Sunday, December 2, 2012

MOX Musings

How to dispose of more than 33 tons of fissile plutonium (P239), declared surplus from the nuclear weapons program?

Is it better to mix it with depleted uranium (U238), form the mixture into fuel rods (MOX), burn the fuel in civilian nuclear reactors, and then bury the exhausted, but still radioactive fuel in a deep pit for a very long time, essentially forever?

Or, is it better to combine the surplus Pu239 with waste from nuclear power plants, vitrify the highly radioactive mixture steel canisters, and then bury the canisters in a deep pit for a very long time, essentially forever?

Are either of these schemes guaranteed to permanently dispose of the surplus Pu239; i.e., such that it would be forever impossible to build a viable nuclear warhead from the nuclear wastes?

Well, maybe not! But, in this regard, details matter and much of the relevant information is classified as Secret Restricted Data; e.g., just what can be constructed successfully from waste materials of a given nuclidic composition is unknown to the general public.

Nevertheless, advocacy groups vouchsafe a variety of views on this topic. Across the spectrum of views there are, on the one hand, views associated with pessimistic  feelings about nuclear energy and, on the other, views associated with optimistic feelings about all things nuclear. Those who feel pessimistic about nuclear energy occasionally also express negative thoughts about other human attempts to control and exploit nature. Those who feel optimistic about all things nuclear also often express positive thoughts about scientific and engineering undertakings, generally.

Thus, do I reveal some of my own bias!

Now, a few quotes from websites advocating for and against MOX:

From Nuclear Information and Resource Service  (an antinuclear activist group):

Plutonium Proliferation and MOX Fuel

The Department of Energy’s (DOE) decision to mix 33 or more metric tons of plutonium from nuclear weapons with depleted uranium into a mixed-oxide fuel for use in commercial nuclear reactors is a direct reversal of decades-old U.S. policy aimed toward non-proliferation of nuclear weapons materials. A plutonium fuel program will increase the risks of nuclear terrorism and the international proliferation of plutonium.

A decision on the part of the U.S. government to engage in a large scale civilian plutonium program would encourage the continuation of the messy and dangerous reprocessing programs in Europe and Japan. A plutonium fuel program would destroy any leverage the U.S. might have to influence non-weapons states from creating their own civilian reprocessing programs.

Irradiating weapons plutonium in a reactor does not make the plutonium unusable for weapons purposes. The U.S. government proved with a nuclear test in 1962 that so-called "reactor grade" plutonium can be used in nuclear bombs. Using weapons grade plutonium in reactors does not effectively safeguard plutonium, and it undermines disarmament efforts.

A U.S. plutonium fuel program would send a clear signal to other countries: the U.S. government approves of separated plutonium fuel programs. This would undercut the government's ability to discourage reprocessing in other countries and may encourage other countries to pursue plutonium programs. Arms Control and Disarmament Agency Director John Holum explained the situation clearly in a memorandum to former Energy Secretary Hazel O'Leary: "U.S. decisions on plutonium disposition are inextricably linked with U.S. efforts to reduce stockpiles as well as limit the use of plutonium worldwide. The multi-decade institutionalization of plutonium use in US commercial reactors would set a very damaging precedent for US non-proliferation policy."

The alternative, to encase the plutonium in ceramics or glass (immobilization), will not affect the government's non-proliferation goals, nor encourage civilian reprocessing in the U.S. or elsewhere. Immobilizing plutonium will send the proper signal that plutonium is a dangerous waste and needs to be treated as such.

From the National Nuclear Security Administration:

NNSA Completes Milestones for Initial Steps in Plutonium Disposition
Nov 16, 2012

WASHINGTON, D.C. – The National Nuclear Security Administration (NNSA) has announced that it recently completed two milestones towards production of early plutonium oxide feedstock for its Mixed Oxide (MOX) Fuel Fabrication Facility. In its second year in production, NNSA exceeded the FY 2012 goal of 200 kilograms of plutonium oxide production by disassembling nuclear weapons pits and converting them into plutonium oxide at Los Alamos National Laboratory (LANL). NNSA also initiated operations at H-Canyon and HB-Line at the Savannah River Site (SRS) to begin plutonium oxide production. The oxide production at both LANL and SRS provides the initial feedstock for the MOX facility and demonstrates the first steps towards permanent plutonium disposition.

“The progress achieved at LANL and SRS in support of plutonium disposition demonstrates the benefits of utilizing existing facilities in support of NNSA’s efforts to eliminate surplus weapons plutonium,” said NNSA Administrator Thomas D’Agostino.

“Feedstock for the MOX facility represents a critical component of the U.S. plutonium disposition strategy and will enable the U.S. to meet international nonproliferation commitments while advancing President Obama’s goal of permanently reducing the number of nuclear weapons across the globe.”

The disassembly, conversion and certification, which were completed at LANL, are significant accomplishments in an ongoing effort to safely dispose of surplus weapon-grade plutonium. NNSA used the Advanced Recovery and Integrated Extraction System (ARIES) at LANL to prepare, package and certify the plutonium oxide product. Following a rigorous product certification process, Shaw AREVA MOX Services, the prime contractor for the design, construction and start-up of the MOX facility, has officially accepted a total of 442 kilograms of plutonium oxide from LANL for the MOX facility.

Savannah River Nuclear Solutions (SRNS) initiated repackaging and dissolution of the non-pit plutonium material in H-Canyon this month, marking a significant milestone for H-Canyon's efforts to support the mission to produce early feed for the MOX facility. The H-Canyon Complex will eventually provide approximately 3.7 metric tons (MT) of plutonium oxide feedstock for the MOX Fuel Fabrication Facility from the excess defense plutonium currently stored at SRS.

Under an agreement between NNSA and the Department of Energy’s Office of Environmental Management (EM), the SRS H-Canyon and HB-Line, which are owned by EM and operated by the SRS management contractor SRNS, will process plutonium to meet the specifications for use in the MOX facility. Use of the SRS’s HB-Line and H-Canyon, the only operating production-scale, shielded chemical separation facilities in the U.S., takes advantage of the extensive plutonium experience among SRNS’s H-Canyon and HB-Line staff and allows for the conversion of this plutonium into feed material that will be readily available for the MOX facility’s first years of operation. The successful startup of the dissolution process is a key milestone in preparing the materials for conversion to MOX fuel.

Through the Plutonium Management and Disposition Agreement, the U.S. and Russia have agreed to each dispose of at least 34 MT of surplus weapon-grade plutonium, enough total material for 17,000 nuclear weapons. Once at the MOX facility, the plutonium oxide from LANL along with the oxide already at SRS from H-Canyon will be blended with depleted uranium, fabricated into MOX fuel and irradiated in domestic nuclear power reactors. After the MOX fuel is irradiated in civilian reactors, it is no longer suitable for use in nuclear weapons. [A question still remains as to whether or not a crude nuclear device could be fashioned successfully from MOX fuel that had been irradiated in civilian reactors.]

Also of interest is a related topic, presented by a well-known nuclear policy expert:

Op-Ed Contributor  / New York Times
Japan’s Nuclear Mistake
November 28, 2012  

THIS year has seen a lot of concern about the confrontation between China and Japan over a group of islets in the East China Sea.

Less attention, though, is being paid to what may be a more destabilizing development: next year Japan plans to bring its long-delayed Rokkasho reprocessing plant online, which could extract as much as eight tons of weapons-usable plutonium from spent reactor fuel a year, enough for nearly 1,000 warheads. That would add to Japan’s existing stockpile of 44 tons, 9 of which are stored in domestic facilities.

Japan has repeatedly vowed never to develop nuclear weapons, and there’s no reason to doubt that now. But there’s more to worry about: reprocessing not only creates a tempting target for terrorists, it also sets a precedent for countries around the world to follow suit — and pushes the world toward rampant nuclear proliferation.

Originally, Japan, like other countries, considered the reprocessing of spent nuclear fuel necessary to obtain start-up plutonium for a new generation of plutonium “breeder” reactors that would use uranium more efficiently. But uranium remains cheap and abundant, and the planned reactors, so-called molten-sodium-cooled breeders, proved to be costly and unreliable.

Japan’s own Monju prototype breeder reactor operated for only four months in 1995 before a sodium fire shut it down. Its operators are still struggling to restart it.

Japan then shifted to a strategy of recycling separated plutonium back into the fuel of its existing reactors. That effort was delayed by technical problems and public opposition and, in the wake of last year’s Fukushima accident, appears completely unviable. Still, Japan continues to plan to reprocess its nuclear fuel.

And it does so despite international pressure. At a nuclear-security event in Seoul, South Korea, last March, President Obama said, “We simply can’t go on accumulating huge amounts of the very material, like separated plutonium, that we are trying to keep away from terrorists.”

Not only did Japanese authorities ignore him, but some reprocessing advocates claim that the Obama administration in fact supports Japan’s plutonium recycling program.

Japan insists that its stockpiles are safe, but just one successful theft by would-be nuclear terrorists would create a global crisis. Of even more concern is how reprocessing provides cover for other countries to acquire a nuclear option.

We learned this in 1974 when India took plutonium enriched with help from the American Atoms for Peace program and used it for “peaceful nuclear explosion.”

Thanks to sustained diplomatic efforts, starting with Secretary of State Henry A. Kissinger, and to the high cost of reprocessing, Japan is the only non-nuclear state that continues to reprocess its nuclear fuel. South Korea is insisting, however, in its negotiation of a new Agreement of Nuclear Cooperation with the United States, that it should have the same right to reprocess as Japan.

South Korea isn’t alone. South Africa’s energy minister recently reasserted her country’s interest in reprocessing. When asked

why the country would want to embark on such a costly venture, a South African nuclear official once responded, “Reprocessing is the currency of power in the modern world!” Meanwhile, Iran insists that it has the same rights as Japan and is building a reactor similar to the one India used to produce the plutonium for its first nuclear bombs.

Despite the added cost of reprocessing — about $2.5 billion a year for the new facility — Japan insists it is the only viable option for the spent nuclear fuel which is filling up the cooling pools at its reactors. But there are easier alternatives.

When nuclear power plants in most other countries need space in their pools, they remove some of the older, cooler fuel and place it in air-cooled casks within the plant’s security perimeter. That costs 5 percent as much as reprocessing does. Eventually, the spent fuel is to be shipped to an underground repository, as is to be done with the high-level radioactive waste from reprocessing.

Reprocessing advocates in Japan and South Korea say that communities around the nuclear power plants will not allow dry-cask

storage and that, when the spent fuel pools fill up, the power plants will have to shut down.

But in both countries those local governments receive large subsidies and taxes — typically 50 percent of a municipality’s revenue in Japan — for playing host to nuclear power plants. They are unlikely to force permanent shutdowns just because they don’t like extra spent fuel kept at the reactor site, especially if the safety advantages of dry-cask storage are explained to them.

The Obama administration should make it emphatically clear to Japan’s government that the separation of more plutonium is in no one’s interest. The two countries should instead jointly lead a global effort to reduce existing stocks of separated plutonium by discouraging reprocessing and encouraging safe disposal of already separated stocks, which could be done, for example, by immobilizing the plutonium and placing it in three-mile-deep boreholes.

The waste of trillions of taxpayers’ yen is Japan’s problem. The risk it presents, however, is the whole world’s concern.

Frank N. von Hippel is a professor of public and international affairs at Princeton. Masafumi Takubo is a nuclear policy analyst based in Japan.

Other relevant info is available from the Nuclear Regulatory Commission:

Storage of Spent Nuclear Fuel in Pools and Dry Casks

    Radioactive Waste: Production, Storage, Disposal
    Materials Safeguards and Threat Assessment
    Transportation of Spent Nuclear Fuel
    Locations of Independent Spent Fuel Storage Installations
    Dry Spent Fuel Storage Designs: NRC Approved for General Use
    Nuclear Fuel Pool Capacity
What We Regulate

There are two acceptable storage methods for spent fuel after it is removed from the reactor core:

    Spent Fuel Pools - Currently, most spent nuclear fuel is safely stored in specially designed pools at individual reactor sites around the country.
    Dry Cask Storage - If pool capacity is reached, licensees may move toward use of above-ground dry storage casks.

For additional information, see our Spent Fuel Storage in Pools and Dry Casks, Key Points and Questions & Answers page.

How We Regulate

The NRC regulates spent fuel through a combination of regulatory requirements, licensing; safety oversight, including inspection, assessment of performance; and enforcement; operational experience evaluation; and regulatory support activities.

For general information, see the How We Regulate page. For details, see the following:

    Regulations, Guidance, and Communications
    Public Involvement
    Waste Confidence

Page Last Reviewed/Updated Thursday, October 18, 2012

Finally, from the World Nuclear Association / Representing the people and organizations of the global nuclear alliance (a nuclear trade association)

Megatons to Megawatts /  Military Warheads as a Source of Nuclear Fuel   (last updated Aug, 2011)

•    Weapons-grade uranium and plutonium surplus to military requirements in the USA and Russia is being made available for use as civil fuel.

•    Weapons-grade uranium is highly enriched, to over 90% U-235 (the fissile isotope). Weapons-grade plutonium has over 93% Pu-239 and can be used, like reactor-grade plutonium, in fuel for electricity production.

•    Highly-enriched uranium from weapons stockpiles is displacing some 10,600 tonnes of U3O8 production from mines each year, and meets about 13% of world reactor requirements.

For more than three decades concern has centered on the possibility that uranium intended for commercial nuclear power might be diverted for use in weapons. Today, however, attention is focused on the role of military uranium as a major source of fuel for commercial nuclear power.

Since 1987 the United States and countries of the former USSR have signed a series of disarmament treaties to reduce the nuclear arsenals by about 80%.

Nuclear materials declared surplus to military requirements by the USA and Russia are now being converted into fuel for commercial nuclear reactors. The main material is highly enriched uranium (HEU), containing at least 20% uranium-235 (U-235) and usually about 90% U-235. HEU can be blended down with uranium containing low levels of U-235 to produce low enriched uranium (LEU), typically less than 5% U-235, fuel for power reactors. It is blended with depleted uranium (mostly U-238), natural uranium (0.7% U-235), or partially-enriched uranium.

Highly-enriched uranium in US and Russian weapons and other military stockpiles amounts to about 2000 tonnes, equivalent to about twelve times annual world mine production.

World stockpiles of weapons-grade plutonium are reported to be some 260 tonnes, which if used in mixed oxide fuel in conventional reactors would be equivalent to a little over one year's world uranium production. Military plutonium can blended with uranium oxide to form mixed oxide (MOX) fuel.

After LEU or MOX is burned in power reactors, the spent fuel is not suitable for weapons manufacture.

Any questions?!