WASHINGTON (Reuters) - The Trump administration briefed congressional staff this week on how the White House was considering non-proliferation standards in a potential pact to sell nuclear reactor technology to Saudi Arabia, but did not indicate whether allowing uranium enrichment would be part of any deal, congressional aides said. Non-proliferation advocates worry that allowing Saudi Arabia to enrich fuel in a nuclear power deal could also enable it to one day covertly produce fissile material and set off an arms race with arch-rival Iran that could spread more broadly throughout the Middle East.  Senate Foreign Relations Committee staff members were briefed by State Department and Department of Energy officials in a meeting on Wednesday, the aides said. They learned the administration “is working to develop a position on non-proliferation standards” should they begin talks with Saudi Arabia on a civilian nuclear cooperation pact known as a 123 agreement, a committee aide said.  The administration is still mulling whether any agreement would allow uranium enrichment, the aide said.  The race to build Saudi Arabia’s first nuclear power reactors is heating up among U.S., South Korean, Chinese and Russian companies.  U.S. Energy Secretary Rick Perry visited Saudi Arabia last week, telling Reuters then that new talks between the two allies on a 123 agreement would start soon. An agreement would allow U.S. companies to participate in Saudi Arabia’s civilian nuclear program. Riyadh has said it wants to be self-sufficient in producing nuclear fuel and that it is not interested in diverting nuclear technology to military use. In previous talks, Saudi Arabia has refused to sign an agreement with Washington that would deprive it of enriching uranium. Uranium fuel for reactors is enriched to only about 5 percent, lower than the 90 percent level for fissile material in nuclear bombs. Some senators with proliferation concerns worry the administration is moving too quickly on talks about nuclear plants and enrichment with Saudi without consulting Congress. As required by a 2008 law, the president is required to keep the committees in the House and Senate that deal with foreign relations “fully and currently informed” on any initiative and talks relating to new or amended 123 agreements. “We’re frustrated by the lack of briefings and having to yet again learn about potential foreign policy developments from the press,” a congressional aide said. A day before the senate briefing, a report by Bloomberg citing sources said that the administration may allow uranium enrichment as part of an agreement. The congressional aide said there are concerns that plans for an agreement are only being conducted by a small number of people controlled by the White House. “It also appears that this is policy being driven out of the White House, which makes congressional oversight that much harder,” said the aide. If lawmakers oppose a civilian nuclear deal signed by the president they can try to fight it with legislation or other measures. The Trump administration and the previous Obama administration have pushed for selling nuclear power technology abroad, partly to keep the country competitive with Russia and China in nuclear innovation. A State Department official said the United States and Saudi Arabia have been in talks since 2012 regarding a 123 agreement but declined to comment on the discussions. Energy Department officials did not immediately comment on the briefing. Toshiba-owned Westinghouse is in talks with other U.S.- based companies to form a consortium for a bid in a multibillion-dollar tender for two nuclear reactors in Saudi Arabia. Winning a bid would be a big step for Westinghouse. It went into Chapter 11 bankruptcy this year and abandoned plans to build two advanced AP1000 reactors in the United States. 