# Presentation: 465319

## Issues Dealing With Safe Handlingof Mercury

- Philip T. Spampinato
- (spampinatop@ornl.gov, 865-576-5267)
- Tony A. Gabriel
- (_[gabrielta@ornl.gov](mailto:gabrielta@ornl.gov)_, 865-574-6082)

**Meeting on High-Power Mercury Jet Experiment**
**May 26-27, 2004**
**CERN**
**Geneva, Switzerland**

## Outline

- Properties, Safety Limits and Standards
- SNS Target Test Facility/WNR
- Installing Hg into the TTF
- Standard Hg Containers/Pallets
- Monitoring Hg Vapors
- SNS Hg Experience Installing New Equipment
- Conclusions

## Properties, Safety Limits, Standards

- Atomic Weight: 200.59
- Boiling Point: 357 degree C
- Specific Gravity: 13.6
- Vapor Pressure: 0.0012 mm Hg
- Vapor Density: 7.0
- Vapors: colorless, odorless
- Solubility: insoluble in water
- NIOSH/OSHA: 0.05 mg/m^3, 10 h/day; 40 h/wk
- Max. permissible exposure <0.10 mg/m^3

## Mercury Health Effects

**Table 1. Mercury Health Effects**

## Mercury First Aid Instruction

## Mercury Vapors

- Look at video clip that shows Hg vapors
- _[http://www.](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[deq](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[.state.mi.us/documents/](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[deq](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[-](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[ead](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[-p2-mercury-bb-Vapors.](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)__[wmv](http://www.deq.state.mi.us/documents/deq-ead-p2-mercury-bb-Vapors.wmv)_

## The Target Test Facility (TTF)Background Information

- Full scale, prototype of SNS Hg flow loop
- 1400 liters of Hg
- Used to determine flow characteristics
- Develop hands on operating experience
- Assess key remote handling design issues

## TTF Pump Room and Target Room

- 75 Hp centrifugal pump
- Nominal flow at 1560 liters/s (380 gpm)
- Completed several upgrades to the piping and target configuration

## Mercury Containers/Shipping

- 2 liter standard flask
- Flask weighs ~165 kg

## TTF Operations – Hg Filling

- Peristaltic pump was successfully tested
- Tipping fixture was tested but not used

## Filling (cont.)

- TTF vacuum pump was used to transfer Hg directly into the storage tank
- Lower risk than using the peristaltic pump
- Faster operation, ~ 1-1/2 minutes per flask

## TTF Access and Personal Protective Equipment – Minimum Requirements

## Mercury Monitoring

- TTF Uses Three Jerome 431-X Vapor Analyzers
- One monitor dedicated to each room, connected to the Target Test Facility PLC
- A portable monitor used during interventions
- The Jerome analyzer has a range of 0.000 – 0.999 mg/m3
- Sensitivity is 0.003 mg/m3
- Measures the change in resistance across a gold film as a function of Hg vapor
- Many other monitors are available

## Equipment Experience: Installation of He Bubbler

- Bubbler test equipment was recently added to TTF
- He leak tested all joints at 25 psig before filling with Hg

## Proper Dressing Is Mandatory 

- Overalls, gloves, and overshoes are the minimum requirement

## TTF Operations - Containment

- You cannot have too much containment!

## Mercury Puddling

- Mercury will collect into small droplets and large puddles even in pipes sloped at 1 degree

## Mercury Decontamination/Cleanup

- HgX is a water soluble, metallic-mercury/sulfide converting powder with a chelating compound and dispersing agent
- Forms a film over finely divided Hg beads, producing a non-vaporizing sulfide
- Mix with water as needed
- Apply with sponge
- Low cost

## Mercury Decon/Cleanup (cont.)

- HEPA Vacuum
- RCRA and non-RCRA waste collection

## TTF Ventilation System

- 5 air changes/h
- Flow velocity at 25-32 ft/s
- Sulfide-impregnated charcoal filter in line with the building ventilation

## Hg Was Used As An Anti-Friction Medium

- Hg was used as  bearing material in lighthouse lamp mechanisms
- the rotating mechanism floated in Hg

## Handling Activated Hg AddsAnother Level of Concern

- Small quantity of Hg was released somehow from handling the target

- Vapor monitor would have alerted the presence of Hg
- Herculite taped to floor area
- ~3 x 10^3 dpm/100 cm^2  contamination level

## Activated Hg (cont.)

- One person’s clothing was given up
- Everyone’s shoes were given up

- Contamination level although very low, was reportable
- Calculated to be micro- or pico-grams ??

## Conclusions

- ORNL has extensive experience handling Hg based on operating the TTF and other smaller test loops
- 1400 liters, full scale SNS flow loop
- Hg was installed with a vacuum pump; extensive use of spill containment; He leak check before operating
- Developed procedures for operating TTF and safe handling of Hg
- Numerous interventions have been undertaken to add/modify TTF test equipment
- Experience with dismantling pipe flanges, pipe cutting, and welding
- Vapor monitors always in use; decontamination using HgX and HEPA vacuum
- Handling activated mercury requires these same precautions and procedures, at an even higher level of alertness