Reusables vs. Disposables A Comparative LCA of Radioactive Protective Equipment
John Jewell, PE INTERNATIONAL Maggie Wildnauer, PE INTERNATIONAL
Agenda
1. Project Summary 2. LCA Results 3. Conclusions
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Project Summary
Background Protective suits are used primarily when nuclear power plants shut down for cleaning. They are worn for short intervals. Suits must be removed when leaving radioactive zone and a new suit used when re-entering.
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Goal & Scope Goal:
Comparative LCA of reusable and disposable radiation suits
Scope:
Cradle-to-Grave LCA, including: coveralls, shoe covers, rubber shoes, rubber gloves, hood, and scrubs
Functional Unit: 1 wearing event to protect from low-level radioactive particulate contamination Data Collection:
- Primary data from UniTech, 2012 - Secondary data from relevant literature - Upstream and downstream material and energy data from GaBi 2012 LCI Databases
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Reusable Protective Garment Set
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Coverall
ProTech Nylon with antistatic carbon fiber
Hood
ProTech Nylon with antistatic carbon fiber
Gloves
Rubber
Scrub Top
CoolTech PET with antistatic carbon fiber
Scrub Bottom
CoolTech PET with antistatic carbon fiber
Shoes
Rubber
Shoe Covers
Nylon
Laundry Bag
Nylon and PVC
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Disposable Protective Garment Set
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Coverall
PVA Fabric
Hood
PVA Fabric
Gloves
Rubber
Scrub Top
PVA Fabric
Scrub Bottom
PVA Fabric
Shoes
Rubber
Shoe Covers
PVA Fabric
Laundry Bag
PVA
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System Boundary Cradle-to-Grave
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Data Collection - Reusables Reusable Protective Garment Set n uses Garment Manufacturing
Wearing Event
Laundry
Landfill
Raw Materials ProTechR Nylon w/carbon fiber CoolTechR PET w/carbon fiber Nylon fiber Rubber PVC Manufacturing Cotton Inc. woven fabric manufacturing dataset
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Transport 320 mile delivery / pickup for each use
Laundry UniTech laundry details • Energy • Water • Emissions • Failure rates UniTech calculates number of uses based on each garment’s average rate of failure during radiation tests.
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Data Collection - Disposables Disposable Protective Garment Set Garment Manufacturing
Wearing Event
PVA OREXÂŽ garment production is detailed in an earlier LCA by SKM Enviros.
Dissolution and disposal
PVA dissolves in the presence of hydrogen peroxide & a catalyst. Byproducts are water, CO2, and small amounts of vinyl acetate – remaining rubber, etc. are incinerated.
(PVA) C2 H4 O + 5H2 O2
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(VAM) C4 H6 O2 + 9H2 O2
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2CO2 + 7H2 O
∆ đ??šđ??šđ??šđ??šđ??šđ??šđ?‘‚đ?‘‚4
4CO2 + 12H2 O
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LCA Results
Life Cycle Impact Assessment TRACI 2.1 Impact Categories: − Global Warming Potential (GWP)
[kg CO2 eq]
− Acidification Potential (AP)
[kg SO2 eq]
− Eutrophication Potential (EP)
[kg N eq]
− Smog Formation Potential (SFP)
[kg O3 eq]
− Ozone Depletion Potential (ODP)
[kg CFC 11 eq]
Environmental Indicators: − Primary Energy Demand (PED)
[MJ lower heating value]
− Net Water Consumption (Water)
[L water]
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Reusables’ results by life cycle stage
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Disposables’ results by life cycle stage
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Comparative Results Global Warming Potential [kg CO2 eq / use] Materials
Transportation
Laundering
End-of-Life
Reusable
Disposable
0
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2
4
6
8
10
12
15
Comparative Results Eutrophication Potential [kg N eq / use] Materials
Transportation
Laundering
End-of-Life
Reusable
Disposable
0,0E+00
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5,0E-04
1,0E-03
1,5E-03
2,0E-03
2,5E-03
3,0E-03
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Comparative Results Water Consumption [Liters / use] Materials
Transportation
Laundering
End-of-Life
Reusable
Disposable
-10
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0
10
20
30
40
50
60
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Additional Impact Categories Ozone Depletion (kg CFC 11 eq / use)
Acidification (kg SO2 eq / use)
2,6E-02
1,1E-09
1,2E-09
Disposable
Reusable
Disposable
8,1E-03 Reusable
Primary Energy Demand (MJ / use)
Smog Formation (kg O3 eq / use)
1,7E+02
3,2E+01 Reusable
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5,1E-01
9,0E-02 Disposable
Reusable
Disposable
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Sensitivity Analysis Reusables win after about 4 uses
Lifetime Uses Single Break Baseline Use Even Coverall
1
3
48
Gloves
1
2
9
Hood
1
3
200
Shoes
1
2
23
1
3
88
1
3
200
1
3
200
1
3
140
Shoe covers Scrub Top Scrub Bottom Laundry bag
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Conclusions
Conclusions & Recommendations Reusables’ impacts are dominated by use phase washing and to a limited extent, raw materials.
Disposables’ impacts are driven by raw materials, followed by transportation.
Reusable protective garments have lower impact than disposables in every impact considered. Though reusables have reduced environmental impact, improvements related to washing energy and water use would further minimize the burdens attributed to reusable garments.
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Incorrect PVA data used in other LCA GWP (kg CO2-Equiv. / kg) 8,78 (Poly)Vinyl Acetate
Hydrolysis
Polyvinyl Alcohol
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2,06
1,99
SKM Enviros: Polyvinyl Acetate
PE: Vinyl Acetate
PE: PVA
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Questions? For more information contact Gregg Johnstone gjohnstone@unitechus.com or Mike Fuller mfuller@unitechus.com at UniTech