100+ Free ABSNM RP Practice Questions

Pass your ABSNM Radiation Protection Certification exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately

Not publicly reported (chart only on ABSNM website) Pass Rate

100+ Questions

100% Free

1 / 10

Question 1

Score: 0/0

Which type of photon interaction with matter is most probable at low photon energies and high atomic number absorbers?

Compton scattering

Photoelectric effect

Pair production

Coherent (Rayleigh) scattering

to track

2026 Statistics

Key Facts: ABSNM RP Exam

280

Total Questions

180 (Part 1) + 100 (Part 2)

6 hrs

Exam Time

3.5h + 2.5h with lunch break

$1,000+

Exam Fee

ABSNM 2026 fee schedule

NRC

RSO Recognition

10 CFR 35.50

5 yrs

Required Experience

3 years in applied health physics

1x/yr

Exam Frequency

In-person, single date

The ABSNM RP exam is a two-part, paper-based exam: Part 1 (180 general questions, 3.5h) + Part 2 (100 radiation protection questions, 2.5h). Fee: $1,000-$1,030. Administered in-person once per year (May 23, 2026 in Raleigh-Durham, NC). Requires master's/doctorate + 5 years health physics experience (3 in applied HP). NRC-recognized under 10 CFR 35.50. 4-year certification with 100 CE hours for MOC.

Sample ABSNM RP Practice Questions

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

1Which type of photon interaction with matter is most probable at low photon energies and high atomic number absorbers?

A.Compton scattering

B.Photoelectric effect

C.Pair production

D.Coherent (Rayleigh) scattering

Explanation: The photoelectric effect dominates at low photon energies and in high-Z materials because its probability is proportional to Z³/E³. This interaction results in complete absorption of the photon and ejection of an inner-shell electron, making it the primary contributor to patient dose at diagnostic energies in high-Z tissues.

2In Compton scattering, the energy of the scattered photon depends on which of the following?

A.The atomic number of the absorber

B.The scattering angle and incident photon energy

C.The binding energy of the K-shell electron

D.The density of the absorbing material

Explanation: In Compton scattering, the scattered photon energy is determined by the scattering angle and the incident photon energy, as described by the Compton equation. The interaction occurs with loosely bound outer-shell electrons and is essentially independent of the atomic number of the absorber.

3What is the minimum photon energy required for pair production to occur?

A.0.511 MeV

B.1.022 MeV

C.1.533 MeV

D.2.044 MeV

Explanation: Pair production requires a minimum photon energy of 1.022 MeV, which equals twice the rest mass energy of an electron (2 × 0.511 MeV). The photon interacts with the nuclear Coulomb field and is converted into an electron-positron pair, with any excess energy shared as kinetic energy between the two particles.

4A point source produces an exposure rate of 100 mR/hr at 1 meter. What is the exposure rate at 3 meters?

A.33.3 mR/hr

B.11.1 mR/hr

C.9.0 mR/hr

D.25.0 mR/hr

Explanation: According to the inverse square law, exposure rate decreases as the square of the distance: I₂ = I₁ × (d₁/d₂)² = 100 × (1/3)² = 100/9 ≈ 11.1 mR/hr. Tripling the distance from a point source reduces the intensity by a factor of nine.

5Bremsstrahlung radiation is most efficiently produced when:

A.Low-energy electrons interact with low-Z targets

B.High-energy electrons interact with high-Z targets

C.Alpha particles interact with tissue

D.Thermal neutrons interact with hydrogen

Explanation: Bremsstrahlung (braking radiation) production efficiency is proportional to Z × E, where Z is the atomic number of the target and E is the kinetic energy of the charged particle. High-energy electrons interacting with high-Z targets (e.g., tungsten) produce bremsstrahlung most efficiently, which is the principle behind X-ray tube design.

6If a broad beam of 140 keV photons has a half-value layer (HVL) of 0.25 mm Pb, what thickness of lead is needed to reduce the intensity to 1/8 of its original value?

A.0.50 mm Pb

B.0.75 mm Pb

C.1.00 mm Pb

D.1.25 mm Pb

Explanation: Reducing intensity to 1/8 requires 3 half-value layers because (1/2)³ = 1/8. With an HVL of 0.25 mm Pb, the required thickness is 3 × 0.25 = 0.75 mm Pb. This calculation assumes narrow-beam geometry (good geometry conditions) where buildup is negligible.

7The tenth-value layer (TVL) of a material is related to the half-value layer (HVL) by which factor?

A.TVL = 2.0 × HVL

B.TVL = 3.32 × HVL

C.TVL = 5.0 × HVL

D.TVL = 10.0 × HVL

Explanation: The TVL equals 3.32 × HVL. This relationship derives from the exponential attenuation law: TVL = ln(10)/μ and HVL = ln(2)/μ, so TVL/HVL = ln(10)/ln(2) = 2.303/0.693 ≈ 3.32. One TVL reduces intensity to 10%, requiring approximately 3.32 halvings.

8Which statement correctly describes the relationship between linear energy transfer (LET) and relative biological effectiveness (RBE)?

A.RBE increases linearly with LET without limit

B.RBE increases with LET up to approximately 100 keV/μm, then decreases

C.RBE is inversely proportional to LET at all values

D.RBE remains constant regardless of LET

Explanation: RBE increases with LET up to an optimal value around 100 keV/μm, after which it decreases due to the overkill effect. At very high LET values, more energy is deposited than needed to cause lethal damage to a cell, so the excess energy is wasted, reducing the biological effectiveness per unit dose.

9In cell survival curves, the shoulder region observed with low-LET radiation is attributed to:

A.Single-hit killing at low doses

B.Sublethal damage repair at low doses

C.The oxygen enhancement ratio increasing with dose

D.Bystander effects in neighboring cells

Explanation: The shoulder on a cell survival curve for low-LET radiation reflects the accumulation and repair of sublethal damage at low doses. At these doses, cells can repair some of the radiation damage before it becomes lethal. As dose increases, repair capacity is overwhelmed and the curve becomes steeper, approaching an exponential decline.

10The oxygen enhancement ratio (OER) for low-LET radiation is approximately:

A.1.0

B.1.5

C.2.5–3.0

D.5.0–6.0

Explanation: The OER for low-LET radiation such as X-rays and gamma rays is approximately 2.5–3.0, meaning that hypoxic cells require 2.5 to 3 times the dose of aerobic cells to achieve the same level of cell killing. Oxygen enhances the indirect effect of radiation by reacting with free radicals to form organic peroxides, preventing chemical repair.

About the ABSNM RP Exam

The ABSNM Radiation Protection certification designates Diplomates (DABSNM) in radiation protection from radionuclides. The two-part exam covers general nuclear medicine science (Part 1: 180 questions, 3.5h) and radiation protection specialty topics (Part 2: 100 questions, 2.5h). Topics include radiation physics, biology, detection/measurement, health physics, NRC regulations (10 CFR 20/35), internal dosimetry, and applied radiation safety. NRC-recognized under 10 CFR 35.50 for RSO eligibility.

Questions

280 scored questions

Time Limit

6 hours (Part 1: 3.5h, Part 2: 2.5h)

Passing Score

Criterion-referenced (not publicly disclosed)

Exam Fee

$1,000–$1,030 (ABSNM)

ABSNM RP Exam Content Outline

~20%

NRC Regulatory Requirements

10 CFR 20/35, dose limits, RSO responsibilities, medical events, written directives, waste disposal, transportation

~20%

Health Physics & Dose Calculations

Absorbed/equivalent/effective dose, ALARA, shielding calculations, internal dosimetry, MIRD, ALI, DAC

~15%

Radiation Physics

Photon interactions, Compton scattering, photoelectric effect, inverse square law, HVL/TVL

~15%

Radiation Biology

Cell survival curves, DNA damage, LET, RBE, deterministic/stochastic effects, dose-response models, LNT

~15%

Radiation Detection & Measurement

Ion chambers, GM detectors, TLDs, OSLDs, counting statistics, MDA, contamination surveys

~15%

Applied Radiation Protection

I-131/Lu-177 safety, patient release criteria, brachytherapy, emergency procedures, decontamination

How to Pass the ABSNM RP Exam

What You Need to Know

Passing score: Criterion-referenced (not publicly disclosed)
Exam length: 280 questions
Time limit: 6 hours (Part 1: 3.5h, Part 2: 2.5h)
Exam fee: $1,000–$1,030

Keys to Passing

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

ABSNM RP Study Tips from Top Performers

1NRC regulations dominate — master 10 CFR 20 (dose limits, ALARA, monitoring) and 10 CFR 35 (medical use, written directives, medical events)

2Know dose limits cold: 50 mSv/year occupational whole body, 500 mSv extremities, 1 mSv public, 5 mSv fetus over gestation

3Practice shielding calculations: HVL/TVL, exposure rate constants, inverse square law, barrier thickness for therapy rooms

4Understand radiation biology models: LNT, linear-quadratic, cell survival curves, and their regulatory implications

5Study applied safety scenarios: I-131 patient release (7 mR/hr at 1m), spill decontamination procedures, and Lu-177 theranostic safety

Frequently Asked Questions

What is the ABSNM RP exam format?

Two-part exam on one day: Part 1 is 180 general questions in 3.5 hours, Part 2 is 100 radiation protection specialty questions in 2.5 hours. Paper-based (Scantron) with a provided TI-30XS calculator.

What are the prerequisites?

Master's or doctorate in physical science/engineering/health physics, plus 5 years health physics experience (3 in applied HP). Graduate training may substitute for up to 2 years.

Does ABSNM RP certification qualify me as an RSO?

Yes. ABSNM Radiation Protection certification is NRC-recognized under 10 CFR 35.50 for RSO eligibility with relevant experience.

When is the 2026 exam?

May 23, 2026 in Raleigh-Durham, NC. Once per year, in person only. Application deadline was March 1, 2026.