[justa-hairyape]

Neither does it indicate meltdown. All hydrogen explosions indicate is that the core is hot enough to disassociate water. This is strictly a function of temperature.

Temperature increase is what causes the meltdown.

[BenKenobi]

True, but the temperature required to disassociate hydrogen is quite lower than the temp required for meltdown.

375 degrees Celsius is sufficient, whereas meltdown requires several thousand.