Project of Decommissioning and Contaminated Water Management(Research and Development of Processing and Disposal of Solid Waste)

The Holistic Evaluation of Applicability of GeoMelt® ICV™ for
Treatment of 1F Water Treatment Secondary Waste
Fiscal Year 2021

December 5, 2022

Kurion Japan K.K.

VEOLIA NUCLEAR SOLUTIONSContents
1. Purpose
2. Implementation Schedule
3. Implementation organization
4. Features of GeoMelt® ICV™
5. Tasks for applying GeoMelt® ICV™
6. Relationship between the implementation contents / results of the previous
subsidy projects and the implementation items in FY2021
7. Implementation contents and results of the subsidy project in FY2021
7.1

Study on suppression of Cs volatilization in the final stage of melting

7.2

Engineering Scale System Modifications and Checkout Melt test

7.3

Engineering Scale Testing

7.4

Glass Formulation and Durability Testing

7.5

Investigation on the Applicability of GeoMelt®ICV™

8. Summary

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 22

1. Purpose
1) Holistic evaluation of applying GeoMelt®ICV™ technology as a method for stabilizing andimmobilizing a huge amount of secondary water treatment waste (spent adsorbent[zeolite, etc.], slurry and sludge) generated at the Fukushima Daiichi Nuclear Power
Station (hereinafter referred to as 1F) of Tokyo Electric Power Company Holdings, Inc.
(TEPCO), has been continued from the subsidy project up to last year.
2) In the subsidized projects up to last year, engineering-scale melting tests, glass
formulation / crucible tests, durability testing of manufactured glass, basic test on Cs
volatilization suppression, pre-conceptual design of treatment plant, etc. were carried out.
As a result, it was demonstrated that Cs emission during water treatment secondary
waste treatment can be reduced (Cs retention rate in glass was 97.22% to 99.44%), anda vitrified waste form with excellent durability was obtained.
3) In the subsidy project in FY2021, as the purpose of responding to the remaining
technical issues and improving the waste treatment process and gaining additional
improvement in Cs retention, test on Cs volatilization suppression at the final stage endof melting and an engineering-scale melting test using a melting test equipment that asintered metal filter is incorporated (including ALPS slurry dehydrate１ as simulated
waste), etc. is performed. Holistic evaluation of GeoMelt® ICV™ applicability is conducted,
including the results of past subsidy projects.
1： ALPS carbonate Filtercake and iron coprecipitate Filtercake were obtained by dehydrating ALPS
carbonate slurry and iron coprecipitate slurry by ATOX Co., Ltd., respectively.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 23

2. Implementation Schedule

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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3. Implementation organization

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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4. Features of GeoMelt ICV (1/2)

Electrode

Electrode① Glass melt and vitrification in the container (right)
Refractory• Supply and melt waste in the melting container.
sand• The molten glass is not needed to pour down from theRefractory sandbottom of the melting container. It is vitrified and kept
or Glass frit
Refractoryin the melting/disposal container.
container② The melting container and waste form are the same.
• The steel melting container used for melting treatment
Glass
is part of the waste form. (replace the melting container
for each batch)Steelcontainer③ Structure of melting container• The refractory container to store glass, refractory sandon the outside and a steel container on the outermost
side are installed.
④ Reducing the effect of melting on the refractory
container• Reduced heating time for refractory container due tobatch processing.
GeoMelt® ICV™ Container structure• Less corrosion of ICV container even when melting athigh temperatures.
⑤ High-loading waste can be melted due to high-temperature• Batch processing with GeoMelt® ICVTM can handle higher temperature operation (+1600℃), whichallows higher waste loading because a higher fraction of silica-rich zeolite can be included.
⑥ Co-treatment with zeolite or contaminated soil
• The waste loading in glass can be further improved by treating it at the same time as other 1F waste.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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4. Features of GeoMeltICV (2/2)⑦ Suppression of volatile Cs emission by cold cap management (figure below)• Emission of volatile Cs is suppressed by maintaining and managing the appropriate thickness of thecold cap (waste) on the molten glass.
• The volatilized Cs condenses within the cold cap at the top, then reincorporates into the molten glass.
• Since the cold cap becomes thinner at the end of melting, top-off frit (TOF) is added, volatilizing Cs iscondensed by the cold cap of TOF, and finally TOF helps further incorporate Cs.

⑧ Various range of melting capacity• The ICV can be selected according to treatment needs, with a track record of melting capacity from 100 kg to up to 50 tons.

Cold cap (waste)

Molten glass

TOF feeding

START

END

Operation Scheme of GeoMeltICV (cold cap management)
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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5. Tasks for applying GeoMelt®ICV™
Tasks to be examined for applying GeoMelt®ICV™, a vitrification technology, to secondary waste of 1F water
treatment were extracted. Since FY2017, these have been examined and resolved in the subsidy project.

A. Glass formulation１ ・Crucible test
① Setting the glass formation to make the glass durable according toeach waste composition. (Ongoing)② Setting of glass formation that enables increase of waste loadingin glass of ALPS slurry. (New)

B．Demonstration of operation method of Melter① Demonstration of good Cs emission suppression by the cold cap
management. (Ongoing)② Validation of suppression of Cs emission by TOF feeding at the
final stage of melting. (Ongoing)③ Demonstration of higher Cs retention by using a back-pulsing ofsintered metal filter in the off-gas treatment system. (New)

C. Quantitative elucidation of themechanism to suppress Csvolatilization① Quantitative understanding of Cs volatilization
behavior in the cold cap management. (Done)② Test on suppression of Cs volatilization at the
final stage of melting. (New)D. Glass durability test
① Confirmation of long-term chemical durability of the glass obtained by
the engineering-scale melting tests. (Ongoing)② Confirmation of possible effects of the refractory to the glass durability
in the disposal environment. (New)E．Applicability evaluation① Study and evaluation of facility concept including the melting container and its peripheral equipment (supply system, offgas treatment system, etc.) . (Done)② Investigation of applicability to actual treatment plant. (Ongoing)
1: Glass formulation is to combine wastes of various compositions and vitrify them, and the glass composition that satisfies the glass
performance is set from the result of the glass formulation.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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6. Relationship between the implementation contents / results of theprevious subsidy projects and the FY2021 implementation items (1/3)
FY2019～2020

FY2017～2018 1

FY2021

A. Glass Formulation・Crucible Test
Glass formulation・crucible test
• Of 1F water treatment
secondary wastes, 40 types ofglass blends are available formajor wastes.
• Understanding the glass
characteristics in the crucible
test.
→ Setting the glass formulation for
Melts 1 to 3

1: Kurion Japan K.K. received an orderfrom ATOX Co., Ltd. for FY2017-2018
test as part of the IRID program.

Glass formulation・crucible test
• Of 1F water treatment
secondary wastes, 12 types ofglass blends are available forwastes with a relatively small
amount.
• Understanding the glass
characteristics in the crucible
test.
→ Expanded the glass databasefor solidification of waste(Combined with the previous
fiscal year's implementation).
Glass modeling analysis• Evaluate the impact of changes
in waste composition.
• Evaluate the effect of reducing
glass produce amount whenmixing different types of waste.
• Evaluate the effect of different
melting treatment temperatureson glass produce amount,→ Confirmed superiority of
GeoMelt®ICV ™ (hightemperature treatment).

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

Glass formulation・crucible test
• Setting 10 types of glass blends
corresponding to the increase in
ALPS slurry content.
• Understanding the glass
characteristics in the crucible test
→ Setting the glass formation forMelt 12Note)• Melting test: See the next page forthe relationship between the glass
composition of 4 to 10 and the glass
composition of Melts 1, 2 and 3.
• The glass composition of Melt 11
was set by grasping the compositionof the ALPS slurry dehydrate.
96. Relationship between the implementation contents / results of theprevious subsidy projects and the FY2021 implementation items (2/3)

B．Demonstration of melt
operation (Engineeringscale melting test)
4 Electrode Square Melter

4 Electrode Square Melter Top-downMelt 4
KUR-EH +KUR-TSG＜Results＞・There is no difference in Cs retention
rate between Top-down and Bottom-up.

2 Electrode Rectangular Melter

Bottom-up

Melt 1

KUR-EH +ALPS carbonate・
iron coprecipitate slurry

FY2021FY2019～2020

FY2017～20181

Bottom-up
Melt 5
KUR-EH +ALPS carbonate・
iron coprecipitate slurry

4 Electrode Square Melter
Bottom-up
SMF (sintered metal filter) installed in off-gas
system.

Melt 9
KUR-EH +KUR-TSG
Melt 10
KUR-EH +KUR-TSG

Melt 2Melt 6

KUR-EH +KUR-TSG

KUR-EH +KUR-TSG

Melt 11
KUR-EH +ALPS carbonate・
iron coprecipitate Filtercake

Melt 3

Melt 7

KUR-EH +AREVA sludge

KUR-EH +AREVA sludge

Melt 12
KUR-EH+ALPS carbonate slurry＜Results＞• Cs retention rate 91.46 ～99.30%＜Task＞• Further improvement and stabilizationof Cs retention rate (due to there wasvariation in it)→ Test in a rectangular Melter witha small melting surface area.
Note) KUR-EH: Zeolite (glass former)
KUR-TSG: silicotitanate
1: Kurion Japan K.K. received an order fromATOX Co., Ltd. for the 2017-2018 test as
part of the IRID program.

＜Results＞• Improved and stabilized Cs retention rate withgood cold cap management（ 97.22％～99.44％）• The superiority of the rectangular melter could not
be confirmed.
＜Task＞• Improvement of Cs retention rate during TOF
supply process, optimization of operation

Melt 8

Soil +ALPS carbonate slurry<Results＞・ Demonstrated melting restart method
when melting is stopped for long period
・ Demonstrated using soil as a glass–former toreplace KUR-EH

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2(waste loading increased)＜Action items ＞• Operation optimization of TOF supply• Check the function of SMF• Treatment of ALPS carbonate・ironcoprecipitate Filtercake• Treatment of ALPS carbonate slurry with highwaste loading＜Results＞• Demonstrated the recycling of SMF captured
fine particles and the improvement of their Cs
retention rate (99.98-100.00%)• Demonstrated mixing, supply and treatment of
ALPS carbonate・iron coprecipitate Filtercake• Increased waste loading rate from 19.49% to29.46% of ALPS carbonate slurry
10

(Ref.) Comparison of 2-electrode and 4-electrode melter
4-electrode melter
Inside dimensions:43.2cm(L)×43.2cm(W)×43.2cm(H)Melt surface area: 1865 cm2

2-electrode melter
Inside dimensions:61.0cm(L)×21.6cm(W)×63.5cm(H)Melt surface area: 1266 cm2 (surface
area minus the area of the four corners)（Unit： cm）（単位）： cm

22

34

Graphite electrode

43

56

74
Graphite electrode

Graphite electrode

70
50

61

43

74

56

2-electrodes melter(Melts 5, 6, 7, 8)
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

4-electrodes melter(Melts 1, 2, 3, 4, 9, 10, 11, 12)11

6. Relationship between the implementation contents / results of theprevious subsidy projects and the FY2021 implementation items (3/3)
FY2019～2020

FY2017～2018 1

FY2021

C. Basic test / analysis on suppression of Cs emission at the end of melting• Quantitative understanding of Cs
volatilization behavior in cold cap
management: Test and analysis the insideof the melter as a 3-layer structure→ Understand the mechanism• Cs volatilization suppression research at
the end of melting: Test and analysis theinside of the melter as a 4-layer structure→ Reflect in the final stage of melting
operation after Melt 9• Long-term MCC-1 tests (365 days) for Melts
4 -8 glass. (Melts 4, 5 were completed.
Melts 6-8 got the data for 28days)→ Check durability.

• MCC-1 tests for Melts 6 -8 glass(365days)

D. Glass durability test
• Glass MCC-1 test2 for Melts1-3→ Check durability.

E. Applicability evaluation
1: Kurion Japan K.K. received an order from ATOX Co.,
Ltd. for the 2017-2018 test as part of the IRID
program.
2: Example of MCC-1 Test
・Teflon® transformation vessel
・Surface Area and Solution Volume ASTM Standard
No. C1220
・The specimen is about 14mm x 14mm x 1.5mm thick・The test vessel is Savillex (S/V) with a ratio of 10 m-1
・ASTM type 1 water (DIW water, > 18.0 MΩ cm)
・Tested at 90℃・Sample water was taken at 7, 14 and 28 days andanalyzed for major elements (Na, B, etc.) in the glass• Pre-conceptual design, various
evaluation reports↓• Present the overall features of the
facility where two 10-ton scale melters
are installed.
• Evaluate economic efficiency,
maintainability, etc.
<see previous page>• Results of engineering-scale melting
tests / basic tests up to FY2020

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2• MCC-1 test forglass in thepresence ofrefractory (28 days)• PCT tests for
Melts 5-7 glass• Applicability evaluation to actual
treatment plant< see previous page >• Results of engineering-scale melting
tests / basic tests in FY2021
12

7. Implementation items and contents of the subsidy project in
FY2021
7.1 Study on suppression of Cs volatilization in the final stage of melting① Investigation on the relationship between heating conditions and Cs volatilization at the end of melting including top-off frit (TOF).
② Analysis of the relationship between the temperature distribution of the 4-layer structure (TOF/waste mixture/calcinedlayer/molten glass) and the heat flux from the bottom

7.2 Engineering-Scale System Modifications
and Result of Checkout Melt
7.3 Engineering-Scale Testing① Test equipment modification: confirmation of specifications for
directly backpulsable and washable sintered metal filter (SMF)
installation in the first stage of the Melter off-gas treatment system.
② Evaluation of physical properties of simulated ALPS carbonate・ironcoprecipitate Filtercake. Confirmation test on transfer and supply
method.
③ Engineering-scale melting tests 9-12・ Validation of operations at the TOF supply processing stage(Reflecting the results of 7.1 ①)・ Capturing 99.98% of Cs in particulates released into off-gas by
SMF and then recycling to the Melter.
This improves the Cs retention rate in glass to almost 100%.
・ Melting test with test materials simulating the following wastes.
KUR-EH and KUR-TSG （Melt 9, 10）,
KUR-EH and ALPS carbonate ・iron co-precipitate Filtercake （Melt 11）
KUR-EH and ALPS carbonate slurry with increased waste loading （Melt 12）

7.4 Glass formulation・durability test
Glass formulation・crucible test

① Glass composition model update based on
evaluation data such as glass formation, crucible
test, viscosity, durability, etc.
Glass composition setting to increase thecontent of ALPS carbonate slurry.

Glass durability test
① Product Consistency Test (PCT) tests for Melts
5 - 7 glass samples② Effect confirmation test on glass by therefractory constituting GeoMelt®ICV™ waste
form under disposal environmental conditions③ Long-term MCC -1 tests for Melts 6 - 8 glass
samples

7.5 Investigation of GeoMelt®ICV™ applicability
Holistic investigation of the applicability of GeoMelt®ICV™ to solid wastes in actual treatment plant from a technical point of view
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information
7.1 Study on suppression of Cs volatilization in the
final stage ofmelting

Test on the relationship between heating conditions and Cs volatilization at the endof melting, including top-off frit (TOF) Test purpose: Since the amount of Cs volatilization at the TOF supply / treatment stage is relatively large

and the fluctuation in batch is not constant (unstable), the relationship of melting between
the waste mixture and TOF is grasped in order to suppress the Cs volatilization at the TOF
stage.
 Test contents:
 The tests to understand the relationship between heating conditions and Cs loss at the final
stage of GeoMelt® melting including TOF, and the role of TOF in suppressing Cs
volatilization are conducted.
 The waste mixture used in the tests:
KUR-EH＋ALPS carbonate・iron coprecipitate ｓlurry
KUR-EH＋KUR-TSG
 Regarding the accuracy of recovery of volatile Cs that evaluates Cs loss, recovery ofvolatile Cs and estimation of the state by TOF（Time Of Flight）-SIMS（Secondary Ion Mass
Spectrometry） are carried out.
 A computer simulation is conducted by performing a calculation (Ansys®) by the finite
element method (FEM) on the relationship between the temperature distribution and heat
flux of a 4-layer structure including the TOF that simulates the final stage of melting.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information

7.1.1 Relationship between Cs volatilization amount and TOF input amount(1) Melting of TOF/waste mixture in long silica glass cell
Silica glass cell (75φｘ300 mmH)
Waste mixture

hw0 =10 cm

Thermalinsulator

Movable stage

X0 cm
Before TOF
feed

hTF0 =10 cm
Thermalinsulator

TF= 12501350℃

After TOF
feed

Bundled thermocouples

Movable stage

X0 cm
↓(t1)
X1
↓(t2)
X2
↓(t3)
X3

Melted TOF/
Molten wastes

Ts
Thermalinsulator

TF= 12501350℃

Silica glass cell (75φｘ300 mmH)
TOF feeding on
Waste mixture
when Ts0=150℃.

Ts0

TF=12501350℃

Laminationin the cell
• TOF
• Waste mixture• Calcined layer• Molten glass

Bundled thermocouples

Thermalinsulator

X3 cm

Movable stage

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

TF= 12501350℃

Y cm
X3 cm

Movable stage

15

(2) List of melting parameters

Parameters

Kurion Japan Confidential Information

Definition

Typical values

hW0 (cm)

Initial height of waste mixture filled in the cell

10

hTF0 (cm)Height of ASG-FRIT (TOF) fed on waste

10

TF (℃)

Operating temperature of furnace

TS0 (℃)

Temperature of waste mixture surface atwhich TOF is started to fed on wastes

TS (℃)

Surface temperature of TOF monitored by TC

Xi (cm)Cell length projected into furnace. i =0; theinitial value. i =3; final

2 (i=0), 4 (i=1),
6 (i=2), 8 (i=3)

Y (cm)

Estimated surface level from the furnace
ceiling;

1 (when hW0=10,
hTF0=10)ti (min)

Duration time for each i

2 (i=1), 2 (i=2),2 (i=3)

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 21250~1350
150

16Kurion Japan Confidential Information(3) Off-gas analysis

Condenser

 After finishing the experiment,
clean the glass equipment.

Laminationin the cell
• TOF
• Waste mixture• Calcined layer• Molten glass

 The off-gas generated during
melting in the temperature
gradient electric furnace iscondensed by a water-cooled
condenser.

Thermalinsulator

X cm
1250-1350℃

Movable stage

 Condensed water and washwater are analyzed by ICP-MS
to determine the total amountof Cs from molten waste.
Glass equipment for trapping Cs (Aset of glassware above the green line)
ICP-MS analyses of melted glass
samples are also carried out toevaluate Cs concentration inside.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Japan Confidential Information(4) Protocol of Monitoring of surface temperatureKurionandTrap of Csfrom materials

 Monitoring of Ts
MELT6-15%, -20%Water, weight : 330-350 g for hW0=10 cm
MELT5-10%Water,
weight : 285-305 g for hW0=10 cm
TF=1250℃, 1300℃, 1350℃
TOF
weight : 520 g for hTF0=10 cm
TF=1350℃
TOF
weight : ~520 g
for hTF0=10(3/3), 6.7(2/3), 3.3(1/3), 0(0/3) cm

 Trap of Cs from materials







Test condition and protocol was same as in the experiments for monitoring Ts
Glass equipment for trap of Cs was settled on the silica glass cell just after
TOF was fed on MELT6-15%, -20%Water, MELT5-10%Water at Ts>150℃.
Stage(silica glass cell) was moved downward, X=2cm→8cm by 2cm step
every 2 min, and kept for 1 h after TS shows const.
Glass equipment was washed by pure water, and Cs in water was analyzed
by ICP-MS.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information(5) Waste mixture and TOF melting test
MELT6-15%Water+3/3TOF@1350℃

1400

Tbottom=~1380℃

1300
1200
1100

TS=~1140℃

Temperature（oC）

1000
900
800
700

Subsidenceof TOF layer

600
500
400

Insertion of TC for bottom

300
200
100
0
0

10

20

30

40

50

60

70

80

90

100

Time （min）

Waste mixture and TOF melting test
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information(6) List of data related to Cs loss generated and trapped from waste mixture
Experiment

TF (℃)T S (℃)Cs from waste (%)

Tbottom (℃)

MELT6-15%Water+3/3TOF

1350

1140

1390

0.08

MELT6-15%Water+2/3TOF

1350

1170

-

0.63

MELT6-15%Water+1/3TOF

1350

1300

-

2.08

MELT6-15%Water+0/3TOF

1350

1300

-

3.59

MELT6-15%Water+3/3TOF_2nd

1350

-

-

0.22

MELT6-15%Water+2/3TOF_2nd

1350

-

-

0.43

MELT6-15%Water+1/3TOF_2nd

1350

-

-

2.08

MELT6-15%Water+0/3TOF_2nd

1350

-

-

3.45

MELT6-20%Water+3/3TOF

1350

1141

1363

0.30

MELT6-20%Water+2/3TOF

1350

1240

-

1.32

MELT6-20%Water+1/3TOF

1350

1287

-

2.93

MELT6-20%Water+0/3TOF

1350

1304

-

4.98

MELT5-10%Water+3/3TOF

1350

1135

1352

0.08

MELT5-10%Water+2/3TOF

1350

1248

-

0.17

MELT5-10%Water+1/3TOF

1350

1284

-

1.14

MELT5-10%Water+0/3TOF

1350

1302

-

7.54

MELT5-10%Water+3/3TOF_2nd

1350

-

-

0.10

"-": Indicates that each temperature was not measured
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information(7) Relationship between Cs loss and surface temperature Ts

1320

8

Melt5-10%

1300

Melt5-10%

Melt6-15%

7

Melt6-20%

1280(Left)
When the amount of TOF
decreases, the heat transfer
increases and the surface
temperature rises. The way
the surface temperature rises
differs depending on thechemical composition
including the water content of
the waste.

Melt6-15%
Melt6-20%

51240

Cs loss (%)

Surface temperature (oC)

6
1260

1220
1200

4
3

1180
2
1160
1

1140
1120
0

0.5

1

0
1100

TOF volume ratio （10cm height）

Relationship between TOF volume
ratio and surface temperature

1150

1200

1250

1300

1350

Surface temperature (oC)

Relationship between surface
temperature and Cs loss%

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2(Right)Regardless of the water content,
Melt 6 gradually increases thevolatilization amount of Cs as
the surface temperature rises,
but Melt 5 behaves so that thevolatilization amount increases
significantly when thetemperature exceeds 1250℃.

21(8) Relationship between Cs loss% and TF, Ts
and TOF volume ratios
8

4

MELT6-15%water with no TOF
3.5

y=0.021x-23.84

2.5

TF

2

y=0.019x-22.05
1.5
1

1130℃

0.5

1160℃

0
1100

1200

＊

1300

1400

TF and TS (℃)

Relationship between Cs loss%
and TF and TS(Right)MELT6-15%water 1st  Cs emission from
MLET5-10%Water
MELT6-15%water 2nd
melting process was
MELT6-20%water
reduced to the same
MELT5-10%water
low level as that of6
Cs loss (%)

Cs loss ( %)

7

TS

3

Cs emission @TF=1350 ℃

Kurion Japan Confidential Information

5

MELT6 mixtures bycovering with 10cm
TOF.

4
3

 However, the thinner2
TOF of melt test 5
0.30%
0.22%
showed higher Cs
0.08%
1
volatilization than melt
0.08%
test 6, probably due to0
the difference in melt
0 0.2 0.4 0.6 0.8 1 1.2 1.4
properties (composition,
TOF volume ratio (10 cm height)
melt properties, etc.).
Relationship between Cs loss% andTOF volume ratio

Zero Cs loss* when there is no TOF layer is achieved at a furnace operating temperature TF of
about 1150℃ or less or a waste mixture surface temperature Ts of 1130℃ or less, but when TF
is heated to 1150℃ or more or Ts is 1130℃ or more, volatilization of Cs is accelerated.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

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Kurion Japan Confidential Information(9) Summary
Relationship between of Cs volatilization and TOF feed amount (1/2)

 Melting of the TOF involves the downward ' subsidence ' of the TOF layer on
the waste mixture due to large void formation (60-70% volumetric shrinkage)caused by the melting of the waste mixture.
 Subsidence of the TOF layer causes the release of the gas phase containedin the voids. This could be a route for discharging Cs from waste.
 From the relationship between the measurement result of the surface
temperature TS and the subsidence of the surface layer, it is necessary to
add TOF before the evaporation of the water on the surface layer iscompleted.
 This allows TOF to sequentially fill the voids formed during melting of thewaste mixture, allowing the process of melting the waste mixture at hightemperatures to proceed at the bottom of the TOF rather than at the surface.
 Insufficient TOF coverage presumes that waste will melt on the free surface
and induce Cs volatilization above 1130 ℃.

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23

Kurion Japan Confidential Information(9) Summary
Relationship between of Cs volatilization and TOF feed amount (2/2)

 TS>1100 ℃ is necessary to complete melting of TOF and mixing with melted
wastes. As a result, smooth glass surfaces were formed after cooling to RT.
 Cs volatilization from wastes under TOF(hTF0=10cm) was ~0.3% of total Cs inwastes using maximum TF(=1350℃).
Thinner TOF layer on wastes increased Cs volatilization.
Trend of Cs volatilization as a function of TOF volume depended on thewastes powder (probably, water content and the chemical composition of
constituents).
 From the viewpoint of the viscosity of the melt, the mixing of the molten waste
mixture and TOF is accelerated when the liquid properties (viscosities) are at
the same level, so it is desirable to keep them at T>1100 ℃ with the same
viscosities. At the same time, if mixing proceeds by convection, the ideal
operation is to satisfy the surface temperature TS < 1130 ℃ to suppress Csvolatilization.

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24

Kurion Japan Confidential Information
7.1.2 Recovery accuracy of volatilized Cs and assumptionof substance(1) Off-gas analysis (Cs trap and analysis)

 Measured by inserting a silica glass
substrates to check the Cs recovery
accuracy.
Condenser
Silica glass substrates
Laminationin the cell
•
•
•
•

TOF
Waste mixture
Calcined layer
Molten glass

Thermalinsulator

X cm
1250-1350℃
Movable stage

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 Off-gas generated during melting
in a temperature gradient electric
furnace is condensed in a watercooled condenser.
 A couple of clean silica glass
substrates are placed in thetrapping glass tube, and collected
after finishing the experiment.
 The background measurement
substrate is cleaned by
performing the same treatment
as the Cs trap test.
 Both substrates will be analyzed
using TOF-SIMS, which analyzes
the elements on surface with highsensitivity.

25

Japan Confidential Information(2) TOF-SIMS spectrum of substances trapped on Kurion
silicaglass
substrate surface (positive charge)

The signal due to the Cs ion having a mass number of
133 is clearly observed, and the signal of the target
Cs is obtained.

(CPS)

TOF-SIMS spectrum collected from silica glass substrate
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26

(CPS)

(CPS)

(CPS)

Kurion Japan Confidential Information(3) TOF-SIMS spectrum collected from the substrate(positive charge)

Observation of alkali elements
coincides well with XRD dataon the next page.

Collection yield of Cs=96.1%(Top) Unused substrate, (Center) Substrate before washing, (Bottom) TOF-SIMS
spectrum (positive charge) collected from the substrate after pure water cleaning
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27

Kurion Japan Confidential Information(4) TOF-SIMS spectrum collected from the substrate(negative charge)
Intensity (CPS)

1600000
1400000

Silica_nega

1200000
1000000
8000006000004000002000000

020Intensity (CPS)

1600000

40
35Cl

1400000

60

m/z

80

100

120

140

BOB
Non-washing_nega

1200000
1000000

Elimination of B, Cl, S from melt

80000016O

60000037Cl

BO240000020000032S16O2

32S16O
3

SrO

0

Intensity (CPS)

1600000

0

20

40

60

m/z 80

B, Cl, S (of which B and S are oxides) wereobserved, and alkali borates and sulfates collatedwith the positively charged TOF-SIMS spectrum
results were also identified by XRD analysis on
the next page, it is thought that they werevolatilized and collected together with these.

1400000
1200000
1000000
800000600000400000200000

100

120

140

Washed_nega

Volatile Cs would be eliminatedwith BOx, Cl- and/or SOx.

0

0

20

40

60

m/z 80

100

120

140

(Top) Unused substrate, (Center) Substrate before washing, (Bottom) TOF-SIMS
spectrum (negative charge) collected from the substrate after pure water cleaning
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 228

Japan Confidential Information(5) Powder X-ray diffraction pattern of the sample Kurion
collected
from theinner wall of a silica glass cell
SampleTincalconite

Intensity (cps)potassium sodium sulfate(VI)10 Eliminated and trapped materials from
MELT6-15%water+2/3TOF@1300 ℃ werecollected on paper filter and analyzed bypowder XRD.
 Diffraction lines from Na2B4O7・5H2O andK1.43Na0.57SO4 were observed.

20

30

40

2θ (°)

50

60

70

80

Powder X-ray diffraction pattern of the sample collected from the inner wallof a silica glass cell

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Kurion Japan Confidential Information(6) Summary
Recovery accuracy of volatilized Cs and assumption of substance Since more than 96% of Cs trapped on the inner wall of the glass
instruments can be washed into the collected water for ICP-MS, it can bemeasured with sufficient reliability as a measurement of the amount of Cs
volatilization.
 TOF-SIMS data revealed that Cs was emitted from the waste on heatingwith alkali metal, B, S and Cl.
Although the volatile form of Cs is unknown, it is conceivable that alkali
volatilize as boric acid, sulfuric acid or hydroxide and are flown together.
 This TOF-SIMS analysis technique would be used for stacking of emitted
materials as function of time qualitatively, but not applied for qualitative
measurement at the present due to a large vapor pressure of H2O.
 Possible forms are borates, sulphates, chlorides, hydroxides, or metal
vapors.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 230

Kurion Japan Confidential Information
7.1.3 Analysis of the relationship between the temperature gradientof the melt andthe heat flux by simulation using FEM(1) FEM simulation model of melting process of TOF/ Waste mixture

Boundary conditions and thermal conductivity are given to the hierarchical structure in
the container formed by the mesh, and the temperature profile is reproduced.
Heat fluxq (W/m2)

12
layer

Thermal conductivity
λj (T) (j=1-12)

Diameter: 70 mm
Height: 60 mm(Thickness of each
Layer: 5mm)
The calculation consists of 12 layers (Layer
0-11).
Layer 0: Assuming a constant temperaturein the lower molten layer.
Layer 11: The layer in contact with the air at
the top.

Side wall(thermal insulator)

Temperature of bottom
Tbottom = 1350 ºC (const.)

Parameters given to the each component and basic
condition for thermal conduction in the model

FEM simulation model composed of 12
layersMETI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

Parameters, λj and q, are set up to simulate temperature
profile and compare with experimental results.
31

Kurion Japan Confidential Information(2) Model of thermal conductivity- Maxwell-Eucken model -The Maxwell-Eucken model is applied because it is a structural model that can bestreflect the actual aspect from the observation of the cross-sectional structure of the meltby the melting test.
λc: Thermal conductivity of continuous phase
λd: Thermal conductivity of the dispersed phase
εp: Volume fraction of gas phase

/
/
Bulk

PowderGlass

Bubble dispersion
model Continuous
phase: solid

Air
10

Glass

Glass particle fillingmodel Continuous
phase: air

Air
10

Volumefraction εp
Porosity ε :Volume fraction εp

Porosity εp :

1

0.8
0.9

0.1

1 (Air)0.01

250

Heat conductivity (W/(m•K))

Heat conductiviy (W/(m•K))p0 (Silica sand)
0.1
0.2
0.3
0.4
0.5
0.6
0.7

0 (Silica sand)
0.1

1

0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1 (Air)

0.1

0.01

450

650
850
Temperature (K)

1050

250

450

650
850
Temperature (K)1050

Temperature dependence of λEucken and εp for each model
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32

Kurion Japan Confidential Information(3) Thermal conductivity value of various borosilicate
glass melts formodeling

The temperature dependence of thermal conductivity differs between the
low and the high temperature region, and the boundary is the glasstransition temperature Tg. In the temperature range of T <Tg, it shows alarge temperature dependence, changes linearly, and the higher thetemperature, the higher the thermal conductivity. In the temperature range
of T> Tg, the temperature dependence is very small and is almost constant.
600 ºC

Thermal conductivity (W/m・K)

Thermal conductivity (W/(m・K))

1.8
1.6
1.4
1.2
1
0.8
0.6

300

500

700

900

1100

1300

1500

In the modeled temperature dependence,
Tg is set to 600ºC, and it is expressed
as a function (a × TºC + b) that
thermal conductivity changes linearlywith respect to T before and after that.

1.8
1.6
1.4
1.2
1
0.8
0.6
0

200

400

600

800

1000 1200 1400

Temperature (K)Thermal conductivity data collected from the glass
database InterGrad®

Temperature (ºC)
Simplified temperature dependence of thermal
conductivity of borosilicate glass melt

Thermal conductivity of borosilicate glasses(Ref.: from glass database, InterrGrad ver.8.0)

λ will be set up in this experimental dataregion to fit the measured temperature
profilesNote: Plots are color-coded according to differences inglass composition in the database
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33

Kurion Japan Confidential Information(4) Model calculation using conductivity data of glass melt (1/2)

The effects of each factor of thermal conductivity, void ratio, and heat flux on the simulation by FEM areconfirmed, and the measured temperature gradient is reproduced based on the calculation results. The resultsof confirming the effects of each factor are shown in ① to ③ below, and ④ to ⑥ are shown on the next page.
Bottom

1-6th

7-12thSurface

1400

1400
1200

1100

low l

SurfaceTemp.
991 ºC944 ºC895 ºC

1000
Heat flux at surface＝10 kW/m2

900

1000

Heat flux(W/mm2)

High l

1200

Surface temp.(ºC)

Surface Temp.(ºC)

1300

800
600
400
200
0
0

800

0

20
40
Position z (mm)605000 10000 15000 20000 25000 30000

Heat flux at surface(W/m2)

Thermal conductivity（W/m/K）

①

②

③

• Temperature gradient obtained
assuming two types of glass(thermal conductivity: high λ, low λ)• Ts changes by changing the heat
flux in a system in which two
different glasses are laminated.

• The higher the thermal conductivity,
the higher the surface temperature.

• Since the measured Ts is 1150ºC or
higher, it is estimated that the heat
flux is in the range of about 5 kW/m2.

• Since the actual thermal
conductivity data of glass is b> 0.65,
the condition that the surface
temperature is close to the actual
measurement is predicted to beheat flux q> 3.0kW/m2(0.003W/mm2).

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34

Kurion Japan Confidential Information

l=0.75

Low

Void
ratio

l=0.40

High
300

800

Temperature (℃)

1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0

Temperature (℃)

Thermal conductivity (W/m/K)(4) Model calculation using conductivity data of glass melt (2/2)

1300

Temperature (K)Thickness of glass (mm)

⑤

④

•

The temperature change ofEucken when the porosity εp ischanged is shown.

•

It can be seen that when εp islarge, the conductivity decreases
and it becomes adiabatic. The
calculation uses the apparent
thermal conductivity of each layer,
the interpretation of which mustreflect the actual structure of thematerial.

••

Thickness of glass (mm)⑥

A linear profile is obtained bychanging λ from 0.4 to 0.75 inincrements of 0.05, and Ts is 503
to 688ºC. The heat flux is fixed at
0.01 W / mm2.

•

When one layer containing
bubbles is inserted, bending
appears in the temperature
distribution.

•

When the insertion of layers
containing bubbles is gradually
increased, the temperature
gradient becomes steeper as thenumber of insertions increases.

•

When everything contains a foamlayer, there is no difference, but
this is because Ts is constant.

In order to adjust Ts to themeasured 1100 to 1140ºC, it isnecessary to reduce the heat flux
q to about 0.003 W/mm2.

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Kurion Japan Confidential Information(5) Measurement method of the temperature gradient Measurement of temperature gradients of melting MELT6-20%Water/TOF(3/3) at TF=1350℃
Thermocouple in a glass tube

 Measurement method
Thermocouples (5 in total) are placed in eachlayer of TOF / waste mixture in MELT6 andheated in an electric furnace in the samemanner as in the Cs emission experiment.

TOF

T.C Position
TC5 (8cm)

Silica glass container (75φｘ300 mmH)
TOF
Waste mixture

Dried &calcining
waste mixture
Thermalinsulator

TC4 (6cm)
TC3 (4cm)

X cm

1250-1350℃
Movable stage

TC2 (2cm)
Molten glass

TC1 (0.4cm)
Temperature measurement in glass tube

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Kurion Japan Confidential Information(6) Measured temperature data
1600

Simulated temperature range

1400

Temperature (℃)

1200
1000

Dimensions from thebottom of the cell

800

0.4cm
TC1=Bottom(4mm)

TOF supply
1/3

600

TC2=2cm
TC3=4cm

TOF supply
Rest 2/3

400

TC5 was moved up to thesurface level (10 cm) tomeasure TS

TC4=6cm
TC5=8cm

200
0
0

20

40

60

80

100

120

140

160

Time (min.)Measured temperature trace for temperature profiling of the material in the cell
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Kurion Japan Confidential Information(7) Temperature simulation at final stage of melting using FEM

1600

2

1.6
1200

Tem perature(℃)/ oC
Temperature

1.4
1000

1.2

800

Simulationof temperature
Run
19

1

Measured profile

0.8

Thermal conductivity

0.6

gradient

600
400

0.4
200

0.2

0

0
0

2

4

6

8

10

12

Height (cm)/ cm
HeightSimulated temperature profile for height from the bottom of
the cell
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Therm
al conductivity
conductivity(Wm/W -1mK-1-1)K -1
Thermal

1.8

1400⮚ Thermal conductivity dropped
sharply at a height of 7 cm from thebottom. This corresponded to thelevel of the interface between themolten waste mixture and the TOF.
⮚ The molten TOF above this level ishighly transparent and has a large
effect of radiant heat transfer.
Therefore, it is considered that theheat energy is dissipated by theradiant heat transfer, so that theheat energy transferred by the
conduction heat transfer is lowered
and the actual surface temperature
is lowered.
⮚ Therefore, even if the molten waste
mixture (opaque) is higher than
1300℃ in the lower region about 34 cm below the top surface, thetransparency of the molten TOF
keeps the top surface temperature
at Ts < 1150 ℃. This satisfies thesurface temperature condition(Ts<1130 ℃) that ℃ suppresses Csvolatilization.
⮚ When sufficient TOF is not filled, its
heat conduction is conduction heattransfer, and the surface
temperature has to be high in orderto maintain the heat flux, forming astate in which Cs volatilization is
likely to occur.
38

Kurion Japan Confidential Information(8) Temperature profile in melting waste layers at early stage

2

Simulated
Temperature profile

1200

This blue-shaded region might contain thelayer composed of un-melted materials andothers, so must be excluded from theevaluation.

1.8
1.6

Temperature (℃)

1000

 Lower thermal conductivity values
have to be used to adapt themeasured temperature profile. Thisdrop of thermal conductivity is causedby the forming (bubble layers) as
found in the direct observation.
 Void ratio~0.5 is reasonable value
taking into account the shrinkage of
wastes mixture 60~70% in volume
during melting.

Thermalconductivity

800

1.4

600

400

1.2
1
0.8
0.6
0.4

Void ratio

200

0.2
0

Thermal conductivity ( W m-1 K-1) or Void ratio (-)

1400

0
0

2

4

6

8

10

Height (cm)

12

14

16

18

20

Simulated temperature profile for measured data corresponding to theheight above the bottom of the cell
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

39

Kurion Japan Confidential Information(9) Summary - Analysis of the relationship between melt temperature gradient andheat flux by simulation using the finite element method (FEM) The temperature gradient around the surface of the molten glass depends on the heat
conduction mechanism due to the balance between heat diffusion (conduction heattransfer) and heat radiation (radiation heat transfer). This gradient changes dependingon the thickness of the TOF. The thinner the TOF, the gradually decreases and thehigher the TS.
 In lab-scale experiments, the convection of the melt during melting was very weakcompared to the engineering scale tests. The transparent TOF covers the opaquewaste mixture, and convection and mixing of these must occur after their melting iscomplete and viscous flow occurs.
 A 12-layer model was formulated for FEM simulation of steady-state heat transfer toobtain the final molten temperature profile of the molten TOF layer/waste mixture layer.
The FEM simulations show good agreement with the measured temperature profiles
using appropriate thermal conductivity values.
 Melted TOF layer on molten waste mixtures might have lower apparent thermal
conductivity because of its high optical transparency (high ratio of radiant heat transfer
to conduction heat transfer).
The Maxwell-Eucken model incorporates a void factor and is therefore suitable forsimulation of layers containing foam layers (early stage).

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 240

7. 2 Engineering-Scale System Modification and Checkout Melt
(1) Purpose and Method Purpose and method of Engineering Scale System Modifications
Purpose:••Added a Sintered Metal Filter (SMF) for Cs recovery.
Improved IR Camera for monitoring melting conditions and Viewing Window.

Method:•••Increased strength by enlarging the dimensions of the outer steel vessel of the melter to support
the weight of the SMF.
Installed heat tracing and insulation to prevent condensation of moisture in the off-gas due totemperature drops in the SMF and off-gas piping and equipment.
Prevented the sticking of supply test materials (waste + glass frit) with dew in supply equipment
and piping due to the temperature rise by heat tracing etc.

 Purpose and method of checkout melt
Purpose:• Check the operation of the equipment modified parts. Perform checkout melting to confirm
optimal implementation of SMF back-pulse. Confirmation of modified melt test preparation
methods, training of test operators.
Method (Check out the new melt processing test procedure):• In preparation of melt, load base frit and install starter path.
• Transfer melter to melting position, set off-gas hood, then install electrodes remotely andconnect them with starter path (Corresponding to the procedure assumed in the actual
treatment plant.).
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 241

(2) Modification part of Engineering-Scale System#
Component
Items Changed
ReasonFeed pipe – Increased size from 3” to 4” Diameter
To prevent feed sticking and match larger SMF filter inlet pipe
① HoodOutlet Pipe – Increased size from 3” to 4”
To minimize particulate carryover and to match larger SMF filter inlet② HoodFront Hatch/Window – Increased size by 10%
To aid in melter system preparation and setup③ HoodModification of Mount and windows for new IR camera To better match new IR Camera matching surface④ HoodMelt Box perimeter flange dimensions increased
To match new larger hood dimensions⑤ Melting Container
Melter to SMF increased size 3” to 4”
To match larger SMF filter inlet⑥ Off-gas Pipe
Cloth Bag House filter replaced by SMF
Change to SMF make off-gas system more efficient and compatible with PCD⑦ First Stage Filter
To match new off-gas pipe size
⑧ First Stage Filter Bypass Bypass line diameter increase to 2” to 4”
Replaced off-gas fan with new larger fan
Larger VNSFS fan installed to better match SMF requirements⑨ Primary Blower
Replaced off-gas backup fan with larger fan
Larger VNSFS fan installed to better match off-gas system⑩ Backup Blower
Stack
Off-gas
Pipe
Increased
fanoutlet
pipe
from
2”
to
4”
Allowsincreased flows of new off-gas system⑪
With the removal of the cloth baghouse filter and the change in the flow rate due to the installation of the SMF, mainly the dimensions of the off-gas piping
and the blower capacity were changed.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 242

(3) Configuration of modified Engineering-Scale Melting Test
Apparatus
Heat tracing applied to the off-gas system and SMF filter
to ensure condensation does not occur on pipe walls
Final configuration of ES System during Checkout Meltwith SMF and the off-gas piping insulation applied

Before Off-gas System was Insulated

System during Checkout Melt
Melter Preparation

The new melter configuration placing under the off-gas hood
(Adopts a steel container with dimensions that allow expansion of therefractory container)

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 243

(4) Checkout melting results (SMF operating status)
Purpose: Confirm that the clogging of
cartridge (filter element) is removed
and cleaned by the back-pulse.

Results:
 It was confirmed by recovery of thedifferential pressure and goodcleanliness inside the SMF that thesimulated clogging (coating) could
be removed by the back-pulse.
SMF Clean Interior with New Cartridges(Clean cartridge differential pressure before
test start: 1.5)

SMF Clean Cartridge after Back-Pulsing,after Melt
(Differential pressure when filtering cartridgeby the back pulse: 1.5 (return))

SMF Cartridge with DE Coating
before Checkout Melt
(Differential pressure when
coating cartridge: 4.0)

SMF Clean Wall after Checkout Melt

FilterTest
Condition

Differential
Pressure(Inches H2O)

①
②
③

1.5
(=3.73 mbar)
4.0(=9.95 mbar)
1.5(=3.73 mbar)

Differential pressure before and after
operation (Confirmed that the differential
pressure can be returned to thereference pressure by the back-pulse.)

Conclusion: The SMF operated as designed during the Checkout Melt proving it was ready for Melt Tests.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 244

(5) Checkout melting results (screw auger, IR camera/sight glass
operating status)

No feed materialbuildup on auger
tube or feed pipe
walls.
Inside feed pipe and auger outlet after Checkout Melt
(downward view from upper)

Feed pipe outlet inside the refractory container after
checkout melting (upward view from the bottom side)

Inner refractory container
can be viewed boththrough side window andwith IR camera.
The conditions inside therefractory container are
the same, but they do notlook exactly the same
because the viewing
angles are different.

2 hours after the start of melting viewing through hood window

2 hours after the start of melting viewing through IR camera

Conclusion: Feed piping stayed clean and the ability to view the melt was proven during Checkout.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 245

(6) Summary of modification of Engineering-Scale System andresults of checkout melt
Confirmation Item

1. Verify operation ofSintered Metal Filter

Result① SMF‘s monitoring and operation system works as designed. Specifically, the set temperature of the SMF
was 100℃ or more (design limit of 300℃), the same as the off-gas piping, and the design limit of thedifferential pressure is 20inH2O, which was monitored by the SMF monitoring and operation system. The
duration of the back-pulse was measured by the control system and was 0.3 seconds. In addition, the backpulse frequency is automatically set by the monitoring and operation system.
② It is confirmed that the differential pressure was returned to the reference pressure by the back-pulse. (Referto page 44: Differential pressure change by test)③ Good cleanliness of the filter element (SMF cartridge) was confirmed by observing the inside of the filter
housing after melting. (See page 44: State of SMF internals and cartridges for each test)

2. Prevention ofcondensation in SMF
and off-gas① Heat tracing with insulation worked as designed, maintaining off-gas piping and filter assemblies at or above
100 ℃ at all times, ensuring no condensation in the off-gas system throughout the test
② Inlet heater maintained the melter plenum above condensation point at all times as verified by visual andelectronic (local and SCADA) indications.

3. Prevention of sticking infeed device for test
materials (waste + glassfrit) and pipes, etc.

① The temperature of the plenum of the melting container can be maintained above the dew point by means ofan inlet heater that heats the air supplied to the melting container, which also contributes to the prevention ofcondensation in the off-gas piping.
② It is confirmed that the occurrence of condensation in the off-gas system could be prevented throughout the test.

4. Verification of
Improvement of process
viewing (IR Camera,
window)① The IR camera works without problems in the entire process temperature range from the start of melting to
the end of melting. Process operation monitoring is improved with the increased resolution and improved
viewing window.
② By calibrating using a melt thermocouple, it is possible to calibrate the emissivity value for more accurate
temperature display.

5. Verify the revised
procedure of melt
preparation procedure① In preparation of melt, load base frit and install starter path.
② Transfer melter to melting position, set off-gas hood, then install electrodes remotely and connect them withstarter path. Successful melt processing preparatory work according to the new procedure.

Conclusion: The new Engineering-Scale System checked out and was proven “ready for use” for the Melt tests.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

46

7.3 Engineering Scale Melting Test
(1) Purpose and MethodEngineering scale Melts 9-12 performed in FY2021 following engineering scale melts 1-8 done by FY2020.

Common purpose / method among 4 engineering scale melt tests• Demonstrate melt treatment with engineering scale (waste 180 kg treated in each melt test)• Verify and evaluate the operability and performance of Sintered Metal Filter (SMF) installed by test systemmodification.
• Measure quantitatively and evaluate the release of Cs and Sr by stack sampling.
• Apply and evaluate the findings obtained from Tokyo Tech study for operation at the final stage of melting.
• Grasp the homogeneity of Cs distribution in glass by sampling glass after melt.

Specific purpose/method for each melt test.
• Melt 9： Treated waste is KUR-EH+KUR-TSG. Particulate captured by SMF is not recycled to melter but recovered tomeasure the amount of particulate and Cs concentration.
• Melt 10： Treated waste is KUR-EH+KUR-TSG, same with melt test 9, but with higher water content (15→20%) todemonstrate treatment with high water content.1
Particulate captured by SMF is recycled to melter during melting operation.
• Melt 11： Treated waste is KUR-EH+ALPS carbonate・iron coprecipitate Filtercake. This dehydrate product is asimulated ATOX product. Transportability and feeding of the waste is verified by fundamental test prior tomelt test. Particulate captured by SMF is recycled to melter during melting operation.
• Melt 12： Treated waste is KUR-EH+ALPS carbonate slurry. Melt test 1, 5 are ALPS carbonate・iron coprecipitate
slurry, but this test is with higher loading rate of carbonate slurry (content of MgO in waste) formulation.
Particulate captured by SMF is recycled to melter during melting operation.
1: Purpose of demonstration of melting waste with high water content:
Various waste formulation (combination) can be treated by GeoMelt®ICVTM and water content can be adjusted in waste
combination process. No problem for melting itself even for waste with a high water content but some issues could potentiallyoccur in handling process for feeding (plugging etc.). From this point of view, demonstrate the handling and treatment ofwaste with high water content. The adjusting process of waste composition at the actual plant can be verified by thedemonstration.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 247

(2) Overview of test system(Right)Engineering scale melt test system modified
Used for 4 melt tests FY2021.
Installed waste feeding hopper and Sintered
Metal Filter (SMF) above melter.

SMF(Below)
Test system from opposite side
The orange part of the 4-electrodes melter isthe observation window (orange because themelting test is in progress)

Feed Hopper

BlowerHEPA Filter
Feed System Controls
Valve and ElectrodeControls
Indicates theoff-gas flow
direction
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

Melter48

(3) Test Materials (waste + glass additives) Blending







The Cs was adsorbed onto the KUR-EH before mixing.
According to the PNNL glass formulation, water was added to the waste (including KUR-EH which
also is glass former) and glass additive while mixing to adjust the water content, and the test
material was used.
Recipe for Melt tests
The test material containing
Melt 9Melt 10Melt 11
Melt 12Components Mass
Mass
Mass
Mass
KUR-EH was mixed with
wt%
Wt%
Wt%
Wt%
(kg)
(kg)
(kg)
(kg)
adsorbed Cs tracer (CsCl) and KUR-EH
93.62
61.19
88.11
61.19
75.60
50.21
65.62
45.57
KUR-TSG
32.97
21.55
31.03
21.55
the Sr tracer (SrCO3) to adjust
ALPS
the final test material.
42.02
27.91
Carbonate
The test material blended was Filtercake
ALPS Iron
weighed and sampled for lab
15.84
10.52
Filtercake
analysis.
ALPS

Test Waste Blend with Sample Vials

42.42
29.46
Carbonate
Slurry
SiO2
1.61
1.05
1.51
1.05
5.04
3.35
10.92
7.59
B2 O 3
7.13
4.66
6.71
4.66
5.40
3.59
4.75
3.30
Li2CO3
12.09
7.90
11.38
7.90
2.52
1.67
8.35
5.58
Na2CO3
5.58
3.65
5.26
3.65
ZrO2
3.06
2.03
11.67
8.10
ZnO
1.08
0.72
0.27
0.19
Subtotal
153.00100.00144.00100.00150.56100.00144.00100.00
Water
27.00
151
36.00
201
29.44
16.31,236.00
201
Base frit
5.00
5.00
5.00
5.00
TOF
15.00
15.00
15.00
15.00
Total
200.00200.00200.00200.00Tracers:CsCl
83.59 g78.67 g67.50 g58.59 g
SrCO3
156.32 g
156.32 g
156.32 g
156.32 g
1 water % of total test materials feed, not including BF and TOF.
2 Water content due only to the water contained in the ALPS carbonate・iron coprecipitate Filtercake.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 249

(4) Testing of transportability and feedability of ALPS carbonate・
iron coprecipitate Filtercake
 Composition of ALPS carbonate・iron coprecipitate Filtercake (henceforthcalled ALPS Filtercake) were analyzed → The result shown in the tableright below.
 ALPS Filtercake with glass formers and glass additives were tested formixability, transportability and feedability before Melt 11.
 The elemental testing: a blending test using a spiral mixing arm (“bucket
test”). → The ALPS Filtercake blended well with the glass former, additives.

ALPS Filtercake appearance Transfer/feed testing: the blended material was fed through an engineeringscale screw auger. → no problems (no sticking or clogging).

ALPS Filtercake Anions

 Blending of Melt 11 test material: blended in a 500-L vertical ribbon mixer.
Blending was for 2 hours
 Particulate transferred to off-gas increased during melting (described later) :← It was excessively pulverized as blending time was too long.
 Blending of Melt 12 test material: Using the same mixer with less time (20minutes)

SulfateALPS Carbonate
Filtercake (%)
0.0646

ALPS Iron
Filtercake (%)
0.111

Chloride

3.11

11.8

NitrateND

ND

ALPS Filtercake Bulk Chemistry
SiO2

ALPS Carbonate
Filtercake (%)
1.09

ALPS Iron
Filtercake (%)
0.79

Al2O3

0.14

0.15

Fe2O3

0.29

55.9

CaO

15.85

0.56

MgO

17.6

1.15

Na2O

17.5

10.2

K2O

0.08

0.05

LOI 1

42.5

31.6

Total

95.05

101.04

Oxide

Bucket Test with Spiral Mixing Arm

Feeding Test

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

500-L Ribbon Mixer

1 Represents the proportion of water andcarbon dioxide present in some minerals lost
during analysis.
50

(5) Melt preparation and melt test procedure
Melt preparation
 Installation of base frit, and starter pathinside refractory container.


Attach the off-gas hood on the melter.



Install electrodes remotely and connect tothe starter path.



Supply the initial test material into therefractory container, cover the starter path.

Status inside the refractory container before
melting in Melt 12
START

END

Melt test procedure The melts start with power applied through the starter path and proceeds upward (“bottom-up melting”). Add thefeed of test material.
 TOF is added at the end after all the waste. The melt ends when all the material in the refractory container has
been melted.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 251

(6) Power ramp, feeding of test materials, temperature in melterand plenum during melting test The melt power ramp was stepwise and decreased 5 kW at the start of TOF stage (to suppress Cs emission) . Melt 11 was an exception; thepower ramp was reduced and resumed to control “hazy” CO2 emissions (Power ramp is modified responding to melt condition)
 Volume was made available in the melter as test material becomes molten glass. Test material was semi-continuously fed in into the melter inorder to keep the melter full/maximize the cold cap thickness (cold cap management) The temperature in the melter rose as melt proceed from the bottom (bottom-up). Small temperature changes depended on the chemical
properties of the test material. Titanate silicate melting temperature (Melts 9,10) was higher than ALPS slurry / Filtercake melting temperature(Melts 11, 12). The temperature and power data of Melt 9 and 12 were almost the same as those of Melts 10 and 11, respectively.
 The plenum temperature remained below 125 ℃ until the TOF begins to melt, then the plenum got hotter (around 300℃ in maximum) as themelt surface becomes exposed.
Cumulative feed mass

SMF discharge

Cumulative feed mass

SMF discharge

Run Time (hr)
実施時間（hr)

TI-109

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 252

(7) Proceeding of melt (IR camera)
Melt 9１

Melt 10１（ completion ）Melt 12Melt 11（completion）（completion）

8.75 hrs

Melt 11
Remarkable CO2
generation twice (left:
8.75 hours, right10.40 hours after thestart of melting)（ completion）

Melt12
Supply of SMF
captured particulates← Immediately before:
10.30 hours after thestart of melting,10.40 hrs

1：Melts 9 and 10 did not cause any unusual events
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

10.30 hrs

Immediately after:
11.65 hours after thestart of melting→

11.65 hrs

53

(8) Refractory temperature in melter and SMF temperature・
differential pressure The thermocouple below the refractory container (TI-108 red linein the figure below left) and side of the refractory container (Ti105 blue line in the figure below left) remained below therefractory container service temperature (1650℃).

11173 ℃

 The SMF performed well below temperature and pressure design
limits (temperature = 300℃; differential pressure = 20 inchH2O
 The SMF was pulsed and discharged during the melt into themelter before the TOF was fed for Melts 10, 11, and 12
 Slight pulsation of temperature and differential pressure wereobserved at the time of changing of discontinuous stacksampling during melting.

Design Limit = 300 °C
Design Limit = 20 inches H2O

SMF back-pulse

pulsation

TI-109
TI-110
TI-111 6” 9”
3”

TI-108

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

1: The placement levels of thethermocouples that indicate
the temperature in the graphon the above are as shown
left.
54

(9) State of produced glassThe glass was cut into 4 section and 3 samples of glass were collected from each section (12 total).
Cs results show homogenous distribution throughout the glass
Residual TOF on the surface of Melt 9 was sampled. The Cs concentration in the residual TOF was
below the background value of silica sand or refractory and may not be Cs from the melt.

Cs in residual TOF was below the background

Melt 9 (KUR-EH + KUR-TSG)

Melt 11 (KUR-EH + ALPS Filtercake)
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

Melt 10 (KUR-EH + KUR-TSG)

Melt 12 (KUR-EH + ALPS Carbonate slurry)55

(10) State of the lower surface of the melter upper hoodThe underside of hood, upper part of the melter are shown with the outlet of feeding pipe (center),
insert holes of electrodes and IR camera window.



By comparison of Melt 9 (water content 15%) and Melt 10 (water content 20%), it turned out noproblems (piping blockage etc.) has occurred with increased water content (same for Melts 11 and
12).

The entire underside of the hood and the first section of off-gas pipe was wipe sampled to quantify
total Cs on inner surfaces before first stack sample point. (described later)
Melt 10Melt 9Peep
Window for
IR Camera

SMF Back
Pulse return

PlenumexhaustElectrodes
(4)

Feed
PipingPlenum Intake

Hood underside before wipe sampling
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 256

(11) Location of Off-gas Stack Sampling Continuous isokinetic (“Continuous”
hereafter) stack samplings are at 2
positions, before and after SMF
 Discontinuous isokinetic(“Discontinuous” hereafter) stacksampling is at one
position, before
SMF.

Continuous Stack
Sampling Location

Discontinuous Stack
Sampling Location
Continuous Stack
Sampling Location

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 257

(12) Results of Stack Sampling Measurement
Melt 10 sampling (same for other melt tests)

Discontinuous Stack Sampling Runs

Particulate (g)Continuous Stack Sampling Run (2)Cs Emissions (g) Off-gas stack sampling was performed according to Method
29 designed by US EPA (Environment Protection Agency)
 Continuous stack sampling was performed through from thestart of melting until melt power shutdown. Discontinuous
stack sampling was performed from the start of melting until
one hour after the melt power shutdown, separating 6 steps
responding to the time and stage of melting.
 The measurement results were compared with the melting
test results up to the previous year.
 The amount of particulate released in Melts 9,10,12 were
almost the same as the test results up to the previous year.
 The amount of particulate released in Melt 11 was especiallyhigh in run 4 and 5. This was because the test material was
excessively pulverization at the stage of blending. Melt 12
used shorter mixing times to prevent excessive pulverized,
resulting in lower particulate emissions.
 Melt 9 and 10 had slightly higher emissions during the TOF
stage than Melts 5, 6, and 7. Since the appearance of the
supply situation of TOF changed due to the new IR camera
angle, the TOF was carefully supplied to avoid overflowing
from the refractory container. This may have resulted in athinner cold cap during the TOF processing stage andslightly higher emissions for Melts 9 and 10.
 Melt 11 had high Cs emissions during the TOF stage
primarily because of excessive pulverization, the effect ofhigh chloride concentration in the ALPS Filtercake, and thelong duration of the TOF treatment stage.
 Melt 12 had elevated Cs emissions during the TOF stage(Run 5). This was because the particulates remaining in the
TOF stage of Melt 11 were also recycled in the recycling of
the SMF collected particulates before the TOF supply in
Melt12.

Melt 5Melt 6
Melt 7
Melt 9Melt 10Melt 11
Melt 12

Run 1 Run 2 Run 3 Run 4
1.31
0.52
1.13 26.27 Run 5
0.85
0.87
0.75 50.67 25.62 Run 6
0.19
0.32 47.69 45.87 20.09
1.73
0.0003
0.002
0.45
0.67
0.59
0.03
0.72
1.10
14.4 28.65 41.18
1.7
0.00
59.7
25.5 150.43 1140.23
77.3
1.8
1.5
1.2
1.76 89.33
9.3

Run 1 Run 2 Run 3 Run 4
Melt 5
0.00
0.00
0.00
1.35 Run 5
Melt 6
0.00
0.00
0.00
0.97
0.37 Run 6
Melt 7
0.00
0.00
0.06
0.10
0.44
0.01
Melt 9
0.00
0.00
0.45
0.67
0.59
0.03
Melt 10
0.00
0.00
0.28
0.68
0.70
0.02
Melt 11
0.00
0.18
0.02
0.23
9.03
0.05
Melt 12
0.02
0.01
0.00
0.02
2.09
0.14
Orange shading is TOF stage

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 258

(13) Measurement results of Cs amount including capture andrecovery of Cs by SMF
 Measurement results of each sampling points in each melt test are shown in the table below① Amount of Cs in feed of test material,② Adhesion amount of Cs in the hood and piping (until 1st continuous stack sampling point) (wipe sample)③ Amount of Cs of continuous and discontinuous stack sampling before SMF (The value of continuous + 6th
discontinuous run)
④ Amount of Cs of continuous stack sampling before SMF⑤ Amount of Cs recycled from SMF⑥ Amount of Cs of continuous stack sampling after SMF.
 Particulate (Cs) captured by SMF was treated as follows in each melt test
Melt 9: Captured through all course of melt test. Captured particulate (Cs) was not recycled to the melting container but
was recovered to the backet to measure the amount of particulate and Cs concentration.
Melt 10: Captured particulate (Cs) until the start of TOF stage was discharged to the melting container just before the
TOF feeding. The amount and concentration discharged were estimated to be the same as Melt 9.
Melt 11: Captured particulate (Cs) until the start of TOF stage was discharged to the melting container just before the
TOF feeding. The amount and concentration discharged were not measured. Captured particulate in the TOF
stage was recovered to the backet to measure the amount of particulate and Cs concentration
Melt 12: Captured particulate (Cs) until the start of TOF stage was discharged to the melting container together with theresidual particulates in the melting test 11 just before the TOF feeding. The amount and concentration were notmeasured. Captured particulate during the TOF stage was recovered to the backet to measure the amount ofparticulate and Cs concentration.
(unit: metal mass g)① Cs infeed② Cs in hood and ③ Cs in stack sampling ④ Cs in stackpiping (before(con.+ 6th discon. Run) sampling before
SMF)
before SMF
SMF (con.)⑥ Cs in stack⑤ Cs recycled
sampling after SMF
from SMF(con.)

Melt 9

73.10

0.04

1.74

1.71

1.02

0.0003

Melt 10

79.36

0.05

1.56

1.54

Not measured

0.00001

Melt 11

60.36

0.08

7.87

7.82

5.51

0.0006

Melt 12

49.64

0.04

2.15

2.01

0.75

0.0001

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 259

(14) Capture of Cs by SMF, Calculation of Cs retention rate including
recovery and SMF
 The Cs retention rate was calculated and evaluated according to the following three scenarios.
Scenario A: Cs retention by cold cap (same as previous tests): {（① - ② - ③）/①} x 100 (%)
Scenario B: Cs retention by cold cap with addition of recycled Cs: {（① - ② - ③ + ⑤）/①} x 100 (%)
Scenario C: Cs retention by cold cap and recycle of all off-gas emissions prior to SMF outlet(scenario envisioned for the actual treatment plant): {（④ - ⑥）/④} x 100 (%)


The improvement of Cs retention by SMF is evaluated by comparison of scenario A and BAs for the actual plant design, it would be adequate to adopt the value of scenario C as Cs captured by
SMF was discharged to melter in the same melt batch1 or following batch1, in addition, Cs adhering to theinside of the SMF housing and the off-gas piping up to the SMF was washed away with water after themelting was completed, so it was reasonable to use the value of Scenario C.

The filtration efficiency as a single SMF was evaluated by the ratio of ④ and ⑥. It was demonstrated tobe better than the official (catalogue) value (HEPA rate)
Cs Retention for each scenario (%)

SMF Filtration Efficiency (%)

Melt

9

10

11

12

Melt

9

Scenario A

97.56

97.97

86.82

95.59

Cs

99.98 100.00

Scenario B

98.96 99.262

95.95

97.10

Scenario C

99.98 100.00

99.99 100.00

10

11

12

99.99 100.00

1: Melt processing per vitrified waste was called a batch.
2: Since the recycling amount used in the calculation of scenario B of Melt 10 was the same as that of Melt 9, the recycling
amount of Melt 9 was used.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 260

(15) Operation condition at the final stage for suppression of Cs
emission The thickness of cold cap at the TOF
stage was evaluated by combination of① IR picture of feed surface at the
final feed of test material before the
TOF feeding② Temperature gradient andtemperature of TI-109 at the TOF
feeding.
 Melts 9 and 10 had a thinner cold cap
thickness due to the careful feeding ofadditional test material due to themounting angle of the new IR camera.
 Improvement of feed method for Melts
11 and 12 produced a significantly
thicker cold cap.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 261

(16) Operating conditions at the end of melting to suppress Cs emission(Reflection of basic test on suppression of Cs volatilization at the end of melting) The 2021 engineering-scale melting test reflected the “basic test on suppression of Cs volatilization
at the end of melting.”
How to reflect toengineering-scalemelting tests

Result of engineeringscale melting tests

TOF thickness

Cs emissions were inversely correlated to TOF
thickness. Cs emission from wastes under
TOF(hTF0=10cm) was ~0.3% of total Cs inwastes using maximum TF (1350℃). Thinner
TOF layer on wastes increased Cs emission.

Make the TOF thickness
10 cm or more.

Cold Cap Thickness after the
TOF Feed:
Melt 9: 13 cm
Melt 10: 10 cm
Melt 11: 17 cm
Melt 12: 21 cm

TOF Feed Timing

Feeding of the TOF on waste mixture wasbetter to be done before subsidence of surface
of waste mixture.

Feed the TOF as soon as
possible after the feed of
the test material wascompleted.

After the last test material wasfed, the TOF was fed as soon aspracticable while checking withan IR camera.

Surface temperature oftest material before TOF(Ts)Practically, TS~100℃ just before subsidenceof waste mixture because moisture fromwastes(~100℃) heats top of waste mixture andkept TS ~ constant until completely dried.

Since Ts with an IR
camera could not be
The test material Ts before themeasured over time, it
first TOF feed was a range fromcould not be used as a
104℃ to 147℃.
guideline for the TOF feed.

Melt surface temperature
at the end of mixing ofmolten TOF and molten
waste mixture (Ts)Melt TS >1100℃ was necessary to complete
melting of TOF and mixing with melted wastes;smooth glass surfaces were formed after
cooling to solid glass.

For the same reason as
above, the melt Ts could
not be controlled.

The melt Ts at completion was arange from 232 ℃ to 815℃. This
was lower than Tokyo Tech’s
study because the surface of the
GeoMelt®ICV™ melts was cooledby plenum air.

Temperature of TI-109 at
TOF stage

In order to suppress the volatilization of Cs at
the end of melting, it was necessary to keep themelt TS at <1200℃, and for this purpose thethermocouple TI-109 was required to be kept at<1300℃. (Before performing Melt Test 12).

Melt 12 was performed bya method using thetemperature of TI-109
because the melt Ts could
not be measured directly.

The maximum temperature of
TI-109 at the TOF stage of Melt
12 was 1291℃, below thereflected 1300℃.

Criteria

Result of basic tests

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 262

(17) Engineering scale Melting tests: Test conditions and Results
Item

Melt 9Melt 10Melt 11

Melt 12

KUR-EHKUR-TSGKUR-EHKUR-TSGKUR-EHALPS Filtercake

KUR-EHALPS carbonate
SlurryWaste loading (wt%)[not include water][includes frit]73%(54% KUR-EH
19% TSG)73%(54% KUR-EH
19% TSG)

Water content (%)
Melt Duration (hours)
TOF supply

15.00
14.50

TOF Optimization

Waste

Power reduction at TOF

Off-gas stack sampling

16.30
15.50

20.00
13.33

immediately after the last waste feed
34→29 kW34→29 kWNone
(TOF power = 32 kW)1
15 kg

31→26 kW1380 – 1287℃

1414 – 1324℃

894 – 1278℃

590 – 1291℃

1.3

1.5

TOF Stage Duration (hours)

Recycle of Cs from SMF

Cs Retention
(%)

20.00
14.40

TOF amount (kg)TI-109 at TOF

78%
66%(44% KUR-EH(40% KUR-EH
ALPS 25% carbonate 26% ALPS carbonate)
9% iron coprecipitate)

No

Yes

3.3
Yes

1.8
Yes

2 continuous stack sampling (one measurement each) and 1 discontinuous sampling(measuring 6 runs)

Scenario A: Cs retention rate

97.56

97.97

86.82

95.59

Scenario B: Cs retention rate
after SMF discharge
Scenario C: Retention inglass and SMF

98.96

99.26

95.95

97.10

99.98

100.0099.99

100.00

99.97

99.99

99.74

100.00

Sr Retention rate

1 No power reduction during TOF because power was reduced earlier in the melt in response to gas generation.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 263

(18) Summary – Engineering-Scale Melting Test (1/3)
 Four engineering-scale melting tests were conducted.
 The performance of the SMF newly installed was demonstrated.
• It was demonstrated that the filtration efficiency and operability of back pulsing andrecycling the particulate captured to the melter during melting.
• The operation condition (temperature) of SMF was within the design specification andincrease of differential pressure during melting was very low.
 The emission of Cs and Sr was grasped quantitatively by continuous/discontinuous stacksampling and used for evaluation.
 It was applied that the findings obtained from the basic tests to the operation at the final
stage of melting.
 It was demonstrated that the treatment of waste with high water content (20%) without
problem (no piping blockage etc.)
 It was verified that the transportability and feeding of ALPS Filtercake by elemental test.
The melting treatment including transportability and feeding by engineering-scale was also
demonstrated.
 The melting treatment of ALPS carbonate slurry with higher waste loading (19.49%→29.46%) was demonstrated.
 The homogeneity of Cs distribution in glass by sampling and analysis after melting wasverified (Sufficiently small CV values (coefficient of variance) for Cs samples in Melts 9 to
12: 1.56-3.76%).
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 264

(18) Summary – Engineering-Scale Melting Test (2/3)
 Cs retention in glass by cold cap (Scenario A)
Melts 9, 10：Cs retention rates were slightly lower than previous Melts. Since theappearance of the supply situation of TOF changed due to the new IR camera
angle, the TOF was carefully supplied to avoid overflowing from the refractory
container. This may have resulted in a thinner cold cap during the TOF
processing stage and slightly lower Cs retention rates for Melts 9 and 10.
Melt 11： Cs retention rates were fairly low. This was attributed to the excessive
pulverization, the effect of high chloride concentration in the ALPS Filtercake
and extended duration of the TOF stage.
Melt 12： Cs retention rates were lower than expected. It was probable that the residualCs captured in the TOF treatment stage in Melt 11 was recycled together with
the Cs captured just before the TOF was supplied in Melt 12 .
 Cs retention in glass by recycling SMF captured particulate was improved.(Scenario B)• Cs retention in glass （86.82～97.97% to 95.95～99.26%） shown by recycling SMF
captured particulate to melter was improved.
 Cs retention in glass by cold cap and SMF was improved. (Scenario C)• Very high retention rate (99.98～100%) was obtained for Melts 9,10,11, and 12.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 265

(18) Summary – Engineering-Scale Melting Test (3/3)
 As a design evaluation of the actual treatment plant, the Cs captured in SMF
was recycled to the melter not only in the same melting batch1 but also in thesubsequent melting batch, also Cs adhering to the inside of SMF and off-gas
pipes was washed out into the melter with water after the completion ofmelting, so it was considered reasonable to use the value of Scenario C. In
addition, equipment for washing away Cs adhering to off-gas pipes, etc. after
melting will be examined at the design stage of the melting equipment for theactual plant.

Cold Cap
SMF

TOF

 Cs emissions were highest during the TOF stage in one batch1 of melt
treatment. The Cs concentration in the SMF captured particulates was several
times higher than that in feed waste and product vitrified waste. It was
important to capture this high condensed Cs particulate by SMF without failure.
Cold cap management was also important to obtain high Cs retention, but forsome type of waste it would not work well (high chloride concentration in Melt11). Even in such case, high retention of Cs was obtained by SMF.
 To avoid the re-emission of Cs recycled to melter from SMF, It was considered
to be better to recycle at the beginning of the subsequent melting batch１(before the first waste feed) rather than just before the start of TOF feed of thesame melting batch (runs in Melts 10 to 12). It would result in the particulateswith high Cs concentration captured by SMF being covered by the thickest
possible cold cap. (see the figures right) Note that this treatment was limited
to cases where the same waste is being treated. If recycling is done withdifferent wastes, it was necessary to examine the inventory evaluation methodof the produced vitrified waste.
 Long-term outages until subsequent melting batch was supported by backpulsing the SMF captured particulates and properly storing SMF particulates
in the lower holding section within SMF designed as high-dose equipment.

SMF

Base Frit

1: Melt processing per solidified glass is called one batch
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 266

(19) List of Engineering-Scale Melting Test Results by Subsidy Projects
Melting Test
1Melter Surface Area/Volume (cm2/L)
Waste TypeDry Feed Waste Loading (Includes
Frit) (%)
Glass Oxide Waste Loading (Includes

2

3

4

5

6

7

8

9

10

11

12

23.17
23.17
23.17
23.17
15.77
15.77
15.77
15.77
23.17
23.17
23.17
23.17
1F Soil
KUR-EH KUR-EH
KUR-EH KUR-EH KUR-EH
KUR-EH KUR-EH KUR-EH KUR-EH
KUR-EHKUR-EH
ALPS
ALPS
ALPS
KURKURALPSKURKURKURALPS
AREVA
AREVA
１
2
1
3
SlurrySlurryTSG
TSG
SlurryTSG
TSG
TSG
Filtercake Slurry2
75.77

77.44

64.39

77.44

75.55

76.02

64.00

71.00

73.17

72.64

78.25

65.88

Frit) (%)
Dry Test Materials Processed (kg)
Water Processed (kg)
Water Processed (% of Total Mass;

71.10

76.60

63.30

76.60

71.70

79.20

67.00

72.42

76.20

76.20

76.50

72.05

195.0810.92

182.7316.77

188.9036.10

181.2818.22

185.8520.15

169.7624.94

173.45
26.55

122.6411.36

153.0027.00

144.0036.00

150.5631.08

144.0036.00

Not Including Frit)
Frit Processed (kg)
Total Mass Processed (kg)
Energy (kWh)Average Power (kW)Melt Duration (hr)Processing Rate (kg/hr)
Processing Efficiency (kWh/kg)
Mass of Glass (kg)Mass Loss(%)
Volume Processed (L)Volume of Glass (L)Volume Reduction(%)
Sr Retention in Glass (%)
Scenario A:

5

8

16

9

10

13

13

8

15

20

17

20

15.00
221.00219.82
16.19
13.58
16.29
0.99
176.6020267.55
68.67
74
99.76

12.50
212.00232.67
13.89
16.75
12.66
1.10
155.8027283.23
63.93
77
99.99

15.00
240.00336.06
22.40
15.00
16.00
1.40
169.2029317.4666.00
79100.0012.50
212.00365.02
17.11
21.33
9.94
1.72
164.2623
282.67
67.77
76
99.99

15.00
221
303.09
18.65
16.25
13.6
1.37
172.6922254.0260.29
76100.0015.00
209.70345.40
19.93
17.33
12.10
1.65
166.4121241.2660.29
75
100.0015.00
215.00349.04
19.39
18.00
11.94
1.62
165.0023236.9761.15
74
100.0016.00*
150.00376.71
19.32
19.50
7.69
2.51
131.4012147.06
51.65
65
None

20.00
200.00290.63
20.04
14.50
13.79
1.45
148.0026
155.80
59.71
78
99.97

20.00
200.00344.34
23.91
14.40
13.89
1.72
135.1032
225.99
58.01
74
99.99

20.00
200.00275.57
17.78
15.50
12.90
1.38
136.3432
214.70
52.09
75.74
99.74

20.00
200.00314.16
23.55
13.33
15.00
1.57
129.8035201.2052.09
74.11
100.00

91.46

99.30

93.79

99.44

97.72

98.77

98.47

None

97.56

97.97

86.82

95.59

98.96
99.98

99.26
100.00

95.95
99.99

97.10
100.00Cs Retention in Glass (%)

Scenario B: Cs Retention in Glass with Recycle from SMF (%)
Scenario C: Cs Retention in Glass and SMF (%)

1: ALPS Carbonate・Iron coprecipitate slurry, 2: ALPS Carbonate slurry, 3: ALPS Carbonate・Iron coprecipitate Filtercake
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 267

7.4 Glass Formulation・Durability Testing
7.4.1 Increased waste loading of ALPS carbonate slurry (1) Technical approach
Objective: Extend the glass composition region where the glass property model is found to beaccurate to enable reliable high ALPS Ca-Mg slurry formulations1 (alone or together with other 1F
waste)

Increased maximum waste loading
1: ALPS carbonate slurry contains Mg, Ca, and Na. In order to increase the waste loading of carbonate, it is necessary toincrease Mg more than before, but since these increase and decrease in the same way, the formulation was studied as a"high ALPS Ca-Mg slurry".
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 268

(2) Glass composition settings for Melt 12 using test glass data

Database Gap
Analysis

Experimental study

Confirmation of
applicability to
Property Models

Glass
Optimization

Engineering Scale
Melt (M12) The areas where data was lacking in the current glass property database (high MgO region)

was identified.
 The glass composition was set to efficiently fill the unpopulated space of the database,molten glass was manufactured, and the characteristics were measured using samples thathave been rapidly cooled and slowly cooled.
 Five characteristic models were developed to predict properties as functions of glass
composition using the glass property measurement data such as viscosity, nepheline
crystallization, Mg-containing phase crystallization, MCC-1 response of crystal free glasses,
and crystal impact on MCC-1 response.
 By combining the new property model and the previous property model, the optimum glass
composition that can achieve high ALPS loading rate while satisfying the constraints of glass
characteristics (viscosity, durability, phase stability, melting temperature, electricalconductivity, etc.) was set.
 Using the updated glass composition-property model, the glass composition for Melt 12 wasformulated and the melt test have carried out.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 269

(3) ALPS-MgO Matrix design
Steps:

Target glass composition range (oxide mass fraction)for 1F waste glass loaded with high ALPS Ca-Mg

Oxide

min

max

Al2O3
B2O3
CaO
Fe 2O3
K2O
Li2O
MgO
Na2O
SiO2
ZrO2
Minors

0.019
0.04
0
0
0
0
0.08
0.04
0.4
0.03
0.0096

0.165
0.08
0.16
0.06
0.01
0.06
0.135
0.14
0.6
0.135
0.0178

Minors
TiO2
Cs2O
SO3
SrO
BaO
Cl
Cr2O3
P2O5
NiO
SUM

Concent-ration

0.005
0.001
0.00036
0.001
0.001
0.005
0.00010.00010.00010.0137

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

a new composition

existing glass

Oxide mass fractions in glass

1. Evaluate composition region of interest (collect existing
glasses and model generated glasses with MgO higher
than the current 6 wt% limit)
2. Set boundaries for glass components
3. Set property constraints to allow for glass melting (2 <viscosity at 1300°C < 10 Pa.s) (MCC-1 NLB< 10 g/m2 at 28d)4. Apply space-filling design to efficiently backfill existing
glasses with 10 new glasses in the composition regionof interest

Oxide mass fractions in glass
Scatter plot matrix of component concentration
distribution70

(4) Glasses composition
Glass composition in oxide mass fractions
Glass ID
VNS-Mg-01
VNS-Mg-02
VNS-Mg-03
VNS-Mg-04
VNS-Mg-05
VNS-Mg-06
VNS-Mg-07
VNS-Mg-08
VNS-Mg-09
VNS-Mg-10

Al2O30.08800.11600.03760.14720.05970.15410.04900.07990.13450.0307

B2O3
0.04310.05920.04170.06310.0761
0.06880.04030.06750.0466
0.0483CaO
0.13590.01220.15440.0646
0.10800.08480.06080.00350.00680.0423Fe2O30.01150.03010.03880.00800.05310.00090.00450.03260.00180.0212K2O
0.00090.00280.00980.00950.00150.00570.00790.00880.00370.0044Li2O
0.0196
0.03660.00580.04290.01570.00490.0101
0.0531
0.05820.0347MgO
0.13220.10400.08410.1167
0.09150.08100.1136
0.09780.12540.0856Na2O
0.07120.08840.05140.04130.04640.1316
0.1126
0.06140.11930.0729SiO2
0.45070.40730.43800.4024
0.46130.42070.52370.55240.43610.5458ZrO2 Others
0.0352 0.0117
0.1332 0.0102
0.1283 0.0100
0.0873 0.0169
0.0699 0.0166
0.0370 0.0107
0.0664 0.0110
0.0301 0.0130
0.0523 0.0152
0.0981 0.0160

 Measure the viscosity, MCC-1, and crystallinity of samples (next page) that have been
fabricated, cooled rapidly and slowly.
 An updated glass composition-property model to high MgO loading was applied using
the measured results to extend the range of glass properties.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 271

(5) Quenched glasses
VNS-Mg-01

VNS-Mg-02

VNS-Mg-03

VNS-Mg-04

VNS-Mg-05

VNS-Mg-06

VNS-Mg-07

VNS-Mg-08

VNS-Mg-09

VNS-Mg-10

Quenched glass: 9 visibly amorphous, 1 with crystals (VNS-Mg-02, contained ZrO2)

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 272

(6) Box center cooling (BCC) Glasses were cooled according to the BCC cooling1 conditions (BCC: Box Center Cooling in

the right figure). BCC cooling is:••••Center of 10 tG glass in refractory container, the reference for cooling
The worst case scenario for MCC-1 durability of cooling in a fireproof box for testingCooling for 4 days or more from melting to glass transition temperature (Tg)
Comparison with 1 day cooling of Hanford Waste Treatment Plant (WTP) Since BCC cooling has the slowest cooling rate, crystallization is likely to occur (see thetable below), and it is the worst condition for glass properties among cooling methods.
1: The melted glass samples were placed in a fireproof box and cooled by controlling the temperature at the center according to the
BCC cooling conditions. The blue line for BCC cooling in the figure below showed the furnace temperature control program
modeled on the BCC cooling data for 10 tG glass, and the red line showed the temperature profile of the glass sample when cooled
according to the blue line program.
NL(B) at 28 days for all VNS-Mg annealed and BCCed glasses
and total crystallinity in BCCed glasses
NLB(28 d)
BCC
NLB(28 d) BCC
Annealed
Total
Crystallinity
Glass
g·m–2
g·m–2
wt. %
VNS-Mg-01
7.5 ± 0.7
2600±250
72.8
VNS-Mg-02
9.7 ± 0.9
17.7 ± 1.7
22.9
VNS-Mg-03
9.1 ± 0.9
33.0 ± 3.2
59.9
VNS-Mg-04
9.4 ± 0.9117 ± 11
36.4
VNS-Mg-05
8.2 ± 0.8
19.3 ± 1.8
48.6
VNS-Mg-06
11.2 ± 1.1
17.0 ± 1.6
3.8
VNS-Mg-07
12.7 ± 1.2
13.1 ± 1.3
7.8
VNS-Mg-08
7.5 ± 0.7
7.3 ± 0.7
0.1
VNS-Mg-09
9.7 ± 0.9329 ± 31
54.0
VNS-Mg-10
10.0 ± 1.0
11.5 ± 1.1
7.1
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

10 tG ICV BCC

3 tG
HLW
CCC

6 tG LAW CCC

BCC and CCC cooling profiles73

(7) Analysis Result of SEM (EPMA)-EDSAmong the 20 samples produced under this study (10quenched, 10 BCCed), 5 were selected for SEM-EDS
analysis. Right Figure show the distribution of key
elements after crystallization. The elements Al, B, Na,
Mg, and Si were collected using WDS and Ca, Ti, Cl, Cr,
Cs, Ni, P, S, and Zr were collected by EDS.

 Zr-rich regions were observed in all the samples, which
was observed by XRD in these samples as baddeleyite(ZrO2). In some cases, Ti appeared to be associated with
the Zr-rich regions.
 Mg, Ca, and Si were commonly correlated in thesesamples which matches well with pyroxene group (augite
and diopside) and olivine group (forsterite) phases
observed by XRD.
 Al, Na, and Si were correlated in all the samples, somesamples (VNS-Mg-01, -04, and -09) match well with
nepheline that was determined by XRD.
 In other cases, Al, Na, Si, and B were correlated andrepresent the remainder glass phase, in samples VNSMg-03 and -05.
 Al, Si-rich dendrites were observed in VNS-Mg-04
sample that could be eucryptite based on XRD analysis.
However, because the Li cannot be measured by the
EPMA (neither by EDS nor WDS), its presence had to be
assumed.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

An example of analysis results: VNS-Mg-01 elemental
distribution maps measured by EPMA WDS (Al, B, Mg, Na,
and Si) and EDS (O, Ca, Zr, and Ti). Al,Na,Si-rich nepheline,
Mg,Ca,Si-rich diopside, and Zr,Ti rich baddeleyite

74

(8) Viscosity measurement data The viscosity results were plotted in Figure below as ln(η) vs. 104/T with viscosity units of Pa·s andtemperature units of K. A secondary (top) x-axis provided temperature in ℃ for easy reference.
 For several glasses, the measurements at 1150℃ and/or 1100℃ deviated from the line formed by
the higher temperature data points, likely as a result of crystallization in the melt.
 These data points, circled in red in Figure below, were not used for model fitting for the glasses.

Viscosity measurement example: Viscosity data when measuring VNS-Mg glass. Viscosity is displayed in Pa・s.
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 275

(9) Increased waste loading of ALPS Carbonate slurry New models based on the glass
property data (crystallinity, MCC-1, etc.)
obtained in the test (see page 73) was
needed to develop in order to enableaccurate predictions in the area where
can be vitrified with higher waste loaded
ALPS slurry.
 New property models were applied to
examine the formulation
 MCC-1 durability model Aluminosilicate crystallization modelon BCC Mg-containing phase crystallizationmodel 15 glasses with various blends of KUREH, ALPS carbonate and ALPS ironcoprecipitate slurry by updated glass
composition property model wasformulated, and the composition of Melt
12 was determined (right table: Melt 12).

 Constraints/assumptions
 Melt temperature = 1300°C
2
 MCC-1 NLB = 7.46 g/m at 28d (new model)
 PCT response same as US HLW limit
 VHT response same as US LAW limit
 Viscosity between 10 and 100 P
 Electrical conductivity between 10 and 70 S/m
 No Nepheline or Eucryptite (new model)
 < 45 wt% Mg-containing phase (new model)
 No immiscible phase separation (Taylor method) No separated sulfate salt
Glass
Waste loading rate
ALPS carbonate slurry
KUR-EHALPS Iron slurry

Melt 12（Original
model）（New
model）

81.7
19.5
57.0
5.2

75.1
29.5
45.6
0

8.3

12.5

⇒ 51 Relative % increase

Content in glass
MgO

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

Melt 1, 5⇒ 51 Relative % increase76

(10) Summary – Increased waste loading of ALPS carbonate slurry This study examined glass compositions containing 8 to 13.5 wt% MgO.
 Testing performed on 10 statistically designed glasses:• MCC-1 on quenched and slow-cooled glass (annealed, BCCed), crystallization observed by
XRD• SEM measurement on 5 glasses• Viscosity measurement
 Data collected during testing allowed to update glass composition-property models:• Updated MCC-1 durability model1 for annealed glass samples• Updated crystallinity model1• New MCC-1 durability model1 for BCCed glass samples• Updated viscosity model1
 Formulate glass for Melt 12 using the updated glass composition-property model. This glass
formulation increased the waste loading of the ALPS carbonate slurry by 51 relative percent (increased
from 19.5% to 29.5%).
Note that since the Mg(OH)2 content in the ALPS carbonate slurry stored in large quantities is a limiting
factor for increasing the loading rate of the carbonate slurry waste, increasing the MgO in the glass
requires increasing the waste loading of the ALPS carbonate slurry.
1: The property models (viscosity, nepheline crystallization, Mg-bearing phase crystallization, effect of crystal-free glass
MCC-1 response and effect of crystals on MCC-1 response) developed as a function of glass composition from glass
property measurement data in additional tests, which were the models for analyzing the constraints used in the glass
composition-property model for analyzing the final glass formulation.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 277

7.4.2 Impact of refractory on glass durability(1) Goals and control experiments
Simplified representation

Glass only

Refractory only Glass + Refractory

C - Tight configuration

C - Loose configuration

Effect of refractory if water
penetration between glass andrefractory is none to minimal.

Effect of refractory if water isallowed to penetrate between glassand refractory.

Goal: Evaluate the effect of refractory on
glass durability
 Two control experiments:
A – quantify element release fromglass aloneB – quantify element release fromrefractory alone Glass + refractory experiment:C-Implement in two different
configurations
Tight and loose configurations:
Detailed on the right and next slide
PEEK: Poly Ether Ether Ketone

PEEK bar

Glass
Refractory

Glass
Refractory

Schematic representation of the assemblies

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 278

(2) Tight configuration

5 sides of the glass coupon have theirsurface area (blue) exposed to water (→),
the face contacting the refractory was not
exposed (↓) to water (red)Furthermore, the part ( ) of the uppersurface of the glass that was in contact
with the PEEK bar was not exposed towater.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 279

(3) Comparison of glass leaching amount (from boron release)

NLB （g(g・・m
m-2-2）)

2

Yellow hatching indicates thedata range of this test.

Glass only1

Glass+refractory1

Comparison of glass leaching amount
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

In all cases, the releases observed when
the refractory is present show a lower
amount of glass altered (lower NLB) thanin the corresponding glass-alone
experiment.
1: See page 78
2: M5, 6 and 7 indicate Melts 5, 6 and 7.
3: Refractory-only results are not shownas they do not affect glass durability.
80(4) Summary – Refractory impact on glass durability

 Refractory was co-existing material in the vicinity of glass and could
affect the durability of glass.
 Durability of glass and refractory co-existed in the alteration vessel was
evaluated.
 The coexistence of refractory had a beneficial effect (reduced leaching ofglass at disposal) compared to glass alone.
 There was no significant difference in the effect of different
configurations of glass and refractory (tight and loose configurations) on
the durability of the glass when the refractory co-existed.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 281

7.4.3 Glass durability test
(1) PCT results(g・m-2)

All 3 glasses (M5/M6/M7１ ) released Na/B/Li (glass alteration tracers) in a similar manner,
but the amount is lower than P07982.
Cs release for M5/M6/M7 were similar to P0798, and lower than Na release.

1: M5, 6 and 7 indicate Melts 5, 6 and 7.
2: P0798 glass are Japanese HLW glasses andare the reference glasses for comparison of
the glasses evaluated in this test.

(g・m-2)(g・m-2)

NL(Na) and NL(Cs) comparison

Glass durability test (PCT) results
METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 282

(2) MCC-1 long-term durability test results Average data from 3 samples for each glass (In this project, the melting tests 6, 7, and 8 of the glass were-2）-2)
NLNa （g(g・m・mcontinued to be carried out.
 All NLNa < NLNa for P0798 at 28 day.
 Fast initial release, then slowing down and stabilizing beyond 28-90 day.
 All GeoMelt glasses show a lower release than the Japanese and US reference glasses (P0798, EA glass1,
respectively).

GeoMelt®ICV™
Glasses

Duration [days]

1: EA glass are US HLW glasses and are
the reference glasses for comparisonof the glasses evaluated in this test.

MCC-1 long-term durability test results

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 283

(Reference) Data of MCC-1 long term durability tests

The average results of MCC-1 are shown in the table below.
Updated Na MCC-1 normalized mass loss NLNa and Na leaching rate (average)

Glass
Melt 1
Melt 2Melt 3
Melt 4
Melt 5Melt 6
Melt 7
Melt 8
P0798

NLNa at 28 day

28–365 day Leach Rate(g/m2)(g/m2·d)6.8 ± 1.1
6.2 ± 0.7
5.0 ± 0.2
8.4 ± 2.0
8.5 ± 0.0
5.9 ± 1.3
5.4 ± 0.4
6.0 to 8.4
9.59(1.8 ± 2.0) × 10–2
(1.6 ± 0.5) × 10–2
(1.6 ± 0.5) × 10–2
(6.6 ± 2.2) × 10–3
(1.2 ± 0.1) × 10–2
(7.6 ± 7.5) × 10–3
(1.1 ± 0.8) × 10–2
5.1 × 10–3
9.0 × 10–2

Uncertainty = 2 standard deviations; not provided for Melt 8 as only two replicas
were made.

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 284

7.5 Investigation on the Applicability of GeoMelt®ICV™
(1) Purpose and Method Purpose
Holistic evaluation on the Applicability of GeoMelt®ICV™ technology to actual
processing plants

 Method
Based on the results of past tests and preliminary conceptual design, as well as thetest results obtained in this project, the following items will be comprehensively
evaluated from a technical point of view.
1.

Retrieval, Transport and Feeding

2.
3.
4.
5.
6.
7.
8.
9.
10.

Solidification Processing Equipment
Off-gas and Secondary Waste Treatment
Compliance with Regulations
Waste Specification and the Influence of Composition Fluctuations
Transfer Rate of Cs, etc. to the Off-gas System
Leaching Rate of Nuclides from Solidified Materials
Integrity of Heat-affected Containers at Disposal
Economic Efficiency of Containers
Technical Issues of Melting in the 10-ton Melter

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 285

(2) Result1 of Evaluation (1/4)
Items

Results of tests

Results of design study

1. Retrieval,Transport andFeeding It has been demonstrated thatmajor 1F waste including ALPS
carbonate・iron coprecipitate
Filtercake (Hereafter referred to as“ALPS Filtercake”) would be fed tomelter without problems.

2. Solidification
Process
Equipment It has been demonstrated that 10 tons scale melter andsolidification process equipment
perimeter system equipment(melter and perimeter systemhave been designed in PCD.
equipment) can melt 1F waste.
 Melt preparation steps, which wasset considering steps in actual plant,
has been demonstrated.

Evaluation

 The system of retrieval of No problem would be foreseen inwaste from Kurion and
GeoMelt®ICVTM for transport and
SARRY vessels and transport
feed of major 1F waste including/ feed systems have been
ALPS Filtercake.
designed in Pre-Conceptual  As for retrieval of waste, theDesign (PCD)
equipment designed in PCD
would be needed to be
demonstrated.
 In GeoMelt®ICVTM, no problem inoperation of solidification
process equipment inEngineering Scale Test
equipment.
 No problem would be foreseen in
10 tons scale melter.

3. Off-gas and It has been demonstrated that
 The off-gas treatment system  The effectiveness of SMF wasSecondary
Sintered Metal Filter (SMF)with SMF, scrubber and HEPA
confirmed by the melting test,
Waste
installed in off-gas treatment
has been designed and theand it was thought that there was(generated withsystem has high efficiency ofremoval efficiency has beenno problem with theplant operation)
particulate (Cs included) capture instudied in PCD.
configuration of the off-gas
Treatment
Engineering-Scale Tests (EST).
treatment system examined in Recycle of secondary waste
PCD.
 It has been demonstrated thatwater from off-gas treatment
particulate captured in SMF can besystem and waste retrieval
 Efficient treatment of secondary
recycled to Melter during melting
system and melt treatment ofwaste generated during
operation.
secondary solid waste
operation with solidification
generated with plant
process equipment would be
operation have been studied.
considered possible.
1: Based on the results of the tests conducted in this project, the PCD conducted in previous projects was reviewed and evaluated in this project.
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(2) Result of Evaluation (2/4)
Items
4. Compliancewith
Regulations

Results of tests
 No test implemented.

Results of design study

Evaluation

 Compliance with Japanese
Law and Regulations has
been considered in PCD.

 No problem would be foreseen in
regard of compliance withJapanese Law and Regulations.

5. Waste Glass formulation corresponding to  Influence of composition
 GeoMelt®ICVTM can handle highSpecification
waste specification has been set
fluctuations and melting
temperature and high-viscosity
and Influence ofand the fabricated glass
temperature has beenglasses, and is highly flexible inComposition
performance has been verified byconfirmed with PNNL glasssetting glass formulations. It is
Fluctuations
crucible tests
modeling (glass compositionalso possible to minimize theproperty model).
number of vitrified waste while
maximizing compositionalvariation by mixing waste andhigh melting temperatures.
 It is highly applicable to 1F waste
treatment where waste of various
specifications exists.
6. Transfer Rate of  Transfer Rate of Cs, etc. to the offCs, etc. to Offgas treatment system in each stepgas Treatmentof melting process have been
Systemmeasured in EST.

 The transfer rate has been
 High retention rate (almost
set based on the EST results100%) can be obtained by theand designed the off-gas
combination of cold cap
treatment system in PCD.
management and SMF.

 The transfer rate increases in the
final stage of melt, but due to thecold cap management the total
amount of Cs released is below
several percents of Cs in feed.
 It has been demonstrated that themost part of particulate captured by
SMF can be recycled to melter.

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(2) Result of Evaluation (3/4)
Items

Results of tests

Results of design study

Evaluation

7. Leaching Rate of  Leaching test (MCC-1) was implemented using glass
 If an evaluation model1 that
 It is thought to
Nuclides fromconsidersthenuclidebe possible
obtained by EST, leaching rate was confirmed.
Solidified
confinement performance canthat GeoMelt®
 It has been a lower leaching rate compared to the Japanese be applied, it is evaluated that
Materials
ICVTM glass
and US Reference glasses (P0798, EA glass, respectively).
there is a possibility that it can
may bebeclassified
aspit
disposal
categorized for The leaching rate in the condition of refractory coexistencefrom the viewpoint of the upper
pit disposal.
which is in disposal environment of GeoMelt®ICVTM glass
limit of concentration.
has been confirmed and it has been verified that no factor toaccelerate the leaching rate.
8. Integrity of Heat-  No test implemented.
 High Influence of heat of melting
affected
temperatureprocess on the structure of theContainers at
due to melting
10
tons
scale
melterhas
been
Disposalprocess would
studied in PCD
have no effecton the integrity
 Maximum temperature of steelof the steel incontainer of melter has turned
GeoMelt®ICVTM.
out to be well lower thansoftening temperature of steel.
9. Economic
 No test implemented.
 GeoMelt®ICVTM
 Economic Efficiency of
Efficiency ofcontainers have been studied in has many
Containers
elements of
the regard of container structure, economic
simplicity of function, treatment
superiority.
of high viscosity and hightemperature glass, flexibility,
robustness and efficiency ofenergy supplied.
 It has an advantage comparedto the glass pouring type melter.
1: Created by the projects so far.
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(2) Result of Evaluation (4/4)
Items

Results of tests

Results of design study

10. Technical Issues ofMelting in the 10-ton
Melter
① System Operability, ① Stable operation of melter (meltOperational
treatment) has been demonstrated by
Conditions
EST. It was demonstrated that stable
operation will be implemented byadjusting the electric power supply
according to the specification of waste.

 Waste treatment issues
were evaluated with
PCD and verified withmelting tests.

① PCD is considering applying
the operating method based  It would be evaluatedon the GeoMelt®ICVTM design,that technical issues forwhich has been successfully
10 tons scale melter
used for the past 20 years, tooperation have been®
TM
the 1F GeoMelt ICV
solved inequipment. The effect of SMF
GeoMelt®ICVTM.
is described in "3. Treatment
of off-gas and secondary
waste generated during
operation" and "6. Transfer
rate to off-gas system such as
Cs".

② Uniform Supply of
Waste② It has been demonstrated that uniform
supply of waste, glass frit anddischarged particulate from SMF could
be provided by single chute in EST.

③ Temperature
Distribution and
Product
Homogeneity③ It has been verified that temperature
distribution in the melter can be attained
in melter as expected. Sampling andmeasurement of produced glass has
proven the product homogeneity in EST.

④ Restart ofVitrification afterInterruption④ In EST, the melting was interrupted in
the middle of the melting process, and ④ Based on the method
then the melting of the solidified glass
implemented by EST, thewas started again. It was demonstrated
system and equipment forthat melting can be restarted andremote re-start of interrupted
processing can be completed.
melt has been studied in PCD

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Evaluation89

8. Summary (1/2)
Study on suppression of Cs emission in the final stage of melting: It was obtained that the data on the timing of top-off frit (TOF) supply after the completion of waste
supply in the final stage of melting, the supply amount (TOF layer thickness), and the relationshipbetween the melt surface temperature and the amount of Cs volatilization.
 Cs volatilization was suppressed to ~0.3% of Cs in the waste with a TOF layer thickness of 10 cm
using basic test equipment. As the TOF layer becomes thinner, Cs volatilization increases, and when
the TOF layer was absent, it increased significantly at a surface temperature exceeded 1130℃.
 Timing of TOF supply was appropriate to be before the end of water evaporation from the surface of thewaste mixture. The operation method of the engineering-scale melting test to supply as soon as
possible after the waste supply was appropriate.
 FEM was used to simulate the vertical temperature distribution of waste molten glass and TOF molten
glass. By setting the thermal conductivity in consideration of the presence of a bubble layer and theincrease in radiation heat transfer due to the transparency of the TOF molten glass, the temperature
measurement results obtained by the basic test could be simulated. The suppression of surface
temperature rose due to the increase in radiation heat transfer was also a mechanism for the
suppression of Cs volatilization by TOF.

Engineering-scale melting tests:
 Engineering-scale system was partly modified (installation of SMF etc.) and 4 melting tests wereconducted.
 The waste with water content increased to 20%, ALPS Filtercake and ALPS carbonate slurry withincreased waste loading (from 19.49% to 29.46%) were tested and melt treatment of these waste were
demonstrated. The transportability and feedability of ALPS Filtercake was verified by elemental test
prior to melting test.
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90Summary (2/2)
Engineering-scale melting tests (continued): The operability of SMF was demonstrated by recycling of captured particulates to the melter at thetiming just before the TOF supply.
 Cs retention rate was in the range of 86.82 to 97.97% only by cold cap management. It was improved
to the range of 95.95% to 99.26% by taking the recycle from SMF into account.
 Cs retention was expected to be more reliable by recycling particulates from SMF to the melter as thefirst feed waste of the next melt processing batch instead of just before the TOF feed. Furthermore,since the Cs adhering to the SMF housing and the piping to SMF was washed away with water after
the melting was completed, it was reasonable to set the Cs retention rate to 99.98% in the design of
the actual treatment plant.

Glass durability:
 A test was conducted to understand the influence of coexistence of glass and refractory, which werecomponents of the melter, in the disposal environment.
 By comparing the durability test results under the condition of glass and refractory coexistence and thecondition of glass only, it was verified that there was a beneficial effect (reduction of glass leachingamount) under the condition of coexistence of refractory. Elements (assumed to be Si, Al, and Ca)
released from refractory may have an effect.

Holistic evaluation on the applicability of GeoMelt®ICV™ technology to the treatment
for 1F water treatment secondary waste: Based on the results of the tests and pre-conceptual design conducted by the subsidized project, theimpacts of solidification equipment, transfer speed of Cs, etc. to the off-gas system, waste
specifications and composition fluctuations, etc. were evaluated.
 GeoMelt®ICV™ technology was comprehensively evaluated for its excellent applicability to thetreatment for 1F water treatment secondary waste. A bird's-eye view of the actual treatment plant was
shown (see next page).
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91

Bird's-eye view of Actual Processing Plant (10-ton batch by PCD)METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 2

92

Finally

These are the Results of the Holistic Evaluation of GeoMelt®ICV™ for Treatment of 1F
Water Treatment Secondary Wastes conducted as a Subsidiary project ofDecommissioning and Contaminated Water Treatment (FY2021) (Research andDevelopment for the Processing and Disposal of Solid Wastes)

METI GeoMelt Grant: Holistic Evaluation of GeoMelt® ICV™ Phase 293