Technology Supplier Perspective
Radiation Processing of Horticultural Products
Joseph Borsa, Ph.D.
MDS Nordion
Presented at USDA Irradiation Workshop for Horticulturalists
Sacramento, California
November 30, 2004
In this presentation……A little bit about MDS Nordion….who we are Radiation processing of horticultural products What’s driving it forward Some key technical considerations
Focus on some of our products suitable for this purposeEconomic basics of irradiation / overviewBarriers / impediments to implementation MDSN initiatives to help overcome them
This will be a broadbrush picture…..presenting irradiation in the context of an enabling technology, that is an integral part of the “agricultural export infrastructure”
MDS Nordion….
…..the premier technology supplier serving the radiation processing industry
MDS Nordion….A little closer lookTechnology company based on nuclear science “Science Advancing Health” tagline says it allThree main areas of business Industrial irradiation Therapy systems Radiopharmaceuticals
Over 40 years in businessCurrently about 1000 employees worldwideOur core products: hardware / know-how / supplies / serviceHundreds of installed cobalt-based therapy systems around worldMajor supplier of radiopharmaceuticals for nuclear medicine
applications Over 120 cobalt-60 powered industrial irradiation facilities in
service around the world
Our interest in food irradiation
Goes back for decadesNational and international scenesSupported and promoted it in a variety of ways “Missionary” type of education activities promoting the
technology Prepare and file petitions for regulatory clearance Support R&D Developed state-of-the-art technology systems to meet the
stringent processing demands for treating food
Technology supplier to the first irradiator in the USA dedicated to food irradiation (former Vindicator)
Radiation processing of horticultural products……
Why irradiate horticultural products?
Disinfestation for quarantine security purposes This is the main driver today
Sprout inhibition Various tubers /potatoes/onions/garlic/yams/? A secondary driver currently / significant need in this area
Enhancement of food safety and extension of shelf-life Fruits and vegetables linked to outbreaks of food-borne illness Growing interest in using irradiation to deal with this problem
It’s effective and it leaves the products raw and fresh Not yet a major driver, but this could change Dose for this purpose is roughly 10-fold higher than for the other
two applications
Radiation disinfestation “adds value”
It helps convert agricultural surpluses into exportable products that can be sold in international markets, providing an economic boost for farming communities and agricultural economies
This represents major “added value”
Why radiation disinfestation? Fast and convenient Treatment is fast / product is ready to use immediately after
treatment No ‘aeration’ holding time required Not affected by temperature or humidity No water dipping which can spread microbial contamination Can be done with product already packed in shipping cases No hazardous chemicals
Effective For a variety of pests For a variety of product types Closest we’re likely to get to a “universal” disinfestation technology
Ideal disinfestation technology for central system integrated into the agricultural export infrastructure
Locate at point of egress from a production region
Some key technical considerations…..
Source option considerations Choice of photons (gamma rays, x-rays) or particulate radiation (electrons)
Basically “radiation is radiation” in terms of effects.They all do the job, once the dose is delivered
Each has its advantages and limitations
They have different penetration characteristics
Photons allow you to process even large objects
Individual fruits or vegetables Packages and stacks of packages
Agricultural products come in different sizes and shapes….
All types need to be treated
The radiation must reach all parts of all products
Photons can treat all sizes of individual products, i.e. anything from cherries to watermelons
To illustrate…….
Comparison of Dose Distributions
Thickness = 3.7 inches
10 Mev electrons 1 sided
10 Mev electrons 2 sided
Photons
Pretend this is a papaya or mango or grapefruit or ?
More dose distribution comparisons
Electrons1 sided
Electrons2 sided
Photons
Item for irradiation~ 1.5 inches thick
‘Take home lesson’ from the dose distribution examples Photons (gamma rays or x-rays) allow delivery of a
uniform dose to a variety of sizes and shapes of food items
Electrons can be used to treat thin layers of product, but they cannot be used on objects greater than about 3 inches in thickness
Although the pictures were for meat products of various sorts, the dose distributions for treatment of different sized fruits would be similar to those seen with the meat products
Gamma and X-rays are both useful
Both can do the job
Technically the two are the same Effects of both on pests and product are identical Both have excellent penetration characteristics
Gamma ray systems are much simpler Decay is continuous
Gamma sources generally cost less for the power range required for disinfestation / lower capital cost
Gamma Processing CharacteristicsFunctional Requirement Gamma Capability
1 Ability to process a variety of products having a range of sizes and shapes.
Gamma can treat the entire gamut of sizes and shapes characteristic of agricultural commodities……..anything from cherries to watermelons.
2 Good dose uniformity over the entire processed lot of product.
Gamma can deliver a DUR of 1.5: 1, or better, in commercial product packs of all sizes, including pallet loads.
3 Convenient and economical interface with existing operations (packaging, transport)
Gamma can accommodate most existing packaging types and dimensions. The ability to treat fully loaded pallets provides a seamless interface with the distribution and warehousing system.
4 Reliability and system availability Gamma is intrinsically very simple. This translates into very high reliability and system availability.
5 Cost effectiveness Gamma's simplicity and scalability makes it very cost effective. You only install as much cobalt as you need, and install more when you need it.
The question of community acceptance of gamma systems…
Community acceptability of gamma facilities
Approximately 160 gamma-based teletherapy machines in hospitals all across America
Hundreds of research irradiators in labs across the country
Over 50 full scale production irradiators across the land
including some new ones
This attests to the general acceptance of gamma systems by society
Puerto RicoService
In-house
GAMMA FACILITIES IN USA
Puerto RicoService
In-house
GAMMA FACILITIES IN USA
Economic basics of gamma irradiators…….
Economics: capital cost estimate
Capital Cost of Pallet Irradiator for Disinfestation
(Illustrative only)
Component Cost range
(Million $ US)
Irradiator 3.0 5.0*Product conveying system
*Source operating mechanism
*Control and safety interlocks
Biological shield 0.8 1.5
Cobalt-60 0.5 1.0
Total 4.3 7.5
Land, warehouses, office space is not included.
Biological shield is constructed by local contractor
to MDS Nordion specifications.
Economics: unit processing costOperating Cost of Disinfestation Irradiator
(Illustrative only)
Operating and Facility Parameters
Capital cost 5775 k$ USThroughput 300 million lbs per yearDmin 0.15 kGyInstalled cobalt-60 0.27 MCiOperation per yr 7000 Hrs
Operating Costs (k$ US)
Capital depreciation $578 10 yr st lineCost of capital $347 Int or op cost @ 6%Replenishment cobalt $69Personnel incl labour $485 RSO,Mgr,QA,Maint,Ops,labourUtilities $25Overhead $200 Ins, spare parts, misc
Total $1,703 per year
Unit processing cost: 0.57 cents per lb
Unit processing cost vs annual throughput
Processing cost vs throughput
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1.00
2.00
3.00
4.00
5.00
6.00
7.00
0 50 100 150 200 250 300 350 400
Throughput (million pounds per yr)
Cen
ts p
er lb
Reference case
Economics summaryIrradiation is a capital intensive technology Typical systems run in the several million dollar range for
capital cost
Economics are favored by high throughputs Fixed costs are a major component of annual operating cost Unit processing costs are strongly dependent on volume
At sufficiently high throughput, they can be in the penny or two per pound range, or even less
Idle capacity is expensive Need to match system capacity to throughput needs
Gamma allows this easily Need to have ability to grow
Gamma allows this easily
MDS Nordion irradiators suitable for horticultural products……..
Key requirements in selecting an irradiation system……
MUST be able to process pallet loads We have non-pallet systems, but I will not talk about them
here
Product quality must not be compromised DUR capability must be low enough that the resulting
Dmax does not exceed the tolerance dose for the product Tolerable DUR is product-specific
Economics Low processing cost per lb / high throughput Capital cost must be affordable
MDS Nordion offers a choice….
For those products that can tolerate a fairly high DUR Parallel row pallet irradiator optimized to give the lowest
possible processing cost / highest capacity and most favorable processing economics
For those products that are more sensitive and require a tighter DUR
A new system, the Quadura, optimized to give the lowest possible DUR and the greatest flexibility, with still excellent processing economics
Parallel row pallet irradiator
• ~500 million pounds per year at 0.15 kGy
•16 pallets in chamber
•Nominal processing cost < 0.5 cent a pound
•DUR 2.50:1 at 0.40 g per cm3
•Cobalt use: > 50 poundsproduct processed per penny worth of cobalt consumed
Quadura …..pallet irradiator
QUADURA IRRADIATOR
STORAGE AREA
MAZE CONVEYORS
RADIATION SHIELDPartial view
IRRADIATORMECHANISM
QUADURA IRRADIATOR
TURNTABLETRANSFER TRAY ASS’Y
ADJUSTABLEAPERTURES (4X)
FOUR ROTATINGPRODUCT STACKS
COBALT 60ENERGY SOURCE
Quadura pallet irradiatorDUR < 1.5:1 for densities up to 0.6 g per cm3
Capacity up to ~ 300 million pounds per year at 0.15 kGy
Each pallet independently processed Maximum flexibility
Nominal processing cost < 1 cent a pound
Cobalt use: ~20 lbs of product processed for 1 cent worth of cobalt consumed ( at maximum capacity)
So what will it take to move forward?
Barriers to implementation of irradiation for disinfestation……..
And some initiatives MDS Nordion as a supplier to this industry is undertaking to help overcome them
Barriers to implementation
Regulatory restrictions USDA-APHIS umbrella regulation in place, but detailed
working agreements still needed before products can flow
High capital cost poses significant entry barrier Some budding enterprises find it difficult to raise the startup
capital
Logistical difficulties in providing service for distributed farming areas
Transportation required prior to irradiation Must be able to process product after it has been packaged for
transportation
Processing capacity not available New capacity needs to be built where needed
Problem: High capital cost poses significant entry barrier
Our initiative……
Convert part of the upfront capital cost of the irradiator into a processing charge based on the revenue stream generated by operation of the facility
This lowers the financial barrier for entry
It also shares the risk between the principal stakeholders
Problem: Logistical difficulties relating to transport to irradiation facility
Our response…..
We now offer a choice of two high performance pallet irradiation systems to meet the needs of the horticultural industry. This permits seamless integration of the irradiation facility into the normal transportation and distribution system used to get the product to market
Problem: Lack of processing capacity where needed
Our answer….
We’ll work with suitable counterparts from the horticultural industry to help make it happen
Summary and ConclusionRadiation disinfestation has an important role to
play as an integral part of the ‘agricultural export infrastructure’ serving a particular farming region
Irradiation systems are industrial facilities requiring multi-million dollar investments
Unit processing costs of less than a penny a pound are achievable at suitably high annual throughputs
Radiation disinfestation represents a ‘value added’ process. The magnitude of this added value can be very significant
State-of-the-art irradiators can process product on pallets, making it easy to integrate irradiation into the normal product transport and distribution system
Thank you !