2025-13-A Notice of Filing and Public Hearing Notice of Filing and Public Hearing Docket/Case Number and Name: 2025-13-A - Application of Chem-Nuclear Systems, LLC, an EnergySolutions Company, for Adjustment in the Levels of Allowable Costs and for Identification of Allowable Costs (Fiscal Year 2025-2026) Why is this Notice Important? • The Public Service Commission ("Commission") determines the allowable costs of Chem-Nuclear Systems, LLC annually. • The Public Service Commission has scheduled a public hearing. • This Notice is for persons interested in Chem-Nuclear Systems, LLC's annual allowable costs proceedings. • The Atlantic Interstate Low-Level Radioactive Waste Compact Implementation Act authorizes and directs the Public Service Commission "to identify allowable costs for operating a regional low-level radioactive waste disposal facility in South Carolina." What are allowable costs? • Allowable costs are "costs to a disposal site operator of operating a regional disposal facility." S.C. Code Ann. Section 48-46-30(1) • Allowable costs "are limited to costs determined by standard accounting practices and regulatory findings to be associated with facility operations." S.C. Code Ann. Section 48-46-30(1) • Allowable costs expressly include the costs of certain specifically identified activities necessary in the operation of a low-level radioactive waste disposal facility and include "any other costs directly associated with disposal operations determined by [the Commission] to be allowable." S.C. Code Ann. Section 48-46-40(B)(3) What is Chem-Nuclear Systems, LLC asking the Commission to approve in this case? • No adjustments for allowable fixed costs, variable labor and non-labor costs, and routine disposal vault costs as actual allowable fixed costs, variable labor and non-labor costs, and routine disposal vault costs are less than the costs identified in Order No. 2025-302. • An adjustment of $15,415 for irregular costs. • Chem-Nuclear Systems, LLC requests the Commission issue an Order: Recognizing the levels of "allowable costs" in Exhibit A for Fiscal Year 2024-2025; Identifying the levels of irregular costs in Exhibit B for Fiscal Year 2024-2025; and Identifying as "allowable costs" costs depicted in Exhibit C for Fiscal Year 2025-2026. • This case was filed according to S.C. Code Ann. Sections 48-46-40(B)(4), et seq. and, this hearing is scheduled according to S.C. Code Ann. Sections 48-46-40(B)(4), et seq. and S.C. Code Ann. Regs. 103-817. A public hearing has been scheduled in this case to begin on Tuesday, April 21, 2026 at 10:00 a.m. at the Public Service Commission, Hearing Room, 101 Executive Center Drive, Columbia, SC 29210. Intervention deadline: Thursday, November 13, 2025 Manner of filing Intervention: Email contact@psc.sc.gov or mail a Petition to Intervene to 101 Executive Center Drive, Suite 100, Columbia, SC 29210. Please include your email address. You must give a copy of your petition to intervene to all Parties in this case. Manner to file Letters of Protest: File Public Comments or Letters of Protest by emailing contact@psc.sc.gov or mail Public Comments or Letters of Protest to 101 Executive Center Drive, Suite 100, Columbia, SC 29210. For questions regarding this filing, contact the Office of Regulatory Staff at 1-800-922-1531, the South Carolina Department of Consumer Affairs at 1-800-922-1594, Chem-Nuclear Systems, LLC at 1-803-771-8900, or for public information on this filing, contact the Public Service Commission at 1-803-896-5100. 10/3/2025 GRR ACCEPTED FOR PROCESSING - 2025 October 3 9:11 AM - SCPSC - 2025-13-A - Page 1 of 1 IPL0281168 Oct 14 2025