An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model

Table 1

PWR uncertainty contributors.

	(a) Plant initial uid conditions
1	RCS average uid temperature
2	RCS pressure
3	Accumulator uid temperature
4	Accumulator pressure
5	Accumulator volume
6	Safety injection temperature
7	Accumulator line resistance
	(b) Plant initial core power distribution
8	Core power calorimetric uncertainty
9	Decay heat uncertainties
10	Gamma redistribution
11	Nominal hot assembly peaking factor
12	Nominal hot assembly average relative power
13	Average relative power, lower third of core
14	Average relative power, middle third of core
15	Average relative power, outer edge of core
16	Time in cycle
	(c) Thermal-hydraulic physical models
17	Break type (cold leg split or guillotine)
18	Break area (for split breaks)
19	Critical flow modeling (CD)
20	Broken loop resistance (pumps and other loop resistances)
21	Condensation modeling
22	ECC bypass entrainment and steam binding
23	Effect of nitrogen injection
	(d) Hot rod physical models
24	Local hot spot peaking factor
25	Fuel conductivity
26	Gap heat transfer coefficient
27	Fuel conductivity after burst
28	Fuel density after burst (fuel relocation)
29	Cladding reaction rate
30	Rod internal pressure
31	Burst temperature
32	Burst strain
33	Blowdown heat-up heat transfer coefficient
34	Blowdown cooling heat transfer coefficient
35	Refill heat transfer coefficient
36	Reflood heat transfer coefficient
37	Minimum film boiling temperature