OVER THE past couple of weeks, two of the arguments made against nuclear power by opponents seem to have gotten stronger: that it is too dangerous, and that it is too expensive. Yet it still would be wrong to rule out a near-carbon-free technology that produces a fifth of the country’s electricity.

On Tuesday, the Japanese government announced a new plan to deal with the stricken Fukushima Daiichi nuclear power facility. Though the Fukushima meltdowns occurred more than two years ago, the facility’s operator, Tokyo Electric Power Co. (Tepco), is still struggling to contain the damage. The latest problem to attract alarm has been tons of contaminated water. Some 400 tons of groundwater mixes with tainted coolant inside the reactors every day. From there, much of it seeps into the ocean. On top of that, makeshift storage tanks containing radioactive coolant have started to leak. Last month, about 300 tons escaped from one tank. Last weekend, Tepco admitted that it found high radiation levels around another, and contamination readings spiked Tuesday.

Japan’s government, finally, has decided to step in more forcefully. Its plan is to continually pump extremely cold liquid deep into the ground, freezing the soil and establishing an “ice wall” past which groundwater couldn’t travel. With luck, that would prevent further interaction between the stricken reactors and underground water flows. The government also wants to improve the equipment Tepco is using to filter the water it is collecting. Even if these measures work, the government will still have to clean up melted nuclear fuel inside the plant, an exceptionally difficult task.

Meanwhile, Entergy Corp., a New Orleans-based utility, announced last week that it would shutter the Vermont Yankee nuclear power station next year. Vermont officials had opposed plans to keep the plant open for 20 more years, but the company appeared to be winning that fight. Instead, the company said, the problem is that the plant isn’t economical. Electricity from now-cheap natural gas has been undercutting wholesale electricity prices, making it harder for nuclear facilities to compete.

Given these examples, it would be easy to conclude that nuclear is an aging technology that the country should abandon. We aren’t convinced.

On safety, Fukushima offers lessons about how not to run a power plant; basic design flaws and subsequent mismanagement were responsible for its problems. Sound regulation can address such issues. The U.S. Nuclear Regulatory Commission required precautionary upgrades of all of America’s nuclear facilities following the Fukushima accident. Regulators must stay vigilant. Plants built in the future, meanwhile, will be much safer, utilizing “passive” safety mechanisms that activate without human intervention.

The economics of constructing nuclear plants is a harder problem to work through. Part of the issue is that the marketplace doesn’t value one of nuclear’s greatest attractions: It reliably produces a lot of electricity without producing carbon dioxide emissions. Construction costs for nuclear plants have also been extremely high. It’s possible that, with more rational climate-change policies in place, new and innovative reactor designs could help bring down nuclear energy’s cost. It’s also possible that some other technology could eventually offer nuclear’s reliability and low-emissions profile at a commercial scale, a unique and necessary combination.

Until that’s clearer, the nation must remain open to maintaining and even expanding its fleet of nuclear power plants.