From http://www.globalsecurity.org/wmd/world/china/mianyang.htm:
The Chinese Academy of Engineering Physics (CAEP), also known as the Southwest Institute, is the primary design laboratory for Chinese nuclear weapons, located in Mianyang (Sichuan).
From http://www.globalsecurity.org/wmd/world/china/mianyang.htm:
The Chinese Academy of Engineering Physics (CAEP), also known as the Southwest Institute, is the primary design laboratory for Chinese nuclear weapons, located in Mianyang (Sichuan).