Document: NUREG-0800
Document ID: f1b42595-bded-40aa-9d0a-68db845fc3e8
Document Type: srp
Title: MAIN STEAM SUPPLY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350073.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.3
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - Auxiliary Systems Branch (ASB) Power Systems Branch (PSB) Secondary - None I. AREAS OF REVIEW The main steam supply system (MSSS) for both boiling water reactor (BWR) and pressurized water reactor (PWR) plants transports steam from the nuclear steam supply system to the power conversion system and various safety-related or non- safety-related auxiliaries. Portions of the MSSS may be used as a part of the heat sink to remove heat from the reactor facility during certain operations and may also be used to supply steam to drive engineered safety feature pumps. The MSSS may also include provisions for secondary system pressure relief in PWR plants. The MSSS for the BWR direct cycle plant extends from the outermost containment isolation valves up to and including the turbine stop valves, and includes con- nected piping of 2-1/2 inches nominal diameter and larger up to and including the first valve that is either normally closed or is capable of automatic closure during all modes of reactor operation. The MSSS for the PWR indirect cycle plant extends from the connections to the secondary sides of the steam generators up to and including the turbine stop valves, and includes the containment isolation valves, safety and relief valves, connected piping of 2-1/2 inches nominal diameter and larger up to and including the first valve that is either normally closed or capable of automatic closure during all modes of operation and the steam line to the auxiliary feedwater pump turbine. The ASB is responsible for the review of the MSSS from the containment up to and including the outermost isolation valve. The PSB is responsible for the review of the remainder of the MSSS. (The turbine stop valve review is included in SRP Section 10.2.) The PSB also determines the adequacy of the design, installation, inspection, and testing of the electrical power supplies for essential components required for proper operation of the MSSS. The design of the MSSS