ASTEC–MAAP Comparison of a 2 Inch Cold Leg LOCA until RPV Failure

Table 4

Timing of key events in the SBLOCA predicted by ASTEC and MAAP.

	ASTEC_REF [s]	MAAP_REF [s]	ASTEC_SEN [s]	MAAP_SEN [s]
2-inch cold leg SBLOCA	0.0	0.0	0.0	0.0
Reactor trip	35	42	35	42
AFW ON	41	42	41	42
MFW OFF	55	42	55	42
SG water level at 33 narrow range	55	66	55	66
CET=649°C^1	3524	3423	3524	3423
Accumulators ON	3824	4029	3824	3824
First cladding rupture	3884	3473	3894	3473
Accumulators OFF	8774	14652	14274	8774
First significant slumping	15774	22671	20744	15561
RPV failure	16864	32361	24792	22885

There exist many different core damage surrogates for PWRs and BWRs. In this work, a core exit thermocouples temperature of 649 Celsius has been selected, among others, as it always precedes oxidation transition and it is not overly conservative. For a detailed discussion on this topic, cf. [41].