Document: NUREG-0800
Document ID: efac696f-0049-4b65-b562-4a813c1d817c
Document Type: srp
Title: STANDBY LIQUID CONTROL SYSTEM (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070538.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.3.5
CFR Part: 
CFR Title: 

Content:
d in Generic Letter 85-03 (Reference 7), the "equivalent in control capacity" wording was chosen to allow flexibility in the implementation of the requirement (e.g., the equivalence can be obtained by appropriately adjusting flow rate, boron concentration or boron enrichment). Generic Letter 85-03 also states that the 326 Lpm (86 gpm) and 13 weight percent sodium pentaborate were values used in NEDE-24222, "Assessment of BWR Mitigation of ATWS, Volumes I and II," December 1979, for BWR/4, BWR/5 and BWR/6 plants with a 638-cm (251-in) vessel inside diameter. That different values would be equivalent for smaller plants was recognized in NEDE-24222. The important parameters to consider in establishing equivalence are vessel boron concentration required to achieve shutdown and the time required to achieve that vessel boron concentration. The minimally acceptable system should show an equivalency in these parameters to the 638-cm (251- in) diameter vessels studied in NEDE-24222. Invoking specific requirements concerning "equivalent reactivity control capacity" for the minimum flow capacity and boron content in the SLCS ensures that sufficient boron can be injected at a rate sufficient to bring the reactor from rated power to cold shutdown. By providing automatic initiation (where required), further assurance is provided with respect to the timeliness of injection and thus of the initiation of reactivity control. This ensures that the SLCS can operate in conjunction with other features to mitigate an ATWS and will increase safety by reducing the potential for exceeding fuel, reactor coolant pressure boundary, and containment integrity limits.33 III. REVIEW PROCEDURES 9.3.5-7 DRAFT Rev. 3 - April 1996 The procedures below are used during the construction permit (CP) review to determine that the design criteria and bases and the preliminary design as set forth in the preliminary safety analysis report meet the acceptance criteria given in subsection II of this SRP section.