3]. Major feature and safety aspect of these systems is deeply
subcritical core (kef  0.94 ÷ 0.98).
In the framework of collaboration “Energy and Transmutation of Radioactive Waste”
several experiments have been carried out on Quinta (see Fig 1) or Gamma-3 setup
using proton and deuteron beam (up to 6 GeV) of Nuclotron-M accelerator. Some
other experiments have been realized using lead target irradiated by 660 MeV proton
beam of JINR Phasotron accelerator.
Primary purpose of experimental work consists in study of neutron field generated by
the spallation reaction in thick target. Neutron spectra dependencies, total number of
neutrons, spatial distribution around the target, cross sections and transmutation
yield measurements are being investigated in detail. It is also necessary to make a
comparrison of ex
xperimenta
al data witth theoretical predicctions usinng several nuclear
models and calculation codees.
Fig 1. C
Contributioons to the radiotoxiccity level off spent nucclear fuel [44]
Fig 2. Q
Quinta exp
perimental setup [E&
&TRW collaboration]
Student activities:
 become acquainted with terms: ADS, transmutation reaction, spallation
reaction, spallation neutron spectrum, neutron and charged particle activation
technique, gamma spectroscopy, HPGe detector, reaction rate, simulation tools
and codes, current international projects
 measuring and processing of gamma spectra of some irradiated transuranium
element
 data interpretation, presentation of obtained research results
Association with JINR international collaboration:
02-1-1107-2011/2013: Development and Creation of the Prototype of a Complex for
Radiotherapy and Applied Researches on Beams of Heavy Ion on the Nuclotron-M
03-4-1104-2011/2013: Investigations in the Field of Nuclear Physics with Neutrons
References:
[1] Svoboda O., “Experimental Study of Neutron Production and Transport for
ADTT”, Dissertation thesis, CTU Prague, 2010
[2] Adam J. et al. («E&T RAW Collaboration»), “Study of Deep Subcritical
Electronuclear Systems and Feasibility of Their Application for Energy
Production and Radioactive Waste Transmutation”, Preprint Nr. E1-2010-61,
JINR Dubna, 2010
[3] Furman W. et al., “Time-dependent spectra of neutrons emitted in interaction
of 1 and 4 GeV deuterons with massive natural uranium and lead target”,
Proc. of Intl. Conf. on Nuclear Data for Science and Technology ND2010, Jeju
Island, Korea
[4] Sheffield R.L., Pitcher E., “Application of Accelerators in Nuclear Waste
Management”, Beam Dynamics Newsletter, 49, ICFA, 2009