1. Level B Suit Mock Up August 29, 2013 Duane F. McLane
AMWTP ES&H Manager

2. Problem
In 2013, the AMWTP has experienced 5 skin contamination events that resulted from work being performed in the Treatment Facility boxlines during maintenance and operations activities.
Three of the events occurred in August 2013.
In all of these entries a trend of finding contamination on either the inner left and/or right bicep has occurred.
As a result of these contamination events, management suspended all Level B suit activities on the project.
ES&H, Maintenance and Operations developed a mockup to test the Level B suits to recreate the failure mode of the PPE in a controlled environment and to develop corrective actions and compensatory measures to safely resume work.

3. Mock Up Plan
A team of ES&H professionals, including Maintenance and Operations technicians and representatives from the ESIT, was assembled to develop the mockup plan and entry teams.
The objective was to develop cell entries with realistic conditions that would simulate the working conditions of a cell where the contamination events have occurred.
Activities included motor repair and housekeeping for a full 2.5 hour entry.
The mock-up area will be contaminated with a non-hazardous powder that can simulate radiological contamination. The powder can be seen using a black light.
The objective was to determine why and or where the contamination/powder is entering the suit, transferred through the Tyvek PC and to the skin.
By determining how contamination is entering the suit, then corrective actions to prevent the contamination migration into the suit can be identified/tested.

4. Mock Up The mock up was set up in room 232 in the Treatment Facility.
Room 232 is ideal as it is configured similarly to the cells in the facility.
It has negative ventilation flowing through air-locks and then into a suit change room with a breathing air manifold, then on to the suit prep room, and finally into the cell.
The following are pictures of the mock-up area in room 232:

5. Mock Up

6. 8/27 Entry
Entry was made into room 232 to perform simulated work of housekeeping and some maintenance activities.
There were three entrants on this first entry: one operations technician and two maintenance technicians.
The entrants were configured in a full set of anti-c with the MSA-supplied breathing air system and the Rich Industries Level B suit.
All of the exhaust valves were covered with a protective breathable material.
The entrants were given a 2.5 hour heat stress stay
time with a 45/15 minute work rest determination
based on moderate work activities.
The first entrant had to leave after 20 minutes
due to a breach in the back of the suit on a seam.
Upon exiting contamination (chalk powder) was
discovered near where the breach occurred on
the inner Tyvek® but not under the Tyvek® on
the green scrubs nor on the skin.

7. 8/28 Entry
The activities for the mock-up in room 232 were performed using three maintenance entrants.
The work being simulated was to rebuild a quick hitch and housekeeping. Entrants were donned in the same PPE as the day before and the heat stress conditions were the same (2.5 hour stay time with a 45/15 work rest determination).
Two of the entrants were of large stature and one of them has a small stature.
The first entrant exited after 1.5 hours and had a small amount of contamination detected on his lower forearm on his inner anti-cs. No skin contamination was identified.
The second entrant exited the area after about 1.45 hours and was the entrant of small stature. There was no contamination found on this individual anywhere but it is important to note that he was very wet due to sweating/condensation.
The third (and largest) entrant exited after about 2 hours. Contamination was found quite extensively under the zipper flap and on the outer zipper. There was also contamination found on the upper arm, bicep areas of both arms on the outer Tyvek® and under both arms. Further evaluation found significant contamination on his skin located on the inner area of the right bicep.
Evaluation of the suit from the third entrant showed degradation of the suit material
of the right arm pit area as the contaminant had migrated through suit material.

8. Entry 8/28

9. Entry 8/28

10. Entry 8/28

11. Results
Failure of suit from tearing/seam on workers who challenge suit size.
Failure of suit from migration in arm pit on worker who challenged suit size.
Excessive sweating/moisture contributes to both suit and Tyvek failure.
Failure of Tyvek when too wet from inside and outside.

12. Moving Forward Immediate Actions: Long Term Actions
Continued mockup to validate/test
Cotton blend PCs
Moisture buildup (no head vent)
Determine size limitations
Evaluation of arm pit area
Contact Rich Industries
Degradation
Shelf life
Check BA dryer systems
Long Term Actions
Suit enhancements
Relocate pressure valves
Reinforcement in arm pits
New zipper design
Common worker locations
Sleevette sizes
Long sleeve greens
Maintain mockup