The U.S. Department of Energy released Final Surplus Plutonium Disposition Supplemental Environmental Impact Statement (PDF file). Draft EIP was issued in 2012.

In this document DOE "describes the environmental impacts of alternatives for disposition of 13.1 metric tons (14.4 tons) of surplus plutonium for which a disposition path is not assigned, including 7.1 metric tons (7.8 tons) of plutonium from pits that were declared excess to national defense needs after publication of the 2007 NOI, and 6 metric tons (6.6 tons) of surplus non-pit plutonium. The analyses also encompass potential use of MOX fuel in reactors at the Sequoyah and Browns Ferry Nuclear Plants of TVA, and at generic reactors." The document was not intended "to reconsider DOE's previous decisions about pursuing the MOX fuel approach for 34 metric tons (37.5 tons) of weapons-grade plutonium."

In addition to a No Action Alternative, DOE considered four disposition options:

(1) Immobilization to DWPF [Defense Waste Processing Facility] Alternative - glass can-in-canister immobilization for both surplus non-pit and disassembled and converted pit plutonium and subsequent filling of the canister with high-level radioactive waste (HLW) at DWPF;

(2) MOX Fuel Alternative - fabrication of the disassembled and converted pit plutonium and much of the non-pit plutonium into MOX fuel at MFFF for use in domestic commercial nuclear power reactors to generate electricity, as well as potential disposition of the surplus non-pit plutonium that is not suitable for MFFF as contact-handled transuranic (CH-TRU) waste at the Waste Isolation Pilot Plant (WIPP);

(3) H-Canyon/HB-Line to DWPF Alternative - processing the surplus non-pit plutonium in H-Canyon/HB-Line and subsequent vitrification with HLW (in DWPF) and fabrication of the pit plutonium into MOX fuel at MFFF; and

(4) WIPP Alternative - preparing for potential disposal as CH-TRU waste at WIPP the surplus non-pit and disassembled and converted pit plutonium in H-Canyon/HB-Line and the K-Area Complex at SRS, or preparing the surplus nonpit plutonium in H-Canyon/HB-Line and the K-Area Complex at SRS and preparing the surplus disassembled and converted pit plutonium in Technical Area 55 (TA-55) facilities at Los Alamos National Laboratory (LANL).

As a result of the assessment, DOE stated that it "has no Preferred Alternative at this time for the disposition of the 13.1 metric tons (14.4 tons) of surplus plutonium."