Storage Facility Features - std3028

DOE-STD-3028-2000

3. No further basis is provided.

4. No further basis is provided.

A.6.6 Quality Assurance

No further basis is provided.

A.7

STORAGE FACILITY FEATURES

A.7.1 Nuclear Criticality Safety

A principal safety consideration for the safe storage of 233U is eliminating the possibility of the

material reaching a configuration that would result in criticality. Criticality avoidance is a prime

priority in safety considerations in the design and operation of a 233U storage facility. In addition

to providing an array that is criticality safe, the packages and facility shall be engineered,

constructed, controlled, and monitored to avoid the occurrence of accidental criticality for all

credible natural phenomena events such as fires, flooding, earthquakes, and tornadoes.

Because criticality safety is considered the dominant safety concern in the design and operation

of a 233U storage facility, the vault area should be designed with consideration of water sources

such as fire sprinklers. Co-existing combustible materials should be minimized or eliminated

from the facility in order to minimize the potential for fires and the need for fire suppression

systems.

A majority of the 233U in inventory consists of mixtures of 233U and 232U or mixtures whose

properties are dominated by the 233U and 232U content. Uranium-233 has different nuclear

criticality properties than the other two SNMs, 235U and 239Pu. Therefore, facilities designed for

235

U and plutonium may not be acceptable for comparable activities involving 233U from a

nuclear criticality safety standpoint and these facilities shall be evaluated to meet the

requirements for criticality safety specified in DOE O 420.1.

The matrix of the 233U-bearing material and/or the sealed inner container provides the first

barrier against spread of contamination; the outer container and the tube vaults provide

additional barriers. The packaging should be designed to maintain mechanical integrity,

including its seal, during normal handling. However, this package is not expected to provide