ML071700624

Quarterly Remedial Action Progress Report, First Quarter 2007

ML071700624
Person / Time
Site:	Salem
Issue date:	06/15/2007
From:	Suey G Public Service Enterprise Group
To:	Tuccillo K Office of Nuclear Reactor Regulation, State of NJ, Dept of Environmental Protection, Bureau of Nuclear Engineering
References
Download: ML071700624 (14)

Text

PSEG Nuclear LLC P.O. Box 236, Hancock Bridge, NJ 08038-0236 0 Pu CERTIFIED MAIL Nuclear LLC June 15, 2007 Karen Tuccillo Radiation Protection Programs Bureau of Nuclear Engineering New Jersey Department of Environmental Protection 33 Arctic Parkway Trenton, New Jersey 08625 QUARTERLY REMEDIAL ACTION PROGRESS REPORT, FIRST QUARTER 2007 PSEG NUCLEAR, LLC, SALEM GENERATING STATION

Dear Ms. Tuccillo:

PSEG Nuclear LLC (PSEG) has prepared this Quarterly Remedial Action Progress Report (RAPR) for the purpose of providing a summary of groundwater remediation activities conducted since the submission of the previous RAPR in February 2007 at the PSEG Nuclear, LLC, Salem Generating Station (Station). The Station is located on Artificial Island in Hancock's Bridge, Salem County, New Jersey.

Groundwater remediation activities are being conducted to address tritium detected in shallow groundwater adjacent to and south of the Salem Unit 1 Reactor Containment and Fuel Handling Building.

The release of tritium contaminated water to the environment ceased in February 2003 when the Salem Unit 1 telltale drains were cleared and the Spent Fuel Pool (SFP) water that had accumulated behind the liner was drained.

Following the liner draining activities, a regular program was instituted whereby the telltales drains are monitored for flow and the seismic gap is drained on a regular basis.

This program has been continually refined over the course of the investigation and remediation. Data related to the seismic gap were previously provided in the 2006 Third Quarter RAPR. The data demonstrated that no short lived gamma radioisotopes have been consistently detected in the gap since May 2004 when monitoring of the water in the seismic gap started, supporting this conclusion that the release has ceased. Other supporting data include decreasing tritium concentrations in groundWater just outside the seismic gap.

At present, it is estimated that the previous estimate of 2 to 5 Curies of tritium in the plume where it exists above the NJDEP Ground Water Quality Criteria (GWQC)has been reduced by approximately 0.4 Curies.

. The range is dependant on the amount of tritium drawn back through the seismic gap, the degree of variability in the tritium concentrations of the groundwater, and the amount of mass held in dead end pore space.

Project Background In April 2004, a Remedial Investigation Report (RIR) was submitted to the New Jersey Department of Environmental Protection Bureau of Nuclear Engineering (NJDEP-BNE) presenting the details and results of groundwater investigation activities that were conducted following the discovery of tritium in groundwater adjacent to Salem Unit 1.

The results of the remedial investigation indicated that the source of tritium detected in groundwater was the Spent Fuel Pool, the tritium release to the environment had been stopped, and that tritium had not migrated to the property boundary above the New GWQC for tritium.

The remedial investigation produced a comprehensive body, of knowledge that was used as the basis for developing a remedial action strategy designed to hydraulically contain the further migration of tritium in groundwater that had previously been released from the seismic gap, and to reduce the concentration of tritium in the shallow groundwater adjacent to Salem Unit 1.

In July 2004, a Remedial Action Work Plan (RAWP) was prepared and submitted to the NJDEP-BNE presenting the proposed remedial actions for achieving these objectives.

The RAWP, which proposed the operation of a groundwater extraction system, was approved by the NJDEP in November 2004. In April 2004, prior to the submittal of the RAWP, PSEG initiated a groundwater extraction pilot study designed to demonstrate the effectiveness of groundwater extraction for achieving the remedial objectives. The pilot study proved to be effective and a full-scale groundwater extraction system was subsequently installed.

The following sections present the details and results of activities conducted since the submittal of the February 2007 RAPR, document the progress of remedial actions conducted to date, and provide a discussion of upcoming activities projected for the next reporting period.

Continued Groundwater Monitoring The data indicate that significant decreases in groundwater tritium concentrations have been accomplished to date. Groundwater monitoring activities continued through this reporting period in accordance with the schedule provided to NJDEP-BNE.

These activities consisted of the periodic collection of groundwater samples from the 36 Station monitoring wells. The sampling program is designed to ensure representative data are collected that meet the objectives of the investigation and provide the information necessary to evaluate plume containment.

Groundwater samples are submitted to Salem Chemistry for analysis for tritium and gamma isotopes. Samples indicating tritium concentrations less than 20,000 picocuries per liter (pCi/L) are sent to Maplewood Testing Services for more refined analysis. The large volume of analytical data collected to date indicates that plant related gamma-emitting isotopes have not been detected in any groundwater samples collected during the groundwater investigation.

2

An update of analytical results for groundwater samples from the Station monitoring wells through March 2006 are on Figure 1. Historic analytical results were presented in the RIR and previous RAPRs. Included on Figure 1 are: panel 1) the extent of tritium in groundwater at the completion of the remedial investigation (Baseline Plume), which was completed in April 2004; panel 2) the extent of tritium in groundwater in December 2005 following eight months of the pilot groundwater remediation activities and one year of the full scale system remediation activities; and, panel 3) the current extent of tritium in groundwater. Based on a review of the three panels on Figure 1, it is apparent that the mass of tritium in groundwater has been significantly reduced by the remedial efforts completed to date.

Details regarding these activities are included in this report.

It should be noted that the tritium concentrations in all wells is currently below 100,000 pCi/I. This is consistent with the results from December 2006 providing a positive and consistent indication that the remediation program is successfully removing tritium from the Unit 1 yard area.

Specific details regarding the analytical results for the groundwater samples are presented in the following sections. The analytical results for the monitoring wells were evaluated based on the water-bearing zone in which the monitoring wells are screened.

The three primary water-bearing units being investigated beneath the Station are: 1) the Vincentown Formation; 2) the shallow, water-bearing unit within the limits of the cofferdam; and, 3) the shallow, water-bearing unit outside of the limits of the cofferdam.

Attachment A presents the planned monitoring schedule through August 2007.

Tritium Analytical Results for the Vincentown Formation Groundwater quality for wells screened in the Vincentown Formation, which consist of Well V, Well K, Well L, Well P, Well Q, and, Well CB are currently monitored on a semi-annual basis. Groundwater samples collected from these wells are analyzed for tritium and gamma-emitting isotopes. Analytical results of groundwater samples collected from Wells P and Q indicate concentrations of tritium below the laboratory detection limits.

Tritium has only been detected at a concentration above laboratory detection limits once (July 2004) in groundwater from Well L; however, the tritium concentration was well below GWQC. Based on the long term trend for this well, it is believed that the July 2004 data point was not indicative of actual tritium concentrations. Analytical results of groundwater samples collected from Well K have never indicated tritium concentrations greater than 1,170 pCi/L, approximately four years ago, and are currently in the lower portion of its range (<153 to 1,170). At the request of the NJDEP BNE, an additional monitoring well, Well CB, was installed in the vicinity of Well K to provide additional data for this substrate. Analytical results from groundwater samples collected from Well CB indicate that tritium concentrations in the Vincentown formation in this area are approximately 155 pCi/L. This is lower than the concentrations detected in recent groundwater samples from Wells K and V.

3

Well V continues to exhibit concentrations of tritium betweenz 181 and 400 pCi/L. The maximum concentration observed in samples collected from Well V was 402 pCi/L in September of 2004. Concentrations in Well V are currently below 200 pCi/L.

Analytical results of groundwater samples collectedfrom the monitoring wells screened in the Vincentown Formation continue to indicate that the release of water from the Spent Fuel Pool has not migrated below the shallow water-bearing unit.

Tritium Analytical Results for Wells Installed Within the Limits of the Cofferdam Wells screened in the shallow, water-bearing unit within the limits of the cofferdam consist of Well M, Well N, Well 0, Well R, Well AC, Well AE, Well Al, Well AM, Well AN, and Well AO.

Based upon their location relative to the Salem Unit 1 seismic gap, analytical results of groundwater samples collected from these wells have historically and do presently indicate the highest tritium concentrations in groundwater at the Station.

Historic tritium concentration data is presented on Figure 1. Analytical trends for wells screened within this unit exhibiting tritium concentrations above NJDEP GWQC continue to show generally decreasing trends. This provides an indication that extraction through the operation of the Unit-i seismic gap drain, and operation of the groundwater extraction system are successful in decreasing tritium concentrations within this unit.

Well AC is located directly southeast of the Salem Unit 1 seismic gap and has indicated tritium concentrations as high as 15,000,000 pCi/L. Analytical results of more recent groundwater samples collected from this well indicate tritium concentrations of approximately 28,400 pCi/L.

The decrease in tritium concentrations at Well AC is additional confirmation that the release of water from the SFP has been stopped and the operation of the seismic gap drain and the groundwater recovery system (discussed later in the report) are effectively reducing concentrations of tritium in groundwater and providing hydraulic control of the plume.

The increased concentration of tritium detected in Well AM during March 2006, believed to be caused by the movement of a localized portion of the tritium plume, has been successfully addressed, through the use of the mobile groundwater extraction unit.

following the tritium concentration peak observed in September 2006, analysis of subsequent samples indicated concentrations were generally decreasing. The present concentrations have decreased by nearly 2 orders of magnitude, and are presently in a range consistent with expectations for this area of the plume (20,000-30,000 pCi/L).

The slight increase in tritium concentrations observed at Well 0 peaked around 29,000 pCi/L in January 2007 and has subsequently declined to approximately 17,100 pCi/L.

This is consistent with trends observed over the past several winters.

4

Tritium concentrations in groundwater within the cofferdam zones have generally decreased by one order of magnitude or more. This is a positive indication that the selected remedial strategy is effectively removing mass from the areas of greatest concentration.

Tritium Analytical Results for Wells Installed Beyond the Limits of the Cofferdam The wells installed in the shallow, water-bearing unit beyond the limits of the cofferdam are Well S, Well T, Well U, Well W, Well Y, Well Z, Well AA, Well AB, Well AD, Well AF, Well AG (Shallow and Deep), Well AH (Shallow and Deep), Well AJ, Well AL, Well AP, Well AQ, Well AR, Well AS, and Well AT.

At the request of the NJDEP BNE, an additional monitoring well, Well CA, was installed in the vicinity of Well U. Analytical results from recent samples collected from Well CA indicate that the tritium concentrations in groundwater in this area are approximately 695 pCi/L, This is greater than the concentration observed in Well U. These wells are screened either just above the clay confining unit that separates the shallow water-bearing unit from the Vincentown Formation, or in the interval indicating the highest tritium concentrations found in the shallow water-bearing unit at each boring location outside the cofferdam at the time of the Supplemental Investigation completed in August 2003.

As discussed in previous RAPRs, increased concentrations of tritium were detected in Wells W and AP in 2005.

PSEG responded by activating the mobile groundwater extraction unit to spot remediate the area. Subsequently concentrations of tritium in groundwater at these well locations exhibited a generally downward trend in concentrations. Tritium concentrations in these wells are currently below the GWQC.

The tritium concentration trends for wells screened in the shallow, water-bearing unit indicate that the groundwater extraction system has demonstrated the ability to achieve the remedial action objectives (i.e., reduce the mass of tritium in groundwater, and maintain hydraulic control). The current distribution of tritium in groundwater (March 2007) is presented on Figure 1, along with the distribution of tritium prior to the initiation of the pilot study (March 2004) and in December 2005. As shown on Figure 1, the mass of tritium in groundwater has continued to decrease through the operation of the groundwater extraction pilot study system and operation of the full-scale system.

Groundwater Extraction In accordance with the RAWP, groundwater extraction activities completed to date consisted of the operation of the pilot-study from April 26, 2004 to February 11, 2005 and operation of the full scale groundwater recovery system (GRS) from February 16, 2005 to the present.

Full-Scale System Based on the results of the pilot study, a full-scale system GRS was designed and installed.

The objectives of the full-scale system are the following: 1) to maintain 5

hydraulic containment of the tritium plume; and, 2) to reduce tritium concentrations in, groundwater.

The present full-scale system consists of the extraction of groundwater from Wells AB, AD, AJ, AN, AO, AS, and AT. Well S is not currently operating and has not been in operation during 2006 or 2007 as a result of its low yield and resulting pump failures.

Groundwater extracted from the wells is processed in accordance with the Station's United States Nuclear Regulatory Commission (USNRC) license and plant procedures.

Mobile Groundwater Recovery Unit The mobile groundwater recovery unit has been used to spot remediate several wells over the past several years.

To date the unit has been successful at removing groundwater containing elevated concentrations of tritium.

Elevated concentrations have been remediated using the mobile unit at wells AP and AM. Going forward the mobile unit will continue to be used in response to increased concentrations of tritium detected in groundwater on an as needed basis.

Total System Effluent Data and Evaluation The full-scale GRS became operational on February 16, 2005. The system operated in various configurations as part of the shakedown process for approximately the first month. The full-scale system discharges continuously in accordance with the Station's USNRC permit allowing the full-scale system to be more effective and efficient than the pilot-scale system. As of March 3, 2007, the full-scale system has recovered greater than 14 million gallons of groundwater. This is equivalent to an average recovery rate of approximately 13.8 gallons per minute or greater than 19 times the recharge rate for the extraction area (calculated to be 0.7 gallons per minute, based upon an assumed percentage of annual precipitation).

Water-Level Data and Evaluation Water-level measurements from the extraction and select observation wells have been monitored to demonstrate that the full-scale groundwater extraction system has hydraulically contained the migration of tritium in groundwater.

To demonstrate this effectiveness, water levels are periodically collected and evaluated as was provided in the Q4 2006 RAPR submitted in February 2007. Ongoing groundwater level gauging indicates that the GRS system continues to control the flow of groundwater in the Salem Unit 1 yard area.

Initial comparison of water levels measured in Vincentown wells and shallow water bearing zone wells indicates that the vertical gradient relationship between the two zones is uncertain at present. A study will be conducted to evaluate the relationship of water levels between the Vincentown formation and the shallow water bearing unit in the area between Salem unit 2 and the nuclear services facilities building. The results of this study will be presented in a subsequent RAPR.

6

Cumulative Curies Removed The various groundwater recovery activities conducted to date have been successful in recovering tritium from groundwater at and downgradient of the Salem Unit 1 seismic gap.

Full-Scale System As shown on Figure 2, approximately 2.5 curies of tritium have been recovered from the operation of the full-scale GRS through March 31, 2007. Approximately 0.93 curies of tritium were removed by the pilot system. This figure summarizes the results of the groundwater remediation activities conducted using the well field which includes both the pilot study and the permanent system. As of March 31, 2007, greater than 2.5 curies had been removed by the well field. The effectiveness is emphasized by the decrease and stabilization of system effluent concentrations since the activation of the full scale system in February 2005.

System effluent concentrations are presently around 13,500 pCi/L. This indicates that the GRS has been successful in significantly decreasing the concentrations of tritium in the subsurface as discharge concentrations are now 12 percent of the peak concentration (109,000) discharged by the GRS in March 2005. The mass of tritium in the plume was recalculated in early 2006 to be in the 2 to 5 Curie range (depending on the amount of tritium drawn back through the seismic gap, the actual variability in discharge concentrations and the amount of tritium remaining in dead end pore spaces) at concentrations above the NJDEP GWQC.

Based upon the tritium removed since the last recalculation, the present estimate would indicate that the plume retains 1.4 to 4.4 Curies of tritium.

Therefore it remains a distinct possibility that the GRS tritium removal may achieve end criteria ahead of the previously communicated schedule. The ongoing data collection will provide additional data to confirm this preliminary conclusion later in 2007.

Other Remedial Actions In addition to the operation of the GRS, seismic gap drains in Salem Unit 1 and Unit 2 are being used to drain the water from these gaps recovering concentrations of residual tritium from the seismic gap. The following sections provide a brief overview of the seismic gap draining activities.

Operation of the Seismic Gap Drain The permanent drains installed in the Salem Unit 1 and 2 seismic gaps facilitate the periodic collection and characterization of groundwater accumulating in the seismic gaps. The operation of these gap drains creates an inward gradient towards the gaps facilitating the recovery of water from low accessibility areas. Figure 3 summarizes the results of the seismic gap draining activities. A comparison of Figure 1 and Figure 3 reveals the concentrations of tritium in the water recovered in the Unit 1 drain have been significantly higher than those detected in groundwater samples collected from 7

Well AC and Well AM located to the southeast and southwest of the seismic gap, respectively. The Unit I seismic gap drain is effectively removing residual Spent Fuel Pool water in the seismic gap, and is resulting in the reduction of tritium concentrations in groundwater adjacent to the seismic gap. As shown on Figure 3, greater than 4 curies of tritium had been recovered from the operation of the Unit l-seismic gap drain as of September 2005. Significant concentrations of tritium continue to be removed from the Unit I seismic gap. The concentration distribution of tritium at the gap drains will vary with the source of the water being drained, the amount of precipitation since the last draining, and the movement of the water within the lower reaches of the seismic gap.

During the winter, increased levels of tritium were detected in samples collected from the Unit 1 seismic gap drain. The concentrations began declining in early February and by late March had decreased significantly from the peak concentrations observed over the winter.

As of early March 2007, PSEG initiated a continuous draining of the seismic gap drains on both Salem units to evaluate the impact on measured tritium concentrations and any effect on local area tritium concentrations.

Most importantly, continuous draining provides a positive assurance of an inward gradient of groundwater to the seismic gap and assures that there is no further potential to discharge to the environment.

Concentrations of tritium from the seismic gap are shown on Figure 3, The concentration of tritium from the seismic gap is anticipated to decline with the continuous draining of the seismic gap.

Analytical results for water samples are collected from the Unit 2 seismic gap drain to provide data on radionuclide concentrations of constituents to assure that there is not an indication of constituents that would indicate a similar release occurred from the Unit 2 Spent Fuel Pool. Additionally, no plant related gamma emitting isotopes have been found in samples collected from the Unit 2 seismic gap drain.

As evidenced by the lack of short-lived gamma-emitting isotopes, samples collected from the Unit 1 gap drain do not indicate an ongoing or recent release of spent fuel pool water. Additionally the Unit 2 seismic gap drain water contains no plant gamma activity.

Water samples will be obtained from both gap drains on a periodic basis to evaluate the water that has accumulated in the respective seismic gaps and to provide a backup warning of a potential release of spent fuel pool water.

The primary method for determining the potential release of spent fuel pool water is the monitoring of the SFP tell-tale drains and seismic gap drains.

Upcoming Activities Activities projected for the Second Quarter of 2007 (April through June) include the following:

8

Refine the procedures and protocols - as necessary 'to adaptively manage the operation and sampling of the full scale groundwater extraction system; Continue to measure groundwater levels and evaluate flow and plume containment; Install pressure transducing data loggers in selected wells Continued monitoring wells groundwater sampling and analysis activities; and, Continued operation and evaluation of data obtained through the full-scale groundwater extraction system.

Continue to monitor continuous draining of seismic gap drains Reduction in reporting frequency, (to semi-annual) following the Q2 2007 report.

If you have any questions or comments regarding the contents of this report, please do not hesitate to contact me at (856) 339-5066.

Sincerely, Manager -

Salem Chemistry, Environmental, and Radwaste C

Ron Nimitz-NRC NRC - Salem Resident Inspector NRC - Document Room 9

BC:

Chris White H15 George Gellrich S05 Ben Neufeld S07 Edward Keating N33 Jeffrey Pantazes T17A Christopher McAuliffe T5C File#Groundwater EXTERNAL Peter Milionis, ARCADIS Bradley Pierce, ARCADIS Scott Potter, PhD., ARCADIS Christopher Sharpe, ARCADIS 10

THIS PAGE IS AN OVERSIZED DRAWING OR

FIGURE, THAT CAN BE VIEWED AT THE RECORD TITLED:

FIGURE 1 "GROUNDWATER TRITIUM RESULTS."

WITHIN THIS PACKAGE... OR BY SEARCHING USING THE D-01X

PSEG Nuclear, LLC Salem Generating Station - Unit I Tritium Recovered Through Well Field Operation i3.000 900,000 30 Tritium Removed Per Week I800,000 2.500 2.00-Tritium Concentration Per Week

!7700,000.

( *,

---Cumulative Tritium Removed 2

2.000 600,000 500,000 0.

0!

o 1.500 o

4, 400,000,.

E' E

1.000 300,000 E

200,000 =

1 0.500 I-o.ooo 100,000 0.000 0

Date Am PSEG NUCLEAR, LLC f"'" NP 7.0 a

SALEM GENERATING STATION P r woj e

e

[

tor D raw in D Ot P,.*

HISTORIC TRITIUM RECOVERED THROUGH 16_MA,_200 Task Manage"r 6 Terry Drive FLure C. SHARPE Suite 300 WELL FIELD OPERATION TedwteReview Newtown, Pa 18940 2

Tel: 267/685-1800 Fax: 267/685-1801 C. SHARPE www.arcadis-us.com HANCOCK'S BRIDGE, NEW JERSEY

M M

M M

M M

M M M

M M

M M M

M M M

M M PSEG Nuclear, LLC Salem Generating Station - Unit 1 Tritium Recovered Through Seismic Gap Drain Operation (I) 4)

0 E

0)

E Iu--

5.00 4.50 4.00 3.50 3.00 2.50 2.00 1.50 1.00 0.50 140,000,000 120,000,000 100,000,000 80,000,000 60,000,000 40,000,000 20,000,000 2

G 0

0.

0 E

4-p 0.00 N

M A n 1

0 Date R. G PSEG NUCLEAR, LLC NP 7.005 I GSALEM GENERATING STATION P. MILIONIS R,,0EIs HISTORIC TRITIUM RECOVERED THROUGH 16 May, 2007 TaSk Manger 6 Terry Dve S

MA C SH.ARPE Suite 300 SEISMIC GAP DRAIN OPERATION Newtown Pa 18940 3

I T ReeW Tel 267/685-1800 Fax 267/685-1801 SC.SHARPE www.arcadis-us.com HANCOCK'S BRIDGE, NEW JERSEY