Step 1: Calculate Side Lengths
Vertices $A(1,0,0), B(0,1,0), C(0,0,1)$.
Side $AB = \sqrt{(0-1)^{2}+(1-0)^{2}+0^{2}} = \sqrt{1+1+0} = \sqrt{2}$.
Side $BC = \sqrt{0^{2}+(0-1)^{2}+(1-0)^{2}} = \sqrt{0+1+1} = \sqrt{2}$.
Side $CA = \sqrt{(1-0)^{2}+0^{2}+(0-1)^{2}} = \sqrt{1+0+1} = \sqrt{2}$.
Step 2: Total Perimeter
Perimeter $= AB + BC + CA = \sqrt{2} + \sqrt{2} + \sqrt{2} = 3\sqrt{2}$.
Final Answer: (d)