A standardized method for choosing a mix design of low pH shotcrete is proposed for their intended use in the construction of a High Level Radioactive Waste (HLW) repository in order to be applied to the various geological environment of the location of the HLW repositories. The method uses a sequential development process with consideration given to a number of physicochemical requirements, incorporates current shotcrete technology. The method is demonstrated in its entirety through a series of experiments and tests using a low pH cement binder comprised of a mixture of Ordinary Portland Cement (OPC), fly ash (FA) and silica fume (SF), referred to here as high-volume FA SF cement (HFSC). Moreover, the method is referred from the demonstration of HFSC shotcrete in Horonobe underground research laboratory (Horonobe URL).