ML052140116

Final Status Survey Report for Saxton Nuclear Experimental Corporation Saxton Steam Generating Station Structural Surfaces - Cv Steam Tunnel SS22, Main Report

ML052140116
Person / Time
Site:	Saxton File:GPU Nuclear icon.png
Issue date:	07/31/2005
From:	GPU Nuclear
To:	Office of Nuclear Reactor Regulation
References
Download: ML052140116 (20)

Text

Final Status Survey Report For Saxton Nuclear Experimental Corporation Saxton Steam Generating Station Structural Surfaces - CV Steam Tunnel SS22 m ,, rn - 239 9 3131 " 31 mu_ '!¶!L!L-'-'h ii 93 13 II - ALA

-mm I

"' I --1

. 'n B

- qt -e,, ,,' ' . '. , _

Prepared by GPU Nuclear, Inc.

July 2005

Table Of Contents Executive Summary

1.0 Purpose and Scope

2.0 Survey Area Description 3.0 Operating History 3.1 Plant Operations 3.2 Survey Area Remediation Status 4.0 Site Release Criteria 5.0 Final Status Survey Design / DQO Process 6.0 Final Status Survey Results 6.1 Summary for Survey Unit SS22-1 6.2 Summary for Survey Unit SS22-2 6.3 Summary for Survey Unit SS22-3 6.4 Summary for Survey Unit SS22-5 7.0 Data Assessment 7.1 Assessment Criteria 7.2 Summary of Overall Results 7.3 Survey Variations 7.4 Quality Control Measurements 8.0 Final Survey Conclusions 9.0 References 10.0 Appendices i

Executive Summary This report presents the results and conclusions of the final status survey (FSS) of the Class 1 structural surfaces of the Saxton Nuclear Experimental Corporation (SNEC) facility designated as SS22. This FSS includes surveys of residual structural surfaces (e.g. concrete and steel) in the Containment Vessel (CV)Steam Tunnel of the SNEC site and was conducted in the summer of 2004.

The FSS was performed in accordance with the SNEC License Termination Plan (LTP). The CV Steam Tunnel survey area was divided into four survey units.

Three units consisted of relatively flat residual structural surfaces but did contain some uneven concrete and steel. The fourth survey unit consisted of remaining embedded unistrut. Data was collected from each survey unit in accordance with the specific survey design data collection requirements. The following is a summary of the measurements performed:

1) Gas Flow Proportional Counter (GFPC) scans of concrete and steel surfaces

2) Nal scans of concrete and steel surfaces

3) Thirty nine GFPC static measurements

4) Eighty-one Nal static measurements

5) Sixty five smear samples The collected FSS survey data demonstrate that the 91 square meters of the CV Steam Tunnel survey area meets the radiological release criteria for unrestricted use specified in 10CFR20.1402. Therefore GPU Nuclear, Inc. concludes that the area meets the NRC requirements and may be released for unrestricted use.

1 of 18

1.0 Purpose and Scope

This report presents the results and conclusions of the final status survey of the residual structural surfaces in the CV Steam Tunnel west of the SNEC facility.

The survey area consists of three mostly concrete surface survey units designated SS22-1, SS22-2, and SS22-3 and one unit designated SS22-5 consisting of residual unistrut. Designation SS22-4 is not used. This report provides the information required by 10CFR50.82(a)(11) and the SNEC license termination plan (LTP) to demonstrate that this area meets the radiological criteria for unrestricted use specified in IOCFR20.1402.

This report describes the radiological data collected in four Class 1 survey units of residual structural surface in the CV Steam Tunnel. This report only addresses the FSS performed on this specific area. The format of this report follows the guidance contained in reference 9.2.

2.0 Survey Area Description The CV Steam Tunnel is Class 1 impacted structural surface located below grade to the west of the SNEC facility. The survey area encompasses about 91 square meters of concrete and steel including 6 square meters from about 70 linear feet of unistrut. Because there are three distinct regions in the chambers plus the residual unistrut, the survey area has been divided into four survey units.

The four survey units are discussed below. The individual survey unit designations are derived from table 5-2 of the SNEC LTP (reference 9.3).

Survey unit SS22-1 is a Class 1 residual concrete and steel surface in the remaining portion of the CV Steam Tunnel between the CV and the Saxton Steam Generating Station (SSGS). It consists of the floor of the CV Steam Tunnel - an underground room between the SSGS and the CV. The survey unit is approximately 21 square meters.

Survey unit SS22-2 is a Class 1 residual concrete and steel surface in the remaining portion of the CV Steam Tunnel between the CV and the SSGS. It consists of the walls of the CV Steam Tunnel - an underground room between the SSGS and the CV. The survey unit is approximately 48 square meters.

Survey unit SS22-3 is a Class 1 residual concrete and steel surface in the remaining portion of the CV Steam Tunnel between the CV and the SSGS. It consists of the ceiling of the CV Steam Tunnel - an underground room between the SSGS and the CV. The survey unit is approximately 16 square meters.

Survey unit SS22-5 is a Class I residual steel surface in the remaining portion of the CV Steam Tunnel between the CV and the SSGS. It consists of the residual 2 of 18

unistrut of the CV Steam Tunnel - an underground room between the SSGS and the CV. Because of the unique nature of the unistrut, the survey unit is primarily discussed in linear feet of unistrut instead of square meters. The survey unit is approximately 70 linear feet of unistrut and totals about 6 square meters.

3.0 Operating History 3.1 Plant Operation The Saxton Nuclear Experimental Corporation (SNEC) facility included a pressurized water reactor (PWR), which was licensed to operate at 23.5 megawatts thermal (23.5 MWTh). The reactor, containment vessel and support buildings have all been removed. The facility is owned by the Saxton Nuclear Experimental Corporation and is licensed by GPU Nuclear, Inc. The SNEC facility is maintained under a Title 10 Part 50 license and associated Technical Specifications. In 1972, the license was amended to possess but not operate the SNEC reactor.

The facility was built from 1960 to 1962 and operated from 1962 to 1972 primarily as a research and training reactor. Steam from the SNEC reactor was directed to the adjacent Saxton Steam Generating Station (SSGS), through piping in the CV Steam Tunnel, to generate electricity. Other shared systems also introduced SNEC activity into the SSGS and the main SNEC discharge entered the SSGS discharge tunnel. After shutdown in 1972, the SNEC facility was placed in a condition equivalent to the current SAFSTOR status. Since then, it has been maintained in a monitored condition. The fuel was removed in 1972 and shipped to a (now DOE) facility at Savannah River, SC, who is now the owner of the fuel.

As a result of this, neither SNEC nor GPU Nuclear, Inc. has any further responsibility for the spent fuel from the SNEC facility. The building and structures that supported reactor operation were partially decontaminated by 1974. The SSGS was dismantled circa 1974.

In the late 1980s and through the 1990s, additional decontamination and disassembly of the containment vessel and support buildings and final equipment and large component removal was completed. Final decontamination and dismantlement of the reactor support structures and buildings was completed in 1992. Large component structures, pressurizer, steam generator, and reactor vessel were removed in late 1998. Containment vessel removal (to below grade) and backfill was completed in late 2003. Currently, decontamination, disassembly and demolition of the SNEC facility buildings and equipment has been completed and the facility is in the process of Final Status Survey for unrestricted release and license termination.

3.2 Survey Area Remediation Status 3 of 18

The CV Steam Tunnel had potential for contamination as a result of radioactive liquid and steam systems that were present in the tunnel. Piping systems were removed circa 1974. Remediation included removal of piping and concrete surfaces. A large portion of the tunnel was completely removed, leaving a portion about 36 feet long. Remediation was performed on this remaining portion to reduce the residual volumetric contamination. Following survey, the remaining portion of the tunnel was collapsed into itself.

4.0 Site Release Criteria The site release criteria applied to the structural surface areas of the CV Steam Ttunnel correspond to the radiological dose criteria for unrestricted use per IOCFR20.1402. The dose criteria is met 'if the residual radioactivity that is distinguishable from background radiation results in a Total Effective Dose Equivalent (TEDE) to an average member of the critical group that does not exceed 25 mrem/yr, including that from groundwater sources of drinking water, and that the residual radioactivity has been reduced to levels that are as low as reasonably achievable (ALARA)".

Levels of residual radioactivity that correspond to the allowable dose to meet the site or survey unit release criteria for structural surfaces were derived by analyses using a building re-use scenario. The dose modeling for this scenario is explained in the SNEC LTP (reference 9.3). The derived concentration guideline levels (DCGL) shown in Table 5-1 of the SNEC LTP form the basis for satisfying the site release criteria.

Residual radioactivity sample results for the surfaces were used to calculate a surrogate Cs137 DCGL. The adjusted surrogate DCGL was developed using the methodology described in the SNEC LTP section 5.2.3.2.3 based on nuclide specific DCGLs from Table 5-1 of the LTP.

An adjustment was made to the surrogate Cs137 DCGL to address the de-listed radionuclides as described in the LTP section 6.2.2.3. SNEC has instituted an administrative limit of 75% of the DCGL for all measurement results. The de-listed radionuclides are conservatively accounted for in this 25% reduction since the de-listed radionuclides were only 4.7% of the dose contribution. These adjustment factors are discussed in section 6 of the SNEC LTP.

5.0 Final Status Survey Design and DQO The SNEC calculations providing the design of the survey for these survey units is provided in Appendices A and B. Scan coverage of the three Class 1 concrete survey units covered approximately 100% of the available surfaces. Scans were conducted using Gas Flow Proportional Counters (GFPC) and 2 inch by 2 inch Nal detectors. The unistrut was surveyed by static measurements with 100%

4 of 18

coverage. The SNEC calculation providing an assessment of the results of the unistrut measurements is attached in Appendix C.

Fixed point measurements were performed with the GFPC in the three concrete survey units and with Nal detectors on the unistrut.

The survey designs use a surrogate Cs137/gross beta effective DCGL developed from radionuclide mix analyses from samples collected before the Final Status Survey in the vicinity of the survey unit. The mix was based on radionuclide mix data (including the hard-to-detects listed in Table 5-1 of the LTP) from the CV, CV Tunnel, and SSGS mezzanine (attachment 3 of appendix A).

Cs137, Co6Q, and Sr90 were positively detected in one or more of these samples and are accounted for in the adjusted surrogate DCGL. The following table (Table 5.0-1) presents the Data Quality Objectives (DQO) and other relevant information from the survey design package.

5 of 18

Table 5.0 DQO/D sign DQO/Design Parameter* SS22-1, SS22-1, SS22-3 SS22-5 SNEC Design Caic. # E900-03-019 E900-04-012 E900-04-004 MARSSIM Classification I 1 Survey Unit Area (m2 ) 21,48,16 6 M2 , 70 linear feet Statistical Test WRS WRS Type 1 decision error (a) 0.05 0.05 Type 2 decision error () 0.10 0.10 LBGR (cpm) 1925 N/A*

Estimated a (cpm) 51 N/A Relative Shift (A/a) 3.0 N/A Number of static points'* 15,11,13 81 DCGLw (Cs137 27250 27250 dpm/100cm2 )

75% Admin Limit (Cs137 20438 20438 2

dpm/lOOcm )

75%Admin limit -static 2077 N/A (Cs137 cpm)

DCGLw (Cs137 pCi/g) 6.32 6.32 75%Admin Limit -scan 1100 (gross GFPC) N/A (cpm) 300 (gross Nal) 75% Admin Limit (pCi/gm) 4.74 4.74 Scan MDC (dpm/100cm 2 ) 5838 (Nal), 1653 (GFPC) NIA*'*

Static MDC(dpm/JOOcm 2 ) N/A 2215 SNEC Survey Request# SR144 SR115 Scan Survey Instrument GFPC, Nal Nal

• Since the unistrut was 100% static measured, no statistical sampling parameters were required Number of static points actually performed

• no Nal scans were performed under calculation 04-004.

6.0 Final Status Survey Results The following sections provide the survey summary results for each survey unit as required by the respective design. Summary data was taken from references 9.8 and 9.9 which are filed in the SNEC history files.

6.1 Survey Unit SS22-1 6 of 18

6.1.1 Scan survey Scan measurements were made in SS22-1 using the GFPC with follow-up using the Nal detector. The GFPC had an MDCscan of 1653 dpm/1OOcm 2 (attachment 8.4 of appendix A). The adjusted surrogate Cs137 beta DCGLw for this survey unit was 27250 dpm/1OOcm 2 and the 75% administrative limit was 20438 dpm/1OOcm 2 (Attachment 3-5 of appendix A).

Of the approximately 21 square meters of this survey unit, portions were inaccessible for GFPC scanning for various reasons, particularly a small area of steel plate. Of the 21 square meters, all were scanned, except for about 0.4 square meters that was inaccessible. About 20 square meters out of 21 were scanned with both the GFPC and with the Nal. Therefore about 95 percent of the survey unit was scanned and 100% of the accessible area.

All GFPC scan surveys indicated activity less than the action level of 1100 gross cpm. All Nal scan surveys indicated less than the action level of 300 gross cpm.

6.1.2 Fixed point measurements Fifteen random start systematic fixed point measurement locations were defined for the survey unit. Based on a conservative relative shift of about 3.0 a minimum of 8 fixed points were required.

None of the design fixed point measurements in SS22-1 had results in excess of the of 75% administrative limit of 2077 net cpm for the GFPC measurements.

The table below (Table 6.1-1) shows the gross beta results for each fixed point measurement, along with the mean, standard deviation and range of the fixed point measurement data.

Smears collected at the fixed point locations were all less than the MDC at <166 dpm/1OOcm 2 for beta and <12.3 dpm/1OOcm 2 for alpha.

The standard deviation of the GFPC measurements collected from the survey unit was less than the variability assumed in the survey design. Therefore, the assessment of variability, relative shift, and number of fixed point measurements required is consistent between the survey design and the survey results. Based on this, no changes to the survey design or additional measurements are required.

7 of 18

Table 6.1 Fixed point results for SS22-1 Point GFPC Number Unshielded cpm 1 . 320 2 352 3 352 4 374 5 359 6 378 7 293 8 350 9 341 10 365 11 326 12 351 =

13 344 14 318 15 339 Mean 344 Std Dev 22.6 Min 293 Max 378 6.2 Survey Unit SS22-2 6.2.1 Scan survey Scan measurements were made in SS22-2 using the GFPC with follow-up using the Nal detector. The GFPC had an MDCscan of 1653 dpm/1OOcm 2 (attachment 8.4 of appendix A). The adjusted surrogate Cs137 beta DCGLw for this survey unit was 27250 dpm/1 OOcm 2 and the 75% administrative limit was 20438 dpm/l100cm 2 (Attachment 3-5 of appendix A).

Of the approximately 48 square meters of this survey unit, portions were inaccessible for GFPC scanning because of wood posts holding the roof in place.

Of the 48 square meters, all were scanned, except for about 1 square meter that was inaccessible. About 47 square meters out of 48 were scanned with both the GFPC and with the Nal. Therefore about 98 percent of the survey unit was scanned and 100% of the accessible area.

All GFPC scan surveys indicated activity less than the action level of 1100 gross cpm. All Nal scan surveys indicated less than the action level of 300 gross cpm.

6.2.2 Fixed point measurements 8 of 18

Eleven random start systematic fixed point measurement locations were defined for the survey unit. Based on a conservative relative shift of about 3.0 a minimum of 8 fixed points were required.

None of the design fixed point measurements in SS22-2 had results in excess of the of 75% administrative limit of 2077 net cpm for the GFPC measurements.

The table below (Table 6.2-1) shows the gross beta results for each fixed point measurement, along with the mean, standard deviation and range of the fixed point measurement data.

Smears collected at the fixed point locations were all less than the MDC at <169 dpm/1 OOcm 2 for beta and <112 dpm/1 OOcm 2 for alpha.

The standard deviation of the GFPC measurements collected from the survey unit was slightly larger than the variability assumed in the survey design.

However, the LBGR used was conservative and was much higher than the typical 50% of the DCGL recommended. The observed variability combined with a slightly reduced LBGR would still result in a relative shift of 3. Therefore, the assessment of variability, relative shift, and number of fixed point measurements required is consistent between the survey design and the survey results. Based on this, no changes to the survey design or additional measurements are required.

Table 6.2 Fixed point results for SS22-2 Point GFPC Number Unshielded cpm 1 274 2 321 3 318 4 362 5 363 6 214 7 329 8 393 9 362 10 408 11 349 Mean 336 Std Dev 54.8 Min 214 Max 408 6.3 Survey Unit SS22-3 6.3.1 Scan survey 9 of 18

Scan measurements were made in SS22-3 using the GFPC with follow-up using the Nal detector. The GFPC had an MDCscan of 1653 dpm/IOOcm 2 (attachment 8.4 of appendix A). The adjusted surrogate Cs137 beta DCGLw for this survey unit was 27250 dpm/1 00cm2 and the 75% administrative limit was 20438 dpm/1 00cm2 (Attachment 3-5 of appendix A).

Of the approximately 16 square meters of this survey unit, portions were inaccessible for GFPC scanning because of the configuration of the end portion of the roof. Of the 16 square meters, all were scanned, except for about 1.9 square meters that was inaccessible. About 14 square meters out of 16 were scanned with both the GFPC and with the Nal. Therefore about 88 percent of the survey unit was scanned and 100% of the accessible area.

All GFPC scan surveys indicated activity less than the action level of 1100 gross cpm. All Nal scan surveys indicated less than the action level of 300 gross cpm.

6.3.2 Fixed point measurements Thirteen random start systematic fixed point measurement locations were defined for the survey unit. Based on a conservative relative shift of about 3.0 a minimum of 8 fixed points were required.

None of the design fixed point measurements in SS22-3 had results in excess of the of 75% administrative limit of 2077 net cpm for the GFPC measurements.

The table below (Table 6.3-1) shows the gross beta results for each fixed point measurement, along with the mean, standard deviation and range of the fixed point measurement data.

Smears collected at the fixed point locations were all less than the MDC at <166 dpm/1OOcm 2 for beta and <12.3 dpm/100cM 2 for alpha.

The standard deviation of the GFPC measurements collected from the survey unit was less than the variability assumed in the survey design. Therefore, the assessment of variability, relative shift, and number of fixed point measurements required is consistent between the survey design and the survey results. Based on this, no changes to the survey design or additional measurements are required.

10 of 18

Table 6.3 Fixed point results for SS22-3 Point GFPC Number Unshielded cpm 1 381 2 349 3 353 4 372 5 390 6 412 7 411 8 362 9 394 10 388 11 404 12 425 13 440 Mean 391 Std Dev 27.5 Min 349 Max 440 6.4 Survey Unit SS22-5 6.4.1 Scan survey Survey unit SS22-5 consisted only of the 70 linear feet of unistrut. The unistrut received a static measurement every foot. Therefore, static measurements were performed on 100% of the unistrut in lieu of scanning.

6.4.2 Fixed point measurements Eighty one fixed point measurement locations were defined for the survey unit, one every foot along the unistrut. The design basis for the conversion factors for the detector was based on a one foot long source area. Therefore, the unistrut received 100% static measurements.

There was no specific action level defined in the survey design for the unistrut, so the results were specifically assessed (appendix C). The table below (Table 6.4-

1) shows the Nal results for each fixed point measurement, along with the mean, standard deviation and range of the fixed point measurement data. Attachment 5 of appendix C shows that the maximum static measurement was about 38% of the 75% administrative limit for surface contamination.

Twenty six smears collected on the unistrut were all less than the MDC at <169 dpm/1 OOcm 2 for beta and <11 dpm/1 00cm2 for alpha.

11 of 18

Table 6.4 Fixed point Nal results for SS22-5 Point GFPC Number Unshielded cpm 1 120 2 103 3 106 4 107 5 125 6 125 7 108 8 116 9 127 10 117 11 139 12 126 13 118 14 119 15 135 16 134 17 116 18 119 19 114 20 139 21 122 22 118 23 110 24 119 25 126 26 105 27 110 28 150 29 132 30 135 31 130 32 157 33 127 34 135 35 130 36 121 37 143 38 153 39 136 40 142 41 130 42 136 43 155 44 129 12 of 18

Table 6.4-1 (continued) - Fixed point Nal results for SS22-5 45 129 46 148 47 147 48 142 49 151 50 135 51 136 52 172 53 157 54 166 55 141 56 150 57 171 58 150 59 147 60 131 61 126 62 117 63 122 64 139 65 146 66 143 67 152 68 97 69 106 70 110 71 98 72 115 73 97 74 97 75 102 76 128 77 115 78 121 79 120 80 98 81 93 Mean 128 Std Dev 18.2 Min 93 Max 172 7.0 Data Assessment 7.1 Assessment Criteria 13 of 18

The final status survey data has been reviewed to verify authenticity, appropriate documentation, quality, and technical acceptability. The review criteria for data acceptability are:

1) The instruments used to collect the data were capable of detecting the radiation of the radionuclide of interest at or below the investigation levels.

2) The calibration of the instruments used to collect the data was current and radioactive sources used for calibration were traceable to recognized standards or calibration organizations.

3) Instrument response was checked before and, when required, after instrument use each day data was collected.

4) Survey team personnel were properly trained in the applicable survey techniques and training was documented.

5) The MDCs and the assumptions used to develop them were appropriate for the instruments and the survey methods used to collect the data.

6) The survey methods used to collect the data were appropriate for the media and types of radiation being measured.

7) Special instrument methods used to collect data were applied as warranted by survey conditions, and were documented in accordance with an approved site Survey Request procedure.

8) The custody of samples that were sent for off-site analysis were tracked from the point of collection until final results were provided.

9) The final status survey data consists of qualified measurement results representative of current facility status and were collected in accordance with the applicable survey design package.

If a discrepancy existed where one or more criteria were not met, the discrepancy was reviewed and corrective action taken (as appropriate) in accordance with site procedures.

The statistical test does not need to be performed for this final status survey since the data clearly show that the survey unit meets the release criteria because all measurements in the survey units are less than or equal to the DCGLw.

14 of 18

7.2 Summary of Overall Results SS22-1 had no alarm points during scan surveys of approximately 100% of the accessible surface. Scan MDCs were adequate. GFPC fixed point measurements were all less than the action level. Scan fraction and number of fixed point measurements meets LTP and MARSSIM requirements.

SS22-2 had no alarm points during scan surveys of approximately 100% of the accessible surface. Scan MDCs were adequate. GFPC fixed point measurements were all less than the action level. Scan fraction and number of fixed point measurements meets LTP and MARSSIM requirements.

SS22-3 had no alarm points during scan surveys of approximately 100% of the accessible surface. Scan MDCs were adequate. GFPC fixed point measurements were all less than the action level. Scan fraction and number of fixed point measurements meets LTP and MARSSIM requirements.

SS22-5 was surveyed using almost 100% static measurement coverage of the accessible surface. An assessment of the results shows that all measurements were below the 75% administrative limit. No scan surveys were performed because 100 percent static measurement eliminates the need for scanning.

7.3 Survey Variations (Design, survey request, LTP) 7.3.1 Approximately 0.4 square meters of SS22-1 could not be scan surveyed due to interferences.

7.3.2 Approximately 1 square meter of SS22-2 could not be scan surveyed due to interferences.

7.3.3 Approximately 1.9 square meters of SS22-3 could not be scan surveyed due to interferences.

7.3.4 Static point SS22-1 #15 was relocated 2 inches due to surface configuration 7.3.5 Static point SS22-3 #7 was relocate 20 inches due to interferences.

7.4 QC comparisons 7.4.1 Scan surveys Numerous areas were rescanned as QC duplicates. The QC rescans did not identify any activity above alarm points and therefore are in agreement with the primary scans because they both support the same conclusion, that the survey 15 of 18

unit passes. GFPC QC scans were conducted on 6 m2 of the survey area, which represents about 7.4 percent of the 81 m2 originally scanned with the GFPC. This exceeds the minimum 5% required. Nal QC scans were also conducted on 6 m2 of the survey area, which also represents about 7.4 percent of the 81 m2 originally scanned with the Nal. This exceeds the minimum 5% required.

7.4.2 Fixed Point measurements Several fixed point measurements were duplicated for QC purposes. The QC fixed point measurements did not identify any activity above alarm points and therefore are in agreement with the primary result because they both support the same conclusion, that the survey unit passes. GFPC QC fixed point measurements were performed on 3 locations, which represent 7.7 percent of the 39 primary measurements. Table 7.4-1 below shows the GFPC comparison.

Nal QC fixed point measurements were performed on 5 locations, which represent 6.2 percent of the 81 primary measurements. Table 7.4-2 below shows the Nal comparison. These exceed the minimum 5% required.

Table 7.4 Fixed point GFPC QC Point Initial QC Number result cpm result cpm SS22-1 10 365 362 SS22-2 4 362 385 SS22-3 10 388 414 Table 7.4 Fixed point Nal QC Point Initial QC Number result cpm result cpm SS22-5 14 119 114 SS22-5 35 130 132 SS22-5 50 135 108 SS22-5 74 97 110 SS22-5 81 93 79 8.0 Final SurveV Conclusions The Structural Surfaces of the CV Steam Tunnel survey units SS22-1, SS22-2, SS22-3, and SS22-5 final status survey was performed in accordance with the SNEC LTP, site procedures, design calculations, and Survey Request requirements. FSS data was collected to meet and/or exceed the quantity specified or required for each survey unit design. The survey data for each survey unit meets the following conditions:

16 of 18

1) The average residual radioactivity on the surfaces is less than the derived surrogate DCGLw in all of the survey units.

2) All measurements were less than the DCGLw in all four survey units.

3) A special assessment of residual volumetric activity in the unistrut demonstrates that residual radioactivity is less than 38% of the 75%

administrative limit.

These conditions satisfy the release criteria established in the SNEC LTP and the radiological criteria for unrestricted use given in IOCFR20.1402.

Therefore it is concluded that the SNEC Structural Surface Areas of the CV Steam Tunnel designated SS22 are suitable for unrestricted release.

17 of 18

9.0 References 9.1 SNEC Facility Site area grid map Drawing number SNECRM-020 9.2 SNEC procedure E900-ADM-4500.60 "Final Status Survey Report" 9.3 SNEC License Termination Plan 9.4 NUREG 1575 'Multi-Agency Radiation Survey and Site Investigation Manual" (MARSSIM), revision 1 August 2000 9.5 COMPASS computer program, Version 1.0.0, Oak Ridge Institute for Science and Education 9.6 SNEC procedure E900-IMP-4500.59, 'Final Site Survey Planning and DOQA" 9.7 SNEC procedure E900-IMP-4520.04, 'Survey Methodology to Support SNEC License Termination" 9.8 SNEC Survey Request (SR) # SR115 9.9 SNEC Survey Request (SR) # SR144 10.0 Appendices Appendix A - SNEC Calculation E900-04-012 - "CV Tunnel & Top of Seal Chambers 1&2 Survey Design" (10 pages plus numerous attachments)

Appendix B - SNEC Calculation E900-04-004 - "CV Tunnel Unistrut Survey Design" (9 pages plus numerous attachments)

Appendix C - SNEC Calculation E900-05-029 - "Assessment of CV Tunnel Unistrut" (4 pages plus numerous attachments) 18 of 18