Document: NUREG-0800
Document ID: fb538e14-08a0-4d3f-a974-8170cbfe0b5b
Document Type: srp
Title: ASME CODE CLASS 1, 2, AND 3 COMPONENTS,
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340603.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.3
CFR Part: 
CFR Title: 

Content:
motion, activation level, or release rate. The stiffness should be based on structural and hydraulic compliance only, and should consider the effects of temperature. The snubber end fitting clearance and lost motion must be mini- mnized and should be considered when calculating snubber reaction loads and stress which are based on a linear analysis of the system or component. This is especially important in multiple snubber applications where mismatch of end fitting clearance has a greater effect on the load sharing of these snubbers than does the mismatch of activation level or release rate. Equal load sharing of multiple snubber supports should not be assumed if mismatch in end fitting clearance exists. (3) Design Specifications The required structural and mechanical performance of snubbers is determined from the user's system analysis described in (1) and (2). The snubber Design Specification is the instrument provided by the purchaser to the supplier to assure that the requirements are met. The Design Specification should contain (i) the general functional requirements, (ii) operating environ- ment, (iii) applicable codes and standards, (iv) materials of construction and standards for hydraulic fluids and lubricants, (v) environmental, structural, and performance design verification tests, (vi) production unit functional verification tests and certification, (vii) packaging, shipping, handling, and storage requirements, and (viii) description of provisions for attachments and installation. In addition, the snubber manufacturer should be requested to submit his quality assurance and assembly quality control procedures for review and acceptance by the purchaser. (4) Installation and Operability Verification Assurance that all snubbers and properly installed prior to preoperational piping vibration and plant start-up tests should be provided. Visual observation of piping systems and measure- ment of thermal movements during plant start-up tests could verify that