ML23240A511

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ROP Radiation Safety Brief Sep and Nov 2023 - Japan NRA Young Leaders
ML23240A511
Person / Time
Issue date: 08/28/2023
From: David Garmon-Candelaria, William Rautzen
NRC/NRR/DRA/ARCB
To:
References
Download: ML23240A511 (44)
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Text

Selected Topics in Radiation Safety Oversight and Licensing Bill Rautzen, Health Physicist David Garmon, Health Physicist Radiation Protection and Consequence Branch Division of Risk Assessment Office of Nuclear Reactor Regulation September 19, 2023 November 6, 2023 ML23240A511

Agenda

  • General Background information for how NRC completes its mission
  • Describe licensing functions as they relate to radiation safety
  • Describe how the U.S. NRC provides oversight of radiation safety at US NPP
  • Reactor Oversight Process
  • Inspection examples
  • Review some aspects of radiation monitoring at US NPP
  • Types of radiation monitoring
  • Roles and responsibilities
  • Data 2

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Background===

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NRR Letter dated October 15, 2019: https://www.nrc.gov/docs/ML1926/ML19260E683 NRC Values: https://www.nrc.gov/about-nrc/values.html 4

Key Day-to-Day Functions 5

Regulatory Hierarchy

  • Atomic Energy Act and Other Applicable Legislation
  • Plant-Specific Licensing Basis
  • Title 10 of the Code of Federal Regulations (CFR)
  • Operating License
  • Technical Specifications
  • Design Basis, Final Safety Analysis Report, Certain Commitments etc.

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Oversight Framework The regulatory framework for reactor oversight is a risk- informed, tiered approach to ensuring plant safety. There are three key strategic performance areas: reactor safety, radiation safety, and safeguards. Within each strategic performance area are cornerstones that reflect the essential safety aspects of facility operation. Satisfactory licensee performance in the cornerstones provides reasonable assurance of safe facility operation and that the NRCs safety mission is being accomplished.

Within this framework, the NRCs operating reactor oversight process provides a means to collect information about licensee performance, assess the information for its safety significance, and provide for appropriate licensee and NRC response. Because there are many aspects of facility operation and maintenance, the NRC inspects utility programs and processes on a risk-informed sampling basis to obtain representative information.

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Reactor Oversight Framework 8

Radiation Safety Cornerstones Occupational Radiation Safety - NRC regulations set a limit on radiation doses received by plant workers, and this cornerstone monitors the effectiveness of the plant's program to control and minimize those doses.

Public Radiation Safety - This cornerstone measures the procedures and systems designed to minimize radioactive releases from a nuclear plant during normal operations and to keep those releases within federal limits.

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Assessment of Performance 10

Communicating Significance Performance Indicators / Inspection Findings Green White Yellow Red Increasing Safety Significance Assessment of Performance - Action Matrix Columns Multiple/Repetitive Licensee Regulatory Degraded Unacceptable Degraded Response Response Performance Performance Cornerstone Increasing Safety Significance, Inspection, Management Involvement and Regulatory Action 11

Licensing 12

Licensing Insights

  • Through the licensing process, the U.S. NRC authorizes an applicant to conduct any or all of the following activities:
  • Construct, operate, and decommission commercial reactors and fuel cycle facilities.
  • Possess, use, process, export and import nuclear materials and waste, and handle certain aspects of their transportation.
  • Site, design, construct, operate, and close waste disposal sites.
  • To become licensed for any of these activities (or to amend, renew, or transfer an existing license), an entity or individual submits an application to the NRC.

The NRC staff reviews the submission, using standard review plans, to ensure that the applicant's assumptions are technically correct and that the proposed activities will not adversely affect the environment 13

Licensing Insights (contd)

  • Public process except for proprietary information
  • NRC approves the application (amends license, or provides authorization as applicable)
  • NRC does not advise or propose alternatives
  • Sometimes licensees supplement applications based on NRC questions
  • Typically done as a collaborative effort by the staff because different technical disciplines are involved
  • Project managers vs. Tech Staff
  • Examples of RP-related licensing actions
  • Request to commence/expand tritium production at a commercial nuclear power plant
  • Request for approval of changes to consensus standards referenced in the Technical Specifications (e.g., for worker qualifications)
  • Request for authorization to use certain types of respiratory protection (or different protection factors) 14

Radiation Safety Cornerstones 15

Performance Indicators

  • Keep occupational dose to individual workers below the limits specified in 10 CFR Part 20 Subpart C and
  • Use, to the extent practical, procedures and engineering controls based upon sound radiation protection principles to achieve occupational doses that are ALARA per (20.1101(b))
  • To assess the performance of the radiological effluent control program

Reference:

RIS 2000-08, IMC 0308, NEI 99-02, Rev 7 https://www.nrc.gov/reactors/operating/oversight/pi-summary.html 16

Occupational Radiation Safety PI

  • Unintended exposure occurrences Occupational Threshold: White Threshold: Yellow Threshold: Red Radiation Safety Performance Indicator Increased Required Regulatory Unacceptable Regulatory Response Band Performance Response Band Occupational >2 >5 Not Applicable Exposure Control Effectives 17

Public Radiation Safety PI

  • Sum of release occurrences per reactor unit that exceed the following:
  • Liquid: 1.5 mrem/qtr (whole body) or 5 mrem/qtr (organ) or
  • Gaseous: 5 mrads/qtr (gamma) or 10 mrads/qtr (beta) or 7.5 mrem/qtr (organ dose from I-131, I-133, H-3 and particulates)

Public Radiation Threshold: White Threshold: Yellow Threshold: Red Safety Performance Indicator Increased Required Unacceptable Regulatory Regulatory Performance Response Band Response Band RETS/ODCM >1 >3 Not Applicable Effluents 18

Inspections Types and Purpose

  • Types
  • Baseline inspections
  • Supplemental inspections
  • Generic safety issue, special and infrequent inspections
  • Objectives
  • To obtain factual information providing objective evidence that power reactor facilities are operated safely, and licensee activities do not pose an undue risk to public health and safety
  • To determine the causes of declining performance before such performance reaches a level that may result in undue risk to public health and safety
  • To identify those safety significant issues that may have generic applicability
  • Baseline: provide sufficient examination, along with PIs, that licensees are meeting the objectives of the ROP cornerstones 19

Inspection Areas IP 71124 Radiation SafetyPublic and 12/21/17 17-031 .docx Occupational IP 71124.01 Radiological Hazard Assessment and 12/29/21 21-041 .docx Exposure Controls IP 71124.03 In-Plant Airborne Radioactivity Control 12/23/19 19-042 .docx and Mitigation IP 71124.04 Occupational Dose Assessment 12/23/19 19-042 .docx IP 71124.05 Radiation Monitoring Instrumentation 03/04/20 20-014 .docx IP 71124.06 Radioactive Gaseous and Liquid Effluent 03/04/20 20-014 .docx Treatment IP 71124.07 Radiological Environmental Monitoring 03/04/20 20-014 .docx Program IP 71124.08 Radioactive Solid Waste Processing and 03/04/20 20-014 .docx Radioactive Material Handling, Storage, and Transportation https://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html 20

Inspection Finding Process 21

Significance Determination Performance Indicators / Inspection Findings Green White Yellow Red Increasing Safety Significance

  • Objectives
  • Characterize safety significance of inspection findings using best available Public Rad Safety SDP Occupational Rad Safety SDP info.
  • Provide an objective common Rad Material Effluents and ALARA Overexposure framework for communicating Control REMP significance Substantial Compromised Transportation Part 37 potential for ability to assess
  • Provide a basis for timely assessment overexposure dose and enforcement actions Land Disposal of Rad Waste

Follow-On Activities 23

Example: Inspection Finding

  • Event
  • At a pressurized water reactor facility (PWR Unit 1), several workers were internally contaminated when a licensee failed to adequately evaluate the radiological hazards involved with the installation of steam generator nozzle dams.
  • This resulted in the failure to adequately identify the presence of alpha emitting isotopes in the SG bowls in concentrations which caused a substantial potential exposure to workers in excess of applicable regulatory requirements.

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Example: Inspection Finding

  • Issue of concern identified when the workers reported to other plants (several days after the nozzle dam job at PWR Unit 1) and discrete radioactive particles were identified on their boots and clothing
  • The NRC conducted a special inspection (reactive inspection) and identified deficiencies in the licensees hazard control, survey and monitoring performance
  • Focus on the monitoring issue for this example
  • Licensee did not take adequate air samples and bioassay in order to determine exposure to workers
  • Inspection finding
  • Need to determine significance

Finding Identified ALARA No Planning or Work Controls?

Yes Is 3 Year Rolling Average Collective Dose

>135 person-rem/unit: PWR Or >240 person-rem/

Unit for BWRs?

Yes No No Actual Dose Greater than 4 Green

> 25 person-rem? Occurrences?

Yes Yes White 26

Was It An No Overexposure?

Yes Yes Was SDE > 5 Times SDE Exposure?

The Limit?

Yes No No White Was the Dose No Yellow

> 5 Times the Limit?

Yes Red 27

No Was There A Was the Ability No Substantial To Assess Dose Green Potential? Compromised?

Yes Yes SDE/DRP Exposure?

Yes Green No No Was It A Whole Body White Exposure in a VHRA?

Yes Yellow 28

Substantial Potential

  • An event presents a substantial potential when it was fortuitous that the resulting exposure or release did not exceed the limits of 10 CFR Part
20. The concern is not the significance of the resulting or potential exposure, but whether the licensee provided adequate controls over the situation, as required, to prevent exceeding the Part 20 limits. No credit is given for luck. When considering whether the circumstances of a particular case meet the threshold for escalated enforcement action for this example, the staff should attempt to construct a reasonable scenario in which a minor alteration of circumstances would have resulted in a violation of the Part 20 limits.
  • Circumstances such as (a) timing, (b) source strength, (c) distance, and (d) shielding should be considered.

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Radiation Monitoring 30

General

  • Occupational
  • Personnel Monitoring
  • Surveying
  • Public
  • Effluent Monitoring
  • Environmental Monitoring 31

General Requirement to Survey 32

Monitoring Occupational Exposure 33

Occupational Monitoring/Survey Equipment 34

Effluents & Environmental Monitoring Laws

  • Atomic Energy Act (AEA) of 1954 (as amended)
  • Clean Air Act (CAA) of 1970
  • Safe Drinking Water Act (SDWA) of 1974
  • Resource Conservation and Recovery Act (RCRA) of 1976
  • Department of Energy Organization Act of 1977
  • Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980
  • Nuclear Waste Policy Act of 1982
  • Energy Policy Act (EPAct) of 2005 35

Effluents - Types

  • 3 Types
  • Liquid
  • Gaseous noble gas
  • Gaseous particulate radionuclides (e.g., iodine)
  • We are also concerned with direct radiation but it is not formally considered an effluent in our regulations
  • Addressed in plant Technical Specifications
  • Must be monitored if the direct radiation from the plant is greater than background 36

Effluent Monitoring Equipment Particulate-Iodine-Noble Gas Monitor (Mirion)

On-Line Process Monitor (Canberra) Adjacent-to-Line Detector (General Atomics) 37

Environmental Monitoring

1. Survey the radiological conditions in the vicinity of the facility before initial reactor operation to establish the baseline radiological conditions in the local environment.
2. Measure the levels of radiation and radioactive materials in the local environment during the lifetime of the facility.
3. Determine if any measurable levels of radiation or radioactive materials in the local environment are attributable to plant operation.
4. Determine if measurable levels of plant-related radiation and radioactive materials in the local environment are commensurate with the radioactive effluents and plant design objectives (e.g., as low as reasonably achievable).
5. Report measurement results, summaries, and trends regarding radiation and radioactive materials in the local environment.
6. Maintain the REMP by identifying changes in land use (e.g.,

agricultural land use in unrestricted areas) that may impact the measurements or measurement results associated with exposure pathways identified in the REMP.

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Example - Environmental Monitoring Program

  • Approximately 18,500 people live within 10 miles of the WBN site, with 80% of people living within 5-10 miles. Two small towns are located in this area: Spring City (northwest of the site; pop. 2,200) and Decatur (south of the site; pop. 1,500). The area 10-50 miles from the site includes portions of the cities of Chattanooga (southwest of the site; pop.

170,000) and Knoxville (east by northeast of the site; pop. 185,000)

  • Radiation levels are measured by collecting samples within the vicinity of the plant, including air, water, food crops, soil, fish, and shoreline sediment, and by direct (i.e.,

external) monitoring.

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Example - Direct Radiation Monitoring Program

  • The monitoring locations are grouped according to the distance from the plant.
  • The first group consists of all monitoring points within 2 miles of the plant (onsite)
  • The second group comprises all locations greater than 2 miles from the plant (offsite)
  • The average quarterly and annual gamma radiation levels determined from the dosimeters deployed around WBN in 2018 are summarized in Table 1 40

Requirements and Key Guidance

  • Requirements: 20.1302, 50.36a, Technical Specifications

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Effluent and Environmental Reports https://www.nrc.gov/reactors/operating/ops-experience/tritium/plant-info.html 42

Discussion/Questions william.rautzen@nrc.gov david.garmon@nrc.gov 43

Key References

  • IMC 0305 - Operating Reactor Assessment Program: Overview of the assessment process/performance reviews, explanation of the Action Matrix
  • IMC 0309 - Reactive Inspection Decision Basis for Reactors: Describes criteria for reactive inspections (e.g., SIT)
  • IMC 0612 - Issue Screening: Guidance for dispositioning of NRC findings, more-than-minor examples
  • IMC 2515 - Light Water Reactor Inspection Program Operations Phase
  • Federal Register Notices associated with key regulations 44
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