Mike Nartker
WC Monitor
10/31/2014
In the latest hurdle to getting the Idaho Integrated Waste Treatment Unit up and running, startup testing has been on hold for most of this month because of an equipment issue, and it remains to be seen when the testing will resume. Since Oct. 3, the IWTU has been shut down as the Department of Energy and contractor CH2M-WG Idaho have worked to address concerns with the nozzles in a key facility system. Rework of the nozzles has been completed and they are set to be installed by the end of this week, according to CWI spokesman Erik Simpson. “DOE is currently evaluating the schedule for IWTU outage completion and restart” of testing, Simpson said in a written response. The DOE Idaho Operations Office did not respond to requests for comment this week.
The IWTU is intended to treat approximately 900,000 gallons of liquid waste that remains at the Idaho site through a steam reforming process for disposal and to allow for closure of the site’s remaining waste tanks. DOE previously committed to the state of Idaho to have the waste processed by the end of 2012, but in the summer of that year, startup of the IWTU facility was significantly disrupted by what has been described as a “pressure event” that occurred when the facility’s filters became clogged with carbon material during efforts to get it up to its operating temperature. Since then, DOE and CWI have been working at another attempt to startup the facility. Idaho environmental regulators have said that DOE has also informed them that it won’t meet a revised commitment to have all of the waste treated by the end of this year.
Testing at Simulant Phase
Currently, the IWTU startup testing is at the point where a waste simulant would be introduced into the facility. That has been delayed, though, as DOE and CWI have worked to improve operational efficiency of the nozzles in the facility’s Denitration Mineralization Reformer, which is the first of two fluidized beds in the IWTU steam reforming process. According to a DOE occurrence report, the DMR has three nozzles, but only two are used at any given time during normal operations. “During recent testing activities, it was determined the waste feed nozzle ceramic inserts, which are exposed to 640 degree C temperatures and fluidized solids during normal operation, should be replaced with an identical part made from a different material to help prevent erosion and eventual failure of the waste feed nozzle,” the Oct. 6 report states. “IWTU management made the decision to modify the waste feed nozzles by replacing the ceramic insert with an insert made out of Haynes 556 and have the exposed portion of the insert hard faced with stellite to help prevent erosion.”
Subcontractor Snag
According to the report, CWI sent one waste feed nozzle to subcontractor Premier Technologies Inc. in August to complete the modifications. On Oct. 1, though, after the nozzle had been returned and installed at the IWTU, “a fabrication deficiency” was discovered, the report states. “The stellite hard facing was applied by PTI using an unqualified weld procedure. This discovery was made during an internal review of PTI’s processes,” the report states. As a result, modification work on the other two waste feed nozzles was put on hold while a path forward was developed.
CWI is not concerned with PTI’s performance, according to Simpson. “It is important to ensure the nozzle materials selected and the design can accommodate the high temperatures and materials encountered in the DMR. The nozzle fabrication subcontractor held a fact finding to determine the root cause of the problem and has implemented corrective actions to prevent recurrence. Nozzle rework is complete and was performed with oversight from CWI engineering and quality assurance,” he said, adding, “PTI is a small business teaming partner and continues to provide services to the project.”
