V. Bukhal1, K. Husak1 , I. Zhuk1 , A. Safronava1, T. Korbut1, S. Tyutyunnikov2, M. Kadykov2,
W. Furman2, A. Patapenka1, V Chilap3, A. Chinenov3
1. JINPR-Sosny Belarus, Minsk
2. JINR Russia, Dubna
3. CPTP “Atomenergomash”, Russia, Moscow
The XII-th International School-Seminar
«The Actual Problems of Microworld Physics»
Gomel, Belarus, July 22 - August 2, 2013

Nuclear waste transmutation using neutrons
(brief introduction)

Study of ADS for transmutation
Experiments of the collaboration “EpT”

Experimental subcritical setup Quinta


Solid State Nuclear Track Detectors (SSNTD)
for (spatial and energy distribution of
neutrons,
spatial distribution of fission
reaction rates, beam monitoring
2
The total amount of
spent fuel in the world
~ 320 000 tones of
heavy metal
Solution
Waste
transmutation
3
The transmutation of fission products and higher actinides can be effectively
done by means of the placement into an intensive neutron field
One way to obtain intense
neutron sources is to use
a hybrid sub-critical
reactor-accelerator system
called Accelerator-Driven System
Even large neutron flux densities in a classical nuclear reactor (typically 1014
neutrons∙cm−2∙s−1) are not efficient enough for transmutation purposes.
Required flux for ADS should be at least two orders bigger to enable conversion
of nuclei with low absorption cross-sections and a few-step capture process in the
case of higher actinides. To meet such requirements, the spallation reactions
on a thick target can be used as an intensive source of neutrons
4
In the range of countries studying of ADS for transmutation is included in the
national research programs:
J-PARC project in Japan
RACE project in USA
EUROTRANS in EU
MYRRHA project in Belgium
YALINA-Booster Facility in Belarus
Experiments with spallation neutron sources are focused on future
transmutation use of the accelerator driven systems:
Megawatt Spallation Target Pilot Experiment (Megapie) experiment studied the
behavior of a target under extreme thermal and radiation load
Transmutation Experimental Facility (TEF) experiment in J-PARC studies
behavior of subcritical ADS under various beam conditions
Planned project Multi-purpose hybrid research reactor for high-tech
applications (MYRRHA) will combine both directions.
5
YALINA-Booster Facility
(Joint Institute for Power and Nuclear Research – Sosny, NASB)
It is a multizone subcritical assembly driven by an external neutron source: a 252Cf source
or a neutron generator (deuteron accelerator with deuterium or tritium target)
Pb target
Fast zone 1 – U met 90% in lead
Fast zone 2 – UO2 36% in lead
Absorber zone - boron carbide (B4C), NatU
Thermal zone – UO2 10% in polyethylene
All surrounded by Graphite
Lead subassembly of
the fast zone
Polyethylene
subassembly of the
thermal zone
6
7




1963-69, Investigation of neutron multiplicity in massive targets from metallic
Uranium (m ~ 3 t, 56×56×64 cm3, from uranium bar 2×4×8 cm3) with 10 cm
lead shielding under proton irradiations (energy range 0.3-0.66 GeV) Vasillkov
et al.
1965-68, Investigation of neutron multiplicity and neutron yields in massive
Lead targets (cylinder diameter 10-26 cm, length 55 cm) under proton
irradiations (energy range 0.4-0.66 GeV) Vasillkov et al.
1979-84, Investigation of neutron multiplicity and neutron yields in massive
Lead targets (cylinder diameter 10-26 cm, length 60-76 cm) under proton
irradiations (energy range 0.97-8.1 GeV) Vasillkov, Yurevich et al.
1987-92, Investigation of neutron generation and transport in massive Lead
targets 50×50×80 cm3 under charged particle (protons, alpha-particles,
deuterons, 12C ions) irradiations (energy range 3.6-8.1 GeV) – project “Energy” Tolstov et al.
The end of 1990s - project “Energy plus Transmutation” (EpT) within the
framework of research program “Investigations of physical aspect of
electronuclear energy generation and atomic reactors radioactive waste
transmutation using high energy beams of synchrophasotron/nuclotron JINR
(Dubna)”
8
At the moment, scientists from the following research institutes and countries are taking
part in the collaboration: Joint Institute for Nuclear Research, Dubna, Russia
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Aristotle University, Thessaloniki, Greece
Institute of Nuclear Sciences,Vinca, Belgrad, Serbia
Nuclear Physics Institute, Rez near Praha , Czech Republic
Joint Institute of Power and Nuclear Research, Sosny, Minsk, Belarus
University, Department of High Energy Physics, Sydney, Australia
Stepanov Institute of Physics, Minsk, Belarus
Philipps-Universität, Marburg, Germany
Institute of Atomic Energy, Otwock-Swierk near Warzhawa, Poland
Kharkov Institute of Physics and Technology, Kharkov, Ukraine
Technical University, Darmstadt, Germany
Czech Technical University in Prague, Czech Republic
Institute of Physics and Technology NASK, Almaty, Republic Kazakhstan
University of Rajasthan, Jaipur, India
National University, Ulan-Bator, Mongolia
Bhabha Atomic Research Centre, Mumbai, India
9
Assemblies of the collaboration “Energy plus Transmutation”:
 Lead targets + paraffin moderator (Gamma-2).
The leaders: M. Krivopustov, R. Brandt
 Energy plus Transmutation setup
The leader: M. Krivopustov
 Lead targets + graphite moderator (Gamma-MD).
The leaders: M. Krivopustov, S. Tyutyunnikov, M. Kadykov
Since 2009 the collaboration has been renamed to
“Energy and Transmutation of Radioactive Waste” (E&T RAW)
 Natural uranium target + lead shielding (QUINTA)
The leaders: S. Tyutyunnikov, M. Kadykov
Future project:
 Large Uranium target (19,5 t)
The leaders: S. Tyutyunnikov, M. Kadykov
10
The main goals of (E&T RAW) project are to study the basis characteristics of neutron
fields inside deep subcritical quasi-infinite AC made of depleted uranium metal,
the spatial distributions of core nuclei fission, the production of 239Pu nuclei, the
transmutation reaction rates of long lived minor actinides and fission products as
well as to define optimal energy of incident beam for transmutation RAW and
energy production
All RNT engineering problems including creation of necessary accelerator have to be
discussed practically after detailed study and verification of basic physics ideas of
proposed approach.
At JINR there are very favorable conditions
to investigate such type of ADS.
There is the suitable accelerator NUCLOTRON
with deuteron and proton beams
to energy of 5 GeV per nucleon.
Beside that there is available the extended
natural uranium metal target assembly QUINTA
and the quasi-infinite depleted uranium
metal target setup (19.5t, 120cm x 100cm)
11
An essentially new scheme of the electronuclear method based on
relativistic nuclear technology (RNT) is considered. This is based on
the use of the neutron spectrum forming in the deep subcritical
active core, much harder than created in chain fission process
Main physical idea of RNT approach is:
- to use deep subcritical and quasi-infinite (with negligible neutron
leakage) multiplying target of natural (depleted) uranium or thorium;
- to use proton or deuteron incident beam with (5 – 10) GeV
Such ADS can provide extremely hard neutron spectrum within the
active core and ensure an effective burning of core material as well
as spent nuclear fuel added to the initial core without its preliminary
radiochemical reprocessing
It is expected that such a spectrum would permit one to burn for
energy production natural (depleted) uranium or thorium and
simultaneously utilize the long-lived components of spent nuclear
fuel of nuclear power plants
12
13
Scheme of Pb-target without moderator
2.5 сm
7.5 сm
12.5сm
1
2
17.5сm
3
4
Pb-target
8 сm
Beam
20 сm
14
Scheme of Pb-target with paraffin moderator
of 6 cm thickness
4.3 сm
1
2.5 сm
7.5 сm
2
12.5 сm
3
17.5 сm
4
22.5 сm 25.4 сm
5
6
7
Pb-target
5 сm
20 сm
Beam
8 сm
Paraffin
20 сm
31 сm
15
Scheme of U/Pb-target with paraffin moderator
10.0 сm
2
12.5 сm
3
4
C
Beam
17.5 сm
22.5 сm 25.4 сm
5
6
7
Paraffin
U-target
20 cm
7.5 сm
8 cm
1
2.5 сm
3.6 сm
4.3 сm
Pb-target
5 сm
21 сm
31 сm
16
Scheme of massive lead target
Experiments aimed at the research of the spallation neutron
generation process
8
Y
50 cm
11
50 cm
p
1
2
3
4
5
6
7
Z
80 cm
17
Scheme of U/Pb setup "Energy plus
Transmutation” consist of 2 sections
Стеклотекстолит d=3 мм
U-blanket
Pb-target
1,5 GeV
Proton beam
wood
Кадмий
Текстолит 30 мм
Полиэтилен
d=1 мм
 = 0,7 г/cm3
Cross-sectional side view
Front view
18
Scheme of U/Pb setup "Energy plus Transmutation”
consist of 3 sections
b)
Blanket
Blanket
Deuteron
beam
Detectors
plate
Lead
protection
Lead
protection
Front view
Cross-sectional side view
19
Scheme of U/Pb setup "Energy plus Transmutation”
consist of 4 sections
20
Set up
with cylindrical
lead target
and big graphite
moderator
21
The uranium target QUINTA simulates the central part
of a quasi infinite active core RNT-reactor with the
negligible small leaking neutron
- 4 identical sections
- each section:
- 61 cylindrical blocks
(d=36 mm, l = 104 mm)
of metallic natural uranium
sealed in aluminum housing
- total mass of uranium 104.92 kg
- front section has the cylindrical input
beam channel diameter 80 mm
- total mass of uranium in the target
assembly is close to 500 kg
mtarget ~ 540 kg
22
To prevent the free passage of the some part of incident beam
through the horizontal space between the tightly packed uranium
cylinder an axis of the target assembly set with the rotation of 2
degrees with respect to the beam axis
Top view
Input beam window
23
In experiments of December 2011 and March 2012 there was
added to the uranium target the lead blanket thickness of 10 cm
with the input beam window size of the 150x150 mm
Cross cut
d
24
The science of SSNT detectors was born in 1958 when D.A. Young discovered
the first tracks in a crystal of LiF
The etch pits, later called «tracks», were found in a LiF crystal which was
previously placed in contact with a uranium foil, irradiated with slow
neutrons and treated with a chemically aggressive solution
The damaged regions constituted more chemically active zones than the
surrounding undamaged areas
In 1959 Silk and Barnes reported the finding of damaged regions in mica. They
used the transmission electron microscope to investigate tracks of heavy
charged particles in mica
Under an optical microscope
Detectors after etching
Cross-section
of a foil-mica
detector sandwich
25
SSNTD technique is based on relation of tracks density and flux
density of investigated neutron field
Track detector with fission foil (source of fission fragment) is irradiated
in neutron field. After this the tracks are formed on the track detector
surface
N
i
q
A
i
Track detectors

  d  P 
i
q
q
q
i
f
( E ) ( E )dE
P
fission foil
0
Sensor sensitivity coefficient:
k
sens
q
A
i
  q dq q
i
Sensor
The technique was developed by I. Zhuk and A. Malikhin
was applied in fission reactions rate measurements in reactor systems
26


Studying spatial distributions of fission
reactions in the setup volume
(neutron-physical characteristics)
Determination of the primary beam
parameters:
 Beam position on the target
 Beam shape
 Beam intensity
27
Each plate locates between sections
Detectors plate
Track
detectors
R=120
R=80
R=40
R=0
R=-80
Spatial distributions of 238U fission
and radioactive capture reactions
239Pu
and
accumulation
are
obtained by integrating the
measured parameters over the
setup volume
28
For adequate experimental results evaluation it is necessary to take
account of the precise experiment geometry, namely:
- beam axis shift relative to the setup main axis,
- shape and size of the incident beam.
Beam parameters during the irradiation are determined from solid state
nuclear track detectors (based on Pb foils)
Track detectors are mounted directly
to the front of the QUINTA setup
In detail all obtained results are in the next reports
29

The basic simplicity of its methodology

The low cost of its materials

The great universality of its possible applications





The compact geometry of the detectors
Their ability in certain cases to preserve their track record for
almost infinite length of time
They do not need any electronic/electric instrumentation; they
can be deployed under field conditions and in remote fairly
inaccessible places for long durations of time without the
need for human intervention or back up except for initial
placement and final retrieval
Off-line analysis gives an opportunity to use many sensors for
precise estimation of approximation function parameters
Sensors can be located in any place, even straight on the
target
30
Future project:
 Large Uranium target (19.5 t, diameter 120 cm, length 100 cm)
The leaders: S. Tyutyunnikov, M. Kadykov
The results of the previous experiments carried out at
JINR demonstrate the validity of basic principles of RNT.
Here it is important to note that basic aim of all
measurements with this previous targets is to prepare
and to test the experimental technique for realization
of main research program with Large Uranium target
The main goals of (E&T RAW) project are to study the
basis characteristics of neutron fields inside deep
subcritical quasi-infinite active core made of depleted
uranium metal, the spatial distributions of core nuclei
fission, the production of 239Pu nuclei, the
transmutation reaction rates of long lived minor
actinides and fission products as well as to define
optimal energy of incident beam for transmutation RAW
and energy production
31
We would like to thank
Veksler and Baldin Laboratory of High Energies (VBLHE),
Joint Institute for Nuclear Research (JINR), Dubna, Russia
and staff of the Nuclotron accelerator for providing us with
the research facilities used in these experiments and
personally the projects leaders
S. Tyutyunnikov and M. Kadykov
for the possibility to take part in the experiments
JINR for the hospitality during stay in Dubna
BSU National science-educational center of particle physics
and high-energy physics for organizational and financial
support and personally N. Shumeiko
National academy of science of Belarus and leaders of
JIPNR-Sosny for supporting work in frame of state
programs fundamental research
32
33