More questions on PF-4

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DNFSB: Lab’s analysis is technically inadequate

By John Severance

The Defense Nuclear Facilities Safety Board is keeping tabs on the Department of Energy, NNSA and the Los Alamos National Laboratory when it comes to the structural integrity of the Plutonium Facility (PF-4).

In DNFSB’s latest letter, dated July 18, the board said an ongoing government analysis of the lab’s ability to withstand earthquakes may be flawed.

The board used the term “technically inadequate” in several ways when it described the lab’s own analysis of how well PF-4 would hold up in a strong earthquake.

The letter stated, “Timely action must be taken to fully understand if additional building modifications are required.”

The board’s letter continued, “The 1970’s-era design and construction of the Plutonium Facility lacks the structural ductility and redundancy that would be required by modern building codes in force today. This lack of ductility and redundancy makes the Plutonium Facility susceptible to catastrophic structural failure if subjected to the strong seismic ground motions identified in the most recent probabilistic seismic hazard analysis conducted by NNSA’s contractor.”

The letter said that the analysis identifies ground motions up to five times greater than the original design basis in the frequency band of interest for the Plutonium Facility.

“NNSA and its contractor are currently performing a static nonlinear analysis intended to definitively characterize the Plutonium Facility’s structural response to large earthquake ground motions. The Board is concerned that the ongoing static nonlinear analysis is proceeding without adequate definition and technical justification,” the letter stated.

This latest communication comes on the heels of one sent in June to the NNSA and LANL, identifying deficiencies in Revision 1 of the 2011 Documented Safety Analysis for the Plutonium Facility. The board requested a report and briefing within 30 days addressing the deficiencies.

Last week, Don Cook, the deputy administrator for defense programs for NNSA, responded and said in a letter addressed to DNFSB chairman Peter Winokur that “in order to develop a response that adequately addresses the board’s issues, the National Nuclear Security Administration and LANL need an additional 45 days beyond the requested 30-day timeframe.”

The biggest concern expressed by DNFSB officials surrounded what would happen in the event of a major earthquake.

The board suggested that radiation released could be more than four times stronger than LANL, which is located near a number of fault lines, predicted in a safety analysis it released last year.

Earlier this year, NNSA and LANL had made extensive upgrades to the building.

But apparently that is not enough, according to the DNFSB.

The oversight panel demanded that DOE write a report within 30 days explaining how it is assessing the facility’s vulnerability to a strong quake.

NNSA released the same comment as last week when asked about the DNFSB letter.

“The NNSA considers the safety of the public our highest priority,” the prepared statement from James McConnell, the Assistant Deputy Administrator for Nuclear Safety, Nuclear Operations, and Governance Reform. “We are working with Los Alamos National Laboratory to respond to the DNFSB.  If necessary or prudent, we will take appropriate actions to further improve the safety basis that documents the hazards and specifies the controls to ensure safety at the Plutonium Facility, PF-4, even as ongoing physical improvements continue to improve the overall safety posture of the facility. Regardless of any future improvements, the risk to the public from operations at PF-4 remains very small; the facility is operating well within the safety objectives established by DOE safety policy, and public safety is adequately protected.”