Approval of Replacement Waste Panels 11 and 12 at the Waste Isolation Pilot Plant

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 194</CFR> <DEPDOC>[EPA-HQ-OAR-2024-0309, FRL 12855-01-OAR]</DEPDOC> <SUBJECT>Approval of Replacement Waste Panels 11 and 12 at the Waste Isolation Pilot Plant</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency. <HD SOURCE="HED">ACTION:</HD> Notification of approval. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The U.S. Environmental Protection Agency (EPA, or the Agency) has approved the U.S. Department of Energy's (DOE, or the Department) planned change request to dispose of defense transuranic (TRU) waste in replacement panels 11 and 12 in the Waste Isolation Pilot Plant (WIPP). This decision is based on a thorough review of information submitted by DOE, independent technical analyses, and public comments. EPA found that DOE demonstrated that the use of two replacement waste panels to replace lost waste disposal volume in panels 1, 7, and 9, would provide a reasonable expectation of the WIPP remaining in compliance with the 10,000-year release limits set by the “Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes” at 40 CFR part 191. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This decision is effective immediately. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Docket: All documents in the docket are listed in the <E T="03">www.regulations.gov</E> index. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. EPA has established a docket for this action under docket ID No. [EPA-HQ-OAR-2024-0309]. Publicly available docket materials related to this action ( <E T="03">e.g.,</E> EPA review documents) are available either electronically through <E T="03">www.regulations.gov,</E> on the Agency's WIPP website ( <E T="03">http://www.epa.gov/radiation/wipp</E> ) or in hard copy at the Air and Radiation Docket in EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004. EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744 and the telephone number for the Air and Radiation Docket is (202) 566-1742. In accordance with EPA's regulations at 40 CFR part 2 and in accordance with normal EPA docket procedures, if copies of any docket materials are requested, a reasonable fee may be charged for photocopying. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Joseph Rustick, Radiation Protection Division, Mail Code 6608T, U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; telephone number: 202-343-9682; email address: <E T="03">rustick.joseph@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. What is the WIPP?</FP> <FP SOURCE="FP-2">II. Contents of the Planned Change Request</FP> <FP SOURCE="FP-2">III. What did EPA review?</FP> <FP SOURCE="FP1-2">A. EPA Review Process</FP> <FP SOURCE="FP1-2">B. APPA Peer Review</FP> <FP SOURCE="FP1-2">C. 19 Panel PA</FP> <FP SOURCE="FP1-2">D. 12 Panel PA</FP> <FP SOURCE="FP-2">IV. Public Comments and Responses</FP> <FP SOURCE="FP1-2">A. Question of PCR Significance</FP> <FP SOURCE="FP1-2">B. The Inclusion of Surplus Pu</FP> <FP SOURCE="FP1-2">C. Legacy Wastes</FP> <FP SOURCE="FP1-2">D. Site Characterization Data</FP> <FP SOURCE="FP1-2">E. Panels 13-19 and Related Issues</FP> <FP SOURCE="FP1-2">F. Fracking and Earthquakes</FP> <FP SOURCE="FP-2">V. Determination</FP> </EXTRACT> <HD SOURCE="HD1">Preamble Acronyms and Abbreviations</HD> Several acronyms and terms used to describe components of the WIPP disposal system and performance assessment computer models are included in this preamble. To ease the reading of this preamble and for reference purposes, the following terms are defined here: <EXTRACT> <FP SOURCE="FP-1">APPA Additional Panels Performance Assessment</FP> <FP SOURCE="FP-1">CBFO U.S. Department of Energy Carlsbad Field Office</FP> <FP SOURCE="FP-1">CCA Compliance Certification Application</FP> <FP SOURCE="FP-1">CFR Code of Federal Regulations</FP> <FP SOURCE="FP-1">CRA Compliance Recertification Application</FP> <FP SOURCE="FP-1">DOE U.S. Department of Energy</FP> <FP SOURCE="FP-1">EPA U.S. Environmental Protection Agency</FP> <FP SOURCE="FP-1">LWA Land Withdrawal Act</FP> <FP SOURCE="FP-1">NMED New Mexico Environment Department</FP> <FP SOURCE="FP-1">PA Performance Assessment</FP> <FP SOURCE="FP-1">PCR Planned Change Request</FP> <FP SOURCE="FP-1">Pu Plutonium</FP> <FP SOURCE="FP-1">RPPCR Replacement Panels Planned Change Request</FP> <FP SOURCE="FP-1">TRU Transuranic</FP> <FP SOURCE="FP-1">VOR Volume of Record</FP> <FP SOURCE="FP-1">WIPP Waste Isolation Pilot Plant</FP> </EXTRACT> <HD SOURCE="HD1">I. What is the WIPP?</HD> The Waste Isolation Pilot Plant (WIPP) is a transuranic (TRU) radioactive waste disposal system developed by the U.S. Department of Energy (DOE) that is located near Carlsbad in southeastern New Mexico. TRU radioactive waste is emplaced about 650 meters (2,150 feet) underground in an ancient layer of salt that will eventually “creep,” encapsulate, and isolate the waste from the surrounding environment. The 1992 WIPP Land Withdrawal Act (Pub. L. 102-579) (LWA) limits radioactive waste disposal in the WIPP to TRU radioactive wastes generated by defense-related activities. The WIPP LWA provides EPA with authority to oversee and certify the long-term performance of the WIPP. The WIPP must meet EPA's generic radioactive waste disposal standards at 40 CFR part 191, subparts B and C. These standards limit releases of radioactive materials from disposal systems for radioactive waste and require implementation of measures to provide confidence for compliance with the radionuclide release limits. Additionally, the regulations limit radiation doses to members of the public and protect groundwater resources by establishing maximum concentrations for radionuclides in groundwater. In 1996, the Agency issued the WIPP Compliance Certification Criteria, which are located at 40 CFR part 194, as mandated by the WIPP LWA, section 8(c). DOE submitted the initial WIPP Compliance Certification Application (CCA) in 1996. The Agency then issued a conditional certification decision on May 18, 1998, determining that the WIPP met the standards for radioactive waste disposal, but identified four conditions as part of the approval (63 FR 27354). Since the 1998 certification decision, EPA has conducted ongoing independent technical reviews, recertifications, and inspections of all WIPP activities related to compliance with the Agency's disposal regulations. The WIPP has been recertified four times since the initial certification in 1998, with the most recent recertification decision occurring in 2022. As part of the original design of the WIPP repository in the initial CCA, the underground waste disposal region at the WIPP is divided into ten panels. A panel is a group of rooms mined into the salt, connected by tunnels called drifts. EPA's initial certification of the WIPP and its most recent recertification of the WIPP in 2022 were both based on a planned footprint of ten waste panels (87 FR 26126, May 3, 2022). <HD SOURCE="HD1">II. Contents of the Planned Change Request</HD> On March 14, 2024, EPA received a planned change request (PCR) from DOE per 40 CFR 194.4(b)(3) seeking the Agency's approval to add two replacement waste panels west of the current repository. These two panels, 11 and 12, will be constructed to recover waste disposal volume lost in panels 7 and 9 due to a 2014 radiological release that contaminated the south end of the repository. Additionally, panel 1 was not completely filled due to ground control issues arising from being kept open so long before waste was emplaced. DOE calculated that 1.7 panels of waste volume will be needed to replace this lost volume, rounded up to two panels for construction. DOE also stated that with the addition of the two replacement panels, the WIPP will not exceed the LWA waste disposal volume limit. DOE recently recalculated the volume of waste already emplaced at WIPP by subtracting waste packages and void space from the total volume of waste. With this updated waste volume calculation, referred to as the Volume of Record (VOR), DOE would need to mine additional waste panels to fully accommodate the total authorized waste volume in the LWA. In the March 2024 PCR, DOE used the VOR approach in its analyses to support the new panels. It did not use the VOR approach in the 2019 Compliance Recertification Application (CRA-2019) but DOE notified EPA of its intent to begin using the VOR approach in 2018 and EPA subsequently concluded that the VOR approach should have no effect on DOE's compliance with EPA's regulations in WIPP Performance Assessment (PA) and the only consequence is to increase the total repository volume required for waste disposal at the WIPP beyond the original ten waste panels. EPA's technical review on the VOR can be accessed under docket ID EPA-HQ-OAR-2001-0012-0772. The PCR, which DOE refers to as the Replacement Panels Planned Change Request or RPPCR, contains a PA that DOE conducted to support a demonstration that the repository will continue to meet the numeric release limits in EPA's disposal regulations for the WIPP. As part of the performance assessment, DOE calculated releases based on a repository design of 19 panels, which DOE anticipates will be the ultimate WIPP repository configuration at the time of closure. However, with t ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 35k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━