ML20128C132

Final TER Related to Topical Rept USE-61-002-P, High-Strength Asphalt Solidification Process for Low-Level Radwaste,For Boric Acid Concentrates

ML20128C132
Person / Time
Issue date:	01/31/1993
From:	NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:
Shared Package
ML20128C083	List: ML20128C080 ML20128C101 ML20128C132
References
REF-WM-102 NUDOCS 9302030323
Download: ML20128C132 (25)

Text

_____

$ N>

United States Nuclear Regulatory Commission  %

Office of Nuclear Material Safety and Safeguards %0 Washington, DC 20555 9, , ,

FINAL Technical Evaluation Report related to Topical Report USE-61-002-P High-Strength Asphalt Solidification Process for Low-Level Radioactive Wastes U.S. Ecology Inc.

Docket No. WM-102 For Boric Acid Concentrates Prepared by: Low-Level Waste Management Branch Division of Low-level Waste Management and Decomissioning January 1993 9302030323 930129

- PDR WASTE PDR -

WM-102

' The Final Technical Evaluation Report incorporates the information contained in the Interim Technical Evaluation Report issued in July 1991 and Su)plement No I to that report, dated January 1992. In addition. it reflects tae test data submitted by U.S Ecology by letter, dated July 17,.1992,- that was'iden-tified as necessary confirmatory.information. The changes to the previous

- bar.

documents issued by NRC on this topical report are identified by a marginal 11

0 ABSTRACT This final Technical Evaluation Report (TER) has been prepared by the Office I of Nuclear Material Safety and Safeguards, of the U.S. Nuclear Regulatory Com -

mission, for the U.S. Ecology (USE), Inc. Topical Report (TR), USE-61-002-P.

This USE TR addresses the low-level radioactive waste forms produced by the USE high strength asphalt-solidification process. This is a continuous flow process in which the waste passes from the waste batch tanks and the asphalt supply tank to an evaporator / mixer, under elevated temperatures, and into the steel drums for solidification by cooling. The resultant cylindrical waste forms are intended to be suitable for disposal in facilities that are designed, constructed, operated and closed in accordance with 10 CFR Part 61 requirements. The staff concludes that, within the limitations specified in this TER, there is reasonable assurance that the low-level waste forms of I boric-acid wastes produced by the USE high-strength asphalt-solidification process will meet the stability requirements of 10 CFR Part 61 for waste char-acteristics. The strengths developed with this distilled asphalt exceed those normally developed by oxidized asphalt. Limiting conditions for the accept- l ance of such waste forms for disposal at a specific low-level waste disposal facility may be specified by the regulating authority for that facility. Cer-tain waste forms proposed for treatment by this process, at the percentage waste loadings and conditions have been found to be not in compliance with the requirements of Part 61, presently. These waste streams, waste loadings, and waste form products are not addressed by the TER. Only the boric acid concen-trates are addressed. Additional testing of the present or new formulations will be necessary if NRC approval is to be sought for the solidification /

stabilization of the other waste streams.

l l

l l

l 111 J

W- A= %= A R4+&.mK+, Mr 14A.e-dia A.3 ,

l'-

r7..O

' j.- 9 &

.c'4:,",..

4 -

T

-: .L 4

V3

--h n

}

s i h

-+

b I

s3 I

'k

.e,

{

P

+

b i

' +

5

• w i

F A

v b

h

'., ?

)

1 h

a

-,i e

3

. y-. t 4- y

-r p e+sA'_, 6 a 4 . p q

CONTENTS Ent 1.0 INTR 00VCTION..................................................... I 1.1 Regulations.............................................. .. I 1.2 Topical Report (TR) Submittals........................... .. 2 1.3 USE'High Strength Asphalt Solidification Process............ 3 2.0 TOPICAL REPORT

SUMMARY

3.0 EVALVATION PROCE0VRE...............................

4-4 4.0 REGULATORY Evaluation............................................ ..............- 5 4.1 Waste Characteristics.................................

4.2 Waste Streams Considered....................................

5 5

4.3 Major Review Areas.................................... ..... .....- 6 4.4 Minimum Requirements [10 CFR 61.56(a)]...................... 7 4.4.1 Packaging........................................... . 7 4.4.2 Liquid waste.......................................

4.4.3 Free Liquid..........................................

7 7

4.4.4 Reactivity of Product...............................

7 4.4.5- Toxic-Gas Generation................................. 8 4.4.6 Pyrophoricity....................................... 8 4.4.7 Gaseous Wastes....................................... 8 4.4.8 Hazardous Wastes.............. . ...................... 8 4.5 Stability Requirements [10 CFR 61.56(b)) and BTP on Waste Form, Rev. 1, January 1991............................ 9 4.5.1 Structural Stabil i ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-

a. Baseline Compressive Strength.................... 10

b. Thermal -Cycl e Re s i s tance. . . . . . . . . . . . . . . . . . . . . . . . . 11

c. Radiation Resistance............................. 11

d. Biodegradation Resistance........................ 12

e. Leach Resistance................................. 12 f.

g.

Immersion Resistance............................. -13 Correlation Testing.............................. 13

h. Determination of Homogenei ty. . . . . . . . . . . . . . . . . . . . . 13'

i. Dimensional Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.5.2 Free Liquids......................................... 15 4.5.3 Void Spaces.......................................... 15-4.6 Waste and Moisture Content of Waste Form.................... 15 4.7 Process-Control Program (PCP) and Quality Control . . . . . . . . . . . 15 4.8 Re po r t i ng o f Mi s h a p s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 v

PJL91 5.0 REGULATORY POSIT!0N.............................................. 16 5.1 Limitations................................. 1............. 17 5.1.1 Withdrawn Waste Streams............................... 17 5.1.2 Boric Acid Concentrates............................... 17 5.1.3 Waste Containers......................................

17 5.1.4 Process Control....................................... 17 5.1.5 Disposal Backfill Restrictions........................

18 5.2 Summary..................................................... 18

6.0 REFERENCES

...................................................... 18 vi

- - - - - - - - - - - - - - - - - - - - - ~ ~ ~ ^^^~~~^ ^ ^

WM 102 FINAL TECHNICAL EVALVATION REPORT l FOR WASTE FORMS PRCDUCED BY THE U.S. ECOLOGY HIGH-STRENGTH ASPHALT SOLIDIFICATION PROCESS

1.0 INTRODUCTION

This report provides the evaluation results of the technical review of informa-tion and data submitted by U.S. Ecology, Incorporated (USE) in a topical report (TR) entitled, " Stability of Low level Radioactive Wastes Solidified with High-Strength Asphalt," Report No. USE 61002-P, Revision 0, June 19,1989. The evaluation also included the review of supplemental information the vendor provided in response to requests for additional information. This Final Tech-nical Evaluation Report (TER) is a detailed evaluation of the waste form-qualification test data provided by USE to substantiate that the high strength asphalt solidification process will produce a waste form that meets the regula-tory requirements of 10 CFR Part 61 with respect to stability for boric acid concentrates.

Once a topical report review has been completed and the associated product has been approved, the TR process allows a user to reference the report to demon-strate that the subject area the report addresses has been through the regula-tory review process and is acceptable to the staff. Thus, the TR process allows the use of a repeated process, action etc., at several facilities, after a single successful review has been completed, without the need for a unique review. However, in the case of TRs for waste forms, waste generators must take additional actions (e.g., plant-specific process control procedures) to demonstrate that all portions of Part 61 have been met.

1.1 Reaulations By Federal Register Notice dated December 27, 1982 (47 FR 57446), the United States Nuclear Regulatory Commi,sion (NRC) amended its regulations to provide specific requirements for licensing of facilities for the land disposal of low-level radioactive waste (LLW). The majority of these requirements are now con-tained in Part 61 to Title 10 of the Code of Federal Regulations (10 CFR Part

61) entitled " Licensing Requirements for Land Otsposal of Hadioactive Waste"

( Re f. 1) . Modifications, mostly of a procedural nature, have been made to other parts of the Commission's regulations, such as 10 CFR Part 20 (" Standards for Protection against Radiation"). These regulations are the culmination of a set of prescribed procedures for low level radioactive waste disposal that were proposed in the Federal Register on July 24, 1981.

The effective date for the implementation of 10 CFR 20.311, which requires waste generators to meet the waste classification and waste form requirements of 10 CFR Part 61, was December 27, 1983. As set forth in 10 CFR 61.55, Class B and Class C waste must meet structural stability requirements that are estab-lished under 10 CFR 61.56 (b). As noted in 10 CFR 61.56(b)(1), structural sta-bility could be provided by (a) processing (i.e., solidification ~of) the waste form, (b) by the waste itself (as with large activated steel components), or (c) by placing the waste in a container or structure which would then provide the required stability (i.e., a high integrity container (HIC)). To the extent practicable, Class B and C waste forms or containers should, according to I

l

i Section 61.7 of Part 61, maintain structural stability for 300 years, in May 1983, the NRC provided additional guidance by means of a Technical Position on  !

Waste form (Ref. 2) that describes test procedures and criteria that can be j used to demonstrate the required long term, 300 yeae, structural stability, i The most recent guidarce on waste forms is provided in Revision 1 to the Technical Position on Waste Form, which was issued in January 1991 (Ref. 3).

1.2 Tooical Reoort Submittals and Actions t By l# iter, dated July 13, 1989 (Ref. 4), USE submitted their TR for review, noting that the processes described therein generally involved chemical pre-treatment of the wastes and the use of special high strength asphalt to meet the stability requirements of Part 61. The submittal also requested that certain parts of the report be treated as proprietary information.

NRC responded t ne requert for considering certain material as proprietary by -

a letter dated July 27, 1989 (Ref. 5), that outlined the conditions under which the review would be conducted, regarding protection of the USE information.

The letter also assigned a docket number to the TR review, and by so doing, acknowledged the acceptance of the TR for a formal technical review.

The proposed review schedule for the TR was sent to t%E by a letter dated October 5, 1989 (Ref. 6). State of South Carolina comments on the TR dated September 20, 1989, were forwarded to USE by a letter dated October 27, 1989 (Ref 7). The review schedule originally defined in October 1989 was.subse- .

quently revised by information provided in a letter dated May 3,1990 (Ref. 8).

NRC discussed the preliminary results of the technical evaluation, with USE, during a meeting on August 2, 1990. The issues discussed at the meeting ,

stemmed ' rom the results of the review process completed up to that date, by Division of Low level Waste Management staff and members of Brookhaven National Laboratory (BNL) that were providing technical assistance to NRC. The meeting was summarized in an enclosure to a memorandum dated January 10, 1991 (Ref 9).

The results of the NRC first round review were contained in a letter to USE, dated September 18, 1990 (Ref. 10), as a request for additional information (RAI).

In preparation for the response to the RAI, USE requested a meeting with NRC.

A meeting was held in Rockville, Maryland, on November 6,1990 (Ref.11), where the issues identified in RAI-l were discussed, and the major items of concern were highlighted. USE's formal response was submitted by a letter dated Decem-ber 14, 1990 (Ref. 12), which provided a reply to the September 18, 1990, RAI sent by NRC. In addition, the letter enclosed a " Test Plan for Supplemental Waste For, Qualification Testing," that had been identified as necessary as:a result of the RAI and meetings with NRC staff. Also, the Process Control Pro-gram for the USE Volume Reduction and Solidification System was enclosed. USE provided some additional statistical information in a letter dated December 31',

1990 (Ref.13) related to RAI 7.14.

In a letter dated April 26,1991 (Ref.14), NRC informed USE that the test data contained in the application with the proposed waste loadings for the various waste streams did not demonstrate the capability of meeting the structural stability requirements of 10 CFR Part 61. It was proposed that a meeting to discuss the details be held at USE's convenierce. A meeting was subsequently 2

4 I held on May 8, 1991, at which time VSE aresented NRC with a proposal regarding ~

an interim approval. The meeting and t1e proposal were documented in a letter to USE dated, May 17, 1991 (Ref. 16). NRC indicated an Interim Technical ,

Evaluation Report would be issued with various restrictions and conditions.

The July 1991 Interim Technical Evaluation Report (ITER) was issued by a letter dated August 2, 1991 (Ref. 18).

In response to open issues in the ITER, USE submitted a revised Process Control Program (PLP) by a letter dated, September 10, 1991 and provided some addi-tional information on the solidification process (Ref.19). NRC responded by I approving the PCP for interim use with one comment in a letter dated September 16, 1991 (Ref. 20). A subsequent submittal by USE on September 23, 1991, addressed and closed the NRC comment or the interim PCP (Ref. 21).

Based on the additional information, NRC issued Supplement No.1, dated January 1992, to the ITER by a letter dated January 24, 1992 (Ref. 22).

The test plan to complete the necessary confirmatory tests was submitted by U.S. Ecology by a letter dated March 17, 1992, requesting NRC review of the test program dated March 4, 1992 (Ref. 23). NRC responded with a letter, dated April 16, 1992, indicating the test program as proposed was responsive to the issues defined in the ITER (Ref. 24).

USE submitted the results of the additional testing by a letter dated July 17, 1992 that enclosed the test report dated July 9, 1992, Revision 1 (Ref. 25).

On July 21, 1992, NRC issued a letter extending the period of applicability of the ITER with Supplement No. I from July 31, 1992 to December 31, 1992 (Ref. 26). An NRC letter issued on December 23, 1992 extended the December 31, 1992 date to January 31, 1993 (Ref. 27).

1.3 USE Hiah-Strenoth Asohalt-Solidification Process The proposed low-level radioactive waste 'ituminization systen, is based on a bitumen solidification system developed by the French Commissariat a L'Energie Atomique (CEA) and a French engineering firm. USE is the licensee for the pro-cess in the United States. The process can use distilled or oxidized asphalt material; however, for this specific TR and the application of the solidifica-tion process, only specific distilled asphalts have undergone the testing ,

program.

The waste streams that the TR addresses are considered typical for light water-reactors and generally result from nuclear-system decontamination efforts and other liquid waste streams from the facility. The waste streams undergo some form of pretreatment before the process of mixing the waste with asphalt. Once the pretreatment has been accomplished, the waste and the asphalt are; metered into an evaporator / mixer unit through which the materials flow by gravity for a minimum resident time. The discharged mixture -- the waste product -- is placed into carbon steel drums that act as molds for the hot mixture exiting the unit (the steel drums are-not relied on as a barrier). Once the drums have cooled and the contents have solidified, they may receive additional bitumi-nized waste before capping, to meet the maximum void space requirements of the drum volume.

3

e 2.0 10p! CAL REPORT

SUMMARY

The TR documents the results of the specific tests USE performed to demonstrate that the waste forms resulting from this solidification process were able to meet the stability requirements of Part 61. The tests were carried out on small-scale 'pecimens of simulated waste, processed in a laboratory bench scale evaporator / mixer. Non radioactive tracers of compounds of cobalt, cesium and strontium were used in the waste formulation. The specimens were generally cylindrical, with a nominal diameter of 2 5/16 inches and a height of 2 3/8 inches, with exceptions being those specimens used for the leach testing, and one cellulosic fiber specimen, used in leach testing, that was a parallele-piped, 2 inches on a side. The cylindrical leach specimens were trimmed to a height of 0.75 inches, to meet the leach test requirements regarding thickness to diameter ratio. The testing program addressed the compressive strengths obtained from the as-mixed waste and bitumen (baseline compressive strength) without this material being subjected to other types of exposure conditions.

Tests were also performed on the pure asphalt material, and on specimens sub-jected to thermal cycling, irradiation, biodegradation, imrrersion and leach tests. Data on the behavior of the waste form produced by this process and subjected to the aforementioned environmental conditions, were obtained during the test program, and provided in the TR. Test results on nearly 300 indivi-dual specimens were reported in the TR, with the test data sheets provided as appendices to the report. Photographs for some _ specimens used for specific portions of the test program are also provided in the appendices. The test program has also included correlation testing of samples produced by bench scale mixing of the processed waste material with samples produced by the full-scale production waste processing system. In addition, samples removed from various locations of the full-scale waste form product have verified the homo.

geneity of the production of full scale waste form product. The process con-trol program (PCP) has also been provided, in conjunction with the TR review, as PCP 001, Revision 1, dated September 9, 1991.

l 3.0 EVALVATION PROCEDURE The review and evaluation of the TR was conducted by NRC staff members with technical assistance from Brookhaven National Laboratories (BNL). In addition, generic information developed by the National Institute for Standards and Technology (NIST) on bituminized low level wastes was also utilized.

The basic document submitted in proprietary form was reviewed and a set of comments and questions were developed from the coordinated effort of HRC staff tnd BNL staff. These comments and questions were issued as a RAI to USE, for action, on September 18, 1990 (Ref. 10), i..e RAI addressed issues resulting from an NRC/BNL detailed review of the original information that USE orovided, '

in accordance with 10 CFR Part 61 requirements and the guidance provided in the

" Technical Position on Waste Form", Rev 0 (TP), (Ref. 2). During the review and evaluation period this TP was revised and reissued as Rev. 1, January 1991 (Ref. 3), with the only major change that impacted this bituminized waste pro-cess being the need for USE to commit to the reporting of mishaps associated with the future use of this solidification process. This had no impact on the work completed, but only addressed the future application of this process, and instances where problems might arise in meeting the design and boundary condi-tions for the waste form product. Consequently, the evaluation has been per-formed and documented against the guidance contained in Rev. 1, January 1991, of the TP.

4 1

L After issuance of the RAI and before a formal response from USE, NRC/USE held a meeting on November 6, 1990, to discuss the issues that USE believed it needed additional discussion on, to be able to respond appropriately in their formal response.

Once the USE formal written responses were received in mid December 1990, NRC and BNL staff reviewed the additional information on the subjects raised by the individual RAls, to determine whether the issue had been resolved, or whether addittor.al information or testing was required. In their formal response to the RAls, USE also requested that the review focus on only a limited number of the specific waste streams. USE suggested interim approvals for this process.

Additional meetings were held on the issues and NRC summarized its evaluation in a position statement on the topical report. USE revised the proposed waste loading for one of the waste streams and requested that NRC not consider the other waste streams until a later date. As a result, an Interim Technical Evaluation Report was issued with a time limit for additional confirmatory testing to be completed. As a result of that testing as well as the previously developed information, this Technical Evaluation Report is being issued for a single waste stream, boric acid concentrates.

4.0 REGU!.ATORY EVALUATION 4.1 Waste Character.istics 4

The minimum set of characteristics that all LLW intended for near-surface land disposal must meet is defined in 10 CFR 61.56(a). These requirements are mainly intended to provide for ease of waste handling and the protection of the health and safety of personnel at the disposal site. All low level radioactive wastes must meet the minimum requirements. Class A wastes that are solidified and disposed of with Class B and Class C wastes must al;o meet the stability guidance for low-level radioactive these wastes, in addition to meeting the minimum requirements.

The characteristics the waste form classified as Class B or Class C, should exhibit, to meet the stability requirements of 10 CFR 61.56(b), are those that will enable the waste form to maintain its stability and package integrity dur.

ing waste-handling and emplacement, as well as after disposal. Stability is intended to ensure that the waste does not structurally degrade and affect the overall stability of the site through slumping, collapse, or other failure of the disposal unit and thereby lead to water infiltration. Stability is also a factor in limiting exposure to an inadvertent intruder, since it provides a recognizable and nondispersible waste.

4.2 Waste Streams Considered The original TR, as submitted, identified seven separate waste streams that are categorized as arising primarily from either (a) the concentration or removal of contaminants from cooling water in a nuclear power reactor, or (b) arising from other liquid waste streams associated with a nuclear power plant. The following waste streams were addressed in the development of the high-strength asphalt waste form product. t l

Boric acid. concentrates with up to 12 weight percent solids; Sodium sulfate concentrates with up to 25 weight percent solids; i

5 i

a 1 I

lon exchange bead resins, t divinylbenzene co polymers;ypically nuclear grade styrene-lon exchange powdered resins that are also styrene divinylbenzene co polymers Cellulosic fiber filter aid associated with polishing filters or in combination with powdered resins on filter elements; Diatomaceous earth that is used on filter elements; and Activated carbon that is used in combination with-precoat filter aids on polishing filters, for the removal of organic contaminants.

However, in the USE response on item RAI 5.02 it was stated, "we request that the review and approval of the Topical Report be limited to the wastes to be processed.... These wastes are boric acid concentrates, bead resins and powdered resins." l As a result of the evaluation of the topical report and the incorporated data, NRC provided USE with an assessment of the application of the proposed solidi-fication process to the three remaining waste streams under consideration (Ref.

14). USE then elected to focus on only one waste stream, the boric acid con-centrates. The actions associated with these events were presented in a letter from NRC to USE, dated May 17,1991 (Ref.16). With the subsequent resolution of specific details, NRC issued interim approval for the boric acid concen-trates waste stream under limited conditions, contingent on additional testing.

An Interim Technical Evaluation Report was issued that addressed this waste 2tream as well as the two resin fems waste streams (Ref. 22).

This Final Technical Evaluation Report addresses the boric-acid concentrates up to 12 weight percent solids.

4.3 tia_ior Review Argn The TR was evaluated against each requirement contained in 10 CFR 61.56, as well as the guidance contained in the TP on Waste Form (Refs. 2 and 3).

The specific subject areas that became major points of discussion included the following items:

Source control and ability to uniquely identify the type of asphalt qualified by the test program; Relationship of simulated waste used in the test program to real wastes; Correlation testing to relate the types of evaporator / mixers used in the test program with the actual production unit; Compression testing in a temperature range-of 50 to 55'Fs and how this relates to temperatures during permanent disposal, after loss of the steel drums used as molds-for the bituminized waste; Large percentage of strength reduction shown by specimens after contact with water; Specimens undergoing the leach testing in some cases exhibited large expansion growth.

6

4.4 Minimum Reoutrements fl0 CFR 61 56(all1 The requirements of 10 CFR 61.56(a) are the minimum requirements for All classes of waste. They are intended to facilitate handling at the disposal site and to provide protection of health and safety of personnel at the disposal site.

4.4.1 Packaging Section 61.56(a)(1) of Part 61 states that waste must not be packaged for disposal in cardboard or fiberboard boxes. The wa:;te form created by the high-strength asphalt solidification process for all waste streams uses a steel drum as the form or mold for the hot, fluid asphalt and thus meets this requirement.

This drum remains as the outer shell of the waste form until the package is placed in the disposal facility.

4.4.2 Liquid Waste As required by 10 CFR 61.56(a)(2), liquid waste must be solidified or packaged in sufficient absorbent material to absorb twice the volume of the liquid.

This waste-form product, high strength asphalt-solidified LLW, does not result in the retention of liquid waste. The solidification process drives off the liquids via the high-temperature Luwa evaporator / mixer. Therefore, the process meets these requirements by being a solidification process.

4.4.3 Free liquid Section 61.56(a)(3) limits the volume of free standing liquid to 1 percent of the volume and encourages the minimization of the volume of free liquids. The USE bitumen process has demonstrated in a full-size 55 gallon drum volume that no free liquid was present in the solidified waste. This demonstration was completed by splitting the drum in half from top to bottom on a diameter. The extraction of specimens from the top, middle, and bottom third also did not reveal free liquids. This specific demonstration was performed in conjunction with a test program associated with the solidification of NS-1 waste as well as on a full-scale waste form produced in the full-scale production process.

This solidification process, operated within the process-control program, will produce a waste form, without free standing liquid, in excess of 1 percent of the waste form volume.

4.4.4 Rehetivity of Product As indicated in 10 CFR 61.56(a)(4), the waste must not be readily capable of detonation or of explosive decomposition-or reaction at normal pressures and temperatures, or of explosive reaction with water. The USE bitumen solidifi-cation process uses asphalt that has an American Society for Testing and Mate-rials (ASTM) 092 minimum flash point of 500'F, which is well above what is con-sidered a normal (ambient) temperature. No adverse effects from pressure or water relative to explosions were observed during handling or testing.

The solidification medium does not appear to introduce any substance capable of detonation or explosive decomposition or reaction at normal pressures and temperatures. Neither does it produce a waste form that has an explosive 7

reaction with water. The waste forms produced by this process thus meet the I requirementsof10CFR61.56(a)(4). '

4.4.5 Toxic Cas Generation l Section 61.56(a)(5) requires that waste must not contain, or be capable cf generating, quantities of toxic gases, va) ors, or fumes harmful to persons transporting, handling, or disposing of tac waste.

Based on observations made to date, the waste form produced by the asphalt solidification process has not generated quantitles of toxic gases, vapors, or fumes in the solidified state. The waste form is, therefore acceptable with respect to no toxic-gas generation.

4.4.6 Pyrophoricity A wasto must not be pyrophoric, as defined in 10 CFR 61.2 and prohibited in 10 CFR 61.56(a)(6) of the regulations. The solidified waste form using asphalt as the binder does not exhibit pyrophoric characteristics, in that under nnrmal conditions, it will not cause fires through friction, or retained heat, nor can it be easily ignited with the minimum flash point being specified as 500'F.

The high strength asphalt is, therefore, acceptable from the standpoint of pyrophoricity.

4.4.7 Gasetus Wastes This solidification process is not proposed for use with gaseous wastes, so that 10 CFR 61.56(a)(7) of the regulation has been addressed.

4.4.8 Hazardous Wastes

! Under 10 CFR 61.56(a)(8), waste containing hazardous, biological, pathogenic, or infectious material must be treated to reduce, to the maximuta extent prac-ticable, the potential hazard from the non-radiological materials. Neither waste-solidification medium of USE's high-strength asphalt,-nor the waste-stream materials identified in the TR contain biological, pathogenic, or infec-tious material. Therefore, the requirements of 10 CFR 61.56(a.(8) have been met.

It should be noted, however, that the NRC TR review of the USE high-strength asphalt-bituminization process did not address any applicable U.S. Environ-mental Protection Agency (EPA) requirements, relating to hazardous solid waste, for which the vendor or waste generator using the USE bituminization process for LLW may be legally responsible, under the Resource Conservation and Recovery Act (WCRA).

Under the RCRA, EPA has jurisdiction over the management of solid hazardous wastes, with the exception of source, byproduct, and special nuclear material, which NRC _ regulates under the Atomic Energy Act (AEA). LLW may.contain source,-

byproduct, or special nuclear materials, but it may also contain chemical con-stituents that are hazardous, under EPA regulations promulgated under Subtitle-C of RCRA. Such wastes are comonly referred to as mixed low level radioactive and hazardous waste (mixed waste).

8

s Applicable NRC regulations control the byproduct, source, and special nuclear material components of the Mixed LLW (10 CFR Parts 30, 40, 61, and 70h EPA '

regulations control ihe hazardous component of the mixed LLW (40 CFR Parts 260-266. 268, and 270). Thus, all the individual constituents of mixed LLW are subject to either NRC or EPA regulations. However, when the components are combined to become mixed LLW, neither agency has exclusive jurisdiction under current Federal law. This has resulted in joint regulation of mixed LLW, where NRC regulates the radioactive component, and EPA regulates the hazardous component of the same waste.

4.5 Etability Reauirements fl0 CFR 61.56fbil and BTP on Waste Form. Rev. 1.

January 1991 The requirements for 10 CFR 61.56(b) are intended to result in waste products with structural stability. Stability is intended to ensure that the waste does not structurally degrade and affect overall stability of the site through slumping, collapse, or other failure of the disposal unit, and thereby lead to water infiltration.

Stability is also a factor in limiting exposure to an inadvertent intruder, since it provides a recognizable and non dispersible waste.

4.5.1 Structural Stability A structurally stable waste form will generally maintain its shysical dimen-stons and its forin under the expected disposal conditions suc1 as weight of overburden and compaction equipment, the presence of moistura and microbial activity, and internal factors such as radiation effects and chemical changes.

The proposed waste forms resulting from the USE high strength asphalt-solidification process have been evaluated for use in direct trench burial, with no benefits derived from the carbon steel drum. The waste form can also be used in improved disposal conditions, such as in a high integrity container or an engineered barrier system that might ("e a concrete vault.

Specimens for use in a testing ;togram, to demonstrate the ability of a specific waste form, resulting from a specific warte stream and solidification process, to meet the regulatory requirements, can be scaled down in size for laboratory work and can be made from simulated waste. That is. an acceptable testing program allows for the use of small laboratory test specimens and the use of nonradioactive waste simulations. When this approach is used there is certain correlation testing that must also be performed. The USE test program roduction of the waste-was based from form material on this approach a Taboratory benchand scale relied as well evaporator on the p/ mixer system..

USE briefly described the siruulated wastes in Section 6.0 of the original submittal and supplemented this information in the response to RAI 6.01. The simulated wastes were non-radioactive and used tracers to facilitate the leach testing that was performed as part of the structural stability testing. The specific tracers used in the three waste streams under evaluation were as follows:

Cobalt nitrate hexahydrate - Co (NO3 ), 6H,0 Cesium nitrate - Cs NO 3 Strontium chloride hexahydrate - SrCl 2 6H,0 -

9

4 The balance of the ingredients were made up of the l,asic waste solution (boric acid concentrates) or slurry (resins), the chemical additives used to adjust the pH or provide chemical pretreatment, water and asphalt. A batch produced by the bench scale evaporator / mixer constituted from 10 to 30 pounds of mate-rial employed as the supply of material used to mold the necessary specimens for each waste stream and the specific bounding parametric limits. USE has stated that other contaminant constituents that may be present in an actual waste stream would have no adverse impact on the stability of the resultant waste form. The contaminants would generally be metallic oxides and other particulates that USE believes serve to strengthen the resulting waste form.

USE has emphasized that the high strength asphalt solidification process is one of physical microencapsulation, in which interaction with contaminants is not chemical, particle. but physical, such as the three dimensional engulfment of a foreign The test data also demonstrate that the compressive strength of a waste form generally increases with increased waste loading, for the ranges studied, when compared to the pure bitumen.

Based on staff's review of the test data and understanding of the type of interactions existing between and the waste constituents the bitumen binder, the staff believes the waste stream simulations are adequate.

Test specimens used in the test program were generally cylinders, with a 2 and 5/16 inch diameter, and with a height targeted for a nominal value equal to the diameter (i.e., L/d = 1), but varying as a result of the molding process, the trimming process, or the requirements of another test. The basic dimensions were set, based on working within the guidance of ASTM D1074, for compressive strength testing. Specimens used in the leach testing were triumed to a nomi- .

nal height of 0.75 inches. In general, when specimens were to be subjected to compression test, three specimens were tested, and the average strength reported.

The staff has determined that the test specimens used in the test program are adequate, with respect to their physical dimensions and the numbers of spect-mens are adequ=te. '

(a) Baseline Compressive Strength The guidance provided in the TP Indicates that the solidified waste specimens should nave a compressive strength of at least 60 psi, when tested under the requirements of ASTM 01074. The guidance also notes that some solidification media can produce strengths in excess of this minimum value, and the process control parameters should be developed to achieve the maximum practical compressive strength.

The compressive strength was determined on the basis of the stress at a 10 percent deformation of the specimen, unless failure occurred prior to that strain, in which case, the strength at failure was used as the compressive strength.

The temperature conditions under which the tests were conducted varied from the values listed in ASTM 01074. This standard states that the test tempera-ture should be 77'F t 1.8'F. The tests were conducted on samples conditioned at 50 to 55'F t 5'F, removed from the control chamber, and moved to another -

building for testing. Specimens were subjected for up to I hour to the ambient 10

L environment temperatures during these activities. In ressonse to RAI 7.01, which was related to test temperatures. USE provided the aistorical basis for a 55'r test temperature. The staff has not as yet defined a minimum test tem-perature that can be directly related to the temperatures the waste form would actually experience after disposal. Recognizing the staff's concern over the issue of temperatures, during the compression teste, USE conducted additional l compressive testing at 77'T on samples of the waste form, from the boric-acid waste stream, that were made with material from the full-scale processing sys-tem. These tests demonstrated that the product still maintains a significant compressive strength margin above the 60 psi. The 20f' temperature increase resulted in a strength reduction of approximately 50%.

Three specimens made of the dirtilled pure asphalt were tested in the USE test program. The resulting average compressive strength was 430 psi. This exceeds the strength usually associated with the oxidized asphalts. Compressive-strength tests performed on the boric acid bituminized waste resulted in strengths exceeding that of the pure asphalt. The range of values was from 1055 to 1185 psi. The standard deviations varied from 35 to 65 psi. These are acceptable results and apparently demonstrate that the incorporation of solid particles in the form of the t W products enhances the compressive strength in the unconfined condition. This also provides some support for USE's position relative to the effects of additional contaminants or particulate materials in the simulated waste, as discussed at the beginning of Section 4.5.1.

The 60 psi minimum has been met for the boric-acid wastes, and the formulations '

provide for excess strengths, based on the baseline compression tests (con-ducted on baseline, as fabricated materials that have not been subjected to adverse environmental conditions).

l (b) Thermal Cycle Resistance l

The guidance provided in the TP on waste form states that solidified waste forms should retain minimum compressive strengths greater than 60 psi, after 30 thermal cycles between 60*C and 40'C, as provided for in ASTM B553. The origi-nal submittal on the conduct of the testing was supplemented by the response to RAI 7.25.

The thermal cycling tests for the boric acid waste stream yielded after-test compression strengths of over 900 psi for the waste pretreated to a range of pH levels. Thus, the acceptance criterion for this test was met for the boric-acid waste form.

I (c) Radiation Resistance As noted in the TP, the waste form should remain stable after being exposed in a radiation field equivalent to the maximum level of exposure expected from the proposed waste form. Specimens undergoing this test should be exposed to a minimum of 10' rad in a gamma irradiator or equivalent, if the maximum level-of exposure of the actual waste form is expected to exceed 10' rad, then the test of the specimens should be conducted at the expected level of maximum accumulated dose. After specimens have been irradiated, they must be subjected to an unconfined compression strength test, with the resulting strength to exceed a 60-psi minimum.

11

_ _ _ _ . ~ . -

,-- - - - - -- - _ - . - - - . ---- - - ~ _ - -

' The tests on the irradiated specimens for the unconfined compressive strength resulted in values in excess of 800 psi for the boric acid waste form. The values were well above the 60 psi minimum value indicating an acceptable waste form.

(d) Biodegradation Resistance l The guidance provided in the TP on waste form states that the waste forms should be tested for resistance to biodegradation, in accordance with ASTM G21 and ASTM G22. After these tests, there should be no indication of culture growth, and the specimens should be compression tested, in accordance with ASTM 01074, with a minimum strength value of 60 psi. Visible growth arising from contamination, additives, or bio 6qradable components may not relate to the integrity of the substrate. If culture growth does occur, a second level of tests is conducted. Failed specimens (those that have supported microbial culture growth) are washed with water and light scrubbing, and the surface of the samples extracted with an appropriate organic solvent, if necessary. After washing and air drying at room temperature, the samples are tested again using the ASTM G21 or G22 procedure, as appropriate. Waste forms are considered to have passed at the second level of tests if microbial culture growth is not visible for the G22 test, or if growth does not exceed a rating of 1 in the G21 test.

If failure at the second testing level occurs, the TP recommands that blode-gradation rates in soil be determined using the Bartha-Pramer method (Ref.17).

Soils used in this test should be representative of those at disposal sites.

Degradation rates determined from this procedure are to be extrapolated for full-size waste forms to 300 years. Waste forms pass this test if the extra-polation indicates that biodegradation will cause less than a 10 percent loss of the total carbon in the waste-form. The minimum time recommended for the Bartha Pramer testing is 6 months. No compression tests are required after l this test.

USE had to perform the second level of tests on only one boric-acid sample since all others passed the initial G21 and G22 tests. After the wash and light scrubbing of the specimen, a retest started, with the results showing no growth. The compression strength of the boric acid specimens illustrated strengths ranging from 850 to 1085 psi. The guidance on blodegradation testing i was, therefore, fully met by the boric-acid waste form.

(e) Leach Resistance I The TP provides guidance on the performance of leach testing, followed by the compressive strength test. The leach testing is to be performed in accordance with ANS 16.1, for a minimum of 90 days. The ANS 16.1 leach test should be performed using demineralized water and synthesized seawater as the leachant, i

For nuclear power plant waste streams, the tracers suggested are cobalt, cesium, and strontium, and the leachability index should be greater than 6.0, when calculated in accordance with ANS 16.1.

The leach tests performed on the ooric-acid waste form produced leach indices ranging from 7.77 to 10.91, in demineralized water. The indices ranged from 7.88 to 9.90, in the simulated seawater. The tests were serformed with the suggested tracer elements. A statistical analysis also slowed that there is a [

12

99.9 percent conficence that the leach index, based on the testing is greater than 6.60.

(f) Immersion Resistance The TP on waste form suggests that after a period of 90 days of immersion, a '

specimen subjected to an unconfined compression test under ASTM D1074 should '

maintain maximum practical compressive strengths.

The waste forms derived from the boric-acid waste stream demonstrated a distinct difference in behavior, with respect to two variables that, based on the test program, could not be ' 'ablished as being independent variables. Two data points were obtained in the test program, for the boric acid waste form.

These were controlled by the pH of the waste bitch and the waste loading of the resulting waste form, but the influence of each variable could not be defined with the available data. The two data points represented a pH of 7.0 and a waste loading of 50.68 weight percent, and a pH of 9.0 and a waste loading c1 43.85 weight percent. In the first case, the immersion test resulted in a 92 percent loss in compression strength, down to a level of 95.5 psi i 28.9 psi, making the minimum value 66.6 psi. In the second case, the immersion test had no great detrimental effect on the compressive strength, yielding a value of 1074.5 1 116.6 psi, making the minimum value 857.9 psi. Although all the test specimens had compressive strengths greater than 60 psi, the larger (92%)

reduction in strength for the pH 7.0, 50% waste loading specimen provided a clear indication that the test specimen was not in a stable condition at these waste loadings.

(g) Correlation Testing The TP indicates that if small simulated laboratory-size specimens are used for the testing program, test data from sections er cores of the anticipated full-scale products should be obtained to correlate the characteristics of actual-size products with those of the laboratory specimens.

The constituent materials were processed in a bench-scale processing arrange-ment with the evaporator / mixer stated as being a' unit similar to the Guedu hench-scale evaporator / mixer used by the CEA-in the original development of the-bitumen-solidification process. USE completed correlations by comparison of these bench scale processed materials with material produced by the full scale production equipment. The results indicated that the full-scale equipment pro-duced a waste form product with lower moisture and a higher strength. This is apparently due to the more turbulent mixing and higher heat transfer in the full-scale production equipment when compared to the bench scale process.

Based on the data, the staff Las concluded that good corrolation has been demonstrated between materials produced by the bench-scale and full-scale production.

(h) Determin tion of Homogeneity The TP recommends that samples from full-scale specimens should be destruc-tively analyzed to ensure that the waste form produced is homogeneous to the extent that all regions in the product can be expected to have physical and chemical properties representative of the. physical and chemical properties of the laboratory-scale specimens. Specimens should be fabricated using ,

13

r b

i solidification equipment that is the same as, or comparable to, that used in the field for actual llW.

USE completed homogeneity testing of a full size drum specimen of treated boric acid concentrates that had been produced by the full scale production process.

The material was produced at a solids loading of 40 wt% at a pH of 9.0. The final waste form, in this case a drum, was split lengthwise and material was extracted from the top, middle and bottom of the halves. The material was heated and reformed into molds to produce three approximately 2-1/4 inch dia-meter by 2 1/4 inch high cylinders from each region. These were tested for compressive strength, moisture content and solids content. The moisture con-tents were all below the oetection limit of 0.1% and the compressive strengths for the three regions were 429,595 and 473 psi from bottom to top. The waste loadings ranged from approximately 38.5 to 41.0 wt %.

It is concluded that the material can be produced and solidified into a homogeneous product.

(i) Dimensional Stability The regulations state that to possess structural stability, the waste form will generally maintain its physical dimensions and form under the expected disposal conditions.

For the boric-acid waste streau treated to a pH of 7.0, the available test data from the immersion tests indicate a radial growth of 22 percent, as a result of water contact. The leach tests resulted in dimensional growth that produced a volume change of +54 percent, on contact with demineralized water. USE, in responding to RAI 7.08, with regard to the dimensional growth of the waste forms, indicated that the growth observed in the small-laboratory specimens is related to the specimen size and would not occur in a full scale waste form product. The USE position is that the water only penetrates into the outer 1/2 inch thick shell of the entire waste form and consequently, the impact is greater on the small specimen than it would be in full scale waste forms. USE '

has performed a calculation based on the assumption of only 1/2 inch of water penetration into a 55 gallon drum, to demonstrate that the resulting volume increase would only be 10 percent, not a value of 50 percent or more. The basis for the claimed 1/2 inch of penetration has not been provided to the NRC staff; therefore, the staff must rely on the actual results observed from the laboratory-size specimens.

Based on the data currently available, the boric acid waste form, derived from the boric-acid waste stream treated to a pH of 7.0, does not exhibit the char-acteristics that would indicate dimensions will generally be maintained. By 4 process of deduction (and definition) therefore, such waste-forms lack the long-term structural stability required by Part 61. 4 For the boric-acid waste stream treated to a pH of 9.0 and solidified at a waste loading of 43.8b weight percent the available immersion test data indi-cate a radial growth of 1 percent apparently from the contact with water. The leach tests resulted in dimensional growth that-produced a volume change of approximately +30 percent (radial component of growth of 1%) for contact with simulated seawater or demineralized water. Based on the data, the NRC staff has concluded that production of the waste form product at a pH of 9.0 with a waste loading of 40 wt% results in a stable material.

14

-. - - . . . . .. - ~ . - - __ .

4.5.2 Free Liquids

• The regulations require that when a waste 1.3 processed into a stable waste form, the maximum amount of free liquid permitted is 0.5 percent of the volume of the waste. During the test program conducted on the laboratory size speci-mens, there were no instances where free water was observed to remain on the specimen. No free liquids were observed on the full-size 55 gallon drum that was cut open in the USE full-scale testing. It is concluded that the waste form produced by this process will not contain free liquids.

4.5.3 Void Spaces The regulations indicate that the void spaces within the waste must be reduced to the extent practicable. USE's bitumen solidification process results in a viscous fluid made up of the asphalt and the waste-stream constituents which flow out of the evaporator / mixer nozzle at a rate not exceeding 50 gpm. This flows into a 55 gallon steel drum and solidifies in a me.nner that apparently traps few volds. The report on additional testing USE completed on full-scale drums, and the removal of material for other tests did net reveal any signifi-cant voids. Based on the current data, the ws.ste forms produced by this.

process appear to minimize void space within the matrix.

4.6 Waste and Moisture Content of Waste Form To ensure that the processing of nuclear power plant wastes will consistently produce an acceptable product for placement into a disposal facility, it is required that plant licensees process the wastes in accordance with a plant-specific PCP. A TR should contain a generic PCP that will define the necessary controls required to consistently produce the same waste form in a production mode that resulted from the formulations completed in the testing program con-ducted in the laboratory. Two important control parameters in any such PCP would include the waste loading in terms of weight percent of the total solids, and the moisture content of the waste form.

For the boric acid waste stream, USE reported on two data points with regtid to the moisture content and the- total solids of the waste-forms. As was discussed in Section 4.5.l(f) of this ITER, the impact of the two variables could not be separated, due to the sparsity of reported data. The tests were aerformed with (1) a pH of 7.0 and a waste loading of 50.68 percent (solids weig1t percent) and (2) a .oH of 9.0 and a waste loading of 43.85 percent (solids weight per-cent). The bound moisture ranged form 0,13 to 0.17 weight percent. USE com-pleted some additional testing at the pH and waste-loading values to be used in production and has determined that the moisture content is consistently below the detection limit of 0.1 wt.%. The data obtained from production runs authorized under the interim authority has been closely maintained at the 40.

wt.% range of waste loading, indicating good-system control in the process.

Based on all the data, NRC has concluded that an acceptable waste form product can be produced by the process operated within the defined limits.

4.7 Process Control Proaram and Opality Control USE submitted a revised Interim PCP, known as Document No. PCP-001,-Revision 1, dated September 9, 1991. for the tolume reduction and solidification system.

In addition, on September 19, 1991, page 15 of PCP-001, Revision I was modified i 15 o

l

. as requested by NRC.

The resulting interim process control program has pro-vided an adequate means to control the quality of the resulting product from the boric acid waste stream based on the interim production results. There-fore, based on the actual productica process and the test results the interim process the TR, control program can be considered a final process control program for Testing completed by USE indicated that operation of the system under the PCP results in bound moisture contents of less than 0.1 wt.% n4oisture, which is the effective detection limit.

4.8 8toortino of Mishaos As a result of the recent revision to the " Technical Position on Waste Form,"

dated January 1991, vendors and processors are included in the group who are requested to report mishaps. For the USE high strength asphalt process, the following types of mishaps are examples of instances that should be reported for solidified Class B or Class C waste forms exhibiting one of the following characteristics:

greater than 0.5 percent volume of free liquid.

concentrations of radionuclides greater than the concentraticia demonstrated to be stable in the waste form, in qualification testing accepted Dy the regulatory agency._

greater or lessor amounts of solidification media than were used in qualification testing accepted by the regulatcry agency.

contains chemical ingredients not present or accounted for in qualification testing accepted by the regulatory agency.

shows instability evidenced by crumbling, cracking, spalling, voids, softening, disintegration, nonhomogeneity, or change in dimensions, evidences processing phenomena that exceed the limiting processing conditions identified in applicable TRs or PCPs, such as foaming, excessive temperature, premature or slow hardening, production of volatile material, etc.

Waste form mishaps should be reported to NRC's Director of the Division of Low-Level Waste Management and Decommissioning, U.S. Nuclear Regulatory Commission,

, Washington, D.C. 20555, and the designated State disposal-site regulatory authority, within 30 days of knowledge of the incident. For any such waste-form mishap occurrence, the affected waste form should not be shipped offsite until approval is obtained from the disposal-site regulatory authority. The reason for this is that the LLW generators and processors are required, by 10 CFR 20.311, to certify that their waste forms meet all applicable require-ments of Part 61, and waste forms that are subject to the types of mishaps just mentioned may not possess the required long term structural stability. When mishaps of the nature just described occur, it is expected that, before the waste form is shipped to a disposal facility, either adequate mitigation of the potential effects on the waste form or an acceptable justification concerning the lack of any potential significant effects of the affected waste form on the overall performance of the disposal facility wo:id be provided.

5.0 REGULATORY POSITION in the evaluation of the USE topical report, the NRC staff reviewed the waste-form qualification test data for three waste streams (boric-acid concentrates, bead-resins and powdered resins) to determine the resulting waste forms' compliance with Part 61 criteria and conformance with the current " Technical 16 I

4 Position on Waste Form", 1/91, Rev. 1. The TR, USE Ho. 61 002 P, June l'9, -

1989, and the supalemental information provided are acceptable as reference documents for asp 1 alt-solidified waste produced into a waste form by the USE process system subject to the listed conditions.

Boric acid concentrates con-forming to the TR and treated by the process will result in a waste form that meets the requirements of 10 CFR 61.56.

5.1 Limitations The limitations for the use of this process are based on the type of waste stream, qualification of plant specific waste streams, process control, waste containers, and disposal backfill provisions.

5.1.1 Withdrawn Waste Streams l The waste strearas designated as sodlem sulfate concentrates, cellulosic filter aid, diatomaceous earth, activated carbon, bead and powdered resins are ant. {

approved fur use with the USE high-strength asphalt solidification process, since the evaluation was ended before completion, at USE's request. These may be addressed later by USE, at which time NRC will re evaluate any new data and modify this TER as necessary.

5.1.2 Boric Acid Conce crates l

The waste stream designated as boric-acid concentrates is granted a final approval.

For this waste stream to be processed with the USE high strength asphalt system, the waste stream should be treated to a pH of 9.0 (+0.5; -0.0) and the waste loading limited to no more than 40 weight percent. These limits are being imposed as a result of the available test data that reflected the results of testing performed by USE. While the compression strength test data met the acceptance criteria in the TP, the staff has concluded that structural stability requirements of 10 CFR 61.56 (b) had not been met for some of the specimens tested within the pruposed entire range of parameters encompassed by the test program. Specifically, the boric acid waste stream treated to a pH of 7.0 with a waste loading of 50.68 weight percent exhibited sufficient.dimen-sional growth so as to produce a volume increase of 54 percent upon contact with water, during the leaching tests. At a pH of 9.0 and a waste loading of 43.85 weight percent the volume expansion was approximately 30 percent from the leach tests. Consequently, the NRC staff set limits for the processing of the boric-acid concentrates waste stream.

5.1.3 Waste Containers The waste form will be deposited, in a thermally hot condition, from the Luwa evaporater/ mixer, into 55 gallon steel drums. These drums vere not considered as contributing to the stability of the waste form. High-integrity containers (HICs) would also be acceptable if the nozzle discharge conditions, such as high temperature, from the evaporator / mixer can be tolerated by the high-integrity container materials of construction.

5.1.4 Process Control l The waste form shall be prepared using the procedures specified in the revised PCP-001, Revision 1, dated September 9, 1991 with page 15 revised by Engineer-ing Revision Authorization 237-ERA-001, dated September 19, 1991.

17 a

l

. _a

4 5.1.5 Disposal Backfill Restrictions li Bitumen can exhibit viscoelastic creep deformation under applied vertical loads, when improperly confined in the lateral direction. To retard creep deformation, NRC recommends that an administrative backfill procedure be used to control the filling of void spaces during the waste form emplacement (as provided for in Section 4.3 of the Standard Review Plan, NUREG-1200), to ensure adequate confinement, when the waste form is disposed of without the use of a fully qualified high integrity container that can itself sustain the applied load of the disposal trench.

g 5.2 Summarv Final approval is granted for the boric acid waste stream, under the following l conditions:

Boric acid concentrates with up to 12 weight percent solids. I Pretreatment to a pH of 9.0 (+0.5; - 0.0).

Waste loading limit not to exceed 40 weight percent.

Free liquids in the waste form shall not exceed 0.5 percent, by volume. 3 Bound moisture in the waste form not to exceed 0.2 weight percent, i

Based on staff's review of the data, it is concluded that there is reasonable assurance th t the resulting waste form pioduct will meet the requirements of Part 61. '

6.0 BEFERENCES

l. Code of Federal Regulations. Title 10, Part 61, " Licensing Requirements for Land Disposal of Radioactive Waste," Nuclear Regulatory Commission, Washington, D.C., January 1, 1991.

2. U.S. Nuclear Regulatory Commission, " Technical Position on Waste Form,"

Rev. O, May 1983.

L

3. U.S, Nuclear Regulatory Commission, " Technical Position on Waste form." i Rev. 1, January 1991.

4. Letter from Steve Simpson (USE), to Michael Tokar (NRC), dated July 13, 1989.

5. Letter from John Surmeier (NRC), to Steve Simpson (USE), dated July 27, 1989.

6. Letter from Robert Shewmaker (NRC), to Steve Simpson (USE), dated October 5, 1989.

7. Letter from Robert Shewmaker (NRC), to Steve Simpson (USE), dated October l 27, 1989. *

8. Letter from Robert Shewmaker (NRC), to Steve Simpson (USE), dited May 3, 1990.

18

9. Memorandum from Robert Shewmaker (NRC), through Michael Tokar (NRC)'to Paul Lohaus (NRC), dated Jar,uary 10, 1991.

10. Letter from Michael Tokar (NRC), to Steve Simpson (VSE), dated September 18, 1990, with Request for Additional Information (RAl-1),

11. Memorandum from Robert Shewmaker (NRC), through Michael Tokar (NRC) to John Surmeier (NRC), dated December 3, 1990,

12. Letter from Steve Simpson (VSE), to Michael Tokar (NRC), dated December 14, 1990, enclosing RAl-1 responses, Test Plan and Process Control Program.

13. Letter from Steve Simpson (VSE), to Michael TMar (NRC), dated December 31, 1990,

14. Letter from Paul Lohaus (NRC), to Oscar Wong (VSE), dated April 26, 1991. -

15. Memorandum from Robert Shewmaker (NRC), through Michael Tokar (NRC) to Paul Lohaus (NRC), dated May 16, 1991.

16. Letter from Paul Lohaus (NRC), to Oscar Wong (USE), dated May 17, 1991,

17. Bartha, R. and Pramer. D., " features of a Flask and Method for Measuring the Persistance and Biological Effects of Pesticides in Soils," 191].

Science, 100(1), pp.68-70, 1965.

18. Letter from Michael Tokar (NRC), to Oscar Wong (USE), dated August 2, 1991, transmitting the ITER of July 1991.

19. Letter from Oscar Wong (USE), to Michael Tokar (NRC), dated September 10, 1991.

20. Letter from Michael Tokar (NRC), to Oscar Wong (USE), dated September 16, 1991,

21. Letter from Oscar Wong (USE), to Michael Tokar (NRC), dated September 23, 1991.

22. Letter from Joseph Kane (NRC), to Mark Cade (VSE), dated January 24, 1992, issuing Supplement No. I to the ITER.

23. Letter from Mark Cade (VSE), to Joseph Kane (NRC), dated March 17, 1992, submitting a test plan for comment.

24. Letter from Joseph Kane (NRC), to Mark Cade (VSE), dated April 16, 1992, indicating the test plan addresses the issues defined in Section 5.2.1 of the ITER.

25. Letter from Mark Cade (USE), to Joseph Kane (NRC), dated July 17, 1992, transmitting the Test Report, Revision 1, dated July 9, 1992.

26. Letter from Joseph Kane (NRC), to Mark Cade (VSE), dated July 21, 1992, extending the ITER with Supplement No. I for use until December 31, 1992.

19 i

l

r 27.

Letter _fromJohnThoma(NRC),toMarkCada(USE),datedDecember'23,1992 extending the ITER with Supplement No. I for use until January 31. 1993. (

)

i

+

5 20

' - ~ ~

, c.w.. , -.m . . , . . . ,

. .b