How did the Chicoms get inside Los Alamos National Lab?

 Washington Examiner:

House Republicans are calling on the Biden administration to investigate the Chinese government’s economic espionage efforts at U.S. research labs following a damning report about Beijing’s apparent extensive efforts at the Los Alamos National Laboratory.

The Republicans wrote to “express our serious concerns” about a new report seeming to show decadeslong Chinese government-linked infiltration into New Mexico’s Los Alamos National Laboratory, a U.S. weapons and nuclear research site, “and to learn what steps your offices are taking to protect our critical research from malign talent recruitment programs.”

The Tuesday letter, led by Rep. Michael Waltz (R-FL) and 10 other House Republicans, was addressed to Secretary of Energy Jennifer Granholm and White House Office of Science and Technology Policy Director Arati Prabhakar.

Waltz told the Washington Examiner, “The Chinese Communist Party, particularly under Xi Jinping, explicitly aims to become the dominant world superpower in the next decade, and they aim to do it through technology.” He said the Chinese government is “rapidly passing us in those areas because they are stealing their way to the top — and a key avenue for which they are stealing their way to the top is through our research labs.”

The congressman added that “it’s almost a fait accompli that [the Chinese government] got some of our sensitive technologies” through the communist nation’s efforts at Los Alamos.

The warning was sparked by a September report by Strider Technologies, a private intelligence firm, titled “The Los Alamos Club: How the People’s Republic of China Recruited Leading Scientists from Los Alamos National Laboratory to Advance Its Military Programs.”

The report concluded that at least 162 scientists who had worked at Los Alamos returned to China “to support a variety of domestic research and development programs” between 1987 and 2021, with 15 of the scientists having worked as permanent staff at Los Alamos and, of the 15, 13 having been recruited into “Chinese government talent programs." The investigation found at least 59 of the scientists had been part of China’s Thousand Talents Program or its Youth Thousand Talents Program.

The FBI has repeatedly warned about China’s Thousand Talents economic espionage program, and Sen. Rob Portman (R-OH) released a report in July about how that Chinese effort also targeted the Federal Reserve over many years .
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This sounds crazy.  What benefit was the US supposed to get by letting the Chicoms into a secret laboratory?  I can't think of any.