A321 Captain reported encountering wake turbulence on arrival and landing at PHL in trail of a B787. Reporter recommended increased separation from B787 type aircraft.

Narrative

While on a vector to final for the ILS-Z 09R; PHL Approach advised us that we were following a heavy B787. After intercepting the localizer at our assigned altitude; we visually acquired the traffic and the airport. We requested and received a clearance for a visual approach and selected and designated the traffic using CAVS; which indicated that we were 6.3 miles behind; and 4 kts. slower than the traffic. We experienced two very significant jolts of wake turbulence between about 10 and 8 miles out on final; although to my surprise; they were not severe enough to cause the autopilot to disconnect. After communicating with the Pilot Monitoring; upon glide slope intercept I flew the entire visual approach at 3/4 of a dot above the glide slope. I disconnected the autopilot at about 800 ft. As planned and briefed; I initiated the landing flare at approximately 1;500 beyond the runway threshold. During the landing flare at about 10 ft. radio altitude we experienced severe wake turbulence that resulted in a roll to the right; and if not immediately corrected for; or if encountered during an auto land; would have resulted in the right wingtip or engine pylon contacting the ground. I was able to correct using near full control input; and we landed safely.Based upon my [many] years experience at this airline; with over 10;000 hours time in type; it is my absolute conclusion that 6 miles is not adequate separation between a B787 and an A321. I will never knowingly accept such a clearance again; even if it results in a delay; go-around or diversion. If these circumstances had been encountered by a less experienced or situationally aware pilot; or during a CAT II or CAT III auto land approach; it could have easily resulted in a 150 kt. cartwheeling fireball on the runway.