Scientific Basis Inconclusive, and EPA and NRC Disagreement Continues
T-RCED-00-252: Published: Jul 18, 2000. Publicly Released: Jul 18, 2000.
Pursuant to a congressional request, GAO discussed the regulatory standards used to protect the public from the risks of low-level nuclear radiation, focusing on: (1) whether current radiation standards have a well-verified scientific basis; (2) whether the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC) have come closer to agreeing on exposure limits (how much radiation people can be safely exposed to) in the safety standards; and (3) how implementing these standards and limits may affect the costs of nuclear waste cleanup and disposal activities.
GAO noted that: (1) U.S. radiation standards for public protection lack a conclusively verified scientific basis, according to a consensus of recognized scientists; (2) below certain radiation exposure levels, the effects of radiation are unproven, despite many years of research efforts; (3) evidence of these effects is especially lacking at regulated public exposure levels--levels of 100 millirem a year and below from human-generated sources; (4) at these levels, scientists and regulators assume radiation effects according to what is commonly known as the "linear no threshold hypothesis," or model; (5) according to this model, even the smallest radiation exposure carries a cancer risk, and risks double as the exposure doubles; (6) research into low-level radiation effects continues, including studies attempting to statistically correlate natural background radiation levels in the United States and around the world with local cancer rates; (7) lacking conclusive evidence of low-level radiation effects, U.S. regulators have in recent years set sometimes differing exposure limits; (8) in particular, EPA and NRC appear no closer to agreeing on exposure limits today than in 1994; (9) the two agencies continue to favor different policies and regulatory approaches for various nuclear cleanup and waste disposal applications, especially those relating to groundwater protection; (10) the disagreement involves EPA- and NRC-preferred protection levels that are both well below the range where radiation effects have been conclusively verified; (11) in this regard, the disagreement essentially involves policy judgments and has complicated efforts to clean up facilities, as well as planning for the prospective Yucca Mountain, Nevada, high-level waste repository; (12) costs of implementing radiation protection standards at nuclear cleanup and waste disposal facilities vary from site to site; (13) long-term overall costs could be immense, although these costs have not been comprehensively estimated; (14) an indication of the potential costs is that agencies, especially the Department of Energy, expect to fund hundreds of billions of dollars in nuclear cleanup and waste disposal projects over many years in the future; (15) differences in the costs of the EPA and NRC regulatory approaches to radiation protection have not been comprehensively estimated; (16) however, agency analyses indicate that more restrictive radiation standards cost more to implement, as might be expected; and (17) these analyses also generally show accelerating costs to achieve the most restrictive protection levels.