Reactor D&D: Recent Achievements and Innovations in the U.S.

AUTHORS
Daphne Ogawa, Sylvie Kramer, Matt Lucas, Sebastien Guillot
Orano Decommissioning Services, LLC

PRESENTING
August 28, 2023
The 7th International Forum on the Decommissioning of the Fukushima Daiichi Nuclear Power Station, Japan

ABSTRACT

With more than 10 projects to date in the U.S. and Germany, Orano has gained a comprehensive expertise in successfully dismantling the full spectrum of boiling water reactors (BWR) and pressurized water reactors (PWR), including the segmentation, packaging, transportation, and disposal of the Reactor Vessel (RV) and Reactor Vessel Internals (RVI).

In the U.S., Orano recently completed the first full segmentation of a commercial BWR (Vermont Yankee) and is currently dismantling the Crystal River 3 PWR by implementing an innovative segmentation solution.

This experience could be relevant for upcoming D&D operations at Fukushima-Daiichi.

Vermont Yankee (620 MWe BWR) – RV / RVI

The accelerated dismantling started immediately after the used nuclear fuel was offloaded and transferred to dry storage. Orano completed the segmentation, packaging, and disposal of the RV and RVI in less than four years.

Circular Saw with Custom Clamp & Feed System
Orano deployed field-proven segmentation systems and robust mechanical and thermal cutting technology tailored to the complex BWR components' geometrical constraints. The steam dryer was segmented in air without grouting, which was a first for a BWR in the U.S.

Orano MP197HB Transport Cask
Orano repurposed and licensed used fuel transportation and dry storage systems to package, transport, store, and dispose of reactor irradiated materials. The increased package payload of the Orano TN MP197HB transport cask reduced the number of low-level waste (LLW) packages to 38 for the entire Reactor Vessel and Internals.

Crystal River 3 (860 MWe PWR) – RV / RVI / Reactor Coolant System

In October 2020, NorthStar Group Services and Orano partnered to take over the plant license and operations from the utility Duke Energy, to perform the full dismantlement of the Crystal River Unit 3 Nuclear Power Plant.

Loaded RWC liner ready for packaging
Orano is implementing its patented “Optimized Segmentation” solution, consisting of using the RV to receive the RVI segments from which the Greater- Than-Class-C (GTCC) components were extracted and packaged in two Orano TN NUHOMS Rad Waste Containers (RWC) for onsite storage. The non-GTCC internals components are consolidated and encapsulated within the RV and the resulting monolith is segmented and conditioned in three custom individual packages for off-site transportation and disposal. Orano innovative “Optimized Segmentation” and packaging plan removes and packages the entire RV and RVI components in a total of 6 containers versus an average of 50-80 packages for the traditional approach of full segmentation.

Conclusion

To pursue the full-fledged fuel debris retrieval at Fukushima Daiichi in the decade to come, the operator TEPCO will have to develop an expertise in the full spectrum of dismantling activities, combining Reactor D&D and Fuel Cycle D&D, integrating continuous improvement process in its methods.

Building on proven technologies from past experience and extensive lessons learned, Orano continuously innovates to expand its toolbox and solutions offering to resolve the industry’s challenges with uncompromised safety performance, and is ready to support the Fukushima Daiichi cleanup and dismantling efforts.

NDF Poster (view larger version)

RESOURCES

Vermont Yankee decommissioning

Crystal River 3 decommissioning

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