Page 117 - AERB

T1
1400 T2
T4
T5
1200 T6
T7
T8
T9
1000
Temperature (Deg C) 800 T12
T10
T11
T14
T15 (Melt)
Furnace Spout
600
400
200
0
12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00
Time
Fig. 7.19(a): Cut View of the Concrete Block after Experiment Fig. 7.19(b): Variation of Temperature as Recorded by
Different Thermocouples
7.6.7 In-vessel Retention of Corium in Calandria from corium, the experimental studies were initiated for
Vessel of PHWRs determination of high temperature tensile and creep
properties and damage behaviour of calandria material
Subsequent to commissioning of COre Melt (SS304L).
REtention Facility (COMREF), experiments were
carried out to study the in-vessel retention capability Tensile tests were carried out over the temperatures
of calandria vessel in PHWRs. It was observed that the ranging from 300 K to 1123 K for the nominal strain
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curved geometry like calandria will be able to dissipate rates of 3×10 s , 3×10 s and 3×10 s . Influence
the decay heat from corium with high margin if there are of temperature on the engineering stress-strain curves
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no obstructions on its outer surface. It was also observed is shown in Fig. 7.20 (a) for the strain rate 3×10 s .
that sub-cooling of water plays a significant role in the The systematic decrease in stress values with increase
minimum heat flux required for nucleate boiling. in temperature is noticed. As compared to 300 K and
773 K, the strong influence of strain rate on stress values
7.6.8 High Temperature Properties of Calandria is observed at 973 K in this material (Fig. 7.20 (b)).
Material The variations in tensile properties with temperature
exhibited the three distinct temperature regimes i.e.
To evaluate the in-vessel retention capability of the Regime-I (up to 473 K), Regime-II (473-873 K) and
calandria against thermal-mechanical loads generated Regime-III (>873 K).

Fig. 7.20(a): Engineering Stress-Strain Curves of SS304L at Fig.7.20(b): Effect of Strain Rate on Engineering Stress-Strain
3×10 s Strain Rate at different Temperatures Curves of SS304L at Temperatures 300, 773 and 973 K
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AERB Annual Report 2019 89