CATHARE Assessment of PACTEL LOCA Experiments with Accident Management

Table 1

Test T2.1: Timing of the main events, CATHARE versus experiment

Event	Time [S] Exp.	Time [S] Pretest	Time [S] Posttest	Comment
Start of calculation	$-1500$	$-5000$	$-5000$	Stabilization
Opening break valve	$0$	$0$	$0$	7.4% cold leg break ($\varnothing$ 7.8 mm)
Reactor scram	$0$	$0$	$0$
Pumps coast-down	$0$	$0$	$0$	Coast-down linear (0–150 s)
Isolation of feedwater and steam lines	$0$	$0$	$0$	Closing time is 3 s and 10 s, respectively
Pressurizer heaters off		$18.9$	$18.9$	Level in PRZ $<2.7$ m
ACCU injection initiated to Downcomer to Upper plenum	$50$	$60$	$60$	Primary pressure $<5.5$ MPa
		$61$	$61$
END of HA injection to UP to DC	$450$	$582$	$582$	HA empty
		$586.4$	$586$
Increase of fuel cladding temperature start	$940$	$900$	$920$	Core uncovery and heat-up start
Secondary bleed	$1230$	$1166$	$1202$	Cladding temperature $>350$°C,
Primary bleed	—	—	—	Cladding temperature $>400$°C,
LPSI start	$1250$	$1205$	$1244$	Primary pressure $<0.7$ MPa
Maximal fuel cladding temperature	$1261$	$1215$	$1267$	Tclad, exp = 379°C
				Tclad, calc = 394°C posttest
				Tclad, calc = 391°C pretest
LPSI pump switched off	$2000$		$2000$
End of test	$2750$	$3600$	$2400$