Document: 10 CFR Part 50
Document ID: fb2cf72e-93fc-4a42-9220-12aef4c8fc19
Document Type: cfr
Title: Criticality accident requirements.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.68
Revision Date: 
Chapter: 
Section ID: 50.68
CFR Part: 50
CFR Title: 10

Content:
If no credit for soluble boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel assembly reactivity must not exceed 0.95, at a 95 percent probability, 95 percent confidence level, if flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel assembly reactivity must not exceed 0.95, at a 95 percent probability, 95 percent confidence level, if flooded with borated water, and the k-effective must remain below 1.0 (subcritical), at a 95 percent probability, 95 percent confidence level, if flooded with unborated water. ( 5 ) The quantity of SNM, other than nuclear fuel stored onsite, is less than the quantity necessary for a critical mass. ( 6 ) Radiation monitors are provided in storage and associated handling areas when fuel is present to detect excessive radiation levels and to initiate appropriate safety actions. ( 7 ) The maximum nominal U-235 enrichment of the fresh fuel assemblies is limited to five (5.0) percent by weight. ( 8 ) The FSAR is amended no later than the next update which § 50.71(e) of this part requires, indicating that the licensee has chosen to comply with § 50.68(b) . ( c ) While a spent fuel transportation package approved under Part 71 of this chapter or spent fuel storage cask approved under Part 72 of this chapter is in the spent fuel pool: ( 1 ) The requirements in § 50.68(b) do not apply to the fuel located within that package or cask; and ( 2 ) The requirements in Part 71 or 72 of this chapter , as applicable, and the requirements of the Certificate of Compliance for that package or cask, apply to the fuel within that package or cask. [ 63 FR 63130 , Nov. 12, 1998, as amended at 71 FR 66652 , Nov. 16, 2006]