nan output

I use SE_Inception_v4.py to train the cifar10 data. The code can run normally, but the "train_loss", "train_acc", "test_loss" and "test_acc" are "nan". I try to output "batch_loss" from "_, batch_loss = sess.run([train, cost], feed_dict=train_feed_dict)", the result is "nan". Did anyone meet this problem?