請問8老師 有關F-1, OPT問題

8老師, 您好,

我小兒子的大學每一年有三個學期, Fall / Winter / Spring.

He completed his freshman on campus, and now is a sophomore.
He is planning to stay on the campus and study during his sophomore summer term, take the junior fall term off to intern using OPT, and return to his college to study for winter and spring terms, then intern again in his junior summer.

After first time using OPT during his junior fall, he will only study 6 mouths instead of 9 months during the academic year.
 

My questions are:

1.      Will his F-1 visa be cancelled?
 

2.      Will he be eligible to gain OPT second time for his junior summer intern?
 

非常感謝