'This is one more add-on to the horrors of what to do with radioactive material that stays hot for centuries upon centuries. Where to put it?

Where to put it? Which is the bane of the nuclear power industry. For example, America’s nuke plants are full of huge open pools of water containing tons of spent nuclear fuel rods. If exposed to open air, spent fuel rods erupt into a sizzling zirconium fire followed by massive radiation bursts of the most toxic material known to humanity. It can upend an entire countryside and force evacuation of major cities.

According to the widely recognized nuclear expert Paul Blanch: “Continual storage in spent fuel pools is the most unsafe thing you could do.” (see- Nuclear Fuel Buried 108 Feet from the Sea, March 19, 2021)

It’s not just Fukushima that rattles the nerves of people who understand the high-risk game of nuclear power. America is loaded with nuclear power plants with open pools of water that hold highly radioactive spent fuel rods.

What to do with it?'

What a f*ing nightmare... this is what awaits in the near future of severe energy scarcity, with most of the nuke plants built next to seas, oceans & rivers to take advantage of the water for cooling purposes. Couple rising water levels with increased frequency of natural disasters and less ability to maintain the electric grid, and these things could start blasting off every other year with no government or corporate body able to access the money and resources to even pretend to clean up (which is impossible anyway, even during the 'best' of times).

The article doesn't mention that since April 2021 TEPCO have had permission from the Japanese govt to 'dump the stored water to the Pacific Ocean over [the] course of 30 years', though I've not been able to find out whether they've started doing this. See:

'Discharge to ocean by dumping

Immediately after the disaster

On 5 April 2011, the operator of the nuclear plant, Tokyo Electric Power Company (TEPCO), discharged 11,500 tons of untreated water into the Pacific Ocean in order to free up storage space for water that is even more radioactive. The untreated water was the least radioactive contaminated among the stored water, but still 100 times the legal limit.[16][17] In May 2011, another 300,000 tons of untreated radioactive water were dumped to free water tanks.[18]

The UNSCEAR report in 2020 determined "direct releases in the first three months amounting to about 10 to 20 PBq [petabecquerel, 1015 Bq] of Iodine-131 and about 3 to 6 PBq of Caesium-137".[3] About 82 percent having flowed into the sea before 8 April 2011.[19]
Government final approval in 2021

Since the 2011 Fukushima Daiichi nuclear disaster, the nuclear plant has accumulated 1.25 million tonnes of waste water, stored in 1,061 tanks on the land of the nuclear plant, as of March 2021.[22] It will run out of land for water tanks by 2022.[22] It has been suggested the government could have solved the problem by allocating more land surrounding the power plant for water tanks, since the surrounding area had been designated as unsuitable for humans. Regardless, the government was reluctant to act.[23][24][25] Mainichi Shimbun criticized the government for showing "no sincerity" in "unilaterally push[ing] through with the logic that there will no longer be enough storage space"[11]

On 13 April 2021, the Cabinet of Prime Minister Suga unanimously approved that TEPCO dump the stored water to the Pacific Ocean over a course of 30 years. The Cabinet asserted the dumped water will be treated and diluted to drinkable standard.[26][27] The idea of dumping had been floated by Japanese experts and officials as early as June 2016.[5]

Treatment of water (2013-)

Water dumped before 2013 was not treated. Water treatment began in March 2013 as "Advanced Liquid Processing System" (ALPS, Japanese: 多核種除去設備 become operable.[5] ALPS was designed to remove radionuclides; however, it cannot remove tritium, an isotope of hydrogen.[6]

The treatment process began by pouring 400 metric tonnes of water everyday into the damaged reactor buildings to cool them from nuclear meltdown. In addition, another 400 metric tonnes of groundwater was seeping into the basements of buildings and became radioactive contaminated each day. Therefore, 800 tonnes of water was pumped out every day and treated for caesium removal and desalination. While half of the water pumped out was reused for cooling the reactors, the remaining 400 tonnes ended up in storage tanks.[28] As of 2020, the resulted contaminated water reduced to 170 metric tonnes per day.[6] 20% of the water had been treated to the required level as of September 2018, according to TEPCO.[29]

Reactions to dumping
Official nuclear science panels

The Japanese expert panel "ALPS subcommittee", set up by Prime Minister Abe, released a report in January 2020 which calculated that discharging all the water to the sea in one year would cause a radiation dose of 0.81 microsieverts to the locals, therefore it is negligible as compared to the Japanese' natural radiation of 2,100 microsieverts per year.[30] Its calculations was endorsed by IAEA.[31]
A South Korean official report in 2020 found the treated water had "no problem in terms of science".[32][33] On 26 April 2021, Korean Nuclear Society published a separate report along the same line.[34][35]

Japanese public

A panel of public policy professors pointed out the lack of research on the harmful effects of tritium. It also criticized the government being insincere on accepting alternative disposal proposals as the proposals were always shelved after "procedural" discussion.[12]

A survey by Asahi Shimbun in December 2020 found, among 2,126 respondents, that 55% of Japanese opposed dumping and 86% worried about international reception.[36]
The Fukushima Fishery Cooperatives was given written promises by TEPCO's CEO Hirose Naomi in 2015 that TEPCO would not dump the water before consulting the fishery industry.[37] The Cooperatives felt bypassed and betrayed by the government's decision.[5]' - https://en.wikipedia.org/wiki/Discharge_of_radioactive_water_of_the_Fukushima_Daiichi_Nuclear_Power_Plant#Discharge_to_ocean_by_dumping

What could possibly go wrong?

Unf*ingbelievable...
I