What is SEMPRASAFE?
SEMPRASAFE is a joint venture between EnergySolutions and Studsvik to process ion-exchange resins. The process, known as THOR, uses heat to reform resins into a compact, homogeneous, environmentally stable waste form that is known as reformed residue.
What are ion-exchange resins?
Ion-exchange resins are used to purify the water in nuclear power plants. During this process, the resins remove radioactive isotopes from the water and then must be disposed of as radioactive waste.
Have resins or reformed residue ever been disposed in Utah?
Yes. The Clive disposal facility has disposed of Class A resins and reformed residue from utility customers for many years. In 2010, approximately 40,000 ft3 of resins and reformed residue were disposed at Clive.
Isn’t this just a way to process Class B and C waste so you can call it Class A waste?
No. The THOR process has been in use for over 10 years to process resins. Reformed residue from the THOR process has been disposed of at Clive during this time.
But I have read that EnergySolutions will use the process to turn Class B & C radioactive waste into Class A waste. Isn’t that true?
No. Low-level radioactive waste is not classified until it is packaged for disposal. (See 10 CFR 20 Appendix G, III.C.4.). The waste that will be processed using THOR has not yet been classified for disposal. Processed material that is packaged for disposal that meets Class A criteria may be sent to EnergySolutions’ Clive facility.
Is the THOR process used for waste blending?
Yes. Radioactive resins of various concentrations have long been and will continue to be processed using THOR or alternative processes. These processes are often referred to as blending, which is commonly done by radioactive waste processors and generators. Blending is not dilution. Dilution is defined as mixing clean material with radioactive waste.
Why is blending OK?
Virtually all waste – everything from household garbage to radioactive waste – is mixed, or blended prior to or in the process of disposal. Regulations for the disposal of LLW assume that the waste is mixed over time. There simply is nothing uniquely hazardous about blending. What is important is to ensure the final waste form is safely and compliantly disposed.
How much reformed residue is going to be disposed at Clive?
The projected annual volume of reformed residue waste is 40,000 ft3. This represents less than one percent of the total annual volume of waste we receive at Clive.
Some people say that blending allows EnergySolutions to take “hotter” waste. Does that mean EnergySolutions will take higher categories than Class A?
No. Only Class A waste is approved for disposal in Utah. Class B or C low-level radioactive waste will not be sent to Utah. Utah regulators inspect and monitor the waste that is disposed to ensure compliance.
But isn’t it true that disposing of this waste will dramatically increase the radioactivity at the site?
Every shipment disposed at Clive increases the inventory at our facility, and this waste is no different. The increases, however, will not be as high as have been claimed by others. The total radioactivity at the Clive disposal facility is currently less than three percent of the licensed limit. Even with the increase in radioactivity from the additional reformed residue, the site will be below 3% of its licensed limit.
I also read that this will result in almost all of the Class B and C waste coming to Utah. Is that true?
No Class B or C waste will be coming to Utah. Class B and C waste (e.g., irradiated hardware) will continue to be stored or disposed at other licensed facilities capable of accepting Class B and C waste.
If the THOR process reduces waste volume, won’t that make waste go higher than Class A?
It is possible to increase the classification of waste using the THOR process, but only Class A waste will be disposed of at Clive. Waste that is higher than Class A after processing will not be sent to Utah.
What are the benefits of the THOR process?
The resin is processed into a superior waste form that is proven to be highly stable and homogenous, an ideal combination for disposal.
But don’t generators of LLW have to classify the waste before they ship it for processing?
No, the Nuclear Regulatory Commission regulations require that waste be classified when it is packaged for disposal. This is because processing waste can change the waste classification. Some examples of waste processing are:
- Dewatering – removes mass (water)
- Compaction – reduces volume
- Consolidating resins from multiple vessels in one larger disposal container
- Thermal Processing – removes mass and volume
Each of these processes changes mass or volume, which changes the concentration of radioactivity in the waste. That is why waste cannot be classified until the processed material is packaged and ready for disposal. The final burial container must be classified for disposal.
Shouldn’t EnergySolutions have to analyze the disposal of this waste since NRC says it is a unique waste stream?
EnergySolutions did perform an analysis to demonstrate that disposal of processed resins does not adversely impact the performance of the disposal site. The analysis has been submitted to the Utah Division of Radiation Control (DRC) for its review and approval.
Additional SEMPRASAFE Documents:
· SEMPRASAFE presentation (PowerPoint presentation about THOR steam reforming process)
· ES letter to Utah Radiation Control Board - Disposal of Blended Waste (February 14, 2011)
· ES letter to Utah Radiation Control Board - re WCS Analysis (March 14, 2011)
· Letter from Utah Division of Radiation Control - SempraSafe Disposal (December 12, 2011)
If you have additional questions about SEMPRASAFE:
Please e-mail us at: firstname.lastname@example.org