use of gamma radiation for sterilisation and other ......alternatives to what? the “incumbent...

Use of gamma radiation for

sterilisation and other industrial

applications

Dr Steve Sugden

Panel on Gamma and Electron Irradiation

Outline of presentation


• Introduction and background

• Where it all started?

• Why we do it

• How we do it

• Gamma irradiation – strengths and weaknesses

• Current usage and competitor technologies

• Trends and future challenges

Radiation processing with gamma


Steve Sugden

• 25 years at the Harwell Nuclear Research Centre, UK

• Commercialisation of radiation processing technologies

• GM AEA Technology EBIS / Isotron accelerator site

• Radiation processing consultant

Panel on Gamma and Electron Irradiation

• Established in 1963 – “body of experts”

• International membership

• Guidance on radiation processing best practice and standard

development/implementation

Introduction


First industrial cobalt-60 irradiator

Established at Wantage, UK in 1960

- the Package Irradiation Plant (PIP)

Where it all started?


The need for product irradiation

• Sterility is requirement for many healthcare products

• Food can be treated to eliminate pathogens or pests

• Polymers can be ‘cross-linked’ to improve mechanical

properties

Need penetrating radiation to treat dense, solid products

and to allow treatment inside final packaging

Why do we do it?


Cobalt-60 suitability

• Highly penetrating gamma radiation

• Isotope is easy to make (reactor)

• 5.3 year half-life

• Not soluble in water

• Relatively inexpensive

How do we do it?


Cobalt irradiation sources (courtesy of Nordion)

How do we do it?


Cobalt irradiation plant (courtesy of Nordion)

How do we do it?


Strengths

• Penetration of radiation

• Good dose uniformity

• Reliability/simplicity of

process/plant

• Scalable (just add cobalt)

• Good safety record

Gamma – strengths/weaknesses

Weaknesses

• Cannot turn off

• Batch process (scheduling)

• Cobalt monopoly/cost

• Security issues

• Only small ‘economies of

scale’


Current status

• Primary use sterilisation of medical devices ($300bn market*)

• Global sterilisation market $4.7bn*

• 41% sterilised using gamma, 4.5% by electron beam*

• Annual growth rate of 9%*

• Over 200 large-scale gamma irradiators worldwide, with 400

million Curies of cobalt-60*

• Of these, around 50 facilities containing 200 million Curies of

cobalt-60 are in the United States

• Common radiation sterilisation quality standard ISO 11137

* source: iia/GIPA

Current usage and competition


• Increasing cost of cobalt-60 (limited supply)

• Emergence of X-ray as economic competitor

• Security and sustainability concerns (particularly from US)

Gamma–trends & future challenges

Alternative technologies for radiation processing

Presented at the IAEA in Vienna Austria

19 September 2019

David Brown

Alternatives to what?

▪ The “incumbent technologies” for sterilization applications and food decontamination

are Cobalt-60 and Ethylene Oxide gas.

▪ The “incumbent technologies” for phytosanitary applications are Cobalt-60, Ethylene

Oxide, heat, cold, and Methyl Bromide gas.

▪ In Darwinian evolution, the key to survival is adaptation through diversity and natural

selection.

▪ The same principle can be applied to the irradiation market.

▪ In many cases these technologies can substitute for each other….diversity.

▪ In some cases e-beam and x-ray can be substitutes/alternatives for Cobalt-60.

Substitution matrix…. Radiation will probably grow

Radiation Ethylene Oxide

Methyl Bromide Heat or Cold

Sterilization or Decontamination

Technologies

PHYTO

STERILIZATION &

FOOD SAFETY

P

H

Y

T

O

P

H

Y

T

O

Radiation technology selection

Options?Thickness?Radiation

Compatible?

Gamma

X-Ray

E-beam

Thick

Gamma

Availability?

Licensing?

Transportation?

X-ray

Electricity supply?

Technological complexity?

Thin E-beamFlexibility?

Product handling?

My topic….▪ Electron accelerators for the radiation processing market of the future.

▪ What will the radiation processing market look like? ….It will grow

▪ There is pressure to reduce the emissions levels and the residuals in EtO processes

▪ Methyl Bromide will be phased out for phytosanitary applications soon

▪ What role will accelerators play in the radiation processing market?

▪ Perturbations in the supply of Cobalt 60 have caused gamma users to look at other options

▪ The economic cases for x-ray and gamma are quite similar

▪ The economic case for e-beam vs x-ray and gamma can be very attractive

▪ X-ray and e-beam technologies are becoming more reliable and more available than in the

past

▪ Electricity supply is not challenging for e-beam applications but can be challenging for x-ray

applications in some locations

Accelerators for substitution of radio-isotopes

Medium power

▪ Electron beam sterilization

▪ Food safety

▪ Phytosanitary

▪ NDT

▪ Small scale x-ray

▪ Research

▪ Pilot-scale

Low power

▪ Cs-137 experimental irradiators

▪ Gammacell 220 replacement

▪ Cancer therapy applications

▪ Blood irradiators

▪ NDT applications

▪ Security inspection

High power

▪ X-ray for contract irradiation

▪ Large gamma plant replacement

▪ Food applications

▪ Waste water

▪ Materials modification

▪ Environmental remediation

Low power substitution

▪ 1MeV, 5-10kW with x-ray converter (Research)

▪ 2MeV, 5-10kW with x-ray converter (Cs-137 replacements)

▪ 4MeV, 5-10kW with x-ray converter (Co-60 replacement)

▪ 5 – 10MeV, 5-20kW adjustable energy e-beam and x-ray machines (Research and

pilot-scale production)

▪ Note: Machines with higher than 2MeV electron energy can be very useful in e-beam

mode as well (if they have a removable x-ray converter… technical challenge)

Medium power substitution

▪ 1MeV, 20-50kW with x-ray converter (Research, high value sterilization)



▪ 5 – 7MeV, 20-80kW adjustable energy e-beam and x-ray machines (Commercial scale

phytosanitary, research applications, and pilot-scale sterilization/materials)

▪ 10MeV, 30-100kW e-beam mode can replace between 2 and 10MCi of Co-60 if the

products are compatible.

▪ Note: Machines with higher than 2MeV electron energy can be very useful in e-beam

mode for x-linking (if they have a removable x-ray converter… technical challenge)

High power substitution

▪ 5 – 7.5MeV, 200-600kW adjustable energy x-ray machines (Commercial gamma

replacement)

▪ Note: The rule of thumb for estimating the equivalence between x-ray and gamma is:

▪ 120-140kW per MCi for 5MeV incident electron energy

▪ 85-100kW per MCi for 7.5MeV incident electron energy

Psychology of substitution….

Mindset 1: Calm and Rational

▪ There have never been any security problems

with Cobalt

▪ Supply perturbations happen suddenly but Cobalt

is still in the facilities and decay is slow

▪ We can add e-beam to existing gamma plants

and transfer the easy products to e-beam

▪ Add e-beam capacity to approximate the decay of

Cobalt and the market growth

▪ Cobalt and e-beam complement each other nicely

▪ Cobalt has very low carbon footprint

▪ E-beam is electrically efficient and has a small

carbon footprint

Mindset 2: Clear and Present Danger

▪ Supply perturbations happen suddenly and

satisfying the market demands is threatened

▪ Build x-ray plants and begin to transfer the

products to x-ray

▪ Move everything from gamma to x-ray on a short

time-line

▪ Build e-beam capacity to provide low carbon

footprint option

▪ Select locations with excellent quality electricity

supply and low price

What is happening today▪ New e-beam capacity is being built around the world

▪ New X-ray capacity is being built around the world

▪ Multiple sites will provide backup capacity across the network to address downtime concerns

▪ More opportunities for product testing at sites with e-beam and x-ray at the same site

▪ Investments in new technologies are being made in order to meet current and future demand for equipment

▪ Risk is mitigated because high power solutions already exist or are built on existing platforms

▪ Industry “ramp-up” requirement due to lack of cobalt availability is matched by accelerator manufacturers

▪ Higher electrical efficiency

▪ Higher beam power

Adding machine capacity to match Cobalt decay…Leverage existing infrastructure where

possible

▪ Ramp up machine source capacity to match

Cobalt decay and new market growth

Leverage all 3 modalities as required

▪ Use e-beam for efficiency

▪ Leave legacy products in gamma for as

long as necessary

▪ Use x-ray for products that can’t be treated

in e-beam due to penetration or DUR

Compatibility needs to be established

▪ Gamma products are x-ray compatible

▪ E-beam may have differences in material

properties, charge deposition, and rate of

heating/cooling

What are we doing as an industry?

▪ NNSA-supported collaborations like Team Nablo (IBA and Mevex both members)

▪ New guidance being written on transitions between radiation modalities through AAMI WG2

▪ FDA has challenged the industry to drive the development of alternatives to EO and gamma

▪ Follow up from Kilmer collaboration on Modality Changes and Process Optimization

▪ Support for publications

▪ Identify training gaps and opportunities

▪ Provide support for FDA tools

Technical challenges for machine-sources….

▪ Reliability of the equipment (Cobalt always works)

▪ Equipment manufacturers must continue to take accelerators out of the laboratories and into the factories

▪ Continue to improve remote monitoring and predictive maintenance

▪ Electrical efficiency and cost of electrical power (Cobalt does not consume much electricity)

▪ Equipment manufactures must innovate to find better electrical efficiencies balanced against cost and

complexity

▪ Efficiency improvements from other industries must be adopted for accelerator technology

▪ Environmental impact of electricity use (Cobalt has nearly zero carbon footprint)

▪ Equipment manufacturers must think about how to make their machines compatible with how power from

renewable sources is suppled to reduce carbon footprint

▪ Cost of consumable parts and maintenance for the accelerator must be reduced

Industrial machine-source technologiesName of machine Type of machine Maturity /

Commercialization

Energy capability Beam power

Rhodotron RF with re-circulating

beam

Mature 3 to 10MeV

Higher energies (up to

40MeV) are being

explored

10kW to 560kW

Linac RF with straight-through

beam

Mature 3 to 35MeV

(Higher is no problem)

2kW to 100kW

Dynamitron RF power supply to DC

terminal with straight-

through beam

Mature 0.8 to 5MeV

(5MeV is the limit)

10kW to 200kW

SRF Linac Super conducting Linac Mature in research

centers.

Not deployed for

industrial

1 to 35MeV

(Higher is no problem)

Unknown

Betatron RF with recirculating

beam

Mature for NDT

applications

1 to 20MeV Less than 1kW

The language of machine-sources

General strategies that lead to higher accelerator efficiencies:

▪ “High beam loading”

▪ Beam loading is the ratio of the power put into the electron beam divided by the power

used to generate the accelerating field

▪ When average RF power is limited, pulsing is a way to produce high powers for a

short time which allows a higher proportion of the power to be transferred to the beam.

▪ This principle applies to room temperature linacs and re-circulating machines

▪ Super-conducting machines do not use power to produce fields but the cryo-system

power could be used as an analog for field power.



▪ “High efficiency RF sources”

▪ RF (radio-frequency) sources are used produce the accelerating voltage in industrial

accelerators

▪ If the RF source is not efficient then the accelerator will never be efficient

▪ Conversely, a very efficient RF source could be used in a poorly “loaded” accelerator

and the overall system would be inefficient.

▪ Typical RF sources used in accelerators are:

▪ Tetrode (60 - 70% efficient)

▪ Klystron (40 – 50% efficient)

▪ Magnetron (80 – 90% efficient)



▪ “Efficiency as a function of beam power”

▪ Pulsing is a way to (roughly) maintain the electrical efficiency of a machine while

operating it below its maximum design power

▪ Pulsing can create challenges in maintaining dose uniformity at low doses due to

spot/line overlapping requirements

▪ Pulsing can create challenges for validating process interruption and process re-starts

▪ CW machines tend to have very poor efficiencies when operated at low beam power

Where can I learn more about e-beam and x-ray?▪ IAEA Consultancy Meeting reports

▪ AAMI membership

▪ ASTM Dosimetry workshop, June 21-25 2020, Prague, CZ

▪ Texas A&M eBeam Workshop, April 2020, College Station, TX

▪ Other dosimetry resources (RISO, GEX)

▪ Riso High Dose Reference Laboratory Course – Validation and Process Control for EB

Sterilization, September 2019

▪ STERIS and Sterigenics Seminars

▪ Conferences like IMRP (International Meeting on Radiation Processing), 2021 Bangkok, Thailand

▪ iia Membership / website

▪ 6th Annual PPQ Upon-Arrival Phytosanitary Irradiation Stakeholder Meeting at the 2018 Annual

International Research Conference on Methyl Bromide Alternatives and Emissions Reductions

Conclusions▪ The market has spoken: e-beam and x-ray capacity is growing faster than other

technologies

▪ The economics are similar between all technologies so the availability of capacity will

be the major deciding factor

▪ The trend towards radiation processing being dominated by accelerator-based

technology has begun….

Things that seemed adequate…. …Are replaced by things that seemed impossible.

Sterilization with Gamma, X-Ray and E-

beam: users’ perspective

Short Company History1996 Start of operation with one linear accelerator

1998 Mediscan becomes member of Greiner

1999 Takeover of the Cobalt 60 plant from the Austrian Research Center Seibersdorf

2000 Commissioning of the first Rhodotron accelerator

2009 Commissioning of a second Rhodotron accelerator (with X-Ray function)

2015 Start of operation of the new Rhodotron TT300 Dual Line accelerator for E-beam and X-Ray treatment

Greiner Bio-One International GmbH

(Kremsmünster)

Greiner Bio-One GmbHAustria

(Kremsmünster)Medical Devices and IVDs

Greiner Bio-One GmbH Germany

(Frickenhausen)Laboratory Material

Mediscan

GmbH & CoKG(Kremsmünster)

Intercompany approx. 40%Third party approx. 60%

• Contract Irradiation

• Consulting & Project Support

• Training for Customers and Notified Body Auditors

Core Competence

Technologyo E-Beam / X-Ray:

• Two Rhodotron TT100 electron accelerators with an electron energy of 10MeV, one TT100 equipped with an additional 6,6MeV X-Ray line

• One Rhodotron TT300 “dual line” electron accelerator for E-beam treatment with an electron energy of 10MeV and X-Ray sterilization with a maximum energy of 7MeV

Technologyo E-Beam / X-Ray

Technology

o Gamma (60Co): • Gammatron 1500 60Co irradiator with a maximum

capacity of 1.5MCi

• Treatment of one or more shipper boxes in irradiation totes

Capacity

E-Beam (Kremsmünster)• Continuous Shift (Sun 22h – Fri 22h)

• Saturday optional

• >800 Standard Pallets / day (e-beam)

Gamma (Seibersdorf)• Continuous Shift (Mon-Sun; 0-24h)

• > 55 Standard Pallets / day

Treated Products (Mediscan)• Medical Devices E/X/G

• In Vitro Diagnostics E/X/G

• Laboratory material E/X/G

• Pharmaceutical Packaging Materials G/X

• Packaging materials for food and beverages E

• Moulded Parts E

• Plastic Granulate G

• Semi Conductors and Thyristors E

• Medicinal Products, APIs and excipients G

• Human tissue allografts G

• Books and records G

• Animal food and tidbits E

Choice of Technology (traditional)

o Density of the product

• Higher density (> 9g/cm²) Gamma or X-Ray

• Lower density (< 9g/cm²) Electron Beam


o Dose requirements (tolerances)

• Narrow dose range (< 30% overdose ratio)Gamma tote irradiator or X-Ray pallet layer irradiation

• Medium dose range (50-120% overdose ratio) Gamma pallet irradiator or X-Ray pallet irradiator

• Wide dose range (30 – 200% overdose ratio)Electron Beam


o Throughput (speed and volume)

• Slow throughput Gamma

• Medium speed X-Ray

• High throughput Electron Beam

Decision for Electron Beam Technology (modern)

Prerequisite: knowledge about the specific requirements and regulations for each product. The product is presented to the beam in optimized packaging systems and/or single layers

o Density of the product

• Higher density (> 9g/cm²)

E.g. implants

o Dose requirements (tolerances)

• Narrow dose range (10 - 20% overdose ratio)

E.g. biologics

Advantages Gamma

o Simple technology

o Very reliable equipment

o High permeation

o Widely accepted

o Good dose homogeneity

Disadvantages

o Cobalt supply

o Loss of capacity over the year

o No “turning off”

o Safety concerns due to high amount of radioactive material

o Disposing of Cobalt sources after use

o Limited flexibility for dose and load

o No individual fine adjustment

o Lower dose rate

Advantages E-beam

o No loss due to “unused” decay

o High throughput

o High dose rate

o High level of automation possible

o Building up of additional capacity

o No radioactive material

o High flexibility regarding dose and load

o Very accurate fine adjustment possible

o No influence from irradiator load

Disadvantages

o Low Permeation

o Complex technology

o Wider dose range

o Intricate dose characteristics inside the product

o Temperature increase at high doses

o Electric charging / discharging

Advantages X-Ray

o Higher dose rate than Gamma

o No Temperature issue

o Good dose homogeneity

o High flexibility regarding dose and load

Disadvantages

o Loss of dose due to conversion of electrons to photons

o Need for high power accelerators

o Lower throughput compared to E-beam

o Low acceptance in pharmaceutical industry

Trends

o Demand for irradiation capacity is increasing in many industrial areas

o Gamma

• Due to shortage in Cobalt supply the need for alternative technologies increases

o E-Beam

• Demand in E-beam is increasing. New products are developed for E-beam treatment

o X-Ray

• X-Ray will gain importance for products which cannot be treated with E-beam

Thank you for your attention

IAEA activities to support gamma, e-beam, and X ray irradiation for industrial applications

Valeriia Starovoitova

Radioisotope Products and Radiation Technology Section

Department of Nuclear Sciences and Applications

International Atomic Energy Agency

September 2019

• Set up in 1957 to promote safe, secure and peaceful nuclear technologies

• Currently includes 170 (May 2018) Member States

• 2300 professional and support staff

• Headquarters in Vienna• Two scientific laboratories

and research centres• Liaison offices in New York

and Geneva

International Atomic Energy Agency

2

The “Three Pillars” of the IAEA

Safeguards

&

Verification

Safety

&

Security

Science

&

Technology

3

IAEA Organization – RPRT Section

Office of the Director General

Department of Management

Department of Nuclear Energy

Department of Nuclear Science and

Applications

Division of Physical and

Chemical Sciences

Radioisotope Products and

Radiation Technology Section

Department of Technical

Cooperation

Department of Nuclear Safety and Security

Department of Safeguards

4

5

Coordinated Research Projects (R&D) 15

Technical Cooperation Projects (implementation) 160

Regular program activities

Networks &

coalitions

Participation in

complimentary

international

activities

Meetings /

Conferences

Missions

Publications

General

Conference

side-events

and Scientific

Forum

Collaborating

Centres

RPRT Projects

RPRT Activities

❖ Research and Development

❖ Implementation of Technologies

❖ Education / Training / Qualification

Areas:

• Production of Medical Radioisotopes and Radiopharmaceuticals

• Non-Destructive Testing/Radiotracers in Industry/Nucleonic Gauges

• Radiation Technologies for Various Applications

6

RTRP Projects: Polymer Modification [1]

• INSTRUCTIVE SURFACES AND SCAFFOLDS FOR TISSUE ENGINEERING USING RADIATION TECHNOLOGY

To engineer instructive scaffolds and surfaces using radiation technology to create tissue grafts and decrease the need for human donors.

• X-RAY VS GAMMA IRRADIATION EFFECTS ON POLYMERSThe objective of this project is to identify and resolve issues of irradiation effects (gamma, X ray, and e-beam) on polymers common for medical devices.

7

RTRP Projects: Polymer Modification [2]

• DEVELOPMENT OF RADIATION-GRAFTED MEMBRANES FOR CLEANER AND SUSTAINABLE ENERGY

The objective of this project is to develop radiation-grafted membranes, which will be used for electrochemical devices, membranes separating CO2 from natural or renewal gas, and catalysts for biodiesel production.

• RECYCLING OF POLYMER WASTES BY RADIATION

The objective of this project is to engineer feasible innovative applications for solving the environmental problem introduced by large amounts of plastic wastes.

8

RTRP Projects: Nanotechnology• NANOSIZED DELIVERY SYSTEMS FOR

RADIOPHARMACEUTICALS

The aim of this project is to provide significant improvement in the delivery of therapeutic radiopharmaceuticals through the use of nano-constructs built from radiation-synthesized polymers.

• ENHANCING THE BENEFICIAL EFFECTS OFRADIATION PROCESSING IN NANOTECHNOLOGYThe objective of this project is to exploit theinnovative methodologies and technologies tofabricate high performance and High Value-added Nano-products for the applications inElectronics, Environment, Energy, & Advancedmaterials.

9

RTRP Projects: Environmental Engineering

• RADIATION INACTIVATION OF BIO-HAZARDS USING HIGH POWERED ELECTRON BEAM ACCELERATORS

The objective of this project is to enhance and strengthen use of electron beam accelerators for treatment of biohazards of concern.

• RECENT ADVANCES IN THE TREATMENT OF EMERGING ORGANIC POLLUTANTS

The objective of this project is to develop new methods for radiation treatment of emerging organic pollutants (antibiotics, endocrine-disruptive compounds, etc).

10

RTRP Projects: Radiation Facilities [1]

• ECONOMICAL FEASIBILITY OF TRANSITIONING FROM GAMMA STERILIZATION TO ACCELERATOR-BASED STERILIZATION

To discuss construction and operational costs of sterilization facilities, which greatly depend on type of the facility, products they sterilize, and country

• LOW ENERGY E-BEAM FACILITIES

The purpose of the event is to share information on the development of radiation generators (low energy electron beam and X ray) to replace radioactive isotope sources, and to reach consensus on potential areas of application for future development.

11

RTRP Projects: Radiation Facilities [2]

• Updating old directories: 2004 directory of gamma facilities and 2008 directory of e-beam facilities

• Information from >200 facilities worldwide is already collected and continues to arrive.

12

RTRP Projects: Cultural Heritage

• DEVELOPING RADIATION TREATMENT METHODOLOGIES AND NEW RESIN FORMULATIONS FOR CONSOLIDATION AND PRESERVATION OF ARCHIVED MATERIALS AND CULTURAL HERITAGE ARTEFACTS

The purpose of this project is to evaluate the effects of irradiation on the functional properties of artefacts’ materials and investigate post-irradiation effects and appropriate irradiation procedures for

wider use of the technique.

13

RTRP Projects: e-Learning

• E-LEARNING MODULE DEVELOPMENT FOR MATERIAL MODIFICATION

• E-LEARNING MODULE DEVELOPMENT FOR CULTURAL HERITAGE PRESERVATION AND CONSOLIDATION

14

Other RTRP Activities [1]World Nuclear University (WNU) training programs:

• School on Radiation Technologies - a two-week program for young professionals

• Nuclear Olympiad - an international challenge for undergraduate and graduate students on effective public communication on nuclear science and technology

15

Other RTRP Activities [2]

16

AccApp’20: 14th International Conference on Nuclear Applications of Accelerators

April 5-9, 2020, Vienna

Jointly organized by ANS and IAEA and focused on applications of accelerators

Other RTRP Activities [3]

17

ICARST-2021, 2nd International Conference on Applications of Radiation Science and Technology

April 19-23, 2021, Vienna

Organized by IAEA and focused on radiation science and technology

THANK YOU FOR YOUR

ATTENTION!

use of gamma radiation for sterilisation and other ......alternatives to what? the “incumbent...

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