Discussion of Contingencies

DOE-STD-3007-93

For Example:

All calculations documented in this evaluation were performed on an IBM

Model 320 RISC 6000 workstation operating under AIX Version 3.1 with

Version 1.1 of the Fortran Compiler. Configuration Release 1.10 of the KENO-

V.a code with Hansen-Roach cross section data were used for this evaluation.

More detailed configuration information is given in Reference .

5.0 DISCUSSION OF CONTINGENCIES

Compliance with the double contingency principle, as stated in DOE Order 5480.24 and

DOE O 420.1, Section 4.3, and the requirements of Section 4.1.2 of ANS-8.1 should be

demonstrated in this section. This may be done by several different methods. Two possible

methods are listed below.

List the independent unlikely events, at least two of which must occur concurrently before

a criticality accident could be possible. Describe the controls, conditions, etc. that ensure

that no credible single failure will result in a criticality. An illustration of this method is

given below (format shown is not a requirement).

Contingency

No.

Description

Barriers

Unlikely Event # 1

Controls, conditions, etc. that make Event

# 1 unlikely

Unlikely Event # 2

Controls, conditions, etc. that make Event

# 2 unlikely

If control of two independent parameters is not practical, DOE 5480.24 and

DOE O 420.1, Section 4.3, allow a system of multiple controls (at least two) on a single

parameter. The overall likelihood of concurrent failure of these controls should be

comparable to two unlikely events as discussed in Method 1. The basis for controlling a

single parameter as opposed to the preferred method of controlling two independent

process parameters should also be documented in this section. An illustration of this

method is given below (format shown is not a requirement).

Controls

Control Parameter

No.

Description

Parameter

Describe Control # 1

Describe Control # N