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

[Amber G.]

BWXT's Innovation Campus in Lynchburg, Virginia, has begun fabricating the reactor core for the Project Pele prototype—marking a major milestone toward turning concept into real hardware
Project Pele was launched in 2019 with the objective of designing, building, and demonstrating a prototype mobile nuclear reactor within five years. The initiative is led by the Department of Defense's Strategic Capabilities Office, which is working in collaboration with the US Department of Energy (DOE), the Nuclear Regulatory Commission and the US Army Corps of Engineers, as well as with industry partners.

BWXT Advanced Technologies and X-energy LLC were subsequently selected to develop a final design for a prototype mobile high-temperature gas reactor using high-assay low-enriched uranium (HALEU) tristructural isotropic (TRISO) fuel under the Project Pele initiative. BWXT was contracted in June 2022 to build a prototype 1.5 MWe microreactor. The contractor team also includes critical roles played by Northrop Grumman, Rolls Royce Liberty Works, and Torch Technologies. The fuel for the reactor will be produced at BWXT's facilities using material from the DOE's highly-enriched uranium inventory.

BWXT has now announced the start of work on the reactor core.

[Tanaji]

The Fukushima Daiichi NPP has been evacuated over a tsunami warning due to the Kamachatka peninsula earthquake. I hope this time around they fare better.

[Amber G.]

The Fukushima Daiichi NPP has been evacuated over a tsunami warning due to the Kamachatka peninsula earthquake. I hope this time around they fare better.

Yes, let’s hope they fare better, but some important context for 2011’s Fukushima Daiichi accident is worth revisiting—especially the human impact.

Total deaths from the 2011 Tōhoku Earthquake and Tsunami:

Over 18,000 people died, almost all due to the natural disaster—the 9.0 magnitude undersea earthquake and the tsunami it triggered on March 11, 2011.
These were non-nuclear deaths—caused by flooding, building collapses, fires, and infrastructure failures.

Deaths due to radiation or direct nuclear causes at Fukushima:

According to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and reports from WHO, IAEA, and Japan’s Nuclear Regulation Authority (NRA):


Zero deaths have been attributed to radiation exposure from the accident.

There were no cases of radiation sickness, and even among the workers involved in cleanup, exposure was within controlled occupational limits for the vast majority.

Long-term radiation effects:

Studies like UNSCEAR's 2020 follow-up report and WHO’s assessments have shown no statistically significant increase in cancer rates or other long-term radiation-related health effects in the general population due to the Fukushima accident.
In fact, the stress and dislocation from evacuation have been shown to cause more health issues than radiation ever did.

Radiation dose comparisons:

This led to many memorable discussions—including hundreds of pages on BRF (Bharat Rakshak Forum) where users like Amber G and others discussed radiation dose in relatable units like the Banana Equivalent Dose (BED).
(One banana gives about 0.1 microsieverts due to naturally occurring potassium-40, a radioactive isotope.)

Many parts of the evacuation zone had radiation levels lower than what airline crew receive annually or people living in Ramsar, Iran or some places in Kerala receive naturally.

So, while the reactor failure was serious and led to much-needed reform in nuclear safety and emergency response, it’s important to differentiate between fear and data. The Fukushima accident was a technological failure triggered by a natural disaster, not a nuclear catastrophe in the way many imagine.

--
This is from 2017 for people's reading pleasure- The 322-page "nuclear white paper" is the commission's first since a serious accident at a nuclear plant https://phys.org/news/2017-09-japan-com ... shima.html

[A_Gupta]

This is CCP news.

China achieves thorium-uranium nuclear fuel conversion in molten-salt reactor
https://www.globaltimes.cn/page/202511/1347088.shtml

China has successfully achieved the first-ever thorium to uranium nuclear fuel conversion in a Thorium Molten Salt Reactor (TMSR), and obtained valid experimental data following thorium fuel loading, confirming the technical feasibility of thorium utilization in a molten-salt reactor nuclear energy system, according to the Chinese Academy of Sciences' Shanghai Institute of Applied Physics (SINAP) on Saturday.

The experimental TMSR, which was built by SINAP in collaboration with other Chinese institutions, is currently the only operational molten-salt reactor in the world loaded with thorium fuel. The realization of thorium-uranium conversion marks a milestone in TMSR development, providing core technical support and a feasible solution for China's large-scale development and utilization of thorium resources, and for the future progress of advanced nuclear energy systems.

[Amber G.]

^^^ Relevant also is what we have discussed elsewhere with this news item:
Chicago firm’s thorium nuclear fuel leap & export nod could ‘give new life to US-India 123 Agreement’

Few point (MY TAKE, FWIW):
- China’s lead lies in reactor technology and closed thorium fuel cycle research.
- India’s new path—using ANEEL thorium + HALEU fuel in its existing PHWR fleet—could short-circuit the long three-stage timeline.
-The U.S.–India 123 Agreement gains relevance again: the ANEEL licence is the first practical tech transfer under it in over a decade.

- The shift from a pure state-led model to private-industry participation (CCTE + L&T + NTPC) marks a structural evolution in India’s nuclear ecosystem.

-If demonstration succeeds, India could deploy thorium fuel in power reactors before China’s demo TMSR, though still without a molten-salt system.
( In above. article Goal 100 MW demo by 2035, For India Print article - working with US
- Commercial use in PHWRs before 2032)
(Assuming Public-private with L&T & NTPC, U.S.–India collaboration continues,
, revival of U.S.–India 123 Agreement.. ityadi (may NOT align with Tzar Bomba bomb testing )

[drnayar]

https://interestingengineering.com/ener ... lt-reactor
China’s first-ever thorium fuel conversion paves way for 100MW molten-salt reactor

[Amber G.]

https://interestingengineering.com/ener ... lt-reactor
China’s first-ever thorium fuel conversion paves way for 100MW molten-salt reactor

From Above:

The stated goal is to construct a 100-megawatt demonstration project and have it operational by 2035.

{This in contrast with, as I said, "For India .. working with US
- Commercial use in PHWRs before 2032)}

[Tanaji]

Why is the Chinese reactor (which is an extension of old American design of the 60s) being so applauded when the Indian design is 300 MW?

[Amber G.]

^^^Because China has successfully achieved the first-ever thorium to uranium fuel conversion in a molten-salt reactor (“TMSR”) (This reactor is reportedly the only operational molten‐salt reactor in the world loaded with thorium fuel)

China has moved from research into the thorium-molten salt reactor space, achieved a milestone of thorium → uranium conversion in a TMSR..It is described as part of “4th generation” nuclear energy systems.. that is it uses a high‐temperature molten salt coolant, runs at (effectively) atmospheric pressure (so no high pressure as in many conventional reactors), and has inherent safety features (cool without water, etc)..

India has a long-standing “three-stage” nuclear program laid out (by Homi Bhabha) designed to exploit its thorium resources..(India has progressed in the first stage and is advancing the second stage (Fast Breeder programs to enable the third stage. For example, the PFBR at Kalpakkam is nearing commissioning, which is an essential step toward thorium utilisation. Although the design for a prototype advanced heavy water reactor (AHWR) – which would burn Th/233U or Th/Pu mix – has been around for many years, the actual construction has not yet begun (as of 2025) in a meaningful commercial sense. In terms of reactor designs using molten‐salt or thorium direct conversion, India seems to lag behind China’s molten salt TMSR route.. but it is well understood..India may need to accelerate its path..

My take: Although China remains ahead for molten salt / thorium reactors, India is will be likely catching up via alternate routes (thorium+HALEU in PHWRs). So the “technology readiness gap” may be smaller than some assumed, at least in the fuel domain rather than full reactor deployment.. We will see. (I am quite optimistic).

[Amber G.]

We will see. (I am quite optimistic).

..
I have posts in BRF 25+ years old.. (fun to how they aged..) here is one to see how it does in the future.. (How optimistic I am - )

Key Milestones to Watch
- Amber G. (November 2025 Predictions)
2026 – Parliamentary approval of nuclear-sector amendments.
2027 – Demonstration irradiation of ANEEL fuel in an Indian PHWR.
2030+ – Fleet-wide thorium-fuel integration and possible AHWR prototype start.
2035 – China’s 100 MW TMSR target; comparative benchmark for India.
2047 – India’s stated 100 GW nuclear-capacity goal; thorium expected to be key contributor.

[Tanaji]

I have no idea of what testing is being referred to here. I am doubtful that Pak can do subcritical tests and it doesn’t have a LIF either

https://www.ndtv.com/world-news/pakista ... er-9565014

Everyone is testing as per Trump

[gakakkad]

I don't think porkies can or want to do sophisticated simulations. I doubt they even simmed their own bums themselves.

If they'll test they ll test in whatever configuration they received the bombs from the Chinese or whoever gave it to them .

[A_Gupta]

Via Dawn:

In a recent social media post, Trump had instructed the US Department of War to resume testing nuclear weapons “immediately”. Confusion has surrounded Trump’s order that the US begin testing, particularly if he meant conducting the country’s first nuclear explosion since 1992.

When the matter was brought up during the {CBS '60 minutes'} interview, Trump said: “Well, we have more nuclear weapons than any other country. I think we should do something about denuclearisation. And I did actually discuss that with both Russian President Vladimir Putin and President Xi.

“We have enough nuclear weapons to blow up the world a 150 times. Russia has a lot of nuclear weapons, and China will have a lot,” he said.

At this point, he was interrupted by the interviewer, who asked, “So why do we have to test our nuclear weapons?”

“Well, because you have to see how they work,” replied Trump. “Testing is because Russia announced that they are gonna do a test. If you notice, North Korea is testing constantly, other countries are testing. We are the only country that doesn’t test, I don’t want to be the only country that doesn’t test.”

He was then asked to clarify whether he was saying that the US would start detonating nuclear weapons after more than 30 years.

He replied, “I am saying that we are going to test nuclear weapons like other countries do.”

But the only country that was testing nuclear weapons was North Korea, the interviewer pointed out. Russia and China have not carried out such tests since 1990 and 1996, respectively.

To that, Trump said Russia and China, too, were testing nuclear weapons. “You just don’t know about it.”

When the interviewer pointed out that Russia’s recent test was that of a delivery system for nuclear weapons, which was essentially a missile, Trump asserted: “Russia is testing, and China is testing, but they don’t talk about it.”

He added: “We are an open society. We are different, we talk about it. We have to talk about it. Because, otherwise, you people are going to report. They don’t have reporters who can be writing about it. We do.

“We are gonna test because they test and others test. And certainly North Korea has been testing. Pakistan has been testing. […] But they don’t go and tell you about it. And as powerful as they are — you know it’s a big world, you don’t necessarily know where they are testing. They test way underground where people don’t know exactly what’s happening with the test. You feel a little bit of a vibration.

“They test, and we don’t test. We have to test. And Russia did make a, you know, little bit of a threat the other day when they said they were gonna do certain forms of a different level of testing. But Russia tests, China does test, and we are gonna test also.”

Trump went on to say: “This just doesn’t make sense. You know, you make nuclear weapons and then you don’t test. How are you gonna do that? How are you gonna know if they work? We have to do that.”

[saip]

^That is from 60 minutes. I listened for a few minutes and heard Dr. Trump's claim that China is testing and 'you do not know about it'

[drnayar]

^That is from 60 minutes. I listened for a few minutes and heard Dr. Trump's claim that China is testing and 'you do not know about it'

ah Dr trump paracetamol and autism

[Amber G.]

Don't forget Trump also said in the same 60 Minutes..

“But I stopped, as an example — India does a lotta business with us. They were going to war. They were gonna have a nuclear war with Pakistan. … The Prime Minister of Pakistan stood up the other day and he said, ‘If Donald Trump didn’t get involved, many millions of people would be dead right now.’ That was a bad war he was ready to start. Shot down airplanes all over the place. That really — that was gonna be a bad war. And I told both of them, I said, ‘If you guys don’t work out a deal fast, you’re not gonna do any business with the United States.’ And they do a lotta business with the United States. And they were both great leaders, and they worked out a deal, and they stopped the war. That would’ve been a bad war. It would’ve been a nuclear war.”

Some more clips:viewtopic.php?p=2664033#p2664033