Issue Date: 10/05/01 - 1 - 2620

NRC INSPECTION MANUAL FCLB

MANUAL CHAPTER 2620

ON-SITE CONSTRUCTION REVIEWS OF REMEDIAL ACTION AT

INACTIVE URANIUM MILL TAILING SITES

(TITLE I, URANIUM MILL TAILINGS RADIATION CONTROL ACT)

2620-01 PURPOSE

The purpose of this instruction is to provide guidance for planning and conducting on-site

construction reviews of the remedial action to stabilize inactive uranium mill tailings sites.

The work is under the direction of the Department of Energy (DOE) under the authority of

the Title I, Uranium Mill Tailings Radiation Control Act of 1978. The Act requires the

Nuclear Regulatory Commission to concur with DOE selection and performance of actions

to stabilize the sites and, following those actions, to license DOE or such other Federal

agency that the President may designate for the long-term care of the completed sites.

2620-02 OBJECTIVE

This Chapter establishes the program to be used by NRC reviewers monitoring the

remedial action work carried out at inactive uranium mill tailings sites by DOE and DOE

contractors.

2620-03 DEFINITIONS

03.01 Remedial action. Those work activities carried out to stabilize mill tailings, clean

up the processing site, and otherwise perform work to assure the site and tailings pile will

conform to the Environmental Protection Agency (EPA) standards for inactive sites.

03.02 On-Site Construction Review. Includes all the efforts necessary to monitor the

remedial action at inactive tailings sites, including, but not limited to, examination or

evaluation of a program or activity. The majority of the remedial action subject to an onsite construction review is "earth moving" work. The review will determine compliance with

the Remedial Action Plan (RAP), but will not include enforcement action, as NRC does not

have the enforcement authority for this program under the Act.

2620-04 RESPONSIBILITIES AND AUTHORITIES
2620 - 2 - Issue Date: 10/05/01

04.01 Program Management, Policy Development, and Analysis, Office of Nuclear

Reactor Regulation. Develops and issues requirements, guidance, and procedures for the

NRC inspection program, and modifies the program as necessary based on experience,

performance, and other factors.

| 04.02 Division of Fuel Cycle Safety and Safeguards, Office of Nuclear Material Safety

and Safeguards. The Division develops and issues policy, guidance, and procedures for

the Uranium Recovery Program; directs and carries out the NRC program for evaluation

and concurrence with DOE remedial action plans for cleanup of inactive uranium mill

tailings sites and contaminated vicinity properties under Uranium Mill Tailings Remedial

Action (UMTRCA); and performs on-site construction reviews of remedial actions covered

by this procedure.

2620-05 BASIC REQUIREMENTS

05.01 The foundation for planning and scheduling reviews during remedial action at

inactive tailings sites is the RAP, prepared by DOE and its contractors and issued with

NRC concurrence. This plan includes criteria for all phases of the proposed remedial

action.

The RAP contains the construction specifications and the basic elements of the remedial

action but does not always contain specific criteria or procedures for carrying out the

testing and quality control inspection during construction. The specific criteria and

procedures not included in the RAP are developed by the DOE contractor performing the

remedial action at the site. Those procedures are designed to control, verify, and

document all remedial action at the site and are referred to collectively as the Remedial

Action Inspection Plan (RAIP). The RAP and RAIP are the primary commitments and

standards used as a basis for the NRC reviews of the remedial action work.

05.02 The basis and criteria for reviews for a particular site will be the RAP, the

construction specifications provided in the RAP, and the associated RAIP. Guidance for

conducting the reviews shall be incorporated into the procedures appended to this Chapter

(Appendix A).

05.03 The lead reviewer shall develop and prepare an On-Site Construction Review Plan

(OCRP). See Appendix B for an example. The OCRP will be approved by the other review

team members and the lead reviewer's immediate supervisor before the review. The

extent and detail of the OCRP will vary with the type, length, and complexity of the review.

Most review requirements are covered by the procedures stated in this Inspection Manual

Chapter.

05.04 The foundation for planning and scheduling reviews will be the DOE schedule for

the site and the DOE contractor's construction schedule for the remedial action work.

05.05 Because of the need for close coordination with the construction activities, routine

reviews will normally be performed on an announced basis rather than unannounced, as

is the present NRC policy for inspection of its licensees. The NRC shall provide notification

to the DOE UMTRA Project Office at least five days in advance for any routine review to

enable a DOE representative to be present.
Issue Date: 10/05/01 - 3 - 2620

05.06 As appropriate, the review effort will be weighted toward direct observation of work

activities. Written and photographic records will be reviewed as necessary. The review

process shall include photographic recording of critical work phases, processes, or

milestones, as necessary for the record.

05.07 To the extent practicable, review of remedial action at a site should be performed

by individuals who have not been directly involved in the review. It is recognized, however,

due to staffing levels, that some of the review team members will be cognizant of the sitespecific aspects of the RAP.

05.08 Results of each review shall be conveyed to the DOE management

representative(s) at a closeout meeting (exit interview) immediately following the review.

Attendance at the closeout meeting by DOE contractors should be at the discretion of

DOE.

05.09 The closeout meeting (exit interview) participants will include the most senior DOE

participant present. During the closeout meeting, the DOE representative should be made

aware of the preliminary findings, including any apparent items of noncompliance with the

RAP. In accordance with Manual Chapter 1007, the reviewers also will address safety

concerns in the area of Occupational Safety and Health Administration (OSHA)

responsibility. The reviewers will inform DOE representatives and notify the NRC Regional

Office OSHA Liaison Officer, of non-radiological hazards brought to their attention by site

personnel or observed during the review. OSHA decisions will not be made by NRC

personnel.

05.10 Resolution or schedules for commitments to resolve NRC concerns should be

requested from DOE within 30 days of the review report date.

05.11 The basic procedures for the review program are appended to this Chapter.

05.12 In general, the review program at each site should be scheduled, such that the

following construction milestones are observed, as appropriate:

a. During the early stages of remedial action, depending on site-specific design

aspects, review of foundation preparation, placement of capillary break, liner, or

tailings/contaminated material should be performed;

b. During construction of the radon barrier and frost protection soil cover; 

c. During placement of erosion protection (rock cover); and

d. At or near the completion of remedial action (closeout review).

Multiple construction activities should be reviewed simultaneously when the schedule

permits; however, at least one review during the construction year should be conducted,

if construction activities are occurring. Additional reviews should be performed when

warranted, if project-specific design/construction phases include critical work phases or

features not identified above. Examples of project-specific design/construction activities

may include, but not be limited to, aggregate production, bentonite amendments for radon

covers, slurry wall construction, ground modification, and monitoring well activities. The
2620 - 4 - Issue Date: 10/05/01

NRC closeout review will be conducted independently of DOE's final inspection. However,

the final NRC review and DOE inspection may be conducted concurrently. In accordance

with procedures in the UMTRA Project Operations Manual, Section 9.2.10, DOE will notify

the NRC staff of the schedule for closeout reviews. 

END

Appendices:

A. Uranium Mill Tailings Remedial Action Project

 On-Site Construction Review Procedures

B. On-Site Construction Review Plan (Example)

C. On-Site Construction Review Report (Example)
Issue Date: 10/05/01 A-1 2620, APPENDIX A

APPENDIX A

URANIUM MILL TAILINGS REMEDIAL ACTION PROJECT

ON-SITE CONSTRUCTION REVIEW PROCEDURES

A. OBJECTIVES

The objectives of the on-site review of remedial action construction are as follows:

1. To determine by direct observation if remedial actions are being accomplished in

accordance with specifications and procedures.

2. To determine whether the system for preparing and maintaining records is

functioning properly.

3. To determine whether records reflect work accomplishment consistent with

specifications and procedures.

4. To determine if the records and/or work activities indicate any generic problems,

inadequacies, or other weaknesses that could impact the acceptability of remedial

action.

B. PREPARATION

Applicable portions of the Remedial Action Plan, the final design, and the Nuclear

Regulatory Commission/the Department of Energy comments and responses should be

reviewed to determine construction requirements and DOE's Inspection Plan before

performing the on-site review. The reviewer should then utilize these documents in a

detailed review of the construction specifications, drawings, and Remedial Action

Inspection Plan.

C. WORK OBSERVATION

By direct observation of earthwork and other activities in progress, the reviewer should

ascertain whether applicable activities are being controlled and accomplished in

accordance with the requirements of the documents reviewed. Reviews will generally be

conducted by a geotechnical engineer, surface water hydrologist, hydrogeologist, or health

physicist as appropriate, depending on the nature of the review item. Key construction

milestones (listed in Table 1) should be observed as directed in Section 05.12 of this

Chapter. During construction reviews, the reviewer should also determine the locations of

ground-water monitoring wells and observe their condition. If ground-water sampling is in

progress, the procedures should also be observed. Specific procedures applicable to

particular construction and monitoring activities that may be viewed on a site-specific basis

are as follows:

1. Test Fill Construction
2620, APPENDIX A A-2 Issue Date: 10/05/01

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed.

b. Visually check the barrier test zone to ensure proper thickness and material

type.

c. Observe gradation, bentonite amendment operations (if applicable), plasticity

index, and moisture/density testing, and compare results of tests with

specifications.

d. Observe installation of instrumentation/testing/monitoring equipment,

including infiltrometers where applicable.

e. Review quality control plan and infiltration test results.

 2. Foundation and Subgrade Preparation

a. Check to ensure that the subgrade is cleared of all vegetation and topsoil,

shows no deterioration due to frost action or erosion, and exhibits no rutting

from construction vehicles.

b. Check to ensure that the subgrade exhibits no areas of subsidence, extreme

surface drying, or localized ponding (overly wet areas).

c. Observe proof rolling operations or density testing; if density testing is

performed, compare results of tests observed in the field with specifications.

3. Placement of Capillary Break

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed.

b. Observe the capillary break zone to verify proper thickness and material

type, and to ensure that segregation of materials has not occurred.

c. Observe gradation and/or moisture/density testing and compare results of

tests observed with specifications.

4. Placement of Seepage Barrier/Liner

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed.

b. Visually check the liner zone to ensure proper thickness and material type.

c. Observe gradation, plasticity index, and/or moisture/density testing and

compare results of tests observed with specifications.

5. Placement of Contaminated Materials
Issue Date: 10/05/01 A-3 2620, APPENDIX A

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed. This includes checking the

loose-lift thickness (during placement) against the specifications.

b. Visually check the quantity, maximum size, and distribution of foreign

material, and the distribution of organics against the allowable criteria of the

specifications. Also, note if large areas of slimes and/or non-homogeneous

areas exist.

c. Observe moisture/density testing and compare results of tests observed with

specifications. Note any ponding, runoff, or dust conditions.

d. Observe radiological monitoring (health and safety, as well as radionuclide

concentration measurement).

6. Placement of Soil Cover (Radon Cover)

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed. This includes checking

required loose-lift thickness and proper blending of any additives, and if

method specifications for density have been established by test fill,

verification of number of equipment passes.

b. Visually check cover layer(s) to ensure proper material type and final

thickness for each layer.

c. Observe gradation, plasticity index, and/or moisture/density testing and

compare results of tests observed with specifications.

7. Placement of Frost Protection Layer

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed. Check required loose-lift

thickness, and if method specifications for density have been established,

verify number of equipment passes.

b. Visually check the frost protection cover layer to ensure proper thickness and

material type.

c. Observe gradation, plasticity index, and moisture/density testing and

compare results of tests with specifications.

8. Placement of Bedding Layer(s) and Rock Cover (Riprap)

a. Observe placement and compaction operations to ensure that procedural

and equipment requirements are being followed. For the rock cover and

other riprap layers, this includes checking that placement techniques are

conducted in a manner that prevents material degradation, assures uniform

distribution and minimizes voids.
2620, APPENDIX A A-4 Issue Date: 10/05/01

b. Visually check the bedding zones and riprap layers to ensure proper

thickness and material type for each zone, measuring as necessary. If

possible, excavate by hand to a sufficient depth to verify thickness by

measurement.

c. Visually check riprap for approximate size (maximum, average). If possible,

excavate by hand to verify size of underlying rocks, measuring as necessary.

d. Observe gradation testing to assure that representative samples are being

tested.

 e. Observe gradation testing of filter and rock layers and compare results of

gradation and durability tests observed with specifications and RAP

requirements.

9. Other Potential Construction Observations

a. Check operations at borrow areas and quarries; verify that any procedures

for moisture control are properly conducted; and visually check that material

type(s) are consistent with specifications and are representative of materials

actually being placed.

b. Check layout of diversion ditches. Check for conformance to design

configuration and riprap requirements.

c. Check overlap and integrity of geotextile separators, if they are used.

d. If an approved vegetative cover is used in place of rock cover, check to

ensure uniform seeding, use of specified seed type, seed density, etc.

e. Check overall site grading to assure that cut and fill procedures will not result

in grading which would be susceptible to future surface erosion.

f. Observe verification soil sampling and Opposed Crystal System (OCS)

analysis.

g. Observe gamma surveying at processing site and, if possible, alpha

surveying of any structures to remain.

 10. Monitoring Well Observations 

a. Check locations of existing wells. Verify that the field locations correspond

to the location depicted on site drawings. Verify that the well is properly and

permanently labeled.

b. Verify that existing well locations are adequately marked with flagging or

some other identification placard to avoid inadvertent destruction by heavy

equipment.
Issue Date: 10/05/01 A-5 2620, APPENDIX A

c. Verify that the outer protective casing, padlock, concrete pad, and other

surface expressions are in good repair. Verify that well caps are secure to

minimize inadvertent dust invasion inside the well casing. Note any

irregularities, such as bent or damaged casing, animal burrows or erosion

around the well, and proximity of equipment tracks.

d. Check the locations of previously abandoned monitoring wells. Verify the

field locations with respect to the site drawings. Verify that the surface

expression has been completed in accordance with the Monitoring Well

Abandonment Specification. Note any irregularities, such as concrete

shrinkage, surface depressions, or exposed well pipe.

 11. Ground-Water Sampling Observations

a. Observe any monitoring well sampling or well measurements that may be

occurring. Verify that the equipment is handled in accordance with the

project specifications. Verify that equipment use and decontamination

procedures have been followed in accordance with appropriate standard

operating procedures of the Albuquerque Operations Manual for the Uranium

Mill Tailings Radiation Action (UMTRA) Project.

b. Verify that calibrations have been performed and documented on equipment

used to make field measurements.

c. Verify that accurate and legible records are maintained during the field

sampling, including chain-of-custody documentation. Sampling information

should be recorded on the DOE or contractor forms identified in the Quality

Control (QC) project documents and in sufficient detail to support later quality

assurance reviews. Verify that samples are collected, handled, and stored

in accordance with procedures identified in the QC plan.

d. Verify that potentially contaminated ground water removed during well

purging and sampling is handled in accordance with procedures identified in

the Albuquerque Operations Manual for the UMTRA Project.

The reviewer may not be able to directly observe all facets of the activities identified above.

However, direct observation of activities should be made in accordance with the particular

On-Site Construction Review Plan (OCRP) prepared prior to the review. Activities which

should be observed include the Key Construction Milestones identified in the attached

Table I, as well as major construction activities which are unique to the site. Such unique

activities may include slurry wall construction, bentonite amendments to radon barriers,

ground modification, monitoring well activities, or other phases of work identified in the

OCRP. Observation of some field testing should be made at all site reviews. In some

cases, it will be necessary to observe a completed activity rather than work in progress.

The intent of the review is to determine whether the activities and/or the end product meet

the requirements of the RAP.

Additionally, during work observation, informal interviews with DOE and contractor

inspection personnel should be randomly conducted to determine how well employees

know their work activity. The reviewer should ascertain whether a sufficient number of
2620, APPENDIX A A-6 Issue Date: 10/05/01

adequately qualified inspection personnel are at the site, commensurate with the work in

progress, and whether they are adequately performing their assigned duties through the

established organizational structure. A determination of contractor personnel qualifications

should be based on the contractor's published position description/job standards which is

available at the project office.

D. RECORDS REVIEW

The reviewer should examine selected documentation maintained on site to ascertain the

following:

 1. Records confirm that required material characteristics and other specification

requirements were met.

2. Records confirm that specified materials were installed in accordance with

specifications.

3. Records indicate that adequate corrective action is being taken following nonconformance/deviation occurrences.

4. Records confirm that the required inspections and testing were performed

adequately and at required frequencies.

5. Records establish that DOE inspection personnel are adequately qualified for their

assigned duties and responsibilities.

6. Records confirm that any field measurements of parameters for radon barrier

analysis that deviate from those presented in the RAP are incorporated into a new

analysis before the radon barrier is completed.

E. DOCUMENTATION

All aspects of the construction observed in accordance with the above-recommended

review activities should be documented in the On-Site Construction Review Report

(OCRR), an example of which is attached as Appendix C. The report should address each

identified aspect as being satisfactory, being unresolved and requiring resolution, or being

in conflict with the RAP, construction specification, or RAIP requirements and needing

correction. The Review Team Leader identified in the OCRR will have the responsibility

of following up the corrective action and shall prepare written documentation to that effect.

The Review Team Leader's supervisor shall concur with the report and follow-up

documentation.
Issue Date: 10/05/01 A-7 2620, APPENDIX A

Table 1

KEY CONSTRUCTION MILESTONES

a. Early Stages of Remedial Action:

 1. Test Fill Construction *

 2. Foundation and Subgrade Preparation *

 3. Placement of Capillary Break *

 4. Placement of Seepage Barrier/Liner *

 5. Placement of Contaminated Materials **

b. Soil Cover:

 1. Placement of Radon Barrier **

 2. Placement of Frost Protection Layer *

c. Placement of Bedding Layer(s) and Rock Cover ***

d. Completion of Remedial Action (Closeout) ***

________

* May or may not apply to a particular site depending on site-specific design.

 ** Will apply to all remedial action sites.

 *** Will apply to nearly all sites (vegetative cover may be proposed for 1 or 2 sites).

END
Issue Date: 10/05/01 B-1 2620, APPENDIX B

APPENDIX B

ON-SITE CONSTRUCTION REVIEW PLAN

FALLS CITY UMTRA PROJECT INSPECTION, 12-9-92

CONTACT: Woody Woodworth, DOE Site Manager

FTS 8-505-845-5725

DATE: December 9, 1992

TEAM MEMBERS & Daniel Rom, Geotechnical Engineer

ASSIGNMENTS: Michael Layton, Groundwater Hydrogeology

PURPOSE: Routine Construction Review

SCOPE:

 1. Introductions

 2. Brief safety indoctrination, if required

 3. Observe material placement and testing

 4. Observe area of wet slimes exposed on the face of the disposal cell

 5. Observe area of naturally-occurring radioactive "red material"

 6. Observe dust control procedures

 7. Review settlement behavior of the embankment

 8. Observe construction activities at Pile #3

 9. Review written records

10. Conduct exit meeting

NOTE: There are no formal open issues to be resolved; however, the material

placement procedures in the area of exposed slimes will be addressed.

REVIEW SCHEDULE AND ROUTINE:

Pre-Site Meeting: December 9, 1992 - 7:30 a.m.

M. Layton & D. Rom

Entrance Meeting: December 9, 1992 - 9:30 a.m.

Exit Meeting: December 9, 1992 - 4:00 p.m.

Normal Site Hours: Assumed 7:00 a.m. to 4:30 p.m.

Motel: Holiday Inn, Airport - M. Layton

Marriott Courtyard - D. Rom
2620, APPENDIX B B-2 Issue Date: 10/05/01

Reservation # N/A

Government Rate $61.00

Signature: _________________________ Date: ______________

 Team Leader/Inspector

Approval: _________________________ Date: ______________

Section Leader
Issue Date: 10/05/01 C-1 2620, APPENDIX C

APPENDIX C

On-Site Construction Review Report

Facility Name: Falls City

UMTRA Project Site

Falls City, Texas

Review Conducted: December 9, 1992

NRC Personnel: Daniel Rom (Geotechnical Engineer)

Michael Layton (Hydrogeologist)

Review Summary:

Area Reviewed: In the morning, the tailings embankment, including piles 1, 2, and

7 (Parcel A) were reviewed. Next, pile 5 and the naturallyoccurring radioactive soils were seen, and the waste water

retention basin was viewed. The road crossing and right-of-way

to Parcel B, and Pile number 3 were observed in the afternoon.

Details:

1. Persons Contacted:

 Paul Mann (DOE)

Woody Woodworth (DOE)

Wei Lin (MK-ES)

Leroy Fields (MK-F)

Terry Stanford (MK-F)

Rick Sima (MK-F)

David Franco (MK-F)

Steve McQuarry (MK-F)

Bob Staub (MK-F)

Bob Tews (MK-F)

Larry Parker (Chem-Nuclear)

Peter Waggitt (visitor)

2. Equipment Operating:

2-245 Trackhoes

1-D7 Dozer

1-D7 Widetrack

3-D9 Dozers

1-16g Grader

1-14 grader
2620, APPENDIX C C-2 Issue Date: 10/05/01

3-Case Tractors w/disc

1-825 Roller

1-Cat smooth roller

1-8000 Water Truck

2-657 Scrapers

3. Site Review: 

The following discussion correlates to the scope of the review, as presented in the

attached On-site Construction Review Plan (OCRP):

Pre-Meeting (OCRP Items 1 and 2)

The NRC representatives arrived at the site office at 9:15 am. Introductions were

made shortly afterwards when the DOE staff arrived. Mr. Peter Waggitt of the Office

of the Supervising Scientist for the Alligator Rivers Region, Northern Territories,

Australia, also attended as a visitor. Mr. Waggitt was traveling with Mr. Woodworth,

and we were advised that he would join us on the review as an observer.

 

A safety presentation was given to Messrs. D. Rom, M. Layton, and P. Waggitt by S.

McQuarry, R. Sima, D. Franco, and R. Staub. The safety introduction included verbal,

written, and video presentations. Following the safety presentation, MK-F provided

yellow fabric coveralls, hard hats, and heavy-duty rubber overboots to all review team

members for their use while on site. We were further advised to stay with our escort

at all times.

Since the group was to take a walking tour of the site, a formal status report was not

given at the office. Instead, the group was advised of job progress as we walked to

the disposal cell from the office.

Material Placement and Testing (OCRP Item 3)

Routine placement of tailings was not underway at the time of the review. However,

the reviewers were able to observe unique fill placement operations on the northeast

side slopes of the cell. This area consisted of unstable wet slimes which were

exposed upon cutting the pile back from the road. The non-routine stabilization

methods were being prescribed by MK-ES to handle the difficult fill placement

conditions created by the wet materials. The wet slimes were being covered first with

a geotextile. A one-foot lift of drier contaminated soil was placed above the geotextile.

Four passes of heavy equipment were reportedly conducted prior to checking density.

Additional discussion and conclusions on the operations in the wet slimes area are

presented in the following section. 

The reviewers observed in-place density testing on the northeast edge of the

stabilized embankment. After clearing a test area with a loader, the technician used

a sand-cone to check soil density. The sand-cone density test we observed was
Issue Date: 10/05/01 C-3 2620, APPENDIX C

generally performed with care; however, the base plate did not appear to be level as

per ASTM requirements. Instead, the plate was more nearly parallel to the sideslope.

NRC staff notes that performance of the sand-cone density test with the base plate

on a sloping surface can result in the sand not properly filling the test hole. MK

personnel were advised to review the appropriate paragraphs of ASTM D-1556 testing

procedure for details on sand-cone density testing on a sloping surface.

Wet Slimes Area (OCRP Item 4)

In conjunction with the material placement and testing described above, the reviewers

observed shaping operations on the edge of the cell near pile number 2. Concurrently

we viewed exposed seeping tailings on the edge of the cell. The seepage condition

was recorded on video. The review team was informed that construction stabilization

of the seepage zone was by geotextile and bridging as previously described. The

stabilization operations were observed, and it appeared that the prescribed

combination of geotextile application and bridging effectively stabilized the face of the

slope such that equipment could operate thereon.

On the far (southwest) face of the embankment, additional tailings seepage zones

were observed and recorded. No construction was occurring in this seepage zone;

however, NRC staff indicated that stabilization might be more difficult on this face due

to the severity of the observed seepage and sloughing.

NRC staff has two concerns regarding the seepage areas described above. First,

DOE should examine the impacts on slope stability due to the placement of a

geotextile and bridge lifts of tailings. If a potential shear plane is being incorporated,

then slope stability factors of safety may be less than those presented in the RAP.

Special construction methods being used in these areas are also not found in the

RAP. Secondly, the long-term effects of seepage need to be addressed. If a seepage

situation similar to that at Durango is expected to occur, then consideration of postconstruction control should be provided. DOE needs to address these two concerns

in a PID. 

Naturally-Occurring Radioactive Materials (OCRP Item 5)

The reviewers subsequently viewed pile number 5 and the naturally- occurring

radioactive soils. Although these materials are not mill tailings, their measured activity

exceeds the standards for land cleanup of residual radioactive materials. Mr. Larry

Parker provided insight regarding the nature, occurrence, and disposition of the

naturally-occurring in-situ radioactive soils. DOE initially excavated materials which

were not mill tailings for cell placement. When it became apparent that the radioactive

soils were not tailings, characterization was performed to better establish their nature

and extent. Based on this characterization, DOE plans to leave in-place non-tailings

radioactive soils provided that post-construction radon emissions can be maintained

within accepted levels.

Dust Control (OCRP Item 6)
2620, APPENDIX C C-4 Issue Date: 10/05/01

Due to rainy weather the previous day, construction equipment was not operating on

the morning of the review. Dust suppression was not in progress due to the wet

subgrade conditions and lack of vehicular activity. DOE indicated that they had not

received any complaints from local residents regarding dust control.

Settlement Behavior (OCRP Item 7)

Following the fill placement and testing observations, the review team crossed the

main embankment and viewed materials which were previously placed. A line of four

settlement monitoring points was observed from the surface. It was reported that the

monitors were all operable and that no construction disturbance incidents had

occurred. Wei Lin provided the most recent settlement data to the NRC reviewers.

To date, settlement has been less than projected amounts. The shapes of the

measured settlement curves were generally parallel to those of the projected curves.

We understand that DOE will continue to review the embankment settlement behavior

and to refine the settlement model used in the RAP.

The NRC staff is concerned that recorded settlement may not be indicative of the

worst case, contrary to what was assumed in selecting the test area presented in the

RAP. The exposed slimes at the edges of the cell are saturated to the point that

excess moisture is being squeezed from the pores. DOE needs to address the slimes

consolidation issue to see if the measured settlement within the cell is representative

of that which is likely to occur within the saturated slimes at the edges of the cell.

Additional Observations in Parcel A

While atop the northwestern corner of the tailings pile, the review team observed the

topography and land use of the area between the disposal cell and property belonging

to Mr. Jerry Dzuik, located north of the site. During the PEIS Scoping Meeting at Falls

City on the previous day, Mr. Dzuik described a potential soil and groundwater

contamination incident that allegedly occurred on his property in the 1970's when the

mill was still operating. Additional information regarding this reported incident will be

requested from DOE at a later date.

Before returning to the Project Office, the review team observed operations at the

waste water retention basin. The basin was essentially empty, and crews were

physically removing small amounts of water which apparently accumulated during

yesterday's rain. Water removal was necessary since the crews were still completing

inspection of seams and repairs in the synthetic liner.

At about 1:30 pm soil conditions were sufficiently dry that earthmoving equipment was

able to operate. In conjunction with the startup, dust suppression activities were

begun. The walking tour of Parcel A was completed, and the team adjourned for

lunch. On exit from the controlled zone it was detected that the NRC video camera

needed to be left on site for decontamination. For this reason, the reviewers were

unable to take a video record of the Parcel B tour in the afternoon.

Parcel B/Pile 3 Observations (OCRP Item 8)
Issue Date: 10/05/01 C-5 2620, APPENDIX C

In the afternoon the reviewers conducted a driving tour of Parcel B. At the controlled

road crossing, a thick tarpaulin was placed across the pavement to collect

contaminated soil from the vehicle. We were informed that the right-of-way to Parcel

B was also the alignment for the slurry line from the days of mill operation. We were

also informed that the slurry line had on occasion broken, and that the area was

contaminated by wind-blown material. The right-of-way was fenced off, and the

Contractor had provided a drinking water system for livestock on the adjacent parcels.

No construction activity of consequence was occurring at Parcel B. Brush had been

cleared and the haul road right-of-way was being surveyed. MK and DOE

representatives discussed the proposed work for pile 3. Concerns expressed by

adjacent landowners, regarding the crossing of a public road, livestock on adjoining

parcels, and groundwater were being addressed through DOE's public relations

efforts.

4. Records Review:

After the tours of Parcels A and B, NRC staff reviewed field and laboratory records

pertaining to soil placement. In addition to the test records, equipment calibrations

and personnel records were well-maintained. The review of density test, gradations,

and calibrations yielded no discrepancies with the RAP, and test frequency was in

accordance with the requirements of the RAIP. It was noted that Mr. Fields appeared

to maintain complete, legible, and up-to-date records as required.

It was determined that the earthwork specifications (Section 02200) being used on the

site were Revision 4. The most recent set of specifications submitted to our office was

Revision 2. DOE needs to verify that specification changes from revision 2 to revision

4 are not changes of significance which have yet to be reviewed and concurred in by

NRC in accordance with the NRC/DOE Memorandum of Understanding.

5. Exit Interview:

An exit interview was held and the review items were summarized. Concern was

noted regarding the slime zones exposed on the slope. Current construction practice

appears to be adequate with respect to short-term stabilization; however, additional

zones may be encountered and these might require more attention to control.

Four items requiring DOE's response are noted:

a. Slope stability behavior due to current geotextile and bridge lift placement

operations needs to be addressed.

b. Measured settlement versus potential settlement in saturated slime zones

requires attention.

c. A comparison of revisions 2 and 4 to the earthwork specifications needs to be

made to see if any significant differences not previously brought to NRC's

attention are applicable.
2620, APPENDIX C C-6 Issue Date: 10/05/01

d. Sand cone testing procedures on sloped fill should be reviewed.

END