1. Braidwood Generating Station
Tritium Review Presentation to RETS/REMP Workshop June 26, 2007

2. Braidwood Station Background
Dual-unit Westinghouse pressurized water reactors
Construction permit December 1975
Unit One operation July 1988
Unit Two operation October 1988
(Initial operating licenses good for 40 years)
Generation capability Unit 1 – 1248 MWe Unit 2 – 1224 MWe
Number of employees 615 (Exelon)

3. Circulating Water Blowdown Line
Station exchanges clean water with Kankakee River for cooling lake through circulating water make up and blowdown lines
In addition, blowdown line caries periodic discharges of liquid radioactive waste
Tritium is principal component; other activity is significantly reduced via radwaste system (filters, demineralizers, RO)
Prior to 11/05, discharges 2-3 times per week
Discharge concentration limits contained in offsite dose calculation manual (ODCM)
10 times limits in 10 CFR Appendix B
For tritium, concentration limit is 1 E+7 pico-curies/liter
Non-radiological aspects of discharge regulated by NPDES permit

4. Circulating Water Blowdown Line

5. Chronology Three significant VB leaks 1996-2000
VB-1: 11/96, ~380K gallons
VB-3: 12/98, ~3M gallons
VB-2: 11/00, ~3M gallons
Inadequate response at the time
IEPA questions raised regarding Godley; sampling initiated - 3/05
Environmental contractor engaged to install sampling wells - 6/05-11/05
Identified elevated groundwater tritium concentrations near site border - 11/05
Ceased liquid radioactive releases – 11/05
Formed issues management team and root cause team – 11/05

6. Issues Management Team Role
Characterize source and extent of contamination
Develop and implement remedial action
Coordinate/support external response efforts
Public outreach/media response
Regulatory
Government
Legal
Real estate
Support root cause team

7. Regulatory Issues NRC Illinois EPA
Violations for failure to document and assess impact of releases
Low to moderate safety significance (white)
Oversight of characterization and remediation efforts
Illinois EPA
Lead agency is Bureau of Water
Violation Notices for exceeding IEPA groundwater quality standard and non-degradation standard
Exelon community relations plan
Jurisdictional issues for regulation of radioactive releases

8. Key Learnings
Historic insensitivity to blowdown spills
Lack of knowledge of State groundwater regulations
Exelon functional area gaps for radiological spills
IEPA sensitivity to “Right to Know”
Issues management process

9. Areas for focused site characterization reports
Description of Sites
Areas for focused site characterization reports
Areas near VB 1 and VBs 2,3
VB 4
VB 6
VB 7
West side of turbine building
Other areas investigated - no tritium identified
Blowdown line between VB 1 and 3
River screen house (past VB 11)

10. Regional Geology

11. Sampling and Analysis Locations

12. Additional Studies Comprehensive water level measurements
Area wide well inventory
Review release logs to estimate curies released from VB leaks
Tritium dating study in VB 2,3 plume area
Chemical analysis of groundwater/blowdown water
Pipe integrity test
Modeling of transport

13. Regional Groundwater Use
Wells are screened as follows
Shallow aquifer (25-30 feet)
Private wells
Shallow bedrock ( feet)
Deeper bedrock ( feet)
Some private wells
Municipal wells
Deepest bedrock ( feet)

14. Tritium in groundwater is consistent with historical releases from VBs
Key Conclusions
Tritium in groundwater is consistent with historical releases from VBs
Migration will not result in impact on private wells above the groundwater standard
Additional conclusions and observations
VB-1 VB 2-3
VB-4,6,7

15. Currently pumping from pond on Exelon property (Exelon Pond)
VB 2,3
Objectives
Prevent migration into uncontaminated areas
Recover contaminated groundwater
Use a method that can be implemented quickly, with already licensed and permitted disposal methods
Currently pumping from pond on Exelon property (Exelon Pond)
Most immediate effect on northward migration
Will supplement this action with additional remediation actions based on modeling

16. Exelon Pond Pumping System

17. Blowdown Line Integrity
Operate line water solid
Sealed bottom of VB vaults
Installed continuous leak detection system
Hydraulic transient analysis of line
Weekly inspections of blowdown line corridor

18. Action to Suppress VB-1 Plume
VB-1 plume is leaching into site perimeter ditch
Installed temporary weir in ditch to raise level of surface water
Installed in 3/06
Stop partially penetrating influence of ditch
Result - slow downward trend in sample results at weir
Removed in fall of 2006 after successful implementation of remediation system
Installed remediation system consisting of 3 wells.

19. Dose Assessment
Performed by independent three member team with significant industry experience
Independent review – Dr. John W Poston
Methodology highlights
Multiple exposure pathways considered
Results include past, current, and hypothetical future dose
Methodology consistent with Regulatory Guide (1977)
Volumes and concentrations released based on plant release logs and soil samples

20. VB-2, VB-3 Related Scenarios
Private Well 8 Potable Water
Well Drinking Water
Garden Irrigated with Well
Exelon Pond
Swimming
Eating Fish Living In Pond
Eating Deer Drinking From Pond
Eating Goose Drinking from Pond
Smiley Ditch VB-2, VB-3
Eating Deer Drinking from Smiley Road Ditch
Direct Dose from Smiley Road Ditch
Spill Water at VB-3
Deer drinking water eating contaminated vegetation

21. VB-3 Multiple Nuclide Scenarios
Deer drinking ponded spill water, eating contaminated vegetation around vacuum breaker pit.
Direct shine to members of public on Smiley Road from potential soil contamination in ditch.
No direct sample data from 1998 spill
Soil sample data from (g) available
Tank release data from 1998

22. Summary of Calculated Doses

23. Root Cause Analysis Responses to spills varied; none were adequate
1996 and 1998 spills treated as water spills; no sampling or cleanup
2000 spill was sampled and cleaned up; no consideration of impact on ground water
Root cause is lack of integrated procedural guidance
Environmental spill response procedures not intended for radioactive spills
Radiological documentation procedure does not consider impacts on groundwater, hydrology, groundwater regulations
Additional root cause is lack of management oversight
Review of condition reports
Inadequate follow-through for 2000 spill

24. Root Cause Corrective Actions
Develop integrated spill response procedure
Develop methodology for future releases
Increase rigor in issues management process
Case study for management aspects
Other actions address training, procedure enhancements
Previous actions to prevent catastrophic VB failures
Appear effective based on performance since 2000
Did not address small VB leaks
Action to consider alternate methods for releases

25. Release Reduction Recycle modifications Volume reduction modifications
Clean up radwaste to primary grade water
Reverse osmosis/demineralizers
Use existing primary water storage tanks
Volume reduction modifications
Condensate re-route (chillers and aux steam)
Floor drain re-route (reduces organic input)
Reduction of over 1M gal/year input to radwaste
Long-term optimization
Production
Recycle
Release (electrolysis, liquid release)