International Nuclear Watch & Discussion

[ernest]

thanks a lot for the detailed answer.I feel reprocessing will be crucial for Indian needs, so we cannot abandon PHWR based designs. We have limited funds and time, so switching to MSR at a large scale is not feasible. Over time, if a MSR design is successful in USA, it can be brought in to a portion of our reactors through Indian private companies that will enter in this area in coming years.

[Sanatanan]

^^^ Few comments:

Just a recap. India has constructed and is operating a small ouput reactor called KAMINI which uses U233 as fuel. This U233 was produced in India by irradiating Th in FBTR and reproccessing the irradiated Th to garner U2333. This means that even reprocessing the irradiated Th to garner U233 has been developped indigenously.

[Amber G.]

^^^ To add:
The construction and sustained operation of KAMINI using U-233 fuel, produced entirely through indigenous capabilities, constitutes a major technological milestone. The thorium irradiation campaign in FBTR required careful optimization to maximize U-233 yield while managing parasitic reactions and minimizing U-232 formation. Subsequent reprocessing of irradiated thorium involved advanced radiochemical separations under stringent radiological safety conditions, given the intense gamma background associated with U-232 progeny such as Tl-208. The fabrication of U-233-based fuel elements demanded precision in remote handling, shielded fabrication environments, and rigorous criticality safety management. KAMINI's successful operation validates not only India's ability to close the thorium fuel cycle experimentally, but also demonstrates a functional infrastructure for U-233 stewardship — encompassing breeding, reprocessing, fuel fabrication, and reactor physics with proliferation-resistant isotopic characteristics.

[Amber G.]

The man who his graduate advisor Enrico Fermi called “the only true genius"” has passed into history. He was a true giant, advising every President from Truman to Biden, a universal problem solver. We will not see the likes of him.

Richard L. Garwin, a Creator of the Hydrogen Bomb, Dies at 97
(More details in Physics dhaga)

[Amber G.]

Trump's Iran deal pitch:

We inspect, take stuff, blow up whatever we want—but nobody dies.

Iran:

“Sure, and unicorns will enforce it.”

Trump wants Iran deal that lets US ‘blow up’ nuclear sites, ‘whatever we want’

[Vayutuvan]

It is in India's interest that Iran does not get a nuc. This was discussed in BRF at length.

[Amber G.]

Sharing: Argonne’s Virtual Models Pave the Way for Advanced Nuclear Reactors

EMONT, Ill., May 30, 2025 — Digital twins are virtual replicas of real-world systems, offering transformative potential across various fields. At the U.S. Department of Energy’s (DOE) Argonne National Laboratory, researchers have developed digital twin technology to enhance the efficiency, reliability, and safety of nuclear reactors. This technology leverages advanced computer models and artificial intelligence (AI) to predict reactor behavior, aiding operators in making real-time decisions.

According to Rui Hu, an Argonne principal nuclear engineer, this digital twin technology marks a significant advancement in understanding and managing advanced nuclear reactors. It enables rapid and accurate predictions and responses to changes in reactor conditions.

Digital twins allow scientists to monitor and predict the behavior of small modular reactors and microreactors under different conditions. The Argonne team applied their methodology to create digital twins for two types of nuclear reactors: the now-inactive Experimental Breeder Reactor II (EBR-II) and a new type, the generic Fluoride-salt-cooled High-temperature Reactor (gFHR). The EBR-II digital twin served as a test case to validate the simulation models.

The core of this digital twin technology is graph neural networks (GNNs), a type of AI that processes data structured as graphs, representing interconnected components. GNNs excel at recognizing complex patterns and connections, offering powerful insights into systems where relationships are crucial. By preserving the layout of reactor systems and embedding fundamental physics laws, GNN-based digital twins provide a robust and accurate replica of real systems.

The researchers utilized the Argonne Leadership Computing Facility (ALCF), a DOE Office of Science user facility, to train the GNN and perform uncertainty quantification, which involves identifying and reducing uncertainty in models.

GNN-based digital twins are significantly faster than traditional simulations, quickly predicting reactor behavior during various scenarios, such as changes in power output or cooling system performance. They achieve this by training on simulation data from Argonne’s System Analysis Module (SAM), a tool for analyzing advanced nuclear reactors. The trained model can make accurate predictions based on limited real-time sensor data, supporting better planning and decision-making, and potentially reducing maintenance and operating costs.

Additionally, digital twins can continuously monitor reactors to detect anomalies. If unusual behavior is detected, the system can suggest changes to maintain safety and smooth operation.

Argonne’s digital twin technology offers numerous advantages over traditional methods, providing more reliable predictions by understanding how all reactor parts work together. It can be used for emergency planning, informed decision-making, and potentially autonomous reactor operation in the future. This innovation represents a significant step forward in the development and deployment of advanced nuclear reactors, ensuring they operate safely, reliably, and efficiently while reducing costs and extending component life.

This digital twin technology for nuclear reactors, like the one developed at Argonne,also has significant potential applications in India.

As we are exploring SMRs and advanced thorium-based reactors (like the AHWR) (It can help simulate and optimize these next-gen designs before physical deployment.This is especially valuable for thorium reactor development, where real-world operating data is limited)

India has initiated pilot trials of digital twin technology at the TAPS-3&4 reactors in Maharashtra.

[Vayutuvan]

That Argonne article is light on technical details. Is there a link to a paper somewhere on HPC? I will check and get back.

[Amber G.]

Iran’s Khamenei rejects US nuclear deal proposal, vows to keep enriching uranium