The identified TLAAs cover the usual areas: fatigue calculations, assessment of embrittlement, changes of material properties, etc. However, the scope of TLAAs for some VVERs differs from the usual one either because of the peculiarities of the design or because of national regulation. For example, in

[19] Analysis of buildings classified into safety category for the verification of the design.

• Fatigue analysis for the containment penetrations.

• Fatigue analysis for the hermetic liner of the containment (welding, tran­sition welding, area of anchors).

• Fatigue analysis for the liner of the spent fuel pool (welding, transition welding, area of anchors).

• Stress and fatigue analysis for the safety-classified crane in the reactor hall with capacity of 250/32/2 tons.

[20] Structural changes in the UO2 due to collection of solid fission products and the effect these structural changes have on the mechanical stability of the fuel during normal and abnormal operation.

[21] How fission product gases are held up within the pores of the pellet and how they are released during upset events.

• Effect of coolant on fuel structure and stability under operating condi­tions when fuel cladding failure occurs.

[22] The oxidation behavior of zirconium alloys at all temperature condi­tions (including high temperature accidents).

• The hydriding of zirconium alloys at all temperature conditions.

[23] Resistance to accidents and departure from nucleate boiling (DNB) or dry-out incidents because of higher operating temperature (~2000°C) capability.

• Minimal hydrogen production due to a much lower rate of reaction with water.

• Ability to operate in much longer cycles due to the very low corrosion rate of SiC in water.

• Enrichment savings due to ~75% lower thermal neutron absorption.

• Uprate capability of ~30% due to the ability to operate at DNB or dry-out conditions.

• Immunity to debris or fretting failures.

[24] Property standards for SiC/SiC-composite matrix ceramic (CMC) mate­rials as applied to LWR’s.

• Mechanical properties as a function of time, temperature and irradiation and use.

• Corrosion properties at high temperatures in oxidizing (steam/air) atmospheres.

• Thermohydraulic response under design basis (LOCA, RIA) and severe accident scenarios.

• Core melt progression and relocation during beyond-design basis accidents.