Sen. Catherine Cortez Masto will meet with Department of Energy officials next week to establish a regular time for getting briefings on how the agency is complying with a promise to remove the secretly shipped plutonium being stored in the state.

"We want regular briefings on the progress," Cortez Masto said in a brief phone interview after visiting the device assembly facility at the Nevada National Security Site where plutonium is being kept.

"We're going to actually sit down with their staff next week and start talking a timeframe for having those regular updates and briefings," she said.

Late last month, Cortez Masto brokered a deal with DOE to begin removing the half metric ton of weapons-grade plutonium by 2021 as well as received assurances from the agency that it would not ship any more plutonium to the state.

DOE also agreed to keep Nevada's congressional delegation abreast of the headway it makes on the project. With the reach of the accord, Energy Secretary Rick Perry invited Cortez Masto and Sen. Jacky Rosen to visit the site. National Nuclear Security Administration chief Lisa Gordon-Hagerty, who oversees the NNSS, also attended the facility tour.

Cortez Masto said that the visit was "informative," and added she "Ieft feeling confident that they have robust and redundant security there to temporarily store it before it is shipped beginning in 2021."

The senator had raised concerns about seismic activity in the vicinity of the NNSS that they feared could lead to a disaster.

DOE's decision to temporarily store plutonium in Nevada was the result of the agency's failure to meet a deadline to complete construction on a South Carolina facility that is meant to repurpose excess plutonium into fuel for nuclear reactors. A federal judge in May ordered that one metric ton of plutonium be removed from the site by 2019.