Document: NUREG-0800
Document ID: f03d2c71-27a1-41fd-9362-1e62c6142e13
Document Type: srp
Title: Containment Systems and Severe Accidents (Tier 1)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070653.pdf
Revision Date: 2023-06
Chapter: 14
Section ID: 14.3.11
CFR Part: 
CFR Title: 

Content:
1996 3. CAPACITY AND CAPABILITY - sizing of sources and distribution equipment, Loading - analyses to demonstrate the capacities of the equipment because this is important to accomplishing the safety function. Tier 2 should discuss the analyses. Testing should be included to demonstrate the EDG capacity and capability. These can be based on the Technical Specifications. (NOTE: Margin - in some cases regulatory guidance specifies the need for margin in capacity to allow for future load growth. If it is only for future load growth, ITAAC does not need to check for the additional margin.) Voltage - analyses to demonstrate voltage drop(because this is important to accomplishing the direct safety function). Tier 2 would include the discussion of how the voltage analyses will be performed, i.e., reference to industry standards or company practice as appropriate. Testing should show the EDG voltage and frequency response. This is the same as Technical Specifications. 4. EQUIPMENT PROTECTIVE FEATURES - inclusion should be based on the potential for preventing safety functions and the operating experience. - Equipment short circuit capability and breaker coordination should be included by specifying ITAAC for analyses. The description of the analyses should be in Tier 2. - Similarly, diesel generator protective trips (and bypasses if applicable) should be considered. A bypass example might be LOCA signals which bypass EDG trips, however specifying that in the DD and ITAAC would probably lock a design into this approach and there is the alternative approach of providing coincidence for the trips. The information in Tier 1 should be written to allow for options which can then be described in Tier 2. - If the fire analyses rely on fire caused faults to be cleared, this may need to be treated in the DD and ITAAC. It may be covered by the breaker coordination (see above). 5. SENSING INSTRUMENTATION AND LOGIC - e.g., detection of undervoltage and start and loading the EDG. This