The Energy Department’s Carlsbad Field Office has approved a plan by contractor Nuclear Waste Partnership (NWP) to gradually improve underground air quality at the Waste Isolation Pilot Plant in New Mexico.
The contractor must take small steps because it won’t be ready to meet much tougher underground air quality standards, by the Jan. 17 compliance date, and probably won’t comply until a new ventilation system is online in a couple years. Also, Nuclear Waste Partnership continues to rely on diesel equipment for salt mining and waste operations.
Nuclear Waste Partnership has been wrestling with the issue after two workers in the underground disposal space became sick in September. Underground air quality, along with heat stress, were identified as potential causes. The company temporarily halted transuranic waste disposal for part of October.
The Energy Department granted NWP’s plan for near, medium, and longer-term mitigation efforts with the understanding it will continue collecting data from ongoing air monitoring, according to a Feb. 1 report from the Defense Nuclear Facilities Site Board (DNFSB).
The 2016 American Conference of Governmental Industrial Hygienists created a standard, listed in the Code of Federal Regulations, to reduce time-weighted worker exposure to nitrogen dioxide (NO2) from 3.0 parts per million (ppm) to 0.2 ppm.
Nuclear Waste Partnership plans to gradually reduce the NO2 levels underground until it can meet the updated allowable limit in late 2022, when the site’s new permanent ventilation system should be operating. The new ventilation system is intended to increase airflow to 540,000 cubic feet per minute, more than triple the current rate.
The Nuclear Waste Partnership plan calls for use of portable and auxiliary fans, use of cleaner-burning diesel fuel, and tweaking administrative and engineering controls as necessary. “The long-term plan is to replace selected diesel equipment with all electric or hybrid units,” according to the DNFSB report.