About 1 hour after shutdown, the decay heat will be about 1.5% of the previous core power. After a day, the decay heat falls to 0.4%, and after a week it will be only 0.2%.
Riboflavin, also known as vitamin B2, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to prevent and treat riboflavin deficiency and prevent migraines. It may be given by mouth or injection. It is nearly always well tolerated.
Milk and milk products such as yogurt and cheese are rich in riboflavin. Asparagus, spinach and other dark green leafy vegetables, chicken, fish, eggs and fortified cereals also supply significant amounts of riboflavin to the diet. Aim for an intake of 1.1 milligrams for women and 1.3 milligrams for men.