ML19305C587
| ML19305C587 | |
| Person / Time | |
|---|---|
| Issue date: | 10/08/2019 |
| From: | Jason Vonehr NRC Region 4 |
| To: | |
| Shared Package | |
| ML19305C662 | List: |
| References | |
| Download: ML19305C587 (42) | |
Text
U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment Regulatory Inspections Jason vonEhr Health Physicist USNRC Region IV 8 October 2019
Objectives for Regulatory Inspection Presentation
- To provide the basis for NRCs inspection program
- To introduce the guidance and implementing documents
- To review the typical radioactive sources in use
- To identify the challenges and approaches to well logging inspections 2 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
NRC Implementing Document Inspection Manual Chapter 2800
- Materials Inspection Program
- Groundwork of the NRCs material inspection program - not limited to well logging
- Performance-Based Inspections vs Compliance-based Inspections
- unannounced inspections
- Observation of licensed activities
- Reactive vs Routine
- Field vs Main Office 3
NRC Guidance
- NRC Guidance for Licensing/Use
- NUREG-1556, Volume 14, Rev 1: Consolidated Guidance About Material Licenses, Program Specific Guidance about Well Logging, Tracer, and Field Flood Study Licenses
- NRC Inspection Manual
- Inspection Procedure 87123: Well Logging Programs
- Inspection Procedure 87137: 10 CFR Part 37 Materials Security Programs 4 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Well Logging Operations Drill-to-Stop - Well logging operation that requires all drilling operations to cease and requires that parts of the drilling apparatus are removed to provide access to the well bore. The well logging tool is then lowered into the well bore to obtain information.
Measurement While Drilling (MWD or LWD) - Well logging operations that occur during the drilling of the well bore and do not require that the drill stem or other equipment be removed from the well. This type of operation requires that the well logging tool contain one or more sealed sources and be located above the drilling stem to obtain information through mud telemetry communications.
5
Typical Sealed Sources in use
- Tools often use one or more of the following:
- Cs-137
- H-3
- Co-60
- Co-60 is used in pipe collar markers &
subsidence or depth control markers
- Depleted uranium (DU) can be used as a weight in sinker bars to pull a logging tool to the bottom of the well 6 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Sources - Radioactive Markers
- Licensed material used for depth determination or direction orientation, such as radioactive collar markers &
radioactive iron nails (10 CFR 39.47)
- The quantities shall not exceed § 30.71 (Exempt) & are only subject to § 39.37 (Inventory)
Small Metal Beads or Metal Strips Iridium-192 (10 µCi)
Cobalt-60 (1 µCi) 7
Other Types of Services
- Tracer studies - unsealed RAM (liquid, gas or solid) is injected into a well bore/underground reservoir to monitor movement of fluids & gases; the logging tool (detector) is lowered down to detect injected isotopes &
use the data to analyze the formation
- The tracer survey uses techniques similar to gamma ray spectroscopy to ID the distribution & placement of the tagged materials
- Common isotopes: iodine-131, iridium-192, scandium-46, antimony-124
- Chosen for (relatively) short lived half-lives, distinct gamma spectra, and commercial availability 8 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Examples of Tracer Studies
- Field flood studies & oil and gas recovery studies - performed to investigate direction & flow rate of oil & water; radioisotopes are injected into multiple wells, then oil/gas samples are collected & analyzed
- Gas (H-3, Kr-85, Br-82, C-14, I-131)
- Liquid (H-3, C-14, Na-22, S-35, Ca-45, Co-60, Ni-63, Zn-65, Sr-85, Sc-46, Sr-90, Ag-110m, I-125, I-131, La-140, Ir-192)
- Labeled frac sands - Liquid or solid RAM chemically bonded to glass or resin beads are injected into a well in a density-controlled solution; the sands distribution within the formations fractures is assessed with a well logging tool (detector) lowered into the geologic formation following injection
- Ag-110m, Br-82, Ir-192, Sb-124, Sc-46 9 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Tracer Studies Contd Well Logging Tracer Applications Common Isotopes for Tracer Studies Gas H-3, C-14, Kr-85, Br-82, I-131, I-125 Liquid H-3, C-14, Na-22, S-35, Ca-45, Co-60, Ni-63, Zn-65, Sr-85, Sc-46, Sr-90, Ag-110m, I-125, I-131, La-140, Ir-192, Fe-59, Sb-124, Au-198, Ag-110m Labeled Frac Sand, Sc-46, Br-82, Ag-110m, Beads, Resin Sb-124, Ir-192 10
INSPECTIONS 11 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Prior to Performing an Inspection
- Know the rules/regulations related to well logging.
- 10 CFR Parts 19, 20, 21, 30, (37), 39, 71, (or Agreement State Equivalent) and 49 CFR
- Understand license authorizations and commitments
- For temporary job sites: have the appropriate Personal Protective Equipment (PPE), radiation instrumentation, and any additional items such as wipes, gloves, etc.
- For previous inspection findings review corrective actions and long term measures implemented to prevent recurrence.
- Understand the licensees file: previous inspection findings, any license amendments, or pending requests since at least the last inspection 12 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Inspection Planning
- Main Office vs Temporary Job Site
- Temporary Job Site
- May be announced through oil/gas operator (client)
- Preference should always be unannounced (at least with the licensee) when practicable
- Ensure the inspector is prepared (PPE may include:
Steel-toed boots, Nomex, hard hat, safety glasses, ear plugs/hearing protection)
- Central Office
- Much easier, but less indicative of the level of radiation safety and security than in the field 13
Job Site Considerations
- Remote job site locations, sometimes hours or days away from central office
- Job site location access controls; many oilfields require a safety escort
- The lack of appropriate and required PPE may lead to the inspector not being allowed access to the well logging operation (i.e. no steel toe boots)
- Unanticipated adverse weather conditions 14 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Job Site Inspection Protocol
- Oil/gas operator authorization
- Inspectors own PPE: PERSONAL SAFETY IS INSPECTORS RESPONSIBILITY
- Extended onsite time
- Oil/gas operators assistance
- The inspector SHOULD NOT be a nuisance- stay out of the way
- If practicable: inspector should be onsite prior to logging rig-up
- Ensure licensee performs proper radiation surveys
- For post-tracer operations: survey above and around well head
- Conduct licensee interviews when time permits (safety culture, field experience, what-if scenarios, etc.)
- Inspection debrief with oil/gas operator (they always want to know the results) 15 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Jobsite Inspection - What to Review First?
- There are many items to review & observe, but they fall basically into three areas:
- Observation of activities & conducting surveys of the site
- Emphasis is on Performance Based Inspection
- Interviews with site personnel (licensee & non-licensee)
- Assess licensee personnels training and experience
- Reviewing the paperwork (performance based vs. compliance based) 16 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
RECORDS REQUIRED AT TEMPORARY JOB SITES BY NRC
- Operating and Emergency procedures
- Evidence of radiation survey instrument calibration
- Radiation survey records
- Shipping papers
- Copy of License (State or NRC) 17 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
NRCs Oversight Offshore
- NRC Memorandum of Understanding with BSEE -
Bureau of Safety and Environmental Enforcement
- BSEE offers logistical support to NRCs oversight of offshore Gulf of Mexico
- For reasons of employee safety and legal restriction (lack of an equivalent memo with BSEEs other regions) the NRC does not conduct inspections offshore in Alaska and Pacific Regions 18
ACCIDENTS/EVENTS 19 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Factors Contributing to Accidents Understand why accidents can occur when performing well logging activities LACK OF USE OF LACK OF SURVEY METER REGULATORY CONTROL EQUIPMENT ACCIDENT POOR OR FAILURE NO TRAINING NOT FOLLOWING INADEQUATE OR MISSING SAFETY POCEDURES SAFETY PROGRAM 20
Accidents Involving Well Logging Examples of potential accidents in well logging
- Source stuck down well (common)
- Lost (misplaced) source during/after well logging
- Lost or stolen source (in storage or transport)
- Physical damage (during fishing operations)
- Transportation accident
- Suspected exposure of persons
- Leaking source 21 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Source Abandonment Procedures
- 10 CFR 39.15(a)(5) or equivalent State regulation requires the following to be implemented within 30 days:
- Each irretrievable well logging source be immobilized and sealed in place with a cement plug
- A means shall be in place to prevent inadvertent intrusion on the source (i.e. whipstock or deflection device)
- A permanent identification plaque must be mounted at the surface of the well which contains the word CAUTION, the radiation symbol, date of abandonment, name of well owner and well, radionuclide and activity, depth of source and plug, and a warning to not re-enter the well.
22 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Source Abandonment
- Reporting Info 23
Reporting Challenges for Abandonment
- GPS location of
- Well head
- Site of Drilling equipment (offshore)
- Geographic location of sources
- True Vertical Depth
- Measured Depth 24
Abandoned Source Plaque 25
Accidents Involving Well Logging 26
2002 Augmented Inspection Team (AIT)
- U.S. NRC NUREG-1794
- Source lay unshielded on the drill rig floor for 2 days exposing 31 members of the public
- Direct cause: Failure of logging engineer to properly transfer the source to its transport container immediately after removal from tool
- Contributing causes: Failure to perform required radiation surveys; false indication of plug assembly
- Root cause: Failure to adequately investigate precursor events (six similar events occurred from 1987 and 2001, and only the direct, not root cause of each event was addressed) 27
Oklahoma City Event
- In February 2007, a logging crew failed to properly transfer cesium source from storage area to the transport container
- A mechanic (member of the public) found the source and put it in his jacket pocket, and wore this jacket for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, while visiting 5 commercial stores/offices
- The next morning, the logging crew realized that they didnt have their cesium source. They found it still in the mechanics jacket pocket, which was hanging up in his office.
- The dose estimates to the mechanic were 1 to 5 rem whole body exposure, and 18 Gray (1800 rads) shallow dose equivalent 28
Oklahoma City Event
- Causes of the event:
- Radiation surveys of the transport container were not performed after loading the source
- Vehicle surveys were not performed, even though the Shipping Certificate said that they were performed
- The logging supervisor had not received refresher radiation safety training in 2002, 2003, 2005, and 2006; the logging assistant had not had this training the year prior to the event (2006) 29 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Accidents Involving Well Logging
- Source:
Am-Be (200 GBq)
Description:
Source destroyed during recovery operation 30
Event Involving Tagging Ops
- Source:
Ir-192, Sc-46, Sb-124
Description:
- Portal Alarm at landfill - initiates NRC inspection.
- Logging Client had disposed of drilling cuttings, which included trace quantities of licensed material from tracer operations.
- Trace occurred at one well between July 27 and August 9, 2014, and a second well on August 17 and September 3, 2014
- Well completed, and subsequent (attempted) disposal occurred November 7, 2014, and December 16, 2014, respectively
- 53 additional Vac-boxes generated, 48 of which >10 pCi/gram tracer isotopes, 9 > 100 pCi/g, and 1 containing 842 pCi/g 31 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Event Involving Tagging Ops 32
PHOTO TOUR 33 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Well Logging Sealed Sources Cs-137 Am-241:Be 34
Neutron Accelerator Tube Tritium (D-T fusion reaction)
- Can work as neutron activation analysis; neutrons emitted from tube bombard atoms in the formation, which emits gamma rays through activation or inelastic collisions. The gamma rays are detected by logging tool.
- Can work as neutron moderation analysis; neutron emitted are moderated or thermalize (slow down) in the formation, a fraction of which will be captured by the detector. This allows analysis of, among other things, hydrogenous content of the formation (difference between water and oil/natural gas) 35
Typical well logging truck, Prepping for work at a TJS 36 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
The Olympic Torch run to the platform 37
Conventional Tracer Studies Tracer Transport Tracer Pumps Container Radiation Survey Meter at Tracer Distribution Junction before entering Well 38
Field Flood Studies 39
Tracer Studies - Frac Site View Frac Pumps Missile Well-head Missile 40
Objectives for Regulatory Inspection Presentation
- To provide the basis for NRCs inspection program
- To introduce the guidance and implementing documents
- To review the typical radioactive sources in use
- To identify the challenges and approaches to well logging inspections 41 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment
Questions?