ML20249C052
| ML20249C052 | |
| Person / Time | |
|---|---|
| Site: | 07003085 |
| Issue date: | 08/31/1997 |
| From: | External (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20249C047 | List: |
| References | |
| NUDOCS 9806250230 | |
| Download: ML20249C052 (21) | |
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REVIEW OF DRAFT ENVIRONMENTAL IMPACT STATEMENT I
DECOMMISSIONING OF THE BABCOCK & WILCOX'S SHALLOW LAND DISPOSAL AREA IN PARKS TOWNSHIP, PENNSYLVANIA U.S. NUCLEAR REGULATORY COMMISSION DOCKET NO. 70-3085 LICENSE NO. SNM-2001 August 1997 PADEP Contract No.: Me 93936 Work Assignment No.: 20-019 Submitted to:
Commonwealth of Pennsylvania Department of Environmental Protection Submitted by:
Ogden Environmental and Energy Services Co., Inc.
1777 Sentry Parkway West Abington Hall, Suite 300 Blue Bell, Pennsylvania 19422-2223 Ogden Project No. 47014-0009 December 9,1997 1
9906250230 990615 C
^ ADOCK 07003085 PDR PDR
~~.e I.
GENERAL COMMENT
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-A. SURFACE SOIL CONT ALNIW AMERICIUM & PLUTONIUM IN THE VICINITY l
OF TRENCH 10 I
Regarding Trench 10, NRt.ma ORNL agreed at the 12/18/96 meeting to include a discussion of
' Trench 10 in the EIS, including discussions of the requirement to remove soils containing Pu > 25 pCi/g and Am > 30 pCi/g and more quantitative analysis. The discussion of Am and Pu was l
extended in the Working DEIS and expanded even more in the DEIS (August,1997). However, L
there are still some misleading statements and omissions in the DEIS.
l For instance, NRC & ORNL agreed at the December 1996 meeting that the decision of which soils should be removed should be based on total plutonium and not just the plutonium isotopes
. that were measured in 1995 with beta spectroscopy. This can be done by using total plutonium to americium ratios determined by alpha spectroscopy from previous data (as discussed on page 1 of
- the PADEP comment document on the Preliminary DEIS.) Discussion of total Pu was not incorporated into the Working DEIS or the DEIS (August,1997).
The short discussions found in the Working DEIS on pages 3-21 and 3-35 stating that americium and plutonium were detected in sur6cial soils near Trench 10 were expanded in the DEIS (August 1997). For instance, on page 3-22 it is stated: "..B&W has committed to remediating any Am or Pu contamination which is above NRC unrestricted release criteria... During this remediation, additional sampling will be performed to determine the extent of this contamination and any area exceeding NRC release criteria will be remediated even ifit extends to depth in the trench," and on page 3-52, it is stated: "Therefore, any Am and Pu contamination above NRC's release criteria
_will be removed, including material which is at depth."
These statements represent significant progress, because they clearly state that remediation is planned and they acknowledge that Am and Pu is present at depth and in the trench. However, the discussion of total Pu (see above) is missing, and the reference to "any area" may indicate that B&W is intending to average samples within areas. PADEP notes that unrestricted use criteria (NRC.1992, Current Guidelines on Acceptable Levels of Contamination in Soil and Groundwater on Property to be Released for Unrestricted Use) do not apply to average soil concentrations.
According to the NRC citation, marimum soil concentrations must not exceed the criteria. Thus, all soils exceeding the criteria must be remediated.
t As in the Working DEIS, the DEIS (August 1997) states that the source of the Am and Pu is
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likely to be equipment from the Miity that was parked in this area and not the wastes disposed in Trench 10. On page 3-22 and 3-Yi, the contamination is still referred to as surface contamination (e.g. " Trench 10 has low potential for impacts because the storage of equipment on the surface was the apparent source of the Am and Pu contamination.") As PADEP noted in comments'to both the Preliminary DEIS and the Working DEIS, the available data and information do not 2
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4 identify the source of the Am and Pu. Six out of seven of the grid locations having the highest average Am-241 concentrations are very near the trench. Little contamination was found along the road, where one would expect facility equipment to be parked. Also, no data are available regarding the levels of Am-241 at depth in the trench area, except the 1993 data showing contamination at depth within the trench. A copy of Table 5-8 of the Site Characterization Report (SRC) is included which shows evidence of Am at depth. As shown, in three of the five j
samples taken from Trench 10 having data at the surface and at depth, samples at depth were
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higher in Am. The highest detected Am was in a sample taken from 4-6 feet. Thus,it is i
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I possible that Trench 10 is the source of the americium and plutonium contamination in the area.
PADEP is concerned that the DEIS (August 1997) has restated ARCO /B&W's statements and has not based its conclusions on the data.
In response to the statement in the Working DEIS (page 3-21) that Am-241 in trench solids was less than 1 pCi/g, PADEP noted that no americium was detected in trench solids with the following respective detection limits,2.3 pCi/g,16.2 pCi/g, and 1.6 pCi/g PADEP requested that the statement be modified to state that americium was not detected with detection limits ranging j
from 2-16 pCi/g. The DEIS (August 1997) adds the statement about the detection limits but does not remove the statement that Am-241 in trench solids was less than 1 pCi/g. The I pCi/g statement is simply not true. The truth is that americium was not detected with detection limits ranging from 2-16 pCi/g.
No additional references to Am and Pu were made in the DEIS (August 1997). In conclusion, PADEP requests that NRC: (1) include a discussion of remedial decision making based on measured or estimated total Pu, not just selected Pu isotopes,(2) replace all references to surface contamination with a discussion of surface and subsurface contamination,(3) acknowledge that unrestricted release criteria apply to individual samples, not area means, and (4) remove reference to 1 pCi/g in the discussion of trench solids analyses.
B. PROPOSED HYBRID REMEDIAL OPTION l
l The DEIS (August 1997) still does not address PADEP's suggested hybrid remedial option. This option would specify that the wastes from Trenches I and 10 would be removed and SIP would apply to the remainder of the SLDA. Trench 10's isolation from the remainder of the trenches and its presence at the coal outcrop with direct communication into the deep mine convince us l
that it should not be addressed in the same manner as the other trenches and removal seems an attractive option. There are several reasons why removal of the contents of Trench 1 is a logical proposal. NRC states on page 3-45 of the Working DEIS that 84% of the uranium loss rate for the entire site is associated with Trench 1. Other data also suggest that it would be logical to l
focus a limited removal action on Trench 1. As shown in Table 1, several data sets demonstrate that the uranium concentration in leachate from Trench 1 is much higher than in other trenches.
Also, there are more soil samples around trench I that exceed both 30 pCi/g and 100 pCi/g than around other trenches NRC also estimates that the total content of radioactivity residing in Trench 1 is higher than the amount in other trenches.
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TABLE 1 Trench #
Total U Total U Total U Total U-
- of Soil Estimated Activity in Activity (1995) 335 Samples Total U Solids (1995)in ICP-MS Activity by Exceeding content (pCi/g)'
Leachate (ug/L)2 2" Gamma 100 pCi/g (Ci)'
(pCi/L)2 Log Total U (pCi/g)'
Activity' 1
2111 5074 1433 22 9
.58 2
1104 512 55 23 6
.43 4
1049 1195 43 25 2
.12 5
8803 591 49 28 4
.18 6
46 146 12 74 1
.27 7
2971 1063 87 27 2
.27 8
191 9
<1 0
0 9
700 182 9
0
.15 10 144 81 4
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0 1 Appendix J 1995 Field Work Report 2 Exhibit 2.2.1,1995 Field Work Report 3 Table 7, Appendix A,1995 Field Work Report 4 Figutes 5-11 thvough 5-24,1993 Site Characteri:ation Report 5 Table 3.2.2, Working Draft Environmental Impact Statement The exception to this trend are results from analyses of solids from TWSP leachate samples, shown in Table 1. Although the specific activity in solids from Trench 1 are high, the average results from Trench 5 are much higher. However, ARCO /B&W explains in the 1995 Field Work l
Report that the particles filtered from the teachate samples are fine particles with a high capacity for radionuclides adsorption. Uranium specific activity on these solids would not be expected to correlate with total radioactivity in the trenches.
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Thus, it is reasonable to focus a removal action on Trench 1. The most mobile radioactivity l
would be removed. However, at the December 1996 meeting, NRC reported that the EIS j
process would need to be re-scoped to formally consider any new option. Since this option was I
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process would need to be re-scoped to formally consider any new option. Since this option was not specifically listed in the EIS Scope of Work, it cannot be simply added into the document, accordi'ng to NRC.
PADEP notes that the modified SIP (MSIP) option that is the NRC staff preliminarily recommended remedial option was also not specifically listed in the EIS Scope of Work. PADEP would like NRC to explain how this major, new option can be presented in the Working DEIS with minimal backup as the NRC-recommended option. Isn't it true that the EIS must be re-scoped with public notice and comment before making such a major departure from the options that were presented in the formal Scope of Work?
PADEP also requests that NRC consider redefming the modified SIP IMSIP) option to be a hybrid option, similar to PADEP's previous proposal. The Hybrid Modified SIP (HMSIP) remediation would require disposal offsite of the waste in Trenches 1 and 10 and specify the NRC's preliminarily proposed MSIP option for the remainder of the site. The estimated cost of HMSIP would be much less than the costs of SIP or DOS, as proposed by ARCO /B&W.
In conclusion, PADEP requests that NRC seriously consider its hybrid remedial option that would result in Disposal Off Site of some waste and Stabilization in Place or Modified Stabilization in Place for the remaining waste. If this alternative is not formally included in the DEIS, PADEP requests a formal explanation of why this alternative was not considered.
Please understand that PADEP is not endorsing this hybrid remedial option but only requesting that it be evaluated along with the other options.
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II. SPECIFIC COMMENTS FROM PRELIMINARY AND WORKING DEIS SUMM'ARY The summary section is a new section. PADEP is pleased that the first paragraph refers to the i
Am and Pu detections and that the second paragraph from the bottom of page xx mentions the Aen and Pu issue. However, the Geology and Soils Section continues to conclude that the Am and Pu is a surface soil issue only and that its source was equipment storage on the surface. As noted above in these comments, site data indicate that Am and Pu are present in subsurface loca9ons within Trench 10, and the conclusion that the source of Am and Pu is from equipment storage is based only on ARCO /B&W statements and not on site data.
Accordingly, PADEP requests NRC to remove statements about the source of Am and Pu and to sts.te that the source is unknown or that the source is believed by the licensee to be equipment storage. Also, please remove references to Am and Pu as a surface issue and add that the licensee has committed to cleaning up surface andsubsurface contamination to levels below the unrestricted use criteria.
I The Human Health Section states that the groundwater pathway is not a credible pathway.
PADEP notes that this would be a credible pathway if fracture flow were occurring or might occur in the future. ARCO /B&W stated in earlier documents that fracture flow might occur, but then concluded based on the 1995 field work that it does not and would not occur. NRC apparently also believes that fracture flow is not relevant. However, PADEP has repeatedly requested that ARCO /B&W and NRC simply provide the basis for this conclusion for PADEP's evaluation. This issue is a critical one for performing a risk assessment for the site. PADEP is entitled to see an analysis of current site data that supports the dismissal of fracture flow as a relevant site issue.
Thus, PADEP requests that NRC formally evaluate the issue of fracture flow in the DEIS (August 1997).
The Human Health Section also states that the public exposure limit is 100 mrem / year. PADEP believes that this is a misleading statement. On May 21,1997 NRC approved maximum permissable radiation levels for license termination. The permissable level for unrestricted release is "as far below 25 millirems per year as is reasonably achievable." For restricted release, the permissable level is "as low as is reasonably achievable," and legally enforceable institutional controls must " ensure that the dose does not exceed 25 millirems per year." The DEIS refers to 100 mrem / year. This limit refers to the maximum dose level that cannot be exceeded "if the institutional controls were no longer in effect."
PADEP requests NRC to clarify current, applicable public exposure limits and state that the applicable goalis 25 mrem / year.
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l The Costs and Benefits Section states that the cost of the DOS option is high. PADEP requests l
that NR.C address the lower costs of a selective DOS option in which waste was removed from one or more trenches and SIP was applied to other trenches.
The conclusion makes a misleading statement that "no off-site dose is expected." While it may be true that off-site doses are expected to be very low, they are not zero, especially if fracture flow can occur. PADEP requests that this statement to be modified accordingly.
SECTION 1 INTRODUCTION t
The comment was previously made that the Preliminary DEIS downplayed the significance of Trench 3. NRC responded in the Working DEIS on page 3-36 by providing a discussion of the function of Trench 3. It is stated that liquids from Trenches 4 and 5 were drained into Trench 3 and then tested. If contaminated, they were drained into Trench 2. If uncontaminated, they were allowed to remain in Trench 3. This information did cause PADEP's concern about Trench 3 to be reduced.
However, PADEP requested that citations be provided for the statements about testing the leachate and removing it to Trench 2 when contaminated. The requested information was not provided in the DEIS (August 1997).
In addition, the Working DEIS commented on the very high gross alpha measurement for the leachate sample from Trench 3 (29,500 pCi/L). This high reading was characterized as being "of highly questionable validity" on the basis that "the actual gross alpha level was about 5,100 pCi/L." Consequently, NRC did not include the 29,500 pCi/L value when characterizing the source. PADEP was very interested in NRC's conclusion, based on the " actual gross alpha level." PADEP requested the source of the alternate, lower gross alpha reading so that it could be reviewed. The requested information was not provided in the DEIS (August 1997).
In conclusion, PADEP requests that NRC provide the basis for its conclusions about Trench 3 leachate testing and its rejection of the 29,500 pCi/L trench leachate gross alpha reading. PADEP cannot evaluate NRC's position on these issues without reviewing the l
information upon which its conclusions are based.
SECTION 1.4 SCOPE OF THE EIS l
In this section, it is stated that "all reasonable alternatives to the proposed action are identified I
during scoping." This is not tme, because the NRC staff's MSIP option was not identified during
a
proposed action."
SECTION 2.2.9 SURVEILLANCE AND MAINTENANCE; STEADY STATE CONDITIONS PADEP'S comment about this section in the Working DEIS was that the time period for surveillance and maintenance should be determined before selection of the remedial option. The DEIS (August 1997) has addressed PADEP's comment and stated that the licensee is responsible for monitoring and maintenance for 30 years. After that time,"..the site would be transferred to a more permanent entity, such as the federal or state government for indefinite control. To account for uncertainties associated with long-term maintenance and monitoring, an upper bound cost of $1.5 million is estimated..."
PADEP believes that the licensee should be responsible for surveillance and maintenance for a period of time longer than 30 years. In addition, PADEP is surprised that NRC is considering transferring long term maintenance and monitoring to the Commonwealth of Pennsylvania. The facility was licensed by the federal government, and the only logical
" permanent entity" to assume indefinite control is the federal government. Accordingly, PADEP requests that NRC remove the references to " state government"in Section 2.2.9 and elsewhere.
ARCO /B&W did not provide any estimates of the costs associated with long-term maintenance after 30 years. Clearly, such surveillance and maintenance will be required for a very long period of time. In the Preliminary DEIS, the NRC made an estimate of $1,000,000 for the present worth estimate for such maintenance for the SIP and SOS options. At that time, PADEP stated that this amount appeared to be insufficient for the long time periods during which maintenance will be required for these two options.
In the Working DEIS, NRC modified its estimated costs for this requirement downward to
$600,000 in 1997 dollars. NRC staff believe that this minimum amount is sufIicient to provide for continuous income at a one percent real rate of return to provide the monies required to perform long term maintenance. PADEP questioned if this amount was sufficient.
The DEIS (August 1997) has addressed PADEP's concerns and has increased the estimate to
$1.5 million in 1997 dollars.
The $1.5 million was selected to provide an annual average real return of about $15,000 to support long-term mordtoring and routine maintenance, and possibly some non-routine repair and/or maintenance costs. PADEP believes that this funding amount is small and will not even cover limited monitoring / maintenance activities as identified below:
Event
. Est. Cost AnnualInspection/ Report 32,500 8
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I-h Sampling / Analysis'
$13,000
. Routine Maintenance (mowing, fence repair, etc.)
$4,000 Total AnnualCosts
$19,500
- Assuming semiannual sampling of 10 wells at 2 depths for limited parameters (~$250/ sample) with labor costs of $2,700 (32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> / year x $85/ hour).
Even with this limited set of monitoring / maintenance activities, the " Fund" would be prematurely l
depleted on an annual basis. The routine monitoring and maintenance costs would be even higher
. if PADEP and NRC require more frequent monitoring of more wells and/or for more parameters.
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In addition, it is not unreasonable to expect that some major /more significant maintenance
- activities will be required for the on-site disposal alternatives. - The NRC's MSIP option is expected to require the most major /more significant maintenance activities given that no cover soil material would be added to the site and there would be no stabilization of the slopes to Dry
. Run. In Section 3.3.2.2., the NRC states that landslides or slope erosion could occur between the upper trenches and Dry Run during an extreme flood. Some erosion would also occur during normal flooding which in time could expose the trenches. In addition, surface erosion of the soils over the trenches would occur in the form of sheet erosion. gu!!y erosion, slope destabilization and wind erosion, with gully erosion and slope destabilization being the primary contributes.
This erosion would require more significant maintenance activities than could be supported by the identified " Fund". The cost for these activities and other reasonably expected maintenance activities should be included in the Long Term Surveillance and Maintenance Fund, la conclusion, PADEP requests that NRC consider requiring an increase in the fund and eatending the licensee's obligation for surveillance and monitoring to a period longer than 30 years. In addition, PADEP requests that NRC remove the references to " state government"in Section 2.2.9 and elsewhere.
SECTION 2.3.1 WASTE EXCAVATION PADEP's comment about this section in the Working DEIS was that the plan to use a backhoe to remove buried drums'does not mesh with ARCO /L&W's assertions elsewhere that the drums would likely be msted and decayed and not be intact. Also, PADEP questioned the requirements in the cost estimates that a backhoe and a front end loader would be required for the entire excavation period. No changes were made to this section in response to PADEP's comment.
i However, NRC did perform independent cost estimates of the DOS option in another section.
l Accordingly, PADEP requests that NRC make a statement in this section that a backhoe and a j
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Accordingly, PADEP requests that NRC make a statement in this section that a backhoe and a front end loader are ueither necessary nor appropriate for waste excavation and that use of a backhoe is not consistent with the previous statements that buried drums would not likely be intact.
SECTION 2.3.2 WASTE TREATMENT PADEP's comment about this scction in the Working DEIS was that significant costs were projected for waste sorting and thermal treatment of soils and sludges when these steps may not i
be required. NRC has performed an independent cost estimation of the DOS option and has similarly questioned the need for these features.
Accordingly, PADEP requests that NRC make a statement in this section that the licensee's proposed waste soning and treatment scheme is overly complex, unnecessary, and tends to
~i escalate the estimated costs for the DOS option beyond reasonable expectations.
SECTION 2.5 OTHER ALTERNATIVES CONSIDERED PADEP commented that a hybrid DOS / SIP option should be evaluated as well as a discussion of soils removal in the Trench 10 area. Neither of these issues was addressed in this section in the DEIS (August 1997).
As noted above, PADEP requests that NRC seriously consider the PADEP hybrid remedial option j
that would result in Disposal OfTSite of some waste and Stabilization in Place or Modified Stabilization in Place for the remaining waste. If this alternative is not formally included in the DEIS, PADEP requests a formal explanation of why this alternative was not considered. Please l
understand that PADEP is not endorsing thi: hybrid remedial option but only requesting
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that it be evalusted along with the other options.
SECTION 3.3.1.1 Hi>ROLOGY - GROUNDWATER-UPPER TRENCH AREA Section 3.3.1.1 identifies depressions in the soil, first shallow bedrock, and second shallow bedrock aquifers northeast of Trench I and south of Dry Run and suggests that one possible cause of this phenomenon may be vertical leakage out of these aquifers caused by vertical fractures. PADEP requested that the DEIS provide a detailed explanation of fracture flow, because ARCO /B&W has concluded that fracture flow does not occur.
The DEIS (August 1997) does not provide a specific discussion of the most recent hydrological data regarding the possibility that fracture flow could occur. However, the model employed by NRC staff takes into account the possibility that groundwater and contaminants could move along preferential flow paths to on-site users by assuming an unretarded migration rate in its bounding analysis. However, the results of this bounding analysis are totally dismissed by NRC as being impossible.
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PADEP thus requests that the DEIS summarize the most recent hydrological data and l
evaluate the probability that fracture flow could occur.
Groundwater Quality PADEP noted that the characterization of groundwater quality in the Preliminary DEIS and the Working DEIS was incorrect sd incomplete. This is still true in the DEIS (August 1997). Most of the errors are errors of omission. Tables 3.6-3.13 demonstrate that VOCs were detected in numerous wells that are not identified in the text of the DEIS (August 1997). Thus, the reader of the text will incorredy conclude that VOC detections were restricted to three piezometers and four monitoring wells. PADEP requests that the text be corrected to include discussion of the VOC detects in the following additional wells or piezometers:
PZ-06 MW-10 MW-12D MW-28 MW-17 In addition, the DEIS (August 1997) states that gross alpha readings were elevated above drinking water standards at only two locations: PZ-2 and PZ-6. This is not true, because gross alpha measurements were elevated at several other locations:
GROSS ALPHA MEASUREMENTS Most Recent Mean Federal Drinking Water Std.
MW-27 86 pCi/L 31 pCi/L 15 pCi/L MW-20 17 9
15 MW-23 18 15 MW-30 16 15 i
GROSS BETA MEASUREMENTS i
Most Recent Mean Federal Drinking Water Std.
MW-27 81 pCi/L 32 pCi/L 50 pCi/L MW-45 198 145 50 MW-30 48 52 50 11
Also, data from the Site Characterization Report (SCR) shows that several other wells or piezometers ex.ceeded drinking water standards in the second quarter 1991 sampling. PADEP is aware that ARCO /B&W believes all data from this sampling period is artifactual. However, no adequate documentation has been provided by ARCO /B&W or NRC tojustify the discounting of these data.
In conclusion, PADEP requests that NRC update the tables in the DEIS (August 1997) to include the most recent gross alpha data from the 1995 Field Work Repe s er MW-23 and MW-30. In addition, the text should be edited to correctly discuss the wells and piezometers in which VOCs ware detected and radionuclides were in excess of Federal drinking water standards as noted in tne above tables.
SECTION 3.5.1 RADIOLOGICAL CONTAMINANTS New information has been added to this section. Although the Am and Pu issue in the Trench 10 area is discussed, PADEP notes that there is no mention of criteria exccedences for subsurface soil samples. Also, the section overlooks the issue of total Pu and is restricted to "Pu. PADEP 2
has commented already that compliance with the Pu criterion should be based on total Pu. This can be estimated by using total plutonium to americium ratios determined by alpha spectroscopy from previous data (as discussed on page 1 of the PADEP comment document on the Preliminary DEIS). Discussion of totalPu was not incorporated into the Working DEIS or the DEIS (August,1997).
The issue of the source of radiological constituents in the Trench 10 area is again stated by the DEIS (August,1997) as " storage of equipment on the surface," as has been noted in the DEIS (August,1997) in several sections. PADEP again notes that the available data and information do not identify the source of the Am and Pu. Six out of seven of the grid locations having the highest average Am-241 concentrations are very near the trench. Little contamination was found along the road, where one would expect facility equipment to be parked. Also, no data are available regarding the levels of Am-241 at depth in the trench area, except the 1993 data showing contamination at depth within the trench As noted elsewhere in these comments, PADEP is concerned that the DEIS (August 1997) has restated ARCO /B&W's statements and has not based its conclusions on the data.
Lastly, Section 3.5.1 discusses the very high gross alpha measurement for a particular leachate sample from Trench 3 (29,500 pCi/L). This high reading was characterized as being "of highly questionable validity" on the basis that "the actual gross alpha level was about 5,100 pCi/L."
Consequently, NRC did not include the 29,500 pCi/L value in characterizing the source. PADEP has already requested the source of the alternate, lower gross alpha reading so that it can be reviewed. The requested information was not provided in the DEIS (August 1997).
In conclusion, PADEP requests that NRC include a discussion of total Pu isotopes, remove its i
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conclusion that equipment storage is the source of Am and Pu in the trench area, and provide the basis for its conclusions about the 29,500 pCi/L trench leachate gross alpha reading.
SECTION 4.1.3.1 GROUNDWATER (NO ACTION)
PADEP continues to request that NRC provide data to demonstrate that fracture flow is not likely to occur at the site. On page 4-9, NRC states that a third scenario was evaluated "to account for possible fracture flow," but this scenario is then dismissed as not being realistic for the Parks site.
For instance, on page 3-59 (Section 3.5.1.3), NRC states: "the staff does not expect the uranium to move outside of the trenches into the shallow bedrock aquifer during the period of regulatory performance (1000) years." The conclusion can only be drawn if the fracture flow 's assumed not to occur and the third scenario described on page 4-9 is dismissed as unrealistic for the site.
liowever, on page 4-8, NRC gives evidence that fracture flow does occur at the site:
The shallow bedrock is described as having little primary porosity, with groundwater flow and storage mostly in secondary features such as fractures, joints, and dissolution cavities (ARCO /B&W 1994). Wells drilled on the site close to one another often yielded different quantities of water, suggesting that water was being carried in discrete fractures.
Measured permeabilities from well tests showed some values substantially higher than the j
mean, which may indicate that these wells intercept fractures with higher permeabilities than the rock matrix.
PADEP thus requests that NRC either remove ali :tatements in the DEIS (August,1997) that the groundwater exposure pathway is unrealistic and instead present groundwater exposures as reasonable future exposure pathways or present the data and evidence that can support a change in the evaluation of the likelihood of fracture flow at the site. At this time, the DEIS (August, 1997) is not consistent. If fracture flow is likely or possible, then radiation doses from ingestion of groundwater from on-site wells in the shallovt bedrock are possible within the next 1,000 years.
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If, on the other hand, fracture flow is extremely unlikely, then retardation delays non-zero groundwater ingestion doses to periods of time beyond 1,000 years. The evaluation of fracture flow is a critical risk assessment issue that continues to be unexplained in the DEIS (August, 1997).
SECTION 4.1.3.2 SURFACE WATER (NO ACTION)
NRC states that " contaminated surface seeps on Dry Run would produce a localized impact on surface water. Seeping groundwater contaminated with uranium [up to 40 pCi/L (1.5 Bq/L); see groundwater modeling analysis, Appendix E] would be diluted by a factor of 1,000 or more.. "
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PADEP ncces that this same statement appeared in the Working DEIS, except that the uranium j
concentrat'on was 80pCi/L {This same discrepancy is noted in Section 4.1.6.1.) PADEP has i
evaluated Appendix E in both documents and finds that the analysis, the assumed equations, and the input parameters were identical in the two documents. In addition, the results presented for i
l hypothetical on-site wells are identical for the two documents. Thus, PADEP is puzzled as to
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why the surface seep result differs between the two documents. In addition, PADEP does not find any reference to the basis for the dilution factors cited in this section.
NRC states in this section that uranium concentrations in Carnahan Run " would be diluted to levels below detection limits." However, radiological constituents were detected in samples taken of water from Carnahan Run at levels exceeding typical background levels in surface waters (19 pCi/L). This level also exceeds the EPA drinking water standard. Although the radioactivity may be associated with naturally occurring uranium in coal mines, it may also have originated from the migration of trench leachate. Alpha spectroscopy, which was requested by PADEP and promised by ARCO /B&W, was not performed on the water samples from Carnaham Run. This method would have provided the information required to evaluate the source of the detected radioactivity.
PADEP requests that NRC explain why the results of the groundwater modeling analysis changed from 80 pCi/L to 40 pCi/L even though there were no documented changes in input parameters or other assumptions. The source of the 40 pCi/L value should also be identified. No i
documentation of this value can be found in Appendix E. PADEP also requests that the dilution j
l factors be described as qualified estimates with no specific basis in site data. Given the actual presence of radioactivity in Carnahan Run and the lack of supporting data to determine its source, PADEP requests that NRC modify the above-quoted statement. The statement is not consistent with site measurement data.
SECTION 4.1.5 IIUMAN IIEALTII(NO ACTION) j i
NRC in this section again miscites the allowable concentrations of radiological constituents when decommissioning a site. 100 mrem / year is cited as the limit for total effective dose equivalent to an individual member of the public from operation of a licensed facility (10CFR20.1301). This limit is not relevant to a decommissioned facility. The relevant criteria are the ones recently published by NRC.
On May 21,1997 NRC approved maximum permissable radiation levels for license termination.
The permissable level for unrestricted release is "as far below 25 millirems per year as is reasonably achievable." For restricted release, the permissable level is "as low as is reasonably achievable," and legally enforceable institutional controls must " ensure that the dose does not exceed 25 millirems per year." The limit of 100 mrem / year is the maximum dose level that cannot be exceeded "if the institutional controls were no longer in effect."
PADEP requests NRC to clarify current, applicable public exposure limits for restricted release and state that the applicable goal is "as low as is reasonably achievable" and not exceeding 25 mrem / year with institutionalcontrols.
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4 NRC states in,this section (page 4-10 and 4-11) that the groundwater pathway is not credible at l
the site. Accordingly, the dose assessment for an inadvertent intmder excludes the groundwater pathway entirely. PADEP has commented repeatedly that such an assumption is tied to the issue of fracture flow, which has previously been concluded to be relevant to the site. Furthermore, NRC states in Section 4.1.3.2 that groundwater could be contaminated with uranium up to 40 1
pCi/L, which would exceed the Federal drinking water standard. PADEP is curious as to how NRC can conclude that groundwater can be expected to have uranium concentrations exceeding the drinking water standard and also exclude the drinking v/ater pathway as "not credible."
In conclusion, PADEP requests NRC to clarify the applicable dose limits for unrestricted site decommissioning. Also, PADEP requests that the dose estimation process include the groundwater ingestion pathway because NRC's own methods estimate that uranium can be expected at levels exceeding the drinking water standard at certain on-site locations. The groundwater pe way should not be excluded unless there is clear and convincing evidence that fracture flow does not and cannot occur.
SECTION 4.2.3.1 GROUNDWATER (SIP)
In this section, it is stated that some of the engineered features of the SIP alternative will fail within the 1,000 year analysis period. When commenting on the Preliminary and Working DEIS, PADEP requested that this section be expanded to provide information about future monitoring and repairs or modification of the engineered features. This information was not provided in the DEIS (August,1997).
PADEP notes that NRC estimates uranium concentrations in gmundwater for this option "at 1
concentrations less than 40 pCi/L (1.5 Bq/L) previously predicted in the no action alternative. As noted elsev here, this statement indicates that dose assessment should include the groundwater ingestion pathway, and not exclude it as was done by NRC.
PADEP requests that NRC include groundwater exposure pathways in its dose estimation process.
SECTION 4.2.3.2 SURFACE WATER (SIP)
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It is stated in this section that uranium from mine drainage is "already diluted to below detection limits" and would be "further diluted by runoff by Carnahan Run.. " PADEP notes that radiological constituents were detected in samples taken of water from Carnahan Run at levels exceeding typical background levels in surface waters (19 pCi/L). This level also exceeds the EPA drinking water standard. Thus, PADEP requests that NRC remove this erroneous statement.
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SECTION 4.2.5.I RADIOLOGICAL IMPACTS (SIP)
This section states again that "the public would not be exposed to radionuclides by the drinking water pathway" because of retardation of uranium migration due to adsorption onto soil and bedrock. As notw in Section 4.2.3.1, however, NRC estimates uranium in groundwater for this option "at concentrations less than 40 pCi/L (1.5 Bq/L) previously predicted in the no action l
alternative." As noted elsewhere, this statement indicates that dose assessment should include the groundwater ingestion pathway, and not exclude it as was done by NRC. PADEP requests that l
NRC include groundwater exposure pathways in its dose estimation process.
SECTION 4.3.5.2 CHEMICAL HAZARD ASSESSMENT (SIP)
PADEP previously commented that Section 3.5.2.1 erroneously concluded that chemical concentrations were declining. Data was presented showing that they were not declining.
PADEP thus requests that the statement that impacts will" continue to decrease" be removed.
SECTION 4.2.8.3 MITIGATION BY USE OF INSTITUTIONAL CONTROLS (SIP)
PADEP assumes that the Federal government would assume ownership of the site, not the Commonwealth of Pennsylvania. PADEP requests that reference to the Commonwealth be removed from the document.
SECTION 4.3.5 HUMAN HEALTH (DOS)
This vction states that " uranium has not been detected in sampling wells outside of the trenches."
The statement is incorrect. Elevated levels of alpha and/or beta activity have been detected in the following locr.Gons: PZ2, PZ6, MW-27, MW-20, MW-23, MW.30 and MW-45.
PADEP requests that NRC change the incorrect statement.
SECTION 4.3.5.I RADIOLOGICAL DOSE TO WORKERS (DOS)
PADEP notes that the estimation of respirable dust concentrations to workers is flawed. Based on experience with fugitive dust generation models, PADEP finds it impossible to believe that the average respirable dust concentration over the construction period would be 8,000 ug/m'. NRC gives no support for the estimate except to reference Section 2.4.2, which does not, in fact, discuss the estimate.
In addition, PADEP has discovered an error in the calculation. The second equation on page 4-32 should have 4.00 x 10' g in the numerator, instead of 1.44 x 10' g. In the previous paragraph the total dust is stated as 13,000 kg and the fraction of total dust that is respirable is 30%. Even with this error corrected, the corrected estimated average respirable dust concentration of 2,220 l
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f ug/m' is still unbelievable. Monitoring of respirable dust at construction sites during very dusty conditions has been reported in the literature, and the highest measured values are in the 100's of ug/m', not 1,000's. PADEP believes that the NRC's estimate of worker dose should be <25 mrem / year based on respirable dust inhalation.
PADEP requests that NRC perform fugitive dust modeling with standard emission factors and document the effort in a fully transparent fashion so that reviewers can evaluate the me del, the algorithms, and the input parameters.
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SECTION 5 COSTS AND BENEFITS OF THE DECOMMISSIONING ALTERNATIVES Many of PADEP's comments to this section of the Preliminary DEIS and the Working DEIS have j
been incorporated into the DEIS (August,1997). In PADEP's opinion, the costs of the DOS option were greatly exaggerated. Several examples were listed with a rationale for PADEP'c conclusion that the cost elements were higher than reasonable. In the Working DEIS and the DEIS (August,1997), NRC agrees with PADEP that the ARCO /B&W cost estimate was not reasonable.
PADEP also notes that the Working DEIS gives estimates of the benefits of the various options.
The societal benefits associated with the No Action Option is $0. The benefits of the DOS i
Option is $1,231,000,000 over 500 years. The benefits of the MSIP Option are $616,000,000 to
$1,158,000,000. Thus, the benefits are greater for the DOS option. The benefit to cost ratio is also greater for the DOS Option assuming that the lower estimate of total benefits is correct: 30 compared to 18. With the higher estimate of benefits for the SIP Option, the benefit to cost ratio is comparable between the options.
SECTION 5.1 COSTS OF ALTERNATIVES ARCO /B&W did not provide any estimates of the costs associated with long-term maintenance after 30 years. Clearly, such surveillance and maintenance will be required for a very long period of time. In the Preliminary DEIS, the NRC made an estimate of $1,000,000 for the present worth estimate for such maintenance for the SIP and SOS options. At that time, PADEP stated that this amount appeared to be insufficient for the long time periods during which maintenance will be required for these two options. In the Working DEIS, NRC modified its estimated costs for this requirement downward to $600,000 in 1997 dollars. The value estimated in the DEIS (August, 1997) is $1,500,000._As noted in comments to section 2.2.9, PADEP believes that these costs are inappropriately low.
PADEP is also puzzled about the addition of $100,000 in surveillance and maintenance costs for the DOS option. If the waste is removed in the DOS option, why is this cost necessary?
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SECrl,0N 5.2 BENEFITS OF ALTERNATIVES The NRC analysis indicates that in all cases analyzed the benefits of the DOS option far exceed the benefits of the other options considered. The present value of benefits over 50 years is $97 million and over 500 years is $245 million, assuming a 1 percent discount rate. These values exceed the benefits of the SIP and SOS options by $39 million to $64 million over 50 years and
$64 million to $123 million over 500 years, and the no action alternative which has $0 in benefits.
Given that the costs of the project would be borne by the licensee and the majority of the bene 6ts would accrue to the residents of Parks Township and surrounding areas, it is not clear how the benefits analysis was used in the evaluation process. PADEP requests that NRC explain how benefits were used in the analysis of the selected alternative (see also discussion below).
PADEP also notes that the DOS option is stated to increase land for commercial use by only 15 acres. This benefit of the DOS option appears to be underestimated.
SECTION 6 STAFF ASSESSMENT Human HealN Canmens NRC states again in Section 6 that VOCs are declining in concentration. As noted elsewhere, site data do not support the conclusion that concentrations are decessing. Also, the statement is made that off-site radiological doses are zero, despite the fact that radionuclides activity was detected in Carnahan Run, and the DEIS estimates that groundwater seeps near Dry Run'would contain radioactivity in excess of federal drinking water standards. NRC's comparison of dose estimates then totally ignores groundwater doses.
PADEP disagrees with NRC that off-site doses are higher for DOS than for No Action, SIP, or
' Modified SIP. This conclusion can only be made if one totally ignores groundwater doses, as noted above. PADEP notes again that groundwater exposure would be a credible pathway if fracture flow were occurring or might occur in the future. ARCO /B&W stated in earlier
- documents that fracture flow might occur, but then concluded based on the 1995 field work that it does not and would not occur. NRC apparently also believes that fracture flow is not relevant.
However, PADEP has repeatedly requested that ARCO /B&W and NRC simply provide the basis for this conclusion for PADEP's evaluation. This issue is a critical one for performing a risk assessment for the site, and PADEP is entitled to see an analysis of current site data that supports the dismissal of fracture flow as a relevant site issue.
PADEP also disagrees with the statement on page 6-1 regarding the DOS option that: "However, there would be increased risks associated with the removal and processing of material from the trenches." The statement refers to the dose estimate in Table 6.2. However, PADEP notes that 1 mrem / year is an overestimate if based on NRC's previous dust estimation method. This method o
was found to be flawed, as noted in previous comments.
In addition, NRC states that the MSIP alternative would be the most protective of public health and the environment and that the No-Action alternative cannot be considered because the doses L
exceed NRC's criteria for unrestricted use. Given that the only improvements to be made to the site under MSIP would be filling the mine void and implementing institutional controls (i.e.
fencing, and deed restrictions), PADEP finda it hard to agree that MSIP is the most protective alternative by including only a fence around the property and having a deed recorded in the Court q
House.
I Cost and Bene)it Commenu The MSIP altemative includes filling the mine void and providing institutional controls to prevent people from living on the site. The option would include provision for a maintenance program to maintain the soil cap in its present condition and to prevent any erosion of the cap caur,ed by mnoff or erosion of Dry Run, and provide for a monitoring program to continue monitoring the wells on-site to ensure off-site doses continue to be negligible. The cost estimate for this
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- 4 alternative identifies costs for the fil2ng of the mine void and the installation of groundwater j
monitoring wells.
. Several construction activities have been eliminated from this option that would appear to provide substantial benefit in preventing or discouraging the inadvertent intmder from entering the trenches. These items include the entire cap construction including the shaping fill, radon barner (replaced with sand / gravel layer or rock layer to discourage entry in the area), geomat, drain sand blanket, biointrusion layer, filter sand, and soil cover. These items or similar construction materials would provide a cover layer that would resist erosion from natural forces and could restrict drilling or excavation into the trenches.
In addition, removal and replacement of the gas line should be included in the estimate
- since maintenance on the gas line will be required at some point in the future, and the line would have to be relocated to prevent esposure to gas line workers. Earthwork and site preparation would also be required for this alternative. In addition, Dry Run relocation and erosion protection rock should be included along with landscaping and the ditch and drainage excavation. Health and Safety / Quality Assurance / Quality control should be consistent with the level of activity identified for the SIP option. Using these assumption the Total Constmetion Cost for this option is $6.139 million not the $2.125 million identified by the NRC. In addition, the Other Costs (Licensee costs) would be similar to the other options considered. The Total Costs in 1998 for the scenario would be $20.839 million versus $23.023 for SIP and $28.284 million for
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DOS (staff estimate).
NRC also estimated the benefits for this option and has assumed that the benefits would be the same as the SIP option. Given that the only remediation of the site would be the filling of the mine void, it is not clear why the benefits would be equal to the SIP alternative where there would be significant structural features added to the site to prevent migration of the radiological material. It would seem more appropriate that the level of benefits would be closer to the No 1
Action alternative since only limited remedial activities would be performed.
- Even with the NRC's s,ssumptions regarding the level of construction reactivities, the option with the greatest benefits is still the DOS option (staff estimate). The PADEP is curious why this option was not selected, since this option has the greatest benefits of all options considered and has costs that are similar to SIP or MSIP.
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I APPENDIX C Section C.3 -
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Further documentation is needed to explain how the value for TD/UD,340(1+230/0.68) was -
' obtained. PADEP requests that this information be provided.
1 On page C-14,- NRC refers to the pathways listed in Table C-6. PADEP believes that the proper table reference is Table C-7.
ora page C-14, the equation at the end of Section C.3 is out of place. It should be moved to the locatioidf the missing equation in Section C.3,1.
. APPENDIX E - LONG-TERM DOSE ASSESSMENT NRC states in this appendix that one of the fixed parameters for the analysis is the concentrations measured in TWSPs. However, the actual values used in the modeling effort are not listed. Thus, PADEP is unable to evaluate the effort.
PADEP requests that NRC list the actual source terms values in a table within Appendix E.
The conclusion of the modelling when retardation is assumed for soil, weathered, and the aquifer is that no wells' will contain uranium in 1,000 years. However, actual measurements froin monitoring wells demonstrate elevated radiological activity in several wells (MW-20, -23, -27, -
30, -45). How does NRC reconcile a model of radiological contaminant migration that predicts zero concentrations 1,000 years in the future with actual measurements as high as 86 pCi/L for alpha activity and 198 pCi/L for beta activity?
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