The contractor for the Energy Department’s Waste Isolation Pilot Plant in New Mexico suspended transuranic waste emplacement during the latter part of October while it looked into worker illnesses linked to ventilation.
Waste shipments have resumed, Nuclear Waste Partnership (NWP) spokesman Donavan Mager said by email. Mager did not say how long work had been suspended. The facility’s public database does not show waste receipt or emplacement during the last two weeks of October.
Two workers became ill in September, according to the Defense Nuclear Facilities Safety Board (DNFSB). One got sick while working in WIPP disposal Panel 7, where waste sent to the site is currently being placed underground, the DNFSB said in an Oct. 5 monthly site report, posted on the board’s website Oct. 23.
“Potential causes of his distress included heat stress and underground air quality,” the DNFSB said, adding a second worker subsequently became ill in the vicinity of Panel 7. Elevated levels of nitrous oxides could be a factor in the workers’ illnesses, the DNFSB said.
Mager said the contractor ordered the safety pause after high levels of volatile organic compounds were discovered in WIPP’s above-ground Waste Handling Building. “Low airflow conditions remain a significant underground worker safety challenge” at WIPP, the DNFSB said.
The contractor is implementing corrective measures including increased ventilation in the Waste Handling Building and in the WIPP underground. Additional “scrubbing capabilities” have been added to cut emissions from diesel-powered equipment used underground, which should reduce the risk of people getting sick from fumes, Mager indicated. Chemical monitoring devices have been installed and a team is looking into other ways to enhance air quality, he said.
In the wake of a February 2014 underground radiation release, WIPP drastically reduced airflow levels to prevent the spread of contaminants. Nuclear Waste Partnership is expected soon to award a contract for construction of a new permanent underground ventilation system that should by 2021 increase airflow to 540,000 cubic feet per minute, more than three times the current rate.
A New York firm, the Encorus Group, is already building six giant fans, each weighing 44,000 pounds and standing 20-feet tall, in order to dramatically increase airflow underground. The fans will suck air through a facility to remove salt from the air. This combats salt buildup on air particulate filters, according to the Energy Department.
Rock Fall Not Expected to Stop Waste Emplacement for Long
Separately, there was an apparent rock fall at about 7 p.m. local time Wednesday in the WIPP underground, the Energy Department and its contractor announced Thursday.
Room 6 of Panel 7 was declared off-limits to employees more than two years ago in anticipation of the rock fall, according to WIPP management. Underground workers in Panel 7 reported hearing a loud thud coming from Room 6, where no TRU waste is stored.
All underground work was stopped at the time of the rock fall and all 53 underground staffers exited. No one was injured. “Everyone responded as their training dictated,” said Nuclear Waste Partnership President and Project Manager Bruce Covert in a press release.
Work remains suspended for now. Unless a follow-up inspection by WIPP’s in-house mine rescue team shows underground conditions are unsafe, the waste emplacement pause should not be lengthy, Mager said.
Rock falls are not uncommon in the WIPP underground, DOE Carlsbad Field Office Manager Todd Shrader said in the news release. The waste disposal facility is effectively a salt mine and salt tends to “creep” and will gradually enclose excavated areas. “All the proper precautions and safety measures were in place to protect our employees,” he added.
No dimensions on the size of the apparent rock fall will be available until geotechnical engineers have reviewed data from underground instruments.
