The Lee path connection algorithm, which proposed in 1961, is the most widely used method for finding wire paths on PCB and VLSI design. Recently, Jan proposed an algorithm on the raster plane with O(N^2) time. It improved Lee's algorithm from searching four connected neighbors to eight connected neighbors. We extended Jan's algorithm to the 3D shortest path algorithm with the properties of nuclear fission chain reaction on the volume. This algorithm, which also has less auxiliary linked lists and the time and memory space complexities of O(N), has been coded in C(superscript ++) language on a PC and some illustrations are presented.