Senate Environment and Public Works Chairwoman Barbara Boxer is poised to question federal nuclear regulators Wednesday about the status of a crippled reactor in California.

The committee will hear from all five members of the Nuclear Regulatory Commission to discuss general oversight of nuclear safety, but the California Democrat is likely to home in on her home-state plant that's been shut down since Jan. 31.

The NRC panel will appear before the full committee and the Clean Air and Nuclear Safety Subcommittee.

Boxer has repeatedly expressed concern about the status of the San Onofre Nuclear Generating Station, which was shut down as a precautionary measure after a steam generator tube leak on the Unit 3 reactor (E&E Daily, Feb. 9).

Investigators found hundreds of deteriorated tubes in Units 2 and 3, some of which carried radioactive water. In a May 15 letter to then-NRC Chairman Gregory Jaczko, Boxer pointed to concerns about whether design changes to the steam generators contributed to faster tube deterioration. She also asked whether the plant's owner, Southern California Edison, sidestepped a license amendment for those changes.

Boxer called then for regulators to conduct a comprehensive safety review at San Onofre, located near San Clemente.

The Senate panel is also likely to question the agency's ongoing work to implement safety upgrades at the country's 104 operating reactors after the nuclear crisis that engulfed Japan last year.

Boxer is expected to discuss recommendations to prevent a Fukushima Daiichi-like incident in the United States, citing an April report suggesting the NRC use "probabilistic risk assessments" rather than historical experience to learn about potential nuclear accidents. The chairwoman, who requested the study, said the findings put a spotlight on the commission's failure to use the most effective and efficient assessment technology to prevent a potential nuclear disaster (E&ENews PM, May 29).

The committee is also likely to ask about working relationships of NRC members, given the squabbling that preceded the abrupt resignation of Jaczko earlier this year.

Jaczko's colleagues complained to the White House about his management style, but two lawmakers who were his former bosses said Jaczko was being isolated and punished for standing up against the nuclear industry (Greenwire, Aug. 14).

Allison Macfarlane, a former professor and geologist, has since taken the NRC chair and issued a number of important decisions with her colleagues, including the agency's decision to revamp its policy on storing nuclear waste.

Schedule: The hearing will be Wednesday, Sept. 12, at 10 a.m. in 406 Dirksen.

Witnesses: NRC Chairwoman Allison Macfarlane, Republican Commissioner Kristine Svinicki, Republican Commissioner William Ostendorff, Democratic Commissioner William Magwood and Democratic Commissioner George Apostolakis.