Radiation risk underestimated

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DNFSB: If a major earthquake hits, radioactive release could be four times greater than originally projected

Much has been made in the past year on the speculation of how a major earthquake would affect Los Alamos and especially the Plutonium Facility (PF-4).

The Defense Nuclear Facilities Safety Board weighed in on one of those scenarios recently. And the news was not good.

Apparently, the Los Alamos National Laboratory has underestimated the amount of radiation that could leak from the facility as a result of an earthquake, according to the DNFSB.

This is the first paragraph of a letter from DNFSB addressed to NNSA administrator Thomas D’Agostino, dated June 18.

“The Defense Nuclear Facilities Safety Board (Board) has reviewed the approved safety basis for the Plutonium Facility (PF-4) at Los Alamos National Laboratory (LANL) and concludes that for one accident the mitigated dose consequences to the public exceed 100 REM total effective dose equivalent (TEDE), which would require additional safety controls for the facility.

“The Board’s analysis differs from Revision 1 of the 2011 Documented Safety Analysis by LANL that presents a mitigated offsite dose of 23 REM TEDE. A detailed review by the board’s staff identified a number of deficiencies in the technical basis that supports the 2011 DSA, including concerns with the quality review process for documents and analyses.”

With that statement, DNFSB is claiming 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.

The lab’s estimate was just below a Department of Energy “evaluation guideline” of 25 REM TEDE, advisory board chairman Peter Winokur wrote. A finding of more than 25 would require the lab to implement the highest level of safety controls the department can prescribe.

In an interview, Winokur told Project on Government Oversight that the advisory board’s estimate was “not meant to be a realistic assessment” of the impact on people in nearby communities. The potential health effects on actual populations were beyond the scope of the analysis, he said.

Winokur added that radiation risk to workers at the site of a leak is usually higher than the risk to outsiders.

And according to a Nuclear Regulatory Commission fact sheet, exposure to greater than 50 REM has been associated with numerous cancers including leukemia.

The lab referred all questions to the NNSA.

In a prepared statement, “The NNSA considers the safety of the public our highest priority,” said James J. McConnell, NNSA 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.”

Back in February, Donald Cook, the deputy administrator for weapons programs wrote a letter to the DNFSB stating, “Our evaluation of the existing PF-4 facility in 2008 established a Documented Safety Analysis (DSA) for the facility that was compliant with the Department’s Nuclear Safety Rule.

“The DSA concluded that safety measures at PF-4 were reasonable and adequately protected the public under current standards for existing facilities. However, the evaluation highlighted that the facility was not as resilient and its safety systems were not as effective as we would require of a new facility constructed today.

“Therefore, taking the most conservative approach, we concluded that additional analysis and modifications to PF-4 were warranted to minimize the potential for a radiological release following an accident triggered by a rare earthquake and subsequent main-floor fire. Upon analysis, the actual risk to the public was so small, given the rarity of the earthquake and fire event, that NNSA concluded that it was prudent to allow continued operations while we took measures to modernize the facility.”

Lab director Charlie McMillan, last November, said he had the utmost confidence in those upgrades.

“I must stress that PF-4 even without its recent upgrades is among the most robust structures in the region if not the state,” he said. “In the event of a major earthquake, I believe I would rather be in PF-4 than in my own home.”

According to POGO, the board’s recent report is part of its ongoing oversight of safety upgrades at PF-4. The report said that Los Alamos has completed some “near-term compensatory measures” over the past few years to reduce the risk of fires caused by earthquakes. The laboratory has also drawn up a long-term plan for additional upgrades to ventilation and fire suppression systems, the report said.

In his written response, Winokur said the timeline for installing “seismically qualified” ventilation and fire suppression systems “extends to 2020.”

Both the Los Alamos and advisory board radiation leakage projections represent marked improvements from an earthquake and fire safety analysis Los Alamos performed in 2008, according to POGO. That study predicted “a mitigated offsite dose consequence” of more than 2,000 REM TEDE, according to the new advisory board report.

The board also poked holes in LANL’s 2011 safety analysis.

For example, according to POGO, the board said the lab erroneously assumed that walls consisting of “gypsum board panels” — an apparent reference to drywall — would remain intact after an earthquake.

“Inappropriately relying on laboratory walls to perform functions that they are not credited or qualified to perform” potentially underestimates the amount of radiation that would leak, the report said.

The board also found that the lab did not adequately consider the presence of combustible material in the facility. For example, the board said that the basement at the Plutonium Facility houses both combustible material and electrical panels that are not programmed to shut off in the event of an earthquake. Though the two could combine to ignite a fire in the basement, the lab assumed that the risk was “not credible,” the board said.

Additionally, the board, which might undergo budget cuts in the next fiscal year, said glove boxes at the facility feature shielding made of combustible material.

The lab did not fully account for the flammable shielding, the report said.

The board also accused the lab of underestimating the quantity of fine, “respirable” plutonium powder that would be released into the air. The board said the lab based its calculations on “an arbitrary factor” and the resulting estimate “cannot be technically justified.”

The lab considered only one fire breaking out in the aftermath of an earthquake even though PF-4 could be threatened by multiple fires breaking out simultaneously, the board said.

The board said “for one accident the mitigated dose consequences to the public exceed 100 REM total effective does equivalent (TEDE), which would require additional safety controls for the facility.”

In concluding the letter to D’Agostino, the board insisted on the following within 30 days of receipt of the letter.

• NNSA plans for providing a sound and technically justifiable Safety Basis that includes correction of the non-conservative deficiencies identified in the enclosed report.

• Necessary actions to ensure that quality assurance requirements are adequately implemented at LANL for Safety Basis development.

• NNSA actions to ensure Safety Basis review and approval processes are performed with sufficient rigor to prevent technically deficient Safety Bases from being approved.

Mia Steinle of POGO and John Severance contributed to this report.