physics

Safe affordable fission engine

Safe affordable fission engine is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Safe affordable fission engine rather than just read about it. In short: Safe affordable fission engine (SAFE) were NASA's small experimental nuclear fission reactors for electricity production in space. Most known was the SAFE-400 reactor concept intended to produce 400 kW thermal and 100 kW electrical using a Brayton cycle closed-cycle gas turbine.

Key takeaways

Safe affordable fission engine belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Safe affordable fission engine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Safe affordable fission engine from memory before moving on to harder problems.

Reference excerpt

Safe affordable fission engine (SAFE) were NASA's small experimental nuclear fission reactors for electricity production in space. Most known was the SAFE-400 reactor concept intended to produce 400 kW thermal and 100 kW electrical using a Brayton cycle closed-cycle gas turbine. The fuel was uranium nitride in a core of 381 pins clad with rhenium. Three fuel pins surround a molybdenum–sodium heatpipe that transports the heat to a heatpipe-gas heat exchanger. This was called a heatpipe power system. The reactor was about 50 centimetres (20 in) tall, 30 centimetres (12 in) across and weighed about 512 kilograms (1,129 lb). It was developed at the Los Alamos National Laboratory and the Marshall Space Flight Center under the lead of Dave Poston. A smaller test reactor called SAFE-30 was first built. The working fluid used in the reactor was a helium–xenon gas mixture. The project was funded with discretionary money in the lab's budget and done mostly outside the researchers' normal work. As of 2019, this project appears to have been superseded by Nasa's Kilopower.

See also Kilopower Systems Nuclear Auxiliary Power Program and SNAP-10A, that flew in 1965 SP-100

References

Illustrations

Worked examples

Example 1 — a first encounter with Safe affordable fission engine

Start with the simplest possible case. Write down what Safe affordable fission engine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Safe affordable fission engine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Safe affordable fission engine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Safe affordable fission engine

In research: Safe affordable fission engine appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Safe affordable fission engine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Safe affordable fission engine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nuclear power in space, so understanding it makes those chapters shorter.
In everyday life: Look for Safe affordable fission engine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Safe affordable fission engine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Safe affordable fission engine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Safe affordable fission engine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Safe affordable fission engine in simple terms?

Why does Safe affordable fission engine matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Safe affordable fission engine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Safe affordable fission engine.