KIT – University of the State of Baden-Württemberg and National Large-scale Research Center of the Helmholtz Association

Institute of Apllied Materials

www.kit.edu

First results of the QUENCH-17 bundle test

on debris formation J. Stuckert, J. Moch, C. Rössger, M. Steinbrück, M. Große

presented by J. Stuckert SARNET2: WP5-COOL Review Meeting

2/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Objectives of the QUENCH-17 test

• investigation of debris bed formation for bundle with completely oxidised Zry-4 claddings filled with segmented pellet simulators

• investigation of cooling of degraded bundle during the water reflood from bottom

3/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Status of bundle preparation

Zry cladding filled with ZrO2 pellet segments and ZrO2 powder

Hf shroud

4/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Quench test with completely oxidized cladding filled with segmented pellets.

Oxidation at 1773 K during 11600 s, quench with water 80 g/h

sample inside inductive furnace during quench

sample was destroyed during handling

ZrO2 powder reacted with clad metal

oxide

pellet segment

5/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

load 10 – 100 N

check of through going oxidation

Two features of unheated test rods

+1350

+350

0

6/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

3

5

7

9

11

13

15

17

19

21

23

25

27

29

31

33

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

0 10000 20000 30000 40000 50000 60000 70000 80000

Pow

er, k

W

Tem

pera

ture

, K

Time, s

950mm: TITA/13 850mm: TITD/12

550mm: TSH9/180 450mm: TSH8/270

350mm: TSH7/180 el. power

Test scenario: el. power and readings of TC at different elevations

950 mm

850 mm 550 mm

450 mm

350 mm

1) pre-oxidation stage with 2 g/s steam and 2 g/s Ar. Complete oxidation

of Zry-4 clads between 650 and 1150 mm

2) Test termination: reflood from bottom with water flow rate 10 g/s.

7/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

0

20

40

60

80

100

120

0 10000 20000 30000 40000 50000 60000 70000 80000

H2

rele

ase,

g

Time, s

MS measurementPSI: MELCOR calculation

Integral criterion of bundle oxidation progression: hydrogen release during oxidation of Zry and Hf parts

good correspondence with pre-test calculations

8/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0

2

4

6

8

10

12

14

16

18

20

0 10000 20000 30000 40000 50000 60000 70000 80000

Con

cent

ratio

n, %

Time, s

MS: He (Zrycladdings)

MS: Kr (Hfcladdings)

FM 406: Arthrough shrouddamage

Failures of Zry claddings and Hf shroud

1st failure of Zry cladding:

5235 s

shroud failure: 25245 s

no failure of Hf claddings was registered

9/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

300

500

700

900

1100

1300

1500

1700

0

2

4

6

8

10

12

14

0 10000 20000 30000 40000 50000 60000 70000 80000

Tem

pera

ture

, K

El. r

esis

tanc

e, O

hm

Time, s

R: 650 mm

T@550mm: TSH9/180

Indication of complete oxidation at 650 mm by el. resistance measurement

resistance decrease during annealing

complete oxidation at 650 mm

Ω Zr wire

10/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

400

500

600

700

800

900

1000

1100

1200

1300

1400

77000 77200 77400 77600 77800 78000 78200 78400

Tem

pera

ture

, K

Time, s

TGS 3i TGS 3oTGS 5i TGS 5oTGS 7i TGS 7oTGS 9i TGS 9oT@GS#2: TFS 16/7 T below GS#2: TFS 15/6

Indication of debris relocation to GS#2 (reaction of thermocouples TGS installed at the top of GS#2)

debris relocation

quench initiation

11/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

-400

-200

0

200

400

600

800

1000

400

600

800

1000

1200

1400

1600

1800

78100 78200 78300 78400 78500 78600 78700 78800

Wat

er le

vel,

mm

Tem

pera

ture

, K

Time, s

TIT A/13TSH 13/270TSH 13/90TIT D/12TSH 12/180TSH 12/0TIT C/11TSH 11/180TSH 11/0TSH 10/270TSH 9/180TSH 9/0TSH 8/270TSH 8/90TFS 16/7TSH 7/180TSH 7/0TFS 15/6TSH 6/270TSH 6/90TFS 14/5TSH 5/180TSH 5/0TFS 13/4TSH 4/270TSH 4/90TFS 12/3TSH 3/180TFS 11/2TSH 2/90TFS 10/1TSH 1/0L 501

-250 mm

950 mm

350 mm

-150 mm

150 mm

750 mm

Quench phase: collapse water level and TC wetting

-50 mm

water flow through shroud damaging

12/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Reflood simulation with pellet debris inside 21-rod-bundle. Cold water flow rate 10 g/s

160 mm

292 mm

382 mm

δt=27 s: v = 5 mm/s δt=28 s: v = 3 mm/s

13/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

-400

-200

0

200

400

600

800

1000

1200

0

1

2

3

4

5

6

7

8

78000 78100 78200 78300 78400 78500 78600 78700 78800 78900

Col

laps

e w

ater

leve

l, m

m

Wat

er le

vel r

ate,

mm

/s; w

ater

eva

pora

tion

rate

, g/s

Time, s

L 501: water level rate

L 701: evaporation rate

L 501: water level

Quench phase: water level oscillations and evaporation rate

Debris?

Constant evaporation rate. Region of debris bed?

14/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

0

1

2

3

4

5

0

0.001

0.002

0.003

0.004

0.005

78000 78200 78400 78600 78800 79000

Stea

m re

leas

e ra

te, g

/s

H2

rele

ase

rate

, g/s

Time, s

H2

steam

Mass spectrometer measurements: no hydrogen production during water flow through debris

water flow through debris

interaction between

water and metal

outer side of shroud

15/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Upper parts of Zry claddings above 1200 mm

GS #4

rod #1

rod #2

rod #3

rod #4

rod #5

rod #6

rod #7

rod #8

rod #9

16/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Endoscope observation of debris relocated to top edge of GS #3 (about 1100 mm)

1. After pull-up of upper part of one Zry-4 rod (rod #2)

2. After pull-up of upper parts of all nine Zry-4 rods

view of top of GS#3 through the position of rod #2 inside the GS#4 (1350 mm)

debris of oxidised cladding and pellets on the top of GS#3

top view of GS#4 and twelve Hf claddings

1200 mm: segmented pellets inside remnant of rod #8

1100 mm: debris relocated downwards from removed nine test rods

17/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

1380 mm

1280 mm

remnant of rod #8: significantly oxidised

GS #4: completely oxidised

Withdrawn grid spacer #4 (1350 -1390 mm) and remnant of cladding relocated downwards from spacer

18/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Structure of oxidized Zry cladding at 1328 mm, T ≈ 1000 K. Stab #7.

0°

180°

upper not segmented

pellet

thick inner oxide layer

prior β-Zr

α-Zr(O)

gap

thin outer ZrO2 (starvation, spalling?)

19/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Top view of grid spacer #3 (1090 mm)

empty cladding

cladding filled with pellet segments

pellet segments between heated rods

completely oxidised GS #3

20/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Endoscope observation of debris relocated under GS #3 (about 1100 mm)

blockage at elevation 910 mm view through the empty cladding top view of empty rod #6

sintered pellets at 950 mm pellet segments at 920 mm between Zry and Hf claddings

21/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Debris collected at the top of grid spacer #3 (1090 mm)

22/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

CONCLUSIONS • The QUENCH-17 bundle test with 9 unheated internal rods (Zry-4 claddings) and 12 heated external rods (Hf claddings) was performed in two stages: 1) long pre-oxidation stage (78000 s) at Tpct=1750 K with complete oxidation of Zry-4 claddings between about 650 and 1150 mm; 2) reflood stage with slow flooding from bottom (10 g/s, or about 3 mm/s)

• Hf claddings of heated rods were intact during whole test, Hf shroud was failed at 850 mm after 25000 s.

• First failure of Zry-4 cladding was registered at 5500 s. Noticeable internal oxidation was observed at upper bundle elevations.

• Mechanical impact on the end of pre-oxidation caused debris relocation to grid spacers at 1050 mm and 350 mm.

• Steam production rate was stagnated during propagation of flooding water through the debris collected above grid spacers at 350 mm.

• Some Zry-4 claddings were not significantly damaged; the pellet segments relocated from the failed rods were captured between corresponding neighbour rods.

• Ceramics debris collected at the top of spacer at 1050 mm consist of separate pellet segments and relatively large cladding segments.

• Tomographical and metallographical investigations of region above grid spacer 350 mm should give detailed information on the degree of bundle degradation.

23/23 11.02.2013-14.02.2013

J. Stuckert – QUENCH-DEBRIS

WP5-COOL Review Meeting, Fuerteventura

Thank you for your attention

http://www.iam.kit.edu/wpt/english/471.php/ http://quench.forschung.kit.edu/