That is the rumor i heard, but i did not believe, these nukes named " broken arrow" (may be 2) left in Long Binh stock ,
Also a rumor that Vietnamese can not open all the chamber in Long Binh, so they can not find the nuke yet, US have already make 1 secret operation in 2001 to retrive the "broken arrow", but they did not success, now Long Binh and Kim Boi are 2 areas which is highly protect by VPA.
It's not used against North Vietnam,but against USSR in the cold war ,but you know, It's hard to believe, so i did not believe to, but still alot of people believe about it
I just thinks about it because some one talk about Long Binh as a hint, and remind about some very special weapon,
he mean that in early 90s, Vietnamese can open the secret chamber in Long Binh Stock and found the nuke
I don't have enough permission to post any links here yet, but if you can use Vietnamese, you can search about Long Bình stock and the " broken arrow"- mũi tên gãy