Achievements and Status of Research Activities in the Containment Area

rangebeaverMechanics

Feb 22, 2014 (3 years and 6 months ago)

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Achievements and Status of Research Activities
in the Containment Area


L. Meyer, H. Wilkening, I. Kljenak, D. Magallon





The 2
nd

European Review Meeting on Severe Accident Research

ERMSAR
-
2007

Forschungszentrum Karlsruhe (FZK), Germany, 12
-
14 June 2007


CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





2

Containment issues

Early

containment failure by pressure increase due to
fast

heat
transfer by


hydrogen combustion


explosive melt
-

water

reaction (FCI)


debris


gas

heat transfer coupled with hydrogen combustion (DCH)


Issues

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





3

Organization of the CONTAINMENT group



WP12: Hydrogen Behaviour in Containment (HBC)


Hydrogen Combustion


(HC
-

WP 12
-
1)


Containment Atmosphere Mixing

(CAM
-

WP 12
-
2 )

WP13: Fast Interaction with Corium (FIC)



Fuel Coolant Interaction


(FCI
-

WP 13
-
1 )



Direct Containment Heating

(DCH
-

WP 13
-
2 )




Organisation


CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





4

WP 12: Hydrogen Behaviour in Containment (HBC)


DDT
FA
Slow Turbulent
Flame
non
-
critical
Fast
Turbulent
Flame
critical
Detonation
critical
Initial Distribution
(Dispersion)
Initial Hydrogen
Distribution with
gradients
Release
Hydrogen
Release as a
Consequence
of an
Accident
DDT
DDT
FA
FA
Slow Turbulent
Flame
non
-
critical
Slow Turbulent
Flame
non
-
critical
Fast
Turbulent
Flame
critical
Fast
Turbulent
Flame
critical
Detonation
critical
Detonation
critical
Initial Distribution
(Dispersion)
Initial Hydrogen
Distribution with
gradients
Initial Distribution
(Dispersion)
Initial Hydrogen
Distribution with
gradients
Release
Hydrogen
Release as a
Consequence
of an
Accident
Release
Hydrogen
Release as a
Consequence
of an
Accident
Containment Atmosphere
Mixing (CAM):

Non
-
homogenous atmosphere:



thermal gradients



gas injection (steam, H
2
, other)



water spray



condensation



PARs

Hydrogen Combustion (HC):

Ignition

Flame acceleration

Recombiner

Self ignition in recombiners

Organisation


CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





5

PARTNER (16)


FACILITY

CODE (
5 LP
,
4 CFD
)

IRSN (France)



TOSQAN


TONUS CFD,
ASTEC

CEA (France)


MISTRA


TONUS CFD,
TONUS LP

UNIPI (Italy)


CONAN


FLUENT
,

FUMO

FZK (Germany





GASFLOW

GRS (Germany)




COCOSYS, ASTEC
,

JSI (Slovenia)




CFX
,

ASTEC

KTH (Sweden)




CFX

LEI (Lithuania)




COCOSYS


NRG (Netherlands)




CFX

UPM (Spain)




CFX


VEIKI (Hungary)




GASFLOW

EdF (France)




AREVA (Germany)

FZJ (Germany)

UJV (Czech Republic)



MELCOR

VTT (Finland)

Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





6

Containment Atmosphere Mixing (CAM)

Main achievements:

Simulation of interaction between containment atmosphere and


Sprays


P
assive
A
utocatalytic
R
ecombiners (PAR)


Broader issue: Influence of accident mitigation systems on




containment atmosphere

-
CFD (local instantaneous description) and lumped
-
parameter
codes used

-
Simulations also contribute to the validation of ASTEC code


CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





7

Simulation of spray experiments performed in TOSQAN
facility



Facility located at IRSN Saclay



Volume:
7 m
3
, height: 4.8 m



Wall temperature controlled



Test 101: depressurization test

Containment Atmosphere Mixing (CAM)

More details in paper S3
-
4 (last paper today)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





8

Simulation of spray experiments performed in TOSQAN
facility

Illustrative results:

pressure in
containment

0
1000
2000
3000
4000
T
i
m
e

(
s
)
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
P
r
e
s
s
u
r
e

(
b
a
r
)
E
x
p
e
r
i
m
e
n
t
C
E
A

T
o
n
u
s
-
L
P
F
Z
K

G
A
S
F
L
O
W
V
E
I
K
I

G
A
S
F
L
O
W
U
J
V

M
E
L
C
O
R
J
S
I

A
S
T
E
C
I
R
S
N

A
S
T
E
C
P
I
S
A

F
U
M
O

C
a
s
e

1
P
I
S
A

F
U
M
O

C
a
s
e

2
P
I
S
A

F
U
M
O

C
a
s
e

3
J
S
I

C
F
X

C
a
s
e

1
J
S
I

C
F
X

C
a
s
e

2
I
R
S
N

T
O
N
U
S

C
F
D
Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





9

Simulation of spray experiments performed in MISTRA
facility



Facility located at CEA Saclay


Volume:
99.5 m
3
, height: 7.4 m


Wall temperature not controlled


Steam condenses on cylindrical
condensers


Tests MASP1 & 2: depressurization
tests

Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





10

Simulation of spray experiments performed in MISTRA
facility

Illustrative results:

pressure in
containment

MASP2
-
depressurization

LP and CFD calculations
and experimental data

Containment Atmosphere Mixing (CAM)

0
1000
2000
3000
4000
5000
T
i
m
e

(
s
)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
P
r
e
s
s
u
r
e

(
b
a
r
)
E
x
p
e
r
i
m
e
n
t
G
A
S
F
L
O
W

F
Z
K
C
O
C
O
S
Y
S

G
R
S
C
O
C
O
S
Y
S

L
E
I
T
O
N
U
S
-
0
D
M
E
L
C
O
R

U
J
V
A
S
T
E
C

G
R
S
A
S
T
E
C

J
S
I
A
S
T
E
C

C
P
A

I
R
S
N
.
CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





11

PAR
-
atmosphere interaction simulation


2D simulation of 2 PAR in containment (first step: square domain)


Purpose: investigation of hydrogen distribution due to PARs

Illustrative results:
H
2

molar fraction at beginning and end of simulation
(calculated by CEA)

PAR

low H
2
-
concentration

high H
2
-
concentration

Low depletion rate below PARs

* PAR Passive Autocatalytic Recombiner

Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





12

PAR
-
atmosphere interaction simulation

Results: 3 separate layers in containment atmosphere



Upper layer: high hydrogen depletion rate



Buffer layer: intermediate zone



Lower layer: high hydrogen concentration

Although simplified modelling, results illustrate possible influence of PARs
on non
-
homogeneous containment atmosphere




Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





13

Conclusions and Perspectives


Focus of investigation has shifted to influence of accident mitigation
systems on containment atmosphere.


Current benchmark exercises will be concluded within 2008, but
improvement of modeling is not finished.


Condensation and PAR
-
atmosphere interaction modeling will be validated
on new experimental data available in 2008 (CONAN and REKO
-
4).



Containment Atmosphere Mixing (CAM)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





14

Issues selected by EUSAFE PIRT addressed in WP 12
-
1 (HC)

Physical effect involved

Experimental
Facility addressing
the issue

Flame
Propagation

Flame Acceleration in non
-
uniform
hydrogen/air/steam mixtures

ENACCEF


Pressure loads

Scaling effects in hydrogen
Combustion

RUT

Hydrogen removal
/ mitigation

The use of recombiners might
limit the explosion loads but could
also cause ignition.

REKO
-
3

Hydrogen Combustion (HC)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





15



PARTNER (6)


FACILITY

CODE (
3 LP
,
4 CFD
)

IRSN (France)


ENACCEF

ASTEC, TONUS,
TONUS
-
3D

FZJ (Germany)


REKO
-
3


REKO
-
DIREKT
(recombiner models)

FZK (Germany)




COM
-
3D

JRC (EU)




REACFLOW

TUS (Bulgaria)




ASTEC

VTT (Finland)




FLUENT,
TONUS








*CFD
-
codes







*
Lumped parameter codes

Hydrogen Combustion (HC)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





16

The E
NACCEF

test facility


(
EN
ceinte d’
ACCE
lération de
F
lamme)


The upper dome part with
a total volume of 0.66 m
3


The lower driver tube
with a length of 3.2 m and
a diameter of 0.154 m

The vertical facility
ENACCEF allows to study
the effect of
hydrogen
gradients

on flame
acceleration and
deceleration. These gradients
are typical for real accident
situation.

3 experiments on flame
acceleration with defined
hydrogen concentration
gradients are available for
SARNET partners and used
in a CFD code benchmark.

Hydrogen Combustion (HC)

More details in paper S3
-
3 (next paper )

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





17



REACFLOW
simulation of
flame front (top) (temperature
distribution) and pressure
distribution (bottom) in the
dome of the ENACCEF
facility

(13 vol.% hydrogen in
air). Adaptation is based on
flame front and pressure.

ENACEF CFD Code
Benchmark

CFD codes used:



FLUENT by VTT



TONUS by IRSN and VTT



REACFLOW by JRC

More details in paper S3
-
3 (next paper )

temperature

pressure

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





18

Hydrogen Removal


From the recombiner via the experiment to the model

Box
-
type recombiner

REKO
-
3

REKO
-
DIREKT

outlet

catalyst

sheets

inlet

Hydrogen Combustion (HC)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





19

Hydrogen Removal


REKO
-
3 test facility

inlet

recombiner

unit

catalyst sheets

outlet

gas analysis

Hydrogen Combustion (HC)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





20

REKO
-
3 Experriment comparison to REKO
-
DIREKT

(REKO
-
DIREKT with a new radiation model)

Influence of steam



Catalyst temperature [K]

143 x 143 mm²

(1,5 mm sheets)

T = 383
°
C

v = 0.8 m/s

y
H2o

= 20 vol.%

H
2

+ air +steam

Hydrogen Combustion (HC)

Catalyst sheet height [mm]

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





21

Perspectives for new experimental facilities

New REKO
-
4 facility
for recombiner
testing under
natural convective
flow will be
commissioned by
FZJ in TPA/JPA4.


Self ignition will be
studied in REKO
-
3
and REKO
-
4

water droplets effect on laminar flame
propagation will be studied in a special
bomb test facility by IRSN

Hydrogen Combustion (HC)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





22



Main issue:

Lower head and/or cavity failure by steam













explosion impacting containment integrity



EURSAFE:


Selected as issue needing further research



SARP:




High priority issue for
ex
-
vessel

situations



SERENA:


Code applicability to reactor situations



SARNET:


Codes/Models development




















Understanding of basic phenomena

Fuel Coolant Interaction (FCI)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





23




PARTNER (6)


FACILITY


CODE (2 CFD)

IRSN (France)





MC3D

CEA (France)


KROTOS


MC3D

FZK (Germany)





MATTINA

IKE (Germany)





IKEMIX,

IDEMO

JSI (Slovenia)





MC3D

KTH (Sweden)


MISTEE,

DEFOR



TUS (Bulgaria)








*CFD
-
codes









Fuel Coolant Interaction (FCI)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





24


Experiments:

-

KROTOS
-
PLINIUS (CEA)

-

DEFOR, MISTEE (KTH)



Codes and Models Development and Assessment:

-

MC3D (CEA, IRSN, JSI)

-

IKEMIX
-
IDEMO (IKE)



Calculations:

-

Pre
-
calculation and interpretation of experiments (All)

-

Calculation of reactor situations (CEA, IRSN, JSI, IKE)


Main focus on material influence on energetics:

-

Understand why corium
-
type melts have low energetics

Main activities

Fuel Coolant Interaction (FCI)

Topic of paper S3
-
5 (tomorrow morning)

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





25

KROTOS
-
PLINIUS test (K
-
101)


Effect of large solidification interval on FCI energetics using a corium
containing UO
2
+ZrO
2
+fission products+iron oxide


First test performed unsuccessfully, to be repeated in 2007

K-101-~2
AND ISOBARIC CALCULATION T/K
T/K
2000.
2100.
2200.
2300.
2400.
2500.
2600.
2700.
w
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1.
LIQUID

0
2
4
6
8
10
12
14
16
18
0
0.001
0.002
0.003
0.004
0.005
Time (s)
Pressure (MPa)
EXP-35
K53-A-35
K53-B-35
K53-C-35
K53-D-35
K101-A-35
K101-B-35
K101-C-35
K101-D-35


Soldification curve of K
-
101 corium

Pre
-
calculations with MC3D
(K
-
53=Ispra test with
UO
2
-
ZrO
2

corium)

Fuel Coolant Interaction (FCI)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





26

MISTEE test series


Effect of melt properties on triggerability and
explosivity


Study of fine fragmentation (explosion phase) by

X
-
ray imaging


Observations suggest that explosivity is dictated

by the first cycle dynamics and subcooling.

Analysis is on
-
going

Induction
Furnace
Melt
Release Plug
X
-
ray Tube
External
Trigger
X
-
ray
Detector/
Intensifier
Camera
Induction
Furnace
Melt
Release Plug
X
-
ray Tube
External
Trigger
X
-
ray
Detector/
Intensifier
Camera
MISTEE

Fuel Coolant Interaction (FCI)

tin drop fragmentation

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





27

Codes and Models Development


Development of MATTINA (FZK) and ESE (JSI) stopped


Only MC3D (used by CEA, IRSN, IKE and JSI) and IKEMIX
-
IDEMO (used by

IKE) are continued to be developed in SARNET

-
The two codes differ by models and approaches

-
Powerful instrument to identify
merits/shortcomings of the various
approaches and eventually converge to a common understanding


On
-
going improvements

-
Introduction of several non
-
condensable gases and modelling of surface
tension in MC3D

-
3
-
D extension of IKEMIX
-
IDEMO


Fundamental analytical work on oxidation, explosivity and fine fragmentation

(IRSN)

Fuel Coolant Interaction (FCI)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





28

Repetition of KROTOS
-
PLINIUS test

Start of SERENA
-
2
(not before 2008)


All SARNET partners will be involved with exception of TUS


Participation of US and Japan to be confirmed

Continuation of DEFOR and MISTEE tests


KROTOS is not included in SARNET, except for EC sponsored tests
in the frame of PLINIUS

Perspectives

Fuel Coolant Interaction (FCI)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





29


Direct Containment Heating (DCH)


Determination of the
dispersion of melt

in
different reactors geometries


Determination of the
pressure increase

by DCH


(heat transfer melt
-
steam/atmosphere + melt oxidation + hydrogen combustion)


Development of DCH models for ASTEC.


Analysis of experiments with models/codes and sensitivity studies on
reactor scenarios.

Objectives and activities

CONTAINMENT S3
-
2




ERMSAR
-
2007, FZK, June 12
-
14 2007





30

PARTNER (5)


FACILITY

CODE (
4 LP,
2 CFD
)

IRSN (France)




MC3D,
RUPUICUV (ASTEC)

EDF (France)




MAAP

FZK (Germany)


DISCO
-
H/C

AFDM
(discontinued 2008)

GRS (Germany)




CONTAIN, COCOSYS

TUS (Bulgaria)




ASTEC








*CFD
-
codes







*
Lumped parameter codes


Direct Containment Heating (DCH)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





31

Experiments

DISCO facility (
FZK
)


Integral and separate effects test with iron
-
alumina melt in air
-
steam
-
hydrogen
atmosphere


Modelling of different reactor cavities


Available data on

-
EPR (ECOSTAR,
FZK
)

-
1300 MWe P’4 (LACOMERA L1,

IRSN
)

-
VVER1000 (LACOMERA L2,
TUS
)




Direct Containment Heating (DCH)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





32



Door
GA 301
GA 302





Door
GA 301
GA 302
0,0
0,2
0,4
0,6
0,8
1,0
ZION
CalCliffs
EPR
P'4
VVER
DEBRIS FRACTION
Containment
Compartments
Bottom access
Pit
Typical debris dispersal fractions in different reactor designs



Direct Containment Heating (DCH)

CONTAINMENT S3
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ERMSAR
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2007, FZK, June 12
-
14 2007





33

Benchmark


Modeling of DISCO
-
L1
-
experiment with the LP
-
codes ASTEC (IRSN),
MAAP (EdF), CONTAIN (GRS) and the CFD
-
code AFDM (FZK).


A synthesis report on LP
-
model comparison has been written by
IRSN


Need for improvements of modelling in ASTEC

(Details in paper S3
-
6, tomorrow)


A second benchmark will follow in 2007 including chemical effects.

Codes and Models Development


Direct Containment Heating (DCH)

CONTAINMENT S3
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2




ERMSAR
-
2007, FZK, June 12
-
14 2007





34

Remaining open issues

Hydrogen combustion rate

under DCH conditions:



Jet of hydrogen/steam entering reactor compartments/containment
dome, containing atmosphere of air
-
steam
-
hydrogen mixture.
This process may be scale dependent.

Solution


A test series of
separate effects

tests on hydrogen combustion
during DCH events was conducted at FZK in 2006.


Calculations with combustion codes are planned or started already.
(
COM3D
, REACFLOW, TONUS
-
CFD, connection to WP12)


Once validated, application to reactor scale is planned.
Parameters can be transferred to LP
-
codes.




Direct Containment Heating (DCH)

CONTAINMENT S3
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ERMSAR
-
2007, FZK, June 12
-
14 2007





35

Conclusion and Perspectives


DCH issue can be considered to be closed for certain reactor
geometries.


Data base for EPR, P’4 is sufficient for code/model validation


(except hydrogen combustion rate)


Data for other reactor geometries will be obtained by DISCO
experiments (KONVOI, national program)


If follow
-
up of LACOMERA is approved, two experiments can be done
sponsored by EC




Direct Containment Heating (DCH)

CONTAINMENT S3
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ERMSAR
-
2007, FZK, June 12
-
14 2007





36


WP12 & WP13 Containment issues

General Conclusions

Closed issues


very fast hydrogen explosions (fast turbulent deflagration and detonation)


hydrogen explosions with no hydrogen gradients involved, including scaling


hydrogen explosions with hydrogen gradients on small scale


in
-
vessel steam explosions


DCH for a number of reactor geometries

Open issues


scaling of hydrogen explosions when there are concentration gradients,


self ignition in recombiners,


coupling between dispersion and combustion including recombiners,


combustion of hydrogen jets in connection with DCH


the ‘material effect’ in ex
-
vessel FCI