ML052080060
| ML052080060 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 07/21/2005 |
| From: | Pace P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML052080060 (3) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 JUL 212005 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
In the Matter of the)
Docket No. 50-390 Tennessee Valley Authority)
WATTS BAR NUCLEAR PLANT (WBN) - OFFSITE DOSE CALCULATION MANUAL (ODCM) SPECIAL REPORT
Reference:
TVA Letter to NRC dated April 22, 2005, 'Watts Bar Nuclear Plant (WBN) - Offsite Dose Calculation Manual (ODCM) Special Report" This letter provides a Special Report in accordance with ODCM Administrative Control 5.4, "Special Reports," due to the exceedance of a limit defined in ODCM Control 1/2.3.1, "Radiological Environmental Monitoring Program (REMP)." The data in this report is the result of a routine tritium analysis performed by TVA's Western Area Radiological Laboratory during the second calendar quarter of 2005 of groundwater samples from onsite environmental monitoring point B. This groundwater onsite monitoring point is located in a down gradient position below the Yard Holding Pond (YHP) and the Intake Pumping Station (IPS). The analysis was performed on ODCM required composite four week samples as averaged over a calendar quarter. The analysis found the quarterly average tritium concentration at the monitoring point to be approximately 80,300 pCVL which exceeds the 30,000 pCVL ODCM concentration limit for tritium in non-drinking water pathway ground water samples. No tritium was detected in water samples from public drinking supplies. In addition, no other radionuclides were detected by a gamma scan at monitoring point B.
Pnmed on mcyed r,8
Nuclear Regulatory Commission Page 2 JUL 21 2005 On April 22, 2005, in the referenced letter, TVA addressed similar results for onsite environmental monitoring point D. This letter reflects the continuing migration of the groundwater plume. TVA believes that the most probable cause of the increased groundwater tritium levels is the movement of the plume from a previously repaired effluent line leak. Accordingly, the corrective actions for monitoring point B will be as previously stated for monitoring point D.
The tritium identified in the groundwater from monitoring location B does not present an increased potential risk for exceeding the limits for annual dose to a member of the public as specified in WBN ODCM Controls 1.2.1.2, 1.2.2.2 and 1.2.2.3. The available data indicates that the tritium is contained in a groundwater plume on the WBN site. The groundwater hydrology for the WBN site is such that the movement of this plume is toward the Tennessee River and does not present a risk for contamination of offsite groundwater sources. This tritium was included in the liquid effluent dose calculations for the site which were maintained below the annual limits for dose to a member of the public. TVA continues to monitor groundwater location B and other REMP groundwater locations in the path of the groundwater plume.
There are no regulatory commitments in this letter. Should there be questions regarding this report, please contact me at (423) 365-1824.
Sincerely, P. L. Pace Manager, Site Licensing and Industry Affairs cc: see page 3
U.S. Nuclear Regulatory Commission Page 3 JUL 21 2005 cc:
NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr. D. V. Pickett, Project Manager U.S. Nuclear Regulatory Commission MS 08G9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303