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Management of Radioactive Waste from NPP

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Management of Radioactive Waste from NPP Prof. Dr. A.M. El- Kamash Hot Lab.& Waste Management Center AEAE kamash20_at_yahoo.com Content Introduction Power reactor wastes ... – PowerPoint PPT presentation

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Title: Management of Radioactive Waste from NPP


1
Management of Radioactive Waste from NPP
  • Prof. Dr. A.M. El- Kamash
  • Hot Lab. Waste Management Center
  • AEAE
  • kamash20_at_yahoo.com

2
Content
  • Introduction
  • Power reactor wastes
  • Fuel cycle wastes
  • Treatment of Radioactive waste, and
  • Waste management practice in Egypt

3
Introduction
  • At the end of the 20th century, nuclear energy
    supplied about 16 of the world electricity needs
  • The growth of the nuclear industry in different
    countries has been the natural consequence of an
    increasing need for electrical power.

4
Introduction
  • The future prospects of nuclear power are related
    to the following issues
  • Public confidence, or at least tolerance,
    particularly on an accepted solution to the
    disposal of high level waste.
  • The competitiveness in terms of capital costs and
    construction periods.
  • Identification of appropriate linkages between
    nuclear power and environmental issues, such as
    global climate change, local air quality and
    regional rain acidification.
  • Lastly, the need for a global approach to some
    activities of nuclear power, such as nuclear
    waste management.
  • These issues are related to the countrys energy
    policy and international co-operation and
    therefore belong to the governmental domain of
    competence.

5
Introduction
  • Radioactive waste generated from NPP can be
    divided into
  • power reactor wastes, and
  • fuel cycle facility wastes,
  • Power reactors are responsible for the largest
    volume of LLW.
  • Fuel cycle plants, such as fuel enrichment plants
    and fuel fabrication plants, produce small
    volumes of LLW relative to power reactors.

6
Power Reactor Wastes
  • Component of NPP
  • Nuclear Power plant.exe

7
Power Reactor Wastes
  • The majority of power reactor wastes are
    classified as
  • Liquid radioactive wastes,
  • Wet solids (including slurries),
  • Dry active solid wastes (DAW),
  • Liquid organic wastes, and
  • Thermal waste.

8
Power Reactor Wastes
9
Power Reactor Wastes
  • 1) Liquid Radioactive Wastes
  • Liquid radioactive wastes are produced from
    recycled reactor core fluids, hydraulic fluid
    from equipment repairs, housekeeping activities,
    and laundering.
  • These wastes are treated to remove the maximum
    amount of radioactive contamination.
  • Treated liquids are then typically recycled or
    discharged to the environment under the control
    of the plant operating license and national
    regulations.

10
Power Reactor Wastes
  • 2) Wet solids
  • Radioactive wet solid wastes consist of solid
    wastes containing greater than 5 liquid. Most
    radioactive wet solid wastes are produced from
    cleaning aqueous processing systems at power
    reactors.
  • Spent Ion-Exchange Resins
  • Filter Sludge
  • Cartridge Filters

11
Power Reactor Wastes
  • 3) Dry active solid wastes
  • Anticontaminant clothing
  • Cloth (rags, mops, gloves)
  • Contaminated dirt
  • Contaminated tools and equipment, Filters
  • Glass
  • High density concrete block
  • Miscellaneous metal, Aerosol cans, Buckets,
    Crushed drums, Fittings, Pipes and Valves
  • Miscellaneous wood
  • Plastic
  • Bags, gloves, shoe covers, Sample bottles
  • Rubber,
  • Sweeping Compounds
  • Irradiated metal alloys
  • Flux wires, Flow channels, Fuel channels, In-core
    instrumentation, Poison channels, Shim rods.

12
Power Reactor Wastes
  • 4) Liquid organic wastes
  • liquid organic wastes includes pump oil,
    lubricating oils, organic resins, liquid
    scintillation counting solutions, and
    decontamination solutions containing organic
    chelating agents.
  • Liquid organic waste volumes are very small when
    compared to the total generated volume of LLW

13
Power Reactor Wastes
  • 5) Thermal waste
  • This waste is common both to conventional and
    nuclear plants.
  • The quantity of thermal waste proportional to the
    size of the plant.
  • In a NPP with a PWR operates at a thermal power
    of 1000 MW must dispose of approximately 2.4
    million Btu/s. If this quantity of heat were
    released into a river having a flow rate of 1000
    cubic ft/s, the entire river temperature would
    rise by 33 degrees Fahrenheit.

14
Fuel Cycle Wastes
  • Fuel cycle facility wastes include
  • Calcium fluoride generated from hydrogen fluoride
    gas scrubbers,
  • Filter sludge,
  • Contaminated equipment, and
  • Trash.

15
Fuel Cycle Wastes
16
Objective of RWM
  • To collect, handle, treat, condition, store,
    transport, and dispose RW in a manner that
    protects the human and the environment without
    imposing undue burden on future generation.

17
Principles of RWM
  • Establishing a national legal framework,
  • Control of radioactive waste generation,
  • Safety of facilities,
  • Waste generator pays,
  • Sound decision-making based on scientific
    information,
  • Risk analysis and optimization of resources,
  • International cooperation

18
Requirements of National RWM System
  • Organizational structure
  • Safety requirements and conditions
  • International recommendations, standards and
    agreements
  • National legislation
  • Cost and funding
  • Technical capability of personnel
  • Public involvement and political acceptance
  • Other non-technical factors
  • Geographic conditions
  • Opportunity for international co-operation
  • Physical infrastructure

19
Activities in RWM System
20
Treatment Technology
  • Treatment technologies of LLW and MLLW range from
    the very simple to extremely complex. These
    technologies could be divided into eleven broad
    categories as follows
  • ? Sizing ? Compaction
  • ? Filtration ? Decontamination
  • ? Evaporation ? Separation
  • ? Incineration ? Vitrification
  • ? Metal Recovery ? Immobilization/Stabilization
  • ? Physical/Chemical Treatments.

21
Treatment of RW
  • Treatment of aqueous wastes.
  • Treatment of solid wastes.

22
Characterization of Liquid Waste
  • Liquid wastes are generally characterized by
    their chemical, physical, radiological and their
    biological properties.  
  • Chemical properties toxicity, chemical
    composition of the liquid, pH value, oxygen
    demand, and Zeta potential.
  • Physical properties turbidity, density,
    viscosity, surface tension., conductivity,
    emulsifying ability
  • The radiological affect the choice of the
    treatment process and and the radiological impact
    to operators and the surrounding environment.

23
Selection of Treatment System
  • Selection of a liquid waste treatment system
    involves a set of decisions related to the
    following factors. 
  • Characterization of arising waste,
  • Discharge requirements for decontaminated
    liquors,
  • Available technologies and their costs,
  • Conditioning of the concentrates, and
  • Storage and disposal of conditioned concentrates

24
Treatment Processes
  • Selection of a process for liquid wastes
    treatment depends on the radiological and
    physico-chemical properties and the quantity of
    arising waste.
  •  The processes commonly used for treatment of
    liquid radioactive wastes fall generally into
    three main categories 
  • Chemical precipitation,
  • Ion exchange, and
  • Evaporation.

25
Ion Exchange
  • Ion exchangers are insoluble solid materials
    which carry exchangeable ions. These ions can be
    exchanged by a stoichiometrically equivalent
    amount of other ions of the same sign when the
    ion exchanger is in contact with an electrolyte
    solution.
  • Ion exchangers are generally classified according
    to their exchange function
  • Cation Exchangers,
  • Anion Exchangers
  • Amphoteric Ion Exchangers 

26
Advantages of Ion Exchange
  • Treatment procedures are based on well proven,
    conventional process and equipment,
  • Suitable for ionic impurities,
  • High quality effluents are possible,
  • Adequate for separation of several radionuclides
  • High decontamination factor achievable giving
    low volumes of solid waste which can be readily
    conditioned for disposal,
  • Suitable for separation of colloids, and
  • Suitable for continuous and automatic operation.

27
Disadvantages of Ion Exchange
  • Salt content and suspended solids must be low,
  • Non electrolytes are not exchanged, colloids, and
    contaminants can cause difficulties,
  • Some exchangers are pH-sensitive,
  • Regeneration give rise to secondary wastes,
  • Some exchangers have low radiation tolerance,
    especially organic materials
  • Some exchangers (e.g. organic) are expensive,
  • Some exchangers have limited stability to heat

28
Evaporation
  • Types of Evaporators
  • Dot kettle. natural forced circulation, vaiour
    cothpression and wiped-filin evaporators.
  • Evaporators which can operate in the presence of
    solids appear to be the most suitable for the
    treatment of bearing waste streams, since
    actinide hydrolysis products are mainly
    associated with suspended particulates and
    colloidal materials in feeds that are weakly
    acidic or neutral.

29
Advantages of Evaporation
  • Large volume reduction for a range of effluents,
  • Good decontamination from non-volatile
    radionuclides,
  • Complete removal of all active and inactive salts
    from waste effluent allowing reuse of condensates
    and avoiding the problems caused by the
    build-up of inactive salts.
  • Unaffected by the presence of complex agents in
    waste effluents, unlike many of the alternative
    treatment processes

30
Limitations of Evaporation
  • Unsuitable for waste effluents containing large
    salt concentrations,  
  • Expensive compared to other treatment processes
    due to the high energy needs.  
  • The problems caused by corrosion, scaling and
    foam formation may prevent the successful
    application,
  •  The presence of some organics can result in
    explosions on evaporation and appropriate
    pretreatment is required, such as steam
    stripping.

31
Discharge Requirements for Decontaminated Liquors
  • Restrictions or limits on release of the
    decontaminated liquors should be carefully
    considered.   Determination of these limits is
    done differently in various countries but does in
    all cases, require extensive analyses by both the
    waste producer and regulating authority to arrive
    at an agreement that the releases are acceptable.

32
Conditioning of Sludge, Concentrates and Ion
Exchangers
  • Two methods have been used cementation and
    bitumization.
  • For each matrix material, several techniques
    could be used in view of how the wastes are
    mixed with the matrix material.
  • Normally, immobilization is carried out in fixed
    installations at the site of waste generation,
    but also mobile systems have been developed for
    some applications

33
The management strategy for solid waste of small
nuclear research centers in developing countries.
34
Main features of the solid waste treatment
processes.
35
Treatment Technology
  • Compaction
  • A well proven volume reduction technology used to
    reduce the total volume of waste. This is
    accomplished by applying high pressures to the
    waste, which reduces void space.
  • Compactor systems consist of a press, using
    horizontal or vertical rams to apply pressure to
    the waste in a drum or box-type container. Volume
    reduction achieved during compaction is a
    function of
  • Void space in the waste,
  • The force applied by the press, and
  • The bulk density of the material.

36
Treatment Technology
  • Compaction
  • Advantages of compaction include
  • Compaction is a proven process used throughout
    the world in the nuclear industry,
  • Compaction systems are simple, and tend to be
    reliable and trouble free,
  • Waste compaction is relatively inexpensive, and
  • The process is simple to operate.

37
Treatment Technology
  • Compaction
  • Disadvantages of compaction include
  • Most commercial compactor systems are not
    available with adequate exhaust equipment and
    must be modified,
  • Compactors cannot reduce the hazard of the
    incoming waste, and are therefore not appropriate
    for treating waste streams with hazardous
    constituents,
  • Compaction is not recommended for wastes
    containing free liquids, or with wastes
    containing explosives, and
  • Compaction should not be used on dense or bulky
    items where minimum volume reduction would be
    achieved.

38
An in-drum compactor
39
IMMOBILIZATION MATERIALS AND PROCESSES
40
Benefits of Solidification
? Prevent dispersion of fines and liquids
during handling
? Minimize releases of radionuclides and
hazardous constituents after disposal
? Reduce potential exposure to intruders,
long term solution
41
Desirable properties of a solidification agent
? Availability
? Low cost
? Volumetric efficiency
? Simplicity of use
? Good waste form properties
42
Important properties of solidified waste forms
? Low leachability
? High chemical stability
? High compressive strength
? High radiation resistance
? High resistance to biodegradation
? High thermal stability
? Low solubility
43
Solidification agents currently in use
? Cement, with and without additives
? Blended Cements (Fly ash, slags, etc.)
? Bitumen


? Glass or ceramics
?Polymers

44
Pictorial flow sheet of liquid waste processing
45
Conditioning of compatible radioactive solid
wastes by in-drum compaction
46
Conditioning of non-compatible radio- active
solid waste
47
Advantages and disadvantages of cement
Advantages
Disadvantages
? Technology and materials are well known
and available
? Some wastes affect setting
? Compatible with many wastes
? Swelling and cracking may occur
? Volume increase and high density for
shipping and disposal
? Low cost
? Good impact and compressive
strength
48
STORAGE
49
Typical stacking of waste drums
50
OVERVIEW ON THE TREATMENT OF RADIOACTIVE WASTE IN
EGYPT
51
  • The liquid radioactive waste Treatment Facility
  • The facility treats
  • - 10 m3 per day of LLW
  • 2 m3 per day of ILW
  • Average activity
  • 37- 3700 KBq/L

52
Material flow diagram of the liquid radioactive
treatment facility at Inshas Site
53
1- Low level waste processing
Reception and averaging
Coagulation
Settling
Clarifying and
Demineralization by ion exchange
54
2- Intermediate level waste processing
Reception, averaging and pH-conditions
Evaporation
Secondary steam condensation
Concentrate collection and
Immobilization by cementation
55
  • IN-LINE CEMENTATION UNIT
  • At Inshas Site
  • Put into operation for one to two shifts per
  • week
  • Treats about 3 m3 of solid wastes
  • (concentrates) per shift
  • Volume of cement in the hopper is 8 m3

56
Simplified flow diagram for the in-drum
cementation unit
57
SOME PHOTOS OF THE LIQUID RADIOACTIVE TREATMENT
FACILITY AT INSHAS SITE
58
CONTAINER OF RADIOACTIVE WASTES (2.0 m3)
59
ION EXCHANGE COLUMNS
60
BIOLER FOR ILW
61
LINE FOR EVAPORATOR CONCENTRATES AND SLUDGES TO
THE CEMENTATION PLANT
62
OVERVIEW OF CEMENTATION PLANT
63
CEMENTATION PACKAGES
64
CUBIC CEMENT CONTAINERS (1.0 m3)
65
One of the FOUR Disposal Trenches
66
The first interim Store
67
The New stores
68
One of The two New Stores
69
The new Disposal Trenches with its Receiving Hall
70
The Drainage Well for the Four Trenches
71
The Entrance of the Hunger
72
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