ML042510589

Yankee Nuclear Plant Site, Historical Site Assessment, Yankee Atomic Electric Company, Volume I

ML042510589
Person / Time
Site:	Yankee Rowe
Issue date:	01/21/2004
From:	Yankee Atomic Electric Co
To:	NRC/FSME
References
-RFPFR, BYR 2004-006
Download: ML042510589 (117)

Text

Yankee Nuclear Plant Site Historical Site Assessment Yankee Atomic Electric Company Volume I

YANKEE ATOMIC ELECTRIC COMPANY Telephone (413) 424-5261 49 Yankee Road, Rowe, Massachusetts 01367 January 21,2004 BYR 2004-006 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Reference:

(a) License No. DPR-3 (Docket No. 50-29)

Subject:

Historical Site Assessment for YNPS This letter provides the Historical Site Assessment (HSA) in support of the LTP1 for the Yankee Nuclear Power Station (YNPS). The HSA identifies and describes the YNPS site, surrounding environs and pertinent information describing adjacent property. The HSA documents the construction, operational and decommissioning history along with current usage of the YNPS site. The HSA identifies radiological contaminants potentially present at the YNPS site resulting from site operations and the media likely to contain these contaminants. The HSA documents the historical information used to define survey area classifications based on history as described in NUREG-1575 guidance as Class 1, Class 2 or Class 3. The HSA also describes impacted areas and non-impacted areas and the known distribution of radiological contaminants within these areas. The HSA supplements the information provided in the License Termination Plan (LTP) for the YNPS site.

The HSA documents those events and circumstances occurring during the entire operating history of the facility that contributed to the radiological contamination of the site environs above background radiation levels. Information relevant to changes in the radiological status of the site following publication of the HSA will be considered a part of the continuing characterization evaluations. The continuing evaluations include ongoing decommissioning activities, the expansion of the site groundwater investigation and evaluations of subsurface contamination. The results of the ongoing investigations

'into the extent of subsurface contamination will drive continuing remediation and/or mitigation efforts as appropriate.

YAEC Letter to USNRC, "Submittal of YNPS License Termination Plan and Proposed Revision to Possession Only License," dated November 24, 2003, BYR 2003-080.

U.S. Nuclear Regulatory Commission BYR 2004-006, Page 2/2 If you have any questions or require additional information, please contact Mr. Gerry van Noordennen, Regulatory Affairs Manager @ 413-424-2363.

Sincerely, YANKEE ATOMIC ELECTRIC COMPANY Brian C. Wood Site Manager cc: J. Hickman, NRC, Senior Project Manager, NMSS J. Wray, Inspector, NRC Region I (w/o enclosure)

R. Gallaghar, MA DPH D. Howland, MA DEP M. Rosenstein, EPA, Region I W. Perlman, Executive Committee Chair, FRCOG T. W. Hutcheson, Chair, Franklin Regional Planning Board D. Katz, CAN

Yankee Nuclear Plant Site Historical Site Assessment Yankee Atomic Electric Company Volume I

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 Table of Contents 1 ABBREVIATIONS 1-1 2 EXECUTIVE

SUMMARY

2-1 3 PURPOSE OF THE HISTO RICAL SITE ASSESSMENT 3-1 4 PROPERTY IDENTIFICATION 4-1 4.1 PHYSICAL CHARACTERISriCS 4-1 4.1.1 License Holder ' 4-1 4.1.2 Location ' _-_, _' 4-1 4.1.3 Topography ,_- 4-1 4.1.4 Stratigraphy 4-2 4.2 ENVIRONMENTAL SETTING 4-2 5 HISTORICAL SITE ASSESSMENT AND SURVEY AREA DELINEATION  ; 5-1 5.1 APPROACH AND RATIONALE - 1 5.2 BOUNDARIES OF THE SIT E - 5-4 5.3 DOCUMENTS REVIEWED ' 5-5 5.4 PROPERTY INSPECTIONS 5-6 5.5 PERSONNEL INTERVIEWS 5-7 6 HISTORY 6-1 6.1 LICENSING HISTORY 6-1 6.2 REGULATORY INVOLVEMENT 6-2 6.3 FACILITY DESCRIPTION - 6-3 6.3.1 Description of Operations Impacting Site Radiological Status _,, 6-3 6.3.2 Unplanned Events 6-5 6.3.2.1 Unplanned Gaseous Releases ' 6-5 6.3.2.2 Unplanned Liquid Releases - 6-6 6.3.3 Waste Handling Prdcedures 6-6 6.4 ADJACENT LAND USE 6 7 FINDINGS 7-1 7.1 OVERVIEW 7-1 7.2 NON-IMPACTED AREA ASSESSMENT 7-2 7.2.1 Non-Impacted Area Description 7-2 7.2.2 Decommissioning Activities 7-2 7.2.3 Basis of Area Classification 7-3 7.2.4 Occurrence of Anthropologic Radionuclides in the Environmental Background_ 7-3 7.2.5 Evaluation of the Impact of Elevated Releases in Particulate Radioactive Material _ 7-3 7.2.6 Approach and Methodology for Evaluation of the Non-Impacted Area 7-4 7.2.7 Non-Impacted Area Justification Summary 7-4 7.3 POTENTIALLY CONTAMINATED AREAS_ 7-4 7.3.1 Radionuclides of Concern 7-6 7.3.2 Impacted Areas 7-7 7.3.2.1 Buildings, Structures and Open Land Areas Inside the RCA 7-7 7.3.2.1.1 Buildings 7-7 7.3.2.1.2 Yard Structures 7-15 7.3.2.1.1 Open Land Areas 7-26 7.3.2.3 Buildings, Structures and Open Land Areas Outside the RCA .,, 7-32 7.3.2.2.1 Buildings and Structures

• 7-32 7.3.2.2.2 Open Land Areas Outside of the RCS (OOS) 7-41

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YNPS Historical Site Assessment Revision 0 -

YNPS Historical Site Assessment RevisionO 7.4 CONTAMINATED MEDIA 7-54 7.5 RELATED ENVIRONMENTAL CONCERNS 7-54 8 REFERENCES _ 8-1 Table of Tables TABLE 6-1 AORIPIR LIST OF UNPLANNED LIQUID RELEASES_ 6-8 TABLE 7-1 FLOOR AND TOTAL AREA OF BUILDINGS AND FEATURES 7-56 TABLE 7-2 -AREA OF OPEN LAND SURVEY AREAS 7-57 TABLE 7-3 CURRENT RADIOLOGICAL CONDITIONSOF BUILDINGS IN THE INDUSTRIAL AREA 7-58 TABLE 74

SUMMARY

OF RADIOLOGICAL CONDITIONS OF OPEN LAND AREAS (SOF = SUM OF FRACTIONS OF SOIL DCGLS) - 7-60 TABLE 7-5 RADIONUCLIDES OF CONCERN AT YNPS 7-62 Table of Figures FIGURE 7-1 A PRELIMINARY LAND SURFACE IMPACTED AREA BOUNDARIES FIGURE 7-lB PRELIMINARY LAND SURFACE IMPACTED AREA BOUNDARIES (CON'T)

FIGURE 7-2 PRELIMINARY STRUCTURE SURVEY AREA BOUNDARIES FIGURE 7-3 PRELIMINARY LAND SUR FACE IMPACTED AREA CLASSIFICATIONS FIGURE 7-4 LIMINARY STRUCTURE CLASSIFICATIONS FIGURE 7-5 LOCATIONS OF SAMPLES TO DETERMINE BACKGROUND CS-137 IN SOIL FIGURE 7-6 hISTORIC EXPANSION OF RCA BOUNDARIES ii

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 1 Abbreviations AEC Atomic Energy Commission ALARA As Low As Reasonably Achievable ASWS Auxiliary Service Water System BRT Buried Ring Tonnage - Sub-surface Reactor Support Structure (RSS) consisting of poured reinforced concrete.

CFR Code of Federal Regulations cpm Counts Per Minute DCGL Derived Concentration Guideline Level DCGLEMC DCGL for small areas of elevated activity, used with the EMC DCGLw DCGL for average concentrations over a wide area, used with statistical tests DOT Department of Transportation dpm Disintegrations Per Minute DQO Data Quality Objectives DWP Decommissioning Work Plan ECN Engineering Change Notice EPA Environmental Protection Agency FERC Federal Energy Regulatory Commission FCN Field Change Notice GM Geiger-Mueller -

GPS Global Positioning System

\J GWSI Ground Water Site Inventory 1-1

YNPS Historical Site Assessment Revision 0' 0, .'-1" YNPS Historical Site Assessment Revision HSA Historical Site Assessment LLD Lower Limit of Detection LLRWPA Low Level Radioactive Waste Policy Act as Amended MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MCA Multi-Channel Analyzer MDA Minimum Detectable Activity MDC Minimum Detectable Concentration MDCR Minimum Detectable Count Rate NPDES National Pollutant Discharge Elimination System NRC Nuclear Regulatory Commission ORNL Oak Ridge National Laboratory ORISE Oak Ridge Institute for Science and Education PAB Primary Auxiliary Building PCA Potentially Contaminated Area PIC Pressurized Ionization Chamber QA Quality Assurance QAPP Quality Assurance Project Plan QC Quality Control QMP Quality Management Plan RC Release Criterion RCA Radiation Control Area RI/FS Remedial Investigation/Feasibility Study RSSI Radiation Survey and Site Investigation 1-2

YNPS Historical Site Assessment Revision 0 Asessent Sie YNPSHistricl evison SARA Superfund Amendments and Reauthorization Act

.SOP Step Off Pad SSWP Secondary Side Work Plan TRU Transuranics USGS United States Geological Survey HP Health Physics RP Radiation Protection RSS Reactor Support Structure IX Pit Ion Exchange Pit AOR Abnormal Occurrence Report PIR Plant Information Report SIDG Safety Injection and Diesel Building MPC Multi-Purpose Canister VCC Vertical Concrete Cask SFP Spent Fuel Pit or Spent Fuel Pool YAEC Yankee Atomic Electric Company YNPS Yankee Nuclear Power Station 1-3

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YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 KU 2 Executive Summary This Historical Site Assessment (HSA) identifies and describes the Yankee Nuclear Power Station (YNPS) site, surrounding environs, and adjacent property. The HSA documents the construction, operational anid decommissioning history along with current use of the YNPS site.

The HSA identifies radioactive contaminants potentially present at the YNPS site resulting from site operations and the media likely to contain these contaminants. The HSA documents the historical information used to justify survey area classifications, based on history, described in NUREG-1575 guidance, as Class 1, Class 2 or Class 3. The HSA also describes impacted areas and the known distribution of contaminants within these areas and provides justification for delineation of other areas as non-impacted.

The HSA contains two volumes. Volume I is a summary report outlining the methodology used to perform the HSA, a history and current status of the site, and findings resulting from the review of site documents.

Volume II provides the following for each survey area:

• Survey area description,

• Survey area history including kl> - translocation pathways,

- any scoping/characterization activities performed in the area, and

- any decommissioning activities performed in the area.

• Findings, including

- Current status summary

- Classification statemert

• Tables identifying samples collected to date and comparing the results with the site criteria The enclosed CD (Master Reference List) includes reference lists for each of the Volume II survey area sections, many hyperlinked to the actual referenced document. See the electronic file folder entitled, "Reference List" for those documents.

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YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 3 Purpose of the Historical Site Assessment The purpose of this Historical Site Assessment (HSA) is to document a comprehensive investigation that identifies, collects, organizes and evaluates historical information related to the Yankee Nuclear Power Station (YNPS) site. The HSA focuses on open land areas and those structures that will remain at the time of final status survey. The HSA does not address portions of structures or structural systems that are being removed from the site or that will be verified, using existing procedures, to contain no measurable amounts of radioactive contamination (such as plumbing, buried piping and storm and floor drains).

The HSA describes the site physical configuration, identifies the radioactive constituents of site contamination, assesses the migration of contaminants, identifies contaminated media, identifies non- impacted and impacted areas and classifies impacted areas. Guidance contained in NUREG-1575 (MARSSIM), "Multi-Agency Radiation Survey and Site Investigation Manual" (Reference 1) was used to classify site areas as Class 1, Class 2 or Class 3 survey areas. .The HSA supplements the information provided in the License Termination Plan (LTP) for the YNPS site.

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YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 4 Property Identification 4.1 PhysicalCharacteristics 4.1.1 License Holder Yankee Atomic Electric Company (YAEC) is the holder of Possession Only License (POL) No.

DPR-3 (Reference 2).

Yankee Atomic Electric Company 19 Midstate Drive, Suite 200 Auburn Massachusetts 01501 4.1.2 Location Yankee Nuclear Power Station 49 Yankee Road Rowe Massachusetts 01367 The Yankee Nuclear Power Station is located in the town of Rowe, in Franklin County of the Commonwealth of Massachusetts. This site is three-quarters of a mile south of the Vermont-Massachusetts border. The geographical coordinates of the centerline of the reactor containment structure (Vapor Container) are as follows:

Latitude: North 42 degrees, 43 minutes, 42 seconds Longitude: West 72 degrees, 55 minutes, 42 seconds 4.1.3 Topography The location of YNPS is identified on the USGS 7.5 minute quadrangle map Rowe Massachusetts - Vermont (42072-F8-TF-024, 1973, DMA III NW-SERIES V814)

(Reference 3).

4.1.4 Stratigraphy Information related to site stratigraphy was taken from the Environmental Characterization Summary, Yankee Nuclear Power Plant Site, June 2000 (Reference 4). This detailed information may be viewed in Section 4 of the Master Reference List on the CD included with this document.

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3 E-YNPS Historical Site Assessment Revision 0 4.2 EnvironmentalSetting The information pertaining to Geology, Hydrogeology/Hydrology and Meteorology has been obtained from the Decommissioning Environmental Report - pages 3.16 through 3.24 (Reference 5). This detailed information may be viewed in Section 4 of the Master Reference List on the CD included with this document.

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YNPS Historical Site Assessment YNPSHistricl Sie Asessent Revision evison 0 Kt. 5 Historical Site Assessment and Survey Area Delineation 5.1 Approach and Rationale This Historical Site Assessment (HSA) documents those events and circumstances occurring during the history of the facility that contributed to the contamination of portions of the site environs above background levels. Information relevant to changes in the radiological status of the site following publication of the HSA will be considered a part of the ongoing characterization evaluations and decommissioning activities. These ongoing activities include the expansion of the site groundwater investigation and evaluations of subsurface contamination.

The results of the ongoing investigations into the extent of subsurface contamination will drive continuing rem ediation and/or mitigation efforts as appropriate.

The HSA involved collecting, organizing, and evaluating information that described the YNPS' site in terms of physical configuration and the extent to which the site was radioactively contaminated as a result of plant operations and decommissioning activities. The HSA information was used to bound and classify survey areas. The boundaries of the' identified survey areas as depicted in Figures 7-la, 7-lb and 7-2 were selected based on operational history, including recorded significant events, common radiological profiles and, where appropriate, parcel ownership boundaries. The preliminary survey area classifications and sizes are shown in Tables 7-1 for structures and 7-2 for open land areas. Survey areas for structures will be broken into multiple survey units where appropriate in order to meet the survey unit size limitations recommended by NUREG-1575 (Reference 1). All open land survey area boundaries have been sized to meet the NUREG- 1575 size limitation constraints.

The general criteria used to classify the identified survey areas was drawn from the regulatory guidance of NUREG-1575 (MARSSIM) as follows:

Non-impacted Area: Areas where there is no reasonable possibility (extremely low probability) of residual contamination. Non-impacted areas are typically off-site and may be used as background reference areas.

Impacted Area: Any area that is not classified as non-impacted. Areas with a possibility of containing residual radioactivity in excess of natural background or fallout levels. All impacted areas must be classified as class 1, 2 or 3 as described in NUREG-1575.

Class 1 Area: Impacted areas that have, or had prior to remediation, a potential for radioactive contamination (based on site operating history) or known contamination (based on

.previous radiological surveys) above the DCGL. Size limitations are < 100 sq. m. for structures and < 2000 sq. m. for open land areas.

Class 2 Area: Impacted areas that have, or had prior to remediation, a potential for radioactive contamination or known contamination, but are not expected to exceed the DCGL. Size limitations are >100 sq. m. and <1000 sq. m. for structures and > 2000 sq. m. and <

' }

a10,000 sq. m. for open land areas.

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a-YNPS Historical Site Assessment Revision 0 Class 3 Area: Impacted areas that are not expected to contain any residual radioactivity, or are expected to contain levels of residual radioactivity at a small fraction of the DCGL, based on site operating history and previous radiological surveys. There are no size limitations for Class 3 areas.

The collection and evaluation of site radiological information is conducted under approved site procedures. The output of this process is in the form of information generated for each survey area that is used in the preparation of survey plans. Information generated for each survey area contains a detailed description of the survey area, operational history, an evaluation of past and current translocation pathways that have been or continue to be operable, and a description and status of decommissioning work performed. The findings section for each survey area includes an assessment of radiological contaminants, contaminated media, the current radiological status, the results of any subsurface mitigation or remediation efforts and a description of the remaining decommissioning activities.

The general process for integration of the HSA with continuing characterization and Final Status Survey (performed after remediation to confirm that the site release criteria has been met) is shown in the following flowchart.

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YNPS Historical Site Assessment Revision 0 Process for Integrating HSA with Characterization and FSS Review YNPS operational history and identify significant events contributing to contamination of the site.

Establish Survey Area boundaries based on common history.

I Assemble available historical reference documentation into Survey Area packages.

Assign Survey Area Classification.

Publish Historical Site Assessment Document.

Obtain Site-Specific DCGL's.

Update Survey Area packages as decommissioning activities progress. Include results of continuing characterization activities and document progress of remediation/

mitigation of sub-surface survey areas.

End-state of decommissioning attained. All areas below appropriate DCGL's.

Evaluate Data Quality in survey area packages using DQO/DQA process and prepare characterization survey plans.

Obtain additional characterization data if necessary and document turn-over surveys.

Begin Final Status Survey process.

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YNPS Historical Site Assessment Revision Revision 0O 0

YNPS Historical Site Assessment Over the operational history of the YNPS site, the term "remediation'! was often used to refer to any process involving the removal of radioactive media. For the purpose of license termination activities, "remediation" is narrowly defined as efforts specifically conducted to reduce the-quantity or concentration of radioactivity to a level below the appropriate Derived Concentration Guideline Level (DCGL). Other processes may be referred to as "mitigation" or routine decommissioning activities.

5.2 Boundaries of the Site The YNPS site consists of about 2,200 acres on both sides of the Deerfield River in the towns of Rowe and Monroe, in Franklini County, Commonwealth of Massachusetts. Figure 1, "Soil Sample Locations - Site Overview," located in the beginning of Volume II of this document, shows the boundary of the site and plant exclusion area.

The "YAEC Deed Study Project Rowe and Monroe, Massachusetts " dated December 18, 1998, (Reference 6) provides information concerning properties that make up the YAEC site and current abutments.

YAEC or USGen New England, Inc. (USGen) own all of the land located within the licensed site property boundary, and all of the property within the exclusion boundary is under the control of YAEC. The USGen property is generally located along the riverbank and Sherman Reservoir.

The portions of the YAEC industrial area located on USGen property are the circulating water discharge seal pit, the Screenwell Pump House, and the meteorological tower located on peninsula at the northeast corner of the site. USGen also owns that portion of the northeast yard area that fronts Sherman Reservoir and the property outside of the industrial area fence located between Yankee Road and the Deerfield River. A portion of the USGen property is considered impacted by licensed activities and is included in license termination activities.

Two public secondary roads traverse the exclusion area. The first, Tunnel Road, is across the river from the plant, approximately 1,500 feet away at its closest point, and runs north and south along the river connecting the towns of Monroe, Massachusetts and Readsboro, Vermont. The second, Monroe Hill Road, is approximately 2500 feet away from the plant at its nearest point and is located southwest of the plant and runs between the towns of Rowe and Monroe, Massachusetts. During the early site history, a public rail line ran through the industrial area.

This rail line and the associated spur facilitated construction of YNPS and spent fuel shipments.

Currently, there are no rail lines that traverse or are adjacent to the YNPS site.

Most of the site area is wooded with very steep grades on both sides of the Deerfield River.

Features of the site include the Yankee Nuclear Power Station, the YNPS Independent Spent Fuel Storage Installation (ISFSI), the USGen Sherman Station hydroelectric plant, Sherman - -

Reservoir and Dam, the transmission lines running through the site, the Yankee Administration Building and the Yankee Visitor Center (Furlon House).

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YNPS Historical Site Assessment . Revision 0 YNPSHistricl Sie Asessent evison 5.3 Documents Reviewed In performing the YNPS Historical Site Assessment (HSA) the following documents were reviewed:

• License and Technical Specifications

- Technical Specification Changes

- License amendments

• Original Plant Design

- Function and purpose of systems and structures

- Plant operating parameters

- Plant operating procedures

• Original Plant Construction Drawings and Photographs

- Specifications for systems and structures

- Field Changes/as built drawings

- Site Conditions

• Plant Operating History Abnormal Operating Reports (AOR)

- Licensee Event Reports (LER)

- "Plant Information Reports (PIR)

- Radiological Occurrence Reports (ROR)

- Radiological Incident Reports (RIR)

Condition Reports (CR)

- Plant Operating Procedures Regarding' Spills and Unplanned Releases

- Plant Operations Logbooks

- Radiological Environmental Monitoring Program and Radiological Environmental Technical Specification Reports (REMP & RETS)

- Monthly Plant Operations Reports

- Semi-Annual Plant Operations Reports Work Control Documents and Site Modifications

- Job Orders . . .. -

- Plant Alterations - .. -;. .

- Engineering Design Change Requests (EDCR)

-.Plant Modifications Maintenance Requests -.

• Radiological Surveys and Assessments

- ' Radiological surveys performed in support of normal plant'operations and

• maintenance Radiological surveys performed in support of special plant operations and

- Rmaintenance: a s p i ri

-5Radiological assessments performed in response to' radioactive sp ills or events

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a-YNPS Historical Site Assessment Revision 0

- Scoping and characterization surveys performed as part of Decommissioning Plan development

- Remediation support surveys conducted during decommissioning activities

- Surveys conducted under the guidance of NUREG/CR-5849

• The historical evaluations performed for the previously submitted LTP.

• The YAEC Decommissioning Plan

- Decommissioning Work Plans

- Secondary Side Work Plans

- Engineering Change Notifications

- Field Change Notifications

- Temporary Change Requests

• The documented radiological end point of decommissioning activities

• Documentation of remediation area stabilization and restoration activities.

5.4 Property Inspections The YNPS site is at an advanced stage of decommissioning with only those plant systems necessary to support the ISFSI and portions of the site remaining in service (e.g., potable water, sanitary sewers, construction electrical power, fire protection and storm sewers). Plant operations, maintenance and security personnel continue to occupy portions of the site in support of the YNPS site operations and maintenance. Due to the advanced state of decommissioning, these activities have a minimal risk of spreading radioactive contamination. The demolition operations contractor occupies a portion of the site with temporary office spaces from which to conduct the decommissioning/demolition activities scheduled for completion during the current phase of decommissioning. These temporary office spaces will be removed from the site at the completion of this phase of decommissioning. The portion of the site historically identified as the Radiation Control Area (RCA), see Figure 7-6, is posted and restricted for personnel access and radioactive material control. RCA access control is maintained through the Radiation Protection (RP) control point.

Decontamination processes have been performed on certain site structures and systems as part of site decommissioning activities under the site Decommissioning Plan. These processes include application of chemical paint strippers, dry ice (carbon dioxide) blasting, steel shot blasting and mechanical removal techniques (including roto-peen tools, needle guns, reciprocating chipping hammers and jackhammers). In addition) both the east and west storm drain system catch basins have routinely been cleaned of accumulated sediment. Sediment socks are now installed at each catch basin to curtail the build up of sediment in the storm drain system.

Surveys were performed in those areas where decommissioning activities had been completed in accordance with the protocols established under the previously submitted and withdrawn License Termination Plan (Reference 7). Controls were instituted and maintained in most areas to preserve the radiological condition, and routine surveys are performed to verify that the radiological condition of these areas was not adversely impacted by ongoing plant operation, maintenance, or fuel transfer activities. These controls were not instituted for areas in which 5-6

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 FSS activities were placed on hold or where it was not practical to maintain the controls because K.. of decommissioning work activities in adjacent areas.

Decommissioning activities have resulted in the disturbance and/or excavation of soils in certain survey areas. Extensive soil evaluations have been performed to support removal of sub-grade components/systems and site modifications necessary for the construction of the ISFSI and the upgrade of security measures around the spent fuel pool. Piles of excavated soil are located in several areas of the site.

Controls are in place to track the location of these soils from the point of origin (excavation) through temporary onsite storage to final disposition. Disturbed/excavated soils evaluated and verified by sampling and analysis protocols to be non-detectable for radiological constituents (below environmental Lower Limit of Detection LLD level for soils) were used as backfill in some excavated areas. Excavated soils contaminated above a very preliminary DCGL protocol were packaged and disposed of as radioactive waste. This DCGL protocol allowed some soils contaminated above background to be used as backfill in some locations. Retrospectively, the criterion used for the approval of the use of slightly contaminated soils as backfill is lower than the currently proposed DCGL. As these areas are evaluated for survey planning, the backfilled soil results will be evaluated against the soil DCGL for mitigation action.

During the evaluation of survey areas, walk-downs of each area were performed to document the types of survey media remaining or expected to remain at project end-state. The walk-downs also documented the current decommissioning status of the area and identified any potential

' 2 radionuclide translocation pathways that impacted the area or any contiguous survey areas. Such pathways include ongoing decommissioning activities or environmental transport pathways such as sub-surface migration of radioactivity by surface water infiltration, wind, surface water run-off or wildlife.

5.5 PersonnelInterviews At the time of plant shutdown in 1992, personnel interviews were conducted as a part of an exit interview process in order to capture information of historical value. Since that time additional personnel interviews have been conducted and provided additional information on plant operations and practices when additional data was needed or desired relative to condition of the plant or activities performed.

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YNPS Historical Site Assessment Revision YNPS Historical Site Assessment Revision 00 6 History 6.1 Licensing History Yankee Atomic Electric Company is the holder of Yankee Nuclear Power Station Facility Operating License DPR-3 issued under the authority of the Atomic Energy Commission (AEC).

Yankee Nuclear Power Station achieved initial criticality in 1960 and began commercial operations in 1961. The original thermal power design limit of 485 Mwt was upgraded to 600 Mwt in 1963.

On February 26, 1992, the YAEC Board of Directors decided to cease power operations permanently at YNPS. On August 5, 1992 the NRC amended the YNPS Facility Operating License to a possession only status.

The YNPS Decommissioning Plan (Reference 8) was submitted in March 1994 and received NRC approval in October 1996. Subsequently, an in response to updates regulations for decommissioning, Yankee created a Post-Shutdown Decommissioning Activities Report (PSDAR) in 2000 within the Final Safety Analysis Report (FSAR). NRC Draft Regulatory Guide DG-1071 recommends that licensees with approved Decommissioning Plans (D Plans)

"extract pertinent detail from the decommissioning plan and submit a PSDAR update in the format and content specified by [DG-1071]." Based on the NRC draft guidance, Yankee segregated, updated and condensed certain information concerning post-shutdown decommissioning activities in a manner that conforms to the standard format and content of a PSDAR.

In May 1997, Yankee submitted to the NRC for approval a License Termination Plan (LTP) for YNPS, pursuant to 10CFR50.82(a)(9) and in accordance with Draft NUREG/CR-5849 (Reference 9). -

Subsequent changes to NRC regulations with regard to license termination and the adoption of NUREG-1575 (Reference 1) as the final status survey standard among other considerations resulted in the withdrawal of the LTP. Yankee Atomic Electric Companywithdrew this LTP in May 1999. The current LTP.submitted in November 2003 is written to reflect the NUREG-1575 (MARSSIM) final status survey methodology as well as the regulations and regulatory guidance issued since the previous LTP submittal.- -

Decommissioning activities completed as of January 2000 had removed the majority of systems and components not required to support the storage of spent fuel in the spent fuel pit. Detailed planning for the transfer of spent fuel from the spent fuel pit began in February of 2000. In June 2003 the transfer of all fuel and Greater Than Class "C" (GTCC) waste from the Spent Fuel Pit to the ISFSI was' completed. 'A total of fifteen dry 'casks containing spent fuel and one cast containing GTCC were transferred for storage on the ISFI pad. Decommissioning activities resumed during the summer of 2003 with the draining of the SFP and the commencement of -

building demolition.

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YNPS Historical Site Assessment Revision 0 6.2 Regulatory Involvement The NRC monitors YNPS site activities using inspectors from Region I offices to perform quarterly onsite inspections. Periodic calls are also held with NRC headquarters and Region I staff to monitor plant status and decommissioning progress. The NRC is notified of any incidents on site per the existing protocol established with NRC Region I and NRC reporting regulations.

The decommissioning of the YNPS site is also being performed under various Federal, State and local requirements in addition to the NRC regulations. For example, YNPS is subject to OSHA regulations in 29 CFR 1910 and 1926 for worker health and safety protection. Asbestos and lead-based paint handling and removal are also subject to the OSHA regulations, and the EPA regulations in 40 CFR Part 61. State and EPA requirements will be met for PCB paint removal activities. YNPS will also be required to meet the state standards for surface water and groundwater.

The Commonwealth of Massachusetts Department of Public Health also has state radiological remediation standards. Compliance with the state standards is not addressed in this document.

This issue will be addressed in separate correspondence with the Commonwealth.

Permits and approvals from, or notifications to, several State (Commonwealth) and local agencies are required for safety and environmental protection purposes. Some of these are for specific decommissioning activities, and others are for existing YNPS site facilities and ongoing activities that are necessary to support decommissioning. The following is a partial listing of permits and approvals, anticipated or already obtained, for decommissioning activities.

• Air emissions from the burning of diesel fuel are regulated by the Commonwealth of Massachusetts Department of Environmental Protection, Air Quality Control Division

• Non-radioactive liquid effluents are administered by the Commonwealth of Massachusetts Department of Environmental Protection, Division of Water Pollution Control.

• Liquid effluents are controlled under the National Pollutant Discharge Elimination System (NPDES permit) under the EPA and State (Commonwealth) approvals.

• Building permits may be required by the Town of Rowe, Massachusetts, for temporary field office facilities constructed on the plant site to support decommissioning activities.

The Town of Rowe uses the Uniform Building Code for evaluating building permit applications.

• The site make-up water wells are operated under permits from the Commonwealth of Massachusetts Department of Environmental Protection, Division of Water Supply.

• Hazardous waste generation is regulated by the Commonwealth of Massachusetts Department of Environmental Protection, Division of Hazardous Waste. Notification of 6-2

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision the generator status and annual reporting are conducted in accordance with Massachusetts regulations.

• The Commonwealth of Massachusetts, Department of Labor and Industries, Division of Industrial Safety, regulates the installation, removal and encapsulation of friable asbestos-containing materials and lead-based paint. All non-radiological solid waste will be handled and disposed of in accordance with State and local rules and regulations.

• The Commonwealth of Massachusetts, Department of Public Health, Radiological Control Program, and the Vermont State Health Department, Division of Occupational and Radiological Health, are notified in advance of all placarded shipments of radioactive waste. In addition, the Governors of all affected States receive advance notifications in accordance with 10 CFR 71.97, "Advance notification of shipment of nuclear waste."

• Licenses are required for radio communications by the Federal Communications Commission

• PCB paints will be removed from all exposed concrete surfaces as required by the Alternate Method of Disposal Authorization (AMDA) requirements prior to demolition of the structures as authorized by the EPA on October 8, 2002 and subsequent changes thereto.

( 2 6.3 Facility Description, The Yankee Nuclear Power Station operated a Westinghouse Electric Corporation design, four loop, pressurized water reactor, with an original thermal power design limit of 485 MWt. The thermal power design limit was upgraded to 600 Mwt in 1963. The turbine generator, also designed by Westinghouse Electric Corporation was originally rated to produce 167 MWe. The turbine generator design allowed an increase in production capacity to 185 MWe concurrent with the thermal power upgrade (Reference 10).

6.3.1 Description of Circumstances impacting Site Radiological Status Normal plant operations were expected to result in contamination of certain areas of tlr site and these areas were designed to contain such material; however; early in the plant life; certain events and conditions resulted in radioactive material being deposited in other locations. As a result, the plant design and operational procedures evolved to accommodate or eliminate these circumstances. Review of the early operational history of the site drew heavily on the Plant Superintendent's "MonthlyOperating Reports" (Reference -11).

The following events and circumstances listed in chronological order generally contributed to the various aspects of residual contamination found on the site to be dispositioned at decommissioning.

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YNPS Historical Site Assessment Revision 0

• Release of elemental silver and nickel into the reactor coolant due to mechanical wear and corrosion from the initial set of control rods resulted in distribution of radioactive silver in plant systems and on equipment used during the first refueling. [circa 1960's]

• Storage of the refueling equipment and prepared radioactive waste outdoors resulted in distribution of contamination, including radioactive silver, within the RCA yard area.

• Snow removal activities performed in the RCA caused a redistribution of accumulated surface contamination to the areas outside the RCA where snow was relocated.

• Rain falling on the sirface of yard areas in the RCA caused redistribution of the low level contamination into low lying areas in the RCA and into the storm drain system.

• Leaks in the radioactive systems in the Ion Exchange (IX) Pit resulted in contamination of the water in the IX Pit. A defect in the construction of the IX Pit concrete allowed the contaminated water to leak, resulting in contamination of the subsurface soils, asphalt and concrete around the IX Pit and adjoining structures.

• Wear on internal valve components made of stellite resulted in the introduction of wear particles into the reactor primary system. These particles were activated to gamma emitting Co-60 during plant power operations. Some particles associated with fuel fragments were also generated during plant operations. Maintenance on primary system components resulted in the distribution of these activated particles onto tools and equipment. Although not a frequent occurrence, Co-60 particles have been identified and removed during surveys of the yard area. The particles associated with fuel fragments have not been identified in open yard areas but were mostly confined to controlled contamination areas.

• A failure of a check valve allowed a backflow of shutdown cooling water to enter the seal water system resulting in contamination of the normally clean seal water system up to and including the vent port on the PAB roof.

• Out of doors decontamination facilities (North and South decontamination pads) resulted in contamination of the soils around the pads.

• The repair of a damaged reactor cooling pump motor on the normally clean turbine deck resulted in contamination of the turbine building generally and on the turbine deck and control room specifically.

• In the mid 1970s YNPS converted to zirconium clad fuel pins from stainless steel. Some of the zirconium fuel pins failed in the reactor due to water jetting. This resulted in a release of fuel pellets directly into the reactor coolant system. This event changed the isotopic mix within the Reactor Coolant System. In particular, detectable quantities of fission products such as Cs- 137 and Cs- 134 were dispersed throughout the primary side plant systems and the fuel handling facility for the first time in the plant operating history.

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YNPS Historical Site Assessment Revision 0 K2

• During a refueling outage in 1981, while relocating the reactor head to its outside storage location, the reactor head made contact with the wall above the equipment hatch in the Vapor Container. The impact dislodged particulate radioactivity adhered to the under side of the reactor head. This incident resulted in contamination of the RCA yard area under and around the equipment hatch.

• Construction of the original PCA storage facility included a PVC drainpipe that connected the PCA storage building to the Waste Disposal Building. The PVC pipe joints failed allowing liquid to flow from the drainpipe into the surrounding soil.

• The use of an underwater plasma torch to section the reactor internals resulted in the release of highly radioactive cutting debris into the shield tark cavity, shield water. This changed the radionuclide mix of the residual contamination in the shield tank cavity and, to a certain extent, in the Spent Fuel Pit.

6.3.2 Unplanned Events A comprehensive review of all recorded events documented as having occurred outside the normal operational condition was performed to capture those events that contributed to the contamination of the site. These events were typically documented in the format suitable for reporting to regulatory authorities such as Abnormal Occurrence Reports (AOR's), submitted K. during the early site history, Plant Incident Reports (PIR's), Licensee Event Reports (LER's), and at present, Condition Reports (CR's). Where available, the information in these reports was supplemented by supporting documentation concerning the events in the form of plant memos and radiological survey data.

6.3.2.1 Unplanned Gaseous Releases Over the lifetime of the plant, a number of unplanned gaseous release events occurred. Short descriptions of these gaseous events as described in AOR/PIRILER's are documented in the Appendix A- 1. These gaseous release events described in Appendix A- 1 did not contribute in a significant manner to the residual contamination at YNPS.

A detailed study of the particulate releases during the entire operating history of YNPS is used to justify the ndn-imp'acted'tau~S fora majority of the YAEC-owned property (Reference 15). This study considered the impact of the particulate emissions 'from the primary vent stack as well as those from the incinerator. The batch incinerator emissions were'considered to wrdioactiv-e-w'aste be of negligible impact when compared tothe particulate releases from the'Primary'Vent Stack' (PVS) over the life of the plant. A careful review 6f the PVS 'discharges did not reveal any unmonitored particulate component that could have significantly contributed to the long-term contamination of the site or its environs.

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YNPS Historical Site Assessment Revision 0 6.3.2.2 Unplanned Liquid Releases Several AOR's and PIR's reviewed documented unplanned liquid releases that resulted in contamination of the site grounds, buildings and subsurface locations. When subsurface contamination investigations were not performed due to inaccessibility or were not completed to the level suitable for license termination, these locations are targeted for continuing characterization investigation. Table 6-1 provides a listing of the events identified to have resulted in contamination of the site. Appendix A-2 provides a brief summary of each event based on documentation prepared at the time of the incidents, and an assessment of which survey areas were impacted by the events.

6.3.3 Waste Handling Procedures The Technical Specifications of the YAEC license described the processes for handling radioactive waste generated as a byproduct of plant operation. The waste handling procedures were intended to contain, adequately treat and dispose of these radioactive byproducts. The waste disposal system used several basic processes to treat and dispose of this material (Reference 10). They are as follows:

• Retention in storage to allow natural decay of short lived radioactive isotopes

• Filtration and ion exchange to remove radioactive constituents from liquids

• Evaporation to concentrate radioactive constituents

• Filtration by charcoal and high efficiency particulate air filters for gaseous discharge.

• Dilution of low.activity liquid and gaseous discharges Spent fuel was removed from the site and shipped to a reprocessing facility in the early years of plant operation. The last spent fuel shipments from YNPS occurred in 1971. Spent fuel generated after this time remained on site in the SFP and has been transferred to the YNPS Independent Spent Fuel Storage Installation (ISFSI).

6.4 Adjacent Land Use The following paragraphs describe the features and uses of land within 5 miles of the plant.

Included is a summary of the population centers within 10 miles of the YNPS site.

Maior Bodies of Water: In addition to Sherman Pond and the Deerfield River (including branches and brooks feeding it), other major bodies of water are located within 5 miles of the YNPS site. These include: Sadawga Pond (184 acres), Shippee Pond (25 acres), North Pond (17 acres), and Clara Lake (12 acres) in Whittingham, Vermont; Howe Pond (42 acres) in Readsboro, Vermont; and Bear Swamp Upper Reservoir (128 acres) and Pelham Lake (89 acres) in Rowe, Massachusetts.

Industry: There are no exclusively commercial areas within 5 miles of the plant. The only industry within the area is the YNPS and USGen New England's hydroelectric stations. USGen 6-6

YNPS Historical Site Assessment I, . Revision 0 YNPS Historical Site Assessment Revision 0 has five powerhouses within 5 miles of YNPS. There are three stations as a part of the Deerfield K~ J River Project. They are the Harriman, Sherman, and No. 5 Stations. In addition the Bear Swamp and Fife Brook stations are a part of the Bear Swamp Pumped storage facility.

Public Lands and Conservation Areas: There are several public lands/conservation areas within 5 miles of the YNPS site. These areas offer a variety of recreational opportunities including fishing, hunting, boating, swimming, picnicking, and hiking.

Schools: There are two schools within 5 miles of the plant: Rowe Elementary located about 2.5 miles southeast of the site on Pond Road in Rowe, Massachusetts and Readsboro Central School, located off of Route 100 near the center of Readsboro, Vermont. '

Farns: Information was collected by YAEC to document the nearest garden and milk animal locations. These locations include farms and private gardens or dairying locations. -

Water Supplies: Water supplies within the Deerfield River Drainage Basin, including the entire area within 5 miles of the plant, generally consist of private wells . The only communal source, of water within 5 miles of the plant site is'Phelps Brook, which services some of the residents of,-

Monroe, Massachusetts. Beyond 5 miles, downstream there are two small water supply wells:

servicing local private developments: the Deerfield River Club and Heath' Stage Apartments in:

Charlemont, Massachusetts. Still further downstream, 'the' closest public Water supply wells,-

Stillwater Springs, are in the town 6f Deerfield, 20 to 25 miles south of the -YNPS. -Stillwater Springs has a safe yield of about'120,000 gallons perfday.' This well field is immediately adjacent to the Deerfield River. Another supply well, the Deerfield -Well Field, off of Route 116, has been closed due to contamination from nearby agricultural uses.- The Quabbin Reservoir, serving the greater Boston area, is 35 to 40 miles southeast of the YNPS.

Population: The population within 10 miles of the site is estimated to be 39,300 people and includes 17 municipalities in two states. 'In general, the area is rural, with North Adanms, MA, being the most populous' municipality.'

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M-YNPS Historical Site Assessment Revision 0 Table 6-1 AOR / PIR List of Unplanned Liquid Releases Impacted Survey AOR/ Description Area PIR #

NOL-2 /NOL-5 61-15 Radioactive Spill - 9/20/61 NOL-,1/NOL-2 and 63-12 Shield Tank Cavity Fill Water Spill - 9/18/63 NSY-2 OOL-1 63-17 De-watering Pump Packing Leakage - 10/8/63 AUX- 1 64-08 Seal Water Tank Spill - 9/3/64 NOL-l/NSY-2 64-13 IX Pit High Level - Leakage Coming Up through Pavement'-

10/3/64 SFP-1/NOL-1 66-07 Spent Fuel Pit Water Spill - 9/27/66 OOL-5/OOL-6 66-08 Abnormal Activity in Storm Drain - 9/27/66 NOL-1/OOL-1 66-09 Hose Failure - 11/1/66 NSY-7 68-01 Waste Hold-up Tank Moat Spill - 1/16/68 NOL- 1 thru 6 75-07 Yard Area Contamination - 7/16/75 NOL-2 77-16 Service Building Radioactive Sump Transfer Line Puncture -

12/21/77 NOL-2/NSY-2 80-09 Resin Spill - 8/6/80 NOL- 1/NOL-6 81-09 Contamination of Yard Area During Rx Head Removal - 5/15/81 OOL-12/OOL-13 WST- l/WST-2 84-16 Drain Pipe Failure' - 9/10/84 NOL-1 94-03 Leakage from Frozen Fuel Chute Dewatering Line 2/17&18/94 NOL- 1 94-09 NST Tell-Tales/Fuel Chute Dewatering Line 2/23/94 1Routine leakage points, paths for subsurface contamination.

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YNPS Historical Site Assessment Revision 0 7 Findings 7.1 Overview An in-depth assessment of the operational history performed during compilation of the HSA was used to bound and classify the survey areas in accordance with the guidance of NUREG-1575. Generally, of the approximately 2200 acres of land thnt comprise the YNPS site, less than 30 acres were'impacted by plant operations. The preliminary boundaries of the impacted areas are depicted in Figures 7-la, 7-lb and 7-2. Tables 7-1' and 7-2 list the survey area dimensions and their classifications in a tabular format.

Impacted area classifications are shown in Figures 7-3 and 7-4 on a color-coded site map.

The majority of the site property (approximately 2170 acres) is considered to be non-impacted by YNPS operations. The site property lines defining the outer boundaries of the non-impacted area (NIA) are shown relative to the size of the site industrial area in Figure 7-5. A detailed assessment of the condition of the NIA and the justification for the assignment of a non-impacted status is provided in Section 7.2.

Of the approximately 30 acres that are impacted, most are only minimally impacted and, as such, are classified as a group of Class 3 open land survey areas arranged around the perimeter of the impacted area. These Class 3 open land surwy areas completely surround the site industrial area and embrace the furthest reasonable extent of potential pathways of site-related radioactivity into the surrounding environment. The Class 3 open land survey areas identified in Figure 7- lb are isolated from the other impacted areas; however, these areas received material, primarily soil, from plant locations that were impacted.

The Class 2 open land survey areas that abut the Class 1 open land survey areas may have areas of detectable activity; however, these areas are not expected to yield measurements of radioactivity in excess of the DCGL. This creates a buffer zone that will receive a higher level of assessment based upon its likelihood to contain radioactivity at some fraction of DCGL.

Class 1 open land survey areas are identified based upon historical information indicating the potential presence of radioactivity at levels greater than DCGL. These areas are mostly. located within the boundaries of the historical RCA. Boundaries of the RCA are shown on Figure 7-6.

Table 7-4 summarizes the radiological conditions of open land afeas, the associated MARSSIM classifications and the total land area by survey area. The radiological condition of each area is expressed as the minimum, maximum and mean of the sum of fractions of the interim DCGLs for soils based on the analytical results of actual samples of survey media obtained from each survey area. These samples were collected as part of the land area survey performed under the guidance of NUREG/CR5849 during 1997/1998. The interim DCGLs were calculated in support of the LTP development process and used here as a comparison basis. Prior to the final completion of this HSA, 7-1

0-YNPS Historical Site Assessment Revision 0 the final proposed DCGLs were completed. A discussion of this comparison is presented later in Section 7.3 of this HSA.

Subsurface soils and subsurface structures/systems located within or that traverse an open land survey area will be evaluated separately as part of the continuing characterization and subsurface classification process described in Section 2.6 of the Yankee Nuclear Plant Site License Termination Plan (LTP), Revision 0 (Reference 20). If subsurface areas or structures are impacted they will be removed, remediated or mitigated as appropriate until the clean up criteria have been met.

All YNPS structures associated with the site are considered impacted to some extent by plant operations and are located within a designated impacted open land survey area.

Few of the structures on site will remain after the current phase of decommissioning is complete.

The majority of the structures will be demolished to grade leaving reinforced concrete floor slabs, foundations and sub-grade structures. The floor slabs and adjoining interior walls may be included within a given survey unit dependent on surface area size limitations. Table 7-1 summarizes the structure survey area classifications and the total interior area to be surveyed. A summary of the current radiological conditions of structures and buildings tabulated by suney area is presented in Table 7-3.

7.2 Non-Impacted Area Justification 7.2.1 Non-impacted Area Description The majority of the land surrounding the industrial area of the site is classified as non-impacted in accordance with MARSSIM criteria. This portion of the site is open land consisting of approximately 2170 acres. The non impacted land surrounds the industrial area. The non-impacted area is bounded on the east and south by Monroe State Forest, on the southeast by USGen property, on the west by Readsboro Road (with the exception of an 89 acre plot on Kingsley Hill Road), and on the north by the Massachusetts/Vermont state line. The non- impacted area was not involved in plant operations and consists mostly of rugged terrain which is forested and undisturbed.

Power lines traverse the area in a northeast by east direction (see Figure 7-5). The general site is shown on USGS map Rowe, Massachusetts-Vermont (Reference 3).

7.2.2 Decommissioning Activities There were no decommissioning or remediation activities performed in the non-impacted area. Most of the area is forested. The power line right-of-way is cleared of trees.

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YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision 7.2.3 Basis of Area Classification The basis for the non- impacted classification of this survey unit is that there is no reasonable possibility of residual contamination based upon the following (References 13, 14 and 15):

• Samples collected as part of the Radiological Environmental Monitoring Program (REMP) throughout the plant's operational and post-operational history show no evidence of any significant radiological impact due to plant operations;

• Aerial photographs from 1966, 1970, 1974, 1980, 1981, 1982, 1989, and 1990 show no evidence of soil disturbance;

• A conservative evaluation of the potential impact of particulate effluents to soils outside of the industrial area using a Gaussian dispersion/deposition model substantiates the conclusion that this source of plant-derived radioactive material would be expected to contribute (at a maximum) a very small fraction of the DCGL.

Beyond the impacted area boundary, concentrations of plant-derived radioactive material would be non-detectable and indistinguishable from background.

• A statistical comparison of soil sample analytical data from the non-impacted are and.

an environmentally equivalent reference area (unaffected by plant releases) was performed (Reference 13).

7.2.4 Occurrence of Anthropogenic Radionuclides in the Environmental Background According to the National Council on Radiation Protection and Measurements (References 16, 17 and 18),'radionuclides present in the environmental background are both naturally occurring and man-made. Carbon- 14 is introduced cosmogenically and by the atmospheric testing of nuclear weapons. Tritium is also introduced cosmogenically and through atmospheric detonation of nuclear weapons. Cesium-137 anid Strontium-90 are fission products that occur in the environment as a result of atmospheric nuclear weapon detonations.

7.2.5 Evaluation of the-Impact of Elevated Releases of Particulate Radioactive Material . -

YRC-1 178 (Reference 15) provides a conservative evaluation of the deposition of particulate activity in gaseous effluents over the operating'history of YNPS. The study examined Semi-Annual Effluent Reports and Monthly Operating Reports that contain the total activity, by radionuclide, released from the plant in airborne particulate form. This study substantiates the fact that the non-impacted area was not impacted by particulate releases from the Primary Vent Stack.

'7-3

a-YNPS Historical Site Assessment Revision 0 7.2.6 Approach and Methodology for Evaluation of the Non-Impacted Area Thirty (30) surface soil samples were collected from the non-impacted area in August of 1998. The location of each sample point and the general location of the plant site relative to the survey area are presented in Figure 7-5. Sixty surface soil samples were also obtained (in 1996) from a selected reference area beyond the boundaries of the YNPS-owned property.

Two types of statistical tests were performed to evaluate whether the soils from the non.

impacted area contain excess Cs- 137 relative to the soil samples from the reference area.

These analyses are presented in Reference 13. The Student t-test was used to compare the mean values of the two data sets. The second test was a single-tailed Fisher's "F-Test" of the variances of the Cs- 137 concentrations in the reference area and the non-impacted area. This comparison is also known as the Analysis of Variance or the Variance Ratio. The test compares the variances of both data sets.

Additional statistical analyses were performed on the shapes of the sample distribution to provide additional evidence that these two distributions may have the same source.

These were tests for skewness and normality. These tests indicated that the parameters for the data sets are alike.

7.2.7 Non-impacted Area Justification Summary The classification of the area described above as non- impacted is based upon historical photographs, results of Radiological Environmental Monitoring Program surveys, particulate gaseous effluent deposition modeling and a statistical analysis of Cs- 137 soil concentrations relative to a set of background reference areas (Reference 13).

7.3 Potentially Contaminated Areas The summary assessments provided in section 7.2.2 include a description, key elements of the history, contaminated media and an evaluation of the principle radionuclides expected to be present in the area. Detailed information for each survey area is found in appendices titled with survey area designators (e.g., AUX-0 1) are presented as appendices to the HSA. These detailed survey area descriptions and operational histories also include the current decommissioning status and a description of the work remaining to be done to attain the anticipated end-state. A survey area classification statement is provided at the end of each detailed assessment.

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YNPS Historical Site Assessment Revision 0 The classifications assigned are based on historical activities performed in these survey areas. These classifications are substantiated by the large quantity of scoping data available in the form of soil sample analyses and survey data. Summaries of the survey and soil sampling data shown in Tables 7-3 and 7-4 are compiled from information in the detailed survey area reports in the appendices to the HSA.

The data provided in Table 7-4 for the open land areas provide comparisons to interim soil DCGLs in the last three columns as sums of the fractions (SOFs) using the unity rule relationship as:

SOF =E C DCGL, As seen in Table 7-4, three values of SOF are provided for each survey area, the minimum value (min), the maximum value (max), and the mean value (mean) for all sample data available for this comparison. In this calculation, only positively measured values were included.

In this comparison, all soil sampling data taken in each survey area listed from the 1997/1998 sampling in support of the survey conducted in accordance with NUREG/CR5849 was evaluated using this unity rule. In the context of MARSSIM surveys, this sample data is considered scoping data. The comparison in Table 7-4 applies the interim soil DCGL values that were available during the preparation of the LTP. As this HSA became completed, a more current set of soil DCGLs (i.e. proposed final DCGLs) became available.

The following table is a comparison of the interim and proposed final soil DCGL values.

As indicated in this comparison, the interim and proposed DCGL were all within a factor of two (with the exception of H-3, not included in previous soil analysis) with the majority of the values within approximately 25%.

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YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision Interim Proposed  % of Nuclide DCGL* Final DCGL** Interim DCGL H-3 8.527E+02 3.7E+02 43.4%

C-14 1.123E+01 5.5E+00 49.0%

Mn-54 2.166E+0 I N/A Fe-55 3.620E+04 2.9E+04 80.1%

Ni-59 4.007E+03 N/A Ni-63 1.464E+03 8.1E+02 55.3%

Co-60 4.838E+00 4.OE+00 82.7%

Sr-90 2.680E+00 1.7E+00 63.4%

Nb-94 8.532E+00 7.2E+00 84.4%

Tc-99 2.528E+01 1.4E+0 1 55.4%

Ru- 106 6.821E+01 N/A Ag- 108m 8.521 E+00 7.3E+00 85.7%

Sb- 125 3.773E+01 3.2E+01 84.8%

Cs- 134 6.706E+00 5.OE+00 74.6%

Cs.137 1.224E+0 1 8.6E+00 70.3%

Eu- 152 1.206E+01 1.0E+01 82.9%

Eu- 154 1.1 13E+01 9.5E+00 85.4%

Eu- 155 4.670E+02 4.OE+02 85.7%

Pu-238 5.166E+01 3.3E+01 63.9%

Pu-239 4.591E+01 3.OE+0 I 65.3%

Pu-241 1.581E+03 9.8E+02 62.0%

Am-241 4.435E+01 2.9E+01 65.4%

Cm-243 4.55 1E+01 3.2E+01 70.3%

• YA-CALC-00-002-03

• • YA-CALC-01 -002-03 In examining the SOF values on Table 7-4, it is evident that the use of the interim DCGLs would not result in any reclassifications for all class 2 and 3 survey areas given the reasonably close agreement between these DCGLs and the low SOF values shown for the survey areas. Therefore, modification of the comparison basis to the final proposed DCGLs is not needed since this data provides ample substantiation of the classification performed only by historical basis.

7.3.1 Radionuclides of Concern An analysis has been performed to determine the radionuclides that have potential dose significance at license termination (Reference 19). This analysis has used three sources of radionuclide data to assure that all significant nuclides associated with plant operations are identified. The sources are selected Part 61 analyses representing several media types spanning a time period from pre-shutdown to the present, radionuclide distributions identified in the YNPS Decommissioning Plan (Reference 9) and source tenn 7-6

YNPS Historical Site Assessment Revision 0 information from NRC published reports. The significant radionuclides identified from the Part 61 analyses encompassed those identified from the latter two sources. The final listing of potentially significant radionuclides is shown on Table 7-5.

7.3.2 Impacted Areas 7.3.2.1 Buildings, Structures and Open Land Areas Inside the RCA The following designations are used in identifying survey areas inside of the RCA (Figures 7-3 and 7-4):

AUX Primary Auxiliary Building BRT Vapor Container Support Structure (sub-surface)

NOL Open Land Areas Inside the RCA NSY Yard Structures Inside the RCA WST Waste Disposal Building Summary individual survey area assessments are described in Appendix B. In general all survey areas within the confines of the historical RCA (Figure 7-6) have been assigned a Class 1 status. The exceptions are NSY-1O and NOL-07, which are the ISFSI Pad and the open land area immediately surrounding this structure. The area was excavated to prepare a suitable surface for the new concrete pad structure. The soils removed from this excavation were evaluated by composite sampling and found to contain only naturally occurring radionuclides.' The pad and surrounding land have been assigned a Class 3 status pending further evaluations following the final disposition of the spent fuel containers.

7.3.2.1.1 Buildings Old PCA Warehouse (WST-01) ,

==

Description:==

WST-OI is a concrete block structure constructed on a reinforced concrete.

foundation. It contains a reinforced concrete tank/tub fitted with a drain that connects to the floor drain and continues to the Waste Disposal Building ash do-watering sump. It:.:

also had a locally-controlled ventilation system located in the northeast corner of the structure.

History: WST-01 was constructed for use as an equipment decontamination and storage facility. It was subsequently converted to a contaminated area used for radioactive material storage only. It was later decontaminated and is now used as a hazardous and mixed waste storage location. The decontamination tub was generally used for items considered heavily contaminated. These include control rod dash-pots and other, components of moderate size from the primary systems. The glue in the joints ofthe drain line from this tub failed to hold over time and the use of the tub was discontinued.

This drain line was partially remediated in 1984 during construction of the Radwaste Warehouse (WST-02). The area directly under the tub remains to be investigated.

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U-_

YNPS Historical Site Assessment Revision 0 Contamination:

I. Radionuclides Potentially Present: The primary radionuclides of concern for survey area WST-01 are Co-60, Cs-137, Ag-108m, Ni-63, Sr-90 and H-3.

2. Media: Reinforced concrete structure (slab), sub-floor soil, sub-surface structures

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-floor soils Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in WST-O include:

• Closing of the tank/tub and floor drain system to inputs.

• Removal of the local ventilation system.

• Decontamination activities

• Painting of the structure interior

2. Planned: Planned decommissioning activities for the WST-01 include demolition of walls to elevation 1035' 6".

3. Anticipated End State Configuration: The end state configuration of WST-01 is anticipated to include:

• Reinforced concrete structures (slab)

• Subsurface concrete structures (foundations)

• Sub-floor soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area WST-01 is identified as a Class 1 Area.

Radwaste Warehouse (WST-02)

==

Description:==

WST-02 is a steel frame and concrete block structure constructed on a reinforced concrete foundation. WST-02 is bounded by WST-04 and WST-03 on the north; NSY-07, NOL-03 and WST-01 on the east; NOL,04 on the south; and NOL-05 on the west.

History: WST-02 was constructed for use as a radioactive waste storage facility.

However, it is normally maintained as a non-contaminated area. Contaminating events have occurred in WST-02.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area WST-02 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete surface structures, subsurface structures, systems and subsurface soil.

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YNPS Historical Site Assessment Revision 0 Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in WST-02.

2. Planned: Planned decommissioning activities for the WST-02 include demolition of walls to elevation 1035'-6."

3. Anticipated End State Configuration: The end state configuration of WST-02 is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area WST-02 is identified as a Class 1 Area.

Waste Disposal Building (WST-03)

==

Description:==

WST-03 is a steel frame and concrete block structure constructed ona reinforced concrete foundation. WST-03 is bounded by NOL-05 on the north, NSY-07 on the east, WST-02 on the south, and WST-04 on the west.

History: WST-03 was constructed for use as a radioactive waste processing and storage facility. It was normally maintained as contaminated area. Contaminating events have occurred in WST-03.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area WST-03 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil and subsurface structures.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete surface structures, subsurface structures, systems and subsurface soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in WST-03 include:

• Removal of all waste processing systems

• Removal of floor drains.

• Removal offloors

• Removal ofsub-floor soils

• Backfill of soil removal areas.

2. Planned: Planned decommissioning activities for the WST-03 include demolition of walls to elevation 1035'-6".

3. Anticipated End State Configuration: The end state configuration of WST-03 is anticipated to include:

• Surface concrete structures (slabs)

• Subsurface concrete structures

• Subsurface soil.

7-9

U-YNPS Historical Site Assessment Revision 0 Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area WST-03 is identified as a Class 1 Area.

Waste Compactor Building (WST-04).

==

Description:==

WST-04 is a steel frame and concrete block structure constructed on a reinforced concrete foundation. WST-04 is bounded by NOL-05 on the north, WST-03 on the east, WST-02 on the south, and NOL,05 on the west.

History: WST-04 was constructed for use as a radioactive waste processing and storage facility. It was normally maintained as non-contaminated area. Contaminating events have occurred in WST-04.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area WST-04 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil and subsurface structures.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete surface structures, subsurface structures, systems and subsurface soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in WST-04 include:

• Removal of all waste processing systems

2. Planned: Planned decommissioning activities for the WST-04 include demolition walls to elevation 1035'-6".

3. Anticipated End State Configuration: The end state configuration of WST-04 is anticipated to include:

• Surface concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area WST-04 is identified as a Class I Area.

Service Building RCA (SVC-02)

==

Description:==

SVC-02 is bounded by SVC-01 and SVC-03 on the north, SVC-03 and OMB-04 on the east, OOL-12 and OOL-01 on the south and NSY-01 and TBN-01 on the west. SVC-02 consists of a steel frame and concrete block structure. Sink and floor drain located in SVC-02 are contaminated and connect to the Liquid Waste Disposal System in NSY- I 1.

7-10

YNPS Historical Site Assessment Revision Revision 00 YNPS Historical Site Assessment History: The systems present and the processes performed in SVC-02 did involve radioactive materials. Contaminating events did occur in SVC-02. SVC-02 has served as the primary entrance and egress from the RCA during most of the plant history.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area SVC-02 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in SVC-02 include:

. - Removal of equipment.

2. Planned: Planned decommissioning activities for the SVC-02 include demolition of walls to elevation 1022'-8".

3. Anticipated End State Configuration: The end state configuration of WST-04 is anticipated to include:

• Surface concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history and as a result of the decommissioning activities performed to date, survey area SVC-02 is identified as a Class 1 Area.

East Primary Auxiliary Building (AUX-01)

==

Description:==

AUX-Ol consists of that portion of the PAB designed to contain the radiological constituents resulting from operation of the primary (radioactive) systems of the plant. The design of the AUX-01 portion of the PAB provided for collection and control of radioactive liquid and gaseous spills or releases 'that occurred within this portion of the PAB. All areas within AUX-01 have floor'drains that channel liquids to the radwaste system and are ventilated through the Primary Ventilation'Stack. AUX-01 is bounded by NOL-01 on the north, NSY-02 on the east, NOL,02 on the south and AUX-02 on the west. The structure is constructed of reinforced concrete.

History: The PAB was identified as a contaminated area shortly after the initial criticality of the YNPS reactor, as a result of a pipe leak. 'Over the operating history of the YNPS  !

this portion of the plant has been'maintained as a contaminated area.

7-11 '

YNPS Historical Site Assessment Revision 0 Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area AUX-01 are Co-60, Cs- 137, Ag- 108m, Sr-90, Fe-55, Ni-63, Am-241, and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: The decommissioning activities performed have removed all radiologically contaminated piping, pumps, tanks, and other system components from AUX-01. In addition concrete surfaces have been de-contaminated via surface removal techniques.

2. Planned: Planned decommissioning activities for the PAB structure include demolition of the west, north and east walls to grade elevation on the north side of the building and demolition of the south wall to grade elevation on the south side of the building. k

3. Anticipated End State Configuration: The anticipated end state configuration consists of reinforced concrete floor slabs, foundations, surface structures below the north grade elevation and the south wall up to the south grade elevation (a difference of about 13 feet) and adjacent sub-surface soils.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area AUX-01 is identified as a Class I Area.

West Primary Auxiliary Building (AUX-02)

==

Description:==

AUX-02 consists of that portion of the PAB that was not designed to contain portions of the primary (radioactive) operating systems of the plant. The design of the AUX-02 portion of the PAB did not provide for collection and control of radioactive liquid and gaseous spills or releases, if they occurred within this portion of the PAB. All areas within AUX-02 had floor drains that channeled liquids to the storm drain system.

These spaces are not ventilated through the Primary Ventilation System. AUX-02 is bounded by NOL-01 and NOL-06 on the north, AUX-01 on the east, NOL-05 on the south and NOL-06 and NSY-03 on the west. The structure consists of a steel frame and block wall construction.

History: The AUX-02 area of the PAB was identified as contaminated as a result of a cross-contaminating event where water spilled from the seal water system vent.

Contamination of AUX-02 also occurred when the Safety Injection Tank heating system pump leaked resulting in contamination of the floor and floor drains in the lower level of the PAB. Over the operating history of the YNPS, this portion of the plant has been decontaminated, in order to maintain it as a non-contaminated area.

7-12

YNPS Historical Site Assessment YNPS Historical Site Assessment Revision 00 Revision Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area AUX-02 are Co-60, Cs- 137, Ag-108m, Sr-90 and H-3.,-

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: All piping, pumps, tanks, and other system components have been removed from AUX-02 with the exception of the Roof Drain System. In addition concrete surfaces have been de-contaminated via surface removal techniques.

2. Planned: Planned decommissioning activities for the AUX-02 structure include demolition of the west, north and east walls to the north grade elevation and the demolition of the south wall to the south grade elevation (similar to AUX- 01).

3. Anticipated End State Configuration: The anticipate end state configuration consists of reinforced concrete floors, foundations, surface structures below the north grade elevation and the south wall below the south grade elevation including adjacent sub-surface soils.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area AUX-02 is identified as a Class 1 Area.

Spent Fuel Pit (SFP-01)

==

Description:==

SFP-01 is a steel frame and metal panel structure built atop the reinforced concrete spent fuel pool. SFP-01 is bounded by NOL,0l on the north, SFP-02 on the east, NSY-02 on the south, and NSY-09 and NOI:01 on the west.

History: SFP-01 was constructed for use as a wet spent fuel storage facility. It was normally maintained as contaminated area. Contaminating events have occurred in SFP-01 that resulted in contamination of the outside of the structure. This survey area also includes appurtenances such as the Fuel chute lower lock valve assembly ("Woodchuck hole") and the fuel chute de-watering pump pad.-

Contamination

1. Radionudlides Potentially Present: The primary radionuclides of concern for survey area SFP-0l are Co-60, Cs-137, Ag-108m, Sr-90, C-14, Fe-55, Am-241, Pu-238, 239/240,241'and H-3. ,

2. Media: Reinforced concrete, surface soil, sub-surface soil and subsurface structures.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete surface structures, subsurface structures, systems and subsurface soil.

7-13

YNPS Historical Site Assessment Revision 0 Decommissioning/Decontamination Activities

1. Performed: The fuel transfer chute has been isolated from the VC. The pit has been drained and a preliminary decontamination has been performed to allow removal of the stainless steel pit liner.

2. Planned: Planned decommissioning activities for the SFP-01 include demolition walls to elevation grade. Continued investigation of the extent of the residual concrete contamination may result in complete removal of this structure.

3. Anticipated End State Configuration: The end state configuration of SFP-01 is currently anticipated to include:

• Surface concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area SFP-01 is identified as a Class 1 Area.

New Fuel Vault (SFP-02)

==

Description:==

SFP-02 is a concrete block structure built on a reinforced concrete foundation. SFP-02 is bounded by NOLl0 on the north and the east, NSY-02 and NOL-02 on the south, and SFP-01 on the west.

History: SFP-02 was constructed for use as a new fuel storage facility. It was normally maintained as contaminated area.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area SFP-02 are Co-60, Cs- 137, Ag- 108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil and subsurface structures.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete surface structures, subsurface structures, systems and subsurface soil.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in SFP-02.

2. Planned: Planned decommissioning activities for the SFP-02 include demolition of walls to elevation 1022'-8".

3. Anticipated End State Configuration: The end state configuration of SFP-02 is anticipated to include:

• Surface concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area SFP-02 is identified as a Class I Area.

7-14

YNPS Historical Site Assessment Revision 0 7.3.2.1.2 YardStructchres VC/Reactor Support Structure (BRT-01)

==

Description:==

BRT-01 is enclosed by NOL-01 on the east and NOL-06 on the west. BRT-01 consists of reinforced concrete structures remaining after demolition of the Lower Pipe Chase, the Fuel Transfer Chute Support, Vapor Container (VC) and the Reactor Support Structure (RSS). This includes the following:

• The two, reinforced concrete RSS leg bases that protrude out of the RSS mat foundation.

• The six, reinforced concrete RSS leg bases that protrude out of the RSS ring beam foundation.

• The sixteen, reinforced-concrete bases that support the VC legs

• The Lower Pipe Chase Support and foundation.

• The Fuel Transfer Chute Support and foundation.

The VC formerly contained'the primary'reactor systems such as the reactor vessel and steam generators. All of these primary system components have been removed leaving, as of September 2003, the concrete shield tank cavity structure surrounded by the steel sphere of the VC. The VC and support legs will be removed from site as radioactive waste leaving only the items listed above as an end state condition subject to these residual structures meeting the license termination criteria. i History: All the structures within BRT-01 have the same potential for being contaminated by work activities performed in the area. With the exception of the six leg RSS bases on the ring beam, the structures that comprise BRT-01 are of original plant construction. The six leg RSS bases on the ring beam received a seismic upgrade'modification in 1979.

Contamination: -

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area BRT-01 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete.

3. Continued In'vestigation: Continued investigation will evaluate below grade reinforced concrete.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been'performed on BRT-01.

Primary systems have been removed from the VC.

2. Planned: Planned decommissioning activities for the BRT-01 include the demolition of the BRT-01 related structures down to grade (elevation 1022'-8").

The VC and supporting legs will be removed.

3. Anticipated End State Configuration: The anticipate end state configuration consists of reinforced concrete support structures below 1022' -8".

7-15

YNPS Historical Site Assessment Revision 0 Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities planned, survey area BRT-01 is identified as a Class 1 Area.

North and South Decon Pads and Fuel Transfer Enclosure (NSY-01)

==

Description:==

NSY-01 consists of the following portions of the Service Building: the former north and south decontamination rooms and the recent addition to the structure south of the Hot Machine Shop (all of which are now referred to as the Fuel Transfer Enclosure, or FTE). The former north decon room consists of a reinforced concrete floor and concrete block walls. The former south decon room consists of a reinforced concrete floor surrounding a steel clad decontamination pad, with a drain trench around the perimeter. The walls of the former south decon room were removed and replaced with insulated metal panel and steel frame construction. The addition south of the former hot machine shop consists of the reinforced concrete floor and insulated metal panel and steel frame walls.

History: The FTE was used for closure of the NAC Nuclear Fuel Transportable Storage Canister in preparation for placement into the Vertical Concrete Casks (VCCs). Portions of the FTE were maintained as contaminated areas. Prior to construction of the FTE the north and south decon rooms were used to decontaminate and perform maintenance on plant components, tools and equipment. This area was also used for preparation of waste shipping containers/casks. The north and south decon rooms were generally maintained as a contaminated area.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-01 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in NSY-01

2. Planned: Planned decommissioning activities for the FTE include demolition the structure down to elevation 1022'-8" and decontamination or removal of the decon pads.

3. Anticipated End State Configuration: The end state configuration of the FTE is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area NSY-01 is identified as a Class I Area.

7-16

YNPS Historical Site Assessment Revision YNPS Historical Site Assessment Revision 00 Ion Exchange Pit (NSY-02)

==

Description:==

NSY-02 consists of the concrete structure that contained the purification system ion exchange vessels and filter capsules in a water- filled shield tank and an adjoining valve gallery and pipe chase that connected the Ion Exchange Pit (IX Pit) to the PAB. In addition, survey area NSY-02 includes the stairway leading to the foyer of the east PAB cubicle corridor access. The north wall of the IX Pit and the south wall of the spent fuel pool (SFP-01) are a common wall. The east wall of the IX Pit abuts NOL-02.

The south line of the IX Pit also abuts NOL-02. The west line of the IX Pit abuts AUX-01 andNOL-01.

History: Survey area NYS-02 (IX Pit) became contaminated as a result of purification system leakage into the shield water in the IX Pit and as a result of inadvertent misalignment of valves. The IX Pit itself leaked as a result of a flawed concrete joint in the northwest corner where it attaches to the SFP and the VC elevator foundation. This leak was repaired in 1965. It was also contaminated by spills during ion exchange resin transfers.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-02 are Co-60, Cs-137, Ag-108m, Sr-90, C-14, Fe-55, Am-241, Pu-238, 239/240,241 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil.

3. Continued Investigation: Reinforced concrete surface and subsurface structures, sub-surface soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NSY-02 include:

• Removal of the purification system valves, piping and pipe supports

• Concrete shield blocks

• Ion exchange vessels and filter capsules

• Decontamination via surface removal of the interior surfaces of the IX Pit and the valve gallery *  :

2. Planned: Planned decommissioning activities for the IX Pit included demolition the structure down to elevation 1022'-8" along the north and west walls, and to 1035 '-6" on the east and south walls;.An investigation of the impact of the IX Pit leakage during early plant operations on the adjacent open land survey areas (NOL,0I and NOL-02) with regard to the path of leakage into subsurface soils and into the groundwater will be conducted in accordance with section 2-5 (Continuing Investigati6n of Subsurface Contamination) and section 2-6 (Continuing Investigation of Groundwater Contamination) concurrent with the subsurface inVestigation 6f the Spent Fuel Pit (SFP-01).

3. Anticipated End State Configuration: The end state configuration of the IX Pit is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures 7-17

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this sirvey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-02 is identified as a Class 1 Area.

Safety Iniection and Diesel Generator Building (NSY-03)

==

Description:==

NSY-03 consists of the remainder of the Safety Injection/Diesel Generator Building (SI/DG) and includes the #3 Battery and MCC rooms. NSY-03 is bounded by NOL-06 on the north, south, and west and AUX-02 on the east. The original storm drain system and an electrical duct bank ran under the SI/Diesel building.

History: The SI/Diesel Building was constructed in 1970, adjacent to the northeast corner of the PAB. This location is suspected of having been contaminated prior to construction of the SI/Diesel Building. The SI/Diesel building contained radioactive systems that caused minor contamination of the floor area. The safety injection pumps leaked to a pump pedestal drain that was connected to a sump that was pumped to the gravity drain tank in the PAB. This drain system leak radioactive liquids into the surrounding soils under the SI/Diesel building floor.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-03 are Co-60, Cs- 137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete structures and subsurface structures, systems and soil Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NSY-03 include:

• Removal of the Safety injection system piping, valves, pumps and controls.

• Removal of the floor drain and surrounding soils

• Removal of the Diesel Generators and support systems.

• Removal of the #3 Battery and MCC.

• Removal of the electrical distribution systems in manhole #3.

• Removal of the walls and roof of the SI/Diesel building and the #3 Battery Room and MCC.

2. Planned: Planned decommissioning activities for NSY-03 included demolition the structure down to grade.

3. Anticipated End State Configuration: The end state configuration of NSY-03 is anticipated to include:

• Reinforced concrete structures (floor slabs)

• Subsurface concrete structures (foundations, electrical duct banks)

• Subsurface soil.

7-18

YNPS Historical Site Assessment Revision evison 0 Asessent Sie YNPSHistricl Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-03 is identified as a Class 1 Area.

Safe Shutdown System Building (NSY-04)

==

Description:==

NSY-04 consists of the Safe Shutdown System (SSS) Building. The SSS Building was constructed in 1985 in a portion of the RCA that had been temporarily cleared to facilitate its construction in a clean area. NSY-04 is bounded entirely by NOL-05.

History: Prior to 1985, the location of the SSS building was part of the RCA that was down grade from the radwaste storage area. The Safe Shutdown System Building became contaminated as a result of a radioactive liquid spill in 1985. The spill was cleaned-up and the building was subsequently maintained as a non-contaminated area.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-04 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NSY-04 include:

• Removal of the SSS diesel generator and support systems

• Removal ofthe SSS control panel and electrical distribution system.

• Removal of the SSS pumps, piping and tanks.

• Removal of a portion of the floor and contaminated soil under the floor.

2. Planned: Planned decommissioning activities for NSY-04 included demolition the structure.

3. Anticipated End State Configuration: The end state configuration of NSY-04 anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-04 is identified as a Class 1 Area.

Firewater Storage Tank and Diesel Fire Pump House (NSY-05)

==

Description:==

NSY-05 consists of the Firewater Storage Tank and Diesel Fire Pump House, constructed in 1979 in a portion of the RCA. NSY-05 is bounded entirely by NOL-04.

7-19

a-YNPS Historical Site Assessment Revision 0 History: Prior to 1979, the location of the Firewater Storage Tank and Diesel Fire Pump House were on the edge of the RCA, down slope from the Radwaste Storage Area. The Firewater Storage Tank and Diesel Fire Pump House have not been surveyed on a routine basis. The Firewater Storage Tank and Diesel Fire Pump House, although located in the RCA, are not considered radioactively contaminated structures.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-05 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil subsurface systems.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in NSY-05.

2. Planned: Planned decommissioning activities for NSY-05 include removal of the firewater storage tank, diesel driven pump and pump house.

3. Anticipated End State Configuration: The end state configuration of NSY-05 anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-05 is identified as a Class I Area.

New PCA Storage Building (NSY-06)

==

Description:==

NSY-06 consists of a pre- fabricated metal building that was constructed in 1975 in a portion of the RCA. NSY-06 is bounded by NOL,03 on the north, south, and east and bounded by NOL-04 on the west.

History: Prior to 1975, the location of the New PCA Storage Building was on the edge of the RCA and down slope from the radwaste storage area. NSY-06 was used as a radioactive material storage area and occasionally as a contaminated work area.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-06 are Co-60, Cs- 137, Ag- 108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil subsurface systems.

7-20

YNPS Historical Site Assessment YNPS Historical Site Assessment Revision 00 Revision Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in NSY-06.

2. Planned: Planned decommissioning activities for NSY-06 include removal of the metal structure.

3. Anticipated End State Configuration: The end state configuration of NSY-06 anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-06 is identified as a Class 1 Area.

Radioactive Waste Storage Tank Moat Area (NSY-07)

==

Description:==

NSY-07 consists of a concrete structure that provided a secondary containment function for radioactive liquids and provided shielding from radioactive liquids stored in the tanks. A drain valve isolated the moat area from the east storm drain system. NSY-07 is bounded by NOL-02 on the north, NOL03 on the east and south, and WST-03 on the west.

History: NSY-07 is part of the original plant structure. NSY-07 was contaminated by a pipe leak during early plant operations.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-07 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed: Decommissioning work activities performed under Decommissioning .

Work Packages (DWPs) include removal of tank 31 (Waste Hold-up Tank), tank-32 (Activity Dilution and Decay Tank).

2. Planned: Planned decommissioning activities for the NSY-07 includes demolition the structure down to grade.

3. Anticipated End State Configuration: The end state configuration of the NSY-07 is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-07 is identified as a Class 1 Area.

7-21

W-YNPS Historical Site Assessment Revision 0 New Safety Injection Tank Pad (NSY-08)

==

Description:==

NSY-08 consists of the New Safety Injection (SI) Tank Pad, constructed in 1991 in a portion of the RCA. NSY-08 is bounded entirely by NOL,05.

History: Prior to 1991, the location of the New SI Tank Pad was in the edge RCA and down slope from the Radwaste Storage Area. The new SI tank developed a leak from a temperature monitoring well located on the eastside of the tank. This leak resulted in miner contamination of the side of the tank and a portion of the tank pad.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-08 are Co-60, Cs-137, Ag- 108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil subsurface systems.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NSY-08 include:

a. Removal of the New SI Tank

b. Removal of the SI Tank piping.

2. Planned: Planned decommissioning activities will depend on the results of the continuing investigation.

3. Anticipated End State Configuration: The end state configuration of NSY-08 anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY-08 is identified as a Class 1 Area.

VC Elevator Foundation (NSY-09)

==

Description:==

NSY-09 consists of the foundation of the VC elevator structure.

History: NSY-09 is part of the original plant structure. The interior surface of NSY-09 was contaminated by the presence of loose contamination within the elevator shaft. The exterior of NSY-09 was likely contaminated by a leak from the Ion Exchange Pit (NSY-02).

Contamination:.

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-09 are Co-60, Cs-137, Ag- 108m, Sr-90 and H-3.

7-22

YNPS Historical Site Assessment Revision Revision 00 YNPS Historical Site Assessment

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in NSY-09.

2. Planned: Planned decommissioning activities for the NSY-09 includes demolition the structure down to elevation 1022'-8".

3. Anticipated End State Configuration: The end state configuration of the NSY-09 is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area NSY-09 is identified as a Class 1 Area.

ISFSI Pad (NSY-10)

==

Description:==

NSY- IOis the ISFSI Pad, constructed in 1999 on the former location of the Pole Barn. NSY- I0 is bounded entirely by NOL-07. The design and function of the VCC is such that no contamination of the ISFSI should result from their presence on the ISFSI.

History: Prior to 1999, this location was used for storage of materials and equipment some of which were radioactive materials. During construction of the ISFSI pad, a radiological assessment of some areas north of the pad (notably the NOL-03 and NOL-04 yard areas and the above grade exterior walls of structures within them) was performed using a technologically advanced method. The assessment was performed in anticipation that area background would be impacted by transfer of the fuel to the ISFSI pad. The ISFSI pad is now occupied by loaded VCC. The transportation of the loaded VCC was performed under strict controls to ensure that the transport process would not contaminate the ISFSI. The ISFSI is surveyed on a routine basis and it is anticipated to remain non-contaminated as a result of the presence of the VCC. Should future surveys identify the presence of contamination on the ISFSI pad then the survey area may be re-classified.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-I 0 are Co-60, Cs- 137, Sr-90.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil subsurface systems.

Deconmmissioning/Decontamination Activities

1. Performed: Decommissioning work performed under DWPs included removal of the Pole Barn and re-grading of the surface to facilitate ISFSI pad and road construction. Soils removed from the area were deposited primarily in Survey 7-23

_ __ U YNPS Historical Site Assessment Revision 0 Areas OOL-07 and OOL,09. Soils from the roadway approach area were deposited in Survey Areas OOL,02 and OOL10. .

2. Planned: Planned decommissioning activities will depend on the results of the investigation conducted when the ISFSI is taken out of service.

3. Anticipated End State Configuration: The end state configuration of NSY- 10 anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY- IO is identified as a Class 3 Area.

Chem-waste Transfer Pump Pit (NSY- I 1)

==

Description:==

NSY- 11 consists of a concrete vault, which houses the liquid waste transfer pumps that support the decon-room drains, the RP control point drains and the chemistry laboratory drains. NSY- I Iis bounded entirely by NOL-0 1.

History: NSY- II is part of the original plant structure. NSY- II was contaminated by leaks and/or spills that occurred during early plant operations.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY- II are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed- No decommissioning activities have been performed in NSY- 11

2. Planned: Decommissioning activities for the NSY- I Iwill depend upon the results of the continuing investigation.

3. Anticipated End State Configuration: The end state configuration of the NSY- 11 is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history, survey area NSY- 1Iis identified as a Class 1 Area.

7-24

YNPS Historical Site Assessment At Revision 0 Tank-i Base and Pipe Chase (NSY-12)

==

Description:==

NSY- 12 consists of the base for Tank- I (TK- 1)and a subsurface pipe chase that connects the TK- 1 base to the Auxiliary Boiler Room in the Turbine Building. NSY-12 is bounded entirely by NOL-06.

History: NSY- 12 is part of the original plant structure. There is no documentation indicating that NSY- 12 is contaminated; however, there is information that indicates that the area around NSY- 12 is potentially contaminated.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey areaNSY-12 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NSY- 12 include removal of TK-1 and related systems.

2. Planned: Decommissioning activities for the NSY-12 will depend upon the results of the continuing investigation.

3. Anticipated End State Configuration: The end state configuration of the NSY-12 is anticipated to include:

• Reinforced concrete'structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY- 12 is identified as a Class I Area.

Tank-39 Base Demineralized Water Storage Tarik (NSY-13)

==

Description:==

NSY- 13 consists of the base for Tank-39 (TK-39). NSY- 13 is bounded entirely by NOL-02.

History: NSY- 13 'is part of the original plant structure. There is a history of tritium being detected in the tank water but no other radionuclides. The tank has recently been'drained.

There is information that indicating that the area around NSY- 13 (tank base) is potentially 'contaminated.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NSY-12 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2.' Media: Reinforced concrete, surface soil, sub-surface soil

3. Continued Investigation: Reinforced concrete, surface soil, sub-surface soil 7-25

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 Decommissioning/Decontamination Activities

1. Performned: No Decommissioning activities have been performed in NSY- 13.

2. Planned: Decommissioning activities planned for NSY- 13 will include the removal of Tank-39. Disposition of the concrete tank base will depend upon the results of the continuing investigation.

3. Anticipated End State Configuration: The end state configuration of the NSY-13 is anticipated to include:

• Reinforced concrete structures

• Subsurface concrete structures

• Subsurface soil.

Classification Statement: Based upon the radiological condition of this survey area identified in the operating history and as a result of the decommissioning activities performed to date, survey area NSY- 13 is identified as a Class I Area.

7.3.2.1.3 Open Land Areas Eastern Lower RCA Yard (NOL-01)

==

Description:==

NOL-01 is the land area within the RCA that is bounded by NOL-06, FTE and Service Building on the north; the east boundary of the RCA (OOL- 12) to the east; NOL-02, the New Fuel Vault/Spent Fuel Pit and PAB on the south; and the NOL-06 on the west. The bounds of NOL-01 were established such that it is appropriately sized as a Class I survey unit according to MARSSIM. Subsurface structures within NOL-01 will be surveyed as a survey unit within the survey area.

History: In addition to the normal migration of minor levels contamination in the RCA NOL-01 was contaminated by the following events:

• Overfilling of the Spent Fuel Pool.

• Leaks associated with fuel transfer chute pump.

• A Reactor Head removal contamination event.

• Leakage from the IX Pit during early plant operations Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NOL-01 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil from known spill events as described in sections 2.2.3 and 2.2.4.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NOL-01 include the construction of the landing pads for reactor vessel removal and fuel transfer casks., construction of the Spent Fuel Pit Security Blast Shield Wall (this entailed 7-26

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision some remediation of contaminated soils disposed of as radioactive waste), and installation of Auxiliary Service Water System..

2. Planned: Future decommissioning activities are dependent uon the results of continued investigations.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey are sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history and as a result of the decommissioning'activities performed to date, survey area NOL-01 is identified as a Class 1 Area.

Northeast Upper RCA Yard (NOL,02)

==

Description:==

NOL-02 is' the land area within the RCA that is bounded by the Exchange Pit/New Fuel Vault and NOLl0 on the north, the east boundary of the RCA (OOL 11) to the east, NOL-03 and the Liquid Waste Storage Tanks (NSY-07) on the south and the NOL-05 and Waste Disposal on'the west. The bounds of NOL-02 were established such that it is appropriately sized as a Class 1 survey unit according to MARS SIM. Subsurface structures identified within NOL-02 will be surveyed as a survey unit within the survey area.

History: In addition to the normal migration of minor levels contamination in the RCA NOL,02 was contaminated or affected by the following events:

• A resin spill during resin transfer operation

• The inadvertent severing of a buried radwaste transfer piping

• Leak from piping associated with Test Tanks

• Release of Test Tank liquids during sample collection

• A subsurface break in the fire protection piping.

• Leakage from the IX Pit during early plant operations Contamination:

1. Radionuclides Potentially Present: -The primary radionuclides of concern for survey area NOL-02 are Co-60, Cs-137, Ag-108m, Sr-90 and H1-3.

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil from known spill events as described in sections 2.2.3 and 2.2.4.,

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NOL,02 include:

• Removal of the Test Tanks

• Removal of the Monitor Tanks

• Removal of waste transfer piping.

• Removal of contaminated soils identified in area of the test tanks.

7-27

- ~ -a YNPS Historical Site Assessment Revision 0

• Backfill of excavations with surveyed clean soil.

2. Planned: Future decommissioning activities are dependent upon the results of continued investigations.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area NOL-02 is identified as a Class I Area.

Southeast Upper RCA Yard (NOL.03)

==

Description:==

NOL-03 is the land area within the RCA that is bounded by the NOL,02 and the Liquid Waste Storage Tanks (NSY-07) on the north, the east boundary of the RCA (OOL- I1) to the east, OOL- 10 on the south and the NOL-04 and the radwaste warehouse complex on the west. The bounds of NOL-03 were established such that it is appropriately sized as a Class I survey unit according to MARSSIM. Subsurface structures and system identified within NOL-03 will be surveyed as a survey unit within the survey area.

History: In addition to the normal migration of minor levels contamination in the RCA NOL-03 was contaminated by the following event:

• Radioactive Material storage.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NOL,03 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NOL-03 have removed contaminated soils identified in area of radioactive material storage. Excavations were backfilled with surveyed clean soil.

2. Planned: Future decommissioning activities are dependent upon the results of continued investigations.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area NOL-03 is identified as a Class I Area.

7-28

YNPS Historical Site Assessment Revision Revision 00 YNPS Historical Site Assessment Southwest Upper RCA Yard (NOLU04)

==

Description:==

NOL04 is the land area within the RCA that is bounded by the NOL-05 and the radwaste warehouse on the north, NOL-03 and NSY-06 on the east, OOL- 10 on the south and west. NOL-04 is appropriately sized as a Class 1 survey unit according to MARSSIM. Subsurface structures and system identified within NOL-04 will be surveyed as a survey unit within the survey area.

History: In addition to the normal migration of minor levels contamination in the RCA NOL-04 was contaminated by temporary storage of packaged radioactive material awaiting shipment.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NOL-04 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in NOL-04

2. Planned: Future decommissioning activities are dependent upon the results of continued investigations.

3. Anticipated End State Configuration:'A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area NOL,04 is identified as a Class 1 Area.

Northwest Upper RCA Yard (NOL05)

==

Description:==

NOL.05 is the land area within the RCA that is bounded by the NOL-06 and the PAB on the north, NOL02 and the waste disposal and radwaste warehouse on the east, NOL-04 on the south and OOL-l0 on'the west. NOL-05 is appropriately sized as a Class 1 survey unit according to MARSSIM. Subsurface structures and systems identified within NOL-05 will be surveyed as a separate 'survey unit within the survey area.

History: In addition to the normal migration of minor levels contamination in the RCA NOL-05 was contaminated by radioactive liquid leakage from the original plant Safety Injection Tank.

Contamination:

1. Radionuclides Potentially Present: The prima*y radionuclides of concern for survey area NOL-05 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

7-29

YNPS Historical Site Assessment Revision 0

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NOL-05 include:

• Removal buried piping connecting the Safe Shutdown System Building to the PAB

• Removal of both the original and new Safety Injection Tanks

• Removal of the piping connecting the Safety Injection Tanks to the PAB.

2. Planned: Future decommissioning activities are dependent upon the results of continued investigations.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area NOL,05 is identified as a Class 1 Area.

Western Lower RCA Yard (NOL-06)

==

Description:==

NOL.06 is the land area within the RCA that is bounded by the OOL-IO and the Turbine Building on the north; the FTE, NOLOlI and the PAB on the east; NOL,05 on the south; and OOLl10 on the west. The bounds of NOL-06 were established such that it is appropriately sized as a Class 1 survey unit according to MARSSIM. Subsurface structures and system identified within NOL-06 will be surveyed as a survey unit within the survey area.

History: NOL-06 was contaminated by the normal migration of minor levels contamination in the RCA.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NOL.06 are Co-60, Cs-137, Ag-108m, Sr-90 and 113.

2. Media: Surface and subsurface soil and sub-surface concrete.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures, systems and the extent of contamination in soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in NOL-06 include:

• Remediation of mixed waste along the south wall of the SI/Diesel Building.

• Construction of the Fuel Transfer Haul road under the VC.

2. Planned: Future decommissioning activities are dependent upon the results of continued investigations.

7-30

YNPS Historical Site Assessment Revision 0

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area NOL-06 is identified as a Class 1 Area.

ISFSI RCA Yard (NOL-07)

==

Description:==

NOL07 is the land area that bounds the ISFSI pad and bounded entirely by OOL11O History: NOL,07 was constructed at the same time as theISFSI. A comprehensive radiological assessment of this area was performed prior to construction of the ISFSI.

Previously this area was used as a material storage area. Some of this material was later identified as radioactive material. A survey of this area under the guidelines of NUREG/CR-5849 was conducted prior to grading.' Samples have been taken of each load of soils removed from the area. These sarmples showed no detectable activity. All soils removed from the area were deposited in survey areas OOL-07 (Class 2) and OOL-09 (Class 3).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area NOL-07 are Co-60, Cs-137, and Sr-90.

2. Media: Surface and subsurface soil.

3. Continued Investigation: Continued investigation will not be performed until the spent fuel and waste stored on. the ISFSI has been removed.

Decommissioning/Decontamination Activities'

1. 'Performed:'Disniantlemient of a pole barn structure and noi-rad material storage area. The area was then graded in preparation for construction of the ISFSI pad.

New concrete was used in the structure. Fuel Storage Casks have been placed on the pad and are in their final configuration.

2. Planned: Future decommissioning activities are'dependent'upon the results of continued investigations

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey will be sufficiently exposed to allow survey.'

Classification Statement: Based upon the current/best information indicating the radiologicallconditions and on conditions and events identified in the 6perating history, survey area NOL-07 is identified as a Class 3 Area. It is not expected that any radioactive material will leave the confines of the fuel casks and residual contamination after '

removal of the fuel casks is anticipated to be less than a small fraction of the DCGLs.

'7-31

-I -

YNPS Historical Site Assessment Revision 0 7.3.2.2 Buildings, Structures and Open Land Areas Outside the RCA The following designations are used in identifying survey areas outside of the RCA (Figures 7-3 and 7-4):

OMB Support Buildings Outside the RCA OOL Open Land Areas Outside the RCA SVC Service Building TBN Turbine Building Summary individual Survey Area assessments are described in Appendix 7B. In general, the impacted areas immediately outside the confines of the historical RCA have been assigned a Class 2 status. These buffer zones are areas where radionuclides may have migrated beyond the RCA boundary due to environmental or other translocation vectors.

The exceptions are Survey Areas OOL, 12 and OOL, 13 where radionuclides are known to have migrated beyond the RCA boundary due to the combination of a recorded contaminating event (PIR 81-09) and a significant rain event. Surface run-off from the RCA yard not channeled into the storm drain system migrated down grade along the rail spur in these areas toward Sherman Reservoir. Although the surfaces of these areas were quickly decontaminated and cleared for general access, some of the contamination carried by the run-off filtered into the crevices of the rails and rail bed remain embedded. These areas have been assigned a Class 1 status.

Survey Area OOL,07 has been assigned a Class 2 status as it contains soils removed from other Class 2 areas and soils that have only been evaluated by composite sampling techniques.

The remaining impacted areas are assigned a Class 3 status. These areas were designated as impacted areas for a wide variety of reasons. None of these areas are expected to contain radioactivity in excess of a small fraction of the appropriate DCGL.

7.3.2.2.1 Buildings and Structures Screen-well Pump House (OMB-01)

==

Description:==

OMB-01 is a YNPS structure located on U S Gen owned property. OMB-0I is located within the bounds of survey area OOL,03, a Class 3 land survey area. OMB-01 consists of reinforced concrete that forms the intake and screen-well structure below grade and steel frame and block structure that housed the pump motors and controls above grade. The intake structure connects to Sherman Reservoir through a corrugated metal pipe. The pump discharge connects to the turbine building through 84 inch diameter concrete pipe.

7-32

Revision YNPS Historical Site Assessment YNPS Historical Site Assessment Revision 00 History: The systems present and the processes performed in OMB-01 did not involve radioactive materials. There is no information that identifies the presence of radioactive materials in OMB-01. Access to OMB-01 is through OOL-03 a Class 3 land survey area, there is a potential that contamination may have been translocated to OMB-01 from OOL-03.

Draft NUREG/CR-5849 based surveys performed 9/2/98 identified no licensed radioactivity present.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-01 are Co-60, Cs-137, Sr-90 and H-3 resulting from the intake of waters and sediments at Sherman Reservoir. Sherman Reservoir receives the discharge of the circulating water system, which includes permit released liquid radioactive effluents. The East Storm Drain System also discharges to Sherman pond, which is known to contain radioactivity from surface run-off from within the RCA.

2. Media: Reinforced concrete, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils. Potential for migration of radioactivity exists from groundwater movement along the backfill around the circulating water system piping located below the Turbine Building. This will be investigated by core bore sampling of soils adjacent to and under the circulating water system piping under the Turbine Building.

Decommissioning/Decontamination Activities

2. Performed: Decommissioning activities performed in OMB-01 include:

• Removal of the circulating water pump motors and impellers.

• Removal of the circulating water pipes within the structure.

• Removal of the traveling screen equipment in the Intake Structure

• Removal of the service water pumps and pipes within the structure.

• Installation of the Auxiliary Service Water System (ASWS)

3. Planned: No further decommissioning activities are planned at this time.

4. Anticipated End State Configuration: OMB-01, if present, will be surveyed as it currently exists: Reinforced concrete, concrete blocks, and structural steel. This' structure may be removed in its entirety, subject to FERC approval.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the HSA, survey area OMB-01 is identified as a Class 3 Area.

Security Gatehouse and Diesel Generator Building (OMB-02)

==

Description:==

OMB-02 is located on YAEC owned property. OMB-02 is bounded by OOL-02 on the north, east, south and OOL,06 on the west. OMB-02 consists of

_. 7-33

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision reinforced concrete and block structures. OMB-02 functions as the access control point for the YNPS site. It also now houses the YNPS control room. Survey area OMB-02 also includes the Security Diesel Generator Building that supplies emergency power to the Gatehouse and the ISFSI. A portion of the West Storm Drain System runs under OMB-

02. The potable water and sanitary sewer systems connect to OMB-02.

History: The use of radioactive materials in OMB-02 involved electro-plated or sealed check sources for instrument response verification. There is information that identifies events involving radioactive material present in OMB-02 resulting from infrequent and unintentional translocation of plant related radioactivity into OMB-02 from within the RCA. Contamination monitors were operated at the gatehouse as a final check for radioactivity on personnel leaving the industrial area. When contamination was identified at the OMB-02 monitors it was cleaned-up and a post decontamination survey performed to verify no detectable residual contamination. It is anticipated that any residual contamination, if present in OMB-02, would not exceed a small fraction of the appropriate DCGLs.

Contamination I. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-02 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Reinforced concrete, concrete block, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performned in OMB-02 include the relocation of the Control Room into the gatehouse.

2. Planned: No further decommissioning activities are needed at this time.

3. Anticipated End State Configuration: OMB-02 will be surveyed as it currently exists, a reinforced concrete and concrete block structure.

Classification Statement: Based upon the currentlbest information indicating the radiological conditions and on conditions and events identified in the HSA, survey area OMB-02 is identified as a Class 3 Area.

Administration Building (OMB-03)

==

Description:==

OMB-03 is located on YAEC owned property. OMB-03 is bounded entirely by OOL,06. OMB-03 consists of a metal frame and panel structure set on a reinforced concrete pad. OMB-03 functions as the Administration Office Building.

History: The systems present and the processes performed in OMB-03 did not involve use of radioactive materials. Over its history as a visitor center and training center, various radioactive materials were present in the building including electro-plated and sealed check sources and examples of naturally occurring radioactive materiab and consumer products.

7-34

YNPS Historical Site Assessment Revision 0 Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-03 are Co-60 and Cs-137.

2. Media: Reinforced concrete, surface soil.

3. Continued Investigation: Continued investigation will evaluate the structure as it currently exists.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in OMB-03.

2. Planned: No further decommissioning activities are needed at this time.

3. Anticipated End State Configuration: OMB-03 will be surveyed as is; Reinforced concrete, structural steel and generic building materials.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OMB-03 is identified as a Class 3 Area.

Warehouse and Loading Dock (OMB-04)

==

Description:==

OMB-04 is located on YAEC-owned property. OMB-04 is bounded by OOL-02 on the north and east, OOL-12 on the south and SVC-03 on the west. OMB-04 consists of a metal frame and panel structure set on a concrete pad.

History: Although a single structure now, OMB-04 previously consisted of two structures: the original warehouse and a separate two bay garage. The warehouse and garage were connected by construction of an addition that spanned the gap between the east end of the warehouse and the west end of the garage. The construction of the Service Building Annex connected to the warehouse to the Service Building. A two-inch thick layer of concrete was poured over the existing floor of the warehouse as part of a loading dock modification.

OMB-04 was used as a storage location for plant equipment and materials and was not intended for storage of radioactive materials. There were incidents where radioactively contaminated equipment was inadvertently stored in OMB-04. The contamination consisted of loose radioactive material, resulting from the unintentional translocation of contaminated equipment into OMB-04 from the RCA. When these events were identified the radioactive contamination was cleaned-up with the results of decontamination verified through survey. It is anticipated that any residual contamination, if present in OMB-04, would not exceed a small fraction of the appropriate DCGLs.

Survey area OMB-04 is adjacent to a Class 1 open land area (QOL- 12). The mode of contamination of OOL-12 was via surface water run-off from the inside the RCA. The entire surface of survey area OMB-04 is elevated above the prevailing grade of the surface water run-off pathway in survey area OOL-12. Consequently survey area OMB-04 was not impacted by this mode of contamination spread. Residual contamination in 7-35

_ _ _ _ _---U YNPS Historical Site Assessment Revision 0 survey area OOL- 12 is embedded into crevices of the rail bed and is not available fr translocation by foot traffic.

Contamination I. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-04 are Co-60, Cs-137, Ag-108m, Sr-90 and H-3.

2. Media: Concrete.

3. Continued Investigation: Continued investigation will evaluate the structure as is and the backfill surrounding the recently installed ASWS.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OMB-04 included:

• Installation of the Auxiliary Service Water System.

• The steel frame and panel structure has been demolished and removed from site.

2. Planned: none

3. Anticipated End State Configuration: Concrete floor slab and reinforced concrete loading dock structure.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OMB-04 is identified as a Class 3 Area.

Furlon House (OMB-05)

==

Description:==

OMB-05 is located on YAEC owned property. OMB-05 is bounded entirely by OOL- 16. OMB-05 is a wood frame structure set on a stone and concrete foundation and was constructed prior to construction and operation of YNPS.

History: OMB-05 was used for storage of emergency response equipment some of which was radioactive material (respirators, protective clothing, etc) also radioactive material in the form of electro-plated and sealed check sources used to verify instrument operability.

The emergency response equipment as radioactive material was packaged and the package surveyed prior to placement into storage in OMB-05.

After 9/1 1/01 OMB-05 was designated as the shipping and receiving location for the YNPS site. Radioactive material packages to be shipped are brought to OMB-05 in a condition ready for shipment, no preparation of packaged radioactive material is performed in OMB-05. No radioactive material packages are opened in OMB-05.

Radioactive material packages received at the YNPS site are surveyed in accordance with transportation regulations to verify radioactive material package integrity prior to opening. Packages are opened inside the RCA.

Draft NUREG/CR-5849 based surveys performed in 1998 identified no licensed radioactivity detectable. Only naturally occurring radionuclides were identified during 7-36

YNPS Historical Site Assessment Revision Revision 00 YNPS Historical Site Assessment the scans of the lower walls and floors and total surface contamination measurements.

No exposure rate or loose surface contamination measurements were obtained.

In August of 2003 the foundation was repaired on the south wall. Soils excavated from the work area were deposited in OOL-07.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-05 are Co-60 and Cs-137. This radioactivity would have been reintroduced to the area after 1998 and, if present, would be a small fraction of the DCGL.

2. Media: Generic Building Materials.

3. Continued Investigation: Continued investigation will evaluate the structure as is.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in OMB-05.

2. Planned: No further decommissioning activities are planned.

3. Anticipated End State Configuration: The structure will remain as is.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OMB-05 is identified as a Class 3 Area.

Seal Pit (OMB-06)

==

Description:==

OMB-06 is a YNPS structure located on U S Gen owned property. OMB-06 is bounded by survey area OOL-03 on the east south and west and by survey area 001, 01 on the north. OMB-01 consists of reinforced concrete that forms the discharge structure of the circulating water system. The discharge structure is located at the edge of Sherman Reservoir and is the terminus of the 84 inch diameter concrete pipe returning circulating system water to Sherman Reservoir.

History: The circulating water system is the ultimate discharge point for 10 CFR 20 permitted releases of liquid radioactive effluents. Access to OMB-06 is through OOL-03 a Class 3 land survey area; there is a potential that contamination may have been translocated to OMB-06 from 00L-03.

Draft NUREG/CR-5849 based surveys performed in 1998 identified licensed radioactivity present in scale built up onthe circulating water pipes upstream from OMB-06 and in pond sediment samples collected in the bay of Sherman Reservoir (OOL-01) in front of OMB-06. The radioactive material concentrations detected in the pond sediment as well as sediments taken from inside the structure after the circulating water system was deactivated, is below the proposed DCGLs for soil. The circulating water piping will be surveyed as part of the continuing characterization investigations and will either be free released or will be removed and disposed of as low-level radioactive waste. The, accumulation of sediments within structure will be removed. It is expected that any residual contamination, if present in OMB-06, would not exceed a small fraction of the appropriate DCGLs.

7-37

-_ _ a-YNPS Historical Site Assessment Revision 0 Contamination I. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OMB-06 are Co-60, Cs-137, Sr-90 and H-3 resulting from the permitted release of liquid radioactive effluents into the circulating water system, discharge to Sherman Reservoir.

2. Media: Reinforced concrete, accumulated sediment within the structure.

3. Continued Investigation: Continued investigation will evaluate reinforced concrete and sediments. Potential for migration of radioactivity exists from groundwater movement through the backfill around the outside of the circulating water system piping located below the Turbine Building. This will be investigated by core bore sampling of soils adjacent to and under the circulating water system piping under the Turbine Building.

Decommissioning/Decontamination Activities

1. Performed: None

2. Planned: No decommissioning activities are planned at this time.

3. Anticipated End State Configuration: OMB-06 will be surveyed as is: Reinforced concrete.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the HSA, survey area OMB-06 is identified as a Class 3 Area.

Turbine Building and Portions ofService Building Outside of tihe RCA Turbine Building and Offices (TBN-01)

==

Description:==

TBN-01 is bounded by 00L-02 on the north, SVC-01 on the east, NOL,06 on the south and OOL,10 and OOL,02 the west. The TBN-01 consists of a steel frame and concrete block lower structure with a steel frame and metal panel upper structure.

History: The systems present and the processes performed in TBN-01 were not intended to involve the radioactive materials. There is information that identifies conditions and events where radioactive material was present in the TBN-01.

A portion of the Turbine Building became contaminated in 1967 while a main coolant pump was being refurbished on the turbine deck, at that time the area was decontaminated. The event was incorporated into plans for decommissioning activities and survey plans developed for this area.

The condensate system contained radioactive materials as a result of primary to secondary system leakage that occurred in the steam generators. Contamination from this condition was identified in the condensate piping and components, in the floor drain system and in the soil around and under the floor drains. Additional contaminated concrete surfaces and soil below the concrete floor were identified near turbine support 7-38

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision pedestal #4. All of these identified subsurface locations have undergone a successful mitigation process and have been backfilled to grade. The interior of the structure and slab were surveyed under NUREG/CR-5849 criteria after phase I decommissioning activities were complete.

The general sub-surface conditions are the subject of continuing investigation.

Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area TBN-OI are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Reinforced concrete, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below-grade reinforced concrete and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in TBN-Ol include:

• Removal of secondary systems.

• Removal of equipment.

• Removal of sub-floor systems (floor and equipment drains, service water piping).

• Removal of soil from around the sub-floor systems.

• Soil excavations backfilled.

2. Planned: Planned decommissioning activities for the TBN-O1 include demolition of the entire structure to grade.

3. Anticipated End State Configuration: Reinforced concrete structure (floor slab),

sub-floor soils, sub-grade structures.

Classification Statement: Based upon the current/best information indicating the radiobgical conditions and on conditions and events identified in the operating history, survey area TBN-01 is identified as a Class 3 Area.

Non-Rad Service Building (SVC-01)

==

Description:==

SVC-01 is bounded by OOL-02 on the north, by SVC-03 on the east, by SVC-02 on the south and TBN-Olon the west. The SVC-01 consists of a steel frame and concrete block structure built on reinforced concrete floor slab and foundations.

History: The systems present and the processes performed in SVC-01 did not involve the use of radioactive materials other than radioactive electroplated and sealed check sources used to test instrumentation operability. SVC-01 is adjacent to the radiation protection (RP) control point and was maintained as a clean area. There is information concerning events involving radioactive material contamination identified present in SVC-01. The contamination consisted of loose contamination, resulting from inadvertent translocation of radioactivity into SVC-Olfrom the RCA at the control point. When these events were identified the radioactive contamination was cleaned- up and the area surveyed. It is anticipated that any residual contamination, if present in SVC-01, would not exceed a small fraction of the appropriate DCGLs.

7-39 -

YNPS Historical Site Assessment Revision 0 Contamination

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area SVC-01 are Co-60, Cs- 137, Ag- 108m, Sr-90 and H-3.

2. Media: Reinforced concrete, sub-surface soil

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete structures and adjacent sub-surface soils Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in SVC-0 I include:

• Removal of secondary systems.

• Removal of equipment.

2. Planned: Planned decommissioning activities for the SVC-01 include demolition of entire structure to elevation 1022'-8".

3. Anticipated End State Configuration: Reinforced concrete structure (floor slab).

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area SVC-01 is identified as a Class 3 Area.

Service Building Addition (SVC-03)

==

Description:==

SVC-03 is bounded by OOL-02 on the north, OOL-02 and OMB-04 on the east, SVC-02 on the south, and SVC-02 and SVC-Olon the west. SVC-03 consists of a steel frame and concrete block structure. The ground floor corridor that runs north and south located in the southwest corner of the Service Building Addition and the south most room adjacent to it, are not included in SVC-03 but are included in SVC-02.

History: The systems present and the processes performed in SVC-03 did not involve use of radioactive materials. There is information that identifies inadvertent transmigration of plant-related radioactivity into SVC-03. The contamination consisted of loose radioactive material, resulting from inadvertent translocation of radioactivity into SVC-03 from the RCA. When these events were identified the radioactive contamination was cleaned-up with the results of decontamination verified through survey. It is anticipated that any residual contamination, if present in SVC-03, would not exceed a small fraction of the appropriate DCGLs.

A portion of the SVC-03 was built on top of what was a portion of the RCA from the time prior to its construction. This circumstance will be investigated as part of the continuing investigation of subsurface locations; however, it is anticipated that any residual contamination, if present beneath the poured slab, would not exceed a small fraction of the appropriate DCGLs.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area SVC-03 are Co-60, Cs- 137, Ag- 108m, Sr-90 and H-3.

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YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0

2. Media: Reinforced concrete, surface soil, subsurface soil.

3. Continued Investigation: Continued investigation will evaluate below grade reinforced concrete and adjacent sub-surface soils.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in SVC-03 include:

• Removal of secondary systems.

• Removal of equipment.

• Demolition and removal of the non-RCA portion of the structure.

2. Planned: Planned decommissioning activities for the SVC-03 include demolition of walls to grade.

3. Anticipated End State Configuration: The end state configuration of WST-04 is anticipated to include:

• Surface concrete structures (floor slab)

• Subsurface concrete structures (foundations)

• Subsurface soil.

Classification Statement: Based upon the current/best information indicating the radiological conditions and upon conditions and events identified in the operating history and activities performed during decommissioning, survey area SVC-03 is identified as a Class 3 Area.

7.3.2.2.2 Open LandAreas Outside of the RCA (OOL)

Sherman Pond Sediment (OOL-41)

==

Description:==

OOL-01 consists of the sediment layers in Sherman Pond and is bounded by the continuation of Sherman Pond on the north, OOL- 15 on the east, OOL- 13 and OOL-03 on the south and OOL.03 on the west. Sherman Pond is owned by US Gen.'

History: OOL-01 has received surface rur-off from the east end of the RCA via OOL-12 ahd OOL-13 and also discharge of the east storm drain system. It also received the permitted liquid waste discharge effluent that was released from the site via the circulating water system. A significant amount of sediment sampling was performed over the life of the plant under the Radiological Environmental Monitoring Program (REMP) with no impact being noted. Additional sediment sampling has been performed in OOL-0I following the cessation of power operations. Scoping samples of pond sediment indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).'

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-0I are, Cs-137, Sr-90 and H-3. PCBs'have also been identified in the sediments of Sherman Pond.

2. Media: Sediment 7-41

YNPS Historical Site Assessment Revision 0

3. Continued Investigation: Continued investigation will be necessary to support possible PCB sediment removal.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in OOL-01

2. Planned: Future decommissioning activities may include sediment removal for non-radioactive concerns.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the currentlbest information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-0I is identified as a Class 3 Area.

Yankee Non-Rad Yard Area (OOL-02)

==

Description:==

OOL-02 consists of the land area (owned by YAEC), in the yard area within the current industrial area of the YNPS site. Survey Area OOL-02 is bounded by the YAEC/US Gen property line on the north; OOL-12 and OOL-13 on the east, the Warehouse/Service Building/Turbine Building complex, plus the OOL- 10 and OOL-08 on the south and OOL-06 on the west. Subsurface systems present in OOL-02 include the east storm drain system, security lighting and video conduit runs, sanitary sewer system, fire protection water system and the circulating water system.

History: The west end of Survey Area OOL-02 received surface run-off from OOL- 10, a Class 2 survey area. On the east end OOL-02 is located upslope from survey areas OOL-12 and OOL- 13 and so was not subject to run-off from out of the RCA. OOL-02 has been the main travel path for all material, including radioactive material received at or shipped from the YNPS site. Scoping samples of various survey media in OOL-02 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-02 are Co-60, Cs- 137, Sr-90 and H-3.

2. Media: Surface and subsurface soil.

3. Continued Investigation: Continued investigation will be necessary to assess subsurface structures and systems.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OOL-02 include:

• Removal of subsurface system components that traverse OOL-02

• Installation of the Auxiliary Service Water system.

2. Planned: Future-decommissioning activities may include removal of certain subsurface structures and systems.

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YNPS Historical Site Assessment Revision YNPS Historical Site Assessment Revision 00

3. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey are sufficiently exposed to allow survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history and as a result of the decommissioning activities performed to date, survey area OOL-02 is identified as a Class 3 Area.

Sherman Reservoir Dam and South Shoreline (OOL-03)

==

Description:==

OOL-03 consists of the land area owned by US Gen. Survey Area OOL-03 is bounded by the Deerfield River and Sherman Reservoir on the north, OOL- 13 on the east, the YAEC, US Gen property line (OOL-02) on the south and OOL-04 on the west.

Subsurface systems present in OOL-02 include the east storm drain system, security lighting and video conduit runs, sanitary sewer system fire protection water system and the circulating water system.

History: Survey Area OOL-03 has received surface run-off from OOL-02 a Class 3 survey area. OOL-03 has been used as a path of travel for radioactive material received at and shipped from the YNPS site. The HSA has identified that there are, nocontaminating events associated with OOL-03. Scoping samples of various survey media in OOL-03 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-03 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface and subsurface soil.

3. Continued Investigation:.Continued investigation will be necessary to assess subsurface structures and systems.

Decommissioning/Decontamination Activities

4. Performed: No decommissioning activities" have been performed in survey area OOL-03.

5. Planned: Future-decommissioning activities may include removal of certain subsurface structures and systems

6. Anticipated End State Configuration: A soil surface configuration suitable for survey. Subsurface structures requiring survey are sufficiently exposed to allow survey.

Classification-Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-03 is identified as a Class 3 Area.

7-43

- a-YNPS Historical Site Assessment Revision 0 US Gen Sherman Station (OOL-04)

==

Description:==

OOL-04 consists of the land area owned by US Gen. Survey Area OOL-04 is bounded by the Deerfield River on the north, OOL,03 on the east, the YAEC/US Gen property line (OOL-02) on the south and OOL-05 on the west.

History: Survey Area OOL-04 has received surface run-off from the OOL-02 a Class 3 survey area. The groundwater within Survey Area OOL-04 is suspected of containing radioactivity originating from the operations at YNPS. Sherman Spring, located in Survey Area OOL-04, has been determined to contain plant related radioactivity (tritium). Scoping samples of various survey media in OOL-04 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-04 are Co-60, Cs-137, Ag-108m, Sr-90 and 11-3.

2. Media: Surface and subsurface soil, surface water and groundwater.

3. Continued Investigation: Continued investigation will be necessary to assess subsurface soil, surface water and groundwater.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-04.

2. Planned: Future-decommissioning activities may include removal of certain soils depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey and access to surface water and groundwater.

Classification Statement: Based upon the currentibest information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-04 is identified as a Class 3 Area.

US Gen Deerfield River Frontage Property (OOL-05)

==

Description:==

OOL-05 consists of the land area owned by US Gen. Survey Area OOL-05 is bounded by the Deerfield River on the north, OOL-04 on the east, the YAEC, US Gen property line (OOL-06) on the south, and by non-impacted US Gen owned property on the west.

History: Surxey Area OOL-05 has received surface run-off from OOL-06 and the west storm drain system of YNPS. The septic waste disposal systems associated with YNPS are located within the bounds of OOL-05. The original septic system leach field was abandoned in place after it became clogged with solids. A radiological assessment of the leach field identified the presence of low levels of Co-60. Scoping samples of various survey media in OOL-06 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

7-44

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-05 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface and subsurface soil, surface water and groundwater.

3. Continued Investigation: Continued investigation will be necessary to assess surface and subsurface soil, surface water and groundwater.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-05.

2. Planned: Future-decommissioning activities may include removal of certain soils depending upon the results of-the continuing investigation and actions required to discontinue use of or close the leach fields.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey and access to surface water and groundwater.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-05 is identified as a Class 3 Area.

YNPS Western Access (OOL-06)

==

Description:==

OOL-06 consists of the land area owned by YAEC and is bounded by the YAEC/US Gen property line (OOL-05) on the north, OOL-02 and OOL-08 on the east, OOL-08 on the south and non-impacted YAEC owned property on the west. OOL-06 contains within its bounds survey areas OOL-07 and OMB-03. Subsurface systems present in OOL-06 include the west storm drain system, the site electrical supply conduits and the sanitary sewer system associated with OMB-03. Adjacent to OOL-07 is the location of the YNPS trash compactor and salt/sand shed, both of which are temporary structures. The surface area of OOL-06 is indigenous soils and asphalt of the parking lots area and roadways. There are numerous temporary structures present in OOL-06.

History: Survey Area OOL-06 has received surface run-off from the OOL02 and is the outfall of the west storm drain system. OOL-06 contains the primary access point for the YNPS site and is a travel path for material, including radioactive material received at or shipped from the YNPS site. There is an abandoned leach field as well as an active leach field both associated with the administration building located within the bounds of OOL-

06. Scoping samples of various survey media in OOL-06 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-06 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface and subsurface soil, surface water and groundwater.

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YNPS Historical Site Assessment Revision 0

3. Continued Investigation: Continued investigation will be necessary to assess surface and subsurface soil, surface water and groundwater.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL,06.

2. Planned: Future decommissioning activities may include removal of certain soils depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey and access to surface water and groundwater.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL,06 is identified as a Class 3 Area.

Spoils Deposit Area (OOL,07)

==

Description:==

OOL,07 consists of the land area owned by YAEC. OOL,07 is bounded entirely by the survey area OOL-06. Survey area OOL-07 consists of a deposit of soils excavated from the area of the ISFSI and ISFSI haul road. The soil deposited in OOL,07 partially covers the footprint of a septic system leach field that serves the Administration Building/Training Center.

History: Survey Area OOL-07 has received excavation spoils from certain YNPS site modifications performed over the history of the YNPS site. Although a majority of the spoils were assessed for radioactive material content prior to deposition in OOL,07 with a "no detectable activity" result, no location specific data has been collected in this Survey Area.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-07 are Co-60, Cs-137, Sr-90 and Ag-108m.

2. Media: Surface and subsurface soil

3. Continued Investigation: Continued investigation may be necessary to assess surface and subsurface soil.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OOL-02 include the addition of soil excavated during construction of the ISFSI haul road.

2. Planned: Future-decommissioning activities may include removal of certain soils depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the currentlbest information indicating the radiological conditions and on conditions and events identified in the operating history 7-46

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision and as a result of the decommissioning activities perforned to date, survey area OOL-07 is identified as a Class 2 Area.

YNPS Site Impacted Perimeter Zone (OOL-08)

==

Description:==

OOL.08 consists of the land area owned by YAEC. OOI,08 is bounded by OOL-06, OOL,02, OOL-l0, OOL-09, OOL-ll, OOL-12, OOL- 14 and OOL-15 on the north, and by the non-impacted area on the east, west and south. The surface of OOL-08 is indigenous soils.

History: Survey Area OOL-08 represents that portion of the YNPS site that may have been impacted by wind born transmigration of radioactivity from the YNPS site that is not captured within the bounds of another survey area. OOL-08 forms a wide buffer zone between the plant industrial area and that portion of the site designated as non-impacted.

Scoping samples of various survey media in OOL-08 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-08 are Co-60, Cs-137, Sr-90, Ag-108m and H-3.

2. Media: Surface soil.

3. Continued Investigation: Continued investigation may be necessary to assess surface soil.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-08.

2. Planned: Future-decommissioning activities may include removal of certain soils depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-08 is identified as a Class 3 Area.

Southeast Construction Fill Area (OOL-09)

==

Description:==

OOL09 consists of the land area owned by YAEC. OOL09 is bounded on the north, east and south by survey area OOL.-08 and on the west by survey area OOL-I0.

History: Survey Area OOL09 has received construction spoils and certain discarded material previously used at YNPS. A comprehensive radiological assessment of this Survey Area has been performed with subsurface objects being located by ground penetrating radar. These objects were exumed and surveyed for radioactive material, in addition numerous test pits were excavated and assessed. No radioactive material was 7-47

YNPS Historical Site Assessment Revision 0 discovered in the material, soils or groundwater obtained from this area. The area is currently operated as a landfill and ground water is being monitored. Scoping samples of various survey media in OOL-09 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-09 are Co-60, Cs-137, Sr-90, Ag-108m and H-3.

2. Media: Surface and subsurface soil, surface water and groundwater.

3. Continued Investigation: Continued investigation will be necessary to assess surface and subsurface soil, surface water and groundwater.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OOL-09 include the addition of soil excavated during construction of the ISFSL and haul road.

2. Planned: Future decommissioning activities may include removal of certain soils and materials depending upon the results of the continuing investigation and requirements for further cleanup of the area related to non-radioactive materials.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey and access to surface water and groundwater.

Classification Statement: Based upon the currentibest information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-09 is identified as a Class 3 Area.

ISFSI Pad Access Zone (OOLI0)

==

Description:==

OOL- 10 consists of the land area owned by YAEC. OOL- 10 is bounded by OOL-02, NOL,06, NOL-05, NOL,04, NOL,03 and OOL, 11 on the north, OOL,08 and OOL-09 on the east, OOL-08 on the south and also on the west.

History: Survey Area OOL- 10 is the buffer zone around the RCA and, as such, has the potential to have become contaminated.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-I0 are Co-60, Cs-137, Sr-90, Ag-108m and -3.

2. Media: Surface and subsurface soil, surface water and groundwater.

3. Continued Investigation: Continued investigation will be necessary to assess surface and subsurface soil surface water and groundwater.

7-48

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OO-10 consist of soil removal to adjust the grade of the ISFSI fuel transfer haul road.

2. Planned: Future-decommissioning activities may include removal of certain soils and materials depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey and access to surface water and groundwater.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-1I is identified as a Class 2 Area.

East RCA Buffer Zone (OOL-1 1)

==

Description:==

OOL-I consists of the land area owned by YAEC. OLk- 1 is bounded by OOL- 12 on the north, OOL-08 on the east, OOL- 10 on the south and NOL_02 and NOL-03 on the west.

History: Survey Area 00k-i1 is the buffer zone around the RCA and, as such, has the potential to have become contaminated.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-Il are Co-60, Cs-137, Sr-90, Ag-108m and H-3.

2. Media: Surface and subsurface soil.

3. Continued Investigation: Continued investigation will be necessary to assess surface soil.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in OOL-il.

2. Planned: Future-decommissioning activities may include removal of certain soils and materials depending upon the results of the continuing investigation.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL- II is identified as a Class 2 Area.

Warehouse Rail Spur (OOL- 12)

==

Description:==

OOL- 12 consists of the land area owned by YAEC, in the yard area within the current industrial area of the YNPS site extending from the east line of the RCA to the YAEC, US Gen property line. Survey Area OOL- 12 is bounded by the Service Building and warehouse, OOL-02 and the YAEC, US Gen property line on the north, 7-49

a-YNPS Historical Site Assessment Revision 0 00L 13 and 00L 14 on the east, 00L-08 and OOLl 1I on the south and NOL-01 on the west.

History: Survey Area OOL- 12 has received surface run-off from the east end of the RCA and has been a travel path for radioactive material received at or shipped from the YNPS site. Contaminated surface soil has been removed from OOL,12 during plant operations.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area 00L-12 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface and subsurface soil.

3. Continued Investigation: Continued investigation will be necessary to assess subsurface structures and systems.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in 00-L02 include the installation of the Auxiliary Service Water system.

2. Planned: Future decommissioning activities may include removal of certain surface and subsurface structures and systems

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area 00L-12 is identified as a Class I Area.

US Gen Rail Spur Terminus (OOL-13)

==

Description:==

OOL 13 consists of the land area owned by US Gen. Survey Area OOL 13 is bounded by Sherman Reservoir on the north, OOk 15 on the east, the YAEC survey Area 00L-14 on the south and 00L12 on the west.

History: Survey Area 00L-13 has received surface run-off from the 0OL 12 and has been used as a path of travel for radioactive material received at and shipped from the YNPS site.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL 13 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface and subsurface soil.

3. Continued Investigation: Continued investigation will be necessary to assess surface and subsurface soil.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-13.

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YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision

2. Planned: Future-decommissioning activities may include removal of certain soils.

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events idertified in the operating history, survey area OOL-13 is identified as a Class 1 Area.

US Gen Wheeler Brook Frontage (OOL-14)

==

Description:==

OOL-14 consists of the land area owned by US Gen. Survey Area OOL-14 is bounded by OOL-13 on the north, OOL-15 and OOL-08 on the east, OOL-08 on the south and also on the west.

History: Survey Area 0OL-14 at one time was included within the security fence of the YNPS site OOL-14 serves as a buffer zone between survey areas OOL-12 and OOL-13.

Scoping samples of various survey media in OOL- 14 indicate mean levels of radioactivity to be a small fraction of the proposed soil DCGLs (see Table 2-5).

Although OOL-14 abuts class I area OOL-13, the mode of contamination of OOL-13 was by surface water run-off from the RCA. OOL-14 is above the grade level of OOL-13 and was not impacted by the surface run-off transmigration vector.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-14 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface soil.

3. Continued Investigation: Continued investigation will be necessary to assess surface soils.

Decommissioning/Decontamination Activities

1. Performed: Decommissioning activities performed in OOL-02 include placement.

of LP Gas storage tanks.

2. Planned: Future decommissioning activities include removal the LP Gas tanks from survey area OOL-14

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL-14 is identified as a Class 3 Area.

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YNPS Historical Site Assessment Revision 0 US Gen Sherman Reservoir East Shoreline (OOL, 15)

==

Description:==

OOL- 15 consists of the land area owned by US Gen. Survey Area OOL- 15 is bounded by Sherman Reservoir (OOL-O1) on the north, US Gen owned non-impacted area on the east, OOL-08 on the south and OOL- 14 and OOL- 13 on the west.

History: Survey Area OOL- 15 serves as a buffer zone to survey area OOL- 13.

Although OOL- 15 abuts class 1 area OOL- 13, the mode of contamination of OOL- 13 was by surface water run-off from the RCA. OOL, 15 is above the grade level of OOL, 13 and beyond the Wheeler Brook surface run-off terminus. OOL- 15 was not impacted by the surface run-off transmigration vector that impacted CCL- 13.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL-15 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface soil.

3. Continued Investigation: Continued investigation will be necessary to assess surface soils.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-15.

2. Planned: No decommissioning activities are anticipated for survey area OOL, 15

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL- 15 is identified as a Class 3 Area.

Yankee House Parking (OOL- 16)

==

Description:==

OOL- 16 consists of the land area owned by YAEC and is entirely bounded by non- impact area.

History: Survey Area OOL- 16 received soil from the YNPS site for the purpose of leveling the parking area. Although the soil originated in areas that are impacted (class 3 areas), soils from these areas typically show levels of radioactivity at a small fraction of the proposed soil DCGLs.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area CCL- 16 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface soil.

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Revision Revision 00 YNPS Historical Site Assessment YNPS Historical Site Assessment

3. Continued Investigation: Continued investigation will be necessary to assess surface soils.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-16.

2. Planned: No decommissioning activities are anticipated for survey area OOL-16

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information indicating the radiological conditions and on conditions and events identified in the operating history, survey area OOL- 16 is identified as a Class 3 Area.

Asphalt Brick and Concrete Storage Area (OOL-17)

==

Description:==

OOL- 17 consists of the land area owned by YAEC. Survey Area OOL- 17 is bounded entirely by non- impact area.

History: Survey Area OOL- 17 received asphalt and concrete from the YNPS site.

Materials deposited in this area were subjected to radiological survey for free release prior to being transported to OOL-17. Based on the origin of this material the area must be classified as impacted. It is anticipated that any residual radioactivity, if present would not exceed a small fraction of the proposed soil DCGLs.

Contamination:

1. Radionuclides Potentially Present: The primary radionuclides of concern for survey area OOL- 17 are Co-60, Cs-137, Sr-90 and H-3.

2. Media: Surface soil.

3. Continued Investigation: Continued investigation will be necessary to assess surface soils.

Decommissioning/Decontamination Activities

1. Performed: No decommissioning activities have been performed in survey area OOL-17.

2. Planned: No decommissioning activities are anticipated for survey area OOl 17

3. Anticipated End State Configuration: A soil surface configuration suitable for survey.

Classification Statement: Based upon the current/best information' indicating the radiological conditions and on conditions' and events identified in the operating history, survey area OOL-17 is identified as a Class 3 Area.

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- U-YNPS Historical Site Assessment Revision 0 7.4 ContaminatedMedia Media contaminated as a result of normal plant operations and unplanned release events include:

• Soil, contaminated as a result of direct release of contamination to the surface soil from spills of liquid or deposited as a result of material transport by wind water or wildlife.

• Subsurface soil, as a result of surface contamination infiltration or subsurface leakage from structures.

• Asphalt, contaminated as a result of direct release of contamination on to the surface or as a result of re-distribution of surface contamination due to surface water run-off.

• Concrete, contaminated as a result of direct release of contamination on to the concrete or as a result of contamination spread associated with personnel traffic and material transport.

• Paint, as a result of direct release of contamination to painted surfaces by liquid and air borne particulate contamination.

• Roofing material contaminated as a result of direct release of contamination to roof surfaces.

The potentially contaminated media remaining at the conclusion of decommissioning activities will be limited to:

• Surface Soil

• Subsurface Soil

• Asphalt

• Concrete

• Ground Water 7.5 Related Environmental Concerns An investigation to define the potential or confirmed areas of environmental concern at the YNPS was concluded on January 27,1998. Areas of environmental concern were identified by record review, site reconnaissance, and personnel interviews. The results of this investigation are reported in Historical Non-Radiological Environmental Site History Report prepared for, YNPS by, Applied Enviro-Tech, Inc January 1998.(Reference 23)

Related environmental hazards identified include:

• Septic discharge areas

• Underground storage tanks for gasoline, heating oil and waste oil

• A construction/demolition material area

• Outside material storage areas

• Parking areas

• Fire extinguisher training area

• Location of electrical transformers

• Loading areas 7-54

YNPS Historical Site Assessment Revision 0

• Subsurface piping

• Above ground storage tanks

• Herbicide and pesticide areas Environmental concerns associated with plant structures include:

• Lead paint

• PCB paint

• Asbestos paint

• Asbestos pipe insulation, roofing paper, window caulking and floor tiles

• Gal-bestos building siding

• Bituminous roofing materials

• Lead shieldings Environmental concerns associated with plant operations includes:

Chromate Boric acid Water treatment chemicals Caustic decontamination solutions Acid decontamination solutions Diesel fuel Fuel oil Gasoline Greases Paints Solvents 7-55

YNPS Historical Site Assessment Revision 0 Table 7-1 Floor and Total Area of Buildings and Features SURVEY AREA DESCRIPTION MARSSIMI FLOOR TOTAL AREA RATIO (total:

CLAS.S AREA (mn2 ) (M foor)

SVC-01 NORTH PART OF SERVICE BLDG (CLEAN SIDE) 3 921 921 1 SVC-02 RAD PORTIONS OFSERVICE BLDG AND ANNEX _ 444 444 SVC-03 CLEAN SIDE OF SERVICE BLDG ANNEX 3 366 366 TBN-0I TURBINE BLDG AND OFFICE PADS 3 1517 1517 SPF-01 SPENT FUEL POOL AND TRANSFER CHUTE 1 60 302 5.03 SPF-02 NEW FUEL VAULT I 95 141 1.48 BRT-01 CONCRETE PEDESTALS. PAD AND ANNULUS 1 2095 2095 NSY-0 I NORTH AND SOUTH DECON PADS AND FTE - 224 224 I NSY-02 IX-PIT, VALVE GALLERY/ PAB STAIRWAY - 95 390 4.1 NSY-03 Si DIESELUACCUMULATOR TANKIBATTERY ROOM I 380 482 1.12 NSY-04 SAFE SHUTDOWN 1 103 120 1.16 NSY-05 FIRE WATERTANKAND PUMP HOUSE 1 184 184 1 NSY-06 PCA#2 (NEW) 1 219 219 1 NSY-07 WHT / ADT / WASTE GAS PADS 1 390 390 1 NSY-08 NEW SITANK 1 80 80 1 NSY-09 ELEVATOR SiHAFT I 6 21 4.5 NSY- I0 ISFSI 3 985 1078 1.09 NSY-I I CHEM WASTE PIT I 17 78 4.5 NSY- 12 TANK #1 BASE 1 31 31 1 NSY-I 3 TANK #39 BASE 1 70 70 1 WST-01 PCA#I(OLD) 1 109 109 _

WST-02 PCA WAREHOUSE I 604 604 1 WST-03 WASTE DISPOSAL BLDG 1 230 437 1.9 WST-04 COMPCTOR BLDG 1 165 165 AUX-01 PAB/ EAST END I 289 772 2.6 AUX-02 PAB / WEST END I 130 189 1.45 OMB-01 PUMPHOUSE AND SCREENWELL 3 230 541 2.35 OMB-02 SECURITY GATEHOUSE AND DIESEL GENERATOR 3 270 868 3.2 OMB-03 ADMINISTRATION BUILDING 3 297 798 2.6 OMB-04 WAREHOUSE AND LOADING DOCK PAD 3 625 625__

OMB-05 FURLON HOUSE 3 432 1076 2.5 OMB-06 SEALPIT 3 120 329 2.74 7-56

( (

YNPS License Tennination Plan Revision 0 TABLE 7-2 Area of Open Land Survey Areas SURVEY DESCRIPTION MARSSIM AREA AREA CLASS (m2)

OOL-01 SHERMAN POND SEDIMENTS 3 73971 OOL-02 YANKEE NON-RAD YARD AREAS 3 7134 OOL-03 SHERMAN RESERVOIR DAM AND SOUTH 3 16177 SHORELINE

OOL-04 US GENERATION / SHERMAN STATION 3 17870 OVERLYING GROUNDWATER PLUME .

OOL-05 US GENERATION / DEERFIELD RIVER 3 28574 FRONTAGE OOL-06 YANKEE WESTERN ACCESS 3 37281 OOL-07 SOILS DEPOSIT AREA 2 2108 OOL-08 YANKEE SITE EXCLUSION ZONE -3 133368 OOL-09 SOUTHEAST CONSTRUCTION FILL AREA 3 2387 OOL-10 ISFSI/ACCESS, EXCLUSION ZONE, 2 8408 BUFFER ZONE : _

OOL-1 1 EAST RCA BUFFER ZONE 2 1220 OOL-12 WAREHOUSE RAIL SPUR 1 S: 876 OOL-13 US GENERATION/RAIL SPUR TERMINUS 1 1148 OOL-14 US GENERATION/WHEELER BROOK 3 2354 FRONTAGE . ,

OOL-15 US GENERATION/SHERMAN RESERVOIR 3 4662 EAST SHORELINE OOL-16 FURLON HOUSE PARKING LOT 3 2481 OOL-17 ASPHALT, BRICK AND CONCRETE 3 3247 STORAGE YARD . .

NOL-01 EASTERN LOWER RCA YARD .I-: 1364 NOL-02 NORTHEASTERN UPPER RCA YARD 1 1990 NOL-03 SOUTHEASTERN UPPER RCA YARD 1 1575 NOL-04 SOUTHWESTERN UPPER RCA YARD 1 1753 NOL-05 NORTHWESTERN UPPER RCA YARD 1. 1586 NOL-06 WESTERN LOWER RCA YARD 1 1329 NOL-07 ISFSI RCA YARD 3 1717:

7-57

a~

YNPS Historical Site Assessment Revision 0 TABLE 7-3 Current Radiological Conditions of Buildings in the Industrial Area by Survey Area Survey Description Nominal Nominal loose area exposure rate surface (pr/hr) contamination (dpm/100cmd)

SVC-01 NORTH PART OF SERVICE BLDG (CLEAN 8 <1000 SIDE).

SVC-02 RAD PORTIONS OF SERVICE BLDG AND 8 <1000 ANNEX SVC-03 CLEAN SIDE OF SERVICE BLDG ANNEX 6 <1000 TBN-01 TURBINE BUILDING AND OFFICES 10 ,<1000 SFP-01 SPENT FUEL PIT AND TRANSFER CHUTE 500-10,000 300-8700 SFP-02 NEW FUEL VAULT 100-5000 <1000 BRT-01 CONCRETE PEDESTALS, PAD AND 15 <1000 ANNULUS NSY-01 NORTH AND SOUTH DECON PADS AND 20-700 >1000 FTE NSY-02 IX-PIT, VALVE GALLERY/ PAB STAIRWAY 300 <1000 NSY-03 SI DIESEL/ACCUMULATOR 11 <1000 TANKIBATTERY PADS NSY-04 SAFE SHUTDOWN SYSTEM BUILDING 10 <1000 NSY-05 FIRE WATER TANK AND PUMP HOUSE 13 <1000 NSY-06 PCA#2 (NEW) 10 <1000 NSY-07 WHT / ADT / WASTE GAS PADS 40 <1000 NSY-08 NEW SI TANK 20 <1000 NSY-09 ELEVATOR SHAFT 500 <1000 NSY-10 ISFSI 2000-5000 <1000 NSY-11 CHEM-WASTE TRANSFER PUMP PIT 2000 - 15000 >1000 NSY-12 TANK #1 BASE AND PIPECHASE 15 <1000 NSY-13 DEMIN WATER STORAGE TANK #39 2500 <1000 BASE WST-01 PCA #1 (OLD)30-200 <1000 WST-02 PCA WAREHOUSE 60-150 >1000 WST-03 WASTE DISPOSAL BLDG 15 <1000 WST-04 COMPCTOR BLDG 20 <1000 AUX-01 PAB/ EAST END 10 <1000 AUX-02 PAB /WEST END 10 <1000 7-58

YNPS Historical Site Assessment Revision 0 TABLE 7-3 (Con't)

Survey Description Nominal Nominal loose area exposure rate surface (urlhr) contamination

.__ _ .(dpm/100cmd)

OMB-01 PUMPHOUSE AND SCREENWELL 11. <1000 SECURITY GATEHOUSE AND DIESEL. 6 < 1000 OMB-02 GENERATOR ._;__

OMB-03 ADMINISTRATION BUILDING No data <1000 OMB-04 WAREHOUSE AND LOADING DOCK 6 <1000 OMB-05 FURLON HOUSE i No Data <1000 OMB-06 SEAL PIT No Data <1000 Note: The entries in BOLD in the table are either currently in use or the reported exposure rates are influenced by adjacent buildings or tanks that are currently in use.

7-59

YNPS Historical Site Assessment Revision 0 Table 7-4 Summary of Radiological Conditions of Open Land Areas (SOF = Sum of Fractions of Soil DCGLs )

Survey Description MARSSIM Medium SOF SOF SOF Area class (min) (max) (mean)

OOL-01 SHERMAN POND 3 Sediment 0.004 0.287 0.098 SEDIMENTS OOL-02 YANKEE NON-RAD 3 Soil 0.002 0.045 0.018 YARD AREAS OOL,03 SHERMAN 3 Sediment 0.160 0.160 0.160 RESERVOIR DAM Soil 0.004 0.332 0.036 AND SOUTH SHORELINE OOL-04 USGEN / SHERMAN 3 Sediment 0.009 0.009 0.009 STATION Soil 0.006 0.035 0.020 OVERLYING GROUNDWATER PLUME OOL-05 USGEN/ DEERFIELD 3 Sediment 0.009 0.107 0.038 RIVER FRONTAGE Soil 0.001 0.034 0.018 OOL-06 YANKEE WESTERN 3 Sediment 0.007 0.047 0.022 ACCESS Soil 0.004 0.080 0.029 OOL-07 SOILS DEPOSIT AREA 2 no data ok__

OOL-08 YANKEE SITE 3 Sediment 0.005 0.019 0.010 EXCLUSION ZONE Soil 0.004 0.345 0.051 OOL-09 SOUTHEAST 3 Soil 0.004 0.113 0.022 CONSTRUCTION FILL Asphalt 0.014 0.153 0.077 AREA OOL- 10 ISFSI/ACCESS, 2 Soil 0.003 0.391 0.027 EXCLUSION ZONE, BUFFER ZONE OOL- 11 EAST RCA BUFFER 2 no data ZONE OOL-12 WAREHOUSE RAIL I Soil 0.013 0.013 0.013 SPUR OOL-13 USGEN/RAIL SPUR I Soil 0.004 0.031 0.014 TERMINUS OOL- 14 USGEN/WHEELER 3 Soil 0.004 0.030 0.014 BROOK FRONTAGE OOL-15 USGEN/SHERMAN 3 Soil 0.007 0.017 0.012 RESERVOIR EAST SHORELINE 7-60

YNPS Historical Site Assessment Revision 0 Table 7-4 Summary of Radiological Conditions of Open Land Areas (SOF = Sum of Fractions of Soil DCGLs)

Survey Description MARSSIM Medium SOF SOF SOF Area class ( (m ax) (mean)

OOL-16 FURLON HOUSE 3 no data PARKING LOT OOL-17 ASPHALT, BRICK 3 no data AND CONCRETE STORAGE YARD .

EAST LOWER RCA 1 Soil 0.004 0.513 0.153 NOL-01 YARD _

NORTHEASTERN 1 Soil 0.002 0.422 0.079 NOL-02 UPPER RCA YARD SOUTHEASTERN I Soil 0.003 224.5 4.3 NOL-03 UPPER RCA YARD SOUTHWESTERN 1 Soil 0.005 0.676 0.099 NOL-04 UPPER RCA YARD NORTHWESTERN I Soil 0.003 0.133 0.021 NOL-05 UPPER RCA YARD WEST LOWER RCA 1 Soil 0.003 0.402 0.074 NOL-06 YARD NOL-07 ISFSI RCA YARD 3 Soil 0.003 0.15 0.006 7-61

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 Table 7-5 Radionuclides of Concern At YNPS H-3 Tc-99 Eu-1 55 C-14 Ag-108m Pu-238 Fe-55 Sb-125 Pu-239,240 Co-60 Cs-134 Pu-241 Ni-63 Cs-1 37 Am-241 Sr-90 Eu-1 52 Cm-243,244 Nb-94 Eu-1 54 7-62

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision Kj 8 References

1. NUREG-1575: Multi-Agency Radiation Survey and Site Investigation Manual, Revision 1,!dated August 2000 -

2. Possession Only License (POL) No. DPR-3

3. USGS 7.5 minute quadrangle map Rowe Massachusetts - Vermont (42072-F8-TF-024, 1973, DMA III NW-SERIES V814).

4. Environmental Characterization Summary, Yankee Nuclear Power Plant Site, June 2000.

5. Decommissioning Environmental Report

6. YAEC Deed Study Project Rowe and Monroe, Massachusetts, dated December 18, 1998.

7. YNPS License Termination Plan, dated December 1997 (withdrawn in May 1999).

8. YNPS Decommissioning Plan, dated March 29, 1994.

9. DRAFT NUREG/CR-5849 (ORAU 92/C57): "Manual for Conducting Radiological Surveys in Support of License Termination," by J.D. Berger, dated June 1992.

10. Yankee Nuclear Power Station, Systems Training Manual.

11. Plant Superintendent's "Monthly Operating Reports" Number 1, February 1961 through Number 120, December 1970.

12. Condition Report 03-259, 'While down ending a fuel rack in the rad waste warehouse, several gallons of potentially contaminated water were released onto the floor," dated June 19, 2003.

13. Technical Basis Document YA-REPT-00-006-03, "Statistical Evaluation of Non.

Impacted Area, Evaluation of 137Cs Concentration in Soils of Non-impacted and Reference Areas in the Vicinity of YNPS."

14. EG&G 10617-1233, UC-702, "An Aerial Radiological Survey of the Yankee Rowe Nuclear Power Station and Surrounding Area," EG&G Energy Measurements, dated September 1993.

15. YRC-1 178, Radionuclide Soil Concentrations Surrounding YNPS Resulting from Gaseous Release During Plant Operation, dated March, 1998.

16. NCRP Report 47 "Tritium Measurement Techniques," dated May 28, 1976.

I -. - . 8.1,. - -

0 YNPS Historical SiteAssessment- Revision 00

..Revision YNPS Historical Site Assessment

17. NCRP Report 50 "Environmental Radiation Measurements," dated December 27, 1976.

18. NCRP Report 81 "Carbon-14 in the Environment," dated May 15, 1985.

19. Technical Basis Document YA-REPT-00-001-03, Radionuclide Selection for DCGL Determination, dated November 5, 2003.

20. Yankee Nuclear Plant Site License Termination Plan (LTP), Revision 0, dated November 2003.

• .IL ,P 8-2

YNPS Historical Site Assessment Revision 0 0

YNPS Historical Site Assessment Revision Appendix Al History of Plant Gaseous Releases Li i

rI - 1. i

- I . I

. f I

. Page 1 f 8 - - - - .

0 YNPS Historical Site Assessment Revision 0 Over the lifetime of the plant a number of gaseous release events have occurred. These events were non-routine releases from the plant. None of these events contributed in a significant manner to the residual contamination at YNPS. Following are short descriptions of these gaseous events.

AOR # Description 62-15 Gas Release from Gas Surge Drum 10/26/62 62-17 Gas Release from Waste Gas Surge Drum 12/28/62 64-07 Waste Disposal Cover Gas Release to Primary Vent Stack 8/5/64 65-04 Waste Disposal Plant Cover Gas Release 2/14/65 65-10 LPST Gas Leak Via Broken Test Connection 5/10/65 66-01 Inadvertent Release of Waste Disposal Cover Gas to Primary Vent Stack 1/27/66 67-03 Inadvertent Gas Release from Low Pressure Surge Tank 4/4/67 67-13 Waste Disposal Mis-operation and Subsequent Gas Release 12/6/67 69-07 Inadvertent Gas Release from Low Pressure Surge Tank 11/18/69 71-03 Waste Gas Leakage 8/30/71 71-04 Waste Gas Leakage 9/17/71 72-07 Inadvertent Radioactive Gas Release from Waste Liquid Evaporator 6/2/72 73-01 Breach of VC Integrity Resulting in Release of Airborne Activity 4/2/73 74-01 Uncontrolled Release of Radioactive Gas from' Waste Gas Surge Drum 2/27/74 75-08 Vapor Container Leakage 8/15/75 PIR # Description 76-04 Unintentional Release of Radioactive Gas from Waste Gas Cover 3/20/76 76-06 Vapor Container Leak 4/8/76 76-11 Vapor Container Air Leak 7/9/76 82-14 Inadvertent Gas Release via Waste Gas System Loop Seal 9/23/82 82-18 Waste Gas Surge Drum Gas Release 11/16/82 83-07 Gaseous Release via Primary Vent Stack 3/5/83 83-09 Radioactive Gas Release 3/16/83 83-16 Unplanned Radioactive Gas Release 6/23/83 83-20 Radioactive Gas Release 10/20/83 83-23 Radioactive Gas Release 11/28/83 84-12 Waste Gas System Loop Seal Blow-by 6/25/84 84-13 Radioactive Gas Release While Performing OP-2159 7/14/84 84-14 Iodine Release During Main Coolant Loop #4 Purge 7/15/84 87-01 Inadvertent Release of LPST Cover Gas 5/4/87 LER # Description 77-21 Primary Containment Excessive Air Leakage 4/20/77 77-23 Waste Gas System Leak 4/26/77 82-25 Waste Gas Decay Drum Valve Leak 8/31/82 Page2of8

YNPS Historical Site Assessment *Revision 0 YNPS Historical Site Assessment Rcvision 0 Gas Release from Gas Surge Drum - On October 26, 1962 approximately one volume at STP of the Gas Surge Drurn was released due to low water level in the loop seal. The line to the low water alarm was partially blocked preventing an alarm. Radiation monitoring records show that the radioactivity level of the gas released was insignificant.

AOR 62-15..

Gas Release from Waste Gas Surge Drum- On December 28, 1962 the drain valve on the waste gas surge drum loop seal, after being opened for a weekly check, was closed again but did not seat properly. This allowed the loop seal to drain and allowed a calculated 800 ft3 of gas containing 3 x 10.2 ttCi/cc of noble gas to be released. . The original gas volume was further diluted by make up air as the gas entered the release pathway resulting in a final maximum concentration of 1 x 10-4 [Ci/cc to be released.

AOR 62-17.

Waste Disposal Cover Gas Release to Primary Vent Stack - On August 5, 1964 due to an incorrect valve lineup Waste Disposal Cover Gas was bled to the vent stack over a period of time. Due to the low activity level the stack monitor did not alarm. Oer a 171/2hour period 3140 ft3 of gas containing 13.2 x 104[jCi of Xel3 3 was released. The released gas had a specific activity of 1.5 x 10-3.,tCi/cc Xel'3 3 which, diluted with 15,000 cfm from the stack fan, made the release to the environs 3.0 x 1010 tCi/cc Xe' 33 . AOR 64-07.

Waste Disposal Plant Cover Gas Release - On February 14-15; 1965 radioactive gas was released from the waste disposal plant evaporator to the outside through open valves and an open window in the evaporator cubicle, -1450 ft3 of gas was released. A sample of the remaining cover gas showed 2.3 x 10-5 pCi/cc of Xe'3 3 . Total activity released was

-943 pCi. AOR 65-04.

LPST Gas Leak via Broken Test Connection in Vent Discharge Line During Normal Gas Pressure Reduction- On May 4, 1965 a broken test connection on the vent line to the LPST allowed 16 ft3 of gas to escape to the vent stack. The gross gaseous concentration was 2.83 x 10-5 gCi/cc. A calculated 43 mCi of Ar4 1, Xe' 33 and Xe13 5 plus an estimated 4.5 mCi of tritium was released. Later sample results showed 0.427 x 10 8 OCi/cc Xe'3 3 ,

35 3 0.507 x I0-8 ptCi/cc Xe1 , 0.267 x 10-8 gCi/cc H and 1.629 x IO-8 pCi/cc Ar ' was4 vented out the stack. AOR 65-10.. *

• . 7 Inadvertent Release-of Waste Disposal Cover Gas to the Primary Vent Stack- On January 27, 1966 while removing the waste disposal gas blanket from the Primary Drain Collecting Tank for maintenance, it was noticed that the cover gas system pressure maintenance valve was partially open, indicating a possible system leak. Upon ceasing.

the operation and closing the PDCT vent to the stack the makeup valve closed indicating there had been a release. It was discovered that the fission gas drain line was the origin of the leak, terminating inside the PDCT near the top above the water line. With the fission gas drain valve closed the leak stopped. A sample of the waste disposal cover gas showed principle isotopes of 1.0 x I0- gCi/cc Xe'3 3 and 1.0 x 10-2 pCi/cc tritium. Inventory of the system indicated a possible release of 500 ft3. The total release was 142 gCi of Xe 133 Page 3 of 8

YNPS Historical Site Assessment Revision 0 YNPS Historical Site Assessment Revision 0 and 142 mCi of tritium. Specific activities after dilution in the stack were 8.3 x 10-12 pCi/cc for Xe 133 and 8.3 x 10-9, Ci/cc for tritium. AOR 66-01.

Inadvertent Gas Release from Low Pressure Surge Tank - On April 4, 1967 while sanpling the LPST the valve in the direct line to the LPST was left open, thereby allowing backflow from the tank to the sample hood. The amount of radioactivity released from the stack after dilution was 1.92 x 10.10. 0Ci/cc Ar41, 7.58 x 10-11 gCi/cc Xe133 , 2.78 x 10-10 p0Ci/cc Xe'3 5 and 9.49 x 10.1O0 pCi/cc tritium. All were less than MPC. AOR 67-03.

Waste Disposal Mis-operation and Subsequent Gas Release - On December 6, 1967 incorrect valving during a routine evaporator processing operation on the waste holdup tank allowed a release to the stack of 30 ft3 of cover gas. The concentrations were 3.53 x IO-5 pCi/cc Xe' 3 3 , 1.15 x 10- pCi/cc Xe135, 4.28 x 10 pCi/cc Ar4 ' and 2.4 x 104 p0Ci/cc tritium. Following dilution in the stack over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period the amounts released were 1.10 x 10.8 iiCi/cc Xe133, 3.59 x 10'9,uCilcc Xe135, 1.34 x 10.8 0Ci/cc Ar41 and 7.5 x 10.8 pCi/cc tritium. All were less than MPC. A total activity of 280 ,Ci was contained in the 30 ft3. AOR 67-13.

Inadvertent Gas Release from Low Pressure Surge Tank - On November 18, 1969, due to the incorrect opening of a valve during sampling of the pressurizer, 47.6 ft of gas was inadvertently released to the stack. A sample of the gas phase showed 2.32 mCi Ar41, 2.91 mCi Xe' 33 , 0.49 mCi'Xe13 5 and 13.5 mCi tritium were release'd which, after stack dilution, was 1.37 x 10.1O0 Ci/cc Ar41, 1.72 x 10-10 ,uCi/cc Xe' 3 3, 2.90 x 10'" gCi/cc Xe13 5 and 7.95 x 10.10 ,Ci/cc tritium. All releases were less than MPC. AOR 69-07.

Waste Gas Leakage - On August 30, 1971 after a review of waste gas pressure data on the operational logs it was determined there was a small leak in the system, which was later found in the hydrogen analyzer cabinet and repaired. Conservative calculations showed

-2700 ft3 of gas was released. The total estimated release was 8.56rmCi Xe'3 3 , 17.6 mCi H3 and 2.52 mCi C The' final concentrations of the radionuclides released were 1.02 x 10'9p.11cc' Xe'3 3 , 2.09 x 10-9 pCi/cc H3 and 3.00 x 10.10 pCi/cc Cd4. All releases were less than MPC. AOR 71-03.

Waste Gas Leakage - On September 17, 1971 leaks were'found in the waste gas system. The amounts released were 0.066 mCi Xe13 3, 0.664 mCi IH and 0.095 mCi C14. The released concentrations were 4.54 x 10" .Ci/cc Xe13 3, 4.55 x 10.10 p.0/cc H3 and 6.53 x1

,uCi/cc C14. All releases were less than MPC. AOR 71-04.

Inadvertent Radioactive Gas Release from Waste Liquid Evaporator- On June 1-2, 1972

' two valves were left in the incorrect position for processing of Class 1 liquids. A total activity of75.8 pCi of Xe'3 3 was released. The released'oncentration of this radionuclide was 2.24 x 10.10 pCi/cc. This was below Tech Spec limits. AOR 72-07.

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YNPS Historical Site Assessment Revision 0O.

YNPS Historical Site Assessment Revision 0.

Breach of Vapor Container Integrity Resulting in Release of Airborne Activity - On April 2, 1973 both doors of the VC personnel hatch were left open, an incorrect configuration in that the plant condition required that containment integrity be maintained and at least one door be closed at all times. The door remained open for two minutes and 12,560 ft3 of air containing 82.3 giCi of tritium was released . When averaged over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> this amounted to 3.2 x 10-1o p Ci/cc, which was below MPC. AOR 73-01.

Uncontrolled Release of Radioactive Gas from the Waste Gas Surge Drum - On February 27, 1974 during routine sampling of the waste gas surge drum, leakage from the system was suspected. A leak was verified from a valve bonnet at a rate of 1 cc/sec and repaired.

The following radionuclide concentrations were calculated at the site boundary using a dispersion factor of 1.24 x 10-5 sec/n? :: , -

Nuclide Waste Gas Surge Concentration at -MPC - Total Activity Drum Concentration the Site Boundary (pCi/cc) Released in 63 (ACi/cc) (ACi/cc) Days (gCi) 7 Fe'= -3.7.x 10- 4.6 x 10. .3 x 10' f 200,000 Xe x 10-5.2 6.5 x I0' 1 X10-1i 2800

-1.75 x 10 2.2 x10 3x10 9600 1.4 x 10 1.75 x 10; 4 I xl0'-' 7700 TV1.3 x 101.6 x 10-' 2x10 700

__Ar_717 2.02 x 104 2.5 xl0 1 x 10- 4 ' 1084 This release was 0.002% of the proposed Tech Spec Limit. AOR 74-01.

Vapor Container Leakage - On August 14, 1975 there was indication of leakagefrom the vapor container, which was found to be coming from a loose blank flange on the Low Pressure Vent Header Penetration in the upper pipe chase of the PAB. Estimated leakage through the flange was 0.4 f&/minute resulting in a total activity release'of 18.845 mCi of an unspecified gaseous mixture. AOR 75-08.

Primary Containment Excessive Air Leakage - On April 20, 1977 the daily air mass:

calculation indicated there might be an air leak from containment. The leak continued over a three-day period during which valves and flanges were tightened along the suspected release path. ' Using an estimated leak rate of 967 cc/sec and the most limiting atmospheric dispersion factor of 1.2 x l0-5 sec/nil for the west/southwest direction the total activity released in the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period was 10000 pCi Xel33 , 4000 pCi Kig5,'2300 pCi C14 and 3500 ptCi H3. LER 77-21.

Waste Gas System Leak due to Valve Ruptured Diaphragm- On April 26, 1977 'due to a failed valve diaphragm' 2400 ft3 of waste'gas was' released. The gas'contained 130,000

pCi of Xe' 3 90,000 pCi of Kr5 and 30,000 LoCi of C's. The most limitinig atmobpheric dispersion factor of 1.2 x 10- sec/n? for the west/southwest direction yielded an average

' concentrati6n of 7 x 10.12 pCi/cc at the nearest site boundary that was 0002% of MPC.

LER 77-23. ,

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YNPS Historical Site Assessment Revision O' Inadvertent Gas Release via the Waste Gas System Loop Seal Upon Failure of the No. 1&2 Waste Gas Compressors - On September 23, 1982 due to equipment failure 1200 [tCi of gas containing of Xe 3 3 , Xe 35 , Kx5 and C'4 was released. The fractional distribution of the radionuclides in the gas mixture was not reported. The concentration at the site boundary was well below allowable MPC. PIR 82-14.

Waste Gas Surge Drum Gas Release - On November 16, 1982, due to an open valve on, the Primary Drain Collecting Tank, gas was released to the stack. A total of 5161 ft3 of gas with a total activity of 0.359 Ci was released. See PIR 82-18 for actual site meteorology calculations and radionuclide distributions.

Waste Gas Decay Drum Leak on Safety Valve Line - On August 31, 1982'a pinhole leak was found in the weld that attached a capped pipe nipple to a safety valve body. The total activity released was 1.67 x 101 Ci of mixed radioactive gases (See LER 82-25 for specific breakdown of gaseous components). The total fraction of MPC at 1/2 mile was calculated to be 7.1 x 10'. LER 82-25.

Gaseous Release via Primary Vent Stack - On March 5, 1983 an incorrectly purged waste disposal evaporator released of 10,000 gCi of radioactive noble gas and its short lived particulate progeny. The origin of these gases was traced to the waste liquid evaporator process. The resulting air concentration was below Tech. Specs. PIR 83-07.

Radioactive Gas Release via the Primary Vent Stack - On March 16, 1983 a small quanitity of radioactive' noble gas and its short lived particulate progeny in 'the waste disposal overhead vent line was released. The origin of these gases was also traced to the waste liquid evaporator process. The amount released was 6.8 x 104 [tCi. The event was self-terminating. PIR 83-09.

Unplanned Radioactive Gas Release - On June 23, 1983 due to a leaking valve a steady release of 250 mCi of radioactive noble gas was released from the primary drain collecting tank to the stack. Five periods of elevated release were also observed (assumed to be of one minute duration each) and resulted in an additional 480 mCi released. The valve was set to an alternate position to stop the leak. PIR 83-16.

Indication of a Radioactive Gas Release via the Waste Gas System Loop Seal - On September 20, 1983 due to a malfunction of the #1 Waste Gas Compressor -5 ft3 of radioactive noble gas containing 2.73 mCi total activity was released. The malfunction was corrected. PIR 83-20.

Indicated Radioactive Gas Release via the PVS While Starting Evaporator- On September 28, 1983 the PVS radiation monitor alarmed due to a high level of noble gas entrained in liquids from the gravity drain tark being processed in the liquid waste evaporator. The iodine channel of the PVS radiation monitor also alarmed during this event. Chemistry Department analysis indicated that less than 1 gCi of 1131 was released. Subsequent investigation indicated that the iodine channel window was not properly adjusted and was receiving signal due to noble gas. PIR 83-23 Page 6 of 8

YNPS Historical Site Assessment -.- ~Revision 00 Revision YNPS Historical Site Assessment Waste Gas Loop Seal Unplanned Releases - On June 25, 1984 oscillations in the loop seal allowed a small gas release, 3.61 x 10-10 [tCi/cc of Xe'3 3. The total activity was 34.8 mCi.

On June 26, 1984 while bleeding gas from the high to low pressure side of the waste gas system, a valve was mispositioned allowing another small gas release. The maximum offsite concentration was 1.77 x 10-9 pCi/cc. PIR 84-12.

Radioactive Gas Release While Performing OP-2159, "Removal of the Hydrogen Blanket from the Low Pressure Surge Tank" - On July 14, 1984, while performing OP-2159, higher than normal activity gas along with system operation and configuration allowed the release of 3.38 x 10-6 pCi/cc of Xe' 33 . PIR 84-13.

Iodine Release during Main Coolant Loop #4 Purge - On July 15, 1984 while purging loop 4 the stack charcoal filter did not retain iodine gas as expected. The maximum iodine level offsite for one hour was 29% MPC. PIR 84-14.

Inadvertent Release of LPST Cover Gas via VC Purge System- On May 4, 1987 after degassing the pressurizer, stack monitors detected a gaseous release. A total of 3.5 Ci of radioactive noble gas was released. The valve was repaired. PIR 87-01.

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YNPS Historical Site Assessment Revision 00 , - -

YNPS Historical Site Assessment Revision

. .. ( ld

_r, r

. . t Appendix A2 Summaries of the Significant Events a at the YNPS Site (Presented in HSA Table 7-3) i ., . .. ,- . 1.

, I I :, ,

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YNPS Historical Site Assessment Revision 0-AOR 61-15: Radioactive Spill - 9/20/61 A half-liter container of reactor coolant water was dropped on the asphalt in the Potentially Contaminated Area between the Primary Auxiliary Building and the Waste Disposal Building.

The sample contained approximately 35 ,uCi (specific radionuclide data not available). The spill was absorbed using absorbent paper and the area decontaminated by mopping. The fixed contamination remaining was approximately 0.05 mr/hr at 1 inch from the pavement.

Impacted Areas NOL-02/ NOL-05 AOR 63-12: Shield Tank Cavity Fill Water Spill - 9/18/63 A one-half inch sampling valve located over the IX Pit was inadvertently left open while filling the shield tank cavity. This resulted in a spill of approximately 10 gallons of water from the Safety Injection Tank. A portion of the spill ran off the deck of the pit and onto a section of the blacktop surface to the west of the pit. The radiation level in the immediate area was70-100 mr/hr measured at one inch. Contamination levels were 106 to 107 dpm (specific radionuclide data not available) over areas of several square inches. Run off water resulted in contamination levels of 20-60,000 dpm/ft2 (Sic).

Impacted Areas NOL-01/NOL2 Impacted Structures NSY-02 AOR 63-17: De-watering Pump Packing Leakage - 10/8/63 A water leak from the fuel chute de-watering pump was routed, via a small utility hose, to a 30 gallon collection drum placed in a storm drain catch basin (ECB-005) located between the railroad tracks and the NE corner of the spent fuel pit. It was determined that the bottom rim of the barrel was corroded, and water was leaking from the bottom of the barrel. At the time the leak was identified, six to eight inches of water had accumulated in the barrel with activity of 6 x 10-5 gCi/ml (specific radionuclide data not available). It was believed only a small amount of water was leaked to the storm system.

Impacted Areas OOL-05/0OL-06/NOLl01 Impacted Sub-surface Areas/Structures - East Storm Drain System AOR 64-08: Seal Water Tank Spill - 9/3/64 Shutdown cooling pump seals leaked reactor coolant water and back-flowed into the seal water tank. This caused the tank to overflow through the vent connection, into the common relief valve discharge line and onto the Primary Auxiliary Building roof. An estimated 35 gallons of water containing a total activity of 270 gCi (specific radionuclide data not available) was released. The Roof Drain System drained into the Storm Drain System via a sub-surface piping connection. A sample of the storm drain (WCB-009) was determined to contain I x 10-6 RCi/ml.

The predominant isotopes were Co-58, Co-60 and Mn-54 (distribution of the radionuclides in the sample not available). Service Water was diverted to the storm drain to flush the system.

Impacted Areas - AUX-02 Roof and Roof Drain System Impacted Sub-surface Areas/Structures - West Storm Drain System Page2of6

YNPS Historical Site Assessment Revision 00 YNPS Historical Site Assessment Revision AOR 64-13: Leakage from Ion Exchange Pit - 10/3/64 After filling the Ion Exchange Pit to its normal operating level, the operator failed to close the fill valve. Water continued to flow into the pit from the Primary Water Storage Tank by gravity feed. Later, the operator noticed water seeping through the blacktop on the west side of the pit, diagnosed the cause and closed the valve. The water on the blacktop was sampled and was found to contain radioactivity. The radionuclides and concentrations identified were:' Ag-Il Om at 5 x 10-7 gCi/ml and Co-60 at 1 x 10.6 giCi/ml. The blacktop was rinsed down with Service Water to the storm drain (ECB-005). .I . .

Impacted Areas NSY-02/NOI-,01/OOL-05/OOL-06 Impacted Sub-surfaceAreas/Structures- East Storm Drain System internal and external to piping (backfill) / SFP-02 sub-floor I NSY-09 / AUX-01 North external perimeter (backfill) I SFP-01 West external perimeter (backfill) / BRT-01 Eastern external perimeter..

AOR 66-7: Spent Fuel Pit Water Spill - 9/27/66 A two-inch priming valve for the Spent Fuel Pi (SFP) cooling and purification pump was left open; however an upstream valve isolating make up water to the Low Pressure Surge Tank (LPST) was correctly closed. The LPST make up pump was started to provide make up water to a hose connection located between the two valves to wash down a shipping cask as it was removed from the pit. Water flowed through the open priming valve to the SFP in sufficient quantity to result in actuation of the high level alarm. The reason for the high level alarm was not immediately determined and by the time the reason was identified water had overflowed from the SFP. Approximately 33 gallons of water flowed down the SFP. exterior wall, over a small section of asphalt paving and into an immediately adjacent storm drain, ECB.005. A continuous service water flush of the east side culvert system (ECB-005) was initiated and continued for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. This occurrence resulted in a total release of 4 gCi gross J-y and 670 Ci of...

tritium (more specific radionuclide data not available).

ImpactedAreasSFP-01 North external wall INOIO1/OOL  : .

ImpactedSub-surfaceAreas/StructuresEast Storm Drain System internal and external to piping (backfill between SFP-01 and ECB-005)

AOR 66-8: Abnormal Activity in Storm Drain - 9/27/66 . ,

Water from the west storm drain culvert was sampled (the SFP water released discussed above discharged to the east side only). An average of two samples from the west side showed gross activity of 6.7 x10-7IgCi/ml (specific radionuclide data not available). Investigation found a relief vdlveoon-the safety injection tanklcheating 's'ystem to be slowly leaking into a floor drain in the PAB. -The floor drains in that section bf the building were- traced to discharge to a storm drain located on the outside of the building (WCB-009). -Further investigation indicated that the relief valve leak could not have existed for more' tha one day and that the maximum'volume did not exceed eight gallons'during that period. -A sample of culvert water collected 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the occurrence indicated a gross activity of 1.2 x 10-' [tCi/ml and tritium activity of 5.1 x10-5 giCi/ml. This occurrence resulted in a total release of 0.8 gCi gross P-y and 3.32 mCi tritium.

ImpactedArea - OOL-05/OOL-06 Impacted Sub-surfaceAreas/Structires- West Storm Drain system "

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YNPS Historical Site Assessment Revision Revision 00 YNPS Historical Site Assessment AOR 66-9: Hose Failure - 11/1/66 The hose used for a routine draining of the fuel chute pump discharge line burst. Less than 10 gallons of contaminated water flowed into a storm drain served by the east culvert (ECB-005).

Approximately 10 gallons of water with an activity of 3.0 x 10'3 gCi/ml (for a total of 113 pCi) was released. The spill area was flushed with service water. The east culvert was sampled after the spill.

ImpactedAreas - NOL-01/OOL-01 Impacted Sub-surface Areas/Structures- East Storm Drain system AOR 68-1: Waste Holdup Tank Moat Spill - 1/16/68 The suction line from the waste hold-up tank was found to be frozen. Approximately 200' gallons of water spilled from a valve bonnet failure caused by the freezing of the suction line. A total of 520 gCi f3-y and 698 mCi tritium were spilled into the moat. The spill was contained within the moat structure.

Impacted Structures- NSY-07 PIR 75-7: Yard Area'Contamination 7/16/75 An area of land near the Ion Exchange Pit was identified with a contamination level of approximately 500,000 dpm. Over the next few days, the entire restricted area was surveyed.

Fourteen areas, ten of which were in areas previously identified as a "clean' area," were found to be contaminated at levels greater than 1000 dpm/100 crn 2. Most of the contamination was removed, and the remaining contamination was sealed in place using asphalt sealer and cov'ered with clean soil.

ImpactedAreas - NOL-01 through NOL-06 and SVC-03 Impacted Sub-surfaceAreas/Structures- SVC-03 beneath slab in old RCA access alley PIR 77-16: Service Building Radioactive Sump Transfer Line Puncture- 12/21/77 A boring bit inadvertently punctured the 2.5 inch stainless steel line leading from the Service Building Sump Tanks to the PAB while conducting core borings inside the Radiation Control Area. The sump line ran at a depth of 15 feet underground, where the damage occurred, and the boring depth was 61.5 feet. The damage was not detected until the next day when the sump pump started and water issued from ihe borehole. The sump pump ran through two cyclesl resulting in 20 gallons of water discharged from the rupture. The water contained the foll&wing:

Radionuclide Total Activity, gCi lConcentration, Cimll Fraction of MPC 1-131 16.50 2.18 x 10 3.63 I-133 2.76 3.65 x 10-5 0.18 Cs-134 0.34 4.46 x 10" 0.01 Cs-137 0.50' 6.67 x 10' 0.02 Co-60 0.58 7.69 x 10-" 0.01 No measurable levels of activity were released offsite or to the storm drain. The line was repaired, and a sand and concrete casing was poured around it.

ImpactedAreas - NOL-02 Impacted Sub-surface Areas/Structures- Soils surrounding perforation and transfer line backfill/Soils to a depth of 61.5 feet and below along the bore hole.

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YNPS Historical Site Assessment YNPSHisorial Ste ssesmen Revision 0 .

Reisin 0 PIR 80-9: Resin Spill - 8/6/80 K. A hose developed a pinhole leak, while pumping resin to a cask. The failure of the hose allowed the release of several gallons of water and one quart of resin. A 15 foot by 20 foot area of the RCA yard was contaminated. Radiation readings on contact with the resin were 1 mrad/hr and the spilled liquid reading were up to several hundred thousand dpm/l 00 .cn1 (sic) (specific radionuclide data not available). Decontamination included removal and disposal of some of the blacktop.

ImpactedAreas- NOL-02/NSY-02 ImpactedSub-surfaceAreas/Structures - South and East exterior walls of NSY-02. The sub-slab area of NSY-02 (IX-pit) was also impacted due to transfer of contamination by surface water (i.e., water used in decontamination and rainwater) into cracks between asphalt and IX Pit walls.

PIR 81-9: Contamination of Yard Area During Reactor Head Removal - 5/15/81 While positioning the reactor vessel head over the equipment hatch in preparation to lower the head through the equipment hatch, the reactor head made contact with the shield wall. This resulted in the spread of removable radioactivity outside of the Vapor Container (VC).

Removable radioactivity immediately below the equipment hatch was 200 mrad/hr beta. The total activity released to the ground was approximately 250 gCi, with approximately I0 pCi (specific radionuclide data not available) discharged to Sherman Pond. The area was cleaned, but due to rainfall trace radioactive material levels were detected in the east storm drains.

ImpactedAreas- NOL-01/NOL-0610OL-12100L-13 ImpactedSub-surface Areas/Structures - BRT-01/in cracks and crevices under VC

'; \Equipment Hatch and along rails/ties in OOL-12 and OOL-13 and the East Storm Drain System due to surface water run-off.

PIR 84-16: Drain Pipe Failure - 9/10/84 An excavated drainpipe from the Potentially Contaminated Area (PCA) storage building to the Waste Disposal building was found to be leaking. Soil samples from around the pipe identified the presence of Co-60 and Cs- 137 and the excavation of the pipe continued. The area of maximum contamination was measured at 25-35 mR/hr (specific radionuclide data not available), with a hot spot of 29,300 pCi/gm Co-60 in this same area. The pipe from the edge of the old PCA (Potentially Contaminated Area) building to the edge of the waste disposal building and approximately 420 ft3 of dirt and rock were removed as radioactive waste. The soil remaining at the bottom of the excavation contained Co-60 at an average concentration of 30 pCi/gm.

ImpactedAreas - WST-01/WST-02/WST-03 ImpactedSub-surfaceAreas/Structures- WST-02 at a depth in excess of 9 feet below grade, activity remains potentially in excess of the soil DCGL. WST-03 at ash dewatering sump in drumming pit. Decommissioning standards had not yet been developed at the time this partial remediation was performed. Radiological decay since 1984 may have reduced the radionuclide concentration below the soil DCGL. Further scoping data will be collected below the 9 foot clean backfill to confirm this evaluated condition.

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YNPS Historical Site Assessment Revision O.

PIR 94-03 & 94-09.

Leakage from Frozen Fuel Chute Dewatering Line and NST Tell-tales On February 17 and 18, 1994, a fuel chute dewatering line and a neutron shield tank telltale drain line ruptured due to freezing. A 3.5 liter sample from the fuel' chute line indicated 1000 net cpm, and a sample from the NST telltale line indicated the presence of Co-60 and Cs-137. The ground' below the rupture, as well as the area adjacent to the railroad tracks and pumpback house,'

showed no contamination. However, the snow pile along the south side of the rails by the new fuel vault indicated the presence of Co-60, Cs-137 and Mn-54. All snow piles with positive radiation measurements were sent to the rad drains and the areas de-posted.

ImpactedArea - NOL-01 Page 6 of 6