Reprocessing Of Plutonium Research Articles

The ‘conceit of controllability’: nuclear diplomacy, Japan’s plutonium reprocessing ambitions and US proliferation fears, 1974-1978

ABSTRACT US-Japanese nuclear diplomacy on plutonium reprocessing was a means by which both attempted to assert control. For Japan, this meant control over its energy supplies and the status associated with advanced nuclear power technology. Japan had emerged as an economic giant but had accepted a diminution in status by adhering to the Non-Proliferation Treaty (NPT) and was determined not to have its access to cutting edge nuclear power technology curtailed. The US sought to control the spread of a technology which would produce plutonium and consequently, it was feared, increase the chances of weapons proliferation. Washington’s diplomatic gambit, the International Nuclear Fuel Cycle Evaluation, attempted to use ‘neutral’ science for political ends. However, Tokyo was able to ally with partners to frustrate Washington’s ambitions. In the long-term Japan did not score a victory since the hopes of reprocessing were not realized. Ultimately, neither was able to assert control.

Extension of the Plutonium Oxide Nanocluster Family to Include {Pu16 } and {Pu22 }.

Plutonium(IV) oxide nanoclusters represent an interesting scientific problem regarding structure-function relationships and are also relevant to global concerns surrounding plutonium reprocessing, the remediation of plutonium-contaminated soils, and the storage or disposal of plutonium-containing wastes. Here we report the synthesis of five unique PuIV oxide nanoclusters containing 38, 22, or 16 metal centers and capped only with inorganic ligands, such as chlorine and water, which prevent formation of the extended PuO2 structure. The products are interrogated through single-crystal X-ray diffraction, bond valence calculations, and comparisons to other known metal-oxide nanoclusters. Of particular interest is the incorporation of hydroxide linkages into the smaller plutonium oxide nanoclusters, which underscores previous observations and hypotheses regarding the formation of plutonium polymers and colloids.

Plutonium reprocessing, breeder reactors, and decades of debate

Some observers believe that plutonium reprocessing is on the verge of an expansion, while others argue that the end of the practice is in sight. The risk of nuclear proliferation has always been the chief objection to reprocessing but proponents argue that today, with uranium enrichment technology more easily available, reprocessing no longer represents an efficient route toward nuclear weapons. Supporters also tout the energy security that reprocessing could provide to nations without indigenous uranium sources and the reductions in high-level nuclear waste that reprocessing might achieve. Opponents counter that reprocessing offers only marginal benefits in waste reduction and in any event makes little economic sense. Here, Klaus Janberg of Germany (2015), Baldev Raj and P. R. Vasudeva Rao of India, and Hui Zhang of China (2015) debate how nations—taking into account issues ranging from proliferation to waste to cost—should approach plutonium reprocessing.

Plutonium reprocessing, breeder reactors, and decades of debate

Some observers believe that plutonium reprocessing is on the verge of an expansion, while others argue that the end of the practice is in sight. The risk of nuclear proliferation has always been the chief objection to reprocessing but proponents argue that today, with uranium enrichment technology more easily available, reprocessing no longer represents an efficient route toward nuclear weapons. Supporters also tout the energy security that reprocessing could provide to nations without indigenous uranium sources and the reductions in high-level nuclear waste that reprocessing might achieve. Opponents counter that reprocessing offers only marginal benefits in waste reduction and in any event makes little economic sense. Here, Klaus Janberg of Germany (2015), Baldev Raj and P. R. Vasudeva Rao of India (2015), and Hui Zhang of China debate how nations—taking into account issues ranging from proliferation to waste to cost—should approach plutonium reprocessing.

Plutonium reprocessing, breeder reactors, and decades of debate

Some observers believe that plutonium reprocessing is on the verge of an expansion, while others argue that the end of the practice is in sight. The risk of nuclear proliferation has always been the chief objection to reprocessing but proponents argue that today, with uranium enrichment technology more easily available, reprocessing no longer represents an efficient route toward nuclear weapons. Supporters also tout the energy security that reprocessing could provide to nations without indigenous uranium sources and the reductions in high-level nuclear waste that reprocessing might achieve. Opponents counter that reprocessing offers only marginal benefits in waste reduction and in any event makes little economic sense. Here, Klaus Janberg of Germany, Baldev Raj and P. R. Vasudeva Rao of India (2015), and Hui Zhang of China (2015) debate how nations—taking into account issues ranging from proliferation to waste to cost—should approach plutonium reprocessing.

Site selectivity of dopant cations in Ca3(SiO4)Cl2

A series of static lattice calculations were performed to determine the site selectivity of cations of differing size and valence when substituted onto the Ca sites of the calcium chlorosilicate (Ca3(SiO4)Cl2) lattice, a potential host phase for the immobilisation of halide-rich wastes arising from the pyrochemical reprocessing of plutonium. Atomic-scale simulations indicate that divalent cations are preferentially substituted onto the Ca1 site, whilst tri- and tetravalent cations are preferentially hosted on the Ca2 site, with the Ca1 site favoured for forming the vacancies necessary to charge-balance the lattice as a whole. Multi-defect calculations reveal that the site selectivity of the dopant cations is dependent on their ionic radii; as the ionic radii of the divalent cations increase, substitution onto the preferred site becomes more and more strongly favoured, whereas the inverse is true of the trivalent cations.

European Efforts to Control the Spread of Enrichment and Reprocessing Technologies

EU efforts to foster agreement on better measures to prevent the misuse of uranium enrichment and plutonium reprocessing (ENR) technologies are an easy test for the effectiveness European policies to improve controls over proliferation-sensitive technologies more generally. Three examples of attempts to strengthen ENR controls are examined. EU members and the EU were actively engaged in efforts to peacefully resolve the conflict over Iran’s nuclear program, in the strengthening of guidelines of the Nuclear Suppliers Groups for the trade in ENR technologies and in endeavours to develop multilateral approaches for enrichment and reprocessing facilities. Yet, European efforts suffered from the same lack of coherence that characterizes the EU’s non-proliferation policies more generally. Realistically, it will be up to EU member states and particularly those with access to ENR technologies to provide political leadership on nuclear non-proliferation issues such as better ENR controls.

Aging Studies of Pu-238 and -239 Containing Calcium Phosphate Ceramic Waste-forms

ABSTRACTA calcium phosphate ceramic waste-form has been developed at AWE for the immobilisation of chloride containing wastes arising from the pyrochemical reprocessing of plutonium. In order to determine the long term durability of the waste-form, aging trials have been carried out at PNNL. Ceramics were prepared using Pu-239 and -238, these were characterised by PXRD at regular intervals and Single Pass Flow Through (SPFT) tests after approximately 5 yrs.While XRD indicated some loss of crystallinity in the Pu-238 samples after exposure to 2.8 x 1018 α decays, SPFT tests indicated that accelerated aging had not had a detrimental effect on the durability of Pu-238 samples compared to Pu-239 waste-forms.

A Comparison of Alumino and Calcium Phosphate Sintering Aids for Consolidation of Halide Containing Wastes

ABSTRACTA process has been developed at AWE for the immobilisation of halide containing wastes arising from the reprocessing of plutonium. Initially, the wastes are calcined with a calcium phosphate to form a number of target host phases, β-tricalcium phosphate (β-TCP) and apatite for the immobilisation of actinides, and apatite and spodiosite for halide.These mineral phases are then mixed with a glass binder, cold pressed and sintered to form a monolithic waste form. Two glass binders GTI/168, a sodium alumino phosphate glass and GTI/206, a sodium calcium phosphate glass were compared to optimise the halide retention in the waste-form. Analysis from powder X-ray Diffraction (PXRD) and scanning electron microscopy (SEM) showed that neither glass stabilises spodiosite. However, GTI/206 glass retains 10 wt.% more apatite and results in a much smaller proportion of the non-chloride bearing whitlockite phase than GTI/168.In all compositions where GTI/168 glass was used as a sintering aid, the sodium deficient and calcium enriched glass was present as an amorphous matrix phase.

Nuclear energy expansion in the Middle East

A statement on 31 October by a senior official of the International Atomic Energy Agency, indicating that six Arab states have shown interest in nuclear power, has provoked concerns that Iran’s apparent pursuit of nuclear weapons capabilities may be prompting some of its neighbours to think about doing the same. Building up a nuclear power infrastructure might be part of a future hedging strategy. However, it is important to distinguish between the proliferation-prone parts of the nuclear fuel cycle that give rise to fears about Iran’s intentions – uranium enrichment and plutonium reprocessing – and the benign civil nuclear energy purposes that have been under study in the Middle East for some time.

Immobilization of Simulant ILW Actinide Wastes Containing Halides: Effect of Process Parameters on Wasteform Properties

ABSTRACTThe applicability of a process, originally developed to immobilize a chloride-rich intermediate level waste (ILW) arising from the pyrochemical reprocessing of plutonium, to alternative ILW waste-streams containing a large variety of cations, present as oxides together with KCl and CaF2, has been investigated. Non-radioactive studies, using simulated wastes containing hafnium and samarium as surrogates for the actinides, have been performed to establish the optimum processing parameters for the manufacture of wasteforms suitable for long-term storage/disposal. It has been demonstrated that the wastes can be immobilized by calcining with either Ca3(PO4)2 or CaHPO4 as the host. In excess of 97.5 % of the chloride present in calcined wastes, containing up to 3.2 wt% halides as a mixture of F- and Cl-, is immobilized when using this process. Whereas in the original calcined waste, the Cl- (about 12 wt%) was immobilized as chlorapatite, Ca5(PO4)3Cl, and spodiosite, Ca2(PO4)Cl, in these current wastes fluorapatite is the predominant halide containing phase. Conversion of the immobilized waste powder into a monolithic wasteform was achieved by sintering the powder with the addition of a sodium aluminium phosphate based glass. Both the calcined powder and the sintered monolithic wasteforms showed excellent durability in aqueous solution.

Development of a Phosphate Ceramic as a Host for Halide-contaminated Plutonium Pyrochemical Reprocessing Wastes

AbstractThe presence of halide anions in four types of wastes arising from the pyrochemical reprocessing of plutonium required an immobilization process to be developed in which not only the actinide cations but also the halide anions were immobilized in a durable, leach resistant form. AWE has developed such a process using Ca3(PO4)2 as the host material. Successful trials of the process using actinide-doped Type I waste (essentially a chloride-based waste) were carried out at PNNL where the immobilization of the waste in a form resistant to aqueous leaching was confirmed. Normalized mass losses determined using a modified MCC-1 test at 40°C/28 days were 12 x 10-6 g.m-2 and 2.7 x 10-3 g.m-2 for Pu and Cl, respectively. Accelerated radiation-induced damage effects are being determined with specimens containing 238Pu. No changes in the crystalline lattice have been detected with XRD after the 239Pu equivalent of 400 years ageing. Confirmation of the process for Type II waste (an oxyhydroxide-based waste) is currently underway at PNNL.Differences in the ionic state of plutonium in the four types of waste have required different surrogates to be used. Samarium chloride was used successfully as a surrogate for both Pu(III) and Am(III) chlorides. Early investigations into the use of HfO2 as the surrogate for Pu(IV) oxide in Type II waste showed some apparent differences in the phase assemblages of the surrogate and actinide-based products. However XRD examination of the products at higher resolution has demonstrated there is no significant difference and that for this work HfO2 is a suitable surrogate for PUO2.

Did North Korea Cheat?

ON OCTOBER 4, 2002, the United States suddenly confronted North Korea with a damning accusation: that it was secretly de veloping a program to enrich uranium to weapons grade, in violation of the 1994 agreement that Pyongyang had signed with Washington to freeze its pursuit of nuclear weapons. Since North Korea had cheated, the Bush administration declared, the United States was no longer bound by its side of the deal. Accordingly, on November 14, 2002, the United States and its allies suspended the oil shipments they had been providing North Korea under the 1994 agreement. Pyongyang retaliated by expelling international inspectors and re suming the reprocessing of plutonium, which it had stopped under the 1994 accord (known as the Agreed Framework). The confrontation between North Korea and the United States once more reached a crisis level. Much has been written about the North Korean nuclear danger, but one crucial issue has been ignored: just how much credible evidence is there to back up Washington's uranium accusation? Although it is now widely recognized that the Bush administration misrepresented and distorted the intelligence data it used to justify the invasion of Iraq, most observers have accepted at face value the assessments the administration has used to reverse the previously established U.S. policy toward North Korea.

Deep-Burn: making nuclear waste transmutation practical

In the Deep-Burn concept, destruction of the transuranic component of light water reactor (LWR) waste is carried out in one burn-up cycle, accomplishing the virtually complete destruction of weapons-usable materials (Plutonium-239), and up to 90% of all transuranic waste, including the near totality of Neptunium-237 (the most mobile actinide in the repository environment) and its precursor, Americium-241. Waste destruction would be performed rapidly, without multiple reprocessing of plutonium, thus eliminating the risks of repeated handling of weapons-usable material and limiting the generation of secondary waste. There appears to be no incentive in continuing the destruction of waste beyond this level. An essential feature of the Deep-Burn Transmuter is the use of ceramic-coated fuel particles that provide very strong containment and are highly resistant to irradiation, thereby allowing very extensive destruction levels (“Deep Burn”) in the one pass, using gas-cooled modular helium reactor (MHR) technology developed for high-efficiency energy production. The fixed moderator (graphite) and neutronically transparent coolant (helium) provide a unique neutron energy spectrum to cause Deep-Burn, and inherent safety features, specific to the destruction of nuclear waste, that are not found in any other design. Deep-Burn technology could be available for deployment in a relatively short time, thus contributing effectively to waste problem solutions. Extensive modeling effort has led to conceptual Deep-Burn designs that can achieve high waste destruction levels (70% in critical mode, 90% in with a supplemental subcritical step) within the operational envelope of commercial MHR operation, including long refueling intervals and the highly efficient production of energy (approximately 50%). To the plant operator, a Deep-Burn Transmuter will be identical to its commercial reactor counterpart.

Development Of A Glass-Encapsulated Ceramic Wasteform For The Immobilization Of Chloride-Containing ILW

ABSTRACTPyrochemical reprocessing of plutonium generates several ILW waste-streams and a simple process has been developed at AWE to immobilize the chloride and actinide ions present in one of these waste-streams (Type 1) by calcining the waste with calcium phosphate. We have now investigated the possibility of using this process as the basis for treating a more complex waste-stream (Type 2) and have determined that with some minor modification the original process can effectively immobilize the greater range of cations present in Type 2 waste to again produce a free-flowing non-hygroscopic powder. Weight for weight replacement of the Type 1 waste by Type 2 produced a powder which was approximately 20% deficient in PO43- when compared with stoichiometric powder. Addition of phosphorus pentoxide to the simulant waste/calcium phosphate powder mixture prior to calcination to produce stoichiometric powder significantly improved the chloride ion uptake. In order to comply with safety requirements it is necessary to convert the free-flowing powder into a monolithic wasteform suitable for long term storage. Conversion of the powder to a monolithic wasteform by sintering using a sodium aluminophosphate glass as a binder has been investigated and has proved successful, but to achieve high densities it has been necessary to cold press the samples prior to sintering.

Iran's nuclear procurement program: How close to the bomb?

(1997). Iran's nuclear procurement program: How close to the bomb? The Nonproliferation Review: Vol. 5, No. 1, pp. 123-135.

Russian whistleblower faces jail

Muscovite accuses Organic Chemistry Institute of chemical weapons work; Britain ponders the economic and political fallout of plutonium reprocessing

Nuclear power and weapons proliferation — The thin link

“Proliferation” — the current shorthand buzzword which describes the potential international spread of the production capability for nuclear weapons — has been a matter of national concern in the US since the closing days of World War II. But this recently-popularized concern now appears to be causing a reversal of a quarter century of US policy regarding the best means of preventing proliferation. Stimulated by the last presidential campaign, the US has been moving toward prohibiting, or severely restricting, domestic use of the civilian fuel cycle including plutonium reprocessing and postponing consequently the US breeder reactor option. This is being advocated on the ground that, if the US foregoes civilian reprocessing and use of plutonium and delays the breeder, other countries — energy-hungry though they may be — will voluntarily deprive themselves of the full benefit of nuclear energy to follow our “moral leadership.”