by Frank N von Hippel

If the US is to end its current practice of using weapon-grade highly-enriched uranium (HEU) to fuel its nuclear submarines, then the design of the next generation of US attack submarines needs to preserve the possibility of using a larger low-enriched uranium (LEU) reactor core or of refueling the reactor, a recently released report from the JASON advisory panel indicates. While the report observes that "the transition to an all-LEU fleet could begin in the 2040s," there is opposition to LEU fuel from the US Naval Nuclear Propulsion Program, the Trump Administration and some in Congress.

The heavily redacted November 2016 analysis by the Jason group of military-technology consultants on the feasibility of developing and using low-enriched uranium (LEU) fuel in US naval propulsion reactors was released in June 2019 as a result of a Freedom of Information Act request by Steven Aftergood of the Federation of American Scientists (FAS). The US Naval Nuclear Propulsion Program (NNPP) redactions of the Jason report appear to go far beyond legitimate requirements for protecting classified design information.

Currently, US and UK naval reactors are fueled by weapon-grade highly-enriched uranium (HEU) containing 93.5% of the chain-reacting isotope, U-235. (UK reactors are based on US designs and fueled with US HEU.) In 2012, the House Armed Services Committee asked NNPP to look at the possibility of developing LEU fuel for naval reactors. LEU contains less than 20% U-235 and is considered not to be directly weapon useable. The Congressional concern was that non-weapon states interested in acquiring or developing nuclear-powered submarines (Brazil and Iran, for example) could use the US example to justify producing and stockpiling weapon-usable HEU, which would destabilize the non-proliferation regime. France and China already use LEU fuel in their submarines. Russia and India use medium-enriched uranium.

The JASON report's major conclusions are:

  1. NNPP is testing a fuel with higher uranium density. The process is expected to take 20-25 years, i.e. till the 2040s.
  2. If the fuel tests out, it will be possible to refuel with 19.75% LEU at mid-life (about 25 years) most of the ten US Ford-class aircraft carriers, the first of which was commissioned in 2017.
  3. If the next-generation attack submarines that the Navy expects to begin ordering in the mid-2030s to succeed the Virginia-class are designed to accommodate larger cores, then it will possible to equip them with LEU lifetime cores when the new fuel becomes available.
  4. It is too late to design the next-generation Columbia-class US ballistic-missile submarines to use LEU cores but, if and when they are replaced, starting around 2070, the new submarines, which have about 2.5 times the displacement of attack submarines, would be correspondingly easier to design for large LEU lifetime cores.

In its markup of the Defense Authorization Bill for Fiscal Year 2020, the House Armed Services Committee asked NNPP (see p. 494) if it could design the next attack submarine to fit a life-of-ship LEU core. It also asked about a possible alternative if the LEU core size constraint is too much of an obstacle:

"the committee directs the Administrator for Nuclear Security, in coordination with the Secretary of the Navy, to provide a report to the congressional defense committees not later than December 15, 2019, assessing the feasibility of a design of the reactor module of the Virginia-Class replacement nuclear powered attack submarine that retains the existing hull diameter but leaves sufficient space for an LEU-fueled reactor with a life of the ship core, possibly with an increased module length. If a life of the ship core is unattainable, the report should include the feasibility of a reactor design with the maximum attainable core life and a configuration that enables rapid refueling."

In its formulation of that question, the Committee raised an alternative approach to the challenge of LEU core life -- going back to mid-life refueling. Mid-life refueling was standard practice with the Los Angeles-class attack submarines, which still constitute the bulk of the US fleet of attack submarines; with the current Ohio-class ballistic missile submarines; and with all US aircraft carriers.

The JASON report accepts the nuclear navy's arguments for the economic benefits of lifetime cores for submarine reactors, which have been introduced in the Virginia-class attack submarines, 17 of which are deployed with one more launched and five under construction. The group was apparently unable to study France's rapid-refueling arrangements that have reduced the refueling times for French nuclear submarines to weeks versus the years it takes the US Navy. It also does not express concern, as at least one expert has, about possible corrosion failures of nuclear power reactor systems that would not be inspected for three to four decades. Problems with these life-of-ship systems, which are not designed for service access, can be very costly. In 2015, welding was found to be defective in a joint in the steam supply piping of three new Virginia-class submarines. Contriving a way to replace the joint took the first submarine out of service for two years. France's nuclear safety authority requires that French naval reactors be thoroughly inspected every ten years.

Five years ago, NNPP was receptive to Congressional interest in the development of LEU fuel - concluding in a 2014 study that "an advanced fuel system might enable either a higher energy naval core using HEU fuel, or allow using LEU fuel with less impact on reactor lifetime, size, and ship costs." (See also the 2016 report.)

More recently, however, NNPP has been lobbying against the LEU option with the result that, in 2018, the Trump Administration's Secretaries of the Navy and Energy wrote the Congressional Armed Services Committees:

"The replacement of highly enriched uranium with LEU would result in a reactor design that is inherently less capable, more expensive, and unlikely to support current life-of-ship submarine reactors. The LEU fuel system would affect operational availability of military assets due to necessary refueling, and would require significant new shipyard infrastructure."

As reported by Aftergood, the Trump Administration objected to funding for naval LEU fuel R&D in the Fiscal Year (FY) 2020 House Energy and Water Appropriations bill, and the Republican-led Senate Armed Services Committee, which had previously been passive on the issue, voted in its markup of the National Defense Authorization Act for a "[p]rohibition on use of funds for advanced naval nuclear fuel system based on low-enriched uranium."

For its part, the House Armed Services Committee split on the issue. It accepted the report language cited above and directed the National Nuclear Security Administration to formally create a naval LEU R&D program, but it deleted by a 33-to-24 roll-call vote $20 million included in the Chairman's mark that had been authorized for research and development on LEU fuel. The amendment to delete funds was offered by Democratic Representative Elaine Luria, a former naval-reactor engineer representing a Virginia district containing the US Navy's largest shipyard, which builds all US nuclear-powered aircraft carriers and half the modules for the Virginia-class attack submarines, and also contains Norfolk naval station, the world's largest naval base, homeport to four of seven US carrier strike groups. The full House did, however, approve $20 million in the Energy and Water Appropriations bill on June 19.

Until this year, naval LEU fuel R&D had been supported on a bipartisan basis with $5 million authorized and appropriated annually from FY16 to FY18, and $10 million in FY19 - all in bills signed into law by Presidents Obama and Trump.

U.S. National Nuclear Security Administration announced that is completed the transfer of about 700 kg of HEU from the United Kingdom. The transfer was a result of a swap agreement reached in 2016. The United States would down-blend the UK material and used it in nuclear reactor fuel. The agreement also committed the United States to providing HEU for European research reactors, including those involved in production of medical isotopes. As it was noted at the time, the agreement, while removing some HEU from the United Kingdom legitimized the continuing practice of supplying HEU to Europe. The last transfer of this kind was approved in October 2018.

by Greg Mello

On March 25, DOE released the final installment of its fiscal year (FY) 2020 funding request for its nuclear weapons, naval reactor, and nonproliferation programs, including proposed outyear spending for FYs 2021-2024. (Subsequent page numbers without associated links refer to this document.)

For some programs, the details provided raise as many questions as they answer.

1. The huge and growing "Plutonium Sustainment" budget line, for which DOE is requesting $712 million for FY2020 (p. 82), about twice last year's budget. The program covers "all things plutonium" in the nuclear weapons program, including efforts to reestablish warhead core ("pit") production capability. It is expected to double in scale again by 2023, spending $5.7 billion over the coming 5 years (p. 83).

Alarmed by the scale and growth of pit production spending absent any firm project description or management structure, last year congressional appropriators required (pp. 107-108) that the expansion of pit production be placed within a well-defined new project, with normal fiscal and management controls. That hasn't happened yet.

In this budget request the "Plutonium Sustainment" program has three subprograms (p. 119), none of which are well-defined. The first is NNSA's "Plutonium Sustainment Operations" budget line, which includes among other things everything needed to "restore" the 10 pit per year (ppy) production capacity Los Alamos National Laboratory (LANL) was recently said to already have. No dollar figure is attached.

2. A new "Savannah River Plutonium Processing Facility" (SRPPF) project, no formal description of which is included, for which $410 million is requested (p. 122) for FY2020. Presumably most of these funds would be spent at or through the Savannah River Site, although an unknown portion will be spent at LANL.

3. The "Plutonium Pit Production" (P3) Project at LANL, the scope of which "is being redefined" (p. 135). Some $21 million is requested for FY2020.

Subsequent to the budget release, National Nuclear Security Administration (NNSA) Administrator Lisa Gordon-Hagerty testified that in addition to the $410 million for SRPPF, NNSA is requesting "nearly $500 million" (at 1:18:57) for pit production at LANL. The latter figure is nowhere explained in the public budget. Neither is the apparent discrepancy between the total of these two efforts and the overall Plutonium Sustainment request.

4. The proposed $1.4 billion Material Staging Facility (MSF) (pp. 283, 288) at the Pantex nuclear weapons assembly plant, located in House Armed Services Ranking Member "Mac" Thornberry's district.

Pantex is authorized to store up to 20,000 pits (p. 7; see also footnote 3 here) as well as nuclear warheads, in its "Zone 4" magazines as well as in Zone 12, the main production area. Possible replacement of the magazines - which date from World War II and have had numerous issues related to overheating, humidity, and safety, as well as flooding and corrosion and which now face security recapitalization costs - with a consolidated storage facility has been considered for decades.

The MSF project originated in Congress - not NNSA - via Section 3142 of the FY18 National Defense Authorization Act (NDAA), which required NNSA to choose a preferred concept within 30 days of enactment (!). By now, two years later, $29 million (p. 283) has been spent trying to define the project, none of which funds were actually requested by NNSA.

In March of this year DOE, NNSA, and their contractors met at Pantex to hammer out the facility's requirements, constraints, location, necessary support facilities, and other project details. A final conceptual design is due in August 2019.

Apart from $4 million in overhead requested for the coming year (p. 283), NNSA does not propose funding this project again until FY2024, when $371 million is projected (p. 288). Given the amount, this is apparently for detailed design and initial construction. Needless to say, much could change over the coming four years.

5. The disposition of surplus plutonium, which draws on much the same set of infrastructure assets as do NNSA's other plutonium programs. First, why does NNSA seek to spend $329 million -- $220 million in FY20 and the balance in FY21 - on the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF), which was canceled in FY18? That is a lot of money to spend laying that project to rest.

6. What is the large NN construction project proposed for LANL, presented without any explanation at all except an ever-rising funding level totaling $215 million over the FY21-24 period, with no overall cost or end in sight?

7. How will NNSA allocate its limited plutonium processing and storage space, especially in LANL's crowded PF-4, given the rising programmatic importance of pit production? Will disposition suffer?

Some of these projects are evolving even as funding decisions are being made. For some, Congress doesn't know what they are, NNSA admittedly doesn't either, no fiscal or project management controls are in place, and for most of them no environmental impact analysis has been done. A key question is whether Congress will demand full explanations of these and other programs before making multibillion-dollar, multi-decade commitments.

During the plenary session held on March 14, 2019 the Conference on Disarmament failed to achieve consensus on the draft decision that would have re-established four Subsidiary Bodies to work on the issues related to the CD agenda items.

Subsidiary Bodies were first established by the Conference on Disarmament in 2018 "with a view to make progress on its agenda items." The 2018 Subsidiary Body 2, "Prevention of nuclear war, including all related matters," focused primarily on the the ban of the production of fissile materials for nuclear weapons and other nuclear explosive devices. The report on its work was adopted by the CD in September 2018.

The 2019 draft decision that failed to gain support proposed establishing the following Subsidiary Bodies:

  1. Subsidiary Body 1: Cessation of the nuclear arms race and nuclear disarmament (agenda items 1 and 2), and prevention of nuclear war, and all related matters, building on the possible ways forward identified in document CD/2138, with a particular focus on elements of legally binding instruments and additional measures, and options for negotiations.
  2. Subsidiary Body 2: Fissile material for nuclear weapons and other explosive devices )agenda items 1 and 2), building on the possible ways forward identified in document CD/2139, with a particular focus on elements of a ban of the production of such material, and options for negotiations.
  3. Subsidiary Body 3: Prevention of an arms race in outer space (agenda item 3), building on the possible ways forward identified in document CD/2140, with a particular focus on elements of legally binding instruments and additional measures on PARIS, and options for negotiations.
  4. Subsidiary Body 4: Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons (agenda item 4), building on the discussions in Subsidiary Body 4 in 2018, with a particular focus on elements of legally binding instruments and additional measures on such arrangements, and options for negotiations.

U.S. Nuclear Regulatory Commission terminated the construction license for the MOX Fuel Fabrication Facility (MFFF). The NRC letter announcing the termination was sent to the CB&I Areva MOX Services on February 8, 2019 (Enclosure 1 is the decision itself, Enclosure 2 is the justification). This step appears to officially end the project marked by delays and cost overruns.

The facility, located at the Savannah River Site, was being built to process most of the plutonium declared excess for military purposes.

High-assay low-enriched uranium (HALEU) - uranium with enrichment between 5% and 20% U-235 - is used in fuel of research reactors. A number of projects launched in recent months aim at providing the United States with the capability to produce new HALEU.

Currently, the main U.S. source of HALEU is about 10 tonnes of the material that has been produced at the Materials and Fuels Complex of the Idaho National Laboratory. The uranium was recovered from irradiated fuel of the Experimental Breeder Reactor-II (EBR-II) that operated at INL from 1964 to 1994. In addition, in June 2018 the INL received $15 million for a pilot project that will recover uranium that will be down-blended to HALEU from naval spent fuel. In January 2019, DoE completed an environmental assessment that cleared the way for launching HALEU fuel fabrication at the INL.

In January 2019, the Department of Energy announced its intent to award a $115 million three-year contract to produce HALEU to a subsidiary of Centrus, a company that runs the American Centrifuge Project. The project was shut down in 2016 and in May 2018 Centrus began the process of decommissioning the lead cascade facility at Piketon, Ohio, which included 120 centrifuges. Under the new contract, the company will deploy a cascade of 16 AC-100M centrifuges that will be able to produce HALEU with up to 19.75% enrichment by October 2020. It appears that these will be new centrifuges.

In February 2019, the enrichment company Urenco USA also announced a plan to produce HALEU in the United States. According to Urenco, some of its facilities are already licensed to produce uranium with enrichments higher than 5%. It will also explore the construction of a dedicated HALEU unit at its US facility. Urenco USA is currently operating a centrifuge plant in Eunice, New Mexico that has a capacity of 4,800 tSWU/year. Unlike the INL or Centrus material, the HALEU produced by Urenco cannot be used in defense-related applications.

Silex Systems Limited eventually decided to invest in the Global Laser Enrichment (GLE), a venture that was set up by GE-Hitachi to use the Silex technology to provide enrichment services in the United States. In 2016, GE-Hitachi announced its intent to leave GLE. Silex Systems considered purchasing the 76% share of GLE from GE-Hitachi, but decided against it in June 2018. However, on February 6, 2019 the company announced that it will be investing in GLE after all. The GE-Hitachi share will be split between Silex Systems and Canadian uranium company Cameco, which invested in the project in 2008:

Subject to finalising a mutually satisfactory binding agreement and obtaining US Government approvals, the proposed restructure of GLE would result in Silex holding a 51% interest, and Cameco increasing its interest in GLE from 24% to 49%;

Rosatom's TVEL and CNLY, a subsidiary of China's CNNC corporation, signed a contract for supply of fuel for China's CFR-600 fast neutron reactor. Under the contract, TVEL will provide fuel for the initial load of CFR-600 and then will supply fuel for reloads during the first seven years of the reactor operation. The agreement on fuel supply was reached during the June 2018 summit meeting.

Although the report does not say it explicitly, the fuel in question will be HEU fuel, manufactured by the Electrostal Plant. Russia is already supplying HEU fuel (with enrichment of 64.4%) to China's Experimental Fast Reactor, CFER. It provided fuel for the initial load of that reactor, which reached criticality in 2010, and then signed two contracts to continue supply - in October 2013 and in December 2016.

Construction of the CFR-600 reactor began in December 2017. It is not clear to what extent CFR-600 will use Russian technology. Back in 2009, Russia and China started discussions of a potential sale of two BN-800 reactors to China, but that plan did not materialize, reportedly because of concerns about technology transfer.

CFR-600 is designed to use either uranium or MOX fuel. However, it appears that the reactor will begin to operate with HEU. The reactor is based on the CFER design, so it would probably use 64.4% HEU fuel. In 2012, Russia restarted production of HEU, partly to provide HEU for fast reactors in China.

Electrostal Plant, China, Russia, CFR-600, fast reactors, HEU fuel,CFER,

All HEU removed from Nigeria

U.S. National Nuclear Security Administration announced successful removal of "the last known HEU from Nigeria." The material, "more than 1 kg" of HEU, was supplied to the NIRR-1 research reactor by China. It was returned to the country of origin. A miniature neutron source reactor (MNSR), NIRR-1 is operated by the Center for Energy Research and Training (CERT) at the Ahmadu Bello University, Zaria. It was converted to LEU fuel in October 2018.

The NIRR-1 reactor conversion and removal of HEU from Nigeria is part of the effort to convert MNSR reactors to LEU. In 2016 China converted one of its MNSR reactors, MNSR IAE in Beijing. In 2017, it helped convert the GHARR-1 reactor in Ghana. HEU was removed from Ghana in August 2017. Chinese-origin MNSR reactors that use HEU fuel are located in Pakistan and Syria. China operates an HEU MNSR reactor in Shenzhen University.

Nigeria became the 34 country plus Taiwan that had all their HEU removed. (NNSA counts 33 countries plus Taiwan, but its count does not include Iraq. UPDATE: NNSA used to exclude Iraq from its list of cleaned out countries, but recently counts it in. The current difference in numbers is due to the fact that NNSA does not count Jamaica as a cleaned out country since it has never had more than 1 kg of HEU. In any event, that material was removed in September 2015