Daily Rules, Proposed Rules, and Notices of the Federal Government


Draft Regulatory Guide: Issuance, Availability

AGENCY: Nuclear Regulatory Commission.
ACTION: Issuance, Availability of Draft Regulatory Guide (DG)-1178.
FOR FURTHER INFORMATION CONTACT: Khoi H. Nguyen, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone: (301) 251-7453 or

The U.S. Nuclear Regulatory Commission (NRC) has issued for public comment a draft guide in the agency's “Regulatory Guide” series. This series was developed to describe and make available to the public such information as methods that are acceptable to the NRC staff for implementing specific parts of the NRC's regulations, techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the staff needs in its review of applications for permits and licenses.

The draft regulatory guide, entitled, “Instrument Sensing Lines,” is temporarily identified by its task number, DG-1178, which should be mentioned in all related correspondence.This guide describes a method that the staff of the NRC considers acceptable for use in complying with the Commission's regulations with regard to the design and installation of safety-related instrument sensing lines in nuclear power plants. To meet these objectives, the sensing lines must serve a safety-related function to prevent release of reactor coolant as a part of the reactor coolant pressure boundary and provide adequate connection to the reactor coolant system for measuring process variables (e.g., pressure, level, and flow). The term “safety-related” refers to those structures, systems, and components necessary to ensure (1) The integrity of the reactor coolant pressure boundary, (2) the capability to shut down the reactor and maintain it in a safe shutdown condition, or (3) the capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparable to the guideline exposures of Title 10, Part 100 of the Code of Federal Regulations, (10 CFR Part 100), “Reactor Site Criteria.”

II. Further Information

The NRC staff is soliciting comments on DG-1178. Comments may be accompanied by relevant information or supporting data, and should mention DG-1178 in the subject line. Comments submitted in writing or in electronic form will be made available to the public in their entirety through the NRC's Agencywide Documents Access and Management System (ADAMS).Personal information will not be removed from your comments. You may submit comments by any of the following methods:

1.Mail comments to:Rulemaking, Directives, and Editing Branch, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

2.E-mail comments to:

3.Hand-deliver comments to:Rulemaking, Directives, and Editing Branch, Office of Administration, U.S. Nuclear Regulatory Commission, 11555 Rockville Pike, Rockville, Maryland 20852, between 7:30 a.m. and 4:15 p.m. on Federal workdays.

4.Fax comments to:Rulemaking, Directives, and Editing Branch, Office of Administration, U.S. Nuclear Regulatory Commission at (301) 415-5144.

Requests for technical information about DG-1178 may be directed to the NRC Senior Program Manager, Khoi H. Nguyen at (301) 251-7453 or e-mail

Comments would be most helpful if received by February 6, 2009. Comments received after that date will be considered if it is practical to do so, but the NRC is able to ensure consideration only for comments received on or before this date. Although a time limit is given, comments and suggestions in connection with items for inclusion in guides currently being developed or improvements in all published guides are encouraged at any time.

Electronic copies of DG-1178 are available through the NRC's public Web site under Draft Regulatory Guides in the “Regulatory Guides” collection of the NRC's Electronic Reading Room at copies are also available in ADAMS (, under Accession No. ML080510453.

In addition, regulatory guides are available for inspection at the NRC's Public Document Room (PDR), which is located at 11555 Rockville Pike, Rockville, Maryland. The PDR's mailing address is USNRC PDR, Washington, DC 20555-0001. The PDR can also be reached by telephone at (301) 415-4737 or (800) 397-4205, by fax at (301) 415-3548, and by e-mail

Regulatory guides are not copyrighted, and Commission approval is not required to reproduce them.

Dated at Rockville, Maryland, this 1st day of December 2008.

For the Nuclear Regulatory Commission.

Andrea D. Valentin, Chief, Regulatory Guide Development Branch, Division of Engineering, Office of Nuclear Regulatory Research.