Lead Test Assemblies
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Lead test assembles (LTAs) are fuel assemblies that contain design features or materials that have not been approved for unrestricted use in the reactor core. LTA irradiation campaigns provide knowledge of and experience with irradiated material properties and performance, which is critical for qualifying analytical codes and methods and for developing the design bases to license new fuel material or design features for unrestricted use. In particular, the campaigns are intended to accomplish the following tasks:
- collection of data to characterize irradiated material properties and performance;
- provision of irradiated material for subsequent hot-cell examination, characterization, and research;
- demonstration of in-reactor performance.
LTAs have been loaded in operating reactor cores safely over the past several decades. Licensees may request a license amendment to insert LTAs, or they may be inserted without additional NRC approval through the change process in 10 CFR 50.59.
To clarify and provide regulatory certainty around the use of 10 CFR 50.59 with LTAs, the NRC issued a guidance letter to industry on June 24, 2019.
Several U.S. power reactor licensees have inserted LTAs with ATF technologies, which are listed below. Other technologies may be loaded into LTAs and inserted in reactor cores in the future.
Coated Cladding
Plant |
Licensee |
Fuel Vendor |
Date(s) Inserted |
Hatch |
Southern Nuclear |
GE/GNF |
Spring 2018 and Spring 2019 |
Vogtle |
Southern Nuclear |
Framatome |
Spring 2019 and Spring 2020 |
ANO-1 |
Entergy |
Framatome |
Fall 2019 |
Clinton |
Exelon |
GE/GNF |
Fall 2019 and Spring 2021 |
Calvert Cliffs |
Constellation |
Framatome |
Spring 2021 |
Limerick |
Constellation |
GE/GNF |
Spring 2021 |
Monticello |
Xcel |
Framatome |
Spring 2021 |
Doped Pellets
Plant |
Licensee |
Fuel Vendor |
Date(s) Inserted |
Byron |
Exelon |
Westinghouse |
Spring 2019 and Spring 2020 |
Vogtle |
Southern Nuclear |
Framatome |
Spring 2019 |
ANO-1 |
Entergy |
Framatome |
Fall 2019 |
Calvert Cliffs |
Constellation |
Framatome |
Spring 2021 |
FeCrAl Cladding
Plant |
Licensee |
Fuel Vendor |
Date(s) Inserted |
Hatch |
Southern Nuclear |
GE/GNF |
Fall 2018, Spring 2019, and Spring 2021 |
Clinton |
Exelon |
GE/GNF |
Fall 2019 and Spring 2021 |
Uranium Silicide Pellets
Plant |
Licensee |
Fuel Vendor |
Date Inserted |
Byron |
Exelon |
Westinghouse |
Spring 2019 and Spring 2020 |
Page Last Reviewed/Updated Thursday, February 09, 2023