Examples of Contingency Analyses

DOE-STD-3007-93

APPENDIX C, D,... ETC.

OPTIONAL APPENDICES PROVIDING

SUPPLEMENTAL INFORMATION

Other appendices providing supplemental information may be provided at the author's discretion.

EXAMPLE # 1

Contingency analysis for a dry storage cask that is used to store irradiated

PWR or BWR fuel assemblies.

Contingency

No.

Description

Barriers

Flood Cask Interiora

Cask is sealed; lid is well above flood

plainb

Insert is in a noncorrosive environmentb

Loss of Neutron Poison from

Inserta

a. The degree of flooding or the magnitude of poison loss required to have a

criticality accident is discussed in Section 6.0.

b. Surveillance is required to ensure the integrity of this barrier. Details of

surveillance procedures are documented in Reference .

EXAMPLE # 2

Contingency analysis for a large dissolver vessel. Criticality safety margins are

maintained by controlling the mass of fissile material and the concentration of

neutron poison inside a large dissolver vessel. Inadvertent criticality can occur

by exceeding the fissile mass, dilution or improper makeup of soluble neutron

poison, or by a combination of the two.

Controlsa

Control Parameter

No.

Description

Fissile Mass (U-235)

Mass Balance System # 1

Mass Balance System # 2

Visual Inspection

Concentration of Neutron Poison

Poison Monitor # 1

Poison Monitor # 2

Sampling

A more detailed description of these controls is given in Reference __. At least two

controls are required; no further significance should be placed on the number of controls

listed in this example.