ML15030A163
| ML15030A163 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/22/2014 |
| From: | Kenny K, Milionis P, Palmer G ARCADIS U.S. |
| To: | Office of Nuclear Reactor Regulation, Public Service Enterprise Group |
| Shared Package | |
| ML15030A230 | List: |
| References | |
| NP000571.2014 | |
| Download: ML15030A163 (0) | |
Text
Imagine the result PSEG Nuclear, LLC Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey September 22, 2014
Remedial Action Progress Report First Quarter 2014 Kate M. Kenny Salem Generating Station Staff Engineer Hancocks Bridge, New Jersey Prepared for:
PSEG Nuclear, LLC Prepared by:
Glenn C. Palmer ARCADIS U.S., Inc.
Senior Scientist 640 Freedom Business Center Suite 310 King of Prussia Pennsylvania 19406 Tel 610 768 5813 Peter N. Milionis, PG Fax 610 768 5817 Project Manager Our Ref.:
NP000571.2014 Date:
September 22, 2014 This document is intended only for the use of the individual or entity for which it was prepared and may contain information that is privileged, confidential and exempt from disclosure under applicable law. Any dissemination, distribution or copying of this document is strictly prohibited.
Table of Contents
- 1. Introduction 1 1.1 Background 1 1.1.1 Salem Unit 1 Investigation 1 1.1.2 Salem Unit 2 Investigation 3 1.2 Groundwater Monitoring Program Objectives 4 1.3 Recent Activities 5 1.3.1 GRS Repair Activities 5 1.4 Report Purpose and Organization 6
- 2. Data Evaluation 7 2.1 Meteorological Data 7 2.2 Effluent Data 7 2.2.1 Salem Units 1 and 2 Gaseous Effluent 8 2.2.2 Hope Creek Gaseous Effluent 8 2.2.3 Liquid Effluent 8 2.3 Water-Level Measurements 9 2.4 Groundwater Sample Collection 9 2.4.1 Low-Flow Sampling 10 2.5 Mass Flux Estimation of Tritium to the Delaware River 11
- 3. Results 13 3.1 Meteorological Data 13 3.1.1 Precipitation 13 3.1.2 Wind 14 3.2 Effluent Data 15 3.2.1 Gaseous Effluent 15 3.2.2 Liquid Effluent 15 3.3 Groundwater Elevation 16 3.4 Groundwater Sampling 17
Table of Contents 3.4.1 Salem Unit 1 - Shallow Wells Installed Within the Limits of the Cofferdam 18 3.4.2 Salem Unit 2 - Shallow Wells Installed Within the Limits of the Cofferdam 21 3.4.3 Shallow Wells Installed Outside the Limits of the Cofferdam 23 3.4.4 Vincentown Formation Wells 25 3.5 Mass Flux Estimation of Tritium Reaching the Delaware River 27
- 4. Groundwater Extraction 28 4.1 Reporting Period Status 28
- 5. Seismic Gap Drain Operation 29 5.1 Salem Unit 1 29 5.2 Salem Unit 2 30
- 6. Summary 31 6.1 Historical Trends and Current Results 31 6.2 Future Actions 32
- 7. References 33 Tables Table 1 Well Construction Details Table 2 Sample Collection Schedule - First & Second Quarter 2014 Table 3 Effluent Data Tritium Activity Table 4 Groundwater Measurements and Elevations - First Quarter 2014 Table 5 Groundwater Analytical Results (1/22/2003 through 3/31/2014)
Table 6A Groundwater Tritium Analytical Results for Well AC Table 6B Groundwater Analytical Results for Well AC Table 7 Unit 1 Seismic Gap Drain Tritium Analytical Results Table 8 Unit 2 Seismic Gap Drain Tritium Analytical Results
Table of Contents Figures Figure 1 Site Location Map Figure 2 Station Layout Map Figure 3 Salem Generating Station Layout Map Figure 4 Station Shallow Groundwater Elevation Contours - February 2014 Figure 5 Salem Generating Station Hydrogeologic Cross Section A-A Figure 6 Salem Generating Station Hydrogeologic Cross Section B-B Figure 7 Salem Generating Station Hydrogeologic Cross Section C-C Figure 8 Salem Generating Station Hydrogeologic Cross Section D-D Figure 9 Salem Generating Station Hydrogeologic Cross Section E-E Figure 10 Precipitation Measurements Figure 11 Station Wind Summary - First Quarter 2014 Figure 12 Groundwater Tritium Results Figure 13 Tritium Isoconcentration Map - March 2014 Figure 14 Tritium Recovered Through Well Field Operation Figure 15 Unit 1 - Tritium Concentrations in Water Recovered Through Seismic Gap Drain Operation Figure 16 Unit 2 - Tritium Concentrations in Water Recovered Through Seismic Gap Drain Operation Appendices A Mass Flux Calculations
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 1. Introduction ARCADIS U.S., Inc. (ARCADIS) prepared this Remedial Action Progress Report, First Quarter 2014 (RAPR) to summarize the groundwater remediation activities performed during first quarter 2014 at the PSEG Nuclear, LLC (PSEG), Salem Generating Station (SGS). The SGS and the Hope Creek Generating Station (HCGS) (collectively, the Station) are located on Artificial Island in Hancocks Bridge, Salem County, New Jersey (Figure 1). The Station and the SGS layout are depicted on Figures 2 and 3, respectively.
1.1 Background
The following sections describe investigations that occurred at the SGS Unit 1 and Unit 2.
1.1.1 Salem Unit 1 Investigation On September 18, 2002, the SGS Radiation Protection reported measuring low-level radioactivity on the shoes of several technicians. An initial investigation led to the discovery of a radioactively-contaminated calcium-like substance adhering to the west wall in the 78-foot Mechanical Penetration Room of the SGS Unit 1 Auxiliary Building. The buildup of calcium-like deposits, later determined to be crystallized boric acid, was removed and an active seep of water into the 78-foot Mechanical Penetration Room was observed. Further investigation revealed a second leak at the 92-foot elevation of the SGS Unit 1 Spent Fuel Pool (SFP) cooling line. As presented in the 2003 Remedial Investigation Work Plan (RIWP; ARCADIS 2003), PSEG collected samples from various locations. Results for these samples indicated that the water from both leaks had characteristics of the SFP water and that a possible leak from the SFP had occurred. Starting on December 11, 2002, PSEG collected a series of characterization samples from the water accumulating in the telltale drains. The telltale drains are a leak monitoring, collection, and drainage mechanism specifically designed to collect leakage that may accumulate behind the stainless steel liner of the SFP and Refueling Canal.
Analytical results collected indicated that the likely source of water in the SFP telltale drains was the SFP, while the source of water in the Refueling Canal telltale drains indicated a possible mixing with groundwater. On January 31, 2003, a fiber optic examination of the telltale drains indicated a blockage of boric acid crystals in the No. 4 and No. 5 drains beneath the welds in the stainless steel liner of the SFP. To establish FINAL_1Q2014 RAPR_9.22.2014.doc 1
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey hydraulic equilibrium with the water level in the SFP, the flow of water from the leak in the SFP liner accumulated between the liner plates and the concrete structure. The accumulated water migrated along paths of least resistance to the wall at the 78-foot elevation in the Mechanical Penetration Room, and through the penetration where the SFP cooling return lines intersect the wall at the 92-foot elevation.
Further investigation indicated that water from the SFP had migrated to the styrofoam-filled seismic gap located between the SGS Unit 1 Fuel Handling Building (FHB) and the Auxiliary Building. Therefore, remedial investigation (RI) activities were initiated to determine if the SFP water in the seismic gap had migrated beyond the limits of the engineered features of the building and into the environment (i.e., soil and groundwater in contact with the seismic gap). As detailed in the Remedial Investigation Report (RIR; ARCADIS 2004a) eight groundwater monitoring wells (wells K through R) were installed in January and February 2003 adjacent to and around the perimeter of the FHB. Analytical results of groundwater samples collected from these monitoring wells indicated that a release of water occurred from the SFP. The groundwater analytical data collected from the monitoring well network were used to delineate an area of groundwater in the shallow, water-bearing unit that contains elevated concentrations of tritium. Monitoring well construction details are presented in Table 1.
Based on the results of the RI, a remedial strategy was developed to hydraulically limit further migration and reduce the concentration of tritium remaining in groundwater adjacent to the SGS Unit 1. In April 2004, PSEG initiated a pilot study designed to demonstrate the effectiveness of groundwater extraction for achieving remedial objectives. The pilot study proved to be effective, and in July 2004, a Remedial Action Work Plan (RAWP; ARCADIS 2004b) proposing the operation of a full-scale groundwater remediation system (GRS) was submitted to the New Jersey Department of Environmental Protection (NJDEP) Bureau of Nuclear Engineering (BNE). The RAWP (ARCADIS 2004b) was approved by the NJDEP BNE in November 2004 and a full-scale GRS was subsequently installed. Operation of the GRS provides control over the flow of groundwater in the shallow, water bearing unit maintaining the tritium plume to the on-site area, while reducing the remaining mass of tritiated groundwater.
The source of the release of tritium-contaminated water to the environment was remedied in February 2003 when the Salem Unit 1 telltale drains were cleared and the SFP water that had accumulated behind the liner was drained. Routine maintenance of the SFP telltale drains has reduced the accumulation of standing water within the telltale drain system.
FINAL_1Q2014 RAPR_9.22.2014.doc 2
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey In April 2005, weekly draining of the SGS Unit 1 seismic gap was initiated to ensure that the flow of water entering the seismic gap was directed toward the interior of the building for treatment, rather than outward toward the environment. A program to continuously drain the SGS Unit 1 seismic gap was initiated in February 2007 and has continued to date.
Since the initial RI, the monitoring well network has been supplemented with additional monitoring wells outside the area of the baseline tritium plume to understand the presence of tritium in groundwater throughout the Station. In addition, PSEG monitors groundwater quality in the deeper underlying Vincentown Formation and shallow groundwater near the SGS.
1.1.2 Salem Unit 2 Investigation On April 6, 2010, PSEGs Chemistry group collected a water sample from Salem Unit 2 catch basin CB 18 following a nearby steam relief valve leak of auxiliary steam condensate (Figure 3). Samples were analyzed for ammonia, hydrazine, pH, and tritium. Tritium was detected at a concentration of 1,200,000 picocuries per liter (pCi/L) in catch basins CB 18 and CB 17. Plant-related gamma-emitting isotopes were not found in any of the samples. Based on concentrations of tritium detected in the catch basins, PSEG determined that the source of tritiated water was not from the auxiliary steam relief valve. PSEG personnel installed inflatable plugs to isolate catch basin CB 17, CB 18, and CB 19 from the stormwater outfall. Stormwater in the catch basins was collected and temporarily stored in tanks.
PSEG initiated an investigation to identify the source of the tritium. The investigation included evaluating nearby systems, structures, and components (SSCs) that contain tritium at concentrations greater than detected in the sample from the catch basin, groundwater investigation, and evaluation of storm drain sources.
To investigate groundwater, PSEG installed 15 temporary groundwater monitoring points using vacuum excavation techniques. Boreholes were advanced to approximately 10 feet below ground surface (bgs) and a perforated polyvinyl chloride (PVC) sleeve was installed into the borehole.
On April 23, 2010, based on the findings of the investigation, PSEG determined that the source of the tritium was a small leak (i.e., intermittent drip) from an expansion joint on the Salem Unit 2 plant vent. Condensate from the Salem Unit 2 plant vent leaked FINAL_1Q2014 RAPR_9.22.2014.doc 3
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey onto the Auxiliary Building roof and was transported to catch basin CB 17 via roof drain and stormwater collection system.
The Salem Unit 2 plant vent is a permitted gaseous effluent release point at the top of the Containment Building and is designed to direct condensation to the radioactive waste system from a low point drain that was found to be clogged. When the drain clogged, tritiated water leaked from an expansion joint in the Salem Unit 2 plant vent line. On May 13, 2010, PSEG cleared the blocked drain line and resolved the leak.
Subsequent to the detection of tritium in catch basins associated with the Unit 2 plant vent leak in April 2010, PSEG reevaluated programs, procedures, processes, and plant systems associated with the management of tritium across the Station. The self-assessment team identified that the Radiological Groundwater Protection Program (RGPP) well network, though inclusive of the entire Salem Unit 2 Station, could be further refined to identify leaks earlier by installing additional wells closer to potential sources. In November 2010, ten monitoring wells (wells DA, DB, DC, DD, DE, DF, DG, DH, DI, and DJ) were installed in the shallow, water-bearing unit within the limits of the cofferdam, to assist in identifying potential leaks from Salem Unit 2. Additional detail regarding the investigation of the Salem Unit 2 Plant Vent is provided in the Revised Salem Unit 2 Remedial Investigation Work Plan Addendum (ARCADIS 2013).
1.2 Groundwater Monitoring Program Objectives The objective of the quarterly groundwater monitoring program is to provide the best reasonable understanding of tritium in groundwater, including distribution, potential source(s), and containment.
PSEGs groundwater monitoring program combines a detailed knowledge and understanding of the following:
Site operations Conceptual site model Results of previous groundwater investigations and monitoring Historical concentration trends Performance of the GRS FINAL_1Q2014 RAPR_9.22.2014.doc 4
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Tritium concentrations detected in the seismic gaps (SGS Unit 1 and Unit 2)
Permitted gaseous and liquid effluent concentrations Meteorological data This information allows PSEG to identify potential sources of tritium detected in groundwater, which could be influenced by various factors including, but not limited to, meteorological events (e.g., precipitation and wind) and permitted gaseous effluents.
1.3 Recent Activities As described in the RAPR, Fourth Quarter 2013 (ARCADIS 2014a) and the Well AA-V Installation Report (ARCADIS 2014b), PSEG performed the following investigation activities following the detection of tritium in Vincentown formation well AA-V:
performed an extended purge on monitoring well AA-V, performed a mean hydraulic gradient study to evaluate the effects of tidal fluctuations on groundwater elevations and hydraulic gradient within the Vincentown Formation, and performed a comprehensive potable well search.
PSEG installed monitoring well AA-V to evaluate groundwater within the Vincentown Formation downgradient of the historical SFP release investigation area. The location was selected based on existing data indicating groundwater flow direction in the Vincentown Formation, its proximity to the baseline SPF plume and constraints associated with Station operations (i.e., surface and subsurface infrastructure). The well was installed at a location approximately 320 feet south of the SGS Unit 1 Reactor Building (Figure 2). Section 3.4.4 presents the results of samples collected from well AA-V during the current reporting period.
1.3.1 GRS Repair Activities During the reporting period, PSEG performed troubleshooting and equipment replacement activities to return auto pumping function to well AB. Specifically, activities included:
FINAL_1Q2014 RAPR_9.22.2014.doc 5
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey replacing the pump controller for well AB, and replacing the pump in well AB.
After completing the repair activities on February 20, 2014, all pumps operated in auto control (i.e., maintain constant water elevation).
1.4 Report Purpose and Organization This report summarizes groundwater remediation and monitoring activities conducted from January 1, 2014 through March 31, 2014 (reporting period). This report presents relevant background information, results and findings of groundwater monitoring activities conducted during the reporting period, and future actions for monitoring and remediating tritium in groundwater. This RAPR is organized as follows:
Section 2 - Data Evaluation. This section provides an overview of the data collected during the reporting period as part of the monitoring program.
Section 3 - Results. This section presents the results of groundwater monitoring activities performed during the reporting period. Groundwater analytical results are evaluated relative to regulatory criteria and previous monitoring results to identify changes in groundwater quality.
Section 4 - Groundwater Extraction. This section presents the operational status of the GRS during the reporting period.
Section 5 - Seismic Gap Drain Operation. This section presents the results of periodic tritium analysis of samples collected from the SGS Unit 1 and Unit 2 seismic gap drains, through the reporting period.
Section 6 - Summary. This section summarizes the results of meteorological, effluent and seismic gap data. In addition, a summary of groundwater monitoring results associated with the GRS operation activities is presented. This section also presents details regarding the reporting and schedule for future proposed activities.
Section 7 - References. This section lists the references cited in this RAPR.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 2. Data Evaluation Various data sets are evaluated during each reporting period to allow for a comprehensive understanding of Station conditions. The following sections describe the data collected during the reporting period, including meteorological measurements, effluent concentrations and groundwater monitoring activities.
2.1 Meteorological Data Local meteorological data are collected at the Station by an existing primary meteorological tower located in the southeastern portion of the property. The tower is a 300-foot structure, the base of which is located at 11.9 feet above mean sea level. The meteorological data reviewed as part of this RAPR includes wind speed, wind direction, and precipitation (humidity and solar radiation are also collected but not included in this analysis). Wind speed and direction are measured at the 33-, 150-, 197-, and 300-foot elevations at the primary tower. Precipitation data are collected via a rain gauge located at the ground level of the primary tower.
PSEG maintains a backup meteorological tower, consisting of a 33-foot utility pole, located 386 feet south of the primary tower. The primary tower serves as the main source of site meteorological data. The backup tower is used as a backup for periods of equipment unavailability on the primary tower. The backup tower is capable of providing measurements of temperature, wind speed, and wind direction at the 33-foot elevation.
Measurements are digitally collected every second. Meteorological data averages in the real time system are calculated and stored in separate 15-minute and hourly average files. Those values are running averages. The hourly data presented in Section 4.1 are the hourly running average files, sampled at the end of each hour.
2.2 Effluent Data Gaseous and liquid effluents are monitored in accordance with the SGS and HCGS Off-site Dose Calculation Manuals (ODCMs). The monitoring programs for both the SGS and HCGS are summarized below.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey 2.2.1 Salem Units 1 and 2 Gaseous Effluent The SGS has two generating units (Unit 1 and Unit 2) that are pressurized water reactors. Each unit has a plant vent located on the top of the Containment Building.
These vents are the final release points for permitted gaseous effluent releases (both continuous and batch releases) and are continuously monitored by installed radiation monitors. The plant vents are sampled weekly for tritium.
There are other, minor monitored releases from the Salem units such as the steam generator blowdown and auxiliary feedpump runs. The amount of radioactive material released through these pathways is documented in routine effluent release permits.
2.2.2 Hope Creek Gaseous Effluent The HCGS is a single-unit boiling water nuclear reactor that releases gaseous effluents from two plant vents located on the top of the Radwaste Building. These vents (the North Plant Vent and South Plant Vent) are the final release points for permitted gaseous effluent releases (both continuous and batch releases) and are continuously monitored by installed radiation monitors. The plant vents are sampled weekly for tritium.
A small quantity of gaseous effluent is released via the filtration, recirculation, and ventilation system (FRVS) vent located on the top of the containment building. Effluent is released from the FRVS during FRVS testing periods. During normal plant operations, the FRVS is maintained in a standby condition. The amount of radioactive material released through the FRVS is documented in routine effluent release permits.
2.2.3 Liquid Effluent Liquid effluent is subdivided into batch and continuous releases. A batch release is the discharge of liquid wastes of a discrete volume. Prior to sampling for analyses, each batch is isolated and then thoroughly mixed to assure representative sampling prior to permitted release to the Delaware River. A continuous release is the discharge of liquid wastes of a non-discrete volume (Salem ODCM, PSEG 2013a). Batch and continuous releases for the Station are collected from various sources as listed below.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Release Source/Pathway Location Type (Releases From)
GRS, service water drums (which are collected and disposed via the SGS Batch chemical waste basin) and the chemical volume control system monitor tanks Condensate release for blow-down of the steam generators and the SGS Continuous chemical waste basin Releases from the equipment sample tanks, floor drain sample tanks, HCGS Batch detergent drain tanks, and circulating water dewatering sump discharge HCGS Continuous Cooling Tower Blowdown Source: SGS and HCGS ODCM, PSEG 2013a and b 2.3 Water-Level Measurements On February 19, 2014, ARCADIS personnel collected depth-to-water (DTW) measurements from 68 monitoring wells across the Station using an interface probe.
The probe was introduced into each well and slowly lowered down the well column.
The DTW was recorded at the depth indicated by the pulsating tone of the probe. Prior to use in each well, the probe and probe tape were decontaminated using a Liquinox and tap water scrub followed by a distilled water rinse. Groundwater elevations were calculated using the DTW measurements and the reference point elevation for each monitoring well. Monitoring well construction details and reference point elevations are presented in Table 1. As described in Section 3.3, groundwater level measurements were used to produce a groundwater elevation contour map within the more permeable shallow, water-bearing unit beneath the Station (Figure 4). Additionally, cross-sections depicting groundwater level measurements are shown on Figures 5 through 9.
2.4 Groundwater Sample Collection Monitoring wells included in the remedial activities at the SGS are grouped into four categories based on location and groundwater monitoring zone as follows:
Salem Unit 1 - Shallow Wells Installed Within the Cofferdam Salem Unit 2 - Shallow Wells Installed Within the Cofferdam Shallow Wells Installed Outside the Limits of the Cofferdam FINAL_1Q2014 RAPR_9.22.2014.doc 9
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Vincentown Formation Wells Two water-bearing zones present beneath the Station are part of the groundwater investigation: the shallow, water-bearing unit and the deeper confined groundwater of the basal sand unit and Vincentown Formation. The shallow, water-bearing unit consists of dredge spoils, engineered fill, tidal marsh deposits, and discontinuous Quaternary riverbed deposits, and is present between approximately 10 to 40 feet bgs.
In general, the dredge spoils, engineered fill, and tidal marsh deposits are characterized by relatively high porosity and low permeability. Occasional lenses of sand within the dredge spoils may contain perched water within a few feet of the ground surface.
Groundwater elevations are influenced by surface and subsurface features of the SGS.
As an example, this influence is observed when comparing groundwater elevations inside and outside the cofferdam structure at the SGS. The cofferdam was installed during the construction of the SGS and is made of concrete and steel. The cofferdam affects the horizontal flow of groundwater within and around it. When groundwater levels are elevated, groundwater generally flows radially over the top of the structure; when water levels are lower, the flow directions may be more limited as a result of the subsurface structures. In general, the subsurface structures (concrete and steel) result in higher groundwater elevations within the cofferdam than those observed outside the feature.
Groundwater sample collection is conducted in accordance with the schedule presented in Table 2 although the schedule is adaptively managed to ensure that representative data are collected to provide the information necessary to evaluate groundwater quality conditions. Two pumping wells were not sampled during the reporting period. Well AB was not sampled in January and February 2014 because the dedicated pump located in the well was not operating. Well AN was not sampled in March 2014 because the pump located in the well was not operating.
In addition to the low-flow techniques described below, groundwater samples were collected from six GRS pumping wells (wells S, AB, AD, AJ, AN, and AT) via the effluent discharge ports (with the exceptions listed above).
2.4.1 Low-Flow Sampling Monitoring wells were sampled following the low-flow purging and sampling techniques in accordance with the Field Sampling Procedures Manual (NJDEP 2005). In addition, FINAL_1Q2014 RAPR_9.22.2014.doc 10
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey former GRS pumping well AS was sampled using low-flow purging techniques. The wells were purged and sampled using a dedicated bladder pump equipped with a Teflon bladder and dedicated polyethylene tubing. The purge rate was adjusted between 100 milliliters per minute (mL/min) and 500 mL/min so the water level within a well was not lowered by more than 0.3 foot. The water level within the well was monitored throughout the purge. Additionally, field parameters (pH, temperature, conductivity, dissolved oxygen [DO], oxidation-reduction potential [ORP], and turbidity) were monitored continuously using a flow-through assembly. Other observations, such as color and odor of purge water, were recorded throughout the purge. Each monitoring well was purged until three consecutive measurements (taken at 5-minute intervals) of pH, conductivity, DO, ORP, and turbidity stabilized to within one standard unit, 3%, 10%, 10 millivolts, and 10%, respectively.
Once field parameter measurements stabilized, groundwater samples were collected into dedicated sample containers directly from the discharge tubing. The samples are maintained under chain of custody procedures throughout sample handling, screening, shipping and laboratory analysis process. Samples are submitted to Station Chemistry for radiological analysis screening prior to shipment to Teledyne Brown Engineering (Teledyne) located in Knoxville, Tennessee, for radiological analysis. Additionally in accordance with NJDEP request, split samples are submitted to GEL Laboratories located in Charleston, South Carolina.
2.5 Mass Flux Estimation of Tritium to the Delaware River To calculate the mass flux to the Delaware River, the tritium concentration was estimated using the average tritium concentration detected in groundwater samples collected from monitoring wells located nearest to the Delaware River during the reporting period. To estimate the tritium concentration between monitoring wells with detectable tritium concentrations, the mean of the two concentrations was used. This value was assumed to be consistent along the distance between the wells. To estimate the concentration between one monitoring well with detectable tritium concentrations and one monitoring well without detectable concentrations, a concentration equal to that from the monitoring well with detectable tritium is assumed to be consistent along the distance between the wells. To estimate the tritium concentration between two monitoring wells without detectable tritium concentrations, it was assumed that no tritium mass was between the wells. If data was not available for a particular month, the most recent result was used for the calculation. This analysis was performed separately for the shallow, water-bearing unit and the relatively deeper groundwater in the basal sand and Vincentown Formation. The distance between the well pairs was FINAL_1Q2014 RAPR_9.22.2014.doc 11
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey measured as the straight-line distance between the two wells using their geographical surveyed northing and easting values.
The mass flux was calculated using the following equation:
Mass Flux (M) = Volumetric Flux (Q) x Concentration (C)
The volumetric flux was estimated as:
Q=Kxixbxw
- Where, K = Average Hydraulic Conductivity i = Average Hydraulic Gradient b = Average Saturated Thickness w = Plume Width For the shallow, water bearing unit, the following values were assumed for the calculation:
K= 6.5 feet/day (ARCADIS 2004a) i = 0.004 feet/feet (ARCADIS 2004a) b = 27 feet (22 feet Hydraulic & Structural Fill + 5 feet River Deposits)
The plume width (w) and concentration (C) were calculated as described above.
Within the shallow, water bearing unit, wells BB and BP were selected as the terminal lateral points. Tritium was not detected in groundwater samples collected from monitoring wells including and beyond these points. Between these two points, wells located nearest to the Delaware River are: wells AH-D, AG-D, Z, Y, BC, BE, BG, BH, BK, BL and BO.
For the deeper groundwater, the following values were assumed for the calculation:
Kbasal sand = 5 feet/day (Dames & Moore 1974)
KVincentown Formation = 11.34 feet/day (Calculated using results of a specific capacity test performed on Well AA-V in August 2013) i = 0.0051 feet/feet (ARCADIS 2014b) b = 38 feet (18 feet of basal sand + 20 feet of Vincentown formation [assumed top 20 feet])
The plume width (w) and concentration (C) were calculated as described above.
For the deeper groundwater, wells P and L were selected as the terminal lateral points.
Between these two points, well AA-V is located nearest to the Delaware River.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 3. Results This section presents details regarding the various data evaluated and results of groundwater monitoring activities completed during the reporting period.
3.1 Meteorological Data As described in Section 2.1, PSEG maintains primary and backup meteorological (MET) towers at the Station to collect local meteorological data including wind speed, wind direction, humidity, solar radiation and precipitation.
3.1.1 Precipitation Hourly precipitation measurements from January 1, 2013 through March 31, 2014 were used to calculate the monthly cumulative precipitation amounts. Measurements are shown in inches of liquid. Frozen precipitation is melted and the equivalent liquid volume is measured. Both the hourly data and monthly volumes for 2013 and 2014 (through March 31, 2014) are shown on Figure 10.
The recorded precipitation data for the Station were compared with average monthly totals (regional average) and historical monthly totals (historical regional mean) for the region (southern New Jersey) in January, February, and March 2014.
2014 Station Regional Average1 Historical Regional Mean2 January 2.31 3.17 3.47 February 5.12 5.35 3.13 March 3.36 4.76 4.04 Notes:
Precipitation measurement provided in inches.
1 Regional average values are calculated from an average of monthly precipitation totals recorded at approximately ten stations throughout southern New Jersey.
2 Historical regional mean precipitation values are calculated from the mean monthly precipitation totals from 1895-2013.
Source: http://climate.rutgers.edu/stateclim_v1/data/south_njhistprecip.html The above table indicates that compared to the regional average, the Station experienced below average precipitation in January, February, and March 2014.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey When compared to the historical regional mean, the Station experienced below average precipitation for the months of January and March 2014, and above average precipitation in February 2014.
3.1.2 Wind As described in the Early Site Permit Application, Site Safety Analysis Report (PSEG 2014) wind direction in the area of the Station is seasonally dependent. In general, the typical wind direction at the Station is from the northwest during the autumn, winter, and spring months, and from the south/southwest during the summer months.
Wind data are collected at the 33-foot level of the primary MET tower and are used to generate wind rose diagrams, which are shown on Figure 11. The wind data for each month in the reporting period (January 2014, February 2014, and March 2014) and for the reporting period in its entirety are shown on Figure 11 and discussed below.
The January 2014 wind rose displays dominant wind directions from the west/northwest (13.71 percent of the time), the northwest (12.23 percent of the time, and to a lesser extent from the southeast (9.54 percent of the time) and from the north/northwest (9.01 percent of the time).
The February 2014 wind rose displays dominant wind directions from the northwest (14.73 percent of the time), the north/northwest (14.58 percent of the time), and to a lesser extent from the north/northeast (9.23 percent of the time) and from the north (8.93 percent of the time).
The March 2014 wind rose displays dominant wind directions from the north (13.84 percent of the time), the northwest (12.10 percent of the time) and from the north/northwest (10.62 percent of the time).
The first quarter 2014 wind rose shows dominant frequencies from the northwest (12.96 percent of the time) and from the north/northwest (11.30 percent of the time). The remaining directions include a group (northeast, west, southeast, north/northeast, north, and west/northwest) with frequencies of occurrence that range from 5.83 to 8.70 percent of the time, and a group (east, east/southeast, east/northeast, southwest, south, west/southwest, south/southeast, and south/southwest) with frequencies of occurrence that range from 1.76 to 4.72 percent of the time.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey The first quarter 2014 observed wind direction is consistent with expected dominant wind direction trends during the winter months. Additionally, during precipitation events the dominant wind direction was observed coming from the north/northeast, northeast, and east/northeast during the reporting period.
3.2 Effluent Data PSEG provided ARCADIS with the effluent data presented below. As previously described, the data provided includes batch and continuous releases for both liquid effluent and gaseous effluent. This information, presented in Table 3, is shown as total tritium activity in curies (Ci).
3.2.1 Gaseous Effluent During the reporting period, the Station released a total of 64.83 Ci of tritium to the atmosphere via permitted gaseous effluent releases.
2014 SGS Unit 1 SGS Unit 2 HCGS January 0.040 1.101 14.650 February 3.912 0.047 15.500 March 1.982 1.972 25.630 Notes:
Gaseous effluent tritium activity is presented in Ci.
Source: PSEG Year-to-date through the end of the first quarter 2014, a combined total of 64.834 Ci of tritium has been released to the atmosphere at the Station; the majority of which was released during March 2014 (29.584 Ci), when compared to January 2014 (15.791 Ci) and February 2014 (19.459 Ci).
3.2.2 Liquid Effluent During the reporting period, the Station released a total of 318.555 Ci of tritium to the Delaware River via permitted liquid effluent releases. As shown below, the majority of the liquid effluent released from the Station during the reporting period occurred in March 2014 (299.223 Ci) when compared to January 2014 (17.988 Ci) and February 2014 (1.344 Ci).
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey 2014 SGS Unit 1 SGS Unit 2 HCGS January 4.555 9.261 4.172 February 0.169 0.249 0.926 March 199.100 97.420 2.703 Notes:
Liquid effluent tritium activity is presented in Ci.
Source: PSEG 3.3 Groundwater Elevation Two water-bearing zones present beneath the Station are part of the groundwater investigation: the shallow, water-bearing unit and the deeper confined groundwater of the basal sand unit and Vincentown Formation. Generally, groundwater in both of these zones flows toward the Delaware River. Shallow groundwater is locally affected by numerous subsurface structures including the cofferdam surrounding the SGS.
Groundwater elevation data collected quarterly through the reporting period are presented in Table 4. Groundwater level measurements were used to produce a groundwater elevation contour map within the shallow, water-bearing unit beneath the Station (typically the riverbed deposits and engineered fill). The current well network is sufficient to characterize overall groundwater gradients in this unit at the Station. A groundwater elevation contour map is shown on Figure 4. General characteristics of groundwater flow are discussed below.
As shown on Figure 4, shallow groundwater beneath the Station flows in a generally radial pattern away from the two power blocks. Groundwater eventually flows to the perimeter of the island toward the Delaware River Estuary. The gradient is generally to the southwest and toward the shoreline. Groundwater elevations and interpreted contours are consistent with historical groundwater flow observations.
In December 2006, PSEG installed wells BW and BX at the SGS. The wells were installed adjacent to the auxiliary boiler building and completed to a depth of 10 feet bgs. Storm water runoff from the surrounding vicinity has been observed puddling near the auxiliary boiler following storm events. This puddling effect is believed to be caused by the drainage of the compacted structural fill in this area. The poor drainage and low hydraulic conductivity of the soils causes a mounding of groundwater as evident in the groundwater contour figures.
In December 2010, PSEG installed well BZ at the HCGS adjacent to the condensate storage tank (CST). During installation activities, a buried concrete pad was FINAL_1Q2014 RAPR_9.22.2014.doc 16
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey encountered at approximately 39-feet bgs and the well was constructed above the pad.
The close proximity of well BZ to the Hope Creek Reactor Building, coupled with the concrete pad under the well and the proximity to the CST pad likely affects groundwater flow in the immediate vicinity of well BZ causing a slight groundwater mounding effect as evident in the groundwater contours shown on Figure 4.
As described in the Well AA-V Installation Report (ARCADIS 2014b) a mean hydraulic gradient study was performed as part of the investigation into groundwater quality in the Vincentown Formation. The study confirmed the fluctuations observed in the Delaware River are in sync with the hydrostatic pressure response observed in the Vincentown Formation wells, and there is little time delay between tidal fluctuations in the Delaware River and monitoring wells. Wells AA-V, P, and L showed the greatest fluctuation in groundwater (approximately 3 feet) which is expected since wells AA-V, P, and L are located closer to the Delaware River compared to wells K, Q, and V. Wells K and V are located farthest from the Delaware River and had moderate fluctuations of approximately 1 foot. Well Q showed virtually no influence from tidal fluctuation.
Results of the mean hydraulic calculations and spatial interpretation confirm groundwater in the Vincentown Formation flows toward the Delaware River.
3.4 Groundwater Sampling This section provides the results of groundwater sampling activities relative to depth (shallow, water bearing unit or Vincentown Formation), proximity to the cofferdam (i.e.,
within or outside the cofferdam), reactor unit, and historical results. Analytical results since monitoring commenced are presented in Table 5. Recent analytical tritium results for shallow groundwater samples collected from the Station monitoring wells are shown on Figures 12 and 13. Figure 12 shows tritium concentrations across the SGS. Figure 13 shows the horizontal extent of tritium in groundwater at the following times:
At the completion of the remedial investigation (March 2004; Baseline Tritium Isoconcentration; Panel 1)
One year prior to the reporting period (March 2013; Panel 2)
During the March 2014 sampling event (Panel 3)
Additionally, cross-sections depicting tritium concentrations are shown on Figures 5 through 9.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey 3.4.1 Salem Unit 1 - Shallow Wells Installed Within the Limits of the Cofferdam Chart 3-1 presents the previous one year of analytical results for groundwater samples collected from shallow monitoring wells installed within the limits of the cofferdam, adjacent to the SGS Unit 1 fuel handling and containment buildings. The concentrations shown on Chart 3-1 for well AC represent samples collected via low-flow techniques. Wells within the cofferdam adjacent to the SGS Unit 1 monitor the interval from 10 to 20 feet bgs. Analytical results from monthly groundwater samples collected during this reporting period are summarized below.
Monitored Water-Bearing Unit Monitoring Well Shallow wells installed within the Wells M, N, O, R, AC, AE, AI, AM, AN, cofferdam - Unit 1 and AO1 Notes:
1 Data obtained from sampling well AO did not provide additional information pertaining to the extent of the tritium plume and therefore, PSEG discontinued sampling well AO after the March 2013 event.
Table 6 presents a summary of the most recent analytical results from well AC. The samples collected from well AC during the reporting period were collected via low-flow sampling techniques as described in Section 2.4. Previously, as presented in Table 6A, samples were collected using grab, low-flow, volume-averaged and extended purge sampling techniques. In addition to the monthly tritium sample collected during the January groundwater sampling event, PSEG also collected samples for hard-to-detect, transuranic, and gamma radiological isotopes, the results of which are presented in Table 6B.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Chart 3-1: Tritium Concentrations Detected in Salem Unit 1 Shallow Wells Installed Within the Cofferdam Notes:
1 Tritium concentrations are shown on a logarithmic scale to facilitate presentation of tritium analytical results.
2 Well AN was not sampled in March 2014 because the dedicated pump was not operating.
3 Data obtained from sampling well AO did not provide additional information pertaining to the extent of the tritium plume and therefore, PSEG discontinued sampling well AO after the March 2013 event.
Analytical results for groundwater samples collected during this reporting period are summarized below.
During the reporting period, tritium was detected in samples collected from four monitoring wells (wells O, AC, AE, and AM) within the SGS Unit 1 cofferdam at concentrations greater than the NJDEP Class II-A Groundwater Quality Standard (GWQS) for tritium of 20,000 pCi/L.
During the reporting period, tritium concentrations in the SGS Unit 1 cofferdam wells ranged from 1,900 pCi/L (March 2014) in well AI to 349,000 pCi/L (March 2014) in well AC. Historically, the highest concentrations at the Station have been observed in well AC.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey A comparison between samples collected via volume-averaged purge techniques and the sample collected following the extended purge demonstrates reduced tritium concentrations after purging 1,000 gallons of groundwater from well AC.
The reduced concentration detected in the sample following the extended purge indicates hydraulic heterogeneities exist within the engineered fill. That is, tritium in the immobile pore fraction (zones with relatively lower permeability and higher tritium concentration) is likely being released into mobile pore fraction (zones with relatively higher permeability and lower tritium concentration). As water was drained from the mobile pore fraction during the extended purge, groundwater from the surrounding area with lower concentrations was able to travel to the well, thus showing the screened interval of the well is made up of zones with higher and lower concentrations of tritium. This also supports the hypothesis that the conditions detected in well AC are localized.
Hard-to-detect, transuranic, and gamma radiological isotopes were not detected, with the exception of potassium 40, in samples collected from well AC during the January 2014. Potassium 40 is a naturally occurring isotope and not believed to be associated with Station operations. The analytical results from groundwater samples collected from well AC do not indicate the presence of a continued release to the environment.
From approximately January 2011 through September 2012, tritium concentrations detected in well N showed an increasing trend. This increase is coincident with decreased performance and reliability of the GRS. Pumping wells AJ and S are closest to well N and function to hydraulically control the plume. From September 2012 through May 2013, tritium concentrations detected in well N showed a decreasing concentration. This decrease is coincident with a return to groundwater recovery operation in nearby GRS wells AJ and S. From May 2013 through August 2013, tritium was detected in well N at increasing concentrations. During this timeframe, well S was out of service due to controller malfunction. From August 2013 through the end of the reporting period, tritium concentrations generally decreased in well N. During this period, PSEG addressed the reliability of pumping wells AJ and S through replacement of pump controllers and level transmitters.
PSEG expects the tritium detected in well N to stabilize or further decrease as the pumps continue to reduce the area of groundwater containing tritium.
Since July 2011, tritium concentrations within the Salem Unit 1 cofferdam appear stable with some moderate fluctuation over time, with the exception of the recent detections in well AC that appear to be an artifact of sampling technique.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Historically, the tritium concentrations detected in well AC have decreased by approximately 97 percent since installation.
3.4.2 Salem Unit 2 - Shallow Wells Installed Within the Limits of the Cofferdam Chart 3-2 presents the previous year of analytical results for groundwater samples collected from shallow monitoring wells installed within the limits of the cofferdam, adjacent to the SGS Unit 2 fuel handling and containment buildings. Wells within the cofferdam adjacent to the SGS Unit 2 monitor the interval from 6 to 22 feet bgs.
Analytical results from monthly groundwater samples collected during this reporting period are summarized below.
Monitored Water-Bearing Unit Monitoring Well Shallow wells installed within the Wells DA, DB, DC, DD, DE, DF, DG, DH, cofferdam - Unit 2 DI, and DJ FINAL_1Q2014 RAPR_9.22.2014.doc 21
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Chart 3-2: Tritium Concentrations Detected in Salem Unit 2 Shallow Wells Installed Within the Cofferdam Analytical results for groundwater samples collected during this reporting period are summarized below.
During the reporting period, tritium was not detected in samples collected from monitoring wells installed within the SGS Unit 2 cofferdam at concentrations greater than the NJDEP Class II-A GWQS of 20,000 pCi/L.
Tritium concentrations ranged in the SGS Unit 2 cofferdam wells from 827 pCi/L (January 2014) in well DJ to 15,600 pCi/L (February 2014) in well DB.
Since January 2013, tritium concentrations detected in wells DA, DC, DE, DF, DH, DI, and DJ appear stable with some expected moderate fluctuation over time.
Tritium concentrations detected in wells DD and DG have demonstrated a decrease over the last year, returning to historical concentration ranges observed for these wells. Tritium concentrations detected in well DB increased during the reporting period.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey 3.4.3 Shallow Wells Installed Outside the Limits of the Cofferdam Chart 3-3 presents the previous year of analytical results for groundwater samples collected from shallow monitoring wells installed outside the limits of the cofferdam.
Shallow wells outside the cofferdam are generally screened either in the riverbed deposits located 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 during the supplemental investigation completed in August 2003. Five wells (wells S, AB, AD, AJ, and AT) installed outside the limits of cofferdam are used as extraction points for the GRS.
Monitored Water-Bearing Monitoring Well Unit Wells S1, T, U, W, Y, Z, AA, AB1,2, AD1, AF, AG-D, Shallow wells installed outside AG-S, AH-D, AH-S, AJ1, AL, AP, AR, AS3, AT1, and the limits of the cofferdam CA Notes:
1 Pumping wells S, AB, AD, AJ, and AT were sampled during the reporting period via effluent discharge ports and are included in Chart 3-3.
2 Well AB was not sampled in January and February 2014 because the dedicated pump was not operating.
3 Well AS is a former GRS pumping well and was sampled during the reporting period using low-flow groundwater sampling techniques.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Chart 3-3: Tritium Concentrations Detected in Shallow Wells Installed Outside the Limits of the Cofferdam Notes:
1 Unfilled markers signify sample results with tritium concentrations less than the laboratory lower limit of detection (LLD). The symbols for well T and for well Y are shown as unfilled because all of the sample results shown on Chart 3-3 yielded tritium concentrations less than the LLD.
2 Samples were not collected from well AB in January and February 2014 because the dedicated pump was not operating.
Analytical results for groundwater samples collected during this reporting period are summarized below.
During the reporting period, tritium was detected in samples collected from two wells (GRS pumping wells S and AD) outside the limits of the SGS cofferdam at concentrations greater than the NJDEP Class II-A GWQS of 20,000 pCi/L.
Tritium was detected in shallow monitoring wells, excluding GRS pumping wells, installed outside the cofferdam at concentrations ranging from 227 pCi/L (February 2014) in well U to 16,200 pCi/L (January 2014) in well AS.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey During the reporting period, groundwater samples were collected monthly from GRS wells AB, AD, AJ, AT, and S, with the exception of well AB which was not sampled in January and February 2014 because the dedicated pump was not operating.
Tritium concentrations detected in monitoring wells installed outside the limits of the cofferdam, with the exception of GRS pumping wells, appear stable with some expected moderate fluctuation over time compared to the previous year.
3.4.4 Vincentown Formation Wells Chart 3-4 presents the previous one year of analytical results for groundwater samples collected from the deeper monitoring wells installed in the Vincentown Formation.
Vincentown Formation monitoring wells are screened below the clay confining unit that separates the shallow, water-bearing unit from the Vincentown Formation.
Monitored Water-Bearing Unit Monitoring Well Vincentown Formation Wells K, L, P, Q, V, CB1 , and AA-V2 Notes:
1 Well CB was abandoned in May 2013.
2 Well AA-V was installed in June 2013.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey Chart 3-4: Tritium Concentrations Detected in Wells Installed Within the Vincentown Formation Notes:
1 Unfilled markers signify sample results with tritium concentrations less than the laboratory LLD.
2 Well CB was abandoned in May 2013 and therefore removed from the sampling program beginning in June 2013.
3 Well AA-V was installed in June 2013.
Analytical results for groundwater samples collected during this reporting period are summarized below.
Tritium was not detected in samples collected from monitoring wells installed in the Vincentown Formation at concentrations greater than the NJDEP Class II-A GWQS of 20,000 pCi/L.
During this reporting period, tritium was not detected in groundwater samples collected from Vincentown Formation monitoring wells, with the exception of well AA-V, at concentrations greater than the laboratory LLD. Tritium was detected in FINAL_1Q2014 RAPR_9.22.2014.doc 26
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey well AA-V at a peak concentration of 8,130 pCi/L (March 2014) during the reporting period.
Tritium concentrations detected in well AA-V range from 6,930 pCi/L (January 2014) to 8,130 pCi/L (March 2014) during the reporting period.
Since 2012, tritium has not been detected in four of seven wells (wells K, L, P, and Q) installed within the Vincentown Formation.
3.5 Mass Flux Estimation of Tritium Reaching the Delaware River The estimated flux of tritium in groundwater being transported to the Delaware River was calculated, as presented in Section 2.5, using the results of samples collected from monitoring wells closest to the river. The individual details of each calculation are provided in Appendix A.
During the reporting period, the mass flux within the shallow, water bearing unit was calculated to be 0.0111 Ci; and within the deeper groundwater to be 0.1168 Ci. Based on the assumptions and calculations presented, the estimated total mass flux of tritium in groundwater reaching the Delaware River for the reporting period is 0.128 Ci.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 4. Groundwater Extraction Groundwater extraction was selected as the remedial strategy for tritium in groundwater and operation of the full-scale system was initiated on February 16, 2005.
The objectives of the full-scale GRS consist of maintaining hydraulic containment and reducing tritium concentrations in the shallow, water-bearing unit. When fully operational, the GRS has the capacity to pump from six wells (wells S, AB, AD, AJ, AN, and AT). Two wells (wells AS and AO) are permanently offline. The GRS discharges in accordance with the Stations United States Nuclear Regulatory Commission (USNRC) license.
In November 2013, PSEG installed new pressure transducers in all six GRS pumping wells, replaced the pump in wells AB and AD, and replaced the pump controllers for wells AJ and S. These activities returned all six GRS wells to auto pumping function. In December 2013, the field team identified well AB was not pumping.
4.1 Reporting Period Status In January and February 2014, the GRS operated utilizing wells AT, AN, AD, AJ, and S in auto control. Well AB was offline in January and a portion of February while troubleshooting activities took place. Pumping was restored to well AB in February when troubleshooting resolved electrical challenges. In March 2014, field team members identified well AN was out of service. Based on available information, the pump appears to be fouled with precipitated minerals. Maintenance on the pump is scheduled to occur in June. In total, the GRS pumped approximately 249,000 gallons during the reporting period.
Figure 14 shows the effectiveness of groundwater remediation activities conducted using the GRS, including both the pilot study and the full-scale system. The efficiency of the GRS is emphasized by the decrease and stabilization of system effluent concentrations since the activation of the full scale system in February 2005. As the overall mass remaining in the plume decreases, so will the rate of tritium recovery by the GRS based on the concentrations recovered.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 5. Seismic Gap Drain Operation PSEG operates drains in the styrofoam-filled seismic gaps located between the SGS Unit 1 FHB and Unit 2 FHB and the adjacent auxiliary building. Each seismic gap is approximately six-inches wide and extends vertically from grade (100 feet Plant Datum
[PD]) to the top of the concrete foundation of the fuel handling building (approximately 63 feet PD). Beneath the seismic gap is 33 feet of lean concrete foundation.
The seismic gap drains were installed at the 78 foot PD elevation (negative 12 feet msl) and since 2007 have been continuously left open to drain accumulated water creating an in-gradient toward the seismic gap. The water that accumulates in the seismic gap drains into the Auxiliary Building and is handled in accordance with Station procedures and permits. The drain also provides control for residual contamination within the Unit 1 seismic gap resulting from the accumulation of SFP water by permitting controlled draining of the residual contamination.
5.1 Salem Unit 1 Table 7 and Figure 15 summarize the results of periodic tritium analysis from the Unit 1 seismic gap. A comparison of Figure 13 (Tritium Isoconcentration Map - March 2014) and Figure15 (Unit 1 - Tritium Concentrations in Water Recovered Through Seismic Gap Drain Operation) indicates that concentrations of tritium in water recovered from the Unit 1 seismic gap have been consistently greater than those detected in groundwater samples collected from wells AC and AM, which are located southeast and southwest of the seismic gap, respectively. Continuous operation of the Unit 1 seismic gap drain is effectively removing SFP water in the seismic gap. Tritium concentrations in the water being removed from the gap (ranging from 84.3 million pCi/L to 125 million pCi/L during the reporting period) indicate that the draining appears to be establishing a preferential flow path toward the seismic gap drain as concentrations in the wells closest to the gap are three to four orders of magnitude less than the concentrations detected in the seismic gap drain. Draining of the seismic gap promotes a localized hydraulic head less than that present in the geologic materials present outside the seismic gap. Therefore, the gap drain acts as an engineering control that creates an inward gradient for groundwater flow into the seismic gap thus limiting the potential for a discharge to the environment from the gap.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey 5.2 Salem Unit 2 Monitoring of water drained from the Unit 2 seismic gap acts as a mechanism of early detection for a potential release from the Unit 2 SFP. Samples of recovered water collected from the Unit 2 seismic gap drain typically contain tritium levels (ranging from 43,400 pCi/L to 163,000 pCi/L during this reporting period) that are several orders of magnitude less than those observed in the Unit 1 seismic gap. In addition, gamma emitting isotopes and boron, found in primary water, are not typically detected in the samples collected from the Unit 2 seismic gap drain. As such, the limited presence of these constituents supports PSEGs hypothesis that the constituents detected in the Unit 2 seismic gap are associated with the Unit 1 spent fuel pool leak and the constituents have migrated along the seismic gap to the Unit 2 seismic gap drain.
Table 8 and Figure 16 summarize the results of periodic tritium analysis from the Unit 2 seismic gap.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey
- 6. Summary This section presents a summary of historical trends, current results, and future actions.
6.1 Historical Trends and Current Results In summary:
Compared to the monthly regional average, the Station experienced below average precipitation in January, February, and March 2014. When compared to the historical regional mean monthly totals, the Station experienced below average precipitation for the months of January and March 2014, and above average precipitation in February 2014.
The dominant wind direction for the reporting period was observed to be from the northwest, which is consistent with expected wind direction typically observed during the fall and winter months.
During the reporting period, the Station reportedly released a total of 64.834 Ci of tritium to the atmosphere via permitted gaseous effluent releases; the majority of which was released during March 2014 (29.584 Ci), when compared to January 2014 (15.791 Ci) and February 2014 (19.459 Ci).
During the reporting period, the Station reportedly released a total of 318.555 Ci of tritium to the environment via permitted liquid effluent releases; the majority of which was released in March 2014 (299.223 Ci).
Since 2010, the greatest tritium concentrations detected in groundwater have been observed in well AC. This shallow well is screened within the area affected by the SFP release and is located near the SGS Unit 1 plant vent.
During this reporting period, tritium was detected in six monitoring wells (wells AC, AD, AE, AM, O, and S) at concentrations greater than the NJDEP Class II-A GWQS of 20,000 pCi/L. Wells AC, AD, AM, O, and S were historically within the baseline plume. Tritium detected in groundwater samples from well AC indicates a localized area with higher concentrations remains in groundwater. This area of increased concentration is probably associated with the immobile pore fraction and is being addressed by operation of the GRS.
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey During the reporting period, groundwater within the general area of the baseline tritium plume was hydraulically controlled by the active pumping from wells S, AB, AD, AJ, AN, and AT. Concentrations detected in the GRS pumping wells is consistent with previous years, showing that as the overall mass remaining in groundwater decreases, so will the rate of tritium recovery by the GRS based on the concentrations recovered.
Continuous operation of the Unit 1 seismic gap drain is effectively removing SFP water from the seismic gap and has established a preferential flow path between the seismic gap drain and water in the gap. The limited detection of gamma emitting isotopes and boron supports PSEGs hypothesis that the constituents detected in the Unit 2 seismic gap are associated with the Unit 1 spent fuel pool leak and the constituents have migrated along the seismic gap to the Unit 2 seismic gap drain. Given the behavior of tritium and its abundant presence within the cofferdam, tritium alone cannot be solely used as an indication of the source of the water collected in the Unit 2 seismic gap. At this time, there is not conclusive evidence of a similar SFP leak or an un-permitted release from the SGS Unit 2 operations.
The current well network continues to adequately characterize the vertical and horizontal extent of tritium concentrations in shallow groundwater at the Station.
As shown on Figures 5 through 9 (vertical extent) and Figure 13 (horizontal extent) the extent of tritium concentrations within the shallow, water bearing unit is delineated.
During the reporting period, tritium was not detected at a concentration greater than the laboratory LLD in monitoring wells in the Vincentown Formation, with the exception of well AA-V. Tritium concentrations detected in groundwater samples collected from well AA-V range from 6,930 pCi/L (January 2014) to 8,130 pCi/L (March 2014).
During the reporting period, the mass flux within the shallow, water bearing unit was calculated to be 0.0111 Ci; and within the deeper groundwater to be 0.1168 Ci. Based on the assumptions and calculations presented, the total estimated mass flux of tritium in groundwater reaching the Delaware River is 0.128 Ci.
6.2 Future Actions Future actions planned for the monitoring program include:
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Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey In the second quarter 2014, PSEG will continue groundwater monitoring (sampling and elevation measurements) at the frequency presented in Table 2. PSEG will track effluent (liquid and gaseous) discharges and meteorological data as part of the operating permit, and tritium concentrations in groundwater as part of the RGPP.
PSEG will continue operating the GRS. Preventative maintenance activities are scheduled to be performed in June.
On September 16, 2013, PSEG received an approval letter from the NJDEP accepting the modifications PSEG proposed for the Revised Salem Unit 2 RIWP Addendum. On October 11, 2013, PSEG submitted three copies of the Revised Salem Unit 2 RIWP Addendum to NJDEP. PSEG anticipates implementing the activities in the work plan in 2014.
In April 2013, PSEG implemented a tritium recapture study to document tritium concentrations in rain water, storm water and HVAC condensate and evaluate the potential effect on groundwater quality. The study was originally intended to be performed over a 12-month period; however, the study has been extend to collect additional data. Following completion of the study, PSEG will discuss the findings with NJDEP.
As described in the revised April 2014 Remedial Action Work Plan Addendum, PSEG is planning to install a new deep monitoring well near existing well S as part of overall plan to investigate tritium in groundwater beneath the confining unit to further refine the conceptual site model. In addition, PSEG will temporarily recover water from well AC to reduce the overall mass of tritium remaining in the plume and monitor the effect on downgradient wells.
- 7. References ARCADIS. 2003. Remedial Investigation Work Plan, Salem Unit 1. PSEG Nuclear, LLC. June.
ARCADIS G&M, Inc. (ARCADIS). 2004a. Remedial Investigation Report, Salem Unit 1.
ARCADIS G&M, Inc. (ARCADIS). 2004b. Remedial Action Work Plan, Salem Unit 1.
FINAL_1Q2014 RAPR_9.22.2014.doc 33
Remedial Action Progress Report First Quarter 2014 Salem Generating Station Hancocks Bridge, New Jersey ARCADIS U.S., Inc. (ARCADIS). 2011. PSEG Nuclear Generation Facilities, Addendum to the 2006 Site Investigation Reports.
ARCADIS. 2013. Revised Salem Unit 2 Remedial Investigation Work Plan Addendum.
ARCADIS. 2014a. Remedial Action Progress Report, Fourth Quarter 2013. PSEG Nuclear, LLC. March.
ARCADIS. 2014b. Well AA-V Installation Report. PSEG Nuclear, LLC. March.
Dames and Moore. 1974. Report-Foundation Studies, Proposed Hope Creek Generating Station. PSEG Nuclear, LLC. May.
New Jersey Department of Environmental Protection. 2005. Field Sampling Procedures Manual.
PSEG. 2011. 2010 Annual Radioactive Effluent Release Report, May 2011.
PSEG. 2013a. Salem Units 1 and 2 Offsite Dose Calculation Manual, Revision 27, December 2013.
PSEG. 2013b. Hope Creek Offsite Dose Calculation Manual, Revision 27, December 2013.
PSEG. 2014. Early Site Permit Application, Site Safety Analysis Report, Revision 3, March 2014.
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