BVY 10-039, Supplemental Special Report for Tritium Discovered Onsite
| ML102140400 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/26/2010 |
| From: | Michael Colomb Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BVY 10-039 | |
| Download: ML102140400 (3) | |
Text
Q Entergy Entergy Nuclear Operations, Inc.
Vermont Yankee 320 Governor Hunt Rd.
Vernon, VT 05354 Tel 802 257 7711 Michael J. Colomb Site Vice President BVY 10-039 July 26, 2010 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
REFERENCE:
Supplemental Special Report for Tritium Discovered Onsite Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28
- 1. Vermont Yankee Nuclear Power Station Off-Site Dose Calculation Manual, Revision 32
- 2. NEI 07-07, Industry Groundwater Protection Initiative - Final Guidance Document, dated August 2007
BVY 10-011, dated March 1,2010
Dear Sir or Madam:
This supplemental special report is submitted to provide updated information to the letter submitted by the Vermont Yankee Nuclear Power Station on March 1, 2010.
On January 30, 2010, water samples contained confirmed tritium levels in excess of the Vermont Yankee Nuclear Power Station (VY) Offsite Dose Calculation Manual (ODCM) reporting threshold and the NEI 07-07 voluntary reporting threshold of 30,000 picocuries/liter (pCi/L) for tritium in groundwater.
The table below shows the highest recorded sample data for wells containing tritium levels above minimum detectable levels as of June 24, 2010:
Well Number GZ-3 GZ-4 GZ - 07 GZ-10 GZ-11 GZ-12 GZ - 13D GZ-14 GZ - 14D GZ-15 GZ - 20 GZ - 21 Sample Date 05/24/2010 06/24/2010 03/17/2010 02/08/2010 05/03/2010 05/03/2010 02/24/2010 06/24/2010 03/04/2010 04/26/2010 03/10/2010 04/09/2010 Sample Results (in pCi/L) 169K pCi/L 29K pCi/L 1.22M pCi/L 2.52M pCi/L 3000 pCi/L 481 K pCi/L 2100 pCi/L 321 K pCi/L 2300 pCi/L 820K pCi/L 645K pCi/L 2.07M pCi/L AODq k10U
BVY 10-039 / page 2 of 3 The highest level of tritium measured was 2.52 million pCi/L.
It has been determined that there are no adverse affects on the health and safety of the public. VY calculations determined the dose is a fraction of a mrem annualized. The calculated annualized dose is small fraction of the 10 CFR 50 Appendix I dose limits. This calculation is on file for NRC review.
The causes of this event were inadequate housekeeping standards and practices that were applied during the construction of the advance off gas (AOG) pipe tunnel in 1972; inadequate design installation standards and practices during system modifications in 1978; and ineffective monitoring and inspection of the AOG pipe tunnel drain. Immediate corrective actions included termination of the leak, clearing the obstruction in the AOG pipe tunnel drain, removal of accessible debris from the tunnel and rerouting of drain lines. Planned corrective actions include redesign of the AOG pipe tunnel to ensure it is water tight, installation of AOG sump run-time monitors for enhanced leak detection, verification that other sump pumps have run timers and the establishment of surveillance activities for the AOG pipe tunnel.
Remediation of the tritium in the soil and groundwater is being funded as an operating expense and based on this will not significantly impact VY's decommissioning costs.
VY periodically communicates investigation results, sample activity results and actions taken to resolve the cause of the leak with key stake-holders.
This letter contains no new regulatory commitments.
Should you have any questions concerning this letter, please contact Mr. Robert J. Wanczyk at (802) 451-3166.
Sincerely,
[MJC/RAM]
cc list (next page)
BVY 10-039 / page 3 of 3 cc:
Regional Administrator U.S. Nuclear Regulatory Commission, Region 1 475 Allendale Road King of Prussia, PA 19406-1415 Mr. Jack Strosnider, Director U.S. Nuclear Regulatory Commission Office T8A23 Washington, DC 20555-00001 Mr. James S. Kim, Project Manager U.S. Nuclear Regulatory Commission Mail Stop 0 8 C2A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Rd Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601 Vermont Department of Health 108 Cherry Street Burlington, VT 05402 NH DHHS Division of Public Health Services Radiological Health 29 Hazen Drive Concord, NH 03301-4604 Mr. Robert Walker, Director Massachusetts Department of Public Health Radiation Control Program 529 Main Street Charlestown, MA 02129