The Department of Energy’s oversight of contractors building the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington state is improving, according a recent review by DOE’s Office of Enterprise Assessments (EA).
In a separate report, the DOE oversight office gave WTP prime contractor Bechtel National a clean review for recent development of the plant’s Low-Activity Waste Facility.
Bechtel intends to start operations at the plant late in 2021, at which point it will begin treating a large portion of 56 million gallons of radioactive and chemical waste stashed in 177 underground tanks at the former plutonium production site.
The plant is expected to cost nearly $17 billion to build, according to a DOE estimate from late 2016. When construction began in 2001 the estimated cost was $12.2 billion.
The Energy Department’s Office of River Protection (ORP) oversees all tank waste operations at Hanford. In one report, EA’s Office of Nuclear Safety and Environmental Assessments said the office’s strategies for overseeing completion, startup testing, and eventual commissioning of crucial parts of the Waste Treatment Plant “are maturing.”
For example: The Office of River Protection does a good job of using an integrated schedule to prioritize and track its oversight of WTP progress, EA said.
During an on-site review in March, EA observed work practices, reviewed records, and interviewed contractor, and ORP officials.
Along with the LAW Facility, other key components overseen by ORP include the Balance of Facilities and Analytical Laboratory.
In March 2017, Bechtel and AECOM formed a joint venture, Waste Treatment Completion Corp. (WTCC), a subcontractor in charge of completing construction of the vitrification plant. Bechtel’s responsibilities including completing the plant design and delivering the needed equipment and material. In particular, EA credited Bechtel for using a computerized maintenance management system to track upkeep.
Major components of the WTP include a Pretreatment Facility, which divides waste into low-activity and high-activity material. There are also facilities to immobilize both types of waste into glass, as well as the Analytical Laboratory for sampling and testing and the Balance of Facilities (BOF), housing support programs.
Construction of the lab and most of the Balance of Facilities building is essentially complete, the report notes.
The Energy Department decided in late 2016 to curtail construction of the High-Level Waste Facility and concentrate on the Low-Activity Waste Facility, and the Effluent Management Facility. This sequence is meant to ensure processing of direct feed of low-activity waste starts by 2022.
Completion of the Pretreatment Facility has been deferred while technical questions are addressed on waste separation and the design life of pretreatment equipment.
Office of Nuclear Safety and Environmental Assessments personnel observed the pouring and placement of concrete at the EMF and said it was satisfied with the manner it was done.
The DOE Office of River Protection is generally doing a good job of ensuring Bechtel and subcontractors are using proper procedures and addressing problems where they come up, the EA report said.
The next big milestone facing ORP and Bechtel will be completion of the entirety of the laboratory, LAW facility and the Balance of Facility, the EA said.
In its report on the LAW Facility, the Office of Enterprise Assessments focused on nuclear safety issues vital to protecting workers and the public. It also reviewed the DOE hazard evaluation. The “EA reviewed the analyzed fire scenarios, including earthquake-induced fires and the potential effects of fire events leading to explosions.”
Although the hazard category of the LAW Facility shows potential for only local radiological consequences, the review looked at potential chemical hazards. “No radiological consequences exceed the offsite Evaluation Guideline for the public” safety-significant threat levels for co-located workers, according to the document.
The Enterprise Assessments office reviewed the facility’s documented safety analysis, the technical safety requirements document as part of its review of the LAW facility. The Office of Enterprise Assessments found no “opportunities for improvement” after a review conducted from November 2017 to May 2018.
The LAW Facility will convert low-activity waste from Hanford tank farms into a glass form. The vitrified glass containers from the LAW plant will go to Hanford’s integrated disposal facility.
