Complex sentence: As an early Generation II reactor based on 1950s Soviet technology and optimized for speed of production over redundancy, the RBMK was designed and constructed with several design characteristics that proved dangerously unstable when operated outside their design specifications.
Split into simpler sentences: As an early Generation II reactor based on 1950s Soviet technology, the RBMK design was optimized for speed of production over redundancy. It was designed and constructed with several design characteristics that proved dangerously unstable when operated outside their design specifications.