The 12th International Conference on Environmental ... - Events

Abstracts Session 5-6
ically made of 70-85-percent bauxite, and are slowly worn away by the calcining process; bricks used to line the combustion chambers
wear away, as well, but at a slower rate. It has been recognized that the refractory materials contain slight amounts of naturally
occurring radioactive materials (NORM) from the uranium- and thorium-decay series. Similarly, low levels of NORM could be
present in the petcoke feed stock given the nature of its origin.
3) MEASUREMENT OF SOLID-LIQUID MIXTURES USING ELECTRICAL TOMOGRAPHY
MEASUREMENT TECHNIQUES - 16088
Gary Bolton, Industrial Tomography Systems (UK); StevenStanley, National Nuclear Labpratory (UK)
Electrical Impedance Tomography measurement techniques have been applied to a variety of solid-liquid processes in the laboratory
and on industrial plant. This paper reviews the advances in the measurement techniques to determine key process information
in solid-liquid systems such as concentration mapping, mixture homogeneity, interface detection and suspension velocity.
A number of applications to solid-liquid flow applications are presented. <strong>The</strong> use of the technology for improved design and
operation is highlighted, as are the opportunities for on-line sensing for flow measurement, fault detection and process control. A
recent development in high-speed electrical imaging has allowed velocity maps to be calculated for fast flowing suspensions (up
to 10 ms-1).
<strong>The</strong> methodology for determining mixture homogeneity in both pipeline flows and agitated tanks are summarised. Finally the
application of a linear ERT electrode array to identify interfaces during the settling of solid-liquid mixtures is presented.
SESSION 6 - LLW CHARACTERIZATION, TREATMENT & PACKAGING DEVELOPMENTS - PART 2 OF 2
1) INCREASING OPERATIONAL EFFICIENCY IN A RADIOACTIVE WASTE PROCESSING PLANT - 16100
Tom Turner, Stuart Watson, UKAEA (UK)
<strong>The</strong> solid waste plant at Harwell in Oxfordshire, contains a purpose built facility to input, assay, visually inspect and sort
remote handled intermediate level radioactive waste (RHILW). <strong>The</strong> facility includes a suite of remote handling cells, known as the
head-end cells (HEC), which waste must pass through in order to be repackaged. Some newly created waste from decommissioning
works on site passes through the cells, but the vast majority of waste for processing is historical waste, stored in below ground
tube stores. Existing containers are not suitable for long term storage, many are already badly corroded, so the waste must be efficiently
processed and repackaged in order to achieve passive safety.
<strong>The</strong> Harwell site is currently being decommissioned and the land is being restored. <strong>The</strong> site is being progressively delicensed,
and redeveloped as a business park, which can only be completed when all the nuclear liabilities have been removed. <strong>The</strong> recovery
and processing of old waste in the solid waste plant is a key project linked to delicensing of a section of the site. Increasing the
operational efficiency of the waste processing plant could shorten the time needed to clear the site and has the potential to save
money for the Nuclear Decommissioning Authority (NDA).
2) MANAGEMENT OF HISTORICAL RADIOACTIVE WASTE - 16267
Gheorghe Dograu, Felicia Dragolici, Laura Ionascu, GheorgheRotarescu, National Institute
of Reserch & Development for Physics and Nuclear Engineering-Horia Hulubei (Romania)
<strong>The</strong> development of the nuclear techniques in Romania and the commissioning of the WWR-S research reactor belonging to
the Institute of Physics and Nuclear Engineering -(NIPNE) demand to deal with the storage and disposal of radioactive waste. <strong>The</strong>
institute decided to store the radioactive waste inside a building that belonged to the Defense of Capital City System named Fortwhich
is located on the Magurele site. About 5000 packages were produced and transferred to the storage facility of radioactive
waste treatment plant after decommissioning of Fort building. In the mean time a repository was commissioned and the most part
of the waste has been disposed. <strong>The</strong>re still were remained about 800 packages which, in time, became corroded. A huge effort was
put in place in order to repack the waste for disposal. At the end of 2008, the whole amount of historical waste have been treated,
and disposed or stored.
<strong>The</strong> paper describes the management of historical radioactive waste from the storage facility of Radioactive Waste Treatment
Plant.
3) VOLUME REDUCTION OF RADIOACTIVE CONCRETE WASTES GENERATED
BY DISMANTLING NUCLEAR FACILITIES - 16165
Byung youn Min, Wang-Kyu Choi, Jung-Woo Park, Kune-Woo Lee, Korea Atomic Energy Research Institute, (Korea)
In Korea, the decontamination and decommissioning of the retired research reactors (KRR-1&2) and a uranium conversion
plant (UCP) at Korea Atomic Energy Research Institute (KAERI) has already been under way. Hundreds of tons of concrete wastes
are produced from these facilities. <strong>The</strong> recycle or the volume reduction of the contaminated concrete wastes through the application
of appropriate treatment technologies have the merit from the view point of the increase in resource recycling as well as the
decrease in the amount of wastes to be disposed resulting the reduction of disposal cost and the enhancement of disposal safety. It
is well known that most of the radionuclide is concentrated on the one of the concrete constituents, a porous hydrated cement matrix
and the radionuclide can be easily removed from the concrete wastes by separating cement matrix which can be done by heating to
weaken the adherence force between the cement matrix and the aggregates followed by mechanical crushing and milling processes.
<strong>The</strong>refore, KAERI has developed the volume reduction technology applicable to an activated heavy concrete waste generated
by dismantling KRR-2 and a uranium contaminated light concrete produced from a UCP, which can separate relatively clean aggregates
from the dismantled concrete wastes contaminated with α and β-γ emitters. <strong>The</strong> separation of radioactive constituents from
contaminated concrete waste carried out by heating and mechanical crushing and milling with the light and heavy concrete to establish
the volume reduction process for the concrete wastes generated by dismantling nuclear facilities. <strong>The</strong> volume reduction rate
could be obtained above 70% for the heavy weight concrete waste from the KRR-2 and above 80% for the light weight concrete
61