PMK-2, the First Integral Thermal-Hydraulics Tests for the Safety Evaluation of VVER-440/213 Nuclear Power Plants

Table 10

RTAs and parameters characterizing RTAs in PHS-05 test for selected time windows: 0 to 350 s, 350 to 4720 s, 4720 to 5000 s, 5000 to 6997 s.

RTAs	Parameters characterizing RTAs	Type	Exp. PHS-05	ATHLET		CATHARE		RELAP5
				Calc.	Q	Calc.	Q	Calc.	Q
(1) Primary system subcooled: 0 to 350 s
Pressuriser emptying	Pressuriser empty	TSE	350 s	205	M	125	M	222	M
Primary pressure behaviour	Primary pressure at 8.8 MPa	TSE	292 s	284	M	184	M	321	M
	Primary pressure at 350 s	SVP	6.61 MPa	6.36	R	7.42	R	7.57	R
Secondary pressure behaviour	Maximum secondary pressure	SVP	5.34 MPa	5.34	R	5.41	R	5.32	E
	Secondary pressure at 350 s	SVP	5.32 MPa	5.33	R	5.33	E	5.28	E
Pump behaviour	Coast-down begins	TSE	100 s		E	100	E	102	E
	Coast-down ends	TSE	248 s		R	236.7	R	250	E
Primary mass inventory	Average break flow	IPA	0.019 kg/s		M	0.028	M	0.023	R
(2) Reactor model emptying (LE11): 350 to 4720 s
Primary pressure behaviour	Primary pressure at 1300 s	SVP	6.31 MPa	6.04	R	5.42	R	6.14	R
	Primary pressure at 4720 s	SVP	4.79 MPa	5.28	R	5.34	R	4.84	R
Secondary pressure behaviour	Secondary pressure at 4720 s	TSE	4.79 MPa	5.07	R	5.23	R	4.80	E
Loop seal behaviour	Cold leg loop seal clearing	TSE	3182 s	3203	E	2920	R	3155	E
	Hot leg loop seal clearing	TSE	1272 s	1192	R	1473	R	1204	R
Primary mass inventory	Average break flow	IPA	0.011 kg/s		R	0.016	R	0.011	E
Primary temperature behaviour	Coolant temperature at core outlet at 4720 s	SVP	534.7 K	540.5	R	541.2	R	534.9	E
(3) Core overheating, rewetting (TE15): 4720 to 5000 s
Dryout occurrence	Onset of dryout	TSE	4720 s	4260	R	4905	R	5135	R
	Minimum level in reactor model at (s)	SVP	3.05 m; 4760 s	3.26 m; 4590 s	R	1.89 m; 4908 s	R	2.59 m	R
	Time of maximum cladding temperature	STS	4768 s	4360	R	4930	R	5160	E
	Maximum cladding temperature	SVP	613 K	693	R	645.9	R	593	R
Rewetting	HPIS injection initiated	TSE	4751 s		R	4924	R	5150	R
	End of dryout	TSE	5000 s	4380	R	5000	E	5340	R
(4) Primary inventory restoration (overfeeding of pressuriser): 5000 to 6997 s
Primary pressure behaviour	Pressure at 5000 s	SVP	4.61 MPa	5.37	R	4.46	R	4.78	R
Primary temperature behaviour	Coolant temperature at core outlet at 5000 s	SVP	532.1 K	541.3	E	530	E	534.2	E
	Coolant temperature at core inlet at 5000 s	SVP	506.0 K	511.1	R	508.9	E	518.7	R
Primary mass inventory	Average break flow	IPA	0.019 kg/s		R	0.019	E	0.014	R
	Total mass through the break	IPA	94.9 kg	99.0	R	110	R	84.8	R

Q: E = excellent, R = reasonable, M = minimal, U = unqualified.