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~2 Anticipated Inventories of Radioactive or Radioactively Contaminated Materials This chapter summarizes current estimates of the quantities of slightly radio- active solid material (SRSM) expected to arise over the next 25 years from cleanup and decommissioning of licensed nuclear facilities and from other facili- ties that may contain SRSM. These estimated inventories include materials from U.S. Nuclear Regulatory Commission (USNRC)-licensed facilities, from facili- ties licensed by agreement states, and from U.S. Department of Energy (DOE) and Department of Defense (DoD) facilities that do not require a USNRC license. Radioactively contaminated materials known as naturally occurring radioactive material (NORM), naturally occurring and accelerator-produced radioactive ma- terial (NARM), or technologically enhanced NORM (TENORM) also arise from a variety of activities that are not subject to the Atomic Energy Act (AEA) and thus are not regulated by the USNRC. The latter materials are not federally regulated but are regulated by state agencies in some states or not regulated at all in other states. Thus, the USNRC needs to be aware that any new regulations regarding clearance of SRSM could also have impacts on the management of contaminated materials that are currently unregulated at the federal level. Some perspective is also provided in this chapter on the relative fraction of the annual amount of recycled commercial steel scrap that cleared SRSM could comprise if clearance for unrestricted recycle were to be approved. The committee did not find readily available information on inventory and anticipated dates for disposition of radioactive materials. The information cur- rently available covers some industries but not others. In some cases, inventories of radioactive materials have been developed based on what is currently being 55
56 THE DISPOSITION DILEMMA generated from active licensed operations. Other inventories have been devel- oped based on projections of future decommissionings. Inventories for materials that fall outside the legal requirements for radioac- tive waste management are not as carefully developed. The unlicensed industry segments, such as many that produce NORM or TENORM, deal with radioactive material as an unwanted byproduct associated with industrial processes. Inven- tory information about NORM and TENORM tends to focus on the concentra- tions of radium, uranium, or thorium and daughter radionuclides that they con- tain, rather than on total inventories. Therefore, one must often infer or estimate the amount of materials that may satisfy particular clearance criteria based on information created for a different purpose. This chapter relies heavily on a recent report Inventory of Materials with Very Low Levels of Radioactivity Potentially Clearable from Various Types of Facilities, which was prepared for the USNRC by Sanford Cohen & Associates, Inc. (SCA, 2001~. Information from this source has been supplemented with information from various published and Internet sources and from materials pre- sented to the study committee. The characteristics and quantities of radioactive materials used or possessed by USNRC licensees are discussed in the following section. To provide the bases for the cost analysis given in Chapter 4, the emphasis in that section is on radio- active material streams arising from the decommissioning of licensed power reactors. To complete the picture of radioactive materials in the United States, summary information on the other licensed and unlicensed radioactive material streams is presented in the second section. INVENTORIES OF CONTAMINATED MATERIALS ARISING FROM DECOMMISSIONING OF USNRC-LICENSED FACILITIES The majority of USNRC-licensed facilities can be divided into four types, each of which produces a characteristic body of radioactive materials during operations and decommissioning: (1) nuclear reactors (electric power, materials testing, and research reactors); (2) fuel cycle facilities (uranium milling, UFO [uranium hexafluoride] conversion plants, and uranium fuel fabrication); (3) non- fuel-cycle facilities (radioactive material processing, research laboratories, medi- cal treatment, radiography, etc.~; and (4) independent spent fuel storage installa- tions (ISFSIs), which store spent fuel from power reactor operations. Because of the substantial number (more than 100) and large size of electric power reactors, they are the source of about 75 percent of the radioactive materi- als in the United States that require disposal in licensed low-level radioactive waste (LLRW) disposal sites. Power reactors also provide SRSM that is cleared from regulatory control. SRSM arising from the latter three types of facilities is examined in less detail in this report because the quantities of radioactive materi-
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS 57 als arising during operation or during decommissioning are small compared to the quantities arising from power reactor decommissioning. Power Reactors Some data are available for estimating the types and annual quantities of radioactive materials arising from the operation of power reactor facilities that currently dispose of their LLRW at licensed LLRW disposal facilities. Additional data and various estimates are available to define the types and total quantities of radioactive materials resulting from decommissioning power reactor facilities. The decommissioning data and estimates presented in Table 3-1 are derived from two USNRC reports: NUREG/CR-5884 (Konzek et al., 1995) for a reference pressurized water reactor (POOR) and NUREG/CR-6174 (Smith et al., 1996) for a boiling water reactor (BWR). Also presented in the table are estimates of the sums of the quantities of these materials expected to arise from the total U.S. population of power reactors. These population estimates were scaled from the reference reactor quantities using multiplication factors derived from the SCA (2001) report on inventory using the following equations: Mpop.p = MRef.p Ii (Ppi/PRef.p) and Mpop B = MRef B Pi (PB1/PRef.B) where Mpop p and Mpop B are the PWR and BWR population multipliers, respec- tively, MRefp and MRefB are the weights of radioactive materials postulated to arise from decommissioning the reference PWR and BOOR, respectively; PRefp and PRefB are the rated power levels of the reference PWR and BOOR, respec- tively, and Ppi and PBi are the rated power levels of the individual PWRs and BWRs that make up the U.S. population of power reactors. In essence, the popu- lation multiplier for a PWR or BWR represents the number of reference PWRs or BWRs that would contain the same total amount of structural material as is contained within the total populations of PWRs and BWRs that exist currently in the United States. Because many of the reactors are smaller than the reference reactors, the population multipliers are smaller than the actual number of each type of reactor in the total population. For this analysis, the total volume of potential LLRW estimated to arise from decommissioning a power reactor is divided into three categories: (1) activated materials,] including the reactor pressure vessel and internals and the activated portions of the biological shield; (2) nonreusable contaminated materials such as Materials made radioactive through irradiation of stable nuclides by neutrons, protons, electrons, or other particles or radiation.
58 TABLE 3-1 Volume of Materials Arising from Power Reactor Decommissioning (cubic meters) THE DISPOSITION DILEMMA Material Type PWR Volumesa BWRVolumeb Population Totals Activated (LLRW) 547 889 60,900 Nonclearable (LLRW) 1,800 1,520 159,000 Metallic SRSM 5,830 12,700 743,000 Excluded (30%) as LLRW 1,750 3,820 233,000 Net SRSM 4,080 8,900 521,000 Concrete SRSM 69,500 99,700 7,360,000 Total volumes SRSM 73,600 109,000 7,880,000 Population multipliersC 63.76 29.23 NOTE: All values are rounded to three significant figures. aKonzek et al. (1995). bSmith et al. (1996). CData derived from SCA (2001). Each multiplier represents the number of reference reactors of that type that would contain the same total amount of structural material as is contained within the total population of each reactor type. ion-exchange resins, filters, plastics, contaminated equipment insulation, and re- moved contaminated concrete surfaces; and (3) metallic SRSM that might be uncontaminated but is from a radioactive work area or that might be only slightly contaminated. The metallic SRSM includes pool liners, piping, tanks, valves, pumps, heat exchangers, and similar items. Because of the complexity of their inner and outer surfaces, it is difficult to demonstrate that some of these items (such as heat exchangers, pumps, and valves) have been decontaminated suffi- ciently to permit release under a clearance standard. An examination of the tables of system components presented in Konzek et al. (1995) shows that roughly 30 percent of the volume of the metallic SRSM in those tables would probably be excluded on the basis of structural complexity. For this analysis, that 30 percent fraction has been excluded from the volume of SRSM and equipment when calculating the volumes in Table 3-1. The same fraction was assumed to be applicable to the metallic SRSM arising from decommissioning a BOOR. The structural concrete rubble arising from demolition of decontaminated facility structures (clearable concrete) represents the largest single component of the decommissioning wastes. The volumes presented in the table are, for the purposes of analysis, based on the assumption that after contaminated surfaces and activated concrete have been removed, the remaining concrete structures are essentially uncontaminated and may be suitable for clearance or conditional clear- ance (e.g., for reuse in highway construction or other uses, or for disposal in municipal waste Resource Conservation and Recovery Act [RCRAI Subtitle D landfills). The volumes of concrete SRSM rubble are larger than the combined
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS TABLE 3-2 Weights of Slightly Radioactive Solid Material from Power Reactors (metric tons) 59 Material Type PWR Weights BWR Weights Population Totals Metallic SRSM 7,860 18,700 1,050,000 Excluded as LLRW (30%) 2,360 5,610 315,000 Net metallic SRSM 5,500 13,100 735,000 SRSM concretea 83,600 120,000 8,850,000 Total weight SRSM 89,100 133,000 9,590,000 NOTE: Values are rounded to three significant figures and were derived from Konzek et al. (1995) and Smith et al. (1996). aFrom Table 3-1, by assuming that the density of concrete rubble is 1.2 metric tons per cubic meter. volumes of all of the other SRSM by at least a factor of 10. Although it is assumed that beyond the surface, the remainder of the concrete is uncontami- nated, determining what to do with the concrete is complicated by several factors. It can be difficult, in practice, to determine the quantities and levels of radionu- clide contamination that have penetrated into the concrete. There are also sam- pling and analysis costs associated with demonstrating that material is clean, as discussed in Chapter 6 in Measurement Cost. Public perception and regulatory factors can affect choices a licensee makes on disposition of such material, such as whether concrete is left as on-site fill after the license of a site is terminated. The committee was informed that these difficulties with on-site disposal have been encountered with at least one decommissioning of a reactor site, Maine- Yankee. Table 3-2 presents the weights of SRSM and clearable concrete estimated from the reference PWR and BOOR. Population totals assume that the same popu- lation-scalin~ factors anclied to material volumes in Table 3-1 also anclv to material weights. The time distribution of these decommissioning wastes is a significant con- sideration. The quantities of material arising from decommissioning nuclear power reactors will be distributed over an extended period because of the varying dates at which their licenses are scheduled to expire (SCA, 2001, Tables 2-26, 2- 27~. Figure 3-1 illustrates this time distribution for the weight of metallic and concrete SRSM, given the shutdown dates stated in SCA (2001~. If licenses are extended for an additional 20 years, which seems probable for most facilities, the large quantities of material shown in the figure would be generated up to 20 years later, with little material resulting from decommissioning until after 2030. With or without license extensions, the weights of decommissioning mate- rial requiring disposition (about 8 percent metals and 92 percent concrete) range from about 100,000 to more than 1 million metric tons per year during a 25-year
60 THE DISPOSITION DILEMMA 1, 200, 000 - 1, 000, 000 - 800, 000 - 600, 000 - 400, 000 - 200, 000 - I ~ Concrete 111~ Metals ~ . ~ > ~~ ~~ ~~ ~3~ ~3> ~3~ ~~ ~~ ~~ ~~> Year FIGURE 3-1 Time distribution for generation of slightly radioactive solid material from U.S. power reactor decommissionings. SOURCE: Adapted from SCA (2001~. period. The average is around 360,000 metric tons per year, or the equivalent of decommissioning four or five power reactor units per year. If most of the cur- rently operating reactors do receive 20-year license extensions and if the reactors already in safe storage are decommissioned as assumed in SCA (2001), most of the weights shown in Figure 3-1 between 2006 and 2030 would move roughly 20 years into the future, to 2026 to 2050. Relatively small quantities of SRSM from power reactor decommissioning would be generated during the next three de- cades. It is instructive to compare the amount of ferrous metals arising from decom- missioning activities at commercial power reactors with the total amount of fer- rous metal scrap currently being recycled commercially. The committee heard from a representative of a major scrap broker-processor2 that the average amount of obsolete scrap recycled into commercial steelmaking in the years 1997-1999 was about 42 million metric tons per year. During the same period, U.S. produc- tion was about 98 million metric tons per year. The amount of nonactivated, steel SRSM arising from decommissioning the population of U.S. power reactors, as shown in Table 3-2, ranges from 0.74 million to 1.05 million metric tons (de- pending on the amount excluded as LLRW). Based on the distribution of current license expiration dates for U.S. power reactors over a 25-year period, the aver- age amount of steel SRSM would be between 30,000 and 42,000 metric tons per 2Presentation to the committee by Ray Turner, David I. Joseph Company, June 13, 2001, Wash- ington, D.C.
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS 61 year. If the larger quantity (42,000 metric tons per year) was recycled, the poten- tially radioactive scrap would constitute only about 0.1 percent of the total steel scrap recycled each year. This small amount of metallic SRSM indicates that the effect on the available scrap metal resources is negligible if the metal is not recycled. Nonpower Reactors There are 46 USNRC-licensed research reactors in the United States, of which 36 are still operational (SCA, 2001, Table 2-79~. Konzek et al. (1995) developed a decommissioning materials inventory for a reference research reac- tor that is presented again in SCA (2001~. Also given in SCA (2001) are decom- missioning data from four retired research reactors. The data from these four reactors were used in a least-squares analysis to develop a scaling factor for the weight of decommissioning material as a function of the licensed power rating of each research reactor relative to the reference research reactor (SCA, 2001, p. 2- 138~. The resulting equation for the scaling factor is Mi/MR = [Pi/PRji 08~3, where M is the weight of material and P is the power rating, for the ith reactor and the reference reactor, respectively. The R2 value for the fit of the data to the equation was 0.97. The power ratings for the four research reactors used in the analysis ranged from 5 W to 20 MW, and the power rating of the reference research reactor was just 1.1 MW. Because a certain amount of facility structure is needed almost regardless of the power rating of the contained reactor, this scaling factor may underestimate the quantities of materials arising from research reactors having the much lower power ratings. Computing this factor for each of the 46 licensed research reactors and summing over that population yields the population scaling factor (65.79~. Multiplying the weights of each category of materials (structural steel, concrete, system steel) from the reference research reactor by the popula- tion scaling factor yields the population weights for each material category from U.S. research reactors, as shown in Table 3-3. The weights of structural steel and concrete SRSM are assumed to all be clearable, without any exclusions for LLRW materials. The study committee also assumed that metallic SRSM from the sys- tem steel category would have the same 30 percent fraction that would have to be disposed of as LLRW as assumed in the previous section on power reactors. The inventory of steel and concrete from research reactors represents about 1.4 per- cent of the total weight of SRSM from the power reactors. INVENTORIES OF RADIOACTIVE WASTE FROM OTHER LICENSED AND UNLICENSED SOURCES Radioactive materials are generated in a number of industrial environments, where the sources range from dilute to concentrated and from small volumes to
62 THE DISPOSITION DILEMMA TABLE 3-3 Decommissioning Materials Inventory from the Population of U.S. Research Reactors (metric tons) Composite Reactor Structural Steel Concrete System Steel Activated 6.5 Nonclearable 11 2.0 SRSM 113 1,910 46.0 Excluded (30%) 13.8 Net SRSM 113 2,010 39.9 Population weight SRSM 7,400 125,000 2,100 NOTE: Values are rounded to three significant figures. Population scaling factor is 65.79. SOURCE: Data derived from SCA (2001). large volumes. The information presented here is intended to provide a broad view of the types and quantities of radioactive materials present in the United States. Some of these materials are under federal regulatory control, others are under the control of state agencies, and still others may not be under any regula- tory control. The inventories include radioactive materials generated by (1) fuel cycle and (2) non-fuel cycle facilities, both categories of which are licensed, permitted, and regulated by the USNRC and agreement states; (3) facilities sub- ject to the USNRC' s Site Decommissioning Management Plan (SDMP); (4) DOE facilities; (5) DoD facilities; (6) facilities regulated by the Environmental Protec- tion Agency (EPA Superfund sites) or state agencies; and (7) industries that produce NORM, NARM, or TENORM. Steel and concrete SRSM arise from decommissioning activities at fuel- cycle and non-fuel-cycle facilities. The SRSM generated at these sites will in- clude some or all of the following: . Surface-contaminated equipment and material (i.e., concrete), and · Materials that are not from controlled radioactive areas and may be desig- nated as clearable, depending upon the type of facility. In general, activated metals and concrete have been and will continue to be disposed at licensed LLRW disposal facilities. These activated materials are not considered candidates for clearance, except where the concentration of activation products is very minimal. The category of surface-contaminated equipment and material includes some materials that are unlikely to be clearable and some that might be clearable after application of an appropriate decontamination technol- ogy. The types and quantities of radioactive materials arising from decommis- sioning each type of facility are discussed briefly below.
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS USNRC-Licensed Fuel Cycle Facilities 63 There are basically four types of fuel cycle facilities licensed by the USNRC: uranium mills, uranium hexafluoride conversion plants, uranium oxide fuel fabri- cation plants, and ISFSIs. Uranium Mills The population of uranium mills consists of four conventional surface ore crushing and/or leaching facilities and up to seven (one is not yet operational) in situ leaching facilities. In the surface mills, the waste materials from decommis- sioning are generally disposed by adding them to the ore tailings piles. Little waste remains that would require disposal at an LLRW facility. The in situ leaching facilities produce some wastes for LLRW disposal, and some of their surface structures and equipment may be conditionally clearable. The contami- nants present are primarily natural uranium (235U and 238U and their daughter products). No data are readily available on the volumes and weights of material and equipment that will arise from decommissioning in situ leaching facilities. However, because of the simplicity of these facilities, the committee expects that the quantities will be small. Uranium Hexafluoride Conversion Plants Decommissioning of the two existing uranium hexafluoride conversion plants is expected to be completed ultimately. One is currently operating; the other has been undergoing decommissioning for the past eight years. Although these two plants use different chemical processes, the SCA (2001) report assumes that they are sufficiently similar that a scaling factor of 2 is appropriate for calculating the size of the population waste inventory. The anticipated contaminants are prima- rily natural uranium (235U and 238U and their daughter products), with concentra- tions in the range of 10 tolO,000 pCi/g. Table 3-4 gives the estimated weights of radioactive materials arising from decommissioning these facilities. For the un- cleared equipment, the study committee accepted the assumption made by Elder (1981) that 40 percent is LLRW and 60 percent is SRSM. For the non-LLRW concrete and structural steel (including reinforcing bar in concrete, or rebar), Elder (1981) assumed that 40 percent is SRSM and 60 percent is clearable. Because there are only two of these facilities, the quantities requiring disposition are small. Uranium Fuel Fabrication Facilities There are seven uranium fuel fabrication plants presently licensed in the United States. Their licenses are currently scheduled to expire 2001 to 2009. At
64 THE DISPOSITION DILEMMA TABLE 3-4 Decommissioning Materials Inventory from the Population of U.S. Uranium Hexafluoride Conversion Plants (metric ton) Materials Structural Steel Concrete Equipment LLRW 161 928 SRSM 616 3,250 1,390 Clearable 922 4,870 271 Total clearable 1,540 8,120 1,660 NOTE: Values are rounded to three significant figures. SOURCE: Data are derived from SCA (2001). least four of these plants will probably have their licenses extended, in order to serve the U.S. nuclear power industry and the nuclear navy. Thus, the material inventories arising from decommissioning the population of uranium fuel fabri- cation plants, shown in Table 3-5, are likely to be distributed over the next 30 years or more. The principal contaminants are low-enriched uranium (235U and 238U and their daughter products). The radioactivity levels on plant equipment could range from essentially zero up to 38,000 pCi/g. For the committee's analysis, only six of the seven plants were considered; the naval reactors fuel plant was omitted. Table 3-5 uses a committee-derived population scaling factor, developed using the formula in SCA (2001), for esti- mating the weights of materials in other plants from the weights in a reference fuel fabrication plant (Wilmington, North Carolina), for which data were given in SCA (2001~. For equipment, the same assumptions were used that were made for TABLE 3-5 Decommissioning Materials Inventory from the Population of U.S. Fuel Fabrication Plants (metric tons) Materials Structural Steel Concrete Equipment LLRW 347 2,010 SRSM 6,500 21,000 3,020 Clearable 9,750 31,500 4,400 Total clearable 16,300 52,500 7,420 NOTE: The committee used a scaling factor of 3.88 applied to the reference plant value. Values are rounded to three significant figures. SOURCE: Reference plant data are from SCA (2001).
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS 65 the uranium hexafluoride plants. Namely, of the uncleared material, 40 percent would be disposed as LLRW and 60 percent is SRSM. For concrete and structural steel (including rebar), 40 percent is assumed to be SRSM and 60 percent is assumed clearable. Independent Spent Fuel Storage Installations An independent spent fuel storage installation (ISFSI) is a facility in which spent nuclear fuel from a nuclear power reactor is stored, primarily fuel that is in excess of the capacity of the spent fuel pool at the reactor. There are 15 ISFSI facilities in service in the United States employing five design concepts: 1. Vertical ventilated concrete casks (four sites), 2. Horizontal storage modules (eight sites), 3. Vertical metal casks (one site), 4. Modular vault dry storage (one site), and 5. Water-filled pool (one site). Additional facilities are planned to be constructed in the coming decade to ac- commodate the excess spent fuel accumulating at reactors until a federal deep geologic repository begins receiving spent fuel for disposal. The interior surfaces of the metal storage canisters in the dry storage con- cepts will undoubtedly be contaminated and might actually be activated to very low activity levels. However, the quantities of SRSM are not large and would accumulate slowly. The accumulation rate will be determined by the rate at which the geologic repository receives spent fuel. Thus, the committee has concluded that these materials will not contribute significantly to the total quantity of mate- rials entering the disposal stream during any given year. Non-Fuel-Cycle Licensees of the USNRC or Agreement States There were roughly 21,000 radioactive materials licensees in the United States in 2000, consisting of roughly 5,000 USNRC licensees and nearly 16,000 agreement state licensees. Of the various types of licensees in this group, those involved in research and development, medical applications, nuclear pharmaceu- ticals, and the manufacture of sealed sources and radio-labeled compounds gen- erate materials potentially subject to a clearance regulation. The estimates for radioactively contaminated materials generated by these licensees were calcu- lated by multiplying the estimated weight of SRSM in a reference facility by the number of USNRC-licensed facilities of the same type. This result was then multiplied by 4 to account for the 75 percent of radioactive materials licenses issued by agreement states (SCA, 2001~.
66 Hospitals THE DISPOSITION DILEMMA SRSM in hospitals consists of floors, walls, equipment (metal), and cabinets (wood). The total U.S. inventory is approximately 436,000 metric tons, of which an estimated 8,720 to 21,800 metric tons is disposed annually. Most of these materials are clearable. However, some small percentage contains fixed 3H and 14C contamination that must be disposed of as biomedical LLRW. Research and Development Laboratories The inventory of possibly radioactive materials in the reference research and development laboratory was estimated in SCA (2001) to be about 1 metric ton of equipment and about 2.5 metric tons of concrete. Hot cells and fume hoods were not included in the estimates, since they are expected to contain too much con- tamination to be considered for clearance. The total U.S. inventory for research and development laboratories was estimated by SCA (2001) to be about 2,058 and 5,145 metric tons of equipment and concrete, respectively. Manufacturers of Sealed Sources and Radio-Labeled Compounds Manufacturers of sealed sources and radio-labeled compounds use licensed radioactive materials in hot cell laboratories. Potentially clearable materials con- sist of approximately 1.7 metric tons of metal, concrete, and asphalt tiles in the reference facility, or about 107 metric tons for the 63 such facilities in the United States (SCA, 2001). Biomedical Wastes Biomedical radioactive waste is generated under either USNRC or agree- ment state licenses by institutions engaging in medical, biological, or academic research and in universities and hospitals where radioactive materials are used for research, diagnosis, or treatment of disease. Biomedical use of radioactive mate- rials typically generates small volumes of LLRW with low content of radioactiv- ity. Although short-lived radionuclides are most often used in biomedical re- search, longer-lived radionuclides such as tritium and 14C are also used.3 The longer-lived wastes are disposed at licensed LLRW facilities after pretreatment to reduce waste volume, which reduces disposal costs. Much of the short-lived waste can be managed by storage for decay, with subsequent disposal according to the nonradioactive constituents of the wastes (NRC, 2001~. 3criteria in lo CFR Part 20 allow disposal of volume-contaminated animal tissue containing less than 1.85 ksqlg of 3H or 14c as if it were not radioactive.
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS Facilities Under the Site Decommissioning Management Plan 67 The USNRC is regulating the decommissioning of 28 facilities under the SDMP. Radioactive residues at these facilities consist primarily of ore or slag containing elevated concentrations of natural radioactivity (i.e., uranium and thorium and their daughter products). Approximately 4,100 cubic meters (9,840 metric tons) of concrete SRSM is expected to be produced. About 84,000 cubic meters of slag from previous processes may be recovered for reprocessing or other controlled uses. DOE Facilities Numerous DOE facilities have moved from production to decontamination and decommissioning. Assuming that 25 percent of the steel and iron present at these facilities cannot be recycled for economic or radiological reasons, recent studies estimate that about 1 million metric tons of metallic SRSM exist in current inventory or are expected to become available by 2035 (SCA, 2001~. An estimated 60 percent of these metals will come from decommissioning the gas- eous diffusion plants located at Oak Ridge, Tennessee (the K-25 plant); Piketon, Ohio ("Portsmouth"~; and Paducah, Kentucky. The radionuclides of concern at the gaseous diffusion plants include 235U,238U 239Pu 237Np and 99Tc Concen "rations tend to be dilute, with 78 percent of the ferrous metals estimated to contain less than 4,400 Bq/kg (120 pCi/g). (The significance of these concentra- tions depends on the scenarios whereby the radionuclides could expose humans to a radiation dose. This issue is covered in detail in Chapter 5.) As discussed in the section on decommissioning power reactors, the amount of steel scrap recycled into commercial steelmaking is currently about 42 million metric tons per year. The projected 1 million metric tons of steel SRSM generated from DOE decommissioning and cleanup operations are expected to become available over about a 25-year period, or an average of about 40,000 metric tons per year. Thus, if recycled, this amount of slightly contaminated scrap would constitute only an additional 0.1 percent of the annual stream of recycled obsolete steel. Available data are insufficient to characterize the inventory of concrete SRSM from the DOE complex. One DOE study (DOE, 1996) estimates that about 3.1 million cubic meters (~3.7 million metric tons) of rubble and debris will result from all decontamination and decommissioning operations through 2050. (Together with the estimate of steel SRSM given above, this data implies a mass ratio of concrete to metal of 3.7 to 1 an aggregate number that could vary widely by individual site and type of facility.) Another DOE study (DOE, 1999) has estimated the DOE concrete volume would be over 10 million cubic meters (greater than 12 million metric tons). These two estimates illustrate the kind of uncertainty that exists in the amount of potentially contaminated concrete present in the vast DOE complex.
68 THE DISPOSITION DILEMMA Much of the concrete will probably be used as on-site fill material, after in situ removal of isolated areas of contamination with an appropriate decontamina- tion technology. As shown in Table 3-6, the quantity of radioactively contami- nated soil that may arise during cleanup efforts at DOE facilities could be as large as 76 million cubic meters. DoD Facilities Many DoD facilities are licensed by the USNRC, including hospitals, labo- ratories, proving grounds, some nuclear reactors, weapons facilities, and missile launch sites. The DoD holds approximately 600 licenses and/or radioactive mate- rials permits, of which three-quarters are for sealed sources (and therefore gener- ate no radioactive waste). Most of these licenses cover a spectrum of operations similar to those found in the civilian world. As noted, the USNRC does not license naval reactors and associated propulsion units. Overall, about 115,000 cubic feet of LLRW is generated annually from DoD facilities. Most of this waste (greater than 90 percent) is from cleanup efforts rather than operations. TABLE 3-6 Sites Containing Radioactively Contaminated Soils Authority Location or Type No. of Sites Soil Volume (103 m3) DOE Fernald 1 2,100 Hanford 1 23,600 Idaho 1 720 Miamisburg 1 110 Nevada Test Site 1 16,000 Oak Ridge Reservation 1 133 Paducah 1 990 Portsmouth 1 25 Rocky Flats 1 460 Savannah River 1 19,000 Weldon Springs 1 480 Lawrence Livermore 2 2,212 National Laboratory Los Alamos National 1 9,900 Laboratory Sandia National 2 221 Laboratories USNRC or Nuclear fuel cycle (active 199 32 agreement states and inactive), including nuclear power plants Byproduct licensees 1,994 60 Other nonfederal Rare-earth mill sites 17 120 SOURCE: Wolbarst (1999).
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS EPA-Regulated Superfund Sites 69 For more than a half century, radioactive materials have been produced and used in weapons production, power generation, and industrial and medical appli- cations. Because these materials were frequently released into the environment, thousands of sites within the United States have become contaminated some slightly, some heavily. Furthermore, other industrial activities not focused on using radioactive materials have resulted in the concentration of significant amounts of NORM at various sites. As reported by the EPA (63 Federal Register 51982-51888; September 29, 1998), there are about 1,200 sites on the National Priorities List (NPL) of facilities needing cleanup, of which about 150 are federal facilities. According to one estimate, at least 75 sites on the NPL are radioac- tively contaminated (Wolbarst, 1999~. A current estimate by EPA places the number of sites on the NPL having radioactive contamination at approximately 60 (EPA, 2001~. Although DoD and DOE are responsible for the majority of these sites, more than 20 of them did not originate from federal agency activities. Table 3-6 illus- trates the approximate inventory of sites containing soils contaminated with ra- dioactivity, their locations, and the estimated volumes of contaminated soil asso- ciated with each site. NORM, NARM, and TENORM Several types of industrial activity coincidentally enhance the concentration of NORM in waste residues, resulting in the generation of TENORM. The typical radionuclides of concern in TENORM are members of the thorium and uranium decay series. The type of processing performed on natural materials and the time expired since processing determine the equilibrium status of the radionuclides present. Industries associated with TENORM production may produce radioactively contaminated scrap metals, in addition to TENORM-containing waste residues. These industries include the following: Petroleum production, Uranium mining, Phosphate and phosphate fertilizer production, Fossil fuel combustion facilities (power plants), Drinking water treatment facilities, Metal mining and processing facilities, and Geothermal energy production facilities. Currently, there are no federal statutes explicitly regulating TENORM, al- though some waste streams fall under the jurisdiction of various EPA regulations
70 THE DISPOSITION DILEMMA or programs. Several agreement states regulate TENORM under their general rules governing possession of radioactive materials, and 11 states have promul- gated regulations specifically addressing TENORM. Table 3-7 lists estimates of TENORM wastes generated annually, with associated ranges of uranium, tho- rium, and radium concentrations. Waste management practices or clearance of TABLE 3-7 Sources, Quantities, and Concentrations of TENORM Concentrationa (Bq/kg) Metric Tons Waste Source per Year Uranium Thorium Radium Uranium overburden 3.8 x 104 1.8 x 103 990 920 Phosphate 5.0 x 104 Bkg-3.0 x 103 Bkg-1.8 x 103 400-3.7 x 106 Phosphogypsum 4.8 x 104 Bkg-500 Bkg-500 900-1.7 x 103 Slag 1.5 x 103 800-3.0 x 103 700-1.8 x 103 400-2.1 x 103 Scale 4.5 x 10° 1.1 x 10 3- 3.7 x 106 Phosphate fertilizers 4.8 x 103 740-2.2 x 103 37-180 180-740 Coal ash 6.1 x 104 100-600 30-300 100-1.2 x 103 Fly ash 4.4 x 104 Bottom ash 1.7 x 104 Petroleum production 2.6 x 102 bkg-3.7 x 106 Scale 2.5 x 1ol bkg-3.7 x 106 Sludge 2.3 x 102 bkg-3.7 x 103 Petroleum processing 210pb and 210 Refineries >4.0 x 103 Petrochemicals >4.0 x 103 Gas plants 210pb and 210 Water treatment 3.0 x 102 100-1.5 x 106 Sludge 2.6x 102 100-1.2x 103 Resins 4.0 x 1ol 300-1.5 x 106 Mineral processing 1.0 x 106 6-1.3 x 105 8-9.0 x 105 <200-1.3 x 105 Rare earths 2.1 x 1ol 2.6x 104- 9.0X 103 1.3 x 104- 1.3 x 105 9.0 x 105 1.3 x 105 Zr, Hf. Ti, Sn 4.7 x 102 6-3.2 x 103 8-6.6 x 105 300-1.8 x 104 Alumina 2.8 x 103 400-600 500-1.2 x 103 300-500 Cu and Fe 1.0 x 106 <400 <400 <200 Geothermal waste 5.4 x 1 ol 400- 1.6 x 104 Paper mills >3.7 x 103 Total 2.27 x 106 abkg = background radiation level. SOURCE: USNRC (2001a).
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS 71 materials from regulatory control depends on both the bulk quantity of the mate- rial involved and the concentrations of these key radionuclides in it. As shown in Table 3-7, the amount of TENORM that could fall under USNRC waste disposal regulations would be about 2.3 million metric tons per year, on a continuing basis. FINDINGS Finding 3.1. Licensees may seek to clear about 740,000 metric tons of metallic SRSM that arise from decommissioning the current population of U.S. power reactors during the period 2006 to 2030 (about 30,000 to 42,000 metric tons per year). About 8,500 metric tons per year are expected to arise from decommission- ing USNRC-licensed facilities other than power reactors during the same time period. The total quantity of metal from both power reactor and non-power reac- tor licensees, up to approximately 50,000 metric tons per year, represents about 0.1 percent of the total obsolete steel scrap that might be recycled during that same 25-year period. Finding 3.2. If most of the licensees of currently operating reactors obtain 20- year license extensions, relatively little SRSM will arise from power plant de- commissioning during the 2006-2030 period. Finding 3.3. Because of the difficulty of determining the quantities and levels of contamination that have penetrated into the concrete, concrete SRSM is generally considered to be volume contaminated. Concrete SRSM constitutes more than 90 percent of the total SRSM arising from decommissioning the population of U.S. power reactors. Finding 3.4. About 1 million metric tons of metallic SRSM and anywhere from about 3.7 million metric tons to greater than 12 million metric tons of concrete SRSM are projected to arise from cleanup and decommissioning of DOE facili- ties during the coming 25 years. This quantity of metallic SRSM is comparable in magnitude to the quantity of metallic SRSM estimated to arise from decommis- sioning the population of U.S. power reactors and corresponds to only an addi- tional 0.1 percent of the total obsolete steel scrap recycled in the United States during the same 25-year period. Finding 3.5. TENORM is generated in the United States at an annual rate of about 2.3 million metric tons per year. The quantity of TENORM SRSM pre- dicted to arise over the coming 25-year period is nearly 16 times larger than the quantity of SRSM estimated to arise from decommissioning the population of U.S. power reactors.