| 1 | PNRX | United States Atomic Energy Commission, Pittsburgh Naval Reactors Office | added 7/1970; eliminated 4/1974; 1/1975-1/1980 | | NAKINA |
| 2 | PNRX | Pioneer Oil & Refining Co. | 7/1935-4/1947; 1/1950 (not listed) | | NAKINA |
| 3 | PNRX | Pioneer Oil & Refining Co. | Apr-38 | | NRHS |
| 4 | PNRX | United States Atomic Energy Commission, Pittsburgh Naval Reactors Office | added 7/70; eliminated 4/74; 1/75-1/80 | | NRHS |
| 5 | PNRX | *PIONEER OIL & REFINING CO. | | | PWRC |
| 6 | PNRX | *U. S. ATOMIC ENERGY COMMISSION, PIUTTSBURGH NAVAL REACTORS OFFICE | | | PWRC |
