Document: NUREG-0800
Document ID: a2d035da-992b-42e8-894f-787a019b437d
Document Type: srp
Title: NUCLEAR DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070410.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.3
CFR Part: 
CFR Title: 

Content:
fuel, thus reducing the release of fission products to the reactor coolant system and possibly the environment. 6. GDC 25 requires that no single malfunction of the reactivity control system can cause violation of acceptable fuel design limits. The nuclear design review includes verification that no single malfunction of the reactivity control system causes the fuel design limits to be exceeded. Meeting the requirements of GDC 25 significantly reduces the possibility that a malfunction in the reactivity control system would result in nuclear fuel damage. 7. GDC 26 requires that two independent reactivity control systems of different design be provided. Review of the nuclear design verifies that two independent reactivity control systems exist, and that one system can reliably control core reactivity during normal power changes and anticipated operational occurrences. The review also verifies that one system can hold the core subcritical under cold conditions. Compliance with GDC 26 provides assurance that core reactivity can be safely controlled and that sufficient negative reactivity exists to maintain the core subcritical under cold conditions, thus minimizing the likelihood of fuel damage and the subsequent release of fission products. 8. GDC 27 requires that the reactivity control systems have a combined capability, in conjunction with poison addition by the emergency core cooling system, of reliably controlling reactivity changes under postulated accident conditions, with appropriate margin for stuck rods. The nuclear design review verifies that the reactivity control systems provide a movable control rod system and a liquid poison system, and that the core has sufficient shutdown margin assuming a stuck rod. Meeting the requirements of DRAFT Rev. 3 - April 1996 4.3-10 GDC 27 provides assurance that the reactivity control system will be designed such that damage to the fuel in the event of an accident will be minimized. 9. GDC 28 requires that the effects of