ML21019A262
| ML21019A262 | |
| Person / Time | |
|---|---|
| Site: | 07007004 |
| Issue date: | 02/23/2021 |
| From: | Jean Trefethen NRC/NMSS/DREFS/ERMB |
| To: | Jessie Quintero NRC/NMSS/DREFS/ERMB |
| Trefethen J | |
| Shared Package | |
| ML21019A270 | List: |
| References | |
| Download: ML21019A262 (4) | |
Text
1 Centrus Energy Corp. Environmental Report Additional Information The purpose of this summary document is to consolidate additional environmental information that was provided by the licensee following requests from the U.S. Nuclear Regulatory Commission (NRC). This information was evaluated and is referenced in the Environmental Assessment (EA) associated with the Centrus Energy Corp.s, (Centrus) High Assay-Low Enriched Uranium (HALEU) license amendment request (LAR).
The NRC provided questions via email on November 10, 2020 (ML21025A313), asking for clarification on information provided in the LAR and Environmental Report (ER). Centrus provided responses during a phone call and via emails (as noted in parentheticals).
Telephone Call Date and Time:
11:00 AM; December 16, 2020 Call
Participants:
Centrus - Kelly Wiehle (Regulatory Manager)
NRC - Jean Trefethen, Monika Coflin, and Yawar Faraz The purpose of the conference call was to clarify Centrus ER for the American Centrifuge Plant (ACP). The ER was submitted as part of Centrus LAR for the 16-centrifuge HALEU Cascade, which Centrus plans to install in Piketon, Ohio.
The primary purpose of the call was to discuss the licensees anticipated 10-year extension LAR, which may be ready for submittal to the NRC around June 1, 2021. The NRC staff considers this to be a reasonable and foreseeable future action; therefore, it will be addressed in the HALEU EA.
Waste Management:
How will waste be managed during the extension? Department of Energy (DOE) will no longer be responsible for waste - is this correct?
o That is the most likely and conservative scenario. There will be tails that may be turned over to DOE; tails will be turned over to DOE but Centrus will store it onsite.
Currently there is no plan for shipment of process tails; DOE may take them to the depleted uranium hexafluoride Conversion Facility on the reservation adjacent to the ACP. This is unlikely since tails will consist of 1 percent enriched uranium hexafluoride. It is expected that DOE will continue to store tails at the Piketon facility until they can be reused for certain beneficial purposes, such as down-blending.
Tails are not considered waste; thus, they are not subject to the requirement for 90-day removal. Not much waste will be generated due to centrifuge activity, even during the 10 year-extended operation.
o (From 1st January 6, 2021 email from K. Wiehle): Based upon the history of the Lead Cascade Request for Disposals and/or shipments of hazardous waste, American Centrifuge Operating, LLCs (ACO) most conservative estimate is one 55-gallon drum of hazardous waste during the HALEU Demonstration Program (3-year period) and two 55-gallon drums of hazardous waste annually during the potential continued 10-year period of operations. These estimates would not cover an unanticipated calamity type situation.
o (From 1st January 6, 2021 email from K. Wiehle): These conservative estimates would keep ACO in the Very Small Quantity Generator (generate < 220 lbs.
hazardous waste per month) category with the Environmental Protection Agency
2 (EPA), though they will continue to follow the guidance of a Large Quantity Generator (generate > 2,200 lbs of hazardous waste per month), much like was done during Lead Cascade operations.
The LAR indicates that licensee does not plan to store hazardous wastes generated on site for more than 90 days. However, if waste required storage on site for more than 90 days for characterization, profiling, or scheduling for treatment or disposal, a Hazardous Waste Facility Permit would be required and requested at the appropriate time (ACO 2020a).
Does Centrus plan to store hazardous waste for more than 90 days and if so, do they have this permit? What is the plan for disposal if not storing on site for longer than 90 days?
o (From December 15, 2020 email from K. Wiehle): There are no plans for Centrus to store hazardous wastes generated on site for more than 90 days, thus we do not have a Hazardous Waste Facility Permit, nor any intentions of applying for one.
We plan to ship any hazardous wastes within 90 days of generation to a licensed hazardous waste treatment, storage, and disposal facility utilizing a properly regulated hazardous waste transporter. We will follow our procedures and the regulations for proper handling and storage, including weekly inspections, of any hazardous wastes that may be generated by Centrus during the HALEU Demonstration.
Employment:
How will this be impacted by the proposed action and the 10-year extension?
o Would increase incrementally and as needed.
Public and Occupational Health and Safety:
What are impacts of storage of additional material (product and tail) and HALEU product storage until Centrus has customers?
o The existing Integrated Safety Analysis (ISA) evaluated nuclear criticality safety; Centrus has looked at the spacing of cylinders for criticality avoidance.
o During Lead Cascade Facility (LCF) operations, radionuclide releases to the air were measured by a continuous vent or estimated in accordance with guidance in Title 40 of the Code of Federal Regulations Part 61, Appendices D and E. Atmospheric dispersion of the releases was modeled, and the consequent public radiation dose was estimated using EPA-approved computer models in accordance with EPA guidance. The calculated public airborne radiation doses were all lower than the anticipated maximum, the EPA standard, and the NRC limit.
For the HALEU Demonstration, is it accurate to say that a similar process would be used to monitor radionuclide releases, and that release modeling has provided calculated public doses lower than the EPA standard and the NRC limit?
o (From December 15, 2020 email from K. Wiehle): It is accurate to say that similar processes to LCF Operations will be used to monitor radionuclide releases from the HALEU Demonstration. Also, release modeling has been completed using CAP88-PC Version 4.1 and verifies public doses will be lower than the EPA standard and the NRC limit.
Please confirm the proximity of the HALEU Demonstration to the nearest member of the public (i.e., permanent residence) is about 2,200 feet (ft) (670 meters (m)).
o (From December 15, 2020 email from K. Wiehle): The nearest member of the public is approximately 2,200 ft (670 m) from the site fence line. However, the distance from the monitored vent to the nearest member of the public will be approximately 3,907 ft (1191 m).
3 What values (calculated and maximally exposed individual (MEI)) should be considered during the 10-year extended operation?
o (From 2nd January 6, 2021 email from K. Wiehle): Based on historical data from the gaseous diffusion plant and Lead Cascade operations, ACO does not expect any person to exceed 500 mrem/yr. Monitored individuals dose data is evaluated as needed to ensure doses stay below the 500 mrem/year administrative limit. This is accomplished with robust Survey, Radiation Work Permits, and As Low As Reasonably Achievable Committee (ALARA) programs. Routine and job specific surveys identify elevated radiation areas and are tracked and trended to detect changes in conditions or the gradual buildup of radioactive material. This is supplemented by fixed area dosimetry. The Radiation Work Permits identify the need for supplementary dosimetry including self-reading dosimeters or electronic dosimetry. Supplementary dosimetry would be required for entry into a High Radiation Area (HRA). However, an HRA is a remote possibility. Alarm levels are set for both dose rate and total integrated dose as necessary. Dose margins are generally set at 80 percent of administrative limits (500 mrem). The ALARA program uses the data from the survey program, personnel dosimetry, and supplementary dosimetry. Individual doses can be tracked via spreadsheets on a daily basis if needed. The ALARA Committee reviews jobs that have higher individual or collective dose concerns. While not anticipated, the ALARA Committee can authorize levels above the 500 mrem/year individual administrative limit. While an ALARA principle is to keep all individual levels low, this is not to be at the expense of a relatively larger collective dose. This may be the case when only a few individuals have the experience performing complicated tasks.
o (From January 13, 2021 email from K. Wiehle): We use our Radiation Protection Program to stay below 500 mrem; however, we do have a contractor ready to perform any special dose analysis for a worker.
Transportation:
How many shipments of feed would be needed for commercial production?
o (From December 15, 2020 email from K. Wiehle): For the 3-year demonstration, one shipment of feed material is expected. Centrus owned material, coming from Framatome in Richland Washington.
Where will product be stored until Centrus has customers?
o X-3001 building evaluated in the ISA When does Centrus anticipate shipping product to a fuel manufacturing facility?
o Not until after the fuel manufacturing facility is made available. Before they can ship, Centrus will need packaging and transportation qualification if the fuel manufacturing facility is located offsite.
o (From January 13, 2021 email from K. Wiehle): The scope of the HALEU Demonstration Program (3-year) does not cover shipping product offsite other than samples. The DOE-owned product will be stored in a safety compliant container within ACOs NRC licensed and regulated facility in Piketon, Ohio. The specifics of this NRC-approved area within the ACO footprint would not be public releasable information but is described in the Security Plan(s).
o Plans for the extended operation of the HALEU cascade remains under negotiations to determine future ownership and liability; therefore, the product under the extended operation will again be stored in a safety compliant container within ACOs NRC licensed and regulated facility in Piketon, Ohio. NRC approval of a future license
4 amendment request for ACOs proposed packaging and transportation plans would be needed before offsite product shipments would be authorized.
How often will that happen?
o Not happening until a fuel manufacturing facility is available.
How many shipments of hazardous waste during demonstration and during the extension are anticipated during a month?
o None during the 3-year HALEU demonstration; for the 10-year extension, it is not certain how waste will be handled. DOE may take ownership of it [not likely]. If not, Centrus will get the appropriate approval to ship hazardous waste.
Reasonably Foreseeable Activities:
Does Centrus plan to construct the ACP as currently licensed for Low Enriched Uranium production, or is this too speculative at this time to know?
o Could be constructed under the current license. However, this is very unlikely.
Is construction of the ACP to produce HALEU being considered, or is this too speculative at this point?
o On the table but not licensed today. This has been raised but not known at this time, too speculative.
Accident Analysis:
Is there a publicly available document that provides a general discussion on accidents?
o There is no general unclassified discussion of the accidents.
Security/Emergency Planning (EP): NRC staff discussed that no EP is required - thresholds are not exceeded under any accident scenario. Worst case accident does not require EP for the 3-year HALEU demonstration as doses are calculated to be below 1.0 rem 2.0 mg soluble uranium intake thresholds. This is not necessarily the case for the 10-year extension - needs to be evaluated.