NRC probe of NIST reactor fuel failure finds apparent violations

March 21, 2022, 7:02AMNuclear News
The NIST Center for Neutron Research in Gaithersburg, Md. (Photo: NIST)

In the 13 months since a fuel element failure triggered a scram of the research reactor at the National Institute of Standards and Technology’s NIST Center for Neutron Research (NCNR), the event and its causes have been scrutinized by both NIST and the Nuclear Regulatory Commission.

Initial conclusions from an NRC special inspection released on March 16 confirm that while public health and safety was maintained during and after the event, and doses to reactor facility staff were well below regulatory limits, a safety limit was violated when the temperature of the fuel cladding of a single fuel element in the 20-MWt research reactor reached a temperature high enough to partially melt the element.

Root causes of NIST reactor alert point to operator training

October 6, 2021, 3:02PMNuclear News
A rendering of the core of the NBSR, which consists of 30 aluminum-cladded plate-type U3O8 fuel elements with a 17.8-cm gap between elements. (Image: NCNR Technical Working Group, Root Cause Investigation of February 2021 Fuel Failure) (CLICK IMAGE TO ENLARGE)

The National Institute of Standards and Technology (NIST) has submitted two reports and supplemental information to the Nuclear Regulatory Commission after conducting a root cause analysis of the February 2021 fuel failure and resultant alert at the NIST Center for Neutron Research (NCNR) in Gaithersburg, Md. While the 20-MWt NCNR research reactor remains shut down, scuttling the plans of researchers who rely on it as a source of both cold and thermal neutrons, NIST states in an October 4 update that it has requested permission to restart the reactor, contingent upon meeting all 18 corrective actions identified.

NIST reactor remains shut down as NRC investigates radiation release

February 11, 2021, 7:02AMNuclear News

Neutron measurement studies at the NIST Center for Neutron Research (NCNR) are on hold for an investigation of a different sort. On February 9, less than a week after elevated radiation levels were detected as the NCNR research reactor was powered up following a scheduled maintenance outage, the Nuclear Regulatory Commission began an inspection at the facility. According to NIST, the reactor will remain shut down until the cause of the release is corrected.

“The first step will be to develop a plan for safely assessing the condition of the reactor so that the root cause of the elevated radiation levels can be investigated,” NIST announced on February 5. “Once that root cause is determined, NIST will identify and then implement all necessary corrective actions.”