Document: NRC Regulatory Guide
Document ID: c458fb43-5ee6-4e14-a33d-808ec974115a
Document Type: regulatory_guide
Title: Instrument Lines Penetrating Primary Reactor Containment + HISTORY - HISTORY 09/2009 – DG-1225 , Proposed Revision 1 Prior to the issuance of Revision 1, RG 1.11 was entitled "Instrument Lines Penetrating Primary Reactor Containment (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0909/ML090970530.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.11
CFR Part: 
CFR Title: 

Content:
in the control room because without such an indication, a valve may remain closed, thus impairing instrument functions for an excessive period of time. For remotely operable valves, the operator needs sufficient information about the status of the valve and the condition of the line so that he or she can take proper, timely actions. Lines connected to instruments that are part of the protection or safety systems are extensions of those systems and should satisfy the requirements for redundancy, independence, and testability for those systems to ensure that they accomplish their functions. Lines connected only to instruments that are not part of the protection or safety systems do not need to meet the requirements of the protection or safety systems. For these lines, the assurance that isolation can be effected when required may be of greater importance to safety than the capability of the connected instrument function; therefore, more extensive valving may be preferable. DG-1225, Page 4 C. REGULATORY POSITION 1. Instrument lines penetrating the primary containment that are connected to instruments that are part of the protection or safety systems should satisfy the requirements for redundancy, independence, and testability of those systems. 2. Instrument lines penetrating the primary containment that are part of the reactor coolant boundary should be sized or orificed in such a manner as to ensure that the following occurs in the event of any breach of the line outside of the primary containment during normal reactor operation: a. The leakage is reduced to the maximum extent practical consistent with other safety requirements. b. The rate and extent of coolant loss are within the capability of the normal reactor coolant makeup system. c. The integrity and functional performance of the secondary containment air treatment systems will be maintained. d. The potential radiation doses will be substantially below the guidelines of 10 CFR Part 100 and GDC 19. 3. Instrument