# Presentation: 400048

## 

Bet Zimmerman
Environmental Services Division Manager

Brookhaven Executive Roundtable
Community Advisory Council
December 1999

**Bet Zimmerman**
- Environmental Services Division Manager
- Brookhaven Executive Roundtable
- Community Advisory Council
- December 1999

**Update on Tritium Investigation   ****Near g-2 Experiment**

## Summary

- BNL’s Groundwater Protection Program includes enhanced groundwater monitoring
- Detected tritium above drinking water standards near g-2 physics experiment
- Source is g-2 activated soil shielding, leaching by rainwater
- Solution is to redesign experiment to reduce activation and install cap to prevent leaching
- No tritium in drinking water supplies

## Groundwater Protection Program

- Relies on operational and engineered controls to prevent groundwater contamination
- Monitoring used to determine whether controls are effective and whether additional actions are needed
- BNL is installing over 80 new wells to monitor research and support facilities
- In early 1999, installed 4 new wells around the g-2 experiment to monitor potential soil activation areas

## G-2 Physics Experiment

**Notes:**
Located at center of site, approx. 1.8 miles from BNL boundary.

Smaller ring AGS.

## Existing Activated Soil Controls at V Target and g-2 Beam Stop

- Gunnite Cap Over g-2 Beam Stop

- Rubber Membrane Over g-2 Target Cave

- Paved Area
- Extends Underneath Target Hall And
- Beam Stop

## Groundwater Monitoring Results

- In November, tritium higher than drinking water standard seen at Well 054-067
- Launched investigation to:
- Verify according to plan
- Characterize nature and          extent of contamination
- Identify source
- Installed 18 Geoprobes, collected samples from various depths

## Groundwater monitoring locations

## Results

- Pencil-shaped plume ~ 30 ft wide x 250 ft long
- Tritium (drinking water standard 20,000 pCi/L)
- ~38 of 74 samples near or below detection limits for tritium
- Highest tritium concentration 1.8M pCi/L, 70 feet from source
- Sodium-22 (drinking water standard 400 pCi/L)
- ~28 of 40 nondetect for sodium-22
- Highest sodium-22 concentration 60 pCi/L
- Tritium + sodium-22 indicates soil activation
- Source is soil activation next to VQ12 magnet that is part of g-2 experiment
- Nearest BNL drinking water well monitored monthly--no tritium detected

## Corrective Actions

- Tune particle beam to minimize soil activation.  Monitor effectiveness.
- Continue groundwater monitoring.
- Model to ensure monitoring system is adequate.
- Installed expanded concrete cap to prevent rainwater from leaching activation products out of soil.

## Activated Soil Near VQ12 Magnet

- ........................................

- ........................................

- ........................................

- ........................................

- Groundwater Table

- EL 45’

**New Rain Barrier**

- Soil Shielding

- Beam re-tuned to reduce impact on VQ12 Magnet

- Activated Soil

**Activated Soil Near VQ12 Magnet**

## Conclusion

- Systematic approach identified a problem.
- Within weeks, Investigative Team determined extent of contamination and source, and BNL is fixing the problem.
- Tritium not threatening drinking water supply
- Tritium not expected to move offsite at detectable levels.
- In the future, possible that enhanced monitoring system may detect other problems.
- If this occurs, we will use monitoring data to help determine what corrective actions are needed.
**Must continue to work hard to control or eliminate pollution at the source in order to protect groundwater quality.**