6.0 INTERNAL EXPOSURE TO RADIATION
6.1 Requirements
CNS radiation protection procedures have been developed in accordance with 10 CFR 20.
6.1.1 Regulations
Internal radiation exposure shall be maintained within the limits of 10 CFR 20 which specifies the Derived Air Concentrations (DAC) of radioactive materials in the air for restricted areas (occupational exposure) and unrestricted areas (non-occupational exposure).
6.1.2 Administrative Control Limits
Consistent with the project's commitment to the ALARA concept, administrative control limits are established to prevent inadvertent overexposure, and to serve as an action level for implementing engineering controls, administrative controls, and personal protective measures. Administrative control limits for airborne concentrations of radioactive materials shall be set at 30% of the applicable DACs. Areas that exceed the control limits shall be posted as Airborne Radioactivity Areas in accordance with the prescribed posting procedures. Engineering and/or administrative controls shall be implemented, as practical, to reduce the airborne concentrations of radioactive materials to below the control limits. When such controls are not feasible or are ineffective in reducing the concentrations to below the control limits, the use of respiratory protection equipment shall be instituted to ensure that personnel exposures do not exceed 12 DAC-hrs per month.
6.1.3 Bioassay Samples
Bioassay urine samples will be required of CNS and subcontractor personnel at the beginning, end, and at other times during the project as deemed necessary by the CHP and CNS-HP. Fecal samples may be required on a routine or periodic basis. If airborne radioactivity is detected from a grab sample, either high or low volume, personnel sampler or from the environmental samplers the requirement for a fecal sample will be made based on the degree of the impact of the results. Other indicators will be evaluated on an as needed basis. The CHP will administer this program. The CNS-HP shall be notified immediately of positive bioassay results. Results of bioassay analysis shall be provided to the employee upon written request.
6.2 Respiratory Protection
In order to minimize the potential for an internal uptake of radioactive material, respiratory protection will be evaluated and provided as needed. When needed, air sampling and required respiratory protection will be specified in the RWP. Full-face negative pressure respirators or powered air purifying respirators with HEPA filters will be the first choice for personnel protection in areas with high airborne radioactivity.
If air samples indicate airborne contamination levels are sufficiently high, Level B personal protective equipment will be used for work in the affected areas. It is extremely unlikely that Level B protection will be required due to radiological hazards. If air samples indicate airborne contamination levels are sufficiently low, removal of respiratory protection will be proposed and approved by the CNS-HP. HEPA-Filter equipped ventilators and vacuum cleaners will be used as necessary to aid in minimizing airborne radioactivity.
7.0 CONTROLLED ACCESS AREAS
Controlled access areas are established for the purpose of controlling radiation exposures to site workers, visitors, and the general public.
7.1 Definitions of Controlled Access Area
The Controlled Access Area (CAA) is that area to which entry is regulated to prevent unnecessary radiation exposure. The CAA may include the following designated areas:
7.1.1 Restricted Area
Restricted areas are those areas in which health physics monitoring and dosimetry are required. These areas may be fenced or roped off and will be posted. The site support offices will be segregated from the restricted areas to limit workers exposure from the radiation areas.
7.1.2 Clean Areas
Clean areas are those areas in which radioactive material is not present in quantities large enough to warrant radiation protection practices. Areas outside the restricted areas are considered "clean areas." In addition, certain areas within the restricted area may be designated as "clean areas." The site support area will also be a clean area.
7.1.3 Radiation Area
A radiation area is any area, accessible to individuals, in which an individual could receive a radiation dose in excess of 5 mrem in one hour, but less than 100 mrem in one hour, at 30 cm from the radiation source (or from any surface through which the radiation penetrates). This area is synonymous with and may be called a Radiation Controlled Area (RCA). Radiation areas shall be posted in accordance with 10 CFR 20.
7.1.4 Airborne Radioactivity Area
Airborne radioactivity area is any area in which the concentration of airborne radioactive materials exceeds 30% of the DAC. These areas will be posted as airborne radioactivity areas.
7.2 Controlled Access Area Entry Requirements
CNS refers to the access/egress point of a restricted area/exclusion zone as a controlled access area (sometimes called "control point"). This type of area is also called a "Contamination Reduction Zone" (CRZ).
Personnel entering the controlled access area shall have received radiation safety training or shall be escorted by personnel that have received the training. Individuals entering the controlled access area shall read and sign the RWP, which acknowledges their understanding of and adherence to the requirements set forth in that document. Site workers entering the controlled access area shall wear the dosimetry devices assigned to them by CNS. Visitors to the site will not be required to wear a dosimetry device unless they are required to enter a restricted area.
There shall be no eating, drinking, smoking, or chewing allowed within the controlled access area except in designated "clean" areas.
The need for respiratory protection shall be evaluated and documented for personnel entering an Airborne Radioactivity Area.
Personnel and equipment/material leaving the restricted area shall be surveyed for radioactive contamination at the control point prior to exiting the area.
7.3 Clean Area Requirements
Clean areas should be surveyed for radioactive surface contamination at a minimum of once per week. Clean areas will be promptly decontaminated if surface contamination levels exceed administrative values.
8.0 TRAINING REQUIREMENTS
8.1 Discussion
Training is one of the most important elements in an effective radiation protection and ALARA program. The amount and type of training depends upon the individual's work assignment. Radiological Training shall be performed per the requirements of Reference 2.5.
8.2 Regulatory Requirements
10 CFR 19.12 states the training requirement for radiation workers and shall be adhered to for this project. 29 CFR 1910.120 states that all employees working on site (such as but not limited to equipment operators, general laborers, and others) who are exposed to hazardous substances, health hazards, or safety hazards, their supervisors, and management responsible for the site shall receive training that meets the requirements of 29 CFR 1910.120 e, (2), 29 CFR 1910.120 e(4), 29 CFR 1910.120 e (3(I)) and 29 CFR 1910.120 e(4).
8.3 Implementation
8.3.1 Topics
In order to implement the requirements of 10 CFR 19.12 and 29 CFR 1910.120, site workers shall be instructed in the following topics:
8.3.1.1 Fundamentals of Health Protection
1) The radiological and toxic hazards of exposure to radioactive materials.
2) How radioactive materials enter the body (inhalation, ingestion, skin penetration).
3) exposures to radioactive materials should be kept ALARA.
8.3.1.2 Personal Hygiene at the Site
1) Wearing protective clothing.
2) Using respirators and breathing air systems correctly.
3) Eating, drinking, smoking, and chewing only in designated "clean" areas.
4) Using proper methods for decontamination.
8.3.1.3 Site Specific Control Systems
1) Standard operating procedures.
2) RWPs.
3) Security and access control to designated areas.
4) Hazards specific to the BOMARC Project.
8.3.1.4 Health Physics Protection Measurements
1) Measurement of airborne radioactive materials.
2) Bioassays to detect radioactive materials (urinalysis and/or in-vivo counting).
3) Surveys to detect contamination of personnel And equipment.
4) Personnel dosimetry and dose limits.
8.3.1.5 Radiation Protection Regulations
1) Employee rights in 10 CFR 19.
2) Radiation protection requirements in 10 CFR 20.
3) Prenatal Radiation Exposure Concerns (NRC Reg. Guide 8.13).
8.3.1.6 Hazardous Materials Protection
1) Hazardous Material Safety Data Sheets (MSDS).
2) Confined Space Entry Procedures, where applicable.
8.3.1.7 Industrial Safety and Health
1) CN-SF-020, "Minimum Industrial Safety Standards for Chem-Nuclear Systems."
2) Site Safety and Health Plan.
8.3.1.8 Emergency Procedures
1) Personnel injury
2) Fire
3) Site evacuation
4) Emergency procedures in the Site Safety and Health Plan
8.3.2 Radiation Control Technicians
Radiation Control Technicians shall be trained per the requirements of Reference 2.4.
8.4 Documentation
All workers shall be tested on their comprehension of the training instruction and shall sign a statement acknowledging that they have received the training and shall comply with the radiation protection rules and requirements before being allowed to enter a radiation or airborne area. All workers shall sign a statement indicating that they have reviewed their incorrect answers to the test and understand why they are incorrect. These tests and statements shall be maintained in the individual's personnel files.
9.0 CALIBRATION OF EQUIPMENT
Radiological field survey equipment and laboratory analysis equipment shall be calibrated using standards traceable to National Institute of Standards and Technology (NIST). Calibrations shall be performed by qualified personnel on a semi-annual basis, or when repairs or performance indicate a need, and as designated by the CHP. Certain types of equipment may be calibrated in the field depending upon the operating characteristics of the equipment.
Field response checks will be made of equipment prior to use. Included in these checks are limited functional checks to ensure proper operation of the electronics. These requirements shall be implemented through Reference 2.8.
10.0 RADIOLOGICAL CONTROLS
Radiological Controls shall be implemented per the requirements of Reference 2.7
10.1 Potential Radiological Hazards
The following text describes potential radiological hazards associated with the performance of project activities. Exposure pathways that must be addressed include the following:
10.1.1 External Exposure To Gamma, Beta And Alpha Radiation
Alpha particles are readily stopped by the outer dead layer of skin and are not normally considered an external exposure hazard. Beta particles are readily stopped by thin layers of material, and protective clothing is useful for reducing exposure to extremely low levels. Beta radiation, although more penetrating than alpha radiation, will be stopped by protective clothing or within the outer dead skin layers. Beta radiation protection for eyes and sensitive areas should be used to minimize internalization. Gamma radiation will penetrate significant thickness' of material, and protective clothing is of insignificant value for the reduction of exposure. Methods of reducing exposure to gamma radiation include minimizing the time spent in close proximity to the material, maintaining sufficient distance from any significant sources, and introducing shielding materials between sources and personnel. For the work activities to be performed and the levels of material present at the project site, the potential hazard associated with external exposures to radiation are minimal.
10.1.2 Inhalation of airborne radionuclides
Interior or exterior surfaces of equipment and structures may be contaminated with removable, dispersible contamination. Soils may be contaminated with dispersible contamination. Appropriate engineering controls such as containments, ventilation systems, administrative controls, and respiratory protective equipment will be used as necessary during specific activities to reduce the potential inhalation or ingestion of these contaminants by workers. Selection of appropriate protective measures will be based upon results of surveys and sampling prior to and during work activities.
10.1.3 Ingestion of radioactive contaminants
Airborne or surface contamination may be transferred to the mouth of an individual through breathing or direct physical contact. Methods of minimizing internal exposures via ingestion include conducting contamination measurements when leaving potentially contaminated areas, maintaining good work practices and good hygiene during the project, prohibiting acts with an increased likelihood of contamination ingestion, and wearing appropriate personal protective equipment.
Specific radiological hazards for are shown in Table A-10.1. All radiological hazards may be present during any on-site activity in the Restricted Areas or CRZs.
10.2 Radiological Monitoring and Sampling
The following paragraphs describe the surveys and monitoring to be conducted by CNS during the course of the project.
10.2.1 Gamma Dose Rate Surveys
Gamma dose rate surveys of areas, equipment, materials, or drums shall be performed in accordance with approved procedures and RWPs or as directed by the CHP. CNS will perform occupational gamma dose rate surveys at the BOMARC site. Baseline surveys shall be performed to determine average exposure rates in the work area and at the perimeter of the work area. Exposure rate surveys will be performed using appropriate survey meters.
Weekly thereafter, radiation exposure rate surveys will be conducted at the perimeter and in the work areas to assess the levels of radiation to which workers are exposed. The administration and break areas and surrounding areas will be included. Results of surveys shall be maintained on file by the CHP.
10.2.2 Contamination Surveys
The external surfaces of equipment, tools and other items will be surveyed for contamination as directed by the CHP. Dry smear samples of removable contamination will be taken of equipment, tools and other items prior to their removal from the controlled area. The dry smear samples will be counted for alpha, beta, and gamma radioactivity using appropriate radiation detectors.
Contamination surveys will be performed daily at access control points to assess the adequacy of contamination control. Also daily contamination surveys will be conducted in controlled work areas.
Smear surveys will be conducted on materials and surfaces along with the baseline gamma survey to identify areas of higher levels of removable contamination.
Results of surveys shall be maintained on file by the CHP.
10.2.3 Personnel Contamination Monitoring
10.2.3.1 Access Control Point
All personnel leaving the CAA at the BOMARC project shall be monitored for contamination with an appropriate instrument. Contaminated personnel shall be decontaminated prior to departing from the site. A personnel contamination log will be maintained at the site by the CHP.
When personnel exit a controlled area, they will perform the following:
Doff anti-contamination clothing in accordance with the SSHP. Place the clothing in the disposable clothing containers.
Perform an exit survey using the step-off pad as necessary.
10.2.3.2 Exit the area.
Monitoring instruments must be able to reliably detect low level contamination on personnel. Trained personnel designated by the CHP may monitor themselves.
10.2.3.3 Periodic Surveys
Periodic surveys of personnel working in areas of higher contamination shall be conducted as directed by the CHP. Particular attention shall be paid to items of PPE that frequently come in contact with contaminated items. PPE exhibiting high contamination levels as determined by the CHP should be changed to reduce cross contamination.
10.2.4 Radiological Instrumentation
CNS shall maintain instrumentation sufficient to perform direct radiation, contamination, and airborne surveys. The instruments shall be calibrated at least semiannually and maintained in accordance with Reference 2.8.
10.3 Radiological Airborne Contaminant Monitoring
10.3.1 Personnel Monitoring
Personnel samples will be as necessary or as directed by the CHP. Employees selected for monitoring will include those with the highest risk of exposure to radiological contaminants.
10.3.2 Ambient Air Monitoring
Samples for airborne particulate radioactivity will be obtained from the Radiation Control Area (RCA) whenever radiological operations are being performed. The samples will be collected on a glass fiber type filter paper, using a high volume air sampler, low volume air samplers or lapel air samplers. These samples will be used to determine/evaluate the need for respiratory protection. Additionally, samples for airborne particulate radioactivity will be collected at the boundary of the restricted area. These samples will be collected on a glass fiber type filter paper, using a continuous low volume air sampler. These samples will be used to verify compliance with release criteria for airborne radionuclides to unrestricted areas as specified in 10 CFR 20.
Perimeter radiological airborne contaminant monitoring systems, such as continuous air monitors (CAM), will be set up on locations due north, south, east and west of the area being worked. An additional CAM may be placed in the down wind direction if deemed necessary by the CHP. Grab samples will be used,, as needed, to determine airborne radiological conditions at specific areas.
10.4 Decontamination
Decontamination of personnel and equipment will be performed to reduce worker risks and prevent the spread of contamination outside of the radiological controlled area.
10.4.1 Personnel decontamination
10.4.1.1 Personnel decontamination may include washing affected areas with warm soapy water and containment of wash and rinse water for analysis and treatment in accordance with Reference 2.7. The PHP shall be notified of personnel contamination events.
10.4.1.2 Personnel decontamination events will be reported and documented in accordance with Reference 2.7 and 2.9.
10.4.2 Equipment decontamination
10.4.2.1 Equipment decontamination may include dry wipes of affected areas up, high pressure washing, or vacuuming of affected areas. If liquids are used during equip-ment decontamination a containment to collect all liquids will be used. All liquids used for decontamination will be collected, analyzed and treated for disposal.
10.4.2.2 Equipment decontamination events will be documented in accordance with Reference 2.7.
11.0 WASTE PACKAGING
All "secondary" radioactive waste material will be packaged in B-25 type metal boxes or 55-gallon drums for future disposition. Secondary waste may be considered used materials associated with the excavation process such as gloves, cleaning wipes, used personnel protective equipment, and miscellaneous small items. These containers will be sealed and surveyed prior to shipment. Waste packaging and shipping will be conducted in accordance with USDOT regulations.
12. 0 RECORDS AND REPORTS
12.1 Records and reports required in procedures and work instructions will be maintained as specified in Reference 2.10. Copies of records and reports will be available upon request.
12.2 The results of sampling, analyses, surveys, monitoring, and equipment calibrations, as well as reports of audits and inspections, shall have a lifetime retention period in accordance with Reference 2.10.
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