TESTIMONY OF DR. JAMES K. CHANNELL;
March 2, 1999.
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.
HIGHLIGHTS OF CROSS-EXAMINATION OF DR. JAMES K.
CHANNELL:
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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