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TSD-10-002, Revision 0, Technical Basis for Radiological Limits for Structure/Building Open Air Demolition
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TSD # 10-002 Revision 00 Page 2 of 20 Technical Basis for Radiological Limits for Structure/Building Open Air Demolition 1.0 Executive Summary 2.0 Introduction This Technical Support Document (TSD) provides the basis for the Open Air demolition Radiological Control Indicators that are applied to buildings and structures for demolition.

These indicators are designations used to characterize the acceptable removable contamination and contact deep dose equivalent radiation levels that are allowable for open air demolition.

3.0 Table of Contents 1.0 Executive Summary ....................................................................................................................... 2 2.0 Introduction.................................................................................................................................... 2 3.0 Table of Contents ........................................................................................................................... 2 4.0 Background .................................................................................................................................... 2 4.1 Off-Site Dose Impact Method ....................................................................................................... 2 Table 2 - Summary of Offsite Dose Evaluations ...................................................................................... 3 4.2 Radiological Objectives for Open Air Demolition ........................................................................ 3 4.3 Radiological Control Indicator Method ......................................................................................... 4 5.0 Calculations or Evaluations ........................................................................................................... 5 5.1 Summary of Connecticut Yankee Removable Contamination Limit Evaluation .......................... 5 5.2 Summary of Connecticut Yankee Concrete Demolition Test Results........................................... 6 6.0 Conclusions.................................................................................................................................. 19 Table 20 - Recommended Open Air Demolition Limits........................................................................ 19 7.0 Attachments ................................................................................................................................. 20 7.1 None ............................................................................................................................................. 20 8.0 References.................................................................................................................................... 20 4.0 Background 4.1 Off-Site Dose Impact Method Several decommission facilities established open air demolition criteria based upon the offsite dose impact of the activity from airborne effluents. The documents provided as references 1 through 3 used a conventional industry approach for safety related bounding calculation to establish limits for open demolition. This approach calculates the acceptable levels of fixed and removable contamination based upon re-suspension factors and ground level release and dispersion models. The limits are based upon the calculated member of the public dose at the site boundary using Off Site Dose Calculation Manual (ODCM) methodologies for a ground level airborne radioactivity release.

TSD # 10-002 Revision 00 Page 3 of 20 As shown in Table 2 this approach results in relatively high levels of contamination being acceptable for open air demolition with minor off-site dose consequences.

Table 1 - Summary of Offsite Dose Evaluations Removable Contamination Offsite Dose Facility Level Total Contam Level (mrem) Control Criteria Summary 2

> 25,000 dpm/100 cm removable 2

of 250,000 dpm/100 cm total requires contamination control measure (e.g., fixative, local ventilation, enclosures)

Air samples not to exceed 0.05 DAC beta/gamma or >MDA alpha.

1.7E-3 Personnel contamination controls 2

instantaneous below 25,000 dpm/100 cm 2

SONGS Unit 1 N/A 1.5E+6 dpm/100 cm release required.

6.66E-2 entire decommissioni ng based upon estimated Could result in up to 4600 dpm/100 2

surface area of cm deposition within 50 feet of buildings and demolition with 10% plate out. May 2 2 5000 dpm/100 cm 500,000 dpm/100 cm average require layer of soil to be removed beta/gamma 20 beta/gamma 100 contamination for FSS. Will have to be managed 2 2 Maine Yankee dpm/100 cm alpha dpm/100 cm alpha levels for equipment release.

Maintain work zone air concentrations less than 0.25 DAC to maintain member of public dose Average < 5000 2E-3 mrem/yr below 0.2 mrem/yr No other limits 2

Yankee Rowe dpm/100 cm max organ specified.

Similar offsite dose evaluations of airborne radioactivity ground releases were performed at Connecticut Yankee as documented in reference 4. This Technical Support Document evaluated the offsite dose consequences of an instantaneous release of a 2000 DAC Am-241 source term due to a HEPA filter failure. The calculated member of the public dose at the unrestricted area boundary was 1.77 mrem for a release of this magnitude. Similarly the airborne effluent bounding calculation in XX of the Zion DSAR shows that a fire in 1000 Ci Co-60 resin high integrity container (HIC) would result in 989 mrem at the site boundary. Using similar resuspension factors, a 1 Ci source term would result in less than 1 mrem to a member of the public at the site boundary. Thus, demolition and sizing of contaminated structures and materials can be performed without significantly increasing the radiation exposure of members of the public at the owner controlled area boundary.

4.2 Radiological Objectives for Open Air Demolition Other objectives, in addition to the member of the public dose at the site boundary, should be considered when establishing Radiological Control Indicators for open air demolition. Liquid effluents should also be considered when establishing these criteria. During demolition liquids enter the contaminated construction debris from dust suppression spray, precipitation, and, for sub-surface structures, by groundwater intrusion. Demolition liquids must be controlled in accordance with National Pollutant Discharge Elimination System (NPDES), Storm Water Pollution Prevention Plans

TSD # 10-002 Revision 00 Page 4 of 20 (SWPP), and ODCM .to ensure run-off from above ground activities and groundwater intrusion is collected, processed, monitored and released using plant water processing systems and discharge points.

The off-site dose based approach does not address additional considerations such as:

Allowing open air demolition without instituting Contaminated Area controls such as, posting, clearance, and protective clothing controls in outside areas.

Impact of the liberated source term on soil concentrations required for License Termination.

Ensuring radioactivity concentrations in high conductivity, high pH demolition water remain low enough to release without use of demineralizers. Groundwater intrusion during demolition at Connecticut Yankee required large quantities of water to be processed and released as part of the demolition process due to groundwater intrusion.

Given these the objectives of the open air demolition limits are the following:

Ensure ground level airborne radioactivity levels and off-site dose consequences remain ALARA and within regulatory limits.

Ensure demolition liquid concentrations remain at levels which can be collected, processed and released using plant water treatment systems and discharge points.

Minimize the spread on contamination within the site boundary such that there is not significant effect on groundwater or the scope of soil remediation required for License Termination.

Ensure open air demolition activities can be conducted using conventional demolition techniques with minimal radiological restrictions or controls (e.g., without area, equipment or personnel contamination controls).

4.3 Radiological Control Indicator Method Radiological Control Indicators (RCI) were developed at Connecticut Yankee as part of the request for proposals and contract agreements with the Decommissioning Operation Contractor (DOC). The RCIs provided the contractual basis for radiologically acceptable levels for various phases and types of structure demolition. These indicators were used to clearly specify contractual requirements for the demolition of buildings with regards to acceptable levels of fixed and removable contamination. The levels were defined as the following:

R1 was designated to structures where the radiological contamination is indistinguishable from background. This designation is only applied to structures that reside outside any Radiologically Controlled Area (RCA) of the facility. Prior to Release of a structure for R1 demolition, an Unconditional Release Survey (URS) will be completed. The URS provides data to demonstrate that secondary side structures are suitable for unconditional release from the Site, i.e., free released as clean materials. This material is designated as Secondary Side Waste. For structures designated as R1, no radiological controls are required during demolition.

R2 is designated to structures that reside within the RCA where the radiological contamination is greater than the R1 levels, but less than the limits specified as being suitable for open air demolition (R2Open Air) or interior demolition (R2Interior). When the structure is scheduled for open air exterior demolition, R2Open Air controls are instituted mainly to protect the environment and public whereas R2Interior controls are instituted to protect the worker and to limit the potential for spread of

TSD # 10-002 Revision 00 Page 5 of 20 contamination to other interior areas. Prior to structure turnover for R2 demolition, a Contamination Verification Survey (CVS) will be completed to verify that pre-demolition contamination levels of primary side structures are below the limits established for open air or interior demolition. This material is designated as Primary Side Waste. For structures designated as R2, limited radiological controls are required, including but not limited to intermittent health physics coverage, misting, air sampling and periodic surveys.

R3 is designated to structures, or portions of structures, within the RCA where the radiological conditions exceed the R2Open Air or R2Interior criteria, as applicable. This material is also designated as Primary Side Waste. For structures designated as R3, significant radiological controls will be required.

These could include but are not limited to controls such as constant health physics coverage, application of surface fixatives, use of tents and HEPA ventilation, more intense air and surface sampling and personnel protective equipment such as respirators.

Table 1 shows the original radiological criteria for fixed and removable contamination levels adopted for demolition. These values were based upon regulatory requirements for R1 structures (e.g.,

no detectable licensed material for unrestricted release of materials) and estimates of the potential radiological consequences and controls for the demolition.

Table 2 - Original Contractual Radiological Control Indicators Demolition Total Surface Loose Surface Contamination Category Contamination

/ /

R1 Non Detectable Non Detectable Non Detectable Open Air 2 2 2 R2 500,000 dpm/100cm Max 1000 dpm/100cm Max 20 dpm/100cm Max 2

50,000 dpm/100cm Avg Interior 10 mR/h Contact 2 2 R2 10,000 dpm/100cm Max 200 dpm/100cm Max 2

>R2 and <100 mR/h >R2 and <100,000 >R2 and <5000 dpm/100cm R3 2 Contact dpm/100cm Max Max In 2004 Connecticut Yankee released the Decommissioning Operations Contractor (DOC) and resumed management of the decommissioning. Thus the contractual criteria were no longer relevant.

To ensure the criteria in Table 1 would meet the open air demolition objectives, testing was performed on concrete surfaces in the Primary Auxiliary Building (PAB) to determine empirically the proper R2Open Air fixed contamination levels and the acceptable removable contamination levels were reevaluated. The objective of the test was to determine the appropriate contact count rate or dose rate on concrete at which the concrete could be demolished or sized and meet the four objectives summarized at the end in section 4.2. The results of the evaluation and tests are summarized in the following section. The supporting data and surveys are available in the CY Technical Support Document (Ref. 8.5).

5.0 Calculations or Evaluations 5.1 Summary of Connecticut Yankee Removable Contamination Limit Evaluation During plant operations and decommissioning all of the open air demolition objectives have been met by maintaining the loose surface contamination levels below 1000 dpm/100 cm2 beta/gamma and 20 dpm/100 cm2 alpha on items stored or transported in outside areas. Any materials released off-site are

TSD # 10-002 Revision 00 Page 6 of 20 surveyed to less than detectable levels as defined by Nuclear Regulatory Commission Guidance. These levels are less than 5000 dpm/100 cm2 total beta/gamma contamination and less than 1000 dpm/100 cm2 removable beta/gamma contamination and less than 20 dpm/100 cm2 loose surface alpha.

In practice, containers, tools, equipment are deconned down to less than detectable contamination levels that range from 30 dpm/100 cm2 to several hundred dpm/100 cm2 depending on the survey method, instrumentation and background before they are released from buildings. The impracticality of instituting Conatminated Area Controls in outside areas, in addition to the regulatory scrutiny that such controls would illicit, is simply outweighed by the relative ease with which removable contamination can be fixed. Removable contamination is easily locked down by applying a fixative such as latex paint prior to demolition. It was determined that there was already sufficient precedent and experience to justify use of these practices as acceptable targets for R2Open Air removable contamination limits. To meet the above objectives removable contamination limits for open air demolition should not exceed 1000 dpm/100 cm2 and should on average be less than 300 dpm100 cm2./

5.2 Summary of Connecticut Yankee Concrete Demolition Test Results The relevant question was what levels of fixed contamination would be acceptable to maintain loose surface contamination levels below 300 dpm/100 cm2 during demolition. Maintaining loose surface contamination levels within acceptable ranges depends upon the amount of loose radioactive material present on the structure at the time of demolition and the amount of radioactive material that is liberated during the demolition process. Conventional demolition uses large excavators with hydraulic rams to rubbelize concrete and mechanical or thermal methods to cut metallic materials. Embedded or fixed contamination surficial and becomes loose as part of the dust generated when the concrete is fractured or cut by the demolition equipment. Typically, the vast majority of the contamination in the concrete surfaces of building interiors is embedded in the upper most portion near the surface. Most of the concrete structure and rebar is not contaminated and therefore the fracture dust and metallic dust or cutting smoke is clean. Contaminated surface fracture dust is diluted by uncontaminated dust from subsurface material. To develop an R2Open Air fixed contamination limit for concrete, the relationship between fixed contamination levels as indicated by surface dose rates and the resulting loose surface contamination limits from the dust liberated was evaluated. Tests were conducted at Connecticut Yankee to determine this correlation empirically, rather than by calculation.

In order to determine the appropriate R2Open Air fixed contamination criteria for concrete a series of in-situ tests were conducted in the Primary Auxiliary Building (PAB). The PAB was chosen because it had a series of cubicles which could be sealed off to contain dust and contamination and had concrete floors exhibiting a range of contact dose rates which varied from as low as no detectable contamination to as high as 20 to 30 mR/hr contact. The objective of these tests was to rubbelize concrete surfaces with different contact dose rates in the absence of engineering controls or dust suppression methods, and monitor the airborne radioactivity and removable contamination levels generated.

The tests were performed by pre-surveying the area to determine average contact dose rates in order to select a test location with the appropriate contact levels to be evaluated. The cubicle was then locked down to provide low levels of initial removable contamination and sealed off using poly tenting with no negative ventilation applied. This provided an environment in which airborne radioactivity levels and removable contamination levels resulting directly from the demolition could be evaluated. A test location was then remediated with an air sample running during the remediation. The concrete

TSD # 10-002 Revision 00 Page 7 of 20 remediations were performed using needle guns and jack hammers. After the remediation was completed, the test area and cubicle contamination levels were assessed by smear survey and large area swipes (LAS). The test area was also re-surveyed to determine the post remediation contact dose rates and evaluate the source term removed.

The first test area was in B Charging Pump Cubicle. The Test 1 surveys, air samples and demolition debris gamma spectroscopy results are provided in Attachment 1 of reference 8.5. The pre-remediation survey date is 3-3-04 at 16:00. The average pre-remediation contact dose rate is 0.66 mR/hr. Table 3 summarizes the test area data from this survey.

Table 3 - Test 1 Pre-remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 cpm 31 < MDA < MDA NDA 1.5 8,000 2 62.17 < MDA 32 < MDA < MDA 0.7 14,000 4 122.84 < MDA 33 < MDA < MDA 0.6 13,000 23 62.17 < MDA 34 < MDA < MDA 0.7 40,000 34 79.5 < MDA 35 < MDA < MDA 0.9 28,000 37 105.51 < MDA 36 < MDA < MDA 0.8 28,000 39 62.17 < MDA 37 < MDA < MDA 0.4 40 62.17 < MDA 38 < MDA < MDA 0.3 39 < MDA < MDA 0.3 A NDA 40 < MDA < MDA 0.4 B NDA 41 < MDA < MDA C NDA 42 < MDA < MDA 43 < MDA < MDA Average 0.66 21,833 Average 79.50 The remediation was conducted on 3-4-04. The post remediation survey provided in Attachment 1 of reference 8.5 was conducted at 12:00 P.M. on that date. The post remediation survey data is summarized in Table 4. This data shows that smear survey removable contamination levels remained well below 1000 dpm/100 cm2 in the cubicle. LAS survey results increased from pre-remediation levels of No Detectable Activity (NDA) to 3000 cpm in the cubicle. In addition, surveys of the remediation tooling, booties and gloves showed no detectable removable activity. The gamma spectroscopy results from the remediation dust and debris are shown in Table 5.

Air sample results indicated very low levels of gross beta/gamma activity at 8.66E-12 µCi/cc or 0.043 DAC. A sample of the fines and concrete chips generated during the remediation showed the activity of Co-60, Cs-134 and Cs-137 in the concrete. The gross activity on the air sample was scaled to the radionuclide fraction in the debris and compared to the 10 CFR 20 Appendix B Table 2 Effluent Concentrations for Air in Table 5. This showed that even though the remediation was performed in a tented cubicle with no dust suppression, ventilation or engineering controls, the resulting airborne radioactivity was well below the 10 CFR 20 Effluent Concentrations.

Table 4 - Test 1 Post Remediation Survey Data

TSD # 10-002 Revision 00 Page 8 of 20 Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 cpm 21 62.17 < MDA NDA 0.2 5,000 10 62.17 < MDA NDA 22 < MDA < MDA 0.3 1,000 11 235.53 < MDA 23 < MDA < MDA 0.6 5,000 21 53.5 < MDA 24 < MDA < MDA 0.7 8,000 29 131.51 < MDA 25 < MDA < MDA 0.5 10,000 26 < MDA < MDA 0.3 15,000 A 3000 27 < MDA < MDA 80,000 B 3000 28 < MDA < MDA 25,000 C 3000 29 79.5 < MDA 10,000 30 < MDA < MDA Average 70.835 0.43 17,667 Average 120.68 Table 5 - Test 1 Debris Gamma Spectroscopy Results A second area in Charging Pump Cubicle B with higher contact dose Scaled Air Eff. EC rates was selected for a second test.

Debris Fraction Sample Conc Weighted This area had contact dose rates in Nuclide uCi/gm of Total uCi/cc uCi/cc Fraction the 1 to 2 mR/hr range with an Co-60 2.77E-05 2.56E-02 2.21E-13 5.00E-11 4.43E-03 average contact dose rate of Cs-134 1.01E-05 9.35E-03 8.09E-14 2.00E-10 4.05E-04 approximately 1.5 mR/hr.

Cs-137 1.04E-03 9.65E-01 8.36E-12 2.00E-10 4.18E-02 Total 1.08E-03 1.00E+00 8.66E-12 4.66E-02 The Test 2 pre-remediation survey was conducted on 3/8/04 at 11:00 A.M. The data for the survey area is shown in Table 6. The average pre-remediation contact dose rate is 1.4 mR/hr.

TSD # 10-002 Revision 00 Page 9 of 20 Table 6 - Test 2 Pre-remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma Alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 1 < MDA < MDA NDA 1.5 50,000 11 < MDA < MDA 2 < MDA < MDA 1.2 16,000 12 < MDA < MDA 3 < MDA < MDA 1.7 25,000 13 < MDA < MDA 4 < MDA < MDA 1.9 15,000 14 < MDA < MDA 5 < MDA < MDA 1.4 20,000 15 < MDA < MDA 6 < MDA < MDA 1.2 75,000 16 < MDA < MDA 7 < MDA < MDA 1.7 75,000 8 < MDA < MDA 2 30,000 9 < MDA < MDA 1.2 10,000 A 200 1.2 B 200 NOTE: Not All Contact Dose 1.4 C Bkg Rates Are Shown In Table 1.5 D Bkg 1.5 E Bkg 1.2 F Bkg Average < MDA < MDA 1.4 35,111 Average < MDA < MDA 200 The Test 2 Post Remediation Survey was conducted on 3/9/04 at 09:00. The post remediation surveys are provided in Attachment 2 of reference 8.5. The data is summarized in Table 7.

Table 7 - Test 2 Post-remediation Survey Data Test Area Removable Test Area Contact Cubicle Removable beta/gamma alpha alpha dpm/100 dpm/100 LAS beta/gamma dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location dpm/100 cm2 cm2 ccpm 5 261.53 < MDA 1.5 18,000 1 <MDA < MDA NDA 6 88.17 < MDA 6,000 2 200.86 < MDA 7 < MDA < MDA 47,000 3 192.19 8 105.51 < MDA 16,000 4 235.53 9 183.52 < MDA 11 <MDA 10 96.84 < MDA 12 <MDA 13 <MDA E 200 14 <MDA 15 88.17 16 96.84 17 131.51 18 62.17 A 100 B 150 C 150 D 100 E 200 Average 147.114 1.50 21,750 Average 143.90 140

TSD # 10-002 Revision 00 Page 10 of 20 It can be seen by the comparing post remediation removable contamination levels in Table 4 and Table 7, that there was an overall increase in the extent and levels of contamination in the cubicle.

However, the contamination levels remained below the 1000 dpm/100 cm2 loose surface beta/gamma objective. The air sample during the remediation was 2.47E-11 uCi/cc or 0.124 DAC. Table 8 shows the anticipated effluent concentration for this air sample is 0.14 effluent concentrations. This is higher than the Test 1 air sample results.

Test 3 was conducted on an Table 8 - Test 2 Air Sample Data area with average contact dose Scaled rates of approximately 1.7 Air Eff. EC Fraction Sample Conc Weighted mR/hr. As shown in the test 3 dpm/smr of Total uCi/cc uCi/cc Fraction surveys provided in Attachment Co-60 2.15E+02 3.91E-02 9.65E-13 5.00E-11 1.93E-02 3 of reference 8.5, the cubicle Cs-134 5.89E+01 1.07E-02 2.64E-13 2.00E-10 1.32E-03 was shown to be at low Cs-137 5.24E+03 9.50E-01 2.35E-11 2.00E-10 1.17E-01 removable contamination levels Total 5.51E+03 1.00E+00 2.47E-11 1.38E-01 on 3/9/04 at 15:30. The pre-remediation contact dose rates are the ones at the left hand side of the test area shown in survey 04-1758 conducted on 3/10/04 at 10:00. This data is summarized in Table 9.

Table 9 - Test 3 Pre-remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 1.2 10,000 1 <MDA 2.5 15,000 2 1.4 50,000 3 2 15,000 4 1.3 20,000 5 6

Average < MDA < MDA 1.7 22,000 Average < MDA < MDA The post remediation survey was conducted on 3/10/04 at 15:30. The post remediation survey results are shown in Table 10. These results show similar removable contamination levels to those in Test 2 (Table 6).

TSD # 10-002 Revision 00 Page 11 of 20 Table 10 - Test 3 Post Remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 1.3 10,000 1 <MDA < MDA 1.2 9,000 2 <MDA < MDA 1 2,000 3 <MDA < MDA 1.9 4,000 4 200.2 < MDA 1 2,500 5 86.2 < MDA 1 8,000 6 71.9 < MDA 0.8 25,000 7 <MDA < MDA 7,000 8 90.9 < MDA 1,000 9 171.7 < MDA 9,000 10 79.8 < MDA 11 <MDA < MDA 12 131.3 < MDA 13 163.6 < MDA 14 <MDA < MDA A 125 B 125 C 200 D 175 Average 1.17 7,750 Average 124.45 156.25 As shown in Table 11, a Table 11 - Test 3 Air Sample Data composite sample of the concrete Air Sample Result 1.11E-10 uCi/cc Cs-137 chips from this area was obtained 2.04E-10 Total on 3/10/04 at 14:00. The sample Gamma Spectroscopy Results - Chips was analyzed by gamma Scaled spectroscopy and showed Co-60, Cs-137 Air EC Cs-134, Cs-137 and Am-241. The Scaling Sample Eff. Conc Weighted airborne radioactivity was uCi/gm Factor uCi/cc uCi/cc Fraction significantly higher than was Co-60 1.13E-04 3.72E-02 4.14E-12 5.00E-11 8.28E-02 documented in test 2. The air Cs-134 3.54E-05 1.16E-02 1.30E-12 2.00E-10 6.49E-03 Cs-137 3.04E-03 1.00E+00 1.11E-10 2.00E-10 5.57E-01 sample showed 1.114E-10 µCi/cc Am-241 1.34E-06 4.41E-04 4.92E-14 2.00E-14 2.46E+00 of Cs-137. When this Cs-137 Total 3.19E-03 1.17E-10 4.50E-10 3.10E+00 level is scaled to the concrete chip sample results, the Effluent Concentration is 3.10, exceeding the 10 CFR 20 Appendix B Effluent Concentration Limit for Air. However Zion does not have a transuranic source term. Without the Am-241 the EC was 6.46E-1.

TSD # 10-002 Revision 00 Page 12 of 20 Test 4 was also conducted in B Charging Pump Cubicle and was designed to test the contamination and airborne radioactivity levels resulting from 5 mR/hr concrete. The pre-remediation survey was performed on 3/17/04 at 13:30. The surveys are provided in Attachment 4, the data is summarized in Table 12.

Table 12 - Test 4 Pre-Remediation Survey Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 8 25,000 1 < MDA < MDA 7 32,000 2 < MDA < MDA 4.5 10,000 3 < MDA < MDA 2 16,000 4 < MDA < MDA 6 17,000 5 68.4 < MDA 2.6 18,000 6 < MDA < MDA 1.6 13,000 7 < MDA < MDA 9.5 9,000 8 < MDA < MDA 2.2 8,000 9 99.2 < MDA 2 18,000 10 49 < MDA 4.5 1,200 11 80.2 < MDA 1.2 12 < MDA < MDA 13 < MDA < MDA 14 < MDA < MDA 15 101.6 < MDA 16 54.1 < MDA B NDA C 275 D 25 Average < MDA < MDA 4.3 15,200 Average 75.42 150 The pre-remediation survey data shows the removable contamination to be low and intermittent. The post remediation survey was performed on 3/17/04 at 14:30 and is summarized in Table 13.

TSD # 10-002 Revision 00 Page 13 of 20 Table 13 - Test 4 Post Remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 31 < MDA < MDA 8 32,000 1 130.1 <MDA 32 < MDA < MDA 20 38,000 2 <MDA <MDA 8 12,000 3 <MDA <MDA 5 50,000 4 <MDA <MDA 18 50,000 5 355.8 <MDA 13 22,000 6 348.9 <MDA 8 8,000 7 189.5 <MDA 22 45,000 8 170.5 <MDA 8 18,000 9 113.5 <MDA 5 50,000 18 <MDA <MDA 13 22,000 19 <MDA <MDA 2.8 18,000 20 49.3 <MDA A 200 B 100 C 125 Average 10.90 Average 193.94 141.67 Due to an embedded pipe, the dose rates increased as the remediation proceeded. The test was abandoned because it was not possible to correlate the contamination levels with concrete contact dose rates.

TSD # 10-002 Revision 00 Page 14 of 20 Test 5 was conducted in the PAB Metering Pump Cubicle. The Pre-remediation contact dose rate survey was performed on 3/18/04. The pre-remediation smear survey was performed on 3/23/04.

The surveys are provided in Attachment 5, the data is summarized in Table 14.

Table 14 - Test 5 Pre-remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 2 227.5 < MDA 1.5 1 73.1 < MDA 2.5 3 118.2 < MDA 2 4 132.5 < MDA 2.5 50,000 5 130.1 < MDA 3.2 6 156.3 < MDA 2.8 7 172.9 < MDA 2 8 80.2 < MDA 10 9 144.4 < MDA 17 10 106.4 < MDA 3.8 11 244.2 < MDA 7 12 184.8 < MDA 10 13 142 < MDA 4.5 14 70.7 < MDA 8 15 427.1 < MDA 7.2 16 182.4 < MDA 3.5 17 172.9 < MDA 3.2 18 187.1 2.5 19 123 3.5 20 85 A 250 B 300 C 200 D 400 Average < MDA < MDA 5.1 Average 154.38 288

TSD # 10-002 Revision 00 Page 15 of 20 The post remediation survey was performed on 3/24/04. The results are summarized in Table 15.

Table 15 - Test 5 Post Remediation Survey Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 2 56.5 < MDA 1.5 5,000 1 244.2 < MDA 2 10,000 3 146.8 < MDA 1.5 30,000 4 158.6 < MDA 2.2 12,000 5 144.4 < MDA 3 20,000 6 80.2 < MDA 2.3 50,000 7 146.8 < MDA 2.2 8,000 8 151.5 < MDA F 400 4.5 46,000 9 66 < MDA 4.5 45,000 10 104 < MDA 11 75.5 < MDA 12 146.8 < MDA 13 104 < MDA 14 <MDA < MDA 15 115.9 < MDA 23 87.4 < MDA 24 89.7 < MDA 25 <MDA < MDA 26 56.5 < MDA 27 94.5 < MDA 28 49.3 < MDA 29 74.1 < MDA 30 54.1 < MDA 31 <MDA < MDA 32 61.2 < MDA A 330 B 330 C 280 D 430 Average 56.5 2.63 Average 107.21 342.5

TSD # 10-002 Revision 00 Page 16 of 20 The pre-remediation and post remediation removable contamination results are similar because a thorough pre-remediation decontamination of the area was not performed. However, they were detectably not elevated by the demolition activity.

Table 16 - Test 5 Air Sample Results A composite sample of the Air Sample Result 1.85E-10 uCi/cc Cs-137 concrete chips from test 5 1.42E-10 Total was analyzed by gamma Gamma Spectroscopy Results - Chips spectroscopy. The results Scaled identified Cs-134 and Cs-Cs-137 Air Eff. EC 137 at the concentrations Scaling Sample Conc Weighted shown in Table 16. The air uCi/gm Factor uCi/cc uCi/cc Fraction sample had 1.85 E-10 Co-60 1.29E-05 1.83E-03 3.39E-13 5.00E-11 6.78E-03 uCi/cc of Cs-137. When the Cs-134 0.00E+00 0.00E+00 2.00E-10 0.00E+00 air sample is scaled to the Cs-137 7.02E-03 1.00E+00 1.85E-10 2.00E-10 9.25E-01 concrete chip gamma Total 7.03E-03 1.85E-10 4.50E-10 9.32E-01 spectroscopy results and adjusted to effluent concentrations, the results are just below an effluent concentration.

Test 6 was performed on an area adjacent to test 5. This was an additional test to verify that remediation of concrete in the 2 mR/hr range would meet the contamination control objectives of the Open Air demolition criteria. The pre-demolition smear survey was performed on 3/25/04 at 10:30 and is provided along with the other data in Attachment 6 of reference 8.5. The pre-demolition contact dose rate survey was performed on 3/25/04 at 14:30. The pre-demolition survey data is summarized in Table 17.

TSD # 10-002 Revision 00 Page 17 of 20 Table 17 - Test 6 Pre-remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 19 127.7 < MDA 2.3 20,000 1 <MDA < MDA 1.5 25,000 3 104 < MDA 1.8 15,000 4 87.4 < MDA 1.9 16,000 5 99.2 < MDA 0.8 10,000 6 118.2 < MDA 1.2 2,000 7 111.1 < MDA 1.5 12,000 8 125.54 < MDA 1.2 49,000 9 70.7 < MDA 1.2 35,000 10 111.1 < MDA 0.8 42,000 11 <MDA < MDA 0.8 12 99.2 < MDA 1 13 61.2 < MDA 1.4 14 87.4 < MDA 1.1 15 73.1 < MDA 1 16 54.1 < MDA 1 17 80.2 < MDA 1 18 182.4 < MDA 0.8 20 94.5 < MDA 0.6 21 127.7 < MDA 0.1 1 A 120 0.8 B 220 0.8 C 120 0.6 D 220 Average < MDA < MDA 1.1 22600 Average 99.24 170 The post remediation survey was conducted on 3/29/04 at 10:30. This data is summarized in Table 18.

TSD # 10-002 Revision 00 Page 18 of 20 Table 18 - Test 6 Post Remediation Survey Data Test Area Test Area Removable Contact Cubicle Removable beta/gamma alpha beta/gamma alpha dpm/100 dpm/100 LAS dpm/100 dpm/100 LAS Location cm2 cm2 ccpm mR/hr cpm Location cm2 cm2 ccpm 4 <MDA < MDA 0.3 1,800 1 < MDA < MDA 5 <MDA < MDA 0.4 4,300 2 < MDA < MDA 6 56.13 < MDA 0.6 4,800 3 < MDA < MDA 0.3 2,200 7 < MDA < MDA 0.3 8,200 8 64.8 < MDA 0.5 15,200 9 <MDA < MDA 0.2 2,200 10 73.5 < MDA 0.4 7,200 11 125.5 < MDA 0.4 3,200 12 73.5 < MDA 13 <MDA < MDA 14 <MDA < MDA 15 <MDA < MDA 16 <MDA < MDA 17 56.1 < MDA 18 <MDA < MDA 19 <MDA < MDA 20 <MDA < MDA 21 <MDA < MDA 22 <MDA < MDA 23 64.8 < MDA 24 <MDA < MDA 25 108.13 < MDA 26 <MDA < MDA 27 64.79 < MDA A 260 B 240 C 300 D 125 Average 56.13 0.38 Average 78.88 231.25 Table 19 - Test 6 Air Sample Results This data Air Sample Result 2.41E-11 µCi/cc showed no significant Gamma Spectroscopy Results - Masslin change in area contamination levels Scaled and a slight increase in Air Eff. EC Fraction Sample Conc Weighted Large Area Smear uCi/g of Total uCi/cc uCi/cc Fraction results.

Co-60 7.13E-05 1.72E-02 4.25E-13 5.00E-11 8.50E-03 A LAS sample Cs-134 4.11E-06 9.91E-04 2.45E-14 2.00E-10 1.22E-04 of the concrete dust Cs-137 4.07E-03 9.82E-01 2.43E-11 2.00E-10 1.21E-01 generated during the Total 4.15E-03 1.00E+00 2.47E-11 1.30E-01

TSD # 10-002 Revision 00 Page 19 of 20 remediation was analyzed by gamma spectroscopy. The results are shown in Table 19. The air sample obtained during the remediation was 2.41E-11 uCi/cc. When scaled to the gamma spectroscopy results, it is well below the effluent concentrations.

Based on the results from Tests 1, 2, 3 and 6, remediation of concrete with overall contact dose rates at or below 2 mR/hr on contact results in minimal increase in airborne radioactivity or removable contamination levels. Due to difficulties in executing tests 4 and 5, the tests did not prove definitively an upper limit at which removable contamination levels become unacceptably high. Therefore, the 2 mR/hr on contact limit is not an absolute upper limit, but an overall objective to ensure the open air demolition objectives will be met.

6.0 Conclusions

.Based upon the comparison to other facilities open air demolition limits and the results of the Connecticut Yankee tests, the following open air demolition limits are recommended.

Table 20 - Recommended Open Air Demolition Limits Demolition Total Surface Loose Surface Contamination Category Contamination

/ /

Open Air 2 2 R2 2 mR/hr contact 1000 dpm/100cm Max 20 dpm/100cm Max 2

Greater than 2 mR/hr 300 dpm/100cm Avg.

contact other material other than concrete as authorized by RP As stated in the first section of this TSD, the objectives of the open air demolition limits were the following:

1. Ensure ground level airborne radioactivity levels remain ALARA and within regulatory limits.

Qualitative air samples were established around open air demolition perimeters during open air demolition and demolitions were conducted without detectable airborne radioactivity releases.

2. Ensure demolition liquid concentrations remain at levels which can be collected, processed and released using plant water treatment systems and discharge points.

The low average surface contamination levels ensured construction grade water associated with open air demolition could be collected and processed using clarifiers and filtration without ion exchange resins required for processing and release.

3. Minimize the spread on contamination within the site boundary such that there is not significant effect on groundwater or the scope of soil remediation required for License Termination.

Open air demolitions were conducted without impacting license termination Derive Concentration Guideline Limits for soils or groundwater.

4. Ensure open air demolition activities can be conducted using conventional demolition techniques with minimal radiological restrictions or controls.

Open air demolitions were conducted without personnel or equipment contamination.

TSD # 10-002 Revision 00 Page 20 of 20 7.0 Attachments 7.1 None 8.0 References 8.1 San Onofre Unit 1, HP&E Position Paper, Airborne Effluent Controls During Decommissioning, September 27, 2000.

8.2 Maine Yankee, Technical Evaluation TE-013-01, Radiological Consequences of Hotside Building Demolition, October 10, 2002.

8.3 Yankee Rowe, RP-Memo File No.03-024, Airborne Effluent Dose Consequences of Building Demolition, September 3, 2003.

8.4 Technical Support Document CY-HP-0029, Rev. 0, HEPA Units Environmental Release Evaluation February 9, 1999.

8.5 Technical Support Document CY-HP-0175, Rev. 0, Technical Basis for Structure/Building Open Air Demolition January 19, 2005.