Reports to MHSA

IV.G-5 Inspection and Sampling Policy for Radiation at Underground Mines Underground metal and nonmetal mines shall be inspected and sampled for radiation hazards as follows:

1. Where radon daughters exceed 0.1 WL, sample quarterly at full-time producing (FTP) underground mines and whenever a regular inspection is conducted at intermittent (INT) underground mines.

2. Sample for radon daughters annually at all other underground metal mines and at other underground nonmetal and stone mines where radon daughters have occurred in the past.

3. Sample remaining underground nonmetal and stone mines for radon daughters every three years.

4. Monitor underground mines for other forms of radiation as warranted.

57.5039 Maximum Permissible Concentration (Radon Daughters) Except as provided by standard 57.5005, persons shall not be exposed to air containing concentrations of radon daughters exceeding 1.0 WL in active workings. In enforcing this standard, the error factor for radon daughter sampling of 20% should be taken into consideration. This means that citations are to be issued when the measured radon daughter concentrations are in excess of 1.20 WL.

Also, this standard applies only to active work areas when workers are present or scheduled during the shift and, if workers are not present or scheduled, when evidence is available that other personnel normally enter the work area during the shift.

57.5040 Exposure Records (Radon Daughters) "Significant and Substantial" Violation Inadequate recordkeeping may result in excessive exposures to radiation going undetected and unremedied. Where the violation has actually or potentially contributed to this hazard, the citation will be designated "significant and substantial." Generally, such findings will be appropriate where:

1. The operator fails to keep personal exposure records, or

2. The operator has falsified or altered records or continuously understated the accumulated exposures.

Where such failures are the result of the operator's disregard for the recordkeeping requirements, such violation may also be considered unwarrantable.

In cases where no hazard results, a violation shall be cited as a technical violation without "significant and substantial" findings.

Respirator Credit >

Where respiratory protection is used pursuant to 57.5044 and in compliance with 57.5005, that is, entry into hazardous areas for reasonable periods of time to establish controls or occasional entry for investigative or maintenance purposes, MSHA will allow respirator credit on mine employees' radon daughter exposure records. Respirators used for protection against radon daughters must be capable of removing 90 percent of the radon daughters from the respired air.

Credit will not be allowed for the wearing of respirators while performing any type of production work, regardless of the radiation levels.

57.5045 Posting of Inactive Workings
Inactive workings in which radon daughter concentrations are above 1.0 WL shall be posted against unauthorized entry and designated by signs indicating them as areas in which approved respirators shall be worn. This standard applies to inactive workings (e.g., worked-out sections only).

Active workings are subject to 57.5039. See 57.2 for the definition of "active workings" and 57.5040(a)(1) for examples of areas considered "active workings." Standards 57.5044 and 57.5046 for respiratory protection apply to both active and inactive workings.



57.5046 Protection Against Radon Gas< i>

Where radon daughter concentrations exceed 10.0 WL, respirator protection against radon gas shall be provided (in addition to protection against radon daughters).

< i>Because of the rare special circumstances of working in atmospheres that contain radon daughters above 10.0 working levels, there are no respirators or gas masks specifically approved by NIOSH for removal of radon gas. A self-contained breathing apparatus or a continuous flow airline (pure-air) respirator would satisfy the requirements of this standard.

57.5047 Gamma Radiation Exposure Records "Significant and Substantial" Violation

Inadequate gamma radiation exposure records may result in undetected and unremedied excessive exposures (see 57.5047(d)). Where the violation of 57.5047 has actually or potentially contributed to this hazard, the resulting citations will be designated "significant and substantial." Generally, such findings will be appropriate where:

1. The operator fails to keep personal exposure records, or
2. The operator has falsified or altered records or continuously understated the accumulated exposures.

Where such failures are the result of the operator's disregard for the recordkeeping requirements, such violation may be considered unwarrantable.
In cases where no hazard results, a violation shall be cited as a technical violation without "significant and substantial" findings.



http://www.msha.gov/REGS/COMPLIAN/PPM/PDFVersion/PPM%20Vol%20IV.pdf


56/57.5002 Dust, Gas, Mist and Fume Surveys by Mine Operators
These standards require mine operators to conduct dust, gas, mist and fume surveys as frequently as necessary to determine the adequacy of control measures. The purpose is to help assure that the miners are not exposed to harmful concentrations of airborne contaminants.

These standards apply to those air contaminants covered under 30 C.F.R. §§ 56/57.5001(a) and (b) and do not apply to standards for radon, diesel particulate matter, or noise since those standards contain specific monitoring requirements. Mine operators must demonstrate compliance with 56/57.5002 rather than relying on enforcement interventions. MSHA emphasizes that mine operators:


Commonwealth of Virginia Uranium Study: Final Report:  http://www.dmme.virginia.gov/Uranium/pdf/Exhibit_E_Air_Qual_Mon_Report_Final.pdf

Search Government Publications:  National Emission Standards for Radon Emissions From Underground Uranium Mines:  http://www.gpo.gov/fdsys/search/searchresults.action;jsessionid=Kkn4STZhv21mmN7mkfCq0VVq3JnzpCGy5D2MVtyN0GhGjRLH1h2k!774774635!974093854?st=National+Emission+Standards+for+Radon+Emissions+From+Underground+Uranium+Mines