Questions on fixing thorium yellowing with UV light

[Imamacuser]

I have a couple lenses with issues that I'm hoping to fix myself with UV light.

• Vivitar 200mm f/3.5 with thorium yellowing.
• Soligor 135mm f/2 with fungus I want to kill, and eventually cleanout.

Does anyone know what nanometer range is best for correcting thorium yellowing? I've seen UV lights range from 265nm - 400nm.

What nanometer range works well for killing lens fungus?

Any UV lamp or bulb recommendations?

I did a few web searches, but didn't find specific answers to my questions.

Thanks in advance.