Separation of Transformers for Class 1E Systems in Nuclear Power Plants

Table 1

The result of load flow analysis for APR1400.

Power source	4.16 kV bus	Cat. I	Cat. II	Cat. III	Cat. IV	Cat. V
UAT	Non-Class	95.53%	97.90%	95.68%	97.41%	103.21%
	1E Bus A
	Non-Class	95.45%	97.76%	95.55%	97.30%	102.89%
	1E Bus B
	Class 1E	95.45%	97.83%	95.48%	97.28%	103.21%
	Bus A
	Class 1E	95.53%	97.90%	95.68%	97.41%	103.21%
	Bus B
	Non-Class	—	97.79%	96.40%	98.08%	103.15%
	1E Bus A
	Non-Class	—	97.70%	96.33%	98.02%	102.91%
	1E Bus B
	Class 1E	—	97.71%	96.20%	97.96%	103.15%
	Bus A
	Class 1E	—	97.79%	96.40%	98.08%	103.15%
	Bus B

the plant start-up condition (Cat. I), the electric power system receives power only through UAT.