Transcript Forschungszentrum Karlsruhe

Forschungszentrum Karlsruhe
in der Helmholtz-Gemeinschaft
Pre-test calculations of QUENCH-11
(Q-L2) using S/R5 and ASTEC
W. Hering, Ch. Homann
Forschungszentrum Karlsruhe
Programme NUKLEAR
P.O. Box 3640, D-76021 Karlsruhe, Germany
11th International QUENCH Workshop, October 25-27 2004
Table of Contents
•
•
•
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Motivation and objectives
Imbedding of Q-11 into Reflood Database
Status of Q-11 preparation
Summary and conclusions
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
in der Helmholtz-Gemeinschaft
Motivation and objectives
• Open issues in SFD core reflood
–
–
–
–
Reduction in H2 uncertainty
Perform a dry-out-reflood sequence test (Q-11)
Reflood with low capability systems (Q-11)
Assess risk of unintended core reflood (in case of LOOP)
• Pre-test work for QUENCH-11
–
–
–
–
Feasibility study (QWS-10)
Upgrade facility to meet requirements
First results of Q-11 pre-test experiments (Juri Stuckert)
Specification of step-by step approach to meet
requirements of QUENCH-11 (“Vorversuche”)
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
 Data base
–
–
–
–
–
–
–
EU-Programs
FZK Experiments
IRSN Phebus
OECD/NEA
USNRC
Plant accidents
LUTCH
 Reactor type
– PWR
– VVER
– BWR
K
sec
K
g
s*rod
ASTEC-Input
K/s
Fraction of total H2 mass
released during quench
7
Reflood medium
and RMFR
6
Reflood medium
Material relocation ->LH
5
Temperature increase
during starvation period
Global debris/pool
4
Steam starvation prior to
reflood (Duration)
Local debris/pool
3
Heat-up rate
Local debris
2
Pressure at reflood
Metallic melt relocated
1
PCT during test
Fuel rod damaged
0
PCT prior to reflood
Absorber damaged
Data source
Intact / loc. ballooning
Imbedding of
Q-11 into Reflood
Database
Core damage
state prior
to reflood
initiation
Reactor type
in der Helmholtz-Gemeinschaft
%
CODEX 3/1
V
1420 / 1430
L
0,3
W
0,9
1
CODEX 3/2
V
1773 / 1916
L
0,6
W
0,9
<5
PARAMETR 1
V
1700 / ~1700
L
?
Yes
W
7
?
PARAMETR 2
V
1700 / ~2700
L
?
No
W
5
?
QUENCH IBS05
P
1700 / 1750
L
?
---
W
2,6
30
QUENCH-01
"
1830 / 1900
L
0,7
60
W
1,8
7
QUENCH-02
"
2470 / 2500
L
"
W
1,7
90
QUENCH-03
"
2450 / 2500
L
"
W
1,4
(85)
QUENCH-04
"
2110 / 2340
L
"
S
1,7
16
F
QUENCH-05
"
2020 / 2270
L
"
S
1,7
7
G
Q-06 (ISP45)
"
I/F
QUENCH-07
"
QUENCH-08
"
QUENCH-09
"
QUENCH-10 (Q-L1)
"
B
Tiny
Partial
B4C
Partial
B4C
Tiny
2060 / 2150
L
"
W
1,5
11
2100 />2300
L
"
S
0,6
(68)
2070 />2300
L
"
S
0,6
45
2100 />2500
L
"
Yes
S
1,8
87
2180 / 2300
L
"
Air
W
1,8
10
L
0.5
?
W
QUENCH-11 (Q-L2)
"
QUENCH-12
V
PBF SFD ST
"
? / >2700
L
0.1
?
W
0,5
50
Phb SFD B9R2
"
? / 2150
L
<0.2
Yes
S
S
?
CORA-12
"
SIC
~2000 / 2300
L
1
---
W
1,4
?
CORA-13 (ISP-31)
"
SIC
~2100 / 2500
L
1
---
W
1,4
48
CORA-17
B
B4C
~2000 / 2300
L
1
Yes
W
1,4
79
CORA-12
P
SIC
? / >2400
L
2.2
---
W
130
75
TMI-2
P
SIC
? / >2800
H
0.5
?
H
50-180
~30
Paks (CTI)
V
1600 / ?
L
0.1
?
L
W: ?
?
11th International QUENCH Workshop, Karlsruhe, Germany
I
F
F
0.6
F
t.b.d.
Tiny
?
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I
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Q-L2 in the reflood map
Experimental data base: Depending on
Reflood Mass Flow Rate (RMFR) and Core Damage State (CDS)
Fuel relocated
Metallic blockages
Local debris/pool
Global debris/pool
Relocation-> LP
Absorber damaged
Fuel rod damaged
Fuel relocated
Metallic blockages
Local debris/pool
Global debris/pool
Relocation-> LP
Flow rate (g/s*rod)
Fuel rod damaged
Core damage
state prior to
reflood
initiation
1
2
3
4
5
6
7
1
2
3
4
5
6
7
T
L
?
?
?
?
Q Q
C C
Q
?
?
?
Q-L2
?
?
T
?
?
?
?
?
?
?
?
?
?
?
TMI-2: 50-180 (BPT)
L
Refllod mass flow rate -->
Loft LP-FP2: 130
very high (> 9.0)
All HP-SI + LP-SI
P
Q
high (2.0 - 9.0)
All LP-SI
medium (1.0 - 2.0)
All HP-SI
low ( 0.6... 1.0)
single HP-SI
very low (< 0.7)
other
Accident progression
Released Hydrogen fraction
Absorber damaged
Accident Termination
?
X
?
?
P
C
Q
Q
Q
?
L
11th International QUENCH Workshop, Karlsruhe, Germany
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?
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P
Q
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X
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P
C
Q
Q
Q
?
?
T
?
?
?
?
?
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?
?
T
L
?
?
?
?
Q
C
Q
?
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T
L
?
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?
Q
C
?
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C
Q
X
P
L
T
Data sources
CORA
QUENCH
CODEX
Parametr
LOFT LP-FP2
TMI-2
Steam
starved
(PARAMETR)
Q-11
(Q-L2)
Color coding
A H2< 20%
B
C
20 < H2 < 50%
H2 > 50%
Cat A & B
Cat B & C
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Step-by-step approach to QUENCH-11
 Test objectives
- Extend QUENCH facility to low mass flow rate scenarios
(ceasing pumps or AMM)
- Prepare facility for experiments with free water surface
- Investigate scenario with low steam availability
(app. 1g/s  0.04 g/rod*s)
 Stepwise approach


- Component tests q11v1
- Guidance and control test q11v2 (T < 600 K)
 qualification of input decks
- Design basis reflood test q11v3 (T < 1400 K)

 extend database also for DBA codes
 update of input decks
 QUENCH-11 (Q-L2)
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Best simulation of
reactor conditions
with Q-L2
 Reactor
 Consider real volumes
in the RPV:
Contribution of downcomer:
additional 80 to 120 %
of the free core flow area
• Pre-test calculations
– Pre-test experiments to
assess input decks
– Check independent
control of:
1. evaporation rate and
2. bundle heat-up
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Tools for pre-test calculations and
post-test analyses
 SCDAP/RELAP5 mod 3.2.irs:
specially modified for out-of-pile facilities
 basic tool
 ASTEC V1.x (contribution to SARNET):
 Check more possible test scenarios
(after qualification using S/R5)
 Parameter studies (fast running code)
 Due to manpower restrictions:
Code validation focussed on DIVA (~ICARE2)
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Pre-test Q-11v2
• Objectives:
 Steam flow control with
Auxiliary heater power
 Control bundle
heat-up
 Response time
of additional
water inflow
 Qualification of fluid
measurement
 Test low mass flow-rate
reflood
(< 0.7g/s*rod)
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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First post test
analysis
• Draft findings:
 Water ejected
due to flashing
even
 Bundle voided
z> 0.25 m
 Temperature rise
linearly until
bundle power
reduced
 Not observed in
experiment
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Post-test Q-11v2
• Draft findings:
 Boil-off rate
larger: z > 0.5 m,
smaller: z < 0.5 m
 Bundle
temperatures
underestimated
 Flashing observed
(due to initial
conditions)
 Check initial
conditions and
heat losses to
environment at
“low” temperatures
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Whole scenario
Pre-test calculation
(before Q-11v2):
–
Q-11v3 delivers
50-60 µm oxide layer
(reactor specific)
–
Q-11v3 reflood phase
simulates
Accumulator driven
core reflood
–
Max temperatures:
- Q-11v3: < 1350 K
- Q-11
~ 2600 K
Next steps:
1.
update input deck
2.
Check sequence
Q-11v3 and Q-11
11th International QUENCH Workshop, Karlsruhe, Germany
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Validation: ASTEC results for ISP-45
 Reasonable
simulation of
axial temperature
profile during
heat-up phase
 Onset of final
transient OK
(t< 7000s)
 Temperature
peak prior /
during reflood
underestimated
(like most of the
codes in ISP-45)
 ASTEC V1.2 in work
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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ASTEC:
draft
results for
Quench-11

Comparable to S/R5
calculations

Deviations during cooldown are due to lacking
reflood model in
(ASTEC V1.1)

Much faster than S/R5

Shows Temperature
evolution in the core as
well as shroud
insulation
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Summary and conclusions (1)
 Post test analysis identified unexpected deviations
in the S/R5 facility model:
 not required before because experiments
start at higher temperatures
 Q-11v2 proved successfully step-by-step
approach to prepare Q-11
 Free water level and steam mass flow rate
could be controlled, although predictions of precalculations differ from experiment
 QUENCH facility, originally not designed for a free water
level at lower end of the bundle is now able to simulate
that feature
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
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Summary and conclusions (2)
 Q-11v3 – Q11 pre-test calculations initiated
using results of Q-11v2
– Q-11 can be performed as proposed (QWS-10)
– Database will be released to LACOMERA partners
– Post-test analyses with ASTEC will be continued
with know-how from S/R5
 SFD-Research focused on:
 SARNET: Validation of ASTEC V1.x by code to code
and code to data
 Improvement and extension of the FZK reflood map
 Detailed simulation with S/R5 to supply integral
codes with reliable boundary conditions for Q-11
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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Forschungszentrum Karlsruhe
in der Helmholtz-Gemeinschaft
11th International QUENCH Workshop, Karlsruhe, Germany
FZK/IRS-AS W. Hering, Ch. Homann
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