ML042950344
| ML042950344 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png (DPR-061) |
| Issue date: | 10/13/2004 |
| From: | Gerard van Noordennen Connecticut Yankee Atomic Power Co |
| To: | Hill P NRC/FSME, State of CT, Dept of Environmental Protection |
| References | |
| -RFPFR, CY-04-191, FOIA/PA-2005-0203 | |
| Download: ML042950344 (3) | |
Text
CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD
- EAST HAMPTON, CT 06424-3099 OCr 1 3 2M4 CY-04-1 91 Mr. Peter Hill, LEP Bureau of Waste Management Connecticut Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Haddam Neck Plant March and June 2004 Sampling Events Semi-Annual Groundwater Monitoring Report
Dear Mr. Hill:
Connecticut Yankee Atomic Power Company (CYAPCO) hereby submits for your review the Semi-Annual Groundwater Report for quarterly groundwater sampling results from the March and June 2004 sampling events. Some key programmatic observations are:
- 1. As previously agreed, we have deferred quarterly groundwater sampling for the land disposal areas (200 Series monitoring wells (MW)) until after the Resource Conservation and Recovery Act (RCRA) remediation is complete. We anticipate sampling these wells again in December 2004.
- 2. CYAPCO continues abandonment of wells that are either unsuitable or unneeded for groundwater monitoring purposes; and
- 3. Six monitoring wells in the industrial area that were previously sampled quarterly have been abandoned in preparation for demolition and soil remediation. The June sampling event presents the last samples from AST-1, -2, -3, -4 and MW- 05S and MW-105D. Wells MW- 05S and MW-I 05D will be replaced following soil remediation in the service ally area.
Initial characterization of the bedrock boreholes at the Haddam Neck Plant (HNP) has been completed through a combination of packer tests, video camera logs, geophysical logging and hydrophysical logging. A series of bedrock monitoring wells will be constructed and is expected to be in place for inclusion in the December 2004 sampling round.
Mr. Peter Hill CY-04-1 91 Page 2 of 3 Summary of Groundwater Samnling Results Sampling was conducted in March and June 2004. In general, observed concentrations of substances of concern in groundwater continued to decline across the site. Tritium concentrations were below the 20,000 pCi/L maximum contaminant level (MCL) defined by the United States Environmental Protection Agency (USEPA) and State of Connecticut drinking water standard at all monitoring well locations sampled during both sampling events. Strontium-90 was observed to exceed the 8 pCi/L MCL in only one monitoring well (MW-105S). A significant downward trend from 91.8 to 16.2 (pCi/L) of Strontium-90 was observed at MW-105S. Discontinuing use and demolition of the tank farm is believed to have removed a substantial source of contamination in this area.
Planned removal of remaining contaminated soil beneath the tank farm area and the area next to the Primary Auxiliary Building (PAB) is expected to further reduce the contaminant source term. Cobalt-60 was detected in several wells during the June sample event, and a maximum concentration of 11.4 pCi/L was observed at MW-103S. Results at MW-103S represent less than 12% of the Co-60 MCL, which is 100 pCi/L.
Both unfiltered and field-filtered samples were collected and analyzed for substances of concern (SOCs) at several locations in the vicinity of the PAB and the Reactor Containment Building (RCB) in March. These methods were used to assess the presence of SOCs associated with suspended particulate in the groundwater. Although substantial variability in suspended solids and turbidity has been observed, the analyses did not indicate a substantial difference between filtered and unfiltered samples for the SOCs analyzed.
The maximum observed concentrations of selected SOCs and some general site trends based on the recent maximum concentrations are shown in the following table:
Maximum Observed Concentrations of Selected Substances of Concern for March and June 2004 Sam Elina vents March Location of June 2004 Location of Genr Substance 2004 March Maximum June Tendra maximum Maximum (pCi/L)
Maximum Trend Tritium 12,000 MW-103D 8,300 MW-11 OD Decrease Sr-90 92.4 MW-105S 16.2 MW-105S Decrease Boron 767 MW-105S 1260 MW-I 14S No Change Cs-137 22.4 MW-103S 7.5 MW-103S Decrease Co-60 3.2 MW-105S 11.4 MW-103S Increase
Mr. Peter Hill CY-04-1 91 Page 3 of 3 Recommendations for the Decembd& 2004 iampling event are as follows:
I. Initiate sampling at the landfill wells when completion of RCRA corrective actions at that location is confirmed;
- 3. Collect unfiltered samples only; and
- 4. Evaluate the potential for analyzing a reduced suite of SOCs, based on long-term non-detection of selected target analytes.
If you have any questions regarding this report, please call Doug Martin at (860) 267-2556 (x31 88).
Sincerely, 6M'O-Datej I
,2-0so Gerard P. van Noordennen Regulatory Affairs Manager
Attachment:
Semi-Annual Groundwater Monitoring Report CC:
Mr. Michael Firsick, CTDEP, Bureau of Radiation Protection Mr. Gary Ginsberg, CTDPH Mr. Ron Bellamy, USNRC Region 1 Mr. Jon Pekenpaugh, USNRC Region 1 Ms. Marie Miller, USNRC Region 1 Mr. Ted Smith, USNRC Headquarters Mr. Juan P6rez, USEPA Region 1 Mr. Marvin Rosenstein, USEPA Region 1 NRC Document Control Desk