The contractor that manages the U.S. Department of Energy’s Savannah River Site took appropriate actions upon finding that a solution sample taken at a key processing facility contained a higher level of plutonium than it should have.
The incident, characterized as an anomaly, resulted in no criticality issues, harm to the environment, or danger to workers, according to a Nov. 2 letter from Kevin Dressman, acting director of the DOE Office of Enforcement, to Stuart MacVean, president of Savannah River Nuclear Solutions (SRNS).
The two-page letter is in response to a November 2017 finding at the site’s HB Line, which works in conjunction with H Canyon to process nuclear materials in order to reduce their nuclear threat. During operations, SRNS employees used a cold chemical dilution to mix with the final amounts of plutonium, also known as the heel, that had been processed at H Canyon and was being transferred to HB Line. Mixing the two components is a common practice to flush out the tanks following operations.
However, when SRNS employees took samples of the solution, testing revealed that plutonium quantities were “higher than anticipated” at HB Line, according to the Enforcement office letter.
The Defense Nuclear Facilities Safety Board (DNFSB) referenced the issue at that time in its weekly site report for Savannah River. The report, dated Nov. 17, 2017, said the plutonium solution was being used to flush out processing vessels at H Canyon. The solution was supposed to total less than 250 grams of plutonium but instead had roughly 500 grams, according to the DNFSB report.
Spokeswoman Barbara Smoak said SRNS immediately reported the finding to DOE’s Occurrence Reporting and Processing System (ORPS), and later filed a report on July 23 with the Energy Department’s Noncompliance Tracking System.
Also at the time of the incident, Savannah River Nuclear Solutions stopped all nuclear material transfers and performed a root cause evaluation to determine why sample levels were higher than anticipated. The contractor concluded that a liquid level detector at H Canyon was inexplicably blocked, causing a buildup of material and a higher level of plutonium in the solution sample.
Savannah River Nuclear Solutions reported all of this to the noncompliance system on July 23 of this year. The Office of Enforcement subsequently conducted its fact-finding from July 24-25 to determine how SRNS responded to the anomaly. The office concluded the contractor correctly handled the issue by determining the cause and “rigorously implemented corrective actions that should prevent recurrence,” Dressman wrote in the letter.
He added: “SRNS personnel consistently demonstrated a questioning attitude and persistent determination in identifying the source and extent of the problem. SRNS’s actions and commitment to facility safety, recurrence prevention, and continuous improvement in nuclear safety performance have been extensive and appropriate.”
The Office of Enforcement did not impose any required actions or responses for SRNS.
