Thorium Energy Conference 29 Oct-1-st Nov 2012, Shanghai, China
Small Sized Sub-critical Thorium Liquid-fuel
Generator for the Venezuelan Nuclear
Program
L. Sajo-Bohus, E.D. Greaves, H. Barros, Universidad Simón Bolívar,
Apdo 89000 Caracas 1080A, Venezuela
In Memoriam: To Prof. Kazuo Furukawa “Champion for the Th-MSR” who passed away on the 14th of December 2011. May his dream of a thorium nuclear era
come true.
www.nuclear.fis.usb.ve
World energy reserve
Nuclear Power Plant operat. 436; 63 in constr.
18
104
33
24 20
386.5 441 TOTAL
C W enriched
UO2
0.05 4 Russia Others
-------- liquid
sodium PuO2 and
UO2
1.0 4 Japan, France, Russia Breeder (FBR)
C W enriched
UO2
12.3 12 Russia Water Graphite (RBMK)
C CO2
natural U (metal), enriched
UO2
10.8 18 UK Gas- Reactor (AGR & Magnox)
D2O W natural
UO2
24.3 44 Canada 'CANDU' (PHWR)
W W enriched
UO2
86.4 94 US, Japan, Sweden BWR
W water enriched
UO2
251.6 265 US, France, Japan,
Russia, China PWR
Moderator cooling fuel GWe units country Reactor
World industrial experience
Liquid Salt
Water and D2O
Gas
Liquid Metal
Nuclear energy policy have changed
Safety,
Proliferation Resistance and Physical Protection:
- unattractive for diversion or weapons-usable materials, acts of terrorism,
Waste management, and Economics
clear life-cycle cost and financial risk advantage
are now the major drivers in the design of GEN-IV reactors
Venezuelan nuclear program Agreement with Russia 2009
- Peaceful uses of nuclear science
- Scientific Information exchange
- Personnel training,
- Import and export of material
- Recognize IAEA Authority
- 10 year
Agreement with Russia 20010
- Construction of Research reactor for Medical and industrial applications
- Construction of Power reactor
Pres..Chávez –Pres. Putin
Pres..Chávez –Pres.Medvedev
Pres..Chávez
FUKUSIMA accident 2011
-Nuclear program suspended
-- Personnel training program in Russia continues
Agreement with Rosatom (Possibly to build)
1 reactor of 1.200 MW- VVER-1200
Rosatom experience: Novovoronezh-2-1 and Novovoronezh-2-22,
under construction The first will be operative this year. Projected 16 more by 2020.
1954, Obninsk, Rusia AM-1 of 30 MWth; Precursor of
RBMK Chernobyl
Venezuela Not a nuclear experienced country; why PWR?
Mineral extraction and ore processing
Large plants for Al, Fe, ...production
High temperature ionic liquid
Applications of nuclear techniques for crude monitoring
Uranium and thorium ore processing
Closing the gap for a nuclear
experience in Venezuela: go for MSR!
10
Localizado en el
macizo Guayanés
Cerro Impacto
Thorium wonder fuel
232Th only one isotope (except for about 10ppm of 230Th.
No fuel “enrichment” is required.
Chemically refined thorium is added directly to the molten salt
232Th in the reactor fuel is converted to the fissile 233U by the reaction:
232Th (n,γ) 233Th (β−: 22.3 m half-life) 233Pa (β−: 27 d half-life) 233U
Venezuelan Industrial experiences with molten salt:
Aluminium Processing
Pyrochemistry: increasingly acknowledged
unavoidable in the nuclear field.
MSR: fuel processing, spent fuel recycling, heat transfer,
Fluorides: stable at high temperature; high neutron flux
Corrosion in molten fluorides due to metals-oxidation
by uranium fluoride and/or oxidizing impurities;
selecting appropriate metallic materials and
designing effective purification method
Concept design for a zero-power MSR Starting point to establish the basic nuclear characteristics:
ZERO-POWER PHYSICS EXPERIMENTS ON THE MOLTEN-SALT REACTOR EXPERIMENT
B E. Prince, S. J. B a l l, J R. Engel, P. N. Haubenreich, T. W. Kerlin;
OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee, 1968
Drain Tank
Freeze Plug
Industrial experiences with molten salt
is one of the six innovative concepts of
reactor proposed by the “Generation IV International Forum” for future nuclear energy supply.
Furukawa collaboration
The Mini-FUJI targets shipping and the FUJI targets electricity a working prototype six years from the
project launch date
Advantages MSR-VEN Passive safety through fluid fuel form and low-pressures
High temperature high conversion efficiencies and air cooling of
drain tanks offers site flexibility away from water bodies.
fuel preparation low costs, no fuel fabrication costs. Solvent
7LiF-BeF main solutes ThF4 (233UF4 or 239PuF3)
Excellent chemistry match with thorium/uranium fuel cycle.
Stable Chemical Salts and
Impervious to radiation damage
unlimited fuel burn-up
continuous solvent recycling.
Fuel is highly unsuitable for weapons diversion
Salts: aggressive to metals and other
structural materials.
High-temperature: design challenges.
Technology: stagnated for 40 years.
LFTR technology is very different from the
water-cooled, enriched-uranium-fueled
reactors that are the basis for current nuclear
power generation, and is not yet fully
understood by regulatory agencies and
officials
Technical Challenge exists!
Liquid Fuel three functions
1.- As liquid fuel element,
2.- As heat transfer medium,
3.- As fuel processing medium.
Eutectic mixture of lithium fluoride and beryllium fluoride called FLIBE, with fertile thorium and fissile uranium or plutonium dissolved
in the fluoride molten salt.
7LiF - BeF2-ThF4-233UF4 ;
73,78 - 16 – 10 - 0,22 mol %
The technology for MSR reactor
Is closer to the Venezuelan industrial experience compared to any other type of nuclear reactor
We suggest for the Venezuelan nuclear program to go MSR
As a first step: lab experiments
Second step collaboration with other Labs
Further steps: larger assembly
The aim is to have a mini-Fuji of few MWth
19
Zero power assembly at the University Simon Bolivar
grafite
Monitoring system
shielding
Fuel in-let
252Cf – neutron source
2-nd stage
1-st stage
Preliminary studies molten salt reactor: delayed
neutrons effect on reactivity with fluid speed and Simulated Heat Transfer
0 10 20 30 40 50 60 700.7
0.75
0.8
0.85
0.9
0.95
1
delayed neutrons in the external loop
homogeneous MSR
Fuel salt velocity [cm/s]
Lo
ss o
f re
acti
vit
y
0 2 4 6 8 10 12 14
0
20
40
60
80
100
120
Delayed neutron residence time
6 group fission fragment neutron emitter
Delayed neutrons emitted during time (s)
In c
ore
% o
f d
elay
ed n
eutr
on
molten salt reactor: simplified neutron point kinetic equations
ANSYS-CFX thermal- hydraulics
Conclusions: not only for Venezuela, the best option is MSR
Energy independence is possible and affordable.
Thorium, an abundant natural resource.
Liquid-fluoride thorium fuel.
Demonstrated technology that has been forgotten.
Experience with molten salt (USA, Russia, China,France, India....)
Simulations as a first approachStart with a zero power reactor
Continue with mini Fuji-MSR to produce: electricity, desalinated water
Zherebtsov A., et al., (2008), Experimental Study of Molten Salt Technology for Safe, Low-Waste and Proliferation Resistant Treatment of Radioactive Waste and Plutonium in Accelerator Driven and Critical Systems, Int´l Sci. Centre, Moscow, Russian Federation
We will fly again the
MSR