10 CFR § 63.331 - Separate standards for protection of groundwater.

---
identifier: "/us/cfr/t10/s63.331"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "10 CFR § 63.331 - Separate standards for protection of groundwater."
title_number: 10
title_name: "Energy"
section_number: "63.331"
section_name: "Separate standards for protection of groundwater."
chapter_name: "NUCLEAR REGULATORY COMMISSION"
part_number: "63"
part_name: "DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Atomic Energy Act of 1954, secs. 51, 53, 62, 63, 65, 81, 161, 182, 183, 223, 234 (42 U.S.C. 2071, 2073, 2092, 2093, 2095, 2111, 2201, 2232, 2233, 2273, 2282); Energy Reorganization Act of 1974, secs. 201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); 42 U.S.C. 2021a; National Environmental Policy Act of 1969 (42 U.S.C. 4332); Nuclear Waste Policy Act of 1982, secs. 114, 117, 121 (42 U.S.C. 10134, 10137, 10141); 44 U.S.C. 3504 note."
regulatory_source: "66 FR 55792, Nov. 2, 2001, unless otherwise noted."
cfr_part: "63"
---


# 63.331 Separate standards for protection of groundwater.

DOE must demonstrate that there is a reasonable expectation that, for 10,000 years of undisturbed performance after disposal, releases of radionuclides from waste in the Yucca Mountain disposal system into the accessible environment will not cause the level of radioactivity in the representative volume of groundwater to exceed the limits in the following Table 1:

Table 1—Limits on Radionuclides in the Representative Volume

| Radionuclide or type of radiation emitted | Limit | Is natural backgroundincluded? |
| --- | --- | --- |
| Combined radium-226 and radium-228 | 5 picocuries per liter | Yes. |
| Gross alpha activity (including radium-226 but excluding radon and uranium) | 15 picocuries per liter | Yes. |
| Combined beta and photon emitting radionuclides | 0.04 mSv (4 mrem) per year to the whole body or any organ, based on drinking 2 liters of water per day from the representative volume | No. |