Document: NUREG-0800
Document ID: 67e3fd64-e6a4-4522-b90f-4184c2f5b357
Document Type: srp
Title: FUNCTIONAL DESIGN OF CONTROL ROD DRIVE SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070540139.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.6
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Content:
itional operating modes to ensure that there can be no adverse impacts on the essential system function. The reviewer should ensure that systems not relied on for safe shutdown cannot impair essential or passive component functions. Where two or more reactivity systems are used, the reviewer evaluates the combined functional performance under accident conditions. 3. For plants containing control rod drive cooling systems (e.g., using air or water as coolant), the reviewer examines descriptions and drawings to determine that the systems meet the design requirements. The SAR should delineate essential equipment. The reviewer of transient and accident analyses confirms by failure modes and effects analysis that the cooling system is capable of maintaining the CRDS temperature below the applicant’s maximum temperature criterion. The review performed under SRP Section 7.2 confirms that there are sufficient instrumentation and controls available so that the reactor operator in the control room can monitor the CRDS conditions, including the more significant parameters such as coolant flow, temperature, pressure, and stator temperature. 4. Reviewers examine the functional tests of the CRDS related to rod insertion and withdrawal and scram operation and time. The reviewers check the elements of the test program to ensure that all required thermal-hydraulic conditions have been included for all postulated operating conditions. The test program should include experimental verification of system operation where a single failure has been assumed (e.g., accumulator leakage for hydraulic CRDS and stuck rod operation). The reviewers ensure that the system requirements (such as required scram times) are clearly identified and are consistent with the system requirements in the technical specifications and SRP Sections 14 and 15. 5. The reactivity control systems are evaluated to verify that redundant reactivity control systems are not vulnerable to common mode failures. The review