June 1, 2007

Keith Lockie

NE-ID/ID-S 

FACILITY AND MATERIAL DISPOSITION

U.S. Department of Energy

Idaho Falls, ID 83401

SUBJECT: NUCLEAR REGULATORY COMMISSION ONSITE OBSERVATION REPORT

FOR THE IDAHO NATIONAL LABORATORY IDAHO NUCLEAR

TECHNOLOGY AND ENGINEERING CENTER TANK FARM FACILITY

Dear Mr. Lockie:

The enclosed document describes the U.S. Nuclear Regulatory Commission’s (NRC’s) onsite

observation activities on April 24-25, 2007, at the Idaho National Laboratory (INL), Idaho

Nuclear Technology and Engineering Center Tank Farm Facility (INTEC TFF). This onsite

observation was conducted in accordance with the Ronald Reagan National Defense

Authorization Act for Fiscal Year 2005 (NDAA), which requires NRC to monitor disposal actions

taken by the Department of Energy (DOE) for the purpose of assessing compliance with the

performance objectives set out in 10 CFR Part 61, Subpart C. The activities conducted during

the site visit were consistent with those described in the NRC’s monitoring plan, dated May 3,

2007, for INTEC TFF. 

NRC’s onsite observation at INL was primarily focused on two performance objectives, 10 CFR

61.41, protection of the general population from releases of radioactivity, and 10 CFR 61.43,

protection of individuals during operations, by observing DOE’s tank grouting operations and

verifying DOE’s radiation protection measures in its INTEC TFF tank closure operations. Since

the tank grouting operations will impact the long-term stability of the tank farm facility after its

closure, this observation also partially assessed the performance objective in 10 CFR 61.44,

stability of the disposal site after closure. Additional visits will be conducted in the future to

assess compliance with these and other performance objectives in 10 CFR Part 61, Subpart C. 

If you have any questions or need additional information regarding this report, please contact

Xiaosong Yin, project manager on my staff, at 301-415-7640

Sincerely,

/RA/

Scott Flanders, Deputy Director

Division of Waste Management

 and Environmental Protection

Office of Federal and State Materials

 and Environmental Management Programs

Enclosure: NRC Observation Report
June 1, 2007

Keith Lockie

NE-ID/ID-S 

FACILITY AND MATERIAL DISPOSITION

U.S. Department of Energy

Idaho Falls, ID 83401

SUBJECT: NUCLEAR REGULATORY COMMISSION ONSITE OBSERVATION REPORT FOR THE

IDAHO NATIONAL LABORATORY IDAHO NUCLEAR TECHNOLOGY AND

ENGINEERING CENTER TANK FARM FACILITY

Dear Mr. Lockie: 

The enclosed document describes the U.S. Nuclear Regulatory Commission’s (NRC’s) onsite observation

activities on April 24-25, 2007, at the Idaho National Laboratory (INL), Idaho Nuclear Technology and

Engineering Center Tank Farm Facility (INTEC TFF). This onsite observation was conducted in

accordance with the Ronald Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA),

which requires NRC to monitor disposal actions taken by the Department of Energy (DOE) for the purpose

of assessing compliance with the performance objectives set out in 10 CFR Part 61, Subpart C. The

activities conducted during the site visit were consistent with those described in the NRC’s monitoring

plan, dated May 3, 2007, for INTEC TFF. 

NRC’s onsite observation at INL was primarily focused on two performance objectives, 10 CFR 61.41,

protection of the general population from releases of radioactivity, and 10 CFR 61.43, protection of

individuals during operations, by observing DOE’s tank grouting operations and verifying DOE’s radiation

protection measures in its INTEC TFF tank closure operations. Since the tank grouting operations will

impact the long-term stability of the tank farm facility after its closure, this observation also partially

assessed the performance objective in 10 CFR 61.44, stability of the disposal site after closure. Additional

visits will be conducted in the future to assess compliance with these and other performance objectives in

10 CFR Part 61, Subpart C. 

If you have any questions or need additional information regarding this report, please contact Xiaosong

Yin, project manager on my staff, at 301-415-7640.

Sincerely,

/RA/

Scott Flanders, Deputy Director

Division of Waste Management

 and Environmental Protection

Office of Federal and State Materials

 and Environmental Management Programs

Enclosure: NRC Observation Report

DISTRIBUTION: EPAB r/f DMcIntyre (OPA) NJensen (OGC) TCombs (OCA)

ML071300222

OFC FSME/DWMEP FSME/DWMEP FSME/DWMEP FSME/DWMEP

NAME X.Yin C.McKenney R.Whited S.Flanders

DATE 5/ 30 /07 5 / 30 /07 5 / 30 /07 6 / 1 /07 

OFFICIAL RECORD COPY
3

IDAHO NATIONAL LABORATORY IDAHO NUCLEAR TECHNOLOGY AND ENGINEERING

CENTER TANK FARM FACILITY 

NRC ONSITE OBSERVATION REPORT

EXECUTIVE SUMMARY

NRC staff conducted its first onsite observation visit of the INTEC TFF on April 24 to 25, 2007.

This visit was intended to focus on two of the four performance objectives—10 CFR 61.41,

protection of the general population from releases of radioactivity, and 10 CFR 61.43, protection

of individuals during operations—by observing DOE tank grouting operations and verifying

DOE’s radiation protection measures for its INTEC TFF tank closure operations. Because the

tank grouting operations will impact the long-term stability of the TFF after its closure, this

observation also was intended to partially assess compliance with the performance objective in

10 CFR 61.44, stability of the disposal site after closure. This report provides a description of

NRC onsite observation activities and identifies NRC findings from the visit. 

Grout Formulation and Performance

NRC staff evaluated the implementation of the quality assurance program and reviewed the

records pertaining to tank grouting operations. NRC staff also observed and reviewed data

collected to assess consistency with assumption made in the waste determination. 

• The observation determined that the quality assurance program of DOE and its

contractor, CH2M-WG Idaho, LLC (CWI), is being implemented effectively. NRC staff

also determined CWI has a robust program for verifying that the grout components

conform to applicable ASTM standards and that the final grout formulations are

consistent with the design specifications assumed in the waste determination.

• NRC has requested additional information regarding (i) the qualifications required of

vendors to be on DOE’s “approved vendors” list and (ii) the minimum cure time between

grout pours. NRC staff also recommended that DOE provide documentation to

demonstrate that the high water to cement ratio used in grouting tanks WM-104, WM105, and WM-106 will not adversely impact the expected performance of the grout. 

• NRC recommended that DOE document deviations result from implementation and

evaluation with respect to assumptions made in its final waste determination and

performance assessment (PA) to assess the risk significance of these deviations. 

Radiation Protection Program

NRC staff interviewed DOE and its contractor’s radiation protection personnel, reviewed the

radiological control documents associated with TFF tank closure operations, and reviewed the

associated worker dose records.

• The observation determined that DOE has an adequate program for protecting its

personnel from radiation exposures during TFF tank closure operations. 
4

1.0 BACKGROUND

The National Defense Authorization Act for Fiscal Year 2005 (NDAA) authorizes the

DOE, in consultation with the NRC, to determine that certain radioactive waste related to

the reprocessing of spent nuclear fuel is not high-level waste, provided certain criteria

are met. The NDAA also requires NRC to monitor DOE disposal actions to assess

compliance with the performance objectives in 10 CFR Part 61, Subpart C. 

On September 7, 2005, DOE submitted a draft waste determination for residual waste 

stored in the INTEC TFF to demonstrate compliance with the NDAA criteria including

demonstration of compliance with the performance objectives in 10 CFR Part 61,

Subpart C. In its consultation role, the NRC staff reviewed the draft waste determination

and concluded that the NDAA criteria could be met for residual waste stored in the

INTEC TFF. NRC documented the results of its review in a technical evaluation report

(TER) issued in October 2006 (NRC, 2006). DOE issued a final waste determination

in November 2006 taking into consideration the findings documented in NRC’s TER. 

To carry out its monitoring responsibility under the NDAA, NRC plans to perform three

types of activities focusing on key monitoring areas (KMAs) identified in its monitoring

plan for the INTEC TFF (NRC, 2007): (i) technical reviews, (ii) onsite observations, and

(iii) data reviews. Technical reviews generally will focus on obtaining additional model

support for assumptions DOE made in its PA that are considered important to DOE's

compliance demonstration. Onsite observations generally will be performed to (i)

observe and review data collected to assess consistency with assumption made in the

waste determination (e.g., observation of waste sampling used to generate data on

residual waste inventories) or (ii) observe key disposal (or closure) activities related to

technical review areas (e.g., slag and other material storage, grout formulation and

preparation, and grout placements). Data reviews will supplement technical reviews

focusing on real-time monitoring data that may also indicate future system performance

or review of records or reports that can be used to directly assess compliance with

performance objectives. 

NRC’s April 2007 onsite observation at INL was focused primarily on two performance

objectives, 10 CFR 61.41, protection of the general population from releases of

radioactivity, and 10 CFR 61.43, protection of individuals during operations, by

observing DOE’s tank grouting operations and verifying DOE’s radiation protection

measures in its INTEC TFF tank closure operations. Because the tank grouting

operations will impact the long-term stability of the tank farm facility after its closure, this

observation also was to partially assess the performance objective in 10 CFR 61.44,

stability of the disposal site after closure. Additional visits will be conducted in the future

to assess the performance objective in 10 CFR 61.42, protection of individuals against

inadvertent intrusion, and to continue assessing DOE compliance with the other

performance objectives. 
5

2.0 NRC ONSITE OBSERVATION ACTIVITIES

2.1 Grout Formulation and Performance

2.1.1. Observation Scope

The observation of DOE tank grouting operations is related to KMA 2, “Grout

Formulation and Performance” identified in the NRC monitoring plan for the INTEC TFF 

(NRC, 2007). An objective of NRC monitoring activities related to KMA 2 is to ensure

that the final grout formulation used to stabilize the TFF waste is consistent with design

specifications assumed in the final waste determination [DOE Idaho Operations (DOEID), 2006], or that significant deviations from design specifications will not negatively

impact the expected performance of the grout. As stated in the NRC monitoring plan

(NRC, 2007), technical reviews and observations related to KMA 2 will be performed to

ensure that reducing conditions will be maintained in the grouted tank and the shortterm performance of the grouted vaults will be sufficient to mitigate the release of shortlived radionuclides from the disposal facility. The reducing capacity of the tank grout is

important in mitigating the release of Tc-99, whereas the short-term performance of the

grouted vault is important in mitigating the release from the contaminated sand pads of

short-lived radionuclides, such as Sr-90, that could potentially dominate the predicted

doses from the TFF within the first few hundred years (NRC, 2006).

2.1.2 Observation Results

NRC staff had intended to observe ongoing tank operations at the TFF. However,

several days prior to the scheduled NRC visit, operational problems were encountered

by the DOE contractor, CWI, during grouting of tank WM-182. Apparently, during the

first day of engineered placement grout pours, adequate spacing was not maintained

between the bottom of the two articulating tank grout arms and the top of the grout

placements. Both grout arms were found the next day to be encased in the hardened

grout at the bottom of the tank. The steam jet also was found to be buried in several

inches of hardened grout after one of the grout pours flowed closer to the jet suction

than anticipated. DOE-ID suspended grouting operations to allow CWI to fix the

problem. Thus, NRC staff was unable to observe any tank grouting operation and its

activities were limited to a tour of the grout batch plant, review of records, and interviews

with CWI staff. 

NRC staff evaluated the implementation of the quality assurance program pertaining to

tank grouting in relation to the (i) “Farm Facility Grout Design Mix and Quality

Assurance/Quality Control Testing” (DOE-ID, 2006; Appendix C) and (ii) SPC-763,

“INTEC Grout and CLSM Supply Project” (CWI, 2007). The staff utilized information in

these documents to select a sample of project records to review and CWI personnel to

interview. Another document the staff reviewed was the “Compliance and Monitoring

Plan for Performing Grouting at the INTEC Tank Farm Facility Closure Project” (CWI,

2007b). This document identified activities to be conducted by CWI, including

verification of grout formulas and performance of quality assurance testing, in order to

ensure the correct placement of grout in the TFF tanks and ancillary equipment

according to closure requirements and design specifications.
6

NRC staff reviewed CWI records and verified that the received grout materials had

certified chemical and physical test reports that are based on ASTM standards (e.g.,

ASTM C 989 for blast furnace slag, ASTM C 618-03 for fly ash, and ASTM C 150 for

Portland cement). A review of representative test reports indicated the received

materials conformed to the standards. NRC staff verified from CWI records that the

engineered grout pour mix conforms to the specific requirements in the waste

determination and in SPC-763. CWI staff explained that preparation of grout mixtures at

the batch plant is computer controlled and that for each batch (or truckload) of grout, a

ticket is prepared documenting the mix description, volume of material in the mix,

percent moisture of the sand, and water to cement ratio. NRC staff examined

representative batch tickets and verified that the measured weights of the engineered

grout pour components (Portland cement, fly ash, slag, sand, water, and admixture)

reported in the tickets were within 1 percent of the grout mix design specifications. 

The water to cement ratios recorded in the batch tickets for tank WM-182 were found to

be within the maximum limit of 0.65 specified in SPC-763. However, the batch tickets

for the grouting performed in 2006 on three of the four small (30,000 gal) tanks (WM104, WM-105, and WM-106) showed water to cement ratios in the range 0.92 to 0.94.

These values exceeded the SPC-763 specification and are greater than the ratio (0.63)

for the fourth small tank (WM-103), which was grouted in March 2007. SPC-763 was

prepared after grouting of the three small tanks had been completed. The water to

cement ratios used for the first three tanks are less than 1.0, the maximum value

calculated from the formulation for controlled low-strength grout specified in Appendix C

of the waste determination document (DOE-ID, 2006). However, the correlation between

water to cement ratio and permeability presented in Thorne (2007; Figure 2) indicates

the resulting permeability of grout with a water to cement ratio of 0.90 would be about

2 × 10–10 m/s, two orders of magnitude higher than for grout with a water to cement ratio

of 0.65 and three orders of magnitude higher than the initial grout permeability assumed

in the PA degradation analysis. The residual radionuclide inventory in the three small

tanks is small and the higher permeability of the grout likely would not lead to a

significant increase in dose to the general population. NRC recommended that DOE

document deviations with respect to assumptions made in its final waste determination

and PA and assess the risk significance of these deviations. DOE is considering how

best to document these deviations as disposal actions progress. 

NRC staff also verified that the measured sulfide sulfur content of the blast furnace slag

supplied by the vendor is consistent with SPC-763. The amount of sulfide in the slag is

important because it imposes on the grout a reducing condition that helps mitigate the

release of Tc-99. The measured sulfide sulfur content of the slag listed in representative

chemical test reports was found to be greater than the specified 0.7 weight percent

minimum.

NRC staff verified the grout mixture that arrives at the TFF from the batch plant is

sampled and tested by CWI to ensure it meets the grout composition requirements. A

logbook documenting grout placement activities is maintained by CWI staff and includes

a copy of the batch ticket and a grout placement log on which the result of the slump

test (ASTM C 143/C 143M), as well as any upset condition, is recorded. The logbook

also includes an Inspection Planning Package, which lists specific inspections required
7

to be performed for each TFF closure activity and has a summary of inspection and test

results. NRC verified from selected grout placement logs that grout mixtures that do not

meet the specifications are sent for disposal at a landfill. 

During its visit to the grout batch plant facility, NRC staff observed the weathertight silos for storage of the slag and cementitious materials. The silos appeared

to be adequate for preventing precipitation from contacting the grout materials to

minimize the degradation in the quality and chemical reactivity of the slag and

Portland cement. 

2.1.3 Conclusions and Followup Actions

The NRC staff determined that the DOE and CWI quality assurance program pertaining

to tank grouting is being implemented effectively. However, additional site visits will be

conducted to observe tank grouting operations. DOE-ID should consider developing

additional controls or procedures based on lessons learned from the operational

problems encountered during the grouting of tank WM-182. 

CWI records indicate the grout components conform to ASTM standards and the grout

formulations are consistent with the design specifications assumed in the waste

determination. However, because DOE and CWI do not conduct independent sampling

and analysis of the grout materials but rely, instead, on test reports provided by the

vendor, NRC staff has requested information regarding the qualifications, e.g., quality

assurance program, of vendors on DOE’s approved vendor list.

NRC staff requested a copy of engineering calculations that CWI used as the basis for

using a minimum cure time of 30 minutes between grout pours. NRC staff also

recommends that DOE provide documentation regarding the risk significance of the

higher water to cement ratios—compared to that assumed in the PA supporting the

waste determination—of grout used to fill three of the four small tanks.

NRC staff plans to conduct additional site visits in the future to observe grouting of the

large tanks WM-180 through WM-186 and to followup on any remaining issues identified

above. 

2.2 Radiation Protection Program

2.2.1 Observation Scope

To verify that DOE’s radiation protection program is in place for its tank closure

operations to assess compliance with 10 CFR Part 61.43, protection of individuals

during operations, the onsite observation included (i) interviews with DOE and its

contractor’s radiation protection personnel; (ii) reviews of radiological control documents

associated with TFF tank closure operations, e.g., the Idaho Cleanup Project Radiation

Control Manual (CWI 2006a), and ALARA Program and Implementation (CWI 2006b);

and (iii) reviews of associated worker dose records. NRC staff toured the INTEC site to

verify the level of access control in general and TFF-specific access control. The onsite

tour also included observation of the operation of the Radiological Control Information
8

Management System (RCIMS), which controls individual radiological worker doses

specifically associated with TFF tank closure activities. 

2.2.2 Observation Results

DOE-ID contracted with CWI to provide radiological protection for site personnel during

TFF tank closure operations. The regulation that establishes DOE’s standards for

protection against ionizing radiation is 10 CFR 835, Occupational Radiation Protection. 

Other radiation protection requirements for TFF tank closure operations are the

applicable provisions of DOE Order 5400.5, Radiation Protection of the Public and the

Environment. DOE-ID is providing systematic oversight of the radiation protection

program of CWI, which includes daily communications on TFF tank closure operations,

quarterly program assessment, ALARA benchmark review, and annual input towards

CWI’s overall contract reviews. 

Through interviews with site radiation protection personnel, NRC staff determined that

CWI has adequate programmatic radiation protection measures. The radiological

control director, who reports directly to the CWI vice-president, has direct responsibility

for overall TFF tank closure radiological control operations. Because the Idaho cleanup

and tank closure project involves many simultaneous individual projects, all radiation

protection measures are project oriented. The radiation control manager on site reports

to the CWI radiological control director while providing supervision to lower level site

operational foremen and radiological control technicians and/or engineers. The 

operational foremen have the authority to stop an operation if unsafe radiological

conditions have been determined or suspected.

Radiation levels at the TFF are typically low when there are no tank waste removal or intank retrieval operations ongoing, and the TFF is posted as a radiation buffer area under

these conditions. However, the TFF is fenced with a limited access point and personnel

entering the TFF are required to have a personal radiation monitoring device and to

have undergone radiation worker training, in addition to other industrial worker

requirements. During tank grouting operations, all personnel entering the TFF are

required to have a radiation work permit that needs three levels of management

approval. ALARA review is required for all tank grouting activities. There are additional

controls for each tank inside the TFF, including control tents. When the tank cap is

open, the area is re-posted as a high radiation area and only specially trained personnel

with special personal protective equipment, e.g., respirators, are allowed to enter the

tents. A bioassay is conducted after each such operation.

Because all Idaho cleanup and tank closure operations are project oriented, a special

personal ED (Electronic Dosimeter) monitoring device is required for each person

conducting a specific project. While a TLD (Thermoluminescence Dosimeter) that is

exchanged every quarter provides a total personal radiological dose received over that

period, an ED can provide a specific dose associated with a specific activity, e.g., TFF

tank closure operation. Through interviews with radiation protection personnel and
9

observing the RCIMS operation, it was determined that the use of EDs can provide

accurate information on worker dose associated with TFF tank closure operations. 

A review of TFF operation personnel dose records for 2006 and the first quarter of 2007

indicated there were no personal overexposure or overdose incidents involving TFF tank

closure operations. The maximum dose received by a worker during the first quarter of

2007 was 37 mrem. There were no incidents involving personal contamination or loss of

control of radioactive material during TFF tank closure operations. 

Through interviews with radiation protection personnel, it was determined there are

adequate programs in place that provide radiation training for new and experienced

workers. NRC staff also found that there is an emergency program in place with an

adequate level of reporting and response procedures and adequate equipment to

provide the first level of emergency decontamination operations. 

2.2.3. Conclusions and Followup Actions

Through a review of the radiation protection program implemented by DOE-ID and CWI

at the INTEC TFF facility, interviews with radiation protection personnel, and a tour of

the facility, NRC staff determined that DOE-ID has an adequate radiation protection

program in place for TFF tank closure operations. No specific items were identified for

followup. NRC will continue monitoring activities related to radiation protection.
10

3.0 PARTICIPANTS

NRC Observation Team

Scott Flanders

Xiaosong Yin

Cynthia Barr

Roberto Pabalan

Idaho Department of Environmental Quality

Kathleen Trever

Bruce LaRue

Partial List of DOE Representatives

Keith Lockie, DOE-ID

Keith Quigley, CWI

Trent Harris, CWI

Jeff Long, CWI

Sandy Hyman, CWI

Keith Branter, CWI

Terry Hendricks, CWI

Rick Horn, DOE-ID
11

4.0 REFERENCES

CWI, “”Radiological Control manual, Chapter 3", PRD-183, Revision 8.Idaho Falls, Idaho:

CH2M-WG, LLC (CWI). February 2006a.

CWI, “ALARA program and implementation”, MCP-91, Revision 15. Idaho Falls, Idaho: CH2MWG, LLC (CWI). August 2006b.

CWI. “Specifications for INTEC Grout and CLSM Supply Project.” SPC-763, Revision 1. Idaho

Falls, Idaho: CH2M-WG, LLC (CWI). March 2007.

DOE-ID. DOE/NE–ID–11226, “Draft Section 3116 Determination Idaho Nuclear Technology

and Engineering Center Tank Farm Facility–Draft.” Rev. 0. Idaho Falls, Idaho: DOE Idaho. 

September 2005.

–––––. DOE/ID–11226, “Basis for Section 3116 Determination for the Idaho Nuclear

Technology and Engineering Center Tank Farm Facility.” Rev. 0. Idaho Falls, Idaho. DOE

Idaho. November 2006.

NRC. “U.S. Nuclear Regulatory Commission Technical Evaluation Report for the U.S.

Department of Energy Idaho National Laboratory Site Draft Section 3116 Waste Determination

for Idaho Nuclear Technology and Engineering Center Tank Farm Facility.” Washington, DC: 

NRC. 2006.

–––––. “U.S. Nuclear Regulatory Commission Plan for Monitoring Disposal Actions Taken by

the U.S. Department of Energy at the Idaho National Laboratory Idaho Nuclear Technology

and Engineering Center Tank Farm Facility in Accordance with the National Defense

Authorization Act for Fiscal Year 2005.” Washington, D.C.: U.S. Nuclear Regulatory

Commission. May 2007.

Thorne, D. “Evaluation of Grout Formulations for Tank Farm Facility Closure.” PEI-EDF-1033,

Revision 0. March 2007.