1

Context and Setting

The nation’s biggest and most complex nuclear cleanup challenge is at the Hanford Nuclear Reservation, which has its origins in plutonium production, starting in 1943, during the Manhattan Project. By 1987, when the last and ninth plutonium production reactor was shut down, the Hanford Nuclear Reservation had produced about two-thirds—approximately 67 metric tons—of the nation’s plutonium stockpile for nuclear weapons. The massive scale of the production processes resulted in significant amounts of radioactive and other hazardous wastes as well as substantial amounts of airborne, surface, subsurface, and groundwater contamination. Presently, 177 underground tanks collectively contain about 211 million liters (about 56 million gallons) of waste (WRPS, 2018). The chemically complex and diverse waste is difficult to manage and dispose of safely because of several factors. These include the use of a variety of methods for plutonium extraction from irradiated nuclear fuel, the mixing of wastes among tanks from transfers to optimize tank usage, the prior efforts to neutralize or otherwise alter the waste, the recovery of cesium-137 and strontium-90, and the addition of materials to the tanks from auxiliary processes (Peterson et al., 2018). The U.S. Department of Energy’s Office of Environmental Management (DOE-EM) is responsible for managing and cleaning up the waste and contamination under a legally binding Tri-Party Agreement (TPA) with the Washington State Department of Ecology and the U.S. Environmental Protection Agency.

In the committee’s first review report, the emphasis in the introductory chapter was on the congressional mandate in Section 3134 of the National Defense Authorization Act of Fiscal Year 2017 (Sec. 3134) (see Appendix A). The committee continues to underscore the fundamental importance of this mandate, and thus, this chapter also provides a brief introduction about the study’s mandate to set the stage for this review.

PROPOSED TREATMENT PLAN AND CONGRESSIONAL MANDATE TO ANALYZE AND REVIEW THE ANALYSIS OF SUPPLEMENTAL TREATMENT APPROACHES

The salient points for understanding the proposed treatment plan and the congressional mandate are the following. DOE-EM has proposed to retrieve the waste from the tanks to produce two waste streams, high-level waste (HLW) and low-activity waste (LAW), by removing several specific radionuclides that contain most of the radioactivity from the liquids and dissolved salt cake in the tanks to yield liquid LAW and then combining the removed radionuclides with the HLW solids. DOE-EM estimates that the HLW will contain more than 90 percent of the radioactivity and less than 10 percent of the total volume, while the LAW will consist of less than 10 percent of the radioactivity and more than 90 percent of the volume.

To treat these two waste streams, the plan is to use vitrification, or immobilization in glass waste forms, for all of the HLW stream and for at least one-third and perhaps all of the LAW stream (depending on analysis yet to be completed and decisions yet to be made). Due to capacity limits in the LAW vitrification facility portion of the Waste Treatment and Immobilization Plant (WTP), which is under construction, DOE-EM anticipates that there will be substantial amounts of low-activity waste that the WTP cannot process. The WTP’s design would allow for at least one-third and perhaps about one-half of the LAW to be vitrified. To increase LAW treatment capacity, DOE-EM intends to decide on a supplemental treatment approach and build another treatment facility to implement it. The supplemental low-activity waste (SLAW) to be treated would be similar in composition to the LAW to be treated in the WTP. The LAW—whether from the WTP or the SLAW facility—is intended to be disposed in near-surface facilities, which

can include the Integrated Disposal Facility (IDF) at Hanford, or off-site such as at the Waste Control Specialists (WCS) facility near Andrews, Texas.

DOE-EM has yet to select a supplemental treatment approach. To help with that selection, Congress has directed DOE-EM in Sec. 3134 to contract with a Federally Funded Research and Development Center (FFRDC) to perform analysis on treatment approaches. According to Sec. 3134, the treatment approaches considered should at a minimum include:

1. Vitrification, to produce glass waste forms, either using Joule-heated melters, which are to be used in the WTP, or bulk vitrification;
2. Grouting, to produce cementitious waste forms; or
3. Fluidized-bed steam reforming (FBSR), which can produce a calcined powder or a monolithic crystalline ceramic waste form.

Sec. 3134 also asks for identification by DOE of additional alternative approaches, if appropriate. At this stage of the study, neither DOE nor the FFRDC has identified additional primary alternative approaches. As discussed in the FFRDC’s draft report, dated July 15, 2018, there are nine variants of these primary three alternatives being considered. Also, to implement the three currently identified approaches, additional waste conditioning (pre-treatment) might be needed, for example, to remove certain radionuclides, or adjust the composition of the waste to make it more suitable or less costly for treatment and disposal.

In parallel to selecting the FFRDC, DOE was directed to contract with the National Academies of Sciences, Engineering, and Medicine (the National Academies) to conduct a concurrent, iterative review of the FFRDC report as it develops in order for the review results to inform and improve the FFRDC’s work.¹ DOE contracted with Savannah River National Laboratory (SRNL), an FFRDC, and then SRNL formed a team of experts from SRNL and other national laboratories. The charge to the FFRDC team from Sec. 3134 is in Appendix A. The Statement of Task is in Appendix B.

STUDY PROCESS

In this second review, the committee discusses its observations and provides its peer review of the FFRDC’s draft report, dated July 15, 2018,² and the FFRDC’s presentations at the public meeting in Richland, Washington, on July 23-24, 2018.³Table 1-1 lists the FFRDC’s presentations from this meeting. The webcast videos of the three public meetings are archived and available for viewing.⁴

During the three public meetings, the committee received briefings from several presenters not from the team, as listed in Appendix D. In addition, the National Academies has received comments submitted via e-mail and mail, which are available in the Public Access File. Sec. 3134 specifies that “the National Academies of Sciences, Engineering, and Medicine shall provide an opportunity for public comment, with sufficient notice, to inform and improve the quality of the review.” Also, Sec. 3134 highlights the necessity of consultation with the State of Washington and an opportunity for it to comment on the FFRDC’s draft report and the committee’s review of that report. The committee received invited presentations during the

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¹ For clarity, to the extent possible, this review report uses the nomenclature of the team for the FFRDC’s investigators, the committee for the National Academies committee, the draft report for the FFRDC team’s work, and the review or review report for the committee’s work.

² To access the FFRDC’s draft report, see http://dels.nas.edu/resources/static-assets/nrsb/miscellaneous/hanfordanalysis.pdf.

³ For this (the third) public meeting’s presentations, see http://dels.nas.edu/Past-Events/Meeting-SupplementalTreatment/DELS-NRSB-17-02/9944.

⁴ For the first public meeting’s video recording, see https://livestream.com/NASEM/DELS-NRSB; for the second public meeting’s video recording, see http://www.tvworldwide.com/events/nas/180228; for the third public meeting’s video recording, see http://www.tvworldwide.com/events/nas/180723.

second and third public meetings from the Washington State Department of Ecology and has considered these presentations in its review.

Table 1-2 shows the current schedule for the FFRDC’s work, the committee’s review, the public meetings, and the briefings to stakeholders. While this schedule is subject to change, it is designed to allow adequate time for the FFRDC and the committee to do their work in the iterative fashion described in the Statement of Task, and for regulators, stakeholders, and the public to provide comments. The next public meeting in Richland, Washington, is scheduled for November 29-30, 2018.

TABLE 1-1 List of the FFRDC’s Presentations, given on July 23-24, 2018, in Richland, Washington

TABLE 1-2 Planned Schedule of Forthcoming Public Meetings, FFRDC Reports, and Committee Reviews

To perform the peer review task, the National Academies formed a committee composed of 13 experts whose expertise spans the issues relevant for reviewing the FFRDC’s analysis, including risk assessments, cost estimation, cost-benefit analysis, waste processing, supplemental treatment approaches, legal and regulatory requirements, and large scale nuclear construction projects. A majority of the committee members have prior experience in studying cleanup activities at the Hanford Nuclear Reservation, as well as other DOE-EM sites. Appendix E contains biographical information about the committee members’ qualifications and experiences. The committee also has found it necessary to perform additional fact finding, for example, by receiving briefings from experts outside the FFRDC team about aspects of the supplemental conditioning, treatment, or analysis approaches. Any information learned by the committee during additional fact-finding will be made available in the study’s Public Access File.

THE HANFORD REGION’S ENVIRONMENT AND THE TRIBAL NATIONS

Knowing the vital role of the Columbia River and the surrounding environment is essential to understanding the Hanford Nuclear Reservation. The Columbia River is the fourth largest river in the United States by flow volume and has its headwaters in Canada. After making a journey of more than 1,200 miles, its waters flow into the Pacific Ocean at the border between the states of Washington and Oregon. A free-flowing section of the Columbia River, the Hanford Reach, forms the northern boundary of the Hanford Nuclear Reservation.

The availability of electricity from the Grand Coulee Dam on the Columbia River was a major factor in choosing the Hanford Site during the Manhattan Project. Equally important, water from the Columbia River was necessary to cool the plutonium production reactors. In the absence of the Columbia River, the Hanford Site would not have been given the mission to produce plutonium for nuclear weapons. The waste cleanup legacy from this mission affects the quality of Columbia River water and the surrounding environment.

Today, stakeholders and other members of the public speak, at times passionately, to the importance of the Columbia River for the well-being of those who live in the region. Indicative of the strength of this public sentiment, this review notes some particular comments received during the information-gathering sessions⁵:

• The river is the economic and ecological heart of the region, and the ancestral and modern-day home to tribes.
• This river’s importance to our state, our region, and our identity is not debatable.
• The Columbia River must be protected.

For thousands of years, several tribes have lived by the Columbia River; these tribal nations include the Yakama, the Umatilla, the Nez Pierce, and the Wanapum. Members of these tribes are among today’s stakeholders. Their comments have informed both this review report and the previous review report.

In 1943, the U.S. Army arrived at the site that was to become the Hanford Nuclear Reservation. The Army’s task was to clear the land of inhabitants and begin construction of the facilities needed to produce plutonium. In addition to ranchers and farmers who had more recently settled on the land, members of the Wanapum were still in the area, and they fished and gathered food along the Columbia River. Along with the ranchers and farmers, in 1943 the Wanapum were forced to abandon their lands along the river so that construction at the Hanford Site could begin.

This committee’s first report (hereafter referred to as Review #1) published June 8, 2018, included comments from Matthew Johnson, a representative of the Confederated Tribes of the Umatilla Indian Reservation. Although he reported that his tribe had ceded to the United States 6.4 million acres in the Treaty of 1855, the tribe has retained certain rights to hunt, gather, and pasture animals and to fish at usual and accustomed places, which include parts of the Hanford Nuclear Reservation.

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⁵ These comments and those below have been paraphrased from the stakeholders’ presentations. To view the videos of these presentations, see http://www.tvworldwide.com/events/nas/180723/.

He further noted:

• Tribal health and culture is based on the ability to access and safely use traditional foods, known as First Foods.
• We are a food-based culture and need safe access to those foods.
• We want the natural and cultural resources to be protected, restored, clean, and safe to use.

He also emphasized that members of his tribe do not view Hanford with the same time perspective as do many others, stating, “We have been here for 10,000 years.”

This review report adds the voice of Alfrieda Peters, a representative of the Yakama Nation, who also spoke of the tribal and personal connections to the Columbia River and of the importance she gave to the land surrounding it:

• Since time immemorial, our ancestors fished, hunted, and gathered food on this land.
• The Yakamas are inseparable from this land. This land and all its resources have been our homeland.
• We are here to express our opinion about leaving high-activity waste near the Columbia.
• We are opposed to DOE’s reclassifying of the high-level waste and want all wastes to be removed from the site.

THE WASTE TANKS AND THEIR CONDITION

In relatively close proximity to the Columbia River, the presence of radioactive waste is highly problematic to those living in the area today, as indicated by the Yakama Nation representative’s comments. As mentioned earlier, the cleanup challenge centers today and for the coming decades on the waste tanks. According to DOE-EM, DOE’s Office of River Protection (DOE-ORP) is charged with the mission: “To safeguard the nuclear waste stored in Hanford’s 177 underground tanks, and to manage the waste safely and responsibly until it can be treated in the Waste Treatment and Immobilization Plant for final disposition” (DOE-EM, 2015). These tanks are aging, and many are operating well beyond their design life. More than sixty tanks may have already leaked more than 1 million gallons of waste into the ground, according to DOE’s estimates (GAO, 2017). As time passes, more tanks are likely to leak; however, mitigating this risk is that practically all of the liquids able to be pumped from the single-shell tanks have been removed and placed in the double-shell tanks. The tank degradation time clock is running, thus adding urgency to all of the information presented in this review and the overall tank remediation effort. Failure to retrieve, treat, and store waste from these tanks could eventually result in environmental, economic, and public health consequences to those living in the region. A failure also represents a broken TPA commitment to safely remove waste from the tanks in a timely manner.

As part of its fact-finding in July, the committee visited one of the tank farms and entered an above-ground mock-up of one of the tanks—part of the Cold Test Facility—to better appreciate the massive size of a tank and to learn about the technologies used to remove the waste contents. The presentations given by DOE-ORP and Washington River Protection Systems provided the following information concerning tank remediation:

• Several technologies have been used to retrieve waste out of several single-shell tanks, including a “sluicer” (nozzle jet) that sprays high-pressure liquid, including recycled waste, to create slurries that are pumped out of the tanks.
• All of the retrieved waste subsequently goes to an evaporator to reduce its volume by removing excess water. Next, this waste is added to a double-shell tank.
• The available capacity in the existing 28 double-shell tanks is not sufficient to hold all of the waste now contained in the 149 single-shell tanks, although the capacity of an individual double-shell

• tank is typically significantly bigger than a single-shell tank. As noted above, the liquids able to be pumped from the single-shell tanks have been placed into the double-shell tanks. Once the WTP is operational, it will take waste from the double-shell tanks to free up capacity in order to allow more retrieval from the single-shell tanks. Thus, waste retrieval from all of the single-shell tanks depends on an operational WTP, according to DOE-EM’s current treatment plan.

• To date, waste has been removed from 18 single-shell tanks, leaving no more than half of an inch of residual waste in each of these tank bottoms.
• DOE-ORP intends to back-fill the nearly empty tanks with grout that contains additives to retain any remaining radionuclides.

While maintaining the integrity of the tanks and retrieving waste from the tanks are important for managing risks, the committee notes what is not in the scope of the FFRDC’s analysis and the committee’s review, namely, tank waste management and retrieval, HLW processing and treatment, and the WTP’s design, construction, and operations. Nonetheless, decisions about how and when to treat the SLAW affect the overarching systemic risks, and as noted above, the SLAW will derive from processing the tank waste in the WTP pre-treatment facility.

VITRIFICATION, THE CONCEPT OF “AS GOOD AS GLASS” FOR OTHER WASTE FORMS, AND WASTE DISPOSAL OPTIONS

During the three public meetings, the committee heard strong views, especially from representatives of the Washington State Department of Ecology, in favor of using a vitrified waste form for SLAW. Because the selection of the SLAW treatment approach is central to this study, this section provides context for the Washington State Department of Ecology’s position. The committee notes that this section is not a detailed history, but interested readers can delve into the references in the Washington State Department of Ecology’s public presentations as well as the relevant sections of the 2011 National Research Council Consensus Study Report Waste Forms Technology and Performance (NRC, 2011).

The Washington State Department of Ecology has expressed two main concerns about waste forms other than glass: inferior waste form performance (specifically, degradation rates and the release rates of radionuclides and some chemicals) and increased waste volume. The increased waste volume concern is directed at grout waste forms, which would be about twice the volume of glass waste forms for the projected volume of low-activity waste to be treated, according to the Washington State Department of Ecology. Indeed, the FFRDC’s draft report (see Table F-14) posits that the volume for a grouted waste form would increase by a factor of 1.8. The Washington State Department of Ecology has told DOE that it has assessed that this increased volume “would create increased disposal needs and associated costs” (DOE, 2012).

As to waste form performance, the Washington State Department of Ecology has stated that any non-vitrified waste forms would have to be “as good as glass.” This regulatory agency has pointed to the definition of “as good as glass” given by Roy Schepens, then Site Manager at DOE-ORP, in a June 12, 2003, letter to Mike Wilson of the Washington State Department of Ecology:

The committee points out that it is not endorsing this view. The concept of “good as glass” is based on a history of discussions among DOE, the State of Washington, and others. There is undeniable ambiguity

and disagreement about DOE’s acceptance of the concept, to say nothing of its precise meaning. More importantly, the concept has not, to the committee’s knowledge, been adopted as a formal regulation or guidance by the federal government. While it is neither the FFRDC’s nor the committee’s role to define or urge adoption or rejection of a particular legal or regulatory standard, the FFRDC and committee would be remiss in ignoring the issue. “Good as glass” is fundamental to the interaction of DOE with the State of Washington, the Tribal Nations, and a large number of stakeholders. Agreement that such a concept—however defined—has been met would presumably go a long way to removing regulatory uncertainties and speeding implementation of a non-vitrification approach. On the other hand, the lack of agreement that a non-vitrification approach is “as good as glass” (again: however defined) will unquestionably increase uncertainty and may well extend the time to implementation. The committee cannot resolve the question—that is a matter for political and possibly judicial bodies—but the committee urges the FFRDC to elaborate the issues involved as a basis for the committee’s review in the next review report.

Data in DOE’s Final Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington, dated November 2012, appear to support the Washington State Department of Ecology’s position that the non-vitrified waste forms being considered for SLAW treatment are not “as good as glass” or have significant uncertainties as to whether they are “as good as glass.” For example, page S-75 of the Environmental Impact Statement states:

In addition, the Environmental Impact Statement, on page S-132, states that the radiological risk to a member of the public for steam-reformed LAW waste form is about an order of magnitude greater than a LAW glass waste form due to projected releases of the radionuclides technetium-99 and iodine-129 (DOE, 2012). The November 2012 Environmental Impact Statement is the most recently published document that the Washington State Department of Ecology has cited at the committee’s July 23, 2018, public meeting to support its position on “as good as glass,” though the document is capable of less prescriptive interpretations.

The current congressionally mandated study is an opportunity to bring new analysis to bear on the issue of “as good as glass.” In Review #1, the committee suggested “that the FFRDC’s analysis discuss what would be required for the non-vitrified waste forms being assessed to be considered ‘as good as glass’ in the context of the current state of technology for waste forms other than glass from a technical and human health risk perspective” (NASEM, 2018, p. 2). The FFRDC’s draft report, dated July 15, 2018, does not provide this analysis. The committee reiterates its previous suggestion that the FFRDC provide this analysis in its forthcoming report.

An essential related issue is which disposal facility or facilities would accept various waste forms. DOE has recently evaluated the IDF’s performance by assuming the LAW per se was vitrified and the secondary waste was in a grout waste form. (As of the writing of this review report in mid-September 2018, the performance assessment had not been released, but the committee received a briefing on aspects of this assessment at the second public meeting.) Notably, there has not been a performance assessment for the IDF that considers non-vitrified SLAW waste forms. The committee is not aware of plans for such a performance assessment. That being the case, any primary non-vitrified waste forms for SLAW would not be permitted in the IDF until a performance assessment including such waste forms was completed and waste acceptance criteria based on the assessment are established by DOE and the Washington State Department of Ecology.

If any selected off-site facility, e.g., WCS, declines to accept non-vitrified waste (assuming that this is chosen to treat the SLAW) from Hanford at any time during the decades of SLAW treatment, this treatment could come to a halt and that would also most likely affect the continued treatment of the HLW, which would likely have ripple effects throughout the cleanup mission at Hanford. The committee notes that the Washington State Department of Ecology’s presentation on July 23, 2018, mentioned that the need for SLAW could be overtaken by events, for example: “If DOE optimizes the operation of current facilities and glass loading.” Alternatively: “If DOE foregoes pretreatment and replaces it with Direct Feed HLW.” And finally: “If DOE considers off-site (out of state) disposal of LAW at Waste Control Specialists in Texas.” As a major party to the TPA and as the Washington State environmental regulatory agency, the Washington State Department of Ecology and the State officials to which it reports obviously have a key role, if not the key role, in determining whether to permit non-vitrified waste forms in the IDF.

For an expanded range of disposal options, the Washington State Department of Ecology and some stakeholders have expressed the view that DOE must show that the non-vitrified SLAW forms must meet the “as good as glass” performance concept. Without expressing a view on whether DOE is legally or otherwise obligated to make such a demonstration, the committee notes that this is a contested regulatory issue and has been for quite a long time; therefore, the committee restates its advice from Review #1 to the FFRDC to provide its technical analysis on durability, protectiveness, leachability, and other performance criteria for the non-vitrified waste forms.

Another major consideration and motivation for this study is the cost for various SLAW treatment approaches. As Jonathan Epstein, a professional staff member of the Senate Armed Services Committee, explained to the National Academies committee during the first public meeting in December 2017, a major rationale for the congressional mandate is to “fully inform” Congress, DOE, and other decision-makers about the costs for the various treatment technologies. In particular, he emphasized that a recent U.S. Government Accountability Office (GAO) report indicated significant cost savings for the grout treatment approach as compared to vitrification based on the experience of the Savannah River Site’s use of grout for about 4 million gallons of LAW (GAO, 2017). However, he pointed out that the chemical composition of the LAW at the Savannah River Site is not as complex as the LAW at Hanford, and this could affect the cost of using grout treatment at Hanford. He then underscored the importance of Sec. 3134 in ensuring that a credible analytic study is performed by the FFRDC to include a cost-benefit analysis for each treatment approach. Notably, the GAO report recommended:

In its report, GAO noted that “DOE agreed with both recommendations.”

REVIEW REPORT ORGANIZATION

The remainder of this review report is structured as follows:

• Chapter 2 provides the committee’s basic description of the draft report and its organization, identification of self-evident gaps, and discussion of the importance of and the need for a comparative analysis, including a cost-benefit analysis.
• Chapter 3 is the centerpiece of this review report in that it examines whether and how the FFRDC’s draft report analyzes the four critical issues for decision-makers and other stakeholders of (1) the safety of an alternative approach following waste disposal and the risks of the treatment technology, (2) confidence in whether each waste form production technology will work, (3) costs of the waste formation processes and comparison to each other, and (4) whether the waste form will comply with applicable laws and regulations.

• Chapter 4 discusses four (at first glance peripheral, but actually integral) additional processes that need to be considered for all treatment technologies. These four processes are additional SLAW pre-treatment, off-gas treatment, secondary waste, and load (SLAW feed rate) leveling and waste blending.
• Chapter 5 examines the FFRDC’s use of the analytic hierarchy process for its expert elicitation, which appears to be the FFRDC’s intended approach for a comparative analysis of the alternatives, and examines what is needed for a comparative analysis that will be helpful for decision-makers.