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NS RWM6 practice questions

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Question 1Regulatory Framework and Statutory Authority

Which federal statute is the primary source of authority for the U.S. Nuclear Regulatory Commission to license and regulate commercial nuclear reactors?

  1. The Clean Air Act of 1970
  2. The Federal Power Act of 1935
  3. The Atomic Energy Act of 1954, as amended Correct answer.
  4. The Energy Reorganization Act of 1974

Explanation

The Atomic Energy Act of 1954, as amended, establishes the basic framework for licensing and regulating civilian nuclear materials and facilities, and it is the foundational statute the NRC implements through its regulations. The Energy Reorganization Act restructured the agencies but did not itself create the licensing framework.

Question 2Regulatory Framework and Statutory Authority

The NRC's regulations implementing its statutory authority are codified primarily in which location?

  1. Title 10 of the Code of Federal Regulations Correct answer.
  2. Title 40 of the Code of Federal Regulations
  3. The United States Code, Title 42
  4. The Federal Register only

Explanation

NRC rules appear in Title 10 of the Code of Federal Regulations, with Parts 1 through 199 covering areas such as licensing, radiation protection, and reactor siting. The United States Code contains statutes rather than agency regulations.

Question 3Regulatory Framework and Statutory Authority

Under the Atomic Energy Act, which body holds the ultimate authority to issue a license for a commercial nuclear power reactor?

  1. The state governor of the host state
  2. The NRC, through its licensing boards and Commission Correct answer.
  3. The Federal Energy Regulatory Commission
  4. The Department of Energy

Explanation

The Atomic Energy Act assigns licensing authority to the NRC, exercised through atomic safety and licensing boards with Commission review. States and other federal agencies may participate but cannot issue the federal reactor license.

Question 4Regulatory Framework and Statutory Authority

The Energy Reorganization Act of 1974 accomplished which of the following?

  1. It transferred reactor licensing to the states
  2. It split the Atomic Energy Commission's functions into the NRC and ERDA Correct answer.
  3. It created the Environmental Protection Agency
  4. It repealed the Atomic Energy Act

Explanation

The Energy Reorganization Act dissolved the Atomic Energy Commission and divided its regulatory and promotional functions, creating the NRC as an independent regulator and the Energy Research and Development Administration for development work. The Atomic Energy Act remained the underlying licensing statute.

Question 5Regulatory Framework and Statutory Authority

Which NRC regulation establishes the general requirements for domestic licensing of production and utilization facilities?

  1. 10 CFR Part 50 Correct answer.
  2. 10 CFR Part 100
  3. 10 CFR Part 20
  4. 10 CFR Part 61

Explanation

10 CFR Part 50 contains the domestic licensing requirements for production and utilization facilities, including the general design criteria and technical specification provisions. The other parts address radiation protection, waste disposal, and siting criteria respectively.

Question 6Regulatory Framework and Statutory Authority

Which statute requires federal agencies to consider environmental impacts of major actions and underlies the NRC's environmental review of reactor licensing?

  1. The Administrative Procedure Act
  2. The Low-Level Radioactive Waste Policy Act
  3. The Nuclear Waste Policy Act
  4. The National Environmental Policy Act Correct answer.

Explanation

NEPA requires federal agencies to prepare environmental impact statements for major federal actions significantly affecting the environment, which is why the NRC performs environmental reviews in licensing proceedings. The other statutes govern agency procedure or waste policy specifically.

Question 7Regulatory Framework and Statutory Authority

Which NRC regulation addresses the conduct of proceedings and the role of atomic safety and licensing boards?

  1. 10 CFR Part 2 Correct answer.
  2. 10 CFR Part 50
  3. 10 CFR Part 73
  4. 10 CFR Part 140

Explanation

10 CFR Part 2 sets out the rules of practice for NRC proceedings, including hearing procedures and the functions of atomic safety and licensing boards. The other parts cover licensing requirements, physical protection, and financial protection respectively.

Question 8Regulatory Framework and Statutory Authority

Under the Atomic Energy Act, agreements with states under Section 274 transfer regulatory authority over which of the following?

  1. Certain byproduct, source, and small quantities of special nuclear material Correct answer.
  2. High-level radioactive waste disposal
  3. Commercial power reactor licensing
  4. Export of nuclear equipment

Explanation

Section 274 of the Atomic Energy Act, as amended, allows the NRC to relinquish regulatory authority to states for specified materials such as byproduct, source, and small quantities of special nuclear material. Reactor licensing and export controls remain federal.

Question 9Regulatory Framework and Statutory Authority

A utility wants to build a new reactor design certified by the NRC. Which licensing pathway uses a combined license under 10 CFR Part 52?

  1. An early site permit alone
  2. A construction permit followed later by an operating license under Part 50
  3. A combined construction and operating license referencing a certified design Correct answer.
  4. A general license issued automatically upon design certification

Explanation

Part 52 provides for combined licenses that authorize both construction and, upon verification of specified inspections, tests, analyses, and acceptance criteria, operation of a plant referencing a certified design. The two-step construction permit and operating license process is the Part 50 pathway.

Question 10Regulatory Framework and Statutory Authority

Which agency is responsible for establishing generally applicable environmental radiation protection standards that the NRC must consider in its regulations?

  1. The Federal Emergency Management Agency
  2. The Occupational Safety and Health Administration
  3. The Environmental Protection Agency Correct answer.
  4. The Department of Energy

Explanation

The EPA issues federal guidance and generally applicable environmental standards for radiation protection, and the NRC considers these in developing its own regulations. The other agencies have different missions and do not set these cross-cutting radiation standards.

Question 11Regulatory Framework and Statutory Authority

An applicant files a construction permit application. Under the Atomic Energy Act, what must the NRC find before issuing the permit?

  1. The design has been certified under Part 52
  2. The facility will not be inimical to the common defense and security or public health and safety Correct answer.
  3. The applicant has secured a state operating permit
  4. The applicant has obtained a waste repository license

Explanation

The Atomic Energy Act directs the Commission to issue licenses only upon findings that the activity will not be inimical to the common defense and security and will provide adequate protection of public health and safety. State permits and design certification are not statutory prerequisites to a Part 50 construction permit.

Question 12Regulatory Framework and Statutory Authority

Which statute provides the basis for NRC regulation of the physical protection of nuclear facilities and materials against sabotage and theft?

  1. The Freedom of Information Act
  2. The Atomic Energy Act, as amended by later legislation Correct answer.
  3. The National Historic Preservation Act
  4. The Clean Water Act

Explanation

Safeguards and physical protection requirements derive from the Atomic Energy Act and its amendments, which authorize the Commission to impose security requirements to protect facilities and special nuclear material. The other statutes address water pollution, historic preservation, and public records access.

Question 13Regulatory Framework and Statutory Authority

A state wishes to regulate radiological hazards at an NRC-licensed reactor. How does federal preemption generally apply?

  1. States may impose stricter radiological limits than the NRC at any time
  2. Counties hold concurrent radiological authority with the NRC
  3. Federal authority generally preempts state regulation of radiological hazards, though states retain certain non-radiological roles Correct answer.
  4. States have exclusive authority over radiological hazards at licensed reactors

Explanation

The Atomic Energy Act and Supreme Court precedent establish that federal authority occupies the field of radiological safety at licensed facilities, while states may regulate non-radiological matters such as land use and certain economic aspects. States cannot impose their own radiological safety standards on NRC licensees.

Question 14Regulatory Framework and Statutory Authority

Which NRC regulation implements the requirements for financial protection and indemnity for nuclear incidents?

  1. 10 CFR Part 71
  2. 10 CFR Part 140 Correct answer.
  3. 10 CFR Part 30
  4. 10 CFR Part 55

Explanation

10 CFR Part 140 sets financial protection requirements and indemnity agreements consistent with the Price-Anderson Act framework. The other parts address byproduct material licensing, operator licensing, and transportation packaging.

Question 15Regulatory Framework and Statutory Authority

An intervenor challenges whether the NRC has authority to regulate a particular activity. Which document type best establishes the agency's interpretation of its governing statute?

  1. A press release from a utility
  2. A state statute enacted by the legislature
  3. A Commission statement of policy or rulemaking preamble issued under its statutory authority Correct answer.
  4. A Nuclear Regulatory Commission newsletter article

Explanation

Agency interpretations of the statutes it administers are expressed through rulemaking preambles, policy statements, and adjudicatory decisions, and courts generally defer to reasonable agency interpretations within statutory bounds. State statutes and utility communications do not define federal agency authority.

Question 16Regulatory Framework and Statutory Authority

Under the Price-Anderson framework, what is the principal purpose of the indemnity provisions?

  1. To pay NRC operating costs
  2. To provide a mechanism for compensating the public for damages from a nuclear incident beyond available insurance Correct answer.
  3. To fund decommissioning of reactors
  4. To cap utility electricity rates

Explanation

The Price-Anderson Act establishes a system of private insurance plus industry retrospective payments and government indemnity to assure compensation for public liability from a nuclear incident. It does not set electricity rates, fund decommissioning, or finance NRC operations.

Question 17Regulatory Framework and Statutory Authority

Which NRC regulation governs the licensing of operators of production and utilization facilities?

  1. 10 CFR Part 20
  2. 10 CFR Part 60
  3. 10 CFR Part 40
  4. 10 CFR Part 55 Correct answer.

Explanation

10 CFR Part 55 establishes the requirements for operators' licenses, including training, examination, and requalification. The other parts cover radiation protection, source material licensing, and disposal of high-level waste.

Question 18Regulatory Framework and Statutory Authority

An applicant submits an early site permit application. What does an early site permit authorize?

  1. It authorizes operation at full power
  2. It authorizes immediate construction of the reactor
  3. It resolves site suitability issues but does not authorize construction or operation Correct answer.
  4. It replaces the need for a combined license

Explanation

An early site permit under Part 52 resolves site-related issues such as seismology and environmental impacts in advance, but construction and operation still require a separate combined license or construction permit. It is a site pre-approval, not an authorization to build or run a plant.

Question 19Regulatory Framework and Statutory Authority

Which federal statute governs the disposal of high-level radioactive waste and established the framework for a geologic repository?

  1. The Clean Air Act
  2. The Nuclear Waste Policy Act Correct answer.
  3. The Safe Drinking Water Act
  4. The Resource Conservation and Recovery Act

Explanation

The Nuclear Waste Policy Act establishes the national policy and program for disposing of high-level radioactive waste and spent fuel in a geologic repository. The other statutes address air pollution, drinking water, and solid and hazardous waste generally.

Question 20Regulatory Framework and Statutory Authority

An NRC licensee disputes a compliance order. Which statute establishes the right to judicial review of final agency action?

  1. The Sherman Antitrust Act
  2. The Federal Tort Claims Act
  3. The Administrative Procedure Act and the Atomic Energy Act's judicial review provisions Correct answer.
  4. The Tucker Act

Explanation

Final NRC actions are reviewable in federal court under the Administrative Procedure Act and the judicial review provisions of the Atomic Energy Act, which specify the appropriate court and standards. The other statutes address tort claims, contract claims, and antitrust matters.

Question 21Regulatory Framework and Statutory Authority

How does the NRC's authority to impose civil penalties arise?

  1. From international treaty obligations
  2. From the Federal Power Act
  3. From state statutes adopted by reference
  4. From statutory authority in the Atomic Energy Act, exercised through regulations in 10 CFR Part 2 Correct answer.

Explanation

The Atomic Energy Act authorizes the Commission to impose civil penalties for violations, and the procedures are set out in the NRC's rules of practice in 10 CFR Part 2. State statutes, the Federal Power Act, and treaties do not create this penalty authority.

Question 22Regulatory Framework and Statutory Authority

A court reviews an NRC rule interpreting an ambiguous provision of the Atomic Energy Act. Which principle generally governs the court's analysis?

  1. The court requires congressional ratification of the rule
  2. The court assesses whether the agency's interpretation is reasonable and within the statute Correct answer.
  3. The court defers only if the state agrees
  4. The court substitutes its own interpretation without deference

Explanation

Under established administrative law principles, courts evaluate whether an agency's interpretation of an ambiguous statute it administers is reasonable and consistent with the statutory framework. Courts do not simply substitute their own reading, nor do they require state consent or congressional ratification.

Question 23Regulatory Framework and Statutory Authority

Which statement best describes the relationship between the Atomic Energy Act and NRC regulations?

  1. Regulations may override conflicting statutory provisions
  2. Regulations apply only to DOE facilities
  3. Regulations must be consistent with and implement the statutory framework Correct answer.
  4. Regulations are advisory only

Explanation

Agency regulations are subordinate to the statute and must implement and remain consistent with it; a rule that conflicts with the statute is invalid. Regulations are binding on licensees and are not advisory, and they apply broadly to NRC licensees rather than only to DOE facilities.

Question 24Regulatory Framework and Statutory Authority

A state proposes to license a radioactive waste disposal facility within its borders. Under the Low-Level Radioactive Waste Policy Act framework, which statement is accurate?

  1. States may license high-level waste repositories without federal involvement
  2. States may assume responsibility for low-level waste disposal under compact and NRC-approved arrangements Correct answer.
  3. States may export waste without any federal or compact controls
  4. States may regulate reactor radiological safety concurrently with the NRC

Explanation

The Low-Level Radioactive Waste Policy Act encourages states to provide for disposal of low-level waste, often through interstate compacts, with NRC-approved programs where agreement state authority applies. High-level waste repository licensing remains federal, reactor radiological safety is preempted, and exports are subject to federal controls.

Question 25Regulatory Framework and Statutory Authority

Which combination correctly pairs a statutory source with the regulatory part that implements it for reactor licensing hearings?

  1. Clean Air Act with 10 CFR Part 50
  2. Price-Anderson Act with 10 CFR Part 20
  3. National Environmental Policy Act with 10 CFR Part 55
  4. Atomic Energy Act with 10 CFR Part 2 Correct answer.

Explanation

The Atomic Energy Act's hearing and licensing provisions are implemented procedurally through the rules of practice in 10 CFR Part 2. The other pairings mismatch statutes with unrelated regulatory parts.

Question 26Regulatory Framework and Statutory Authority

Which federal statute establishes the basic framework for licensing and regulating civilian nuclear reactors in the United States?

  1. The Atomic Energy Act of 1954 Correct answer.
  2. The Administrative Procedure Act
  3. The Federal Power Act
  4. The Clean Air Act

Explanation

The Atomic Energy Act of 1954, as amended, gives the NRC its core authority to license and regulate civilian production and utilization facilities, including power reactors. Other statutes may add requirements, but the AEA is the foundational licensing statute.

Question 27Regulatory Framework and Statutory Authority

A licensee receives an NRC notice of violation and wishes to challenge the agency's final action in federal court. Which statute provides the general framework for judicial review of such agency action?

  1. The National Environmental Policy Act
  2. The Hobbs Administrative Orders Review Act
  3. The Administrative Procedure Act Correct answer.
  4. The Nuclear Waste Policy Act

Explanation

The Administrative Procedure Act supplies the general standards and framework for judicial review of final agency action, including scope-of-review principles such as whether action is arbitrary or contrary to law. Specific statutes may channel review to particular courts, but the APA provides the baseline framework.

Question 28Regulatory Framework and Statutory Authority

An applicant seeks NRC approval for a standard reactor design before selecting a site. Which licensing process is designed to approve a design generically so it can later be referenced in a combined license application?

  1. Construction permit
  2. Operating license amendment
  3. Early site permit
  4. Design certification Correct answer.

Explanation

Design certification is a rulemaking that approves a standard plant design generically, independent of a specific site, so future applicants may reference the certified design in a combined license application. This separation allows design review to occur before site-specific decisions.

Question 29Regulatory Framework and Statutory Authority

A state enacts a law that directly conflicts with an NRC regulation governing radiation protection at a licensed reactor. How is such a conflict generally resolved under the Supremacy Clause?

  1. The conflict is resolved by the state governor's office.
  2. The NRC regulation prevails and the conflicting state requirement is preempted. Correct answer.
  3. The state law prevails because states retain police powers over health and safety.
  4. The two requirements apply concurrently and the licensee must satisfy both.

Explanation

Under the Supremacy Clause, federal law and valid federal regulations prevail over conflicting state law, so a state requirement that directly conflicts with NRC radiation protection regulation is preempted. States may still exercise authority in areas the federal scheme leaves open.

Question 30Regulatory Framework and Statutory Authority

A court reviews an NRC interpretation of an ambiguous term in the Atomic Energy Act. Which principle generally governs the court's analysis of the agency's interpretation?

  1. The court decides the meaning de novo without any deference to the agency.
  2. The court remands to Congress for a statutory clarification.
  3. The court must adopt the interpretation proposed by the intervening party.
  4. The court defers to the agency's interpretation if it is reasonable and the statute is ambiguous. Correct answer.

Explanation

Under the familiar two-step framework, a court first asks whether Congress has spoken directly to the question; if the statute is silent or ambiguous, the court generally upholds a permissible agency interpretation. This reflects the agency's delegated authority to administer the statute.

Question 31Radiation Protection Principles and Dose Limits

Which dose limit applies to the lens of the eye for a radiation worker under ICRP recommendations?

  1. 20 mSv per year averaged over defined periods of 5 years Correct answer.
  2. 500 mSv per year
  3. 15 mSv per year
  4. 150 mSv per year

Explanation

The ICRP reduced the occupational equivalent dose limit for the lens of the eye to 20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. This change reflected evidence that cataract induction occurs at lower doses than previously assumed.

Question 32Radiation Protection Principles and Dose Limits

What is the ICRP occupational effective dose limit averaged over five years?

  1. 50 mSv
  2. 1 mSv per year
  3. 20 mSv per year Correct answer.
  4. 100 mSv per year

Explanation

The occupational effective dose limit is 20 mSv per year averaged over defined periods of 5 years, with a maximum of 50 mSv in any single year. The averaging allows flexibility while controlling cumulative risk.

Question 33Radiation Protection Principles and Dose Limits

What is the annual effective dose limit for members of the public from all artificial sources, excluding medical exposure?

  1. 20 mSv
  2. 5 mSv
  3. 1 mSv Correct answer.
  4. 0.1 mSv

Explanation

The public effective dose limit is 1 mSv per year, applied to all artificial sources other than medical exposures. This is one-twentieth of the occupational average, reflecting the absence of benefit to the individual.

Question 34Radiation Protection Principles and Dose Limits

Which quantity is defined as the absorbed dose averaged over a tissue or organ, weighted for radiation type?

  1. Absorbed dose
  2. Committed dose
  3. Effective dose
  4. Equivalent dose Correct answer.

Explanation

Equivalent dose is the mean absorbed dose in a tissue multiplied by the radiation weighting factor for the type of radiation. It accounts for the differing biological effectiveness of alpha particles, neutrons, and photons.

Question 35Radiation Protection Principles and Dose Limits

What is the SI unit of equivalent dose and effective dose?

  1. Coulomb per kilogram
  2. Gray
  3. Sievert Correct answer.
  4. Becquerel

Explanation

The sievert is the SI unit for equivalent dose and effective dose, representing the weighted biological effect. One sievert equals one joule per kilogram after applying the relevant weighting factors.

Question 36Radiation Protection Principles and Dose Limits

Which principle requires that no practice involving radiation exposure be adopted unless it produces sufficient benefit to offset the harm?

  1. ALARA
  2. Optimisation
  3. Dose limitation
  4. Justification Correct answer.

Explanation

Justification is the principle that a practice must do more good than harm before it is adopted. Optimisation and dose limitation apply only after a practice has been justified.

Question 37Radiation Protection Principles and Dose Limits

What is the radiation weighting factor for alpha particles as used in ICRP equivalent dose calculations?

  1. 5
  2. 1
  3. 20 Correct answer.
  4. 2

Explanation

Alpha particles are assigned a radiation weighting factor of 20, reflecting their high linear energy transfer and dense ionisation tracks. Photons and electrons have a weighting factor of 1.

Question 38Radiation Protection Principles and Dose Limits

Which body issues the international recommendations on which many national radiation protection regulations are based?

  1. WHO
  2. UNSCEAR
  3. ICRP Correct answer.
  4. IAEA

Explanation

The International Commission on Radiological Protection publishes the fundamental recommendations on dose limits and protection principles that national regulators adopt. The IAEA builds binding standards for its member states upon these recommendations.

Question 39Radiation Protection Principles and Dose Limits

A worker receives an effective dose of 2 mSv from external gamma exposure and 3 mSv from an intake of a radionuclide. What is the total effective dose recorded for the year?

  1. 6 mSv
  2. 2 mSv
  3. 5 mSv Correct answer.
  4. 3 mSv

Explanation

Effective doses from external exposure and from intakes are additive for the purpose of compliance with dose limits. The committed effective dose from the intake is added to the external dose to give 5 mSv.

Question 40Radiation Protection Principles and Dose Limits

A worker has accumulated 60 mSv over the previous four years. What is the maximum effective dose permitted in the fifth year to comply with a 20 mSv per year 5-year average?

  1. 40 mSv Correct answer.
  2. 50 mSv
  3. 60 mSv
  4. 20 mSv

Explanation

The 5-year total limit is 100 mSv, so the remaining allowance is 100 minus 60, which equals 40 mSv. This also satisfies the single-year cap of 50 mSv.

Question 41Radiation Protection Principles and Dose Limits

An absorbed dose of 0.5 mGy is delivered by alpha radiation. What is the equivalent dose to the tissue?

  1. 5 mSv
  2. 2.5 mSv
  3. 0.5 mSv
  4. 10 mSv Correct answer.

Explanation

Equivalent dose equals absorbed dose multiplied by the radiation weighting factor. For alpha particles the factor is 20, so 0.5 mGy times 20 gives 10 mSv.

Question 42Radiation Protection Principles and Dose Limits

Why does the effective dose use tissue weighting factors in addition to radiation weighting factors?

  1. To convert absorbed dose into activity
  2. To correct for the decay of short-lived radionuclides
  3. To adjust for the energy of the incident photon beam
  4. To account for differing radiosensitivity of organs for stochastic effects Correct answer.

Explanation

Tissue weighting factors reflect that organs differ in their sensitivity to stochastic effects such as cancer induction. Summing weighted organ doses gives a whole-body indicator of risk.

Question 43Radiation Protection Principles and Dose Limits

What is the committed effective dose for an adult following an intake whose equivalent doses are delivered over 50 years?

  1. The dose received in the first 7 days
  2. The dose remaining after radioactive decay is complete
  3. The total dose integrated over 50 years after the intake Correct answer.
  4. The dose received in the first year only

Explanation

Committed effective dose integrates the equivalent dose in each tissue over 50 years for adults following a single intake. This captures the full stochastic risk from long-lived radionuclides retained in the body.

Question 44Radiation Protection Principles and Dose Limits

Which concept describes a restriction on individual dose from a single source used to ensure overall optimisation across multiple sources?

  1. Dose constraint Correct answer.
  2. Dose limit
  3. Action level
  4. Reference level

Explanation

A dose constraint is a prospective restriction on the dose from a single source, set below the relevant limit. It guides optimisation when several sources contribute to an individual's total exposure.

Question 45Radiation Protection Principles and Dose Limits

A worker's annual whole-body dose is 18 mSv. Which statement best describes compliance with the occupational limit?

  1. The dose is non-compliant because any dose above 10 mSv is prohibited
  2. The dose is acceptable only if the worker consents in writing
  3. The limit is exceeded because it exceeds 15 mSv
  4. The dose is within the 20 mSv annual average but must be optimised Correct answer.

Explanation

A dose of 18 mSv is below the 20 mSv annual average and the 50 mSv single-year cap. However, the ALARA principle still requires that doses be optimised and not simply accepted because they fall under the limit.

Question 46Radiation Protection Principles and Dose Limits

Which exposure situation category covers radon in dwellings and contamination from past activities?

  1. Existing exposure situation Correct answer.
  2. Emergency exposure situation
  3. Occupational exposure situation
  4. Planned exposure situation

Explanation

Existing exposure situations are those that already exist when a decision on control must be taken, such as natural background radon and residual contamination. They are managed through reference levels rather than fixed dose limits.

Question 47Radiation Protection Principles and Dose Limits

A radiographer stands 2 m from a point source. If the distance doubles to 4 m, what happens to the dose rate assuming no shielding?

  1. It quarters Correct answer.
  2. It halves
  3. It remains unchanged
  4. It doubles

Explanation

For a point source, dose rate falls with the inverse square of distance. Doubling the distance increases the divisor by a factor of four, so the dose rate becomes one quarter.

Question 48Radiation Protection Principles and Dose Limits

Which quantity is used to express the stochastic risk from a given exposure and is the basis for regulatory dose limits?

  1. Absorbed dose in air
  2. Equivalent dose to the skin
  3. Activity administered
  4. Effective dose Correct answer.

Explanation

Effective dose combines organ equivalent doses with tissue weighting factors to give a single value proportional to stochastic risk. Dose limits are expressed in effective dose for whole-body exposures.

Question 49Radiation Protection Principles and Dose Limits

What is the primary purpose of dose limitation as a protection principle?

  1. To set reference levels for emergencies
  2. To keep doses as low as reasonably achievable
  3. To prevent deterministic effects and limit stochastic risk to individuals Correct answer.
  4. To justify the introduction of a new practice

Explanation

Dose limitation sets boundaries that prevent deterministic effects and keep stochastic risk at an acceptable level for any individual. It complements justification and optimisation rather than replacing them.

Question 50Radiation Protection Principles and Dose Limits

Which annual equivalent dose limit applies to the skin of a radiation worker, averaged over any 1 cm² area?

  1. 20 mSv
  2. 50 mSv
  3. 150 mSv
  4. 500 mSv Correct answer.

Explanation

The occupational equivalent dose limit for skin is 500 mSv per year, averaged over any 1 cm² regardless of the area exposed. This high value reflects the skin's capacity to repair damage and the localised nature of exposure.