How long is a year?

[Jeremy]

When I specify and irradiation or decay time in ORIGEN (or other SCALE 6.1.3 module) in terms of years, how is the conversion to other units carried out?  Is a year treated as being 365.25 days or 365.2422 days?

Jeremy

[Steve Skutnik]

Hi Jeremy,

Origen defines a year as 365.25 days. (How to treat this going forward was a subject of some internal deliberation, however it was decided to settle upon this definition based on its common usage.) Specifically, a year converts to 365.25 * 86400 seconds (i.e., 365.25 * 24 * 60 * 60).

-Steve