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Steve Neilson, CIH U.S. Department of Energy Thomas Jefferson Site Office DOE and DOE Contractor Industrial Hygiene Meeting 2012 Industrial Hygiene Conference.

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Presentation on theme: "Steve Neilson, CIH U.S. Department of Energy Thomas Jefferson Site Office DOE and DOE Contractor Industrial Hygiene Meeting 2012 Industrial Hygiene Conference."— Presentation transcript:

1 Steve Neilson, CIH U.S. Department of Energy Thomas Jefferson Site Office DOE and DOE Contractor Industrial Hygiene Meeting 2012 Industrial Hygiene Conference and Exhibition, Indianapolis, IN June 18, Construction Project Silica Exposures and Observations at the Thomas Jefferson National Accelerator Facility

2 Thomas Jefferson National Accelerator Facility (TJNAF) 800 Employees, 1300 User Community 6 GeV Continuous Electron Beam Accelerator 3 Experimental End Stations for Nuclear Physics Research Free Electron Laser (FEL) Facility SRF Institute Center for Theoretical and Computational Physics Theoretical Physics 2

3 Construction Projects 12 GeV Upgrade Project o $ 310 Million Dollars o Combination of Civil Construction and Equipment Upgrades New experimental end station, tagger, and related infrastructure Additional cryomodules to the existing accelerator Upgrades to existing experimental end station detectors o Civil Construction Phase was Completed January 2012 Technology, Engineering and Development Facility Project (TEDF) o $ 73 Million Dollars o Combination of New Construction and Renovation Technology and Engineering Development (TED) Building (complete) 30,000 SQF addition to Test Lab Renovation of over 90% of the 96,000 sq. ft. Test Lab (former NASA Synchrotron facility) o Projected Completion Date is March

4 Event #1 Task o Removal of a wedge shaped section of the new concrete floor slab to accommodate pouring a slab between the new tunnel and the existing Accelerator tunnel floor Work Environment o Tunnel cross section dimensions roughly 8 wide x 7tall, in a cul-de-sac configuration (temporary wall to accelerator arc is located about 30 away) o 12 hour shifts Tools and Techniques o Jackhammers – 3 different sizes o Garden hose wetting manually applied to chisel impact zone o Hurricane Fans 4

5 Work Conditions The area was visited during the conduct of a Joint Construction Safety Walkthrough Work had stopped momentarily for a scheduled break, so jackhammering had not been active for some number of minutes prior to arrival. Visible suspended dust was present along a fairly long section of the new tunnel Garden hose and wet floor indicated the workers intent to suppress dust Hurricane fans staged in various locations along tunnel Due to the suspended concrete dust concern, the General Construction Contractor agreed to suspend work until respiratory protection was applied and air sampling was conducted 5

6 Outside view of the Tagger Tunnel 6

7 Tagger Tunnel from the Inside Note the area sample being collected with a nylon cyclone attached in the top left corner of the photo, and the placement of the hurricane fans 7

8 Breathing zone and area air sample collection Workers outfitted for the collection of a breathing zone sample for respirable silica. 8

9 Jackhammer Operation Jackhammer Operation Water was continuously applied at the jackhammer point of impact 9

10 Event #1 Monitoring Results Close agreement between area and breathing zone air samples o Percent crystalline quartz = 35% o JLab area sample TWA = mg/m3 o Contractors BZ sample TWA = 0.66 mg/m3 12-hour adjusted PEL and TLV for respirable crystalline silica (quartz) o PEL = 0.18 mg/m3 o TLV = 0.03 mg/m3 Respirator MUC of 0.3 mg/m3 (half mask tight fitting respirator with HEPA filters) would not provide adequate protection for the 12 hour work shift. 10

11 Event #2 Task o Concrete floor slab removal because new slab was poured too thick for future alignment with sky bridge between new and old building. Work Environment o Interior stairwell landing Tools and Techniques o Jackhammer o Manual wetting of slab and jackhammer chisel area with water spray o Manual load-out of rubble in 5 gallon buckets o Wearing disposable, filtering facepiece respirators 11

12 Event #2 Monitoring Results Area sample collection by Lab CIH indicated collection location is considered to be representative of breathing zone exposure. (no sampling initiated by GC) o Percent crystalline quartz of bulk dust = 26% o Respirable crystalline silica area sample TWA = mg/m3 (exceeds ACGIH 2005 TLV of 0.05 mg/m3) Respirator protection factor could not be applied since the worker had not been fit tested, trained, or medically qualified for the filtering facepiece respirator (N-95) worn at the time of this activity. 12

13 Similarities Indoor work activities over multiple days of exposure Workers exposed above the TLV Jackhammering Wet methods % crystalline silica in the same general ball park Attempts at ventilation control having limited beneficial effect. Lack of work planning o One Contractor was essentially completing final actions before demobilization (construction phase was all but finished) o Other Contractor was trying to make up schedule from the rework (pouring initial slab too thick). 13

14 Additional Construction Related Silica Observations Two different events, separated by a couple days Both were dry brick cutting outdoors In at least one case, the saw was equipped and designed for wet cutting In both cases, the work was not performed in accordance with documented work plans that required wet cutting OUTCOME Contractor issued $10,000 fine by the Laboratory for failure to perform work in accordance with safety requirements 14

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16 Additional Corrective Action Taken (not comprehensive) Mandatory silica hazard training for all construction workers Activity Hazard Analysis documents audited for construction contractor New work planning form (permit) created for work that has silica exposure potential Lab developed a resource document for subcontractors to highlight where the 2005 TLVs are more restrictive than the PELs Master Spec contract language revised on silica exposure controls and monitoring expectations Laboratory Subcontracting Officers Technical Representatives (SOTRs) were given silica awareness training and specific responsibilities on evaluating work having silica exposure potential Additional oversight at construction projects by Lab ES&H staff 17

17 Collective Challenges For the Department Dont presume your contractor understands the impact of 10 CFR 851, or the hazards of silica o Moving from conventional notion of dust to the respect necessary with silicosis/carcinogen o The TLV and PEL are worlds different o Construction contractors will incorrectly presume that any wet method is satisfactory o A bucket of paint comes with a MSDS, a concrete slab doesnt Effectively imparting Lessons Learned information to construction contractors (GC and their lower-tiered subs) o One of the sentiments held after event #1 was this particular contractor was on their way out the door – good riddance and we wont have to worry about that again. Obviously it was later confirmed that this vulnerability was shared with other on-site construction contractors 17

18 Challenges (continued) Dont immediately defaulting to respiratory protection o Observation of the dry brick cutting tasks are indicative of a generally used approach to simply put on a dust mask, which is simply not compliant, and may not be enough. o There are commercial, off-the-self solutions such as local exhaust snorkels for drilling, jackhammering, and sanding. Control at the point of application may also have a side benefit of managing overall housekeeping 18

19 Challenges (continued) What if the subcontractor is not initially compelled to sample activities of concern? o One option is to collect your own area samples Advantage – non-invasive and shouldnt interfere with work Disadvantages a) Area samples may not be good surrogates for BZ exposures for compliance – could be contentious with the subcontractor. b) The Lab becomes a crutch. Its the subcontractors responsibility as the employer under 851, and they must be held accountable for evidence of the effectiveness of work controls o Better Alternative – Incorporate plain contract language to emphasize the subcontractor has full responsibility for providing evidence of exposure control effectiveness, but the Lab retains the right to collect their own samples for evaluating contract compliance at their discretion. This should reduce the likelihood of the subcontractor filing claims because you negatively impacted their schedule and cost. 19

20 Commercially Available Local Exhaust Systems Exist 20

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