Iran and heavy water: Five things to know

A debate over a provision tucked deep in the Iran nuclear deal effectively stalled an energy and water spending bill in the Senate this week. 

An amendment to the bill from Sen. Tom Cotton (R-Ark.) looks to block the U.S. from purchasing Iran’s heavy water, a component of nuclear reactors. The U.S. announced it would buy heavy water from the country for the first time last week. 

{mosads}Supporters of the Iran deal say the heavy water purchases make sense if the accord is meant to reduce Iran’s nuclear capacity. Its opponents, though, say the U.S. shouldn’t subsidize the country by buying reactor materials.

Here are five things to know about heavy water and why it became an issue in the Senate this week.

What is heavy water and what’s it used for? 

Heavy water is simply form of water, made of up different, heavier molecules than normal H2O, said James Acton, the co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace.  

Heavy water is naturally occurring, and it has a handful of practical applications. The most troubling of those — especially when it comes to Iran — is its potential for combining with uranium to produce weapons-grade plutonium.

“Iran’s reactor was a particular concern because it was clearly optimized to build weapons-grade plutonium,” Acton said. “That combination of natural uranium and heavy water in a reactor is pretty suspicious from a weapons point of view.”

There are civilian uses for heavy water, as well. Though it’s a component of only a few electricity-generating power plants worldwide — none in the United States — heavy water can fuel the powerful reactors used in nuclear research or to produce the radioactive materials used to treat certain kinds of cancer, for example.  

What does the Iran nuclear deal say about heavy water? 

Under the deal negotiated between Iran, the United States and a team of other nations, Iran had already agreed to remove the core of its heavy water nuclear reactor and fill it with concrete, rendering it incapable of producing a weapon.

But as an extra safeguard, the United States and others insisted Iran would reduce its stores of heavy water as well. Iranian nuclear facilities can still use heavy water, but the country’s excess stock will be drawn down to no more than 130 metric tons to prevent any secret weapon development activities.

To advance that goal, U.S. officials announced last week that it would purchase 32 metric tons of heavy water from Iran for a reported $8.6 million. The country has other potential buyers, as well: Reuters reports that Russia is considering buying 40 metric tons of heavy water from Iran, a move designed to advance the agreement, Acton said, given that Russia has an ample supply of heavy water.

What is the U.S. going to use its heavy water for? 

In a statement, the Department of Energy said it intends to “resell the purchased heavy water to domestic commercial and research buyers,” including the Oak Ridge National Laboratory in Tennessee. 

“This heavy water purchase will help meet market demand in the United States, fulfilling a substantial portion of the United States’ domestic industry and research needs for the year, while also contributing to the Administration’s nuclear nonproliferation efforts,” an agency spokesperson said.

How does Congress feel about this? 

Republican lawmakers slammed the Obama administration’s purchase this week, saying the United States shouldn’t be “subsidizing” Iran’s nuclear program even if it means drawing down the country’s heavy water supply. 

“Iran has an obligation to reduce its heavy water stocks,” Cotton said Thursday.

“The United States has no obligation to help them. We certainly have no obligation to buy their heavy water, and I don’t think the United States taxpayers should subsidize their nuclear program.” 

Rep. Mike Pompeo (R-Kan.) introduced a similar bill in the House on Thursday.

Sen. Bob Corker (R-Tenn.), chairman of the Foreign Relations Committee, said on Thursday he “had some knowledge that developments were occurring” between the U.S. and Iran, but that he’s skeptical of any purchase agreement between the two countries. 

“Should the United States government be a known end-user for Iran’s heavy water? I don’t know, probably not,” he said. “I don’t think we ought to be the built-in end user of their product.”

The White House mostly dismissed those complaints this week, saying Cotton and other Republicans were simply looking to kick up another legislative fight over the Iran. 

“Sen. Cotton is certainly no expert when it comes to heavy water,” White House press secretary Josh Earnest said Wednesday. “I’m confident that he couldn’t differentiate heavy water from sparkling water.”

Cotton, an Army veteran, struck back, tweeting: “”You’re right, I don’t know much about sparkling water. It isn’t served in Army, unlike in your ritzy West Wing.”

What has this done to the appropriations debate? 

Cotton introduced an amendment to the Senate’s energy and water spending bill on Monday preventing the U.S. from buying heavy water in 2017. 

The White House opposed the amendment, and though it wasn’t scheduled for a vote, Democrats said even the threat of it being attached to the spending bill put the package at risk. They refused to end debate on the legislation twice this week. 

“I think this is a subject matter that should be considered,” said Sen. Ben Cardin (D-Md.), the ranking member of the Foreign Affairs Committee, who opposes the Iran deal. 

“My complaint is that it shouldn’t be on this bill. It should be one that has had the thoughtful process of our committee input, and it hasn’t had that.”

Both Republicans and Democrats this week said the fracas threatens the whole appropriations process — Democrats blaming it on Cotton’s amendment and the GOP pinning it on Democrats’ filibuster.

“They couldn’t wait a single week before throwing an obstructionist wrench into the appropriations process they claim to want,” Senate Majority Leader Mitch McConnell (R-Ky.) said Thursday. He queued up another cloture vote on the package when the Senate comes back.   

“I hope they’re not dusting off the old filibuster summer playbook, especially in light of the letter they just sent to me about win-win opportunities and restoring regular order.” 

Earnest on Wednesday rejected Cotton’s amendment as a way of “undermining the effective implementation of this agreement that prevents Iran from obtaining a nuclear weapon.”

Carnegie’s Acton agreed, saying he sees Cotton’s measure as political. 

“Objectively, even if you don’t support the deal, you should support getting heavy water out of Iran. Having the materials that could be useful for plutonium production in Iran seems to me a bad thing,” he said. 

“I get the feeling that Sen. Cotton’s amendment might have more to do with domestic politics than the merits of the sale.”