Fission-gas-release rates from irradiated uranium nitride specimens

Fission-gas-release rates from two 93 percent dense UN specimens were measured using a sweep gas facility. Specimen burnup rates averaged .0045 and .0032 percent/hr, and the specimen temperatures ranged from 425 to 1323 K and from 552 to 1502 K, respectively. Burnups up to 7.8 percent were achieved. Fission-gas-release rates first decreased then increased with burnup. Extensive interconnected intergranular porosity formed in the specimen operated at over 1500 K. Release rate variation with both burnup and temperature agreed with previous irradiation test results

Testing of uranium nitride fuel in T-111 cladding at 1200 K cladding temperature

Two groups of six fuel pins each were assembled, encapsulated, and irradiated in the Plum Brook Reactor. The fuel pins employed uranium mononitride (UN) in a tantalum alloy clad. The first group of fuel pins was irradiated for 1500 hours to a maximum burnup of 0.7-atom-percent uranium. The second group of fuel pins was irradiated for about 3000 hours to a maximum burnup of 1.0-atom-percent uranium. The average clad surface temperature during irradiation of both groups of fuel pins was approximately 1200 K. The postirradiation examination revealed the following: no clad failures or fuel swelling occurred; less than 1 percent of the fission gases escaped from the fuel; and the clad of the first group of fuel pins experienced clad embrittlement whereas the second group, which had modified assembly and fabrication procedures to minimize contamination, had a ductile clad after irradiation

Collapse of the world's largest herbivores

Large wild herbivores are crucial to ecosystems and human societies. We highlight the 74 largest terrestrial herbivore species on Earth (body mass ≥100 kg), the threats they face, their important and often overlooked ecosystem effects, and the conservation efforts needed to save them and their predators from extinction. Large herbivores are generally facing dramatic population declines and range contractions, such that ~60% are threatened with extinction. Nearly all threatened species are in developing countries, where major threats include hunting, land-use change, and resource depression by livestock. Loss of large herbivores can have cascading effects on other species including large carnivores, scavengers, mesoherbivores, small mammals, and ecological processes involving vegetation, hydrology, nutrient cycling, and fire regimes. The rate of large herbivore decline suggests that ever-larger swaths of the world will soon lack many of the vital ecological services these animals provide, resulting in enormous ecological and social costs

Environmental Research Plan for Natural Resource Management Organisations and Regional Development Australia Boards in Northern Australia: NERP TE Hub Project CF14 final report

[Extract] This report presents an environmental research plan for Natural Resource Management (NRM) organisations and Regional Development Australia (RDA) boards across northern Australia. It includes priority knowledge needs and governance arrangements necessary to address them. The plan aims to assist the Australian Department of Environment to formulate its national environmental research priorities and design its National Environmental Science Program (NESP). The plan also, however, provides a platform from which all groups can progress a long term research agenda beyond NESP investment

Supplementary Document to 'Environmental Research Plan for Natural Resource Management Organisations and Regional Development Australia Boards in Northern Australia: NERP TE Project CF14'

[Extract] This report provides supplementary information describing the preparation of "An Environmental Research Plan for Natural Resource Management Organisations and Regional Development Australia Boards in Northern Australia". The plan was complied in collaboration with 11 Natural Resource Management (NRM) groups and seven Regional Development Australia (RDA) boards from northern Western Australia, the Northern Territory and northern Queensland

Supplementary Document to 'Environmental Research Plan for Natural Resource Management Organisations and Regional Development Australia Boards in Northern Australia: NERP TE Project CF14'

[Extract] This report provides supplementary information describing the preparation of "An Environmental Research Plan for Natural Resource Management Organisations and Regional Development Australia Boards in Northern Australia". The plan was complied in collaboration with 11 Natural Resource Management (NRM) groups and seven Regional Development Australia (RDA) boards from northern Western Australia, the Northern Territory and northern Queensland