0CAN062403, Groundwater Protection Initiative - Voluntary Special Report for Tritium Levels
| ML24177A179 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/25/2024 |
| From: | Keele R Entergy Operations |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 0CAN062403 | |
| Download: ML24177A179 (1) | |
Text
- ) entergy 0CAN062403 June 25, 2024 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Riley D. Keele, Jr.
Manager, Regulatory Assurance Arkansas Nuclear One Tel 479-858-7826 10 CFR 50.4
Subject:
Groundwater Protection Initiative - Voluntary Special Report for Tritium Levels Arkansas Nuclear One - Units 1 and 2 N RC Docket Nos. 50-313 and 50-368 Renewed Facility Operating License Nos. DPR-51 and NPF-6 This voluntary 30-day report is being made in accordance with Nuclear Energy Institute (NEI) 07-07, Rev. 1, Industry Ground Water Protection Initiative - Final Guidance. On June 3, 2024, Arkansas Nuclear One (ANO) received the results from a well sample which indicated a tritium level of 335,500 picocuries per liter (pCi/L). An additional sample was collected on June 12, 2024, which had a tritium level of 1,028,000 pCi/L. This tritium level exceeds the ANO Offsite Dose Calculation Manual (ODCM) threshold value for a potential drinking water pathway and constitutes voluntary reporting in accordance with NEI 07-07.
The source of the elevated tritium levels is associated with the overflow of 440 gallons of the Borated Water Storage Tank (BWST) inventory which occurred on May 11, 2024. An 8-hour Event Notification57123 was made to the NRG in accordance with 1 0 CFR 50. 72(b )(2)(xi) as a result of notifying the State of Arkansas. Assuming all 440 gallons was released to the discharge canal during the time of overflow, the attributable tritium dose was 1.41 E-07 millirem (mrem).
ANO has taken immediate actions by excavating the affected soil. The site then placed a herculite tarp over the excavated area to minimize or prevent stormwater runoff. In addition, sump pumps were installed on top of the herculite tarp to pump captured stormwater and routed to ODCM-approved effluent pathways. On June 20, 2024, a permanent concrete cap was poured over the area to prevent any remaining isotopes in the soil from being washed away during storm events.
ANO continues to monitor the groundwater table for both tritium and gamma radionuclides. Due to their particulate nature, gamma radionuclides are not expected to migrate through the soil.
Therefore, it is not expected to see gamma radionuclides exit the site boundary. A new Entergy Operations, Inc. 1448 S.R 333 Russellville, AR 72802
0CAN062403 Page 2 of 2 monitoring well in the groundwater flow path has been installed where groundwater may enter Lake Dardanelle. The new well will allow ANO to monitor potential dose to the public should the tritium migrate. However, ANO will include all tritium dose attributed to this event in one release (1.41 E-07 mrem) in the site's annual effluent report.
There are no new commitments contained in this letter.
Should you have any questions or require additional information related to this report, please contact Garen Holman, Acting Chemistry Manager, at (479) 858-4431.
Respectfully,
~¥~
Riley Keele RDK/dkb cc:
NRG Region IV Regional Administrator NRG Senior Resident Inspector - Arkansas Nuclear One NRG Project Manager - Arkansas Nuclear One NRG Document Control Desk State of Arkansas