Immobilization and geological disposal of nuclear fuel waste

The Canadian Nuclear Fuel Waste Management Program is developing methods for the safe disposal of both used nuclear fuel and fuel recycle waste. The disposal strategy is based on interim storage of the used fuel, immobilization of either used fuel or recycle waste, and disposal, deep in a stable geological formation in the Canadian Shield. The disposal concept proposes a multibarrier system to inhibit the release of the radioactive waste from the disposal vault. The principal components of the multibarrier system are (i) the waste form in which the radionuclides are immobilized, (ii) engineered barriers including high integrity containers, buffers and backfills designed to retard the movement of groundwaters in the disposal vault, and (iii) the natural barrier provided by the massive geological formation itself. The research programs to investigate this concept are discussed briefly. Several different waste forms are being developed for the immobilization of high-level fuel recycle waste, including glass, glass-ceramics and crystalline materials. Dissolution of these materials in groundwater is the only likely scenario that could lead to radionuclide release. The factors that influence the aqueous dissolution behaviour of these materials are reviewed.     

Nuclear equivalence, nuclear transfer, and the cell cycle

The last 20 years have seen the development of techniques for the production of mammals by nuclear transfer. Originally limited to the swapping of pronuclei and the use of early cleavage-stage embryos as nuclear donors, nuclear transfer came of age in 1995 with the birth of 2 Welsh Mountain lambs, Megan and Morag, that were produced using cultured differentiated cells as donors of genetic material. In 1996, Dolly was the first animal to be produced using the genetic material from an adult-derived somatic cell. The techniques used in the production of these animals have now been reproduced in both sheep and cattle, and as predicted, successful development has been obtained using donor cells taken directly ex vivo. This article reviews the current status of mammalian nuclear transfer and the biological background to these successes.     

The incorporation of waste prevention activities into life cycle assessments of municipal solid waste management systems: methodological issues

Background, aim, and scope  

Municipal solid waste (MSW) management organizations commonly address both waste treatment and diversion activities in their management plans, yet the application of life cycle assessment (LCA) to MSW rarely incorporates the effects of waste prevention activities (WPAs) in an explicit manner. The primary objective of this paper is to further develop the methodological options for attributional LCAs of MSW to address waste prevention, including product reuse.     

The new law of the sea and the pacific basin

Abstract

The UN Convention on the Law of the Sea is indispensable for the well‐being of the states, especially the new island states, of the Pacific Basin. Since the Treaty will be signed at Caracas in December 1982, it is important to anticipate its impact in the Pacific Region area. The article examines the need for a new ocean law to replace the old law of the Geneva Conventions. It argues that exploitation of manganese nodules in the “Area”; will be legal only under the rules of Part XI of the Convention and that the principles of the Common Heritage of Mankind are now part of customary law. Finally, the seaward expansion of Pacific states authorized in the new treaty both necessitates, and provides an opportunity for, coordinated planning for the management of ocean resources and usages.     

A survey of life cycle approaches in waste management

Background, aim, and scope  

Life-cycle thinking and life-cycle approaches are concepts that are getting increased attention worldwide and in particular in EU Policies related to sustainability. The European Commission is launching a number of activities to strengthen life-cycle thinking in policy and business. EU policies aim to decrease waste generation through new waste prevention initiatives, better use of resources and shift to more sustainable consumption patterns. The approach to waste management is based on three principles: waste prevention, recycling and reuse and improving the final disposal and monitoring. In particular, concerning the prevention and recycling of waste, the definition of a waste hierarchy should be the basis for the prioritisation of waste management options. The benefit of using Life Cycle Assessment (LCA) in analysing waste management systems is the provision of a comprehensive view of the processes and impacts involved. However, it is also clear that the studies will always be open for criticism as they are simplifications of reality. Moreover, in order to become the LCA, a leading tool within businesses and government to understand and manage risks or opportunities related to waste management and treatment technologies, there are methodological choices required and a number of aspects that still need to be worked out. It is therefore important to review open and grey literatures, EU guidelines, relevant environmental indicators and databases for the waste sector and data easily usable in waste policy decision-making, with an agreed approach and methodology based on life-cycle thinking. The following survey gathers and describes the existing guidelines and methodologies based on life-cycle thinking and applicable in waste policy decision-making.     

Discussion on methods to include prevention activities in waste management LCA

Purpose

Waste prevention has been assigned increasing attention worldwide during recent years, and it is expected to become one of the core elements of waste management planning in the near future. In this framework, this paper presents and discusses two possible LCA approaches for the evaluation of the environmental and energetic performance of municipal solid waste (MSW) management systems which include the effects of waste prevention activities.

Methods

The two approaches are conceived for the comparison of waste management scenarios including waste prevention activities with baseline scenarios without waste prevention. For both of them, the functional unit is defined and the system boundaries are described with reference to different typologies of waste prevention activities identified in an extensive review. The procedure for the calculation of the LCA impacts of scenarios is also reported and an example illustrating the processes to be included in system boundaries for a specific waste prevention activity is provided.

Results and discussion

The presented approaches lead to the same result in terms of difference between the LCA impacts of a waste prevention scenario and of a baseline one. However, because of the partially different upstream system boundaries, different values of the impacts of single scenarios are obtained and the application of the two approaches is more suitable in different situations and in analyses with different purposes. The methodological aspects that can complicate the applicability of the two approaches are discussed lastly.

Conclusions

The environmental and energetic performance of MSW management scenarios including waste prevention activities can be evaluated with the two LCA approaches presented in this paper. They can be used for many purposes such as, among the most general, evaluating the upstream and downstream environmental consequences of implementing particular waste prevention activities in a given waste management system, complementing waste reduction indicators with LCA-based indicators and supporting with quantitative evidence the strategic and policy relevance of waste prevention.     

The legitimacy of life cycle assessment in the waste management sector

Purpose

Life cycle assessment (LCA) is commonly presented as a tool for rational decision-making. It has been increasingly used to support decision-making in situations where multiple actors possess diverse, and sometimes conflicting, perspectives, values and motives. Yet, little effort has been placed on understanding LCA in a social framework of action. This paper aims to analyse the legitimacy of LCA in public sector decision-making situations, the criticisms presented against LCA, and suggest potential ways to alleviate these criticisms.

Methods

This study consists of a case study of the application of LCA in the waste management sector in England and France. To gain an understanding of the justification and criticism of LCA, semi-structured interviews were undertaken with national and local level waste management actors. The justifications and criticism of the application of LCA was analysed through an analytical framework, the economies of worth. This suggests that in situations of disagreement, actors’ justifications are required to show their attachment to plural forms of common good. This work analyses the orders of worth in which justifications and criticisms of the application of LCA were based.

Results and discussion

LCA is applied primarily as a test of environmental efficiency, illustrating a collaboration between the industrial and green orders of worth. Actors apply LCA with the aspiration of replicating the scientific method and producing robust evidence to support the most efficient waste treatment option. In this case, efficiency is coupled with the green order of worth, where gains in efficiency mean lower environmental impacts. Internal criticisms of LCA, based in the industrial order of worth, highlights the limitations of LCA to act as a test of environmental efficiency. Furthermore, criticism based in the civic order of worth highlights the friction which arises in decision-making situations when LCA has been seen to subjugate the civic nature of waste management decisions.

Conclusions

One potential way forward for LCA may be to introduce aspects relevant in the civic order of worth which aims at achieving a compromise between the industrial and civic orders of worth. Envisioning LCA as a process-oriented tool, as opposed to an outcome-oriented tool, can allow for aspects on public involvement in the LCA process, thereby increasing its civic legitimacy.

     

A life cycle assessment of residential waste management and prevention

Purpose

The oft-cited waste hierarchy is considered an important rule of thumb to identify preferential waste management options and places waste prevention at the top. Nevertheless, it has been claimed that waste prevention can sometimes be less favorable than recycling because (1) recycling decreases only the primary production of materials, whereas waste prevention may reduce a combination of both primary and low-impact secondary production, and (2) waste prevention decreases the quantity of material recycled downstream and the avoided impacts associated with recycling. In response to this claim, this study evaluates the life cycle effects of waste prevention activities (WPAs) on a residential waste management system.

Methods

This life cycle assessment (LCA) contrasts the net impacts of a large residential solid waste management system (including sanitary landfilling, anaerobic digestion, composting, and recycling) with a system that incorporates five WPAs, implemented at plausible levels (preventing a total of 3.6 % of waste generation tonnage) without diminishing product service consumption. WPAs addressed in this LCA reduce the collected tonnage of addressed advertising mail, disposable plastic shopping bags, newspapers, wine and spirit packaging, and yard waste (grass).

Results and discussion

In all cases, the WPAs reduce the net midpoint and endpoint level impacts of the residential waste management system. If WPAs are incorporated, the lower impacts from waste collection, transportation, sorting, and disposal as well as from the avoided upstream production of goods, more than compensate for the diminished net benefits associated with recycling and the displaced electricity from landfill gas utilization.

Conclusions

The results substantiate the uppermost placement of waste prevention within the waste hierarchy. Moreover, further environmental benefits from waste prevention can be realized by targeting WPAs at goods that will be landfilled and at those with low recycled content.     

生命周期评价方法在城市生活垃圾管理中的应用研究述评

结合城市生活垃圾管理系统特征,系统归纳基于生命周期评价(Life cycle assessment,LCA)方法的城市生活垃圾管理模型的发展现状,并对LCA方法在城市生活垃圾管理中的实践以及在我国开展城市生活垃圾管理LCA研究的应用前景进行评述。分析表明,LCA是城市生活垃圾管理领域的重要工具之一,基于LCA方法的城市生活垃圾管理模型在全生命周期环境影响评价与识别、处置工艺选择与改进、可持续生活垃圾管理决策支持等方面具有十分重要的应用价值。中国在本地化生活垃圾管理系统LCA模型开发、清单数据库和评价指标体系构建以及与其他研究方法集成等方面面临挑战。     

Nuclear protein kinase activities during the cell cycle of HeLa S3 cells

To ascertain the activity and substrate specificity of nuclear protein kinases during various stages of the cell cycle of HeLa S3 cells, a nuclear phospho-protein-enriched sample was extracted from synchronised cells and assayed in vitro in the presence of homologous substrates. The nuclear protein kinases increased in activity during S and G2 phase to a level that was twice that of kinases from early S phase cells. The activity was reduced during mitosis but increased again in G1 phase. When the phosphoproteins were separated into five fractions by cellulose-phosphate chromatography each fraction, though not homogenous, exhibited differences in activity. Variations in the activity of the protein kinase fractions were observed during the cell cycle, similar to those observed for the unfractionated kinases. Sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis of the proteins phosphorylated by each of the five kinase fractions demonstrated a substrate specificity. The fractions also exhibited some cell cycle stage-specific preference for substrates; kinases from G1 cells phosphorylated mainly high molecular weight polypeptides, whereas lower molecular weight species were phosphorylated by kinases from the S, G2 and mitotic stages of the cell cycle. Inhibition of DNA and histone synthesis by cytosine arabinoside had no effect on the activity or substrate specificity of S phase kinases. Some kinase fractions phosphorylated histones as well as non-histone chromosomal proteins and this phosphorylation was also cell cycle stage dependent. The presence of histones in the in vitro assay influenced the ability of some fractions to phosphorylate particular non-histone polypeptides; non-histone proteins also appeared to affect the in vitro phosphorylation of histones.     

Reliability-based life cycle assessment for future solid waste management alternatives in Portugal

Background, aim, and scope  

This paper presents a study related to the application of the reliability-based life cycle assessment (LCA) to assess different alternatives for solid waste management in the Setúbal peninsula, Portugal. The current system includes waste collection, transport, sorting, recycling, and mechanical and biological treatment (MBT) by means of aerobic treatment and landfill. In addition, some future expansion plans are discussed.     

Life-cycle greenhouse gas inventory analysis of household waste management and food waste reduction activities in Kyoto, Japan

Purpose

Source-separated collection of food waste has been reported to reduce the amount of household waste in several cities including Kyoto, Japan. Food waste can be reduced by various activities including preventing edible food loss, draining moisture, and home composting. These activities have different potentials for greenhouse gas (GHG) reduction. Therefore, we conducted a life-cycle inventory analysis of household waste management scenarios for Kyoto with a special emphasis on food waste reduction activities.

Methods

The primary functional unit of our study was ??annual management of household combustible waste in Kyoto, Japan.?? Although some life-cycle assessment scenarios included food waste reduction measures, all of the scenarios had an identical secondary functional unit, ??annual food ingestion (mass and composition) by the residents of Kyoto, Japan.?? We analyzed a typical incineration scenario (Inc) and two anaerobic digestion (dry thermophilic facilities) scenarios involving either source-separated collection (SepBio) or nonseparated collection followed by mechanical sorting (MecBio). We assumed that the biogas from anaerobic digestion was used for power generation. In addition, to evaluate the effects of waste reduction combined with separate collection, three food waste reduction cases were considered in the SepBio scenario: (1) preventing loss of edible food (PrevLoss); (2) draining moisture contents (ReducDrain); and (3) home composting (ReducHcom). In these three cases, we assumed that the household waste was reduced by 5%.

Results and discussion

The GHG emissions from the Inc, MecBio, and SepBio scenarios were 123.3, 119.5, and 118.6 Gg CO₂-eq/year, respectively. Compared with the SepBio scenario without food waste reduction, the PrevLoss and ReducDrain cases reduced the GHG emissions by 17.1 and 0.5 Gg CO₂-eq/year. In contrast, the ReducHcom case increased the GHG emissions by 2.1 Gg CO₂-eq/year. This is because the biogas power production decreased due to the reduction in food waste, while the electricity consumption increased in response to home composting. Sensitivity analyses revealed that a reduction of only 1% of the household waste by food loss prevention has the same GHG reduction effect as a 31-point increase (from 50% to 81%) in the food waste separation rate.

Conclusions

We found that prevention of food losses enhanced by separate collection led to a significant reduction in GHG emissions. These findings will be useful in future studies designed to develop strategies for further reductions in GHG emissions.     

Nuclear translocation of phospholipase C-delta1 is linked to the cell cycle and nuclear phosphatidylinositol 4,5-bisphosphate

Nuclear phosphoinositides, especially phosphatidylinositol 4,5-bisphosphate, fluctuate throughout the cell cycle and are linked to proliferation and differentiation. Here we report that phospholipase C-delta(1) accumulates in the nucleus at the G(1)/S boundary and in G(0) phases of the cell cycle. Furthermore, as wild-type protein accumulated in the nucleus, nuclear phosphatidylinositol 4,5-bisphosphate levels were elevated 3-5-fold, whereas total levels were decreased compared with asynchronous cultures. To test whether phosphatidylinositol 4,5-bisphosphate binding is important during this process, we introduced a R40D point mutation within the pleckstrin homology domain of phospholipase C-delta(1), which disables high affinity phosphatidylinositol 4,5-bisphosphate binding, and found that nuclear translocation was significantly reduced at G(1)/S and in G(0). These results demonstrate a cell cycle-dependent compartmentalization of phospholipase C-delta(1) and support the idea that relative levels of phosphoinositides modulate the portioning of phosphoinositide-binding proteins between the nucleus and other compartments.     

Nuclear antigens in the HeLa cell cycle

Summary Antisera to 0.35 M NaCl extracts and residues of S phase HeLa nuclei were reacted with electrophoretically separated proteins from the nuclei or nuclear material of HeLa cells synchronized in G₁, S, G₂ or M phases of the cell cycle. Quantitative evaluation of the peroxidase-antiperoxidase stained nitrocellulose transfers (Western blots) revealed significant changes in the quantities of nuclear non-histone proteins during the cell cycle. Immunochemical staining of electrophoretically separated nuclear antigens permits their selective detection in minute quantities and in the presence of many additional proteins.     

Life cycle impact assessment and interpretation of municipal solid waste management scenarios based on the midpoint and endpoint approaches

Purpose  

Few studies have examined differing interpretations of life cycle impact assessment (LCIA) results between midpoints and endpoints for the same systems. This paper focuses on the LCIA of municipal solid waste (MSW) systems by taking both the midpoint and endpoint approaches and uses LIME (Life Cycle Impact Assessment Method based on Endpoint Modeling, version 2006). With respect to global and site-dependent factors, environmental impact categories were divided into global, regional, and local scales. Results are shown as net emissions consisting of system emissions and avoided emissions.     

Nuclear division and chromosome cycle in microsporidia

Nuclear division and chromosome cycle of microsporidia are reviewed in the light of recent speculation that the group diverged as an early branch in the eukaryotic line of descent. Microsporidia are primitive eukaryotes with simple cytoplasmic organisation, lacking mitochondria, peroxisomes and a classical Golgi apparatus. The ribosomes resemble prokaryotic ribosomes in size and in having sequences complementary to the eukaryotic 5.8S rRNA contained within their large (23S) ribosomal subunit, rather than a separate 5.8S molecule. Nuclei may be isolated or closely appressed as a diplokaryotic pair which divide synchronously. Mitosis is intranuclear: there are no centrioles but spindle termini are electron dense plaques in pores in the nuclear envelope. Some genera have isolated nuclei throughout the life cycle, while others have diplokaryotic nuclei throughout: meiosis is not known in either of these categories of genera. In contrast, certain polymorphic species, which are transmitted horizontally between copepods and mosquitoes and vertically between generations of mosquitoes, alternate between stages with isolated nuclei and stages with diplokaryotic nuclei. Haploid spores in copepods are infective to mosquito larvae, in which gametogenesis and plasmogamy occur to give diplokaryotic (diploid) stages. Stages remain diplokaryotic through transovarial transmission to the next generation, when an unusual form of meiosis is initiated in both nuclei of the diplokaryon (as indicated by synaptonemal complexes), and mingling of chromosomes occurs when the two nuclei fuse during pachytene.