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