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
Thank you