Pcm to reactor period
Type a value in pcm to get it in s instantly.
84.7s
That's about the same as a control rod step. That is about 0.15 dollars of reactivity.
What it means
How far from critical?
Dollars use β = 0.0065 for uranium-235. A plutonium-fuelled or high-burnup core has a smaller β, so the same pcm is worth more dollars.
The math
How to convert pcm to s
The multiplication factor follows from the reactivity: k = 1 ÷ (1 − ρ) with ρ as a fraction. A dollar is one delayed neutron fraction, 650 pcm for uranium-235, and the period is about 8,470 ÷ pcm seconds.
Example: 100 pcm = 84.7 s.
Every unit
Your reactivity in every unit
Tables
pcm to s conversion table
| pcm | s |
|---|---|
| 1 pcm | 8,470 s |
| 10 pcm | 847 s |
| 50 pcm | 169.4 s |
| 100 pcm | 84.7 s |
| 250 pcm | 33.88 s |
| 500 pcm | 16.94 s |
| 650 pcm | 13.0308 s |
| 1,000 pcm | 8.47 s |
| 2,000 pcm | 4.235 s |
| 5,000 pcm | 1.694 s |
s to pcm conversion table
| s | pcm |
|---|---|
| 1 s | 8,470 pcm |
| 10 s | 847 pcm |
| 50 s | 169.4 pcm |
| 100 s | 84.7 pcm |
| 250 s | 33.88 pcm |
| 500 s | 16.94 pcm |
| 650 s | 13.0308 pcm |
| 1,000 s | 8.47 pcm |
| 2,000 s | 4.235 pcm |
| 5,000 s | 1.694 pcm |
Quick answers
Quick answers
- How many s is 1 pcm?
- 1 pcm is 8,470 s.
- How many s is 10 pcm?
- 10 pcm is 847 s.
- How many s is 100 pcm?
- 100 pcm is 84.7 s.
The units
About these units
Pcm (pcm)
Per cent mille: hundred-thousandths of reactivity.
Reactor period (s)
Seconds for the power to multiply by e, for small reactivity.
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