Japan looks to nuclear energy to power AI-powered datacenter boom

Shuttered reactor's operator says it's needed - once giant seawall is finished

The president of Japanese energy company Hokkaido Electric Power wants to restart one of its nuclear reactors due to a surge in demand from local datacenters.

Susumu Saito asserted [PDF] the power company was working on compliance and regulation processes necessary to restart the Tomari Number 3 reactor. He called the reactor “indispensable for achieving carbon neutrality,” a goal the company has by 2050.

Radiation software SNAFU

Hokkaido Electric Company reported last week that it had identified an issue with software updates for its radioactive gas waste measuring equipment at the Tomari Nuclear Power Plant.

The update, applied in December 2023, failed to appropriately reflect necessary corrections in measurements for iodine and total particulate matter. The error was discovered last Wednesday during routine checks.

The company noted reported emissions since December 2023 had been below the detection limit, meaning no revisions to reported values are necessary.

“We will investigate the cause of this incident and strive to prevent it from recurring,” said the company.

“There is no impact of radiation on the surrounding area as a result of this incident,” it added.

Saito referred to Japan’s other energy sources as “poor,” citing the stability of fuel supply and long-term prices as challenges.

“Nuclear power generation, which is stable and does not emit CO₂ during power generation, is important,” extolled the president.

“We will make all-out efforts to restart operations as soon as possible, based on the premise of ensuring safety,” he added.

Tomari Number 3 was taken offline in May 2012 amid a nationwide shutdown of commercial reactors following the 2011 Fukushima disaster. Since then, some Japanese reactors have resumed operation as risk assessments and safety upgrades have been carried out.

One measure being undertaken at the Tomari plant is the construction of a 19-meter seawall made of concrete and cement-improved soil. Documents [PDF] from Hokkaido Electric Power explain the wall is designed to handle the combination of an earthquake-caused tsunami and a landslide. A fault does lie on the Sea of Japan side of Hokkaido that could cause such an earthquake.

Saito detailed the 180 billion yen ($1.16 billion) construction project should be completed within three years from the start of construction, but that the company was looking at various measures to shorten the process.

“We believe that the critical path for restarting operations will be the installation of seawalls,” said Saito.

Japan has several major up and coming semiconductor, AI and datacenter projects. Japanese chip upstart Rapidus has scheduled a 2 nm wafer fab to come online in 2027 and Softbank is working on a substantial data center project.

Companies like Tenstorrent and ServiceNow are also investing in the nation and opening or have opened offices there. ServiceNow confirmed to The Register its committed to spending $2 billion over the next several years in Japan, which includes investments in AI and data centers.

And prime minister Shigeru Ishiba has pledged over ¥10 trillion ($6.5 billion) in support for his Japan’s AI and semiconductor industries by fiscal year 2030.

Saito is right – all of these endeavors will require energy, more than is currently available.

Japan’s turn toward nuclear follows global trends, as does Hokkaido Electric Company’s strategy to rely on already existing nuclear infrastructure.

In September, Microsoft and Three Mile Island owner Constellation Energy entered a 20 year power purchase agreement on the site’s Unit Number 1 as to power the software giant’s AI endeavors.

Unlike Unit 2, which was the site of a 1979 nuclear accident, Three Mile Island Unit 1 was shut down in 2019 for economic reasons.

Google, Oracle, and Amazon have also explored nuclear energy to power their server farms. ®