Information Notice No. 96-70: Year 2000 Effect On Computer System Software


December 24, 1996



All U.S. Nuclear Regulatory Commission licensees, certificate holders, and registrants (hereafter referred to as licensees).


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert addressees to the potential problems their computer systems and software may encounter as a result of the change to the new century. It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid potential problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no specific action nor written response is required.

Description of Circumstances

Earlier this year, the U.S. House of Representatives held hearings on an issue known as the "Year 2000" software problem. These hearings identified that some of the most important computer software used by the Federal government may not work correctly starting in the year 2000, because the software can only use single years or decades in performing calculations; it will not be able to recognize a change to the new century. Many computer systems will potentially fail to recognize this change to a new century and will misread "00" or the year 2000, as 1900, and thus may cause the system to fail or generate faulty data. The NRC, along with several other Federal agencies, is currently examining computer software used to support Agency functions that may be affected. Specific problems have already been identified and will be corrected. In some instances where future dates are used to schedule actions, problems have already occurred -- well before the end of the century.


The Year 2000 issue affects everyone. It will have an impact on State and local governments, NRC licensees, and businesses. The magnitude of the Year 2000 issue poses a challenge to all those potentially affected. Dates are involved in many facets of computer systems and software. Neither industry nor the Federal government has yet identified the scope of the situation.

This issue may affect NRC licensees in many different ways. For example, computer software used to calculate dose or to account for radioactive decay may not recognize the turn of the century, which could lead to incorrectly calculated doses or exposure times for treatment planning. Other examples of software that may be affected include security control, radiation monitoring, technical specification surveillance testing, and accumulated burn-up programs. Also, equipment that licensees have purchased may contain computer software susceptible to the Year 2000 problem. The problem could occur not only in computer software or data that have been acquired from external sources, but also in programs developed by licensees or consultants. For many licensees, this issue may not prove to be a significant health and safety concern. However, to prevent any other potential problems this issue may precipitate, licensees are encouraged to examine their uses of computer systems and software well before the turn of the century. In assessing computer software, licensees may want to consider reviewing those programs that are used to meet licensing requirements or those that have safety significance.

To facilitate the exchange of information among licensees, NRC, and the public, information related to the Year 2000 problem is posted on NRC's World Wide Web server ( under the "News and Information" option. An example of information that has already been posted is contract language developed by the Federal government for acquisition of new information technology to avoid the Year 2000 problem. In addition to the information presented on NRC's homepage, an Internet list server has been established to encourage discussion of Year 2000 issues. To subscribe to this list, Internet e-mail may be sent to with the message: subscribe year-2000 username, where the username is the first and last name of the individual making the request (e.g., John Doe).

Licensees may wish to consider what actions may be appropriate to examine and evaluate their software systems, and whether to designate an individual to monitor the continuing activities in government and industry to determine the extent of potential problems and proposed solutions. Any additional contact regarding the Year 2000 problem between NRC and licensees will be made through the addressee of this information notice, unless a separate point of contact is designated by the licensee. Licensees who wish to designate a separate point of contact should provide the contact name and address, including telephone and fax number and email address if available, to the appropriate technical contact of this information notice. Holders of Title 10 of the Code of Federal Regulations (CFR) Part 50 licenses are requested to provide this information to the appropriate Office of Nuclear Reactor Regulation (NRR) project manager (courtesy copy to the NRR technical contact listed below).

This information notice requires no specific action nor written response. If you have any questions about the information in this notice, please contact the technical contacts listed below or the appropriate regional office.

signed by

Donald A. Cool, Director
Division of Industrial and Medical Nuclear Safety
Office of Nuclear Material Safety and Safeguards

signed by

Thomas T. Martin, Director
Division of Reactor Program Management
Office of Nuclear Reactor Regulation

Technical contacts: Mark A. Sitek, NMSS
(301) 415-6155

Michael Kaltman, NRR
(301) 415-2905

Page Last Reviewed/Updated Wednesday, March 24, 2021