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Radiological Work Controls

Radiological Work Controls

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Radiological Work Controls

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  1. RadiologicalWorkControls HPT 001.116

  2. TERMINAL OBJECTIVE • Upon completion of this course, the participants will demonstrate their knowledge and understanding of the information presented during RADCON Technician training by obtaining a score equal to or greater than 80% on a written examination. The information presented in this lesson plan may be part of an overall exam or be the only information for which the student is examined.

  3. ENABLING OBJECTIVES • Standards and conditions apply to all enabling objectives. They include under the examination ground rules, without the use of training materials or outside assistance, and utilizing information presented in this lesson plan. Upon completion of this lesson each participant will be able to:

  4. ENABLING OBJECTIVES • State the purpose of the ALARA Preplanning Report (APR). • Explain the necessity for a radiological pre-job briefing for the APR/RWP. • Determine when a waiver of the APR/RWP applies. • Identify the posting requirements in terms of radiation levels for high radiation areas, very high radiation areas and locked high radiation areas.

  5. ENABLING OBJECTIVES • Explain the controls for entry to containment at power. • Explain the administrative control of keys for entry into locked high radiation areas. • Explain the method of control of areas subject to varying dose rates. • Explain the workers responsibilities for entering high radiation, very high radiation and locked high radiation areas.

  6. ENABLING OBJECTIVES • Explain the RADCON specialists’ responsibilities for entering high radiation, very high radiation and locked high radiation areas. • State the actions and precautions to be taken during a resin transfer. • Determine the correct methods for ensuring diver protection from radiation hazards.

  7. ENABLING OBJECTIVES • State the precautions and steps to be taken during a steam generator entry including calculation of stay times. • Determine the correct steps to be taken when work is performed in the fuel transfer canal.

  8. Introduction • Many of the tasks that a RADCON technician performs can be considered routine. This lesson will explain some of the precautions that a RADCON technician should take when performing specialized tasks. In these cases, additional human performance measures should be taken when performing these special tasks. The possibility for unnecessary exposure to radiation exists in all tasks the technician performs but it is greater when these specialized tasks are performed. • The technician should always use the 2 minute rule when performing any of these tasks. Peer checking may also prevent any unacceptable conditions from occurring.

  9. ALARA Preplanning Reports (APR) Obj. 1 • The purpose of the APR is to ensure that ALARA considerations are included into a Radiation Work Permit (RWP) through the use of protective requirements and special instructions. • Required for each job where collective TEDE is expected to exceed 1 person-rem.

  10. ALARA Preplanning Reports (APR) • Pre-job planning is an integral part of a RWP. • Approval requirements vary from site to site in TVAN.

  11. ALARA Preplanning Reports (APR)Obj. 2 • The responsible supervisors/work directors ensures all personnel are briefed on the applicable work procedure, RWP protective requirements and special instructions, radiological hazards and APR considerations prior to starting the work.

  12. ALARA Preplanning Reports (APR)Obj. 3 • During an emergency, ALARA preplanning may be waived by the RADCON Shift Supervisor. This waiver shall be noted in the RADCON Log. After the emergency has been resolved, a waiver shall be completed and forwarded to the ALARA representative.

  13. ALARA Preplanning Reports (APR) • Areas in the plant/work area that have dose rates significantly lower than the work area shall be marked as an ALARA Zone. An ALARA Zone is a low dose waiting area. Workers should be encouraged to use these areas when there is a delay in work and exiting the area is not feasible.

  14. ALARA Preplanning Reports (APR) • ALARA pre-job planning shall be carried out to identify and minimize the hazards associated with jobs involving potentially significant radiological hazards identified for each job.

  15. Posting Requirements Obj. 4 • High Radiation Areas • ≥ 100 mrem/hr but < 1000 mrem/hr at 30 cm. • Post as close to the source as possible. • Barricaded. Head high posting or swing gates for entrances.

  16. Posting Requirements Obj. 4 • Locked High Radiation Areas • > 1000 mrem/hr at 30 cm & < 500 rads at 1 meter in 1 hour. • Physically barricaded and locked. • Flashing light or guard required for areas that can not be locked.

  17. Posting Requirements Obj. 4 • Very High Radiation Areas • > 500 rads at 1 meter in 1 hour. • Physically barricaded and locked. • Flashing light or guard required for areas that can not be locked.

  18. Entry to Containment at Power Obj. 5 Controls • Inside the polar crane wall (IPCW) and in the fan rooms, posted and treated as a locked high radiation area. • Outside the polar crane wall (OPCW) is posted as a high radiation area. • Double locked (RADCON has the keys).

  19. Entry into Locked High Radiation Areas Obj. 6 Keys • All areas have different keys. • Controlled by RADCON. Shift Manager & RADCON Shift Supervisor have master key. • Key inventory process - sign in and out. • Must verify each shift that all are locked. Human Performance Error Prevention Tools: Self Checking Peer Checking

  20. Signs and Barriers • Placement • Accessibility, room size and other variables will impact the way areas are posted. • Post as close as possible to the source. When in doubt, be conservative and discuss with your Shift Supervisor.

  21. Signs and Barriers High Radiation Areas • Rope barrier Locked High Radiation Area • Permanent barrier that blocks accessibility • Flashing Lights

  22. Signs and Barriers Very High Radiation Areas • Access requires plant management approval • SOS has master key.

  23. Control of Areas Subject to Varying Dose Rates Obj. 7 • Areas/systems of concern • Tanks - can change with tank level (will be marked). • Systems - can change with system operation (will be marked).

  24. Control of Areas Subject to Varying Dose Rates Obj. 7 • Methods of Control • Continuous coverage • Electronic alarming dosimeter • Use of area radiation monitors in lower dose areas.

  25. Workers Responsibilities to Comply with the RWP Obj 8 High Radiation Areas • Check with RADCON prior to entry. • Pre job briefing by foreman. • Must have a bonafide need to enter.

  26. Workers Responsibilities to Comply with the RWP Obj 8 Locked High Radiation Areas • Check with RADCON prior to entry. • Pre job briefing by RADCON & foreman. • Must have a bonafide need to enter.

  27. Workers Responsibilities to Comply with the RWP Obj 8 Locked High Radiation Areas • The responsibility for closing and locking the door is with the person who checks out the key. • RADCON ensures that all barriers are locked. • Continuous RADCON coverage is required.

  28. Workers Responsibilities to Comply with the RWP Obj 8 Very High Radiation Areas • Plant Manager approval for entry. • RADCON Manager approval for entry. • Check with RADCON prior to entry. • Pre job briefing by RADCON & foreman.

  29. Workers Responsibilities to Comply with the RWP Obj 8 High Radiation Areas • Must have a bonafide need to enter. • The responsibility for closing and locking the door is with the person who checks out the key. • RADCON ensures that all barriers are locked.

  30. RADCON Technicians Responsibilities Obj 9 • High Radiation Areas • Locked High Radiation Areas • Very High Radiation Areas Human Performance Error Prevention Tools: Self Checking Peer Checking and Two Minute Rule (as time permits)

  31. RADCON Technicians Responsibilities Obj 9 • RADCON personnel shall have the authority and responsibility to stop work or prevent the initiation of a job, test or work activity when, in their judgment, the radiological conditions warrant such an action or continued performance of the work would result in the violation of regulation, policy or plant procedures and such actions are consistent with plant safety. RADCON personnel shall immediately inform the Shift Manager and RADCON Superintendent of their actions.

  32. Spent Resin Transfers Obj 10 • Work activities will be restricted in affected areas until the spent resin transfer is complete and surveys have been conducted to establish radiological conditions and controls. • When resin is transferred, affected systems and areas are locked or guarded and properly posted based on the anticipated radiological conditions as determined by RADCON and RADWASTE. • Post transfer surveys should be performed to ensure there are no hot spots remaining. Human Performance Error Prevention Tools: Self Checking, Peer Checking and Two Minute Rule (as time permits)

  33. Diving Operations Obj 11 • Prior to diving operations, a detailed survey shall be conducted in the work area and areas where the diver will be going including the descent area. • The survey should be conducted using two independent radiation monitoring devices. • If any operation is conducted that could cause the movement of contaminated particles or could cause significant changes in the dose rate, a new survey shall be conducted. Any surveys conducted after the start of the dive shall be reviewed with the diver(s).

  34. Diving Operations Obj 11 • Surveys results shall be discussed with the diver and all personnel involved with the dive as part of a pre-dive briefing. The diver shall also be cautioned not to pick up any blackened, battered or unidentified items (foreign material) since they could be irradiated. Irradiated objects shall be surveyed and then moved to safe storage by remote handling methods. • The diver shall be equipped with telemetric dosimetry. In addition, the diver should be tethered.

  35. Diving Operations Obj 11 • The diver should be sprayed with clean demineralized water prior to entering the pool to pre-soak the suit and equipment, thus minimizing contamination on the suit. • Shielding or physical barriers may be used to minimize exposure and mobility to non-surveyed areas. • Surveys of the water surface should be performed during the dive.

  36. Diving Operations Obj 11 • The diver should be sprayed with clean demineralized water when exiting the pool to minimize contamination spread. • Survey the diver after exiting the pool for hot particles. • If the tritium concentration exceeds 0.01 µCi/ml in the water, then a urinalysis bioassay should be performed on the diver(s) before the initial dive, at prescribed intervals during the dive and after the dive.

  37. Steam Generator Entry Obj. 12 • Telemetric dosimetry should be used when individuals enter a steam generator. If it is not available, a stay time determination should be made. This is done prior to the entry and reevaluated after each entry. • Stay times may be determined using the following method: • Stay time (minutes) = __dose limit (mrem)___ x 60 minutes/hr dose rate (mrem/hr) • Other methods may be utilized which incorporate TLD measurements.

  38. Steam Generator Entry Obj. 12 • Entries into steam generators should be documented • Survey all material and debris removed from a steam generator. Use remote handling tools to handle highly radioactive material. CAUTION: Highly radioactive material may be present in the steam generator and caution should be used when removing or handling this material.

  39. Fuel Transfer Canal Entry Obj. 13 • RADCON will provide coverage of all activities conducted in the transfer canal. • Prior to entry, a detailed survey of the work areas and traverse areas will be performed. • Any operation which could significantly affect the dose rates or require entry into areas not previously surveyed, RADCON must survey prior to work proceeding. • Survey results must be discussed with workers prior to entry.

  40. Fuel Transfer Canal Entry Obj. 13 • Workers shall be cautioned not to pick up any blackened, battered or unidentified items (foreign material) since they could be irradiated. • Additional dosimetry (TLD location, extremity or multi-badging or remote monitoring) will be determined based on survey results. • The transfer canal should be covered while draining to prevent the spread of contamination particles. If this isn’t practical, other engineering controls should be used (use of HEPA units, frequent rinsing of canal walls, decontamination).

  41. Summary RADCON Specialists must be aware that specialized jobs call for extraordinary measures to ensure that the workers involved are protected from the harmful effects of ionizing radiation. The control of radiological work is paramount in ensuring that this occurs. Using the Human Performance tools as well as the skills acquired during training and the in-plant phase will help aid the Specialist in providing this protection..

  42. The End