100+ Free ANS CNP Practice Questions

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Question 1

Score: 0/0

The CANDU reactor is distinctive because it:

Has no moderator at all

Uses graphite moderation and gas cooling

Requires highly enriched uranium

Uses heavy water as moderator and can run on natural uranium fuel

to track

2026 Statistics

Key Facts: ANS CNP Exam

100

Exam Questions

ANS

2 hrs

Test Time

ANS

$395

Member Fee

ANS

Content Domains

ANS

2 yrs

Experience Required

ANS

3 yrs

Recertification

ANS

The ANS CNP exam has 100 questions and a 2-hour time limit, offered three times per year (spring, summer, fall) at Pearson VUE centers. It costs $395 for ANS members and $595 for non-members, and the credential is valid for 3 years before recertification. The exam spans eight domains led by Nuclear Fundamentals (~20%) and General Nuclear Safety Culture (~15%). Eligibility requires 2 years of nuclear industry experience plus a high school diploma or GED. Question types include single-answer multiple choice, multiple-answer, matching, and drag-and-drop.

Sample ANS CNP Practice Questions

Try these sample questions to test your ANS CNP exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1An atom is best described as neutral when which of the following conditions is met?

A.The number of protons equals the number of electrons

B.The number of neutrons equals the number of protons

C.The number of neutrons equals the number of electrons

D.The mass number equals twice the atomic number

Explanation: An atom carries no net charge when its positive protons are exactly balanced by an equal number of negatively charged electrons. The neutron count (which determines the isotope) does not affect electrical neutrality because neutrons have no charge.

2Two nuclides have the same atomic number but different mass numbers. What term describes this relationship?

A.Isotones

B.Isotopes

C.Isobars

D.Isomers

Explanation: Isotopes share the same number of protons (atomic number Z) but differ in neutron number, giving them different mass numbers A. U-235 and U-238 are classic examples used throughout the nuclear fuel cycle.

3During alpha decay, what happens to the parent nucleus?

A.Atomic number increases by 1, mass number unchanged

B.Atomic number unchanged, mass number decreases by 1

C.Atomic number decreases by 2, mass number decreases by 4

D.Atomic number decreases by 1, mass number unchanged

Explanation: An alpha particle is a helium-4 nucleus (2 protons, 2 neutrons). Emitting it reduces the parent's atomic number by 2 and its mass number by 4. For example, U-238 alpha decays to Th-234.

4In beta-minus decay, which transformation occurs inside the nucleus?

A.A proton converts to a neutron, emitting a positron

B.An electron is captured by a proton

C.An alpha particle is ejected

D.A neutron converts to a proton, emitting an electron and an antineutrino

Explanation: Beta-minus decay converts a neutron into a proton, emitting an electron (the beta particle) and an antineutrino. This raises the atomic number by 1 while leaving the mass number unchanged, as when Co-60 decays toward Ni-60.

5Gamma emission from an excited nucleus is best characterized as which of the following?

A.Release of a high-energy photon with no change in Z or A

B.Release of a neutron that reduces the mass number

C.Conversion of a proton to a neutron

D.Ejection of a helium nucleus

Explanation: Gamma rays are high-energy electromagnetic photons emitted as a nucleus de-excites to a lower energy state. Because no nucleons are emitted, neither the atomic number nor the mass number changes; only the nuclear energy decreases.

6After exactly four half-lives, what fraction of the original radioactive atoms remains?

A.1/4

B.1/16

C.1/8

D.1/32

Explanation: Each half-life reduces the remaining quantity by a factor of two, so after n half-lives the fraction is (1/2)^n. For n = 4, the fraction is (1/2)^4 = 1/16.

7The decay constant (lambda) of a radionuclide is related to its half-life by which expression?

A.lambda = t_half / ln(2)

B.lambda = ln(2) x t_half

C.lambda = ln(2) / t_half

D.lambda = 1 / (2 x t_half)

Explanation: The decay constant equals ln(2) divided by the half-life: lambda = 0.693 / t_half. It represents the probability per unit time that a given nucleus will decay, and activity follows A = lambda x N.

8The binding energy of a nucleus is most directly responsible for which observation?

A.The mass of a nucleus is greater than the sum of its nucleon masses

B.Protons in the nucleus repel each other electrostatically

C.Electrons remain bound in atomic orbitals

D.The mass of a nucleus is less than the sum of its separate nucleon masses

Explanation: Binding energy is the energy that holds nucleons together; per E = mc^2, it appears as a mass deficit, so the assembled nucleus weighs less than its free constituent protons and neutrons. This mass difference is released when the nucleus forms.

9Approximately how much energy is released per fission of a U-235 nucleus?

A.About 200 MeV

B.About 2 MeV

C.About 20 MeV

D.About 2000 MeV

Explanation: Each U-235 fission releases roughly 200 MeV, distributed mainly as kinetic energy of the fission fragments, plus neutrons, gamma rays, and delayed decay energy. This enormous energy density is why nuclear fuel is so compact compared with chemical fuels.

10In reactor physics, the effective multiplication factor keff describes the ratio of neutrons in one generation to the previous generation. A reactor with keff exactly equal to 1.0 is said to be:

A.Subcritical

B.Critical

C.Supercritical

D.Prompt critical

Explanation: When keff = 1.0, each fission generation produces exactly as many neutrons as the prior one, so the chain reaction is self-sustaining at a steady power level. This is the critical condition targeted during normal reactor operation.

About the ANS CNP Exam

The ANS Certified Nuclear Professional (CNP) exam is a 100-question, 2-hour computer-based test administered in person at Pearson VUE test centers. It validates broad knowledge across the nuclear field rather than a single engineering discipline, covering nuclear fundamentals, safety culture, nuclear power, health physics, codes and standards, licensing and regulation, non-power radiation applications, and the fuel cycle and waste management. Eligibility requires at least two years of professional nuclear industry experience and a high school diploma or GED, and the credential must be recertified every three years.

Questions

100 scored questions

Time Limit

2 hours

Passing Score

Scaled score (ANS does not publish a fixed percentage)

Exam Fee

$395 members / $595 non-members (American Nuclear Society (Pearson VUE))

ANS CNP Exam Content Outline

20%

Nuclear Fundamentals

Nuclear structure, reactions, energy release, radioactive decay, half-life, neutron balance, criticality, and radiation interactions

15%

General Nuclear Safety Culture

Safety culture traits, human-performance tools, and lessons from Three Mile Island, Chernobyl, and Fukushima

15%

Nuclear Power

Reactor control and feedback, reactor generations and types (PWR, BWR, CANDU, VVER), SMRs, refueling, and spent-fuel storage

10%

Applied Health Physics

Dosimetry units, dose limits, time/distance/shielding, ALARA, biological effects, and survey instruments

10%

Industry Codes and Standards

Consensus standards, requirements versus guidance, equipment qualification, and commercial grade dedication

10%

Licensing and Regulatory Concepts

Atomic Energy Act, Energy Reorganization Act, Price-Anderson Act, defense-in-depth, FSAR, Tech Specs, and NRC oversight

10%

Non-Power Applications of Radiation

Counting statistics, detectors and spectroscopy, medical and industrial uses, radiogauges, radiotracers, and radiography

10%

Fuel Cycle and Waste Management

Front-end fuel-cycle steps, enrichment, open versus closed cycles, reprocessing, transport packaging, and waste disposal

How to Pass the ANS CNP Exam

What You Need to Know

Passing score: Scaled score (ANS does not publish a fixed percentage)
Exam length: 100 questions
Time limit: 2 hours
Exam fee: $395 members / $595 non-members

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

ANS CNP Study Tips from Top Performers

1Prioritize Nuclear Fundamentals and Safety Culture, which together make up about 35% of the exam

2Memorize key radiation units and conversions (1 Gy = 100 rad, 1 Sv = 100 rem, occupational limit 5 rem/year)

3Know the cause and key lessons of the Three Mile Island, Chernobyl, and Fukushima accidents

4Understand reactor types and how PWRs, BWRs, CANDU, and VVER designs differ

5Learn the major nuclear laws: Atomic Energy Act, Energy Reorganization Act, and Price-Anderson Act

6Practice the time/distance/shielding and inverse-square concepts for external dose control

7Review the front-end fuel-cycle steps and the difference between open and closed cycles

8Practice multiple-answer, matching, and drag-and-drop style items, not just single-answer questions

Frequently Asked Questions

What is the ANS CNP exam?

The Certified Nuclear Professional (CNP) is a credential from the American Nuclear Society that validates broad knowledge across the nuclear field. The exam has 100 questions, a 2-hour time limit, and is administered in person at Pearson VUE test centers. It covers eight domains spanning fundamentals, safety culture, reactors, health physics, codes, regulation, radiation applications, and the fuel cycle.

What are the eligibility requirements for the CNP exam?

Candidates need a minimum of two years of professional nuclear industry experience and a high school diploma or GED equivalent. There is no mandatory training course, though ANS offers a practice exam and preparation resources. Applicants submit an application and pay the exam fee, and ANS members may be eligible to waive the application fee.

How much does the CNP exam cost?

The CNP exam costs $395 for ANS members and $595 for non-members. ANS members may also be eligible to waive the separate application fee. The exam is offered three times per year, in spring, summer, and fall windows, at Pearson VUE testing centers.

How is the CNP exam structured?

The CNP exam consists of 100 questions delivered over a 2-hour testing session, with about 25 additional minutes at the center for administrative tasks. Most questions are single-answer multiple choice, but the exam also uses multiple-answer multiple choice, matching, and drag-and-drop item types. The largest domains are Nuclear Fundamentals (about 20%) and General Nuclear Safety Culture (about 15%).

How long is the CNP credential valid?

The CNP credential is valid for three years. To maintain it, certificate holders must complete the recertification process before the credential expires. This keeps the certification current with evolving industry knowledge and practice.

What topics should I focus on to pass the CNP exam?

Weight your study toward the largest domains: Nuclear Fundamentals (about 20%), General Nuclear Safety Culture (about 15%), and Nuclear Power (about 15%). Then build solid coverage of Applied Health Physics, Industry Codes and Standards, Licensing and Regulatory Concepts, Non-Power Applications of Radiation, and Fuel Cycle and Waste Management, each roughly 10%.