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Appendix T- Detailed Description of Alternative 3: DOEIRI^2001-1 t
Entombment with Internal Waste Disposal Rev. al nrafi n
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I High radiation arcas and very high radiation areas would be encountered and would primarily be
2 a concern during equipment removal. For example, approximately 25% of the cells have
3 equipment and materials that have high radiation levels that exceed 1,000 mremJhr. The
4 maximum gamma dose rate in cell 30 was 190,000 mrem/hr (BHI 2001a). Also, the most
5 significant radiological hazard anticipated during operational activities would be the generation
6 of airborne contamination. Mitigation of airborne contamination would be accomplished with
7 local exhaust ventilation of the decontamination equipment, personal protective equipment,
8 existing facility exhaust system, and administrative controls and physical controls.
9 Decontamination or fixing of loose or stnearable contamination would be performed prior to any
10 removal/demolition activities. Radiological limits for worker protection are provided in 10 Code
I1 of Federal Regulations (CFR) 835.
12
13 Nonroutine activities would require special procedures and equipment so that the risk of
14 exposure is properly mitigated. Safety criteria would be determined on a case-by-case basis;
15 however, criteria would require that exposures be as low as reasonably achievable (ALARA).
16
17 Administrative controls include radiation work permits, exposure limits, and escort requirements.
18 Physical controls include barriers, postings, and personnel surveys. In accordance with site
19 procedures, administrative and physical controls applicable to this project would be defined in
e,,20 job-specific work plans and procedures. Compliance with the job-specific work practices and
>_I procedures would ensure that personnel exposures do not exceed allowable limits.
22
23 Installing a perimeter fence and implementing a site-entry procedure would control access to the
24 work site. The procedure would require either training or escorts for site visitors. Additionally,
25 operating methods that depend primarily on equipment would be used, and the number of
26 operating personnel would be minimized to the extent practicable.
27
28 F1.1.1.2 Control Envtronmental Hazards. The potential dispersion/migration of dangerous
29 and)or radioactive waste would be an inherent risk of Alternative 3. Wind is the principal cause
30 of dispersion, and water is the main transport mechanism for migration. Dangerous/radioactive
31 contaminants could also migrate through the inadvertent contamination of vehicles and personnel
32 leaving the project site. Radiological limits for exposure to the public are provided by
33 DOE Order 5400.5, Radiation Protection ofthe Public and the Environment.
34
35 Implementing a combination of procedural and physical controls would mitigate wind dispersion
36 of contaminants. Procedural controls typically consist of wind-speed restrictions on work
37 activities. Physical controls include spray fixatives ( i.e., water sprays and chemical coagulants).
38 minimizing the size of the work area, pressurized application of concrete slurries through a hose
39 and nozzle (guniting), clean fill, and/or containerization. Radiation air monitoring would be
40 performed on the work site perimeter to confirm the effectiveness of airborne contamination
41 control.
42
1'43 The potential for water migration would also be mitigated by implementing a combination of
44 procedural and physical controls. Procedural controls would consist of work restrictions during
45 precipitation events if the potential for contaminant migration exists. Physical controls would
Final Feasibility Studyfor the Canyon Disparftion initiative (221•U FacRity)
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