Document: NUREG-0800
Document ID: 6d9458c8-25fc-47c7-8406-acd4365b1d3c
Document Type: srp
Title: CONTROL ROD DRIVE SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A472.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.4
CFR Part: 
CFR Title: 

Content:
e loadings associated with plant operations that are expected to occur one or more times during the lifetime of the plant and include, but are not limited to, loss of power to all recirculation pumps, tripping of the turbine generator set, isolation of the main condenser, and loss of all offsite power, combined 3.9.4-11 Revision 4 – March 2017 with loadings caused by natural or accident events including water hammer loads for BWRs. The load combinations that are postulated to occur are specified for each of the design and service conditions as defined in Paragraph NB-3113 of the ASME BPV Code. These load combinations are defined in SRP Section 3.9.3 and are part of the review. The design stress limits, including fatigue limits and deformation limits appropriate to the components of the CRDM, are compared to the limits of specified codes, previously designed and successfully operating systems, or the results of scale model and prototype testing programs. 4. The CRDM of a new design or configuration should be subjected to a life cycle test program to determine the ability of the drive components to function during and after normal operation, anticipated operational occurrences, seismic events, and postulated accident conditions over the full range of temperatures, pressures, loadings, and misalignment expected in service. All-important flow, acoustic, and mechanical excitation mechanisms should be present during the testing (see SRP Section 3.9.2 and RG 1.20, Revision 4, for a discussion of potential excitation mechanisms). This may require the presence of RRPs and potentially isolation valves in the life cycle tests. The tests should include functional tests to determine insertion and withdrawal times, latching operation, scram operation and time, system valve operation and scram accumulator leakage for hydraulic CRDS, ability to overcome a stuck rod condition, and wear. Rod travel and number of operational trips and test trips expected during the mechanism