scholarly journals An Integrated Testing Program for a Near-Field Radionuclide Migration Code

1997 ◽  
Vol 506 ◽  
Author(s):  
P. Binks ◽  
A. Fairhurst ◽  
D. Howarth ◽  
P. N. Humphreys ◽  
T. Johnstone ◽  
...  
Keyword(s):  
Near Field ◽  
Field Studies ◽  
Test Cases ◽  
Radionuclide Migration ◽  
Near Surface ◽  
Transport Code ◽  
Liquid Source ◽  
Integrated Testing ◽  
Main Components

ABSTRACTThe DRINK code is a 2D, biogeochemical transport code developed as a research tool to simulate the long term evolution of near surface LLW disposal sites and to generate gaseous and liquid source terms for far field studies. The code was recently upgraded to provide a more generic modelling tool with wider application to radionuclide migration scenarios. During the development of this code, the Generalised Repository Model (GRM), an integrated strategy has been employed to ensure the production of a fully tested, verified and quality assured product. This strategy is based around a code development protocol with three main components: quality assurance and documentation, verification and realism testing. Realism testing includes both peer review and model testing, with the latter including: experimental test cases; natural and anthropogenic analogues; field observations and finally uncertainty and sensitivity analysis. This paper describes the successful application of the protocol to the development and testing of the GRM code with specific emphasis upon verification and realism testing.

scholarly journals Constraints and flexibility in mammalian social behaviour: introduction and synthesis

2013 ◽  
Vol 368 (1618) ◽  
pp. 20120337 ◽  
Author(s):  
Peter M. Kappeler ◽  
Louise Barrett ◽  
Daniel T. Blumstein ◽  
Tim H. Clutton-Brock
Keyword(s):  
Social Behaviour ◽  
Social Systems ◽  
50Th Anniversary ◽  
Field Studies ◽  
Social Constraints ◽  
Behavioural Flexibility ◽  
Theme Issue ◽  
Current State ◽  
Main Components

This paper introduces a Theme Issue presenting the latest developments in research on the interplay between flexibility and constraint in social behaviour, using comparative datasets, long-term field studies and experimental data from both field and laboratory studies of mammals. We first explain our focus on mammals and outline the main components of their social systems, focusing on variation within- and among-species in numerous aspects of social organization, mating system and social structure. We then review the current state of primarily ultimate explanations of this diversity in social behaviour. We approach the question of how and why the balance between behavioural flexibility and continuity is achieved by discussing the genetic, developmental, ecological and social constraints on hypothetically unlimited behavioural flexibility. We introduce the other contributions to this Theme Issue against this background and conclude that constraints are often crucial to the evolution and expression of behavioural flexibility. In exploring these issues, the enduring relevance of Tinbergen's seminal paper ‘On aims and methods in ethology’, with its advocacy of an integrative, four-pronged approach to studying behaviour becomes apparent: an exceptionally fitting tribute on the 50th anniversary of its publication.

Modelling of a Generic Near-Surface Disposal System

2012 ◽  
Vol 1475 ◽  
Author(s):  
Noelia R. Sileo ◽  
Néstor O. Fuentes
Keyword(s):  
Performance Assessment ◽  
Waste Disposal ◽  
Near Field ◽  
Simple Calculation ◽  
Radioactive Waste Disposal ◽  
Disposal Site ◽  
Near Surface ◽  
License Application ◽  
Numerical Tools

ABSTRACTDevelopment of numerical tools for performance assessment studies of radioactive waste disposal facilities, must address the management of the wide-ranging uncertainties associated with the long-term behaviour of these complex systems. Different approaches and assumptions are made in order to identify and describe relationships between the disposal system and its environment. They take into account, among other factors, the uncertainties associated with temporal evolution of the system within a proposed scenario; the landscape changes arising from future human actions, climate and geological events and processes; the relationships between components of the disposal system and its immediate environment; the behaviour and characteristics of radionuclides within the system and their role in contributing to radiation exposure. In all cases, the different scenario-based models are typically used to determine the radiological significance of potential future discharges from waste disposal facilities. However, it is important to keep always in mind that in any specific case, the purpose of developing and/or applying a model may vary from a simple calculation (e.g. to support concept development) to detailed site-specific performance assessment in support of a disposal license application. The assumptions and modelling simplifications that are appropriate to one type of calculation may not be so easily justified in different circumstances. In order to develop the capability of modelling different long-term scenarios for a generic disposal site for low and intermediate level radioactive wastes, implementation of models of both the near-field/geosphere and biosphere were performed using general approaches for geosphere-biosphere interface, with sub-models for the whole system.

The Near-Field Transport Code Tullgarn and its Use in Performance Assessment

1992 ◽  
Vol 294 ◽  
Author(s):  
Patrik Sellin ◽  
Nils Kjellbert
Keyword(s):  
Performance Assessment ◽  
Near Field ◽  
Steel Corrosion ◽  
List Type ◽  
Spent Fuel ◽  
Radionuclide Migration ◽  
Transport Code ◽  
Damaged Zone ◽  
Chain Decay ◽  
Resistance Network Model

ABSTRACTThe near-field radionuclide migration code Tullgarn has been developed for performance assessment purposes. As a part of the PROPER-code package it has been successfully applied in the SKB 91 safety analysis.The features and processes included in the code are:- Radioactive chain decay- Different canister failure mechanisms (copper corrosion from sulphide attack, steel corrosion, internal overpressure and initially defective canisters) - Spent fuel dissolution. The model is based on the assumption that the dissolution rate is proportional to the α-dose rate- Transport calculations are done with a resistance-network model. Tullgarn calculates the stationary release of radionuclides from a defect in the canister through the buffer and out into a fracture in the rock or up to the damaged zone under the deposition tunnel.Tullgarn can be used as a stand-alone model for near-field release calculations or as a submodel in an integrated assessment. In the SKB 91 analysis, Tullgarn gave the source term to the far-field model.

Near-Field Chemical Composition of Porewaters in a Near-Surface Low-Level Radioactive Waste Vault

1996 ◽  
Vol 465 ◽  
Author(s):  
F. Caron ◽  
M. K. Haas ◽  
G. Manni ◽  
J. Torok
Keyword(s):  
Volatile Fatty Acids ◽  
Near Field ◽  
Inorganic Ions ◽  
Relative Distribution ◽  
Near Surface ◽  
Low Level ◽  
Major Species ◽  
Typical Composition ◽  
Waste Degradation

ABSTRACTA long-term waste degradation experiment has been performed with actual low-level radioactive wastes (LLRW) at the Chalk River Laboratories (CRL), to support the licensing and modelling efforts for near-surface disposal. The wastes consist of paper, mop heads, paper towels, used clothing, etc. The wastes were compacted into bales and sealed into separate steel containers, which were connected to leachate collection systems for sampling. The leachates collected had a composition typical of landfill leachates. The major inorganic ions were Na, Ca, Cl, and Fe, and the ionic strength was ∼0.05 M. The relative distribution of inorganic ions in the leachates was remarkably similar between bales. Volatile fatty acids (VFA) were the major species of dissolved organic carbon (DOC, total DOC up to 7000 mg/L). A typical composition of leachates is proposed, which can be used in geochemical and source term modelling.

SELECTION WORK TO IMPROVE PRODUCTIVE AND BREWING QUALITIES OF SPRING BARLEY

1970 ◽  
pp. 38-40
Author(s):  
О. V. Levakova ◽  
L. М. Eroshenko ◽  
А. N. Eroshenko
Keyword(s):  
Protein Content ◽  
Spring Barley ◽  
Humus Content ◽  
Stability Index ◽  
Field Studies ◽  
Climatic Conditions ◽  
Extract Content ◽  
Labile Phosphorus ◽  
Loam Soil

The article presents and analyzes data of competitive varietal testing of promising varieties and lines of spring barley for yield and brewing qualities. Field studies were conducted in 2014–2017 on dark gray forest heavy loam soil. Agrochemical parameters are total nitrogen – 0.24%, humus content in a layer of 0-40 cm (according to Tyurin) – 5.19%, hydrolysis nitrogen – 123.5 mg / kg, salt extract pH – 4.92 mg-eq / 100g; labile phosphorus - 34.6 mg / 100g, labile potassium – 20.0 mg / 100g. The forerunner is winter wheat. Meteorological conditions in the years of research differed from each other and from the average long-term value. Barley samples were assessed by the protein content in the grain (GOST 10846-91), extract content (GOST 12130-77), weight 1000 grains (GOST 10842-89). Ecological plasticity was determined by the method proposed by E.D. Nettevich, A.I. Morgunov and M.I. Maksimenko, stability index (Ľ) by A. A. Gryaznov, indicator of stability level (Puss) by E. D. Nettevich and A. I. Morgunov. The main measure for assessing quality indicators is protein content. Many other biochemical and technological features of grain depend on its level. The experimental data convincingly testify to the significant influence of the soil and climatic conditions on the yield and, especially, on the brewing qualities of barley in the conditions of the Central Region of the Nonchernozem Zone. According to the studied traits, new valuable varieties Nadezhny, Sir, Noble and selection lines 141 / 1-09 h 746, 23 / 1-10 h 784, distinguished by high adaptability and resistance to adverse environmental factors, have been identified.

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

Long-term performance of zeolite Na A-X blend as backfill material in near surface disposal vault

2009 ◽  
Vol 149 (1-3) ◽  
pp. 143-152 ◽  
Author(s):  
R.O. Abdel Rahman ◽  
H.A. Ibrahim ◽  
N.M. Abdel Monem
Keyword(s):  
Near Surface ◽  
Backfill Material ◽  
Long Term Performance ◽  
Term Performance

Modelling and Experimental Studies of Sorption in the Near Field of a Cementitious Repository

1989 ◽  
Vol 176 ◽  
Author(s):  
P.L. Brown ◽  
A. Haworth ◽  
R. McCrohon ◽  
S.M. Sharland ◽  
C.J. Tweed
Keyword(s):  
Near Field ◽  
Experimental Studies ◽  
Mass Action ◽  
Chemical Equilibria ◽  
Transport Code ◽  
Mass Action Model ◽  
Action Model ◽  
Modelling Studies ◽  
Simple Mass

ABSTRACTA joint experimental and modelling programme is reported, which aims to improve our understanding of sorption processes of radionuclides onto repository materials. Diffusion/sorption experiments of sorption onto cement are described, although results are limited at this stage. The modelling studies use the coupled chemical equilibria and transport code CHEQMATE to simulate some of these experiments. The chemical part of the model is based on a simple mass-action model of sorption. More detailed comparisons will continue when the experiments are terminated, and the samples are sectioned.

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