Dr. Channell received a Ph.D. in Environmental Engineering, Stanford University; a M.S. in Environmental Engineering, University of Florida; and a B.S. in Civil Engineering, University of Washington.

RADIOLOGICAL SURVEYS TO INDICATE HAZARDOUS WASTE RELEASES: In EEG's previous submissions, EEG stated its views on the applicability of using radiological measurements to detect hazardous releases (co-detection) and that an effective system of detecting releases of radioactive material should be required in the final Permit. More detailed information should be provided in the final Permit on release notification requirements, cleanup criteria, and timeliness of laboratory analyses to judge whether this procedure will be an effective control. However, EEG understands that NMED is not relying on the WIPP radiological measurement system for measurement and control of hazardous releases.

UNCLEAR REQUIREMENTS AND CONSEQUENCES: Compliance criteria, reporting requirements for non-compliance, and consequences of non-compliance are not directly addressed in the draft Permit. Neither are the consequences of exceeding the limits on storage times and numbers of TRUPACT-IIs in the parking area.

VOC CONCENTRATION LIMIT ISSUES: EEG has performed separate calculations of the lifetime risks of NMED's proposed Room-Based Limits and Concentrations of Concern. EEG modified the source term in several cases. EEG agrees with NMED's calculation for the total lifetime excess cancer risk from the sum of all carcinogenic VOCs for a non-waste worker as well as for a resident at the site boundary. EEG agrees that NMED's proposed room-based limits meet the criteria for the site boundary resident. EEG also agrees that the surface worker is adequately protected.

Separate calculations by EEG using NMED's Concentrations of Concern lead to lifetime risks from each VOC for the boundary resident and for the surface worker that--though over the lifetime limits--are, EEG believes, adequately protective of public health. The levels are unlikely to be exceeded by more than one or two VOCs at any time, and the lifetime risk levels are based on continuous exposure (35 years for the resident and 10 years for the surface worker). Also, if any VOCs exceed the Concentrations of Concern, the active disposal room or Panel is required to be sealed so overexposure would be corrected quickly.

EEG agrees with the Lower Explosive Limit Criteria used by NMED for closed disposal rooms in the room-based limits for chlorobenzene, toluene, and 1, 1, 1-trichloroethane.

EEG agrees that room-based limits should be imposed so that Immediately Dangerous to Life and Health (IDLH) concentrations would not be exceeded in open rooms adjacent to a closed room that experiences a roof-fall; however, there are problems in evaluating whether or not appropriate limits have been chosen. There is no mention of how the assumption was determined that 5% of headspace gas VOCs in a closed room would be expelled in a roof fall. It could be more or less than 5%. The short-term transient pressure pulses and releases in a roof-fall are difficult to model, and it is hard to justify that some assumptions are more valid than others. However, DOE and NMED calculations are reasonable for VOC releases. The calculations were made under the assumption that the closed room contained magnesium oxide (MgO) backfill, which left only 1.5 feet of open space at the top of the room. If the MgO backfill were eliminated, the open space would be 3.0 feet.


Other assumptions that the DOE made when doing the air risk assessment are conservative and would lead to an overestimation of gas generation. For instance, the surface worker calculation was based on cumulative worker exposure from the maximum room-based limits.

The same kind of lifetime risk calculations could be done for solid RCRA regulated materials if the data were available, but data on these materials are not available. There are some data in the Baseline Inventory Reports (BIR) that allude to these materials, but there is no information on them in the Permit Application. At the generator sites, recordkeeping was not related to RCRA solid materials but to radionuclides. Neither the Application nor the Permit discusses non-VOC hazardous releases in a roof-fall.

Drum VOCs vary. Headspace gas concentrations and DOE measurements do not capture all the VOCs in a drum.

EXHAUST AIR: EEG has historic concern about emissions from the underground through the exhaust system. There should be a reliable fixed air sampling device above ground to record emissions from WIPP. There should be Continuous Air Monitors (CAMs) that are reliable and well located to detect releases underground. In the case of a detected release, exhaust air can be switched to the filtration system. There is a sampling device in the exhaust shaft, but excessive moisture in the shaft air means that many of the samples may not be representative. An underground tracer study was done a year ago to determine whether or not the CAMs were receiving representative samples in their present locations, but that test has not been completely reviewed yet.

The DOE assumes that the effective gas generation rate (of VOCs and other gases) is 0.5 moles/drum/year, and EEG believes that assumption is conservative. During a roof- fall in an open room, gas may travel into fractures in the formation. A roof-fall in a closed room may cause the room to remain slightly pressurized because the gas cannot escape. In either case, gases could be expelled into the Salado and possibly into the interbeds. Migration of VOCs is easier if there is no MgO backfill. During routine operations gases diffuse through the container vents into an open room and are carried by ventilation air up the exhaust shaft. At the boundary of the site the routine VOC releases are of more concern than releases from a roof-fall.

There is not much variation of temperature inside a TRUPACT-II, no matter what the season or temperature outside the container.

At INEEL headspace gas sampling is completely automated.

The DOE believes 5% of gases would be expelled during a roof-fall, but the amount coming out depends on assumptions. Without experimenting and reproducing the roof-fall, one cannot have confidence in the numbers. The DOE is not planning on doing any such experiments. A roof-fall scenario for an open room is detailed in the draft Permit. The consequences are less severe than for a closed room.

The primary concern with release-detection monitors is whether they can accurately predict when there is enough of a release to switch to filtration of the exhaust air. It is not clear that samples are representative at the locations the DOE has picked for the underground monitors. EEG still recommends multiple CAMS, but further study is needed to determine the proper location of those monitors. The main concern is that without multiple monitors, one might not always know when there is a release. Releases could occur when workers are not in a room. Also, many production or laboratory facilities dealing with transuranic material have multiple CAMs in a single building or large room because there is a danger of localized releases.

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