ML18011A278
| ML18011A278 | |
| Person / Time | |
|---|---|
| Issue date: | 01/10/2018 |
| From: | David Garmon-Candelaria NRC/NRR/DRA |
| To: | |
| Garmon-Candelaria D | |
| References | |
| Download: ML18011A278 (14) | |
Text
ALARA from a Regulatory Perspective January 9, 2018 David Garmon Health Physicist Radiation Protection and Consequence Branch Division of Risk Assessment Office of Nuclear Reactor Regulation United States Nuclear Regulatory Commission
Regulatory Framework Licensees shall use, to the extent practical, procedures and engineering controls to achieve occupational doses that are ALARA (10 CFR 20.1101)
For occupational ALARA programs
- Compliance is judged on whether the licensee has incorporated measures to track and if necessary to reduce exposures not whether exposures represent absolute minimum (56 FR 23360, May 21, 1991)
NRC oversight is performance-based and risk-informed
- What is Reasonably Achievable?
- Collective dose is factored into evaluation of occupational ALARA programs under the Reactor Oversight Process (ROP)
Slide 2 of 13
U.S. Commercial LWR Collective Dose 1974 - 2016 Slide 3 of 13 2016 Collective Dose (person-rem)
BWR:
98 PWR:
31 Average:
54
Average Measurable Dose per Worker 1974 - 2016 Slide 4 of 13
- Not adjusted for transient workers.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Average Measurable Dose (rem)
Year Average Measurable Dose per Individual*
BWR PWR LWR 2016 Average Measurable Dose (mrem)
BWR:
107 PWR:
72 Average:
90
Average Number of Workers with Measurable Dose 1974 - 2016 Slide 5 of 13 2016 Avg. # of Individuals with Measurable Dose BWR:
921 PWR:
432 Average:
600
Oversight of Occupational ALARA ALARA Planning is an Inspectable Area under the ROP Inspection Procedure 71124.02 (revised Jan. 2018)
- Radiological Work Planning
- Verification of Dose Estimates
- Implementation of ALARA Work Controls
- Radiation Worker Performance
- Problem Identification and Resolution Industrywide data is used to develop plant-specific, three year averages for collective dose and to develop dose quartiles
- Guides planning of inspection efforts
- Used in assessment of inspection finding significance Slide 6 of 13
ALARA Inspections Inspection effort generally determined by licensee quartile standing
- Also consider scope of radiological work and trends
- IP 71124.02 (revised Jan. 2018) biennial hours range from 32 to 60 (average 46)
- Licensees in lowest dose [highest dose] quartile should get the minimum [maximum] inspection effort
- Licensees in middle two quartiles should get 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br /> (adjusted for effectiveness of ALARA and source-term-reduction efforts)
Plant-specific, three year average is used to assess significance of ALARA Findings Slide 7 of 13
ALARA Issue Screening ALARA Findings: More-than-Minor, performance deficiencies that concern unplanned, unintended occupational collective dose resulting from a deficiency in ALARA planning or work control (IMC 0609 App C)
Performance Deficiency: Failure to meet a requirement or self-imposed standard where the cause was reasonably within the licensees ability to foresee and correct; and thus prevent (IMC 0612)
Minor vs. More-than-Minor Unplanned, Unintended Collective Dose
>5 person-rem More-than-Minor (Inspection Finding)
Unplanned, Unintended Collective Dose
>50% of the planned dose Performance Deficiency Minor (Address with CAP)
Yes No No Yes Yes Slide 8 of 13
ALARA Significance Determination Process If plant-specific, three year average is threshold, significance of ALARA finding is assessed to be Green (IMC 0609)
- Boiling Water Reactor: 240 person-rem
- Pressurized Water Reactor: 135 person-rem If plant-specific, three year average is > threshold, consider the magnitude of the issue and collective dose associated with recent issues
- Magnitude of issue: Did actual dose exceed 25 person-rem?
- No, then a Green finding
- Yes, then a White finding
- Consider recent issues: Were there more than 4 occurrences where actual dose > 5 person-rem and > 50% above dose estimate?
- No, then a Green finding
- Yes, then a White finding Slide 9 of 13
Boiling Water Reactor Quartiles BWR Quartiles Plant Three Year Collective TEDE per Reactor Year 2014-2016 (person-rem) 1st Quartile Top 50 Bottom 72 2nd Quartile Top 78 Bottom 110 3rd Quartile Top 110 Bottom 133 4th Quartile Top 142 Bottom 201 (IMC 0609 threshold is 240)
Average per Reactor-Year 110 Slide 10 of 13
Pressurized Water Reactor Quartiles PWR Quartiles Plant Three Year Collective TEDE per Reactor Year 2014-2016 (person-rem) 1st Quartile Top 20 Bottom 30 2nd Quartile Top 30 Bottom 38 3rd Quartile Top 39 Bottom 46 4th Quartile Top 47 Bottom 241 (IMC 0609 threshold is 135)
Average per Reactor-Year 42 Slide 11 of 13
How to Give us Feedback Slide 12 of 13 Inspectors Conferences Reactor Oversight Process Monthly Public Meeting Write a Letter
- Raise an Issue
- Request a Meeting Public Comment Periods on Published Documents
Questions and Discussion Slide 13 of 13 david.garmon@nrc.gov (301) 415 - 3512
Slide 14 of 13 Regulatory Panel