Transmutation of LLFPs
by DD, DT-fusion neutrons
-As part of the JST*-ImPACT** programFor the visits to Uppsala Univ., ITER, and Budker Inst.
Yoshi Hirooka
National Institute of Fusion Science, and
Graduate University for Advance Studies
with the contributions from:
Prof. Y. Nakashima (Univ. Tsukuba)
Prof. A. Iiyoshi, Prof. M. Sato and Dr. N. Yamamoto (Chubu Univ.)
*JST=Japan Science and Technology agency
Table of Contents
1. Background
1. What is “LLFP”?
2. What can we do about it?
3. What is the ImPACT program?
2. Current status of the JST-funded research
1. Conceptual study on LLFP transmutation
2. LAEMS-method for dry LLFP separation
3. GAMMA-10 sloshing ion formation modeling
3. Possible international collaborations
Fission products and magic numbers
0.1GW BWR burns 3kg of U235/day
What are the LLFPs in spent fuel?
•
•
•
•
•
•
•
•
•
•
•
U-235⇒ Half lifetime: 7.0 x108yrs
U-238⇒ Half lifetime: 4.5 x109yrs
Pu-238, 239, 240, 241⇒ Half lifetime< 2.4 x106yrs
Np-237⇒Half lifetime: 2.14 x106yrs
TRU
MA
3
Am-241, 243⇒ Half lifetime < 7.3 x10 yrs
Cm-244⇒ Half lifetime: 1.8 x10yrs
Tc-99⇒Half lifetime: 2.1 x105yrs
Zr-93 ⇒ Half lifetime: 1.5 x106yrs
Cs-135 ⇒ Half lifetime: 2.3 x106yrs
Pd-107 ⇒ Half lifetime: 6.5 x106yrs
Se-79 ⇒ Half lifetime: 2.95 x105yrs
What is the JST-ImPACT**program?
**ImPACT= Impulsing Paradigm Change through Disruptive Technologies program
(about $500M for 12 subjects)
Project 1: Development of separation and recovery technologies
Project 2: Obtained nuclear reaction data & new nuclear reaction control method
Project 3: Reaction theory modeling and simulation
Project 4: Evaluation of nuclear transmutation system and development of elemental technologies
Project 5: Process concept for design
Nuclides to be investigated in ImPACT
• Se-79⇒β-emitter
– Half lifetime: λ= (2.95+0.38) x105yrs
– Se-77, Se-78, Se-80 stable, Se-81 unstable)
⇒(n,2n), (n-capture)
• Zr-93⇒β-emitter
– Half lifetime: λ=1.5 x106yrs
– Zr-91, Zr-92, Zr-94 stable , Zr-95 unstable
⇒(n,2n), (n-capture)
• Pd-107⇒β-emitter
– Half lifetime: λ=6.5 x106yrs
– Pd-105, Pd-106 , Pd-108 stable, Pd-109 unstable
⇒(n,2n), (n-capture)
• Cs-135⇒β-emitter
– Half lifetime: λ=2.3 x106yrs
– Cs-133 stable, Cs-134 unstable (λ=2yrs), Cs-136 unstable (λ=13dys)
⇒(n,2n), (n-capture)
Nuclear reactions with Se-79
Direct transmutation by
DT-neutrons by (n,2n)
DD, DT, (n,2n)-neutrons capture
after multiple collisions
Se-79 ⇒Se-78
Se-79 ⇒Se-80
Nuclear reactions to form Se-79 ①
Se-78⇒Se-79 by n-capture
Se-79⇒Se-80 by n-capture
Nuclear reactions to form Se-79 ②
Se-80⇒Se-79 by (n,2n)
Se-79 ⇒ Se-80 by (n,2n)
Nuclear reactions with Zr-93
Direct transmutation by
DT-neutrons by (n,2n)
DD, DT, (n,2n)-neutrons capture
after multiple collisions
Zr-93 ⇒Zr-92
Zr-93 ⇒Zr-94
Nuclear reactions to form Zr-93 ②
Zr-94⇒Zr-93 by (n,2n)
Zr-93 ⇒ Zr-92 by (n,2n)
Nuclear reactions to form Zr-93 ①
Zr-92⇒Zr-93 by n-capture
Zr-93⇒Zr-94 by n-capture
Nuclear reactions with Pd-107
Direct transmutation by
DT-neutrons by (n,2n)
DD, DT, (n,2n)-neutrons capture
after multiple collisions
Pd-107 ⇒Pd-106
Pd-107 ⇒Pd-108
Nuclear reactions to form Pd-107①
Pd-106 ⇒ Pd-107 by n-capture
Pd-107 ⇒ Pd-108 by n-capture
Nuclear reactions to form Pd-107①
Pd-10⇒Pd-107 by (n,2n)
Pd-107 ⇒ Pd-106 by (n,2n)
Nuclear reactions with Cs-135
Direct transmutation by
DT-neutrons by (n,2n)
DD, DT, (n,2n)-neutrons capture
after multiple collisions
Cs-135 ⇒Cs-134
Cs-135 ⇒Cs-136
Nuclear reactions to form Cs-135 ①
Cs-134⇒Cs-135 by n-capture
Cs-135 ⇒ Cs-136 by n-capture
Nuclear reactions to form Cs-135 ②
Cs-136⇒Cs-135 by (n,2n)
Cs-135 ⇒ Cs-134 by (n,2n)
Nuclear reactions with Cs-136 ①
Cs-136⇒Cs-137 by n-capture
(13.6dys) (30yrs)
Transmutation simulated by the PHITS-code (v2.76)
-Geometry and nuclear characteristicsSpherical shell thickness: t (cm)
Number
density
(個/cm3)
Z
N
Zr93
40
53
1.557E-22 4.188E+22
Pd107
46
61
1.791E-22 6.713E+22
Se79
34
45
1.322E-22 3.237E+22
Cs135
55
80
2.260E-22 8.540E+21
t
Neutron
source
Mass
(g/atom)
Transmutation simulated by the PHITS-code (v2.76)
Surface density ~ 1016 1/cm2/s at the void radius of 10cm
Point source：1019n/s@⇒assuming DT-reaction neutron souce for E=14.1MeV
Zr93[4.19E22]
Thickness
(cm)
Volume
(cm3)
1
Pd107[6.71E22]
Se79[3.24E22]
Cs135[8.54E21]
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
3.812E+02
0.062
5.662E-01
0.119
4.724E-01
0.045
6.032E-01
0.0132
2.056E+00
5
3.665E+03
0.277
1.219E+00
0.621
8.705E-01
0.218
1.197E+00
0.0661
3.949E+00
10
1.361E+04
0.502
2.497E+00
1.253
1.602E+00
0.394
2.461E+00
0.1379
7.030E+00
50
6.964E+05
1.948
3.292E+01
2.787
3.685E+01
1.993
2.488E+01
0.5191
9.554E+01
100
4.849E+06
2.703
1.652E+02
2.794
2.559E+02
2.571
1.343E+02
0.8419
4.101E+02
200
3.609E+07
2.745
1.211E+03
2.794
1.905E+03
2.621
9.805E+02
1.2603
2.039E+03
500
5.395E+08
2.752
1.805E+04
2.794
2.848E+04
2.621
1.466E+04
2.2938
1.675E+04
Transmutation simulated by the PHITS-code (v2.76)
Surface density ~ 1016 1/cm2/s at the void radius of 10cm
Point source：1019n/s@⇒assuming DD-reaction neutron souce for E=2.45MeV
Zr93[4.19E22]
Thickness
(cm)
Volume
(cm3)
1
Pd107[6.71E22]
Se79[3.24E22]
Cs135[8.54E21]
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
Number
of
reactions
Reaction
half
lifetime
(yr)
3.812E+02
1.00E-03
3.510E+01
6.31E-03
8.909E+00
2.00E-03
1.357E+01
3.00E-04
9.048E+01
5
3.665E+03
8.00E-03
4.219E+01
1.38E-01
3.926E+00
1.50E-02
1.740E+01
8.00E-04
3.263E+02
10
1.361E+04
3.00E-02
4.179E+01
4.31E-01
4.658E+00
3.60E-02
2.693E+01
1.90E-03
5.102E+02
50
6.964E+05
6.59E-01
9.732E+01
9.99E-01
1.028E+02
7.29E-01
6.803E+01
1.89E-02
2.624E+03
100
4.849E+06
9.83E-01
4.542E+02
1
7.151E+02
9.89E-01
3.491E+02
6.25E-02
5.525E+03
200
3.609E+07
1
3.323E+03
1
5.322E+03
1
2.570E+03
2.28E-01
1.128E+04
500
5.395E+08
1
4.968E+04
1
7.956E+04
1
3.842E+04
7.53E-01
5.105E+04
Sloshing ions generation in GAMMA-10
Sloshing ions in a mirror machine
Sloshing ion data in GAMMA-10
Tperb=10KeV
Reaction rate [n/s]
Neutron flux [W/m2]
DD-reaction
~1012
~0.5
DT-reaction
~1014
~500
５
DD-neutron generation in GAMMA-10
ICRH⇒Tperp.
Y. Kiwamoto et al. Phys. Plasmas 3(1996)578.
Achieved
DTNS
Design
Beta (%)
60
60
Beam Power
(MW)
4
30
Beam Energy
(kV)
20
80
Ion Energy
(keV)
10
40
Electron Temp
(eV)
230
750
Density
(1020 m-3)
1
4
Energy
Confinement
Time (ms)
2
2
Pulse
Duration
5 ms
cw
GDT
TDF
９
Partitioning and Transmutation (P-T)
w/ P-T
w/o P-T
Nuclear reactor
Nuclear reactor
Spent fuel
Spent fuel
Re-processing
Re-processing-Partitioning
Pd, Pt
Vitrified waste
Recycled
Na-containing Sr, Cs
wastes
Dry re-processing
Other elements
Vitrified waste
JAEA 大井川宏之氏 「ＡＤＳ研究の現状と計画」講演資料より
１０
Magnetic mass separation done for U238-U235（1945)
r = M v /eB
L
i
i┴
Caltron @ ORNL in 1945 http://en.wikipedia.org/wiki/Calutron
１１
Laser ablation plasma for magnetic mass separation
Ablation plasma ions from C-target
C+
C+
Beam splitter +
C2
THG
C3+
YAG
Double-target setup
Laser ablation chamber
laser
SHG
C4+
HeNe
laser
C5+
ICCD movie of C-target ablation
LAEMS implemented in a poloidal divertor
Targets for mass separation
Laser for
target ablation
分離済み核種
取り出し
Fusion neutron applications for LLFP re-processing
Spent fuel
Dry/wet partitioning
Fusion neutrons
LLFP
Neutrons
Neutron
capture
Transmutation
Stable and/or
short lived nuclei
LAMS-separation
TRU
Neutrons
Neutron
capture
2nd FP
Summary and proposed collaboration
1.
Present status of the project funded by ImPACT
1.
2.
3.
2.
Possibilities of the transmutation of Se-79,Zr-93, Pd-107, Cs-135 by the use
of DD, DT fusion neutrons have been suggested.
Laser Ablation Electromagnetic Mass Separation (LAEMS) method has been
proposed as part of dry-processing of LLFP.
Mirror machines being proposed as a possible platform for the
transmutation of LLFP.
Next step in Japan and international collaborations(?)
1.
2.
3.
4.
Univ. Tsukuba GAMMA-10 being considered as a platform for the sloshing
ion formation for simulated LLFP transmutation.
Uppsala Univ. could support GAMMA-10 experimental work by modeling on
the optimization of sloshing ion formation
⇒JST-funded postdoc fellow
ITER-blanket modules could be proposed as a PoP test bed for LLFP
transmutation by DD, DT-fusion neutrons?
Any room for a discussion of the proposal: Can Budker Inst. GDT-mirror be
used as a platform for the PoP experiments on LLFP transmutation?
⇒JST will fund LLFP-transmutation experiments in GDT