Appendix B
Management Strategies for Remediation of High-Level Waste at the Hanford Site
In 1972, the U. S. Atomic Energy Commission (USAEC) [a predecessor agency of the Department of Energy (DOE)] issued a report (U.S. Atomic Energy Commission, 1972) defining policies, criteria, and strategies for the management of Hanford high-level tank waste. Most of the heat-producing fission products (strontium-90 and cesium-137) were to be removed, solidified, encapsulated, and stored in cooling basins. The remaining liquids were to be evaporated to saltcake for interim storage. Three alternatives under consideration for the long-term storage of the Hanford high-level tank waste in a suitable chemical and physical form were (1) on site storage in near-surface engineered facilities, (2) on site storage in caverns mined in the deep basalt underlying the Hanford site, and (3) off site disposal in a federal repository. Studies and evaluations were underway at that time to provide the information and data necessary to make the needed decisions. This plan was never implemented, but the studies formed the starting point for subsequent disposal evaluations.
In 1977, the Energy Research and Development Administration (another predecessor agency, following the USAEC, of DOE) issued an evaluation of 27 alternative plans (U.S. Energy Research and Development Administration, 1977) for the processing and disposal of Hanford high-level tank waste. These 27 alternatives were further studied and developed, and the environmental aspects of four of the alternatives were issued in 1980 (Rockwell Hanford Operations, 1980). Still further studies and evaluations led to the issuance of the Hanford Defense Waste Environmental Impact Statement in 1987 (U.S. Department of Energy, 1987) and its associated 1988 Record of Decision (U.S. Department of Energy, 1988a). The Record of Decision converted to policy and into implementation the results of the many previous engineering studies relating to the disposal of Hanford tank waste.
The implementation strategy for the 1988 Record of Decision called for a phased approach for the processing of only double-shell tank waste for disposal. Single-shell tank waste was to be the subject of further studies and a subsequent environmental impact statement. Initially, the supernatant that qualified as low-level waste would be recovered and made into grout for on-site near-surface disposal. This was to be followed by retrieval of sludge, which would be washed using water to separate soluble solids. These solids would be pretreated to provide a low-activity liquid waste stream that could also be made into grout and disposed on site in near-surface vaults. These two separation approaches had been used during the prior cesium and strontium removal campaigns to free up much needed double-shell tank space for ongoing plutonium separations processing and to demonstrate early disposal of tank waste in a grout form. According to the 1988 Record of Decision, further separations of the low-activity
portion from the high-level portion of the remaining sludge were to be undertaken at a later date as more advanced separations technology became available. The objective of this phased approach was to start disposing of tank waste as soon as possible while minimizing the volume of HLW to be vitrified and sent to a geologic repository.
The advanced separations technologies were to be developed in the laboratory and subsequently tested on a pilot scale in B Plant (one of the three original chemical separations facilities in the Hanford Site 200 Areas, built in 1944). Upon successful demonstration on a pilot-scale basis, full-scale production capability would be installed in the B Plant canyon for the processing of the remaining double-shell tank waste.
Design of the Hanford low-level grout facility and the Hanford Waste Vitrification Plant was initiated in the late 1980s. Construction of the grout facility was completed in 1987 and 500,000 gallons (2,000 m3) of low-level supernatant were processed into grout in 1988.
In 1986, DOE agreed that all mixed waste (i.e., those wastes containing both radioactive and hazardous chemicals) at its sites were subject to the provisions of the Resource Conservation and Recovery Act of 1976 (RCRA). In 1987, officials of Region 10 of the U.S. Environmental Protection Agency delegated regulatory authority for all mixed waste at the Hanford Site to the Washington State Department of Ecology. The Hanford tank wastes are deemed to contain hazardous substances under RCRA provisions and, as a consequence of the new regulations, the tank wastes also become subject to State of Washington regulation.
In February 1988 negotiations were initiated among the DOE, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology on a compliance agreement for cleanup of the Hanford Site. In May 1989, the three parties signed the Hanford Federal Facility Agreement and Consent Order (also called the Tri-Party Agreement, or TPA) (Washington State Department of Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy, 1996 - current amendment) which established milestones enforceable by law for specific cleanup actions. The strategy for cleanup of tank waste incorporated in the TPA was that implemented for the 1988 Record of Decision (U.S. Department of Energy, 1988a).
Several safety issues concerning day-to-day operations were identified in early 1990. These safety issues were deemed to pose unacceptable risks for continued operations without corrective actions. Originally, 54 tanks (48 single-shell tanks and 6 double-shell tanks) were identified as having potential for release of highly radioactive material in the event of an uncontrolled temperature or pressure excursion. These 54 tanks were designated as Watch List Tanks in response to Public Law 101-510, Section 3137, ''Safety Measures for Waste Tanks at Hanford Nuclear Reservation," of the National Defense Authorization Act for Fiscal 1991. Sixteen tanks have subsequently been removed from the Watch List.
The immediate concern for resolution of the safety issues resulted in major changes in programmatic needs that preempted the previously established disposal program strategy promulgated by the 1988 Record of Decision and the 1989 TPA. The redirection of technical and financial resources to resolve or mitigate the safety issues and the imposition of operating restrictions caused slippage in the schedules of activities supporting the disposal program outlined in the TPA. Additionally, tank safety issue resolution was expected to require double-shell tank space that was dedicated to supporting the disposal program. In some cases, the Hanford baseline schedules could not be recovered, and, consequently, the 1989 TPA provisions regarding tank waste could not be met.
Following the issuance of the 1988 Record of Decision and the 1989 TPA, knowledge of conditions of the single-shell tank waste evolved considerably, resulting in some changes in thinking that previously had favored in situ disposal. Also, RCRA and the Nuclear Waste Policy Act of 1982, as amended, requirements ran counter to the in situ disposal approach. As a result,
in December 1991 DOE made a decision that retrieval of all single-shell tank waste would be used in subsequent tank waste remediation program planning. This meant a four-fold increase in the amount of tank waste to be processed, much more than could be handled by the planned vitrification and grout facilities.
Also, in this same time period B Plant was determined to be unacceptable as a pretreatment facility because it did not comply with current environmental regulations. Upgrades to reach compliance were not cost effective. A decision was made not to use B Plant for radionuclide separations processing, a decision that increased the cost and time duration for the disposal program.
Another issue developed when concerns about the performance of grout over the long term (i.e., leachability) were identified. This concern seriously challenged the acceptability of grout as a waste disposal form for low-level waste, even though it was being used at the Savannah River Site. In addition, other factors such as high radionuclide content, lack of retrievability, and the large number of vaults required raised further questions about the merit of grout as a low-level waste form.
To accommodate these major programmatic changes and impacts, in December 1991 the Secretary of Energy directed that an integrated single-shell and double-shell Tank Waste Remediation System (TWRS) program be established to plan and implement the disposal of all Hanford tank waste. A systems engineering approach was used to identify requirements, develop a program architecture, and study various disposal alternatives. By March 1993, DOE proposed a rebaselined TWRS program to the other two parties of the Tri-Party Agreement. The three parties immediately commenced negotiations on an amendment to the TPA.
Central to the DOE proposed program was the issue of dealing with the four-fold increase in waste volume resulting from the need to retrieve and dispose of all the single-shell tank waste. As noted previously, the capacity of the vitrification plant under design at that time was inadequate for the mission. Either a reduction of HLW volume using extensive separations technology or an increase in capacity of the vitrification facility, or a combination of both, would be required to process all the HLW in a reasonable time. The DOE proposed the cessation of design on the vitrification facility until extensive separations technology and a large-capacity melter could be developed. When this development work was completed, the proper sizing for the facilities would be established, and a definitive disposal strategy would be issued.
Another negotiation issue of major significance was the acceptance of grout as a low-activity waste (LAW) form. The disposal strategy presented by DOE for renegotiation of the 1988 TPA included development of separations technology that would reduce environmental risk from near-surface disposal by removing more of the radionuclides and hazardous chemicals of concern. During six months of negotiations among the three parties, input was sought from several stakeholders groups (e.g., regulators, special interest groups, the public at large, local governmental agencies, Native Americans). Two major benefits resulted from this public involvement effort and changed the proposed March 1993 strategy.
First, there was considerable opposition on the part of the stakeholders to the use of grout as a LAW form. This opposition stemmed primarily from concerns about the long-term performance of grout regardless of the radionuclide content and from the large amount of site acreage required for near-surface vaults. There was considerable interest in using vitrification as the technology for immobilizing LAW. As a result, the use of grout was abandoned and glass was adopted as the preferred form for LAW.
Second, because of the great uncertainty surrounding the construction of a federal repository to receive the immobilized HLW, the concept of minimizing glass volume was viewed by the stakeholders as less important than getting on with the task of cleanup. As a result, it was believed that sufficient HLW glass volume reduction could be obtained by enhanced
sludge washing, and large-capacity melters could process the expected volume of LAW in a reasonable time period. Although both enhanced sludge washing and large-capacity melters required development, it was believed this was a lower risk than the extensive separations technology and would result in an earlier commencement of disposal operations (J. Roecker, personal communication, 1998). If new cost-effective advanced separations technology were to become available at a later date, it would be incorporated to enhance the overall process.
The negotiations were completed by September 1993 and a revised TPA change package was issued for public review and comment. On January 25, 1994, Amendment 4 to the Hanford Federal Facility Agreement and Consent Order was signed, defining a new technical strategy for the disposal of Hanford tank waste. Although Amendment 4 defined a new technical strategy, many of the technologies to be employed were identical to those contemplated in the original TPA issued in 1989. The TPA Amendment 4 planning base envisioned immediate implementation of the full disposal program by the on-site Management and Operations contractor.
In the early 1990s the idea of reinventing government was introduced by the federal government. This idea was in turn conceptualized by DOE to mean that new and innovative approaches would be undertaken to accomplish normal government functions. The Secretary of Energy determined that privatization of some of DOE's waste site cleanup and environmental remediation would result in new and innovative approaches to accomplishing government functions. Privatization was defined by DOE as including the following:
- divestiture of functions,
- contracting out, and
- asset transfers.
A report defining DOE's approach to privatizing government functions was issued by the Privatization Working Group in January 1997 (U.S. Department of Energy, 1997a).
As a result, almost immediately upon issuance of Amendment 4 of the TPA, DOE began changing its disposal strategy planning to incorporate a phased implementation approach using commercial contractors competing on a fixed price basis; this was commonly know as the TWRS Privatization Initiative. With this approach the disposal of Hanford tank waste would be divided into two phases (U.S. Department of Energy, 1997b). During Phase I approximately 10 to 15 percent of the waste volume would be processed by two commercial firms on a fixed price basis. Phase I was further subdivided into 'A' and 'B' phases, Phase IA being a conceptual design phase leading to establishment of firm fixed prices for processing waste during Phase IB. The contractors would be paid a firm fixed price for deliverables at the end of Phase IA and for the delivery of immobilized waste during Phase IB. Upon successful completion of Phase I, each of the competing contractors would be invited to submit proposals for Phase II. One or two contractors could potentially be selected for Phase II processing.
On January 28, 1994, in a Notice of Intent published in the Federal Register (59 FR 4052), DOE announced its intent to prepare two environmental impact statements; (1) an interim action statement to resolve urgent tank safety issues, and (2) a TWRS statement addressing the long-term disposition of Hanford tank waste. The interim action Final Environmental Impact Statement was issued in October 1995, along with its corresponding Record of Decision (60 FR 61687) in November 1995. The TWRS Final Environmental Impact Statement (U.S. Department of Energy and Washington State Department of Ecology, 1996) addressing long term disposal of Hanford tank waste was issued in August 1996. The related Record of Decision (62 FR 8693) was issued in February 1997 (U.S. Department of Energy, 1997b).
In the 1997 Record of Decision DOE decided to implement the Phased Implementation alternative (the Preferred Alternative) for the management and disposition of the Hanford tank waste. Under the Phased Implementation alternative, the tank waste would continue to be stored in existing single- and double-shell tanks until the waste is retrieved for treatment, immobilization, and disposal. Initially a small quantity of waste would be treated and immobilized by implementing a demonstration phase (Phase I) to verify that the processes will function effectively and that the operations can be carried out in a cost effective manner using a privatized contract approach. Following successful completion of the demonstration phase, a full-scale production phase (Phase II) would be implemented. During both Phases I and II continued operation of the tank farm system and actions to address safety and regulatory compliance issues would be performed. The DOE would also continue to characterize the tank waste and perform technology development activities to reduce uncertainties and evaluate emerging technologies.
A TPA modification defining milestones implementing the phased TWRS Privatization Initiative was issued by DOE in December 1995, and was approved July 24, 1996. In February 1996 DOE issued a request for proposals (U.S. Department of Energy, 1996b) for the TWRS Privatization Initiative. Proposals were received in May 1996 (Briggs, 1996) and contracts with two commercial firms were signed in September 1996. Work has been completed on Phase IA deliverables and the results were delivered to DOE in January 1998.
In the DOE privatization approach, cleanup and environmental remediation facilities are developed, financed, constructed, owned, operated, and deactivated by the contractor(s). The technology development for those processing functions that fall under the privatization contractors is generally the responsibility of the contractors. In the privatization case, the technology development requirements for DOE are generally limited to those actions required of DOE to provide waste characterization data and waste delivery to the contractors, and to develop basic information for preparation of subsequent contract negotiations.
References
Briggs, W. 1996 (May 14). DOE Reviewing 2 Bids to Treat Tank Waste. Tri-City Herald, Kennewick, WA.
Rockwell Hanford Operations. 1980. Technical Status Report on Environmental Aspects of Long-Term Management of High-Level Defense Waste at the Hanford Site. RHO-LD139, Richland, WA.
U.S. Atomic Energy Commission. 1972. Plan for Management of AEC-Generated Radioactive Waste. WASH-1202, Washington, D.C.
U.S. Department of Energy. 1987 (December). Final Environmental Impact Statement: Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes General Summary, Hanford Site, Richland, WA. Assistant Secretary for Defense Programs DOE/EIS-0113, Washington, D.C.
U.S. Department of Energy. 1988a. Final Environmental Impact Statement for the Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes: Record of Decision. Federal Register 53(72):12499-12453, Washington, D.C.
U.S. Department of Energy. 1996b (February). TWRS Privatization Request for Proposals. Contract No. DE-RP06-96RL13308, Richland, WA.
U.S. Department of Energy. 1997a. (January). Harnessing the Market: The Opportunities and Challenges of Privatization; Report to the Secretary. Privatization Working Group, Washington, D.C.
U.S. Department of Energy. 1997b (February 26). Record of Decision for the Tank Waste Remediation System, Hanford Site, Richland, Washington. Federal Register 62(38):8693-8704, Washington, D.C.
U.S. Department of Energy and Washington State Department of Ecology. 1996 (August). Tank Waste Remediation System, Hanford Site, Richland, Washington, Final Environmental Impact Statement. DOE/EIS-0189, 6 volumes, Richland, WA.
U.S. Energy Research and Development Administration. 1977. Alternatives for Long-Term Management of Defense High-Level Radioactive Waste. ERDA 77-44, Richland, WA.
Washington State Department of Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy. 1996. Hanford Federal Facility Agreement and Consent Order: May 1989--As Amended, September 1990, September 1991, August 1992, January 1994, and February 1996. Report 89-10 Rev. 4, Richland, WA.
