Gagan Gupta, S. Jalaldheen, P. Chellapandi, S.C. Chetal colors March 6, 2013 FR13. Paris 19...
Transcript of Gagan Gupta, S. Jalaldheen, P. Chellapandi, S.C. Chetal colors March 6, 2013 FR13. Paris 19...
International Conference on Fast Reactors and Related Fuel Cycles: Safe
Technologies and Sustainable Scenarios
Gagan Gupta, S. Jalaldheen, P. Chellapandi, S.C. Chetal
March 6, 2013 FR13. Paris 1
REACTOR DESIGN GROUP
INDIRA GANDHI CENTRE FOR ATOMIC RESEARCH, KALPAKKAM, INDIA
Outline
• Status of FBR Program in India
• Modification from PFBR Reactor Assembly to Fast Breeder Reactor (FBR) -I &II Reactor Assembly
• Structural Analysis for FBR-I & II components
• Detailed structural analysis of other components
• Summary
March 6, 2013 FR13. Paris 2
FBR Program in India
• In India, Prototype Fast Breeder Reactor (PFBR) is under advance stage of construction at Kalpakkam. All the major components are erected. Commissioning of the Reactor will be soon.
• Further, It is planned to Build one more twin unit 500 MWe FBR – I & II.
• Towards standardization of FBR, Conceptual design of FBR-I & II is finalized based on the feedback from PFBR and detail design is under progress.
• In FBR-I & II, Innovative design features have been incorporated in the reactor assembly components, to achieve improved economy and enhanced safety.
March 6, 2013 FR13. Paris 3
Reactor Assembly - PFBR to FBR-I & II in a Nutshell
LRP
SRP
Advanced design of major components: Material inventory reduction~ 25% ,
Simplified fuel handling scheme, Reduced manufacture time, Increased safety
Box type –> Dome shape
Conical–> Single torus
GP- bolted -> welded
Primary pipes : 4 to 8
Embedded SV
4
Fast Breeder Reactor Reactor Assembly
Inner vessel with
single toroidal shell
(redan) directly
connecting grid plate
with the upper
cylindrical shell
Optimization of main
vessel thickness
Integrated liner and
safety vessel with
thermal insulation
arrangement Conical
shell for
reactor
assembly
support
Dome
shaped
roof slab
Welded grid plate
with reduced height
Eight primary pipes
Thick
plate
Rotatable
plugs
No change in
Reactor Vault Concept
1 2
3
4
5 6
7
8
March 6, 2013 FR13. Paris 5
15 14 11 13
10
07 09
05
03 01
16
08
06
12
02
13
72
5 Ø1210
0
Schematic of FBR Reactor Assembly
Focus on Reactor Assembly as it has long delivery components influencing the erection time
Roof Slab
Roof Slab (Box Type) in PFBR Roof Slab (Dome Shape) in CFBR
Deflection of Dome Shaped Roof
Slab von Mises stress in Dome
Shaped Roof Slab March 6, 2013 FR13. Paris 7
Large Rotatable Plug and Small Rotatable Plug
• In PFBR large rotatable plug (LRP) and small rotatable plug (SRP) are box type structure
• In FBR-I & II thick plate concept is conceived for SRP and LRP
Thick Plate SRP & LRP of
CFBR
Deflection contour of LRP Deflection contour of SRP
March 6, 2013 FR13. Paris 8
Grid Plate
Deflection in FBR Grid Plate Von Mises Stress distribution in FBR
Grid Plate
PFBR
BOLTED CONSTRUCTION
4 PRIMARY PIPES
Wt. 76 T
HARDFACING BETWEEN GP
and CSS
FBR
WELDED CONSTRUCTION
8 PRIMARY PIPES
Wt. 33 T
NO HARDFACING
PFBR Grid Plate
March 6, 2013 FR13. Paris 9
Inner Vessel
• The shape of inner vessel is optimised with reduced upper shell
diameter and double curvature single toroidal redan, which
results in higher buckling strength and reduced thickness and
hence reduced weight.
Overall von Mises Stress Distribution Critical bucking for Pressure and
Thermal Load
March 6, 2013 FR13. Paris 10
Main Vessel
• The Shape of Bottom dished head is optimized with
respect to buckling and plastic failure modes
Critical buckling mode
shape of Main Vessel Innovative Main vessel Bottom
dished head
March 6, 2013 FR13. Paris 11
Primary Pipe Assembly
Primary Pipe configuration for FBR
Four No. of Branch Pipe from each
Spherical Header
Large Size Seamless Pipe
Primary Pipe Configuration in PFBR
Two No. of Branch Pipe from each
Spherical header
Each Bend pipe made of three
segment joined via welding
Displacement in Radial direction Von Mises Stress in Primary pipe
March 6, 2013 FR13. Paris 12
Core Support Structure
Displacement in CSS Von Mises stress in CSS Buckling Analysis of CSS
3-D Model for CSS
March 6, 2013 FR13. Paris 13
Intermediate Heat Exchanger Tubesheet Analysis :Thickness
Optimizaion
Net Internal Reaction force distribution in IHX for Level A
Locations Analyzed in detail for Top and
Bottom Tube Sheet are Inner Rim, Outer
Rim and Weld junction
Tube Sheet
Inner Rim
Perforated Region
Outer Rim
TUBE SHEET (HALF)
TOP VIEW OF BOTTOM-
(SECTIONAL VIEW)
BOTTOM TUBE SHEET
0°, 360°
90°
180°
DETAIL-A
DETAIL-B
150
BA
3600 HOLES Ø19.3
0D.1900
OD.491
OD.579
OD.497
TUBE SHEET (HALF)
TOP VIEW OF BOTTOM-
(SECTIONAL VIEW)
BOTTOM TUBE SHEET
0°, 360°
90°
180°
DETAIL-A
DETAIL-B
150
BA
3600 HOLES Ø19.3
0D.1900
OD.491
OD.579
OD.497
Nodal stresses behaviour at the Rim junction are not uniform, Hence Elemental stresses are
calculated by linear interpolation at the Rim junctions to check the thickness of tubesheet.
15
Thickness Optimizaion – Contd…
Effect of the Groove on Outer Rim junction of the Tubesheets are analyzed and it
was found that Stress at the surface is relaxed.
Radial and Hoop stress distribution at Outer rim junction with groove on Top Tube sheet
Total Radial stress σR Vs Thickness
-80
-60
-40
-20
0
20
40
60
80
100
-10 -5 0 5 10 15
σR (MPa)
Th
ick
ne
ss
(m
m)
Total Hoop stress σH Vs Thickness
-80
-60
-40
-20
0
20
40
60
80
100
-15 -10 -5 0 5 10 15
σH (MPa)
Th
ick
ne
ss
(m
m)
Total radial stress σR Vs Thickness
-80
-60
-40
-20
0
20
40
60
80
100
-10 0 10 20 30
σR (MPa)
Th
ick
ne
ss
(m
m)
Total Hoop stress σH Vs Thickness
-80
-60
-40
-20
0
20
40
60
80
100
-5 0 5 10 15
σH (MPa)
Th
ick
ne
ss
(m
m)
Radial and Hoop stress distribution at Outer rim junction without groove on Top Tube sheet
16
Three Dimensional Tube Sheet Analyses for Steam Generator
Equivalent solid plate methodology is general procedure used to analyze
the perforated plates
It fails to give stress distribution in non uniform diameter holes, realistic
stresses at interface of perforated and solid region, pressure effect inside
the holes of perforated plate, realistic thermal stress analysis of tube
sheet, effect of temperature dependent properties in perforated region
Radial stress distribution at critical ligament
along the SCP
3-D model of tube sheet
Deflection vs. radius for all cases (Without pressure inside
holes)
Deflection vs. radius for all cases (With pressure inside
holes)
Analysis of tube sheet is carried out with 1) equivalent solid plate
method as per RCC-MR considering isotropic & anisotropic material
model and 2) Three dimensional model
Parameters used for comparing the results
1) Membrane stress intensity 2) Membrane plus bending stress
intensity 3) Deflection of perforated plate at centre
Equivalent solid plate model
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Stress Type Isotropic analysis Anisotropic analysis 3-D analysis
Pm 37.9 32.1 32.4
Pm + Pb RCC-MR, A-17 185.4 184
194.3 Modified procedure 200.7 193.2
Stress Type Isotropic analysis Anisotropic analysis 3-D analysis
Pm 59.1 54.4 47.2
Pm + Pb RCC-MR, A-17 185.42 184
212.2 Modified procedure 222.9 215.4
RCC-MR (A-17) procedure to calculate primary membrane plus bending stress
RCC-MR (A-17) uses maximum value
of radial or circumferential stress.
Contribution of axial stress value is
neglected
Pressure inside the holes of the tube
sheet is not contributing in the final
value. RCC-MR (A-17) takes
maximum value of radial or
circumferential stress which would be similar as in case of two dimensional case
zz
rr
00
00
00
000
00
00
rr
Modification in RCC-MR (A-17) rules to calculate primary membrane plus bending
stress in perforated plate
Primary membrane plus bending stress should be calculated using component wise stress which would
include effect of axial stress & pressure inside holes
Without pressure inside holes
With pressure inside holes
18
Welding Simulation : Fabrication Mismatch
Thermo-mechanical simulation of austenitic steel welding process with respect to
Main Vessel - Roof Slab shell joint was carried out.
Meshing of complete cross-section along with base metal & various idealized passes shown in different colors
March 6, 2013 FR13. Paris 19
Variation of residual stress after final cooling down along hoop direction
Distance from weld centerline (0 –
100 mm)
Ho
op
str
ess a
t in
ne
r su
rface
(-300 -
+400 M
Pa)
Axia
l str
ess a
t in
ne
r
su
rface
(-300 -
+400 M
Pa)
Distance from weld centerline (0 –
100 mm) Variation of residual stress after final cooling down along axial direction
Variation of temperature during first pass along hoop direction at t = 2 seconds
Distance from weld centerline (0 – 30
mm)
Tem
pe
ratu
re (
0 –
1600
C)
Tem
pe
ratu
re (
0 –
800
C)
Distance from weld centerline (0 – 30
mm) Variation of temperature during first pass along hoop direction at t = 12 seconds 20
Ratcheting on Enhanced Nitrogen Steel
Axial strains predicted by Enhanced Nitrogen (0.14 %)
steel (SS316EN) were much higher than the strains
predicted for SS316LN steel for the same set of
parameters.
Tensile Stress 100 Mpa
Torque +/- 1 degree
21
Sloshing Instability : Enhance Safety
Liquid free surface sloshing
under vertical excitation
Liquid filled shells under
excitation
Stability chart for dynamic stability of free
surface under vertical excitation
Numerical simulations of sodium free surface of PFBR, ensured that under
seismic excitation, response of sodium free surface is bounded
March 6, 2013 FR13. Paris 22
Sloshing Instability : Experimental Investigation
Unstable response of free surface: ωv = 1.4648
Hz, av = 0.2g
Snap shots of free surface displaying instability
Stable response of free surface: ωv = 0.5643
Hz, av = 0.02g
Snap shots of free surface displaying stability
March 6, 2013 FR13. Paris 23
Load vs. deflection (with 1 hour hold time) plot of ORNL plate at 873K
Crack appeared on both sides of ORNL Plate Axisymmetric model and stress distribution
Stress relaxation
Life RCC-MR: 2002 RCC-MR: 2007 Experimental
No: of cycles 45 51 86
Creep-fatigue damage evaluation for SS-316LN (ORNL
Plates): - RCC-MR vs. Experiments
24
Summary
• PFBR design, manufacture, construction and safety review have given rich experience.
• Comprehensive roadmap has been drawn to design and develop future FBRs with focus on economy and standardisation.
• Advance detailed Structural analysis for various structure were carried out to understand the behaviour of the components
March 6, 2013 FR13. Paris 25