ML20120A220
| ML20120A220 | |
| Person / Time | |
|---|---|
| Site: | 07000925 |
| Issue date: | 04/29/2020 |
| From: | Lux J Environmental Properties Management |
| To: | Davis P, Robert Evans, Kenneth Kalman Document Control Desk, Office of Nuclear Material Safety and Safeguards, State of OK, Dept of Environmental Quality (DEQ) |
| References | |
| Download: ML20120A220 (13) | |
Text
April 29, 2020 Mr. Ken Kalman U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Paul Davis Oklahoma Department of Environmental Quality 707 North Robinson Oklahoma City, OK 73101 Mr. Robert Evans U.S. Nuclear Regulatory Commission 1600 East Lamar Blvd; Suite 400 Arlington, TX 76011-4511 Re: Docket No.70-925; License No. SNM-928 EPA Calculation of Maximum Contaminant Level for Technitium-99
Dear Sirs:
In a letter dated April 20, 2020, the Oklahoma Department of Environmental Quality (DEQ) commented on the following two documents submitted by Environmental Properties Management LLC (EPM) Solely as Trustee for the Cimarron Environmental Response Trust (CERT).
- 1. Technitium-99 Groundwater Assessment, submitted January 31, 2020
- 2. Revised Evaluation of the Need to License Tc-99, submitted March 10, 2020 The DEQs only comment on Technitium-99 Groundwater Assessment read, The Assessment Report cites a Primary Drinking Water Standard or Maximum Contaminant Level (MCL) of 900 picoCuries per liter (pCi/1) for Tc-99. Please provide a reference.
Attached please find a November 6, 2001 memorandum issued by then-acting director of the US Environmental Protection Agency (EPA) to provide guidance to regional office personnel regarding MCLs for radionuclides. The memorandum explains that for beta emitters, the EPAs MCL is a concentration that produces a dose equivalent of 4 mrem/yr or less to the total body or any internal organ for the sum of the doses from man-made beta particles and photon emitters.
Attachment B to the memorandum is a list of radionuclide concentrations calculated by EPA based on the 4 mrem/yr standard. Attachment B cites a value of 900 pCi/l for Tc-99.
9400 Ward Parkway
- Kansas City, MO 64114 Tel: 405-642-5152
- jlux@envpm.com
Mr. Paul Davis April 29, 2020 Page 2 Should you desire additional information, please feel free to contact me at 405 642-5152 or jlux@envp.com.
Sincerely, Jeff Lux, P.E.
Trustee Project Manager Attachment cc: Michael Broderick, DEQ (electronic copy)
NRC Public Document Room (electronic copy)
ATTACHMENT NOVEMBER 6, 2001 EPA GUIDANCE DERIVATION OF REMEDIATION GOALS FOR RADIONUCLIDES IN GROUNDWATER
Directive no. 9283.1-14 MEMORANDUM
SUBJECT:
Use of Uranium Drinking Water Standards under 40 CFR 141 and 40 CFR 192 as Remediation Goals for Groundwater at CERCLA sites FROM: Elaine F. Davies, Acting Director Office of Emergency and Remedial Response (OERR)
Office of Solid Waste and Emergency Response Stephen D. Page, Director Office of Radiation and Indoor Air (ORIA)
Office of Air and Radiation TO: Addressees PURPOSE This memorandum addresses the use of uranium standards in 40 CFR Part 141 and 40 CFR Part 192 when setting remediation goals for ground waters that are current or potential sources of drinking water at Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) sites. Todays memorandum will be of interest to site decisionmakers that have uranium as a contaminant of concern in groundwater at their CERCLA site.
This document provides guidance to Regional staff, in dealing with the public and the regulated community, regarding how EPA intends to implement the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). It describes national policy. This document is not a substitute for EPA's statutes or regulations, nor is it a regulation itself. Thus, it cannot impose legally-binding requirements on EPA, States, or the regulated community, and may not apply to a particular situation based upon the circumstances.
BACKGROUND All remedial actions at CERCLA sites must be protective of human health and the environment and comply with applicable or relevant and appropriate requirements (ARARs) unless a waiver is justified. Cleanup levels for response actions under CERCLA are developed based on site-specific risk assessments, ARARs, and/or to-be-considered material1 (TBCs).
The determination of whether a requirement is applicable, or relevant and appropriate, must be made on a site-specific basis (see 40 CFR §300.400(g)).
CERCLA GROUNDWATER PROTECTION EPA expects to return usable ground waters to their beneficial uses whenever practicable. (see 40 CFR §300.430(a)(1)(iii)(F)). In general, drinking water standards provide relevant and appropriate cleanup levels for ground waters that are a current or potential source of drinking water. However, drinking water standards generally are not relevant and appropriate for ground waters that are not a current or potential source of drinking water (see 55 FR 8732, March 8, 1990). Drinking water standards include federal maximum contaminant levels (MCLs) and/or non-zero maximum contaminant level goals (MCLGs) established under the Safe Drinking Water Act (SDWA), or more stringent state drinking water standards. Other regulations may also be ARARs as provided in CERCLA §121(d)(2)(B).
The Agency issued guidance concerning ground water use determinations in a memo from Office of Solid Waste and Emergency Response Assistant Administrator to the Regions entitled The Role of CSGWPPs in EPA Remediation Programs (OSWER Directive 9283.1-09), April 4, 1997. This guidance states that EPA generally defers to State determination of current and future groundwater uses, when the State has a Comprehensive State Ground Water Protection Program (CSGWPP) that has been endorsed by EPA and has provisions for site-specific decisions. For States that do not have an EPA-endorsed CSGWPP (or whose CSGWPPs do not have provisions for making site-specific determinations of groundwater use, resource value, priority or vulnerability), EPA uses either EPA Guidelines for Ground-Water Classification (Final Draft, December 1986), or State groundwater classifications or similar State designations, whichever classification scheme leads to more stringent remediation goals.
1 To-be-considered material, TBCs include non-promulgated advisories or guidance issued by Federal or State governments that are not legally binding and do not have the status of potential ARARs. However, TBCs should be considered along with ARARs as part of the site risk assessment and may be used in determining the necessary level of cleanup for protection of health and the environment.
MASS AND ACTIVITY (pCi/L and µg/L)
Concentrations of radionuclides in water are typically expressed in terms of activity of the radionuclide per unit of volume in the water (e.g., picocuries per liter or pCi/L). Activity measures the rate of disintegration of a radionuclide per unit mass (for soil, sediment, and foodstuffs) or volume (for air and water). Because the carcinogenic effect of a radionuclide is due to its disintegration rate, which occurs during its decay process, concentrations of radionuclides are generally measured in terms of activity for health evaluation purposes.
Uranium is the only radionuclide for which the chemical toxicity has been identified to be comparable to or greater than the radiotoxicity, and for which a reference dose (RfD) has been established to evaluate chemical toxicity. The RfD is an estimate of a daily ingestion exposure to the population, including sensitive subgroups, that is likely to be without an appreciable risk of deleterious effects during a lifetime. Uranium in soluble form is a kidney toxin. The relative risk of uranium kidney toxin effects correspond to the level of exposure to the uranium mass concentrations; the oral RfD of uranium is expressed in terms of mass (0.6
µg/kg/day).
RADIONUCLIDE MCLs On July 9, 1976, EPA promulgated 40 CFR Part 141 Drinking Water Regulations:
Radionuclides (1976 MCL rule). This 1976 MCL rule included the following MCLs: 5 pCi/L for radium-226 and radium-228 combined; 15 pCi/L for gross alpha particle activity (including radium 226, but excluding uranium and radon); and a concentration that produces a dose equivalent of 4 mrem/yr or less to the total body or any internal organ for the sum of the doses from man-made beta particles and photon emitters. A list of radionuclides that are addressed by the gross alpha MCL are provided in Attachment A to todays memorandum. Also, provided in Attachment B to todays memorandum is a list of radionuclide concentrations calculated using the 4 mrem/yr beta particles and photon emitters MCL standard.
On December 7, 2000, EPA amended 40 CFR Part 141 (65 FR 76708, December 7, 2000) National Primary Drinking Water Regulations; Radionuclides (2000 MCL rule).
This 2000 MCL rule established requirements for uranium, and retained the existing requirements for combined radium-226 and radium-228, gross alpha particle radioactivity, and beta particle and photon radioactivity. The 2000 MCL rule did include MCLGs of zero for the last four contaminants (see 40 CFR § 141.55).
The 2000 MCL rule established an MCL for uranium of 30 micrograms per liter (µg/L).
For the MCL rulemaking, EPA assumed a typical conversion factor of 0.9 pCi/µg for the mix of uranium isotopes found at public water systems, which means that an MCL of 30 µg/L will typically correspond to 27 pCi/L. EPA considered the 30 µg/L level (which corresponds to a 27 pCi/L level) to be appropriate since it is protective for both kidney toxicity and cancer.
However, the relationship between mass concentration (µg/L) and activity (pCi/L) is dependent upon the relative mix of the radioactive isotopes (e.g., uranium-234, uranium-235, uranium-238) that comprise the uranium at a particular drinking water source.2 In circumstances with more extreme conversion factors (> 1.5 pCi/µg), uranium activity levels may exceed 40 pCi/L.
In these circumstances, EPA recommends in the 2000 MCL rule that drinking water systems mitigate uranium levels to 30 pCi/L or less, to provide greater assurance that adequate protection from cancer health effects is being afforded (see 65 FR at page 76715).
UMTRCA GROUNDWATER STANDARDS On January 11, 1995, EPA promulgated 40 CFR Part 192 (60 FR 2854, January 11, 1995) Groundwater Standards for Remedial Actions at Inactive Uranium Processing Sites (UMTRCA rule).3 Included in these standards is a constituent concentration limit for the combined level of uranium-234 and uranium-238 in groundwater. These standards were developed specifically for the cleanup of uranium mill tailings at 24 sites designated under Section 102(a)(1) of UMTRCA (Title I sites). The list of 24 Title I sites is a closed set chosen in 1979 that cannot be expanded without congressional action. The standards were developed to ensure that all currently used and reasonably expected drinking water supplies near these 24 sites, both public and private, are adequately protected for use by present and future generations. The concentration limit for the combined level of uranium-234 and uranium-238 is 30 pCi/L.
IMPLEMENTATION The following subsections will clarify the use of standards under 40 CFR Part 141 and 40 CFR Part 192 as ARARs when setting remediation levels for uranium in groundwater at CERCLA sites.
MCLs AND UMTRCA AS APPLICABLE REQUIREMENTS The uranium drinking water standards contained within 40 CFR Part 141 are potentially applicable requirements only for community water systems designated under § 141.26 (see 65 FR 76708, 76748 (December 7, 2000)). The uranium groundwater standards contained within 2
For further discussion of mass and activity, including the formula to convert between the two measurement units, see U.S. EPA Radiation Risk Assessment At CERCLA Sites: Q & A EPA 540/R/99/006, December 1999, pp. 5-6.
3 These standards were developed pursuant to Section 275 of the Atomic Energy Act (42 U.S.C. 2022), as amended by Section 206 of the Uranium Mill Tailings Radiation Control Act of 1978 (42 U.S.C. 7918) (UMTRCA).
40 CFR Part 192 are potentially applicable requirements only for the 24 Title I sites designated under Section 206 of UMTRCA.
MCLs AND UMTRCA AS RELEVANT AND APPROPRIATE REQUIREMENTS In general, because the MCLG is zero for the radionuclides included in 40 CFR Part 141, the MCLs for these radionuclides are potentially relevant and appropriate requirements at sites with radioactive contamination in groundwaters that are current or potential sources of drinking water. In particular, the uranium MCL of 30 µg/L is a potentially relevant and appropriate requirement for groundwaters that are current or potential sources of drinking water that have any of the uranium isotopes as a contaminant of concern.
Thus, for these radionuclides, the MCL concentration of 30 µg/L is generally used as the cleanup level for groundwater that is a current or potential source of drinking water, and is to be attained throughout the plume at the completion of the response action.
If either uranium-234 or uranium-238 is a contaminant of concern in ground waters that are current or potential sources of drinking water, and the site is not a Title I UMTRCA site, then the uranium UMTRCA standard under 40 CFR Part 192 of 30 pCi/L is a potentially relevant and appropriate requirement. Please note that this means both the uranium MCL (40 CFR Part 141) and the uranium UMTRCA (40 CFR Part 192) standards may be selected as relevant and appropriate requirements for addressing uranium contamination in ground water at the same CERCLA site. Since both standards establish levels of uranium in groundwater that are acceptable for drinking, EPA would expect that whenever the uranium UMTRCA ground water standard is a relevant and appropriate requirement, the uranium MCL will also be a relevant and appropriate standard. Selecting both the MCL and UMTRCA standards will ensure that the kidney toxicity and carcinogenic health effects posed by uranium are adequately addressed.
MCL PREAMBLE AS A TO-BE-CONSIDERED In addition, the preamble recommendation to public water systems concerning extreme pCi/µg conversion factors in the uranium 2000 MCL rulemaking may be a TBC. In situations where the mix of uranium isotopes means that attaining the uranium MCL of 30 µg/L may result in residual activity levels of uranium of greater than 40 pCi/L for total uranium, and a site-specific risk assessment demonstrates that 30 pCi/L is protective, then we recommend 30 pCi/L as a suitable cleanup level in addition to 30 µg/L. This recommendation is made to ensure an equivalent level of protection from the carcinogenic effects of uranium at CERCLA sites and public water systems, and is therefore consistent with the recommendation made in the preamble to the 2000 MCL rule.
CONDUCTING GROUNDWATER RESPONSES FOR 40 CFR PART 141 AND/OR 40 CFR PART 192 ARAR COMPLIANCE When either the uranium MCL and/or the 30 pCi/L uranium UMTRCA standard is considered a relevant and appropriate requirement, or the preamble to the uranium 2000 MCL rulemaking is a TBC, then CERCLA response actions should be conducted using the approach found in the NCP and Superfund guidance (e.g.,
determining groundwater use, point of compliance, areas of flexibility). Because the CERCLA approach for attaining the uranium MCL is more stringent than the UMTRCA approach 40 CFR Part 192, using the CERCLA approach automatically insures compliance with the UMTRCA groundwater standard as an ARAR. For example, the CERCLA approach for complying with the MCL throughout the plume is more stringent than the UMTRCA approach of complying with the groundwater standard only in the uppermost aquifer. Thus if an MCL is attained throughout the plume, the groundwater standard will also be attained in the uppermost aquifer. Key documents that include guidance on the Superfund approach to evaluating and remediating groundwater include: Presumptive Response Strategy and Ex-Situ Treatment Technologies for Contaminated Ground Water at CERCLA Sites (OSWER Directive No.
9283.1-12), October 1996; The Role of CSGWPPs in EPA Remediation Programs (OSWER Directive No. 9283.1-09), April 4, 1997, and; the Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites (OSWER Directive No. 9200.4-17P), April 21, 1999). These and other Superfund groundwater guidance documents may be found on the Internet at:
http://www.epa.gov/superfund/resources/gwdocs/index.htm.
Guidance documents that address establishing contaminant levels in soil to protect groundwater include: Soil Screening Guidance for Radionuclides: Users Guide (OSWER Directive No. 9355.4-16A), October 2000, and Soil Screening Guidance for Radionuclides:
Technical Background Document (OSWER Directive No. 9355.4-16), October 2000.
These Superfund guidance documents may be found on the Internet at:
http://www.epa.gov/superfund/resources/radiation/radssg.htm.
FURTHER INFORMATION The subject matter specialist for this directive is Stuart Walker of OERR 703-603-8748. General questions about this directive, should be directed to 1-800-424-9346.
Addressees:
National Superfund Policy Managers, Regions 1-10 Superfund Branch Chiefs, Regions 1-10 Superfund Branch Chiefs, Office of Regional Counsel, Regions 1-10 Radiation Program Managers, Regions 1, 4, 5, 6, 7, 10 Radiation Branch Chief, Region 2 Residential Domain Section Chief, Region 3 Radiation and Indoor Air Program Branch Chief, Region 8 Radiation and Indoor Office Director, Region 9 Federal Facilities Leadership Council OERR Center Directors OERR NARPM co-chairs OERR Records Manager cc:
Jim Woolford, FFRRO Elizabeth Cotsworth, OSW Craig Hooks, FFEO Barry Breen, OSRE Joanna Gibson, HOSC/OERR Earl Salo, OGC Jeff Josephson, Region 2 Attachment A: List of Man-made and Naturally-Occurring Radionuclides addressed by 15 pCi/L gross alpha particle activity MCL standard4 Nd-144 Ra-219 U-235 Sm-147 Ra-223 U-236 Sm-148 Ra-224 U-238 Po-208 Ra-226 Pa-231 Bi-210 Rn-220 Pu-236 Bi-211 Fr-221 Pu-238 Bi-212 Fr-223 Pu 239 Bi-213 Ac-225 Pu-240 Bi-214 Ac-227 Pu-241 Po-210 Th-227 Pu-242 Po-212 Th-228 Np-237 Po-213 Th-229 Am-241 Po-214 Th-230 Cm-242 Po-215 Th-232 Cm-244 Po-216 U-230 Cm-245 Po-218 U-232 Cm-248 At-217 U-233 Bk-248 At-218 U-234 Cf-250 Tl-217 This list includes only those radionuclides with half lives exceeding 4 days .
4 Attachment B: List of Radionuclides addressed by 4 mrem/yr man-made beta particles and photon emitters MCL standard5 Nuclide pCi/l Nuclide pCi/l Nuclide pCi/l Nuclide H-3 20,000 Sr-85 m 20,000 Sb-124 60 Er-169 300 Be-7 6,000 Sr-85 900 Sb-125 300 Er-171 300 C-14 2,000 Sr-89 20 Te-125m 600 Tm-170 100 F-18 2,000 Sr-90 8 Te-127 900 Tm-171 1,000 Na-22 400 Sr-91 200 Te-127m 200 Yb-175 300 Na-24 600 Sr-92 200 Te-129 2,000 Lu-177 300 Si-31 3,000 Y-90 60 Te-129m 90 Hf-181 200 P-32 30 Y-91 90 Te-131m 200 Ta-182 100 S-35 500 Y-91m 9,000 Te-132 90 W-181 1,000 inorg Cl-36 700 Y-92 200 I-126 3 W-185 300 Cl-38 1,000 Y-93 90 I-129 1 W-187 200 K-42 900 Zr-93 2,000 I-131 3 Re-186 300 Ca-45 10 Zr-95 200 I-132 90 Re-187 9,000 Ca-47 80 Zr-97 60 I-133 10 Re-188 200 Sc-46 100 Nb-93m 1,000 I-134 100 Os-185 200 Sc-47 300 Nb-95 300 I-135 30 Os-191 600 Sc-48 80 Nb-97 3,000 Cs-131 20,000 Os-191m 9,000 V-48 90 Mo-99 600 Cs-134 80 Os-193 200 Cr-51 6,000 Tc-96 300 Cs-134m 20,000 Ir-190 600 Mn-52 90 Tc-96m 30,000 Cs-135 900 Ir-192 100 Mn-54 300 Tc-97 6,000 Cs-136 800 Ir-194 90 Mn-56 300 Tc-97m 1,000 Cs-137 200 Pt-191 300 Fe-55 2,000 Tc-99 900 Ba-131 600 Pt-193 3,000 Fe-59 200 Tc-99m 20,000 Ba-140 90 Pt-193m 3,000 Co-57 1,000 Ru-97 1,000 La-140 60 Pt-197 300 Co-58 300 Ru-103 200 Ce-141 300 Pt-197m 3,000 Co-58m 9000 Ru-105 200 Ce-143 100 Au-196 600 Co-60 100 Ru-106 30 Ce-144 30 Au-198 100 Ni-59 300 Rh-103m 30,000 Pr-142 90 Au-199 600 Ni-63 50 Rh-105 300 Pr-143 100 Hg-197 900 Ni-65 300 Pd-103 900 Nd-147 200 Hg-197m 600 Cu-64 900 Pd-109 300 Nd-149 900 Hg-203 60 Zn-65 300 Ag-105 300 Pm-147 600 Tl-200 1,000 Zn-69 6,000 Ag- 90 Pm-149 100 Tl-201 900 110m Zn-69m 200 Ag-111 100 Sm-151 1,000 Tl-202 300 Ga-72 100 Cd-109 600 Sm-153 200 Tl-204 300 5
For those isotopes where an MCL is calculated, concentration values were rounded using the same format as EPA guidance for the 1976 MCL rulemaking.
Nuclide pCi/l Nuclide pCi/l Nuclide pCi/l Nuclide Ge-71 6,000 Cd-115 90 Eu-152 200 Pb-203 1,000 As-73 1,000 Cd-115m 90 Eu-154 60 Bi-206 100 As-74 100 In-113m 3,000 Eu-155 600 Bi-207 200 As-76 60 In-114m 60 Gd-153 600 Pa-230 600 As-77 200 In-115 300 Gd-159 200 Pa-233 300 Se-75 900 In-115m 1,000 Tb-160 100 Np-239 300 Br-82 100 Sn-113 300 Dy-165 1,000 Pu-241 300 Rb-86 600 Sn-125 60 Dy-166 100 Bk-249 2,000 Rb-87 300 Sb-122 90 Ho-166 90