~ ~~~~~~~ENERGYSOLUTIONS ~~~~~~~

November 1, 2018 CD18-0195

Ms. Janine Katanic Chief - Fuel Cycle and Decommissioning Branch U.S. NRC Region IV 1600 East Lamar Boulevard Arlington, Texas 76011-4511

Subject: EnergySolutions Clive Disposal Facility- Radioactive Material License UT 2300249 License Condition 13, Special Nuclear Material

Ms. Katanic:

lbis letter serves as written follow-up notification of a license limit exceedance regarding a Vacuum-Assisted Thermal Desorption (VTD) batch of waste containing Special Nuclear Material (SNM). On October 24, 2018, EnergySolutions received analytical results from General Engineering Laboratories LLC (GEL), which identified Plutoniwn-239 at a concentration in excess of the limit allowed by License Condition 13.A. In accordance with License Condition 13.H, EnergySolutions is required to provide the U.S. Nuclear Regulatory Commission (NRC) Region IV office notification, which was provided via phone and e-mail, within 24 hours if any License Condition applicable to our SNM exemption is violated. EnergySolutions is also required to provide the NRC Region IV office written notification within seven days of the event.

Summary of Events On September 28, 2018, a sample was collected of the processed material from a VTD treatment run of U.S. Department of Energy's Idaho National Laboratory's (INL) waste. VTD is a treatment process designed to thennally remove volatile organic constituents from while heavy metal and radiological contaminants remain (solids). Post-treatment solid material is reduced in volume and mass due to the removal of the organic constituents that are captured in the system as a condensate. Due to the reduction in mass in the solid material, the radiological concentrations increase. EnergySolutions accounts for the potential increase in concentration by peifonning pre-treatment calculations to estimate the concentration increase in the solids. A post-process sample of this waste was obtained on October 2, 2018 and sent to our in-house lab for gamma spectroscopy analysis p1ior to shipment to GEL for analysis. The gamma spectroscopy analysis indicated a concentration for Americium-241 of 3.2 nCi/g, which was significantly higher than anticipated in the pre-treatment calculation. Due to this higher concentration level, laboratory personnel contacted the site Radiation Safety Officer (RSO) and Assistant Radiation Safety Officer (ARSO). The sample was shipped to GEL for radiological and chemical analyses on October 2, 2018. Results for these analyses were completed and reported on October 24, 2018. The GEL analysis indicated a Plutoniwn-239 concentration of

299 South Main Street, 17'h Floor• , 84111 (801) 649-2000 • Fax: (801) 321-0453 • www..com 14.8 nCi/g. At this level, the sample is greater than Class A waste (License Condition 15.A) and in excess of License Condition 13.E. SNM Exemption for Plutonium-239. A pre-treatment analysis was perfotmed on the waste in accordance with License Condition 15.A. This analysis determined that the resulting processed material would be less than the Class A and the SNM Exemption limits if 30% of the total mass was removed as condensate during the VTD process. However, a much greater reduction of mass was experienced due to higher than anticipated volwnes of condensate removal. The actual mass reduction was 54% of the initial waste weight. Due to this reduction, the quantity of radioactivity was now dispersed over a much smaller mass of processed material and therefore concentrated the activity. Once conclusions were made regarding this exceedance, VTD operations for this waste stream were suspended and will not reswne until fin1her evaluation for the treatment of the remaining waste can be made. All batches after this VTD run are being evaluated and are at risk for exceeding License Condition 13.E. SNM Exemption for Plutonium-239. The Utah Division of Waste Management and Radiation Control (DWMRC) was also notified. If you need any additional information, please do not hesitate to contact me by work phone at 801-649-2168, cell phone at 801-739-4592 or via e-mail at [email protected].

Sincerely,

~d~ Thomas A. Brown Radiation Safety Officer

Cc: DWMRC Scott Anderson Don Verbica Harry Felsher, NRC

299 South Main Street. 17'~ Floor • Salt Lake City. Utah 84111 (801) 649-2000 • Fax: (801) 321-0453 • www.energysolutions.com