40 CFR § 197.14 - What is a reasonable expectation?

---
identifier: "/us/cfr/t40/s197.14"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 197.14 - What is a reasonable expectation?"
title_number: 40
title_name: "Protection of Environment"
section_number: "197.14"
section_name: "What is a reasonable expectation?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "F"
subchapter_name: "RADIATION PROTECTION PROGRAMS"
part_number: "197"
part_name: "PUBLIC HEALTH AND ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR YUCCA MOUNTAIN, NEVADA"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Sec. 801, Pub. L. 102-486, 106 Stat. 2921, 42 U.S.C. 10141 n."
regulatory_source: "66 FR 32132, June 13, 2001, unless otherwise noted."
cfr_part: "197"
---


# 197.14 What is a reasonable expectation?

Reasonable expectation means that NRC is satisfied that compliance will be achieved based upon the full record before it. Characteristics of reasonable expectation include that it:

(a) Requires less than absolute proof because absolute proof is impossible to attain for disposal due to the uncertainty of projecting long-term performance;

(b) Accounts for the inherently greater uncertainties in making long-term projections of the performance of the Yucca Mountain disposal system;

(c) Does not exclude important parameters from assessments and analyses simply because they are difficult to precisely quantify to a high degree of confidence; and

(d) Focuses performance assessments and analyses upon the full range of defensible and reasonable parameter distributions rather than only upon extreme physical situations and parameter values.