Materials - hdbk60040054

DOE-HDBK-6004-99

Deflection Analysis

An analysis of tritium system deflections over the full range of temperatures, vacuums and pressures

should confirm no interferences or loss of confinement integrity.

Testing and Inspection

Non-destructive testing and inspection of safety-class welds, vessels, piping and valves should be in

accordance with the ASME Boiler and Pressure Vessel Code (ASME 93a). Personnel qualification

and weld acceptance criteria should also be in accordance with ASME 93a.

Testing and inspection should occur before initial operations. The hazards associated with testing

of contaminated systems, processing of the contaminated test medium, and increased potential for

environmental losses of tritium, may impede subsequent periodic testing and inspection. Any system,

subsystem, or component, that is determined to require periodic testing and inspection should be

identified during the design of that system so that the test requirements are incorporated into the

design.

Computational Methods Validation

Computer codes or other computational methods supporting the design of tritium systems should

have validation and verification for the range of normal and off-normal operations including design

basis accidents. This validation and verification should support the use of the computational method

in each intended application.

Materials

Radiation

Materials of construction should be qualified for the lifetime radiation environment. The structural

design analyses should use conservative end-of-life properties. If a component' expected lifetime

is less than the system' lifetime, design should provide for component replacement.

Radiation environment refers principally to external sources of radioactive energy, but it includes the

beta energy of tritium decay also.

Thermal

The structural design analyses should use material properties appropriate for the operating conditions.

If no published materials property data exist for a particular operating temperature, tests should

establish the material properties at the temperature.

The ASME Boiler and Pressure Vessel Code (ASME 93a) imposes temperature limits for structural

designs. For items whose design complies with the Code and whose temperature could exceed the

Code' limit, the design analyses should reduce allowable stress to an acceptable value determined

by testing the material at the elevated temperature.