Quorum requirements for a referendum to be valid

Tanzania, United Republic of
Answer
No quorum requirements
Source
Constitution (2005)
http://unpan1.un.org/intradoc/groups/public/documents/un-dpadm/unpan040857.pdf
Constitutional Review Act, adopted in 2011(and amended in 2012) provides for an ad-hoc referendum.
http://polis.parliament.go.tz/PAMS/docs/8Eng-2011.pdf
THEREFERENDUM ACT, 2013
http://www.parliament.go.tz/assets/uploads/files/47716-A-BILL---THE-REFERENDUM-.pdf