IAEA Technical Meet onStrategies and Opportunities for the Management of

Spent Fuel from Power Reactors in the Longer TimeframeNovember 26, 2019

Advances in Vitrification Technology in India

Dr. G. SUGILAL

Nuclear Recycle Group

BHABHA ATOMIC RESEARCH CENTRE

Overview

Closed Fuel Cycle and Vitrification Process

Evolution of Vitrification Technology in India

Induction Heated Metallic Melter

Joule Heated Ceramic Melter

Cold Crucible Induction Melter

Summary and Road Ahead

Metallic Melter

Ceramic Melter

Cold Crucible

INDIAN NUCLEAR FUEL CYCLE

• Spent Fuel: A Resource Material• Recovery and Reuse• Thorium utilization• Waste partitioning• Reduced repository size

• Spent Fuel Reprocessing• High Level Liquid Waste• Management of HLW

Closed Fuel Cycle

Immobilization of high level liquid waste in glass matrix

Internationally accepted for conditioning HLW

Borosilicate glasses are being widely used

Stability

Durability

Flexibility

Feasibility

VITRIFICATION OF HIGH LEVEL LIQUID WASTE

Vitrified Product SS Canister

Developmentof waste glassCollaborationwith CGCRI

Development of first HLLW glass matrix for Tarapur

(WO-24%)

Development of glass matrix at Trombay

(WO-21%)

19741990

2002

2013

2015

2017

Development of glass matrix for short cooled waste of RR

(WO-26%)

Sodium Borosilicate

Barium Borosilicate

Barium Borosilicate

Development of Cs specific glass matrix

(Cs- 2 Ci/gm)

Development of Cs specific glass matrix(Cs- 5 Ci/gm)

Sodium Borosilicate

Sodium Borosilicate

EVOLUTION OF GLASS MATRIX

0 100 200 300 400 500 600 700

1E-6

1E-5

1E-4

1E-3

0.01

Time (days)

Lea

ch R

ate

(g .c

m-2.d

ay-1)

Glass matrix

Leach rateXRD - Amorphous

EPMA - Homogeneity

Dr. C. P. Kaushik et. al.

Journal of Nuclear Materials

VITRIFICATION TECHNOLOGIES in INDIA• Induction Heated Metallic Melter

First generation melter technology

Tarapur & Trombay

Indirect heating using a metallic succeptor

• Joule Heated Ceramic Melter

Second generation melter technology

Tarapur & Kalpakkam

Direct heating using metallic electrodes

• Cold Crucible Induction Melter

Third generation melter technology

Trombay – inactive facility

Direct induction heating

WASTE IMMOBILIZATION PLANT, TARAPUR

1st Indian WIP (1995) Based on single hot cell concept View of hot cell & equipment

WASTE IMMOBILIZATION PLANT, TROMBAY

2nd Indian WIP (2002) Based on multi cell concept Remote welding of VWP

PROCESS SCHEMATIC FOR HLW VITRIFICATION

Induction heated metallic melter

INDUCTION HEATED METALLIC MELTER

Salient Features

• Multi zone heating concept

• Induction heated susceptor

• Secondary containment concept

• Radiation heating for process pot

• Freeze valve concept for pouring

• Remotely replaceable fill-head

• High Ni-Cr alloy as MOC (Inconel 690)

Incoming stream undergoes

Evaporation : 105 - 120 oC

Calcination : 300 - 700 oC

Fusion : 700 - 850 oC

Soaking : 900 - 950 oC

Pouring : 950 - 1000 oC

PROCESS DYNAMICS OF IHMM

WIP - Tarapur WIP - Trombay

Three main operating zones Four main operating zones

Rigid line cooler Remotely replaceable line cooler

Complete draining of the process pot Retention of glass plug in the freeze valve

Thermowell through process pot flange Thermowell outside the process pot flange

Power supply :

- Current fed inverter

- Constant frequency (1 kHz)

- Power control by varying voltage

Power supply :

- Voltage feed inverter

- Variable f 2 to 3 kHz

- Power control by varying frequency

INDUCTION HEATED METALLIC MELTER

• Partitioning of HLLW

• Recovery of Cs , Sr & Ru for societal applications

Recent Advances in WIP Trombay

HIGH THROUGHPUT METALLIC MELTER

Circular Geometry

Elliptical Geometry

Inductor

GlassGlass

Demonstration of Oblong Melter

Circular (15 LPH)

Oblong(30 LPH)

Skin effect

Induction heating

ADVANCED VITRIFICATION SYSTEM, S3F, TARAPUR

S3F, Tarapur Advanced Vitrification System (2006)

PROCESS DYNAMICS OF JHCM vs IHHM

Induction Heated Metallic MelterJoule Heated Ceramic Melter

Cold Cap

~ 80 % Coverage•Thermal shock•Bridging potential

JOULE HEATED CERAMIC MELTER

Salient Features of AVS – 1 & 2

• Effective heat transfer area: 0.36 m2

• HLW processing capacity: 10-15 LPH

• Maximum molten glass hold up: 125 L

• Maximum glass withdrawal: 42 L

• Number of freeze valves: 2 (JH x1 + IH x 2)

• U-shaped SiC plenum heaters: 15 x 2 kW

• High Ni-Cr alloy electrodes (Inconel 690)

• Overall size: 1.6 m x 1.6 m x 2 m

ADVANCED VITRIFICATION SYSTEM, S3F, TARAPUR

Advanced Vitrification System, Tarapur Electrode Firing Pattern

Thermally induced chaotic mixing

ADVANCED VITRIFICATION SYSTEM, WIP, KALPAKKAM

Salient Features

• HLW processing capacity: 15 - 20 LPH

• Maximum glass withdrawal: 80 L

• U-shaped SiC plenum heaters: 24 x 3 kW

• Non-contact method for glass pool level

Corrosion of AZS Corrosion of Inconel-690

Dr. C. P. Kaushik et. al.

Journal of Nuclear Materials

Ni Alloy 690 Glass

COLD CRUCIBLE INDUCTION MELTER for HLW VITRIFICATION

Solidified glass (Skull)

Finger (SS Tube)

Electric insulation (Alumina)

Salient features

– High temperature availability

– High waste loading possible

– Wider range of waste types

– Glass-Ceramics wasteforms

– Compact & Low hold-up

– Ease of decommissioning

In-Situ Skull Formation

Heat generation Coil current

Melt radius

Frequency

Heat loss Thermal conductivity

Thickness of skull

Dynamic equilibrium Minimise thermal losses

Stable operation regime

0.00 0.05 0.10 0.15 0.20 0.25

0

100

200

300

400

500

He

at

(kW

)

Thickness of the solidified layer (m)

Heat Loss

I1

I2

I3

I4

I1 > I

2 > I

3 > I

4

U

S

0.25 m

Design Aspects of Cold Crucible Induction Melter

Frequency selection

Electrical resistivity

Size of the glass pool

πμf

ρ δ

Diameter selection

• Type of feeding

• Calcine feeding: 200 kg m-2 h-1

• Liquid feeding: 100 L m-2 h-1

• 20 LPH: 500 mm Dia.

Model-based Design of Cold Crucible Induction Melter

Induction Heat

Temperature

Numerical simulation– Coupled Multi-Physics– Electromagnetic calculations– Hydrodynamic calculations– Thermal calculations

Model-based Design of Cold Crucible Induction MelterMinimize finger lossesMaximize melt power

Power Requirement of Cold Crucible Induction Melter

1/60 Model

Capacity : 20 LPH

Efficiency : 20 %

Power : 100 kW

Resistivity : 1 Ohm cm

Frequency : 200 kHz

Coil Turn : 1

Resistivity 1 Ohm cm 5 Ohm cm

Voltage 210 V 210 V

Power 100 kW 78 kW

Voltage

Power

275 V

130 kW

0 20 40 60 80 10010k

100k

1M

Basis: Crucible diameter = 4

1 Ohm cm 5 Ohm cm

Fre

qu

en

cy

(H

z)

Throughput (LPH)

High Resistivity Glass: Effect on Power Supply

Solid-Fed Cold Crucible (2006) Liquid-Fed Cold Crucible (2008)

Cold Crucible Induction Melting Facility, BARC

Electromagnetic coupling changes with glass level• Coil configuration, Glass level & Properties

0

50

100

150

200

250

300

350

600 700 800 900 1000 1100 1200 1300

T (OC)

z (

mm

)

Upper 110

Lower 110

Lower 130

Thermal Field inside the Cold Crucible Induction Melter

Start-up Feeding

Soaking Pouring

Different Stages of Melter Operations

Effect of feed rate on Cold Cap

Industrial Scale DemonstrationUsing High Temperature Glasses

• Glasses with High Na2O, Low B2O3 & High Tg offer radiation stability

• Al2O3/ZnO addition allows chemical and radiation durability to co-exist

Borosilicate glass containing Al2O3 Borosilicate glass containing ZnO

Na2O 24.29289

B2O3 12.02004

SiO2 45.23526

Al2O3 3.86776

K2O 0.374352

CaO 4.893022

TiO2 2.613253

Fe2O3 5.644995

MgO 0.233766

Cs2O 0.943333

Oxide Wt % VWP %

Na2O 23.222

B2O3 16.742

SiO2 39.519

ZnO 10.724

SrO 0.1453

Fe2O3 3.143

Fe2O3=UO2 2.5276

MnO 1.7167

BaO 0.4358

NiO 0.1321

MoO3 0.7923

Cr2O3 0.239

Cs2O 0.6603

Oxide Wt %

Industrial Scale DemonstrationUsing Borosilicate Glass containing Al2O3

• 1200 L Simulated Waste (Tarapur)

• 25-30 LPH (avg. 26 LPH 47 h) 100 kg Glass

• Cesium volatilization is 5.6 % at 1250 oC per Canister

Thermal Efficiency with Cold Cap90 kW for 25 LPH 28%

Industrial Scale DemonstrationUsing Borosilicate Glass containing Al2O3

Industrial Scale DemonstrationUsing Borosilicate Glass containing ZnO

• 1300 L Simulated Waste (Kalpakkam)

• 25 – 30 LPH (27 LPH in 50 h) 100 kg Glass

Borosilicate glass with Al2O3 Borosilicate glass with ZnO

Industrial Scale DemonstrationComparison of Melter Operations

• Start up operation: 2 hours

• 90 kW, 205 V, 900 A

• Start up operation: 5 hours

• 125 kW, 230 V, 1100 A

Summary and Road Ahead

Summary• India developed processes and methodologies for waste volume minimisation,

recovery of radionuclides and their deployment for societal benefits

• India successfully developed three generations of melters for vitrification of HLW

• Our experience in vitrification of HLW is comparable with best international practices

Road Ahead• Industrial adoption of Cold Crucible Induction Melter for vitrification of HLW

• Industrial scale demonstration of glass-ceramics to reduce waste package volume

IAEA Technical Meet onStrategies and Opportunities for the Management of

Spent Fuel from Power Reactors in the Longer TimeframeNovember 26, 2019

Thank You for the Kind Attention

Cesium-137

• Blood Irradiation

• Food Irradiator

• Sewage HygenizationHigh Level

Radioactive Liquid waste (HLLW)

Strontium-90

• Radio – pharmaceutical

Ruthenium-106

• Irradiation source and

for cancer treatment

Americium-241

• Neutron source

• Space application

Recovery of valuable radionuclides from HLLW for societal benefits

24/34

WEALTH FROM NUCLEAR WASTE

Cs-137 Glass Pencil Manufacturing Process

Production of 106Ru Plaque from HLW

HLWSeparation of residual

U & Pu

Separation of An, Ln &

Sr

Separation of 137Cs

106Ru waste

Silver substrate before and afterelectrodeposition

5-stage Mixer-Settler

Extractant : 0.1 M DCH18C6 in 50% octanol : 50% xylene Batch Size : 2.5 L Nature of Feed : 2 M Acidic Sr-90 in Feed: 4 mCi/lit % Extraction of Sr-90: 99.6%

90Strontium is used for milking of 90Y for radiopharmaceutical applications

SLM Generator

Recovery of Sr-90 from waste

Nuclear Fuel Power Reactor ReprocessingActinide

Separation

Fissile Material

Actinides

Immobilisation in Polycrystalline

Matrices

Fission ProductSeparation

Others Sr90 Cs137

Sealed Radiation SourcesFor Applications in Industry,

Agriculture, Medicine, Research.

Conditioning ofDisused

Radiation Sources

Disposal in NSDF

Deep Geological Disposal

Recycable

Non-recycable

IDEAL NUCLEAR FUEL CYCLE

Neutron SpallationFacility for

Actinide Incineration

Va

lue

Re

cove

ry

Velocity = f (Power)

Temperature = f (r, z)