Estimating the Probability of Nuclear Power Plant Damage from Rare Tsunamis

[hworth]

Homework Statement

The frequency of a tsunami large enough to threaten the safety of a nuclear power plant has been estimated to be 1 in 200 years. If the plant’s life is 65 years what is the probability it will be damaged by such a tsunami? What is this probability more commonly termed?
[2 Marks]

Homework Equations

How do you get a base event failure rate for components with no recorded failures in an operating time T? Let λ = k/T. A Pessimistic Failure Rate λ = 1/T is known as ‘one tomorrow’. A PSA could use k = 0.5525 (For the estimation of failure rates for low probability events see Progress in Nuclear Energy 4 374-476 1997).

The Attempt at a Solution

Probability of no damage = e^-λT

λ = 0.5525/200

Probability of damage = 1-e-(0.5525/200)(60) = 0.153

A pessimistic failure rate λ=1/T is known as 'one tomorrow'.

Is this correct or completely wrong? Thank you

 

[mfb]

How do you get a base event failure rate for components with no recorded failures in an operating time T? Let λ = k/T. A Pessimistic Failure Rate λ = 1/T is known as ‘one tomorrow’. A PSA could use k = 0.5525 (For the estimation of failure rates for low probability events see Progress in Nuclear Energy 4 374-476 1997).

You are overthinking this. The problem statement gives you the rate. Where this number comes from is a different question not relevant here.

 

[hworth]

You are overthinking this. The problem statement gives you the rate. Where this number comes from is a different question not relevant here.

Are you sure? So would you say 0.325? Seems too simple.

 

[mfb]

You'll still need the exponential function.

 

[hworth]

You'll still need the exponential function.

Do you get 0.259?

λ = 1/200
Probability of damage = 1-e-(1/200)(60) = 0.259

 

[mfb]

That's how I would answer the problem.