CHP CHP Radioactive Materials Handling & Waste Management 2 — Questions and Answers
Question 1: According to 10 CFR 61, into which categories is Low-Level Radioactive Waste (LLW) classified?
- Class I, II, and III
- Class A, B, C, and Greater-than-Class-C (GTCC) (Correct answer)
- Low activity, medium activity, and high activity
- Exempt, limited, and regulated
Correct answer: Class A, B, C, and Greater-than-Class-C (GTCC)
10 CFR 61 classifies LLW as Class A, B, C, and Greater-than-Class-C based on radionuclide concentrations and half-lives, with progressively stricter disposal requirements.
Question 2: What defines 'mixed waste' in the context of US radioactive waste management regulations?
- Waste containing both alpha and beta-emitting radionuclides
- Waste that is simultaneously radioactive and hazardous under RCRA (Correct answer)
- Waste combining both low-level and high-level radioactive materials
- Waste generated from multiple radiation-producing operations
Correct answer: Waste that is simultaneously radioactive and hazardous under RCRA
Mixed waste is subject to both NRC (or Agreement State) radioactive waste regulations and EPA's Resource Conservation and Recovery Act (RCRA) for hazardous waste.
Question 3: Which radioactive waste disposal method is most cost-effective for short-lived isotopes like H-3, C-14, and P-32 in a research laboratory?
- Immediate shipment to a licensed LLW disposal facility
- Decay-in-storage until activity falls below release thresholds, then dispose as regular trash (Correct answer)
- Incineration in a standard municipal waste incinerator
- Dilution and release to the sanitary sewer system
Correct answer: Decay-in-storage until activity falls below release thresholds, then dispose as regular trash
Decay-in-storage (DIS) allows short-lived isotopes to decay to background levels, eliminating the cost of licensed radioactive waste disposal.
Question 4: What primary characteristic defines Transuranic (TRU) waste and distinguishes it from other low-level radioactive waste?
- TRU waste has half-lives shorter than 20 years
- TRU waste contains alpha-emitting radionuclides with atomic numbers greater than uranium at >100 nCi/g (Correct answer)
- TRU waste is generated exclusively at commercial nuclear power plants
- TRU waste is defined by its high thermal output per unit volume
Correct answer: TRU waste contains alpha-emitting radionuclides with atomic numbers greater than uranium at >100 nCi/g
TRU waste contains alpha-emitting transuranic radionuclides (atomic number > 92) at concentrations exceeding 100 nCi/g, primarily generated during nuclear weapons production.
Question 5: Under 10 CFR 20.2003, what conditions must be met before radioactive materials may be disposed of via release to a sanitary sewer system?
- Radionuclides must be released in gaseous form only
- Concentrations must not exceed limits in Appendix B Table 3, and annual totals must not exceed specified limits (Correct answer)
- The local municipal authority must provide written approval
- The material must be non-radioactive as measured by a Geiger counter
Correct answer: Concentrations must not exceed limits in Appendix B Table 3, and annual totals must not exceed specified limits
10 CFR 20.2003 permits sewer disposal only when concentrations do not exceed Appendix B Table 3 limits and total annual quantities remain within specified thresholds.
Question 6: What is the correct classification for high-level radioactive waste (HLW) generated by commercial nuclear power plants?
- Class C low-level waste requiring engineered barriers at disposal
- Spent nuclear fuel and reprocessing waste requiring deep geological disposal (Correct answer)
- Transuranic waste managed at the WIPP facility
- Greater-than-Class-C waste managed at NRC-licensed sites
Correct answer: Spent nuclear fuel and reprocessing waste requiring deep geological disposal
Commercial spent nuclear fuel and reprocessing liquids are classified as HLW, requiring permanent disposal in a deep geological repository such as the proposed Yucca Mountain facility.
CHP CHP Radioactive Materials Handling & Waste Management 2
According to 10 CFR 61, into which categories is Low-Level Radioactive Waste (LLW) classified?