Compliance and Regulatory Approaches to Nuclear Accidents: How safe is safe enough?

This week’s post was written by Dr. Ken Ferguson, an independent consultant evaluating project risk and risk mitigation related to new nuclear reactor projects. He has a PhD in Nuclear Science and Engineering from Carnegie – Mellon University and a B.S. in Physics from the University of Michigan.

The recent events in Japan underscore the role that natural events, site selection, and site suitability have on the safety of nuclear power reactors. The developed world addresses the concept of nuclear safety as an integrated effect of the specific design proposed for power generation coupled with the specific site for which the nuclear reactor is being deployed. Many years ago, as a young engineer with nuclear engineering degrees, I made a decision to get the full view of nuclear power projects by accepting my first nuclear position as part of a licensing organization. I soon became involved in a rapid learning curve, appreciation, and incorporation of the “…ologies” into my safety and regulatory interfacing duties. Site characterizations regarding hydrology, geology, seismology, and meteorology are examples of critical information that is collected and transmitted in documents to regulatory reviewers. This information also provides key inputs to the duty cycles imposed on nuclear plant systems and components, as well as the related engineering and safety analyses and evaluations that are performed by nuclear design companies and independently by regulatory staff. In the United States, the Nuclear Regulatory Commission (NRC) creates a series of regulatory guides for power plant applicants to utilize in generating and utilizing site suitability and related plant evaluations. Regulations are promulgated regarding acceptance parameters such as radiological exposure limits for the public and workers for normal operations as well as accident scenarios.

Regulators are the referees, not the champions of the nuclear technologies in which they are involved. One key value performed is determining the safety of the reactor designs proposed by others for deployment. An historical, coincident question and challenge is “how safe is safe enough?”  For nuclear accidents, keeping the reactor sufficiently cooled to prevent fuel damage is an overriding concern. Operating plants utilize electrical powered pumps to deliver such cooling.

The recent earthquake and tsunami in Japan is expected to have compliance and regulatory implications for nuclear power plants world wide. The United States NRC, for example, has already become involved in an action for additional seismic risk evaluations of nuclear plants currently in operation. Other related actions can be expected to occur; including updates to the regulatory process and details to assure that a proper level of safety risk is involved in utilizing specific reactor designs at selected locations. Ramifications could involve rulemaking, public hearings, regulatory guide development and reviews, calls for additional analyses and testing, etc. aimed to assess current adequacy or to establish effective enhancement.

Some of the characteristics of the progression of these reviews and implications for the nuclear regulatory process may include the following:

1. Expect the United States NRC and its staff to be out in front regarding such actions and to be a standard for actions and attentions taken globally.
2. There has been recent attention in “Regulatory Harmonizing” globally regarding coordination and effective and proper consistency among countries. Expect future regulatory enhancement directions to ultimately reflect such harmony to an increasing degree.
3. Expect the attention to be focused on operating units (over one hundred in the US, over 400 globally), followed by new large reactors not constructed (perhaps 60 worldwide) and finally new concepts for small reactors, expected to be applied for next year in the United States.
4. Expect this action to include a necessary involvement of the dozens of emerging nations having a serious interest in nuclear power but not yet ordering plants. Many are working through the establishment of a nuclear regulatory structure as part of a supportive national nuclear infrastructure.
5. An interactive involvement of nuclear design companies, utilities, and regulatory staff as changes are drafted and reviewed internally and externally.
6. Effective implementation of finalized changes to any regulatory process must involve an “early and often” interfacing with regulators to assure that the body of work undertaken and documentation delivered achieves the compliance that the regulations and regulators require.

Do you think that these industry and regulatory actions make a nuclear plant “safe enough?” Tell us your thoughts on this matter.