DC Cook Turbine Components

UniTech Services Group Decontaminates 1.6 million lbs. of D.C. Cook Turbine Components Off-Site

Summary

Utilizing the Mississippi, Ohio, and Tennessee navigable river systems,
the Donald C. Cook Nuclear Plant (D.C. Cook) turbine components were shipped by barge, all the way from Michigan to Oak Ridge, TN. UniTech’s Oak Ridge Service Center (ORSC) then decontaminated and radiologically surveyed 1.6 million lbs. of turbine components for unrestricted release. Ultimately, ORSC segmented and recycled these unique metal pieces for final disposition.

Following D.C. Cook Nuclear Generating Station’s fall 2016 outage, UniTech’s ORSC sorted and processed 145,020 lbs. of total material; 85 percent of D.C. Cook’s waste qualified for BSFR disposal. By processing waste for BSFR disposal rather than Low-Level Radioactive Waste (LLRW) disposal, UniTech was able to achieve total waste cost savings close to 40 percent for D.C. Cook. For all DAW-sorted materials in the D.C. Cook project, UniTech achieved a composite price 40 percent lower than typical radwaste disposal rates.

 

Ultimately, the project saved D.C. Cook $2.2 million.

The Challenge

When the Donald C. Cook Nuclear Plant (D.C. Cook) in Lake Township, MI replaced its turbines and corresponding outer casings — which were close to 91 meters in length — disposing of the obsolete turbines demanded a unique but crucial decontamination process.

The major hurdle was determining a feasible method of transporting 687,192-kilograms of turbine components to UniTech’s Oak Ridge, TN service center, thus eliminating the typical utility planning required before on-site turbine decontamination can commence.

The Solution: Shipment

D.C. Cook’s large turbine components were too heavy for long-distance trucking and took up considerable space, but required shipment to UniTech’s Oak Ridge Service Center for off-site processing, decontamination, and final disposition.

Barnhart Crane & Rigging partnered with UniTech and D.C. Cook, shipping turbine components by barge to the newly reopened Oak Ridge barge access area via the Mississippi, Ohio, and Tennessee navigable river systems.

Turbine components were welded to the barge for continuous stability throughout travel. The barge departed from St. Joseph, MI on Sunday, Sept. 10, 2017 and arrived at the Oak Ridge barge area in the early morning hours on Wednesday, Sept. 27 after seventeen and a half days in transit.

The Solution: Receiving

Crews spent the ensuing two days draining the barge water, breaking welds, and setting up cranes for land transportation. It took two full days to unload and stage all six turbine casings from the barge and prepare for trucking to UniTech’s Oak Ridge Service Center. The barge was free released, and departed on Oct. 1. Over the next two days, upper turbine casings were trekked to UniTech’s facility, just five kilometers away, at a cautious pace of 1.6 kilometers per hour, not including the movement of powerlines. Inner casings were received, decontaminated, and cut for recycling within a 72-hour timespan, completed by 2:30 a.m. on Oct. 5.

Shipment of the lower casing components from the dock to UniTech’s Oak Ridge Service Center was delayed when removal of blade carriers posed a risk of crane shock. Delay in shipment to the service center also caused the project to run into fall outage season, a high-volume stretch of time for UniTech’s Oak Ridge facility, which necessitated special off-site storage considerations. Processing of lower casings began on Oct. 10 and finished on Nov. 15.

The Solution: Processing

Once received at the Oak Ridge facility, UniTech processed a total of six casings:

Description Qty Length (m) Width (m) Height (m) Mass (kg)
Inner Casing A – Upper Half 1 9,347 5.004 3.607 70,306.817
Inner Casing B –Upper Half 1 9,347 5.004 3.607 70,306.817
Inner Casing B –Upper Half 1 9,347 5.004 3.607 70,306.817
Lower Casing A w/ Blade Carrier & Shipping Frame 1 9,347 6.299 4.572 158,757.33
Lower Casing B w/ Blade Carrier & Shipping Frame 1 9,347 6.299 4.572 158,757.33
Lower Casing C w/ Blade Carrier & Shipping Frame 1 9,347 6.299 4.572 158,757.33

 

For the D.C. Cook turbine decontamination project, UniTech utilized both standard and specialized monitoring processes.

A unique Gamma Spectroscopy process was utilized to verify decontamination of inaccessible areas, and used as a basis of validation for free release survey documentary.

Within 48 days, 687,192 kilograms of turbine components were processed and invoiced for services. Zero percent of material was disposed as low-level radioactive waste (LLRW); 659,977 kilograms of material (97 percent) was recycled during final disposition; and 20,412 kilograms (3 percent) of material was free released to a Tennessee-approved low-level contamination landfill.

Segmentation was very important to this project in particular, with nearly all materials being prepped for recycling.

The Results

 

With numbers confirmed by D.C. Cook, UniTech estimates that completing the project offsite amounted to $2.2 million in savings for the utility. This figure was calculated based on industry rates for the contractors, training, and handling needed for on-site decontamination, as well as comparison of direct disposal (recycling) versus landfill disposal.

Often, when decontamination is completed on-site, materials are sent to landfills rather than recycled. Off-site disposition proved to be the most cost-effective method for D.C. Cook, while minimizing the utility’s responsibility for the materials and optimizing the amount of materials that could be recycled.

DC Cook Turbine Components 2

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