Secretary
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001
Attention: Rulemakings and Adjudication Staff

U.S. DEPARTMENT OF ENERGY COMMENTS ON PROPOSED REGULATIONS AT 10 CFR PART 63

On February 22, 1999, the U. S. Nuclear Regulatory Commission (NRC) published in the Federal Register its proposed licensing criteria, 10 CFR Part 63, for the disposal of spent nuclear fuel and high-level radioactive wastes in a proposed geologic repository at Yucca Mountain, Nevada.  This letter and its attachments transmit the U.S. Department of Energy's (DOE) comments on the proposed 10 CFR Part 63 as well as DOE's responses to the five specific questions posed by the NRC as part of this rulemaking.

DOE strongly endorses NRC's use of risk-informed, performance-based licensing criteria. This approach is consistent with NRC's ongoing emphasis on regulations that give the highest attention to the issues of most importance to protection of public health and safety.  The elimination of subsystem performance objectives and siting criteria found in the generic regulations at 10 CFR Part 60 in favor of overall performance objectives allows both DOE as applicant and NRC as regulator to place emphasis on the key technical issues related to health and safety aspects of repository performance.

The proposed site-specific rule is a major improvement from the generic rule in terms of providing appropriate flexibility for DOE to determine how to best satisfy the established performance criteria and allowing NRC to focus on the results as the primary basis for regulatory decision-making.  Consistent with this observation, DOE is providing comments that would improve several risk-informed, performance-based aspects of the proposed rule.   

One issue of concern to DOE is the treatment of human intrusion.  The proposed rule for human intrusion requires the repository to meet the same performance objectives in the event of human intrusion as are applied to the unintruded repository.  DOE believes that the human intrusion analysis should focus on a qualitative understanding of the resiliency of the repository.  A national decision on a repository should not rest on quantitative compliance using an unrealistic drilling scenario.  Further, a quantitative standard effectively becomes a subsystem requirement, potentially leading to a suboptimal design to meet that requirement.  DOE recommends that the intrusion case be used only to inform a qualitative judgment on the resilience of the repository.

A second concern is with prescribing requirements for the performance confirmation program and the preclosure integrated safety analysis.  DOE believes that prescribing requirements is inconsistent with the overall performance-based approach in the proposed rule.

Another concern, not addressed in the comments, is that further regulatory changes may be needed to ensure that issues closed at the construction authorization stage would not be reopened at the receipt and possession stage absent significant new safety-related information.  Such a change would allow NRC and DOE to keep their focus on the unresolved issues important to public health and safety.  DOE understands that this change would need to be addressed in a subsequent rulemaking on the licensing process.

In conclusion, we would like to reiterate that DOE fully supports the overall intent and philosophy of the proposed 10 CFR Part 63.  DOE believes that the proposed rule would be effective in protecting the health and safety of the public from potential risks associated with a high-level radioactive waste repository at Yucca Mountain, Nevada.

If you have any questions regarding these comments, please contact April Gil of the Yucca Mountain Site Characterization Office staff at (702) 794-1335 or Nancy Slater of the Office of Civilian Radioactive Waste Management at (202) 586-9322.

Lake Barrett, Acting Director
Office of Civilian Radioactive
Waste Management