Trace Code Validation for BWR Spray Cooling Injection and CCFL Condition Based on GÖTA Facility Experiments

Table 4

Uncertain parameters.

	Parameter	1-σ uncertainty	Type of distribution	Reference
	T/H initial parameters
1	Initial power	0.75%	Normal	[10, page 21]
2	Decay heat power table	0.75%	Normal	Own judgment
3	Water drain temperature	5K	Uniform	Own judgment
4	Water drain pressure	0.01 MPa	Uniform	Own judgment
5	Steam vent temperature	5 K	Uniform	Own judgment
6	Steam vent pressure	0.5%	Uniform	Own judgment
7	Spray system pressure	5%	Uniform	Own judgment
8	Spray system temperature	0.5 K	Uniform	Own judgment
9	Spray system mass flow	0.5%	Uniform	[10, page 21]
	Vessel-related parameters
10	Tee roughness	30%	Normal^(a)	[10, page 3.32]
11	Bundle wall roughness	30%	Normal^(a)	[11, page 3.32]
12	Bypass channel wall roughness	30%	Normal^(a)	[11, page 3.32]
13	Length of main channel	1 mm	Uniform	Own judgment
14	Length of the bypass channel	1 mm	Uniform	Own judgment
15	Length of the main channel tee	1 mm	Uniform	Own judgment
16	Length of the bypass tee	1 mm	Uniform	Own judgment
	Bundle-related parameters
17	Bundle flow area	0.5%	Uniform	Own judgment
18	Bundle hydraulic diameter	0.5%	Uniform	Own judgment
19	Bypass channel Flow Area	0.5%	Uniform	Own judgment
20	Bypass hydraulic diameter	0.5%	Uniform	Own judgment
21	Spacers friction	5%	Uniform	[8, page 35]
22	Rod emissivity	15%	Uniform	Own judgment
23	Bundle wall emissivity	15%	Uniform	Own judgment
24	CCFL slope	10%	Uniform	Own judgment
25	CCFL constant	10%	Uniform	Own judgment
	Timing
26	Spray injection trip	1 s	Uniform	Own judgment
27	Drain valve trip delay	0.5 s	Uniform	Own judgment

^aThe distribution was approximated with normal.