ExxonMobilRefining & Supply Company3225 Gallows RoadFairfax, Virginia 22037

VIA OVERNIGHT MAIL

May 18, 2006 E* pnMobilRefining & Supply

Gary Janosko, Chief

Fuel Cycle Facilities BranchDivision of Fuel Cycle Safety and SafeguardsOffice of Nuclear Material Safety and SafeguardsU.S. Nuclear Regulatory CommissionWashington DC 20555

RE: License Amendment RequestDocket No. 40-8102License No. SUA-1139ExxonMobil Highland Facility

Dear Mr. Janosko:

Groundwater monitoring at the Highland facility is performed in accordance with LicenseCondition 33 A. A review of the monitoring data indicates that a significant reduction in thesampling program could be made without sacrificing information that might be gained in thefuture.

There are currently 25 wells listed in the license that are monitored quarterly for indicatorparameters and semi-annually for hazardous constituents. An evaluation of the data indicates thatmany of the wells could be eliminated from the program, the frequency of sampling reduced andsome of the constituents eliminated from some of the wells without impacting the objectives ofthe monitoring program. The location of the wells in the current license is shown on Figure 1.The most recent groundwater monitoring report is also attached for your convenience.

There are six wells (015, 117, 127, 148, 177 and 180) that are dry. They reflect the decreasinggroundwater mound around the reclaimed tailings impoundment. These wells should beeliminated from the license.

There are four wells that are up-gradient from the reclaimed tailings impoundment (wells 134,172, 174 and 182). Two of the wells (174 and 134) are very far from reclaimed tailings and waterfrom these areas flow to pit. The two remaining background wells (172 and 182) and the existingdata from wells 174 and 134 are adequate to define background conditions. It is thereforeproposed that the monitoring requirement for wells 174 and 134 be deleted. Water qualityparameters for key constituents for these wells are shown on Figures 2 through 4.

Wells 120, 179 and 183 are in the same general location and completed in the same formation(tailings dam sandstone, TDSS) as POC well 176. These wells do not provide any additional dataand can be eliminated from the monitoring program with no impact. Water quality parameters forkey constituents for these wells are shown on Figures 5 through 7.

An ExxonMobil Subsidiary

Gary Janosko, Nuclear Regulatory CommissionMay 18, 2006Page 2 of 2

Similarly, well 114 is in the same location and completed in the same formation (TDSS) as well175 and can be eliminated without impacting the monitoring program. Water quality parametersfor key constituents for these wells are shown on Figures 8 through 10.

The last five years of data have indicated that changes in water quality are very small and thechanges occur slowly. In addition, virtually all of the hazardous constituents in the non-POCwells are below detection and well below any standards. Table I presents the most recent waterquality results for the hazardous constituents. Therefore it is proposed that that the monitoringfrequency be changed to semi-annually for POC wells (125, 175, and 176) and officialbackground well (182). Samples from these wells would be analyzed for all of the currentconstituents. It is also proposed that the remaining 9 wells (112, 116, 128, 129, 171, 172, 173,178 and 181) be sampled annually for the short list of indicator parameters.

The existing license condition 33 A reads as follows:

Sample wells 015, 112, 114, 116, 117, 120, 125, 127, 128, 129, 134, 148, 171, 172, 173,174, 175, 176, 177, 178, 179, 180, 181, 182, and 183 on a quarterly frequency forchloride, nitrate, sodium, sulfate, pH, TDS and water level, and on a semi-annualfrequency for arsenic, cadmium, chromium, gross alpha, lead, nickel, radium-226 and228, selenium, thorium-230, and uranium.

The proposed license condition 33 A would read as follows:

Sample wells 125, 175, 176 and 182 on a semi-annual frequency for chloride, nitrate,sodium, sulfate, pH, TDS, water level, arsenic, cadmium, chromium, gross alpha, lead,nickel, radium-226 and 228, selenium, thorium-230, and uranium. Sample wells 112,116, 128, 129, 171, 172, 173, 178 and 181 on an annual frequency for chloride, nitrate,sodium, sulfate, pH, TDS and water level.

As indicated during a recent meeting, additional wells have been installed, and more are to beinstalled southeast of the tailings impoundment. After all of the wells are installed and analyticalresults are obtained, the results will be submitted along with a proposal which will include wells,if any, to be added to the required monitoring program.

We appreciate the Staff's prompt attention to this request. Please feel free to contact me at (703)846-3272 if you have any questions regarding this request.

Sincerely,

Dan E. BurnhamTechnical Consultant

cc: Lou Miller - MFGFile - Groundwater

Table I Selected Recent Water Quality Data, Non-POC Wells

Well No. Date As (mgfL) Cd (mg/L) Cr (mg/L) Pb (mg/L) Ni (mg/L) Ra226 (pCi/L) Ra228 (p0iL/) ý Se (mg/!) Th230 (pCI!L)112 15-Feb-05

MFG, Inc.consulting scientists and engineers

FIGURE 1MONITORING WELL LOCATIONS

Date: APRIL 2006

Project: 100548

File: NRC-SAMPLES.dwg

Uranium

-E

E

0.1000 -

0.0900-

0.0800

0.0700

0.0600

0.0500

0.0400

0.0300

0.0200 -

0.0100 -

0.000001-Jan-86

* 134-- 1172

174

X 182

27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96

Date

10-Sep-99 06-Jun-02 02-Mar-05

MFG, Inc.consulting scientists and engineers

FIGURE 2URANIUM IN WELLS 134, 172, 174 AND 182

Date: MAY 2006

Project: P:\180548\

File: MONIT AMEND.ppt

Sulfate

700

600

500

400

E

--- 134172

174

182300 n--

200--

100

0-01-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

MFG, Inc.consulting scientists and engineers

FIGURE 3SULFATE IN WELLS 134,172,174 AND 182

Date: MAY 2006

Project: P:\180548\

File: MONIT AMEND.ppt

Chloride

120

100

80

-J

E60

40 _

20 ___

001-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

MFG, Inc.consulting scientists and engineers

FIGURE 4CHLORIDE IN WELLS 134, 172, 174 AND 182

Date: MAY 2006

Project: P:\180548\

File: MONIT AMEND.ppt

Uranium

0.1400

0.1200

0.1000

0.0800

E-

E

120

179

183

X 1760.0600

0.0400 - -

0.0200 -

0.0000

01-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

KMFG, Inc.consulting scientists and engineers FIGURE 5URANIUM IN WELLS 120,179, 183 AND 176 Date: MAY 2006Project: P:\180548\File: MONIT AMEND.ppt

Sulfate

3000-

2500

2000

-JC 1500E

1000

500

001-Jan-86

120

---- 179183

176

27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

MFG, Inc.consulting scientists and engineers

FIGURE 6SULFATE IN WELLS 120,179, 183 AND 176

Date: MAY 2006

Project: P:\180548\

File: MONIT AMEND.ppt

Chloride

500-

450

400--

350--

300

-jd 250E

200

150

100-

50 --

0-01-Jan-86

4 120

179

183176

27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96

Date

10-Sep-99 06-Jun-02 02-Mar-05

MFG, Inc.consulting scientists and engineers

FIGURE 7CHLORIDE IN WELLS 120,179, 183 AND 176

Date: MAY 2006

Project: P:\1 80548\

File: MONIT AMEND.ppt

Uranium

0.0250

0.0200

0.0150

-J---- 1140)E ----- 1750.0100 1

0.0050 -

0.000001-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

Sulfate

8000

7000

6000

5000

=4000E

3000

2000

1000

114

175

01-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

Chloride

700

600

500

400

I-JE

-.-- 114175

300

200

100

001-Jan-86 27-Sep-88 24-Jun-91 20-Mar-94 14-Dec-96 10-Sep-99 06-Jun-02 02-Mar-05

Date

MFG, Inc.consulting scientists and engineers

FIGURE 10CHLORIDE IN WELLS 114 AND 175

Date: MAY 2006

Project: P:\180548\

File: MONIT AMEND.ppt