Mitigation guidance

摘要

Cores should be designed to have as low a control blade density as practical to minimize the effective control blade exposure (ECBE) and effective full insertion days (EFIDs). Use multiple rod pattern sequences throughout the fuel cycle to minimize the ECBE/EFID accumulated on fuel channels susceptible to shadow corrosion-induced bow. Limit continuous control intervals to four months or less (approximately 3 GWd/MTU) to manage the channel conditioning on first or second-cycle fuel.