ML060960636

Tritium Monitoring Update to NRC and IEMA

ML060960636
Person / Time
Site:	Braidwood
Issue date:	11/30/2005
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2006-0115, FOIA/PA-2010-0209
Download: ML060960636 (9)

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Braidwood Station Tritium Monitoring Update to NRC and IEMA November 2005

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Topics

• B ackground

• May 2005 Sampling Results

• Development of Extended Sampling Plan

• Expanded Sampling and Characterization

• November 2005 Sampling Results

• Current Actions 2

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Background

Identified on-site low level tritium in storm water drainage ditch in northwest portion of property

- 04/01/05 (539 pCi/L)

- Background approximately 200-300 pCi/i

- Communications NRC, IEMA, IEPA

- Tracked back to area east of switchyard

- Increased existing sampling frequency of ditch

- Developed additional sampling plan

• Included installation of new monitoring wells

• Visual inspection of vacuum breaker pits 3

Background Cont'd May 2005 on site vacuum breaker pit inspection

- Vacuum Breaker #1 Leakage identified during observation

- Approximately 20 drops per minute

- Isolated immediately d

- Pit sample 51295 pCi/L

- Vacuum Breaker #2

• Showed no active leakage

- Vacuum Breaker #3

• Identified standing water in Pit

• Sample result - 1521 pCi/L

• No apparent leakage - likely from groundwater a/

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Development of Extended Sampling Plan

• Developed with assistance from professional environmental hydrologist (June 2005)

• Installed additional sampling wells & established sampling frequency

- 8 wells installed

• Located to identify potential sources and pathways

- Sampling began late September through late October 2005

• Initial results

- Elevated tritium in two wells (MW-103 and 113)

• Maximum 4480 pCi/L at MW-1 13; north of Vacuum Breaker 2 5

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Expanded Sampling & Characterization

• Multi-disciplined team developed

- On-site & off-site Exelon resources

- Contractor specialists

- Senior management leadership

• Objectives of team

- Identify historical and current sources

- Determine reportability requirements

- Identification of potential remediation options

- Development of communication strategy

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Expanded Sampling Cont'd

• Characterized relevant historical leakage areas

- Vacuum Breaker 3 (1998)

- Vacuum Breaker 2 (2000)

- Vacuum Breaker 1 (2005)

• Installed sampling wells along blowdown line to check for active leakage on site property

- Approximate 100 foot increments where access permitted

• Additional sampling wells established around vacuum breakers and historical leaks

- Includes property line along Smiley Road 7

Ca ( C November 2005 Sampling Results Areas affected by vacuum breaker leaks

- Sampling in area of Vacuum Breaker 3

• 729 - 58489 pCi/I

- Sampling in area of Vacuum Breaker 2

• 207 - 6193 pCi/I

- Sampling in area of Vacuum Breaker 1

• 206-1194pCi/1

• Blowdown line samples

- Highest 4058 pCi/l (near vacuum breaker 3)

- All others approximately background

• Results believed to be from historical leaks 8

C Current Actions

• Determine active leakage or not

- Additional sampling

- Third party review

• Implement offsite sampling plan

- Requesting permission from property owner

• Implement remediation plan

- Short term in progress today

- Long term actions under development

• Ongoing corrective actions will likely include enhanced routine surveillances

• Communications *

- NRC, IEMA, IEPA

- Braidwood Mayor

- State officials

- Potentially affected residents

• Provide periodic updates to-resident inspectors