Document: NUREG-0800
Document ID: b4734a50-4d73-4532-b9ec-2c7890d55a94
Document Type: srp
Title: and are compared by the reviewer with those provided by the applicant.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070364.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.3
CFR Part: 
CFR Title: 

Content:
56 3.9.4-9 DRAFT Rev. 3 - April 1996 The design stress limits, including fatigue limits, and deformation limits as appropriate to the components of the control rod drive mechanism are compared by the reviewer with those of specified codes, previously designed and successfully operating systems, or with the results of scale model and prototype testing programs. 4. The control rod drive mechanisms of a new design or configuration should be subjected to a life cycle test program to determine the ability of the drives to function during and after normal operationing , pressure testing, anticipated operational occurrences , 57 58 59 seismic, and postulated accident conditions over the full range of temperatures, 60 pressures, loadings, and misalignment expected in service. The tests should include functional tests to determine times of rod insertion and withdrawal, 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 operational 61 62 life should be duplicated in the tests. The reviewer checks the elements of the test program to be sure all required parameters have been included and finally reviews the test results to determine acceptability. Excessive wear, malfunction of components, operating times beyond determined limits, scram accumulator leakage, etc., all would be cause for retesting. Exceptions taken by the applicant to any of the accepted codes, standards, or NRC criteria must be identified and the basis clearly justified so that evaluation is possible. Engineering judgment, experience, comparisons with earlier cases and design margins, and consultation with supervisors permit the reviewer to reach a decision on the acceptability of any exceptions posed by the applicant.63 For standard design certification reviews under 10 CFR Part 52, the procedures above