ML102700538

Humboldt Bay Marsame Survey Package - Structural Steel

ML102700538
Person / Time
Site:	Humboldt Bay
Issue date:	06/25/2010
From:	Bartlett Services
To:	NRC/FSME
References
HBPP-SS-001
Download: ML102700538 (26)

Text

Humboldt Bay Power Plant MARSAME Survey Package HBPP-SS-001 Structural Steel Reviewed by: Approved by: (Original Sgqned 6/25/2010)

RP Engineer (Oriainal Sioned 6/25/2010)

RP Manager Prepared by: (' BARTL ETT SERVICES, INC.60 Industrial Park Road Plymouth Massachusetts 02360 Structural Steel HBPP-SS-001

1.0 OBJECTIVE

The objective is to make an appropriate disposition decision regarding the HBPP Unit 1 and Unit 2 structural steel.2.0 BACKGROUND The structural components of Unit 1 are composed of various sized steel beams. The structure encompasses 8 elevations with the majority of the upper 6 elevations open to the environment.

The Unit 2 structure is virtually a carbon copy of the Unit 1 structure.

This document deals with the structural steel present in both Unit 1 and Unit 2.This survey plan was developed in accordance with HBAP RCP-6Q, MARSAME Disposition of Materials and Equipment

[13.1 ].3.0 INITIAL ASSESSMENT A visual inspection of Units 1 and 2 was performed on November 3, 2009. The structures appeared to be in good shape.Following the visual inspection a review of documents was performed.

The following documents were reviewed:* HBAP D-500, Documenting Site Radioactive Contamination During SAFSTOR, Rev. 6A* SAFSTOR Decommissioning Plan for the Humbolt Bay Power Plant, Unit 3 Rev.1 July, 1994* SAFSTOR Environmental Report, July, 1984 0 023BS2, Characterization of Unit 1Building Structure, November, 2008 The potential impact to the structural steel due to deposition from radioactive gaseous effluent discharges was evaluated in the initial assessment.

Historical meteorological data indicated that, approximately 55% of the time, the prevailing winds at the HBPP site are from the northerly direction, ranging from approximately 3200 to 200. Approximately 25% of the time gaseous effluents would have been discharged into relatively calm air resulting in an evenly distributed deposition of activity onsite, potentially impacting the structural steel of the structures.

The wind direction and potential deposition and "washout" hold the possibility of impacting those portions of the steel that were exposed to the environment.

A much less impact is to the portions that are enclosed.A characterization survey was performed on the structures on 6/24/08 through 8/19/08. The survey consisted of beta scans and fixed-point measurements performed on the structural steel.The majority of the measurements that were taken in the protected areas of the steel yielded less than MDC measurements.

Table 3.1 below presents the data that were greater than the static MDC for the measurement.

The measurements listed in the table indicated readings that were greater than the MDC for the measurement albeit within the statistical variation of the measurement.

Notwithstanding, it is prudent to assume that the exterior surfaces of the structural steel are impacted.2 Stnructurl qtppl HBPP-SS-001 Structural StAeI HBPP-SS-OO1 Table 3.1 Characterization data (dpm/1OOcm 2)189 .212 189 345 282 283 366 542 298 40 211 199 171 153 377 269 263 234 211 226 516 223 305 159 293 235 263 412 272 189 351 327 281 339 198 298 Mean 270 Median 266 Std Dev 98 4.0 CATEGORIZATION Based on the results of the IA, the exterior surfaces of the structural steel components are categorized as impacted.5.0 CLASSIFICATION

5.1 Survey

Unit Classification The exterior surfaces of the structural steel components are not expected to contain plant-related radioactivity that exceeds background levels in any great magnitude and, therefore, are classified as Class 3 M&E.

6.0 DESCRIPTION

6.1 Physical

Attributes 3

Structural Steel HBPP-SS-001 Table 6.1 lists the physical attributes of the structural steel.Table 6.1: Physical Attributes of Structural Steel Attribute Description Volume Approximately 1.5X1 06 pounds per unit of various sized steel.Some sections of steel are small and do not permit surveying (examples of Complexity structural steel are shown in Figures 1 through 9).Much of the steel is currently inaccessible and therefore will be surveyed after Accessibility demolition The large sections of steel have inherent value as recycle. The steel in the Inherent upper, inner sections would require remediation before release. A large scale value remediation effort for these steel components would not be economical.

6.2 Radiological

Attributes Table 6.2 lists the known radiological attributes associated with structural steel. As presented, the existing information for structural steel is adequate to design a disposition survey.The primary radionuclide of potential concern is Cs-1 37.Table 6.2: Radiological Attributes for Natural Gas System Attribute Description Data Gaps Radionuclides Principle Emission No data gap identified.

Emission Energy Radioactivity, if present is Particle (MeV) likely to have come in contact with the components by"washout" of activity contained in the effluent Cs-137 Gamma 0.661 releases from the stack.Activity Preliminary indications are that the gross No data gap identified.

surface activity measurements would be Estimates of background are close to background levels. The expected determined from a series of background range is approximately 20-270 measurements and therefore cpm. are adequate with no data gaps Distribution The activity, if present, would be evenly No data gaps are identified distributed across the surface of the components Location The activity, if present, would be distributed No data gaps are identified across the surface of the components more so on the tops than the sides and be fixed in nature 4 Structural Steel HBPP-SS-001

7.0 PRELIMINARY

SURVEYS There is sufficient information available to design a disposition survey without the need of preliminary surveys.8.0 DISPOSITION OPTIONS There are two primary disposition options for structural steel: recycle and disposal.

The lower elevations steel has been identified for the recycle disposition option. If the steel meets the recycle criteria, then it will be sent to the recycling facility.

Because there is inherent value to the steel components, if surface activity exceeds the recycle criteria, then the components will be evaluated for a simple decontamination effort and re-survey to the recycle criteria.

If the post-remediation activity exceeds the recycle criteria or the decision is made not to attempt remediation, then the steel component will be evaluated against the exemption criteria for burial at US Ecology.Structural steel located in the upper inner portions of the Units (identified in Figure 9) will be segregated at demolition and surveyed for burial at US Ecology. If surface activity of this steel meets the exemption criteria, then the steel debris will be sent for burial at US Ecology. If the surface activity exceeds the exemption criteria, the steel will be sent to Clive for burial. The determination of the burial site will be made by comparing the activity present to the action levels in Table 9.1B.9.0 SURVEY DESIGN 9.1 Null Hypothesis

• Null Hypothesis:

Unit 1 and 2 structural steel contains plant-related radioactivity equal to or above the action levels.9.2 Limits on Decision Errors* TVpe I: During scanning, the consequence of making a Type I decision error is the shipment of the lower elevation structural steel to the 'recycle facility when the activity level exceed the recycle criteria or the upper elevation steel to US Ecology when the activity levels exceed the exemption requirements.

A Type I decision error rate of 5% has been selected for the scanning survey." Type II: The consequence of this decision error may include the need to perform an investigation to determine the reason for the elevated reading, or the added expense of sending the material for burial. For this reason, a Type II decision error rate of 25% has been selected for the scanning.9.3 Decision Rule If all scans from the exterior surfaces of the structural steel indicate that the residual radioactivity does not exceed the action levels (shown in Tables 9.1A and 9.1B), then reject the null hypothesis.

The structural steel meets the recycle criteria or the US Ecology exemption criteria.If scans from the exterior surfaces of the structural steel indicate that the residual radioactivity exceeds the action levels for targeted disposition actions,'then accept the null hypothesis.

5 Structural Steel HBPP-SS-001

9.4 Alternative

Actions Alternative action to the recycle disposition option is disposal at US Ecology. For the upper inner steel, the alternative action to the disposition action of disposal at US Ecology is disposal at the Clive burial site. If the survey results indicate that a section, or sections, of the structural steel exceed the action level for the primary disposition option, then those sections may be separated and segregated for the alternate disposition cited above.9.5 Radionuclide-of-Concern Cs-137 has been selected as the radionuclide-of-concern through the application of characterization data for Unit 3 steel.9.6 Action Levels The detectability requirements for release of items from a radiologically controlled area (RCA) are shown in Table 9.1A. The scan MDC value will be set as the action level for the surveys of the surfaces of structural steel.The scan action levels for the recycle of structural steel and burial of the upper inner steel components at US Ecology are listed in Tables 9.1A and 9.1B, respectively.

Table 9.1A: Action Levels for Surface Scan Surveys for Recycle Detectability Requirements for Beta Contaminationa Scan Action Level Radionuclide (dpm/100 cm 2) (dpm/100 cm 2)Cs-137 5000 (total) Scan MDC 1000 (removable) aValues from section 5.1 in procedure RCP-6B.The actual scan action level for recycle surveys will depend on the level of background radiation in the area of Unit 1 and 2 structural steel components at the time of the survey. Any measurement exceeding the scan MDC value for the background radiation level existing at the time of the survey will constitute exceeding the Action Level.Table 9.1B: Action Levels for Surface Scan Surveys for Burial at US Ecology Radionuclide Waste Limita ScanAction Levelb (pCi/g) (dpm/100 cm 2)Cs-137 15.0 130,000 aValue from Table 1 in PG&E Letter HBL-10-003.

bValue based on density equal to 7.86 g/cm 3 and assumes 2-inch thickness of steel.Value shown has been rounded down to 2 significant digits.The Action Levels for this survey are equal to the UBGR.6 (Zfm pfliir~l Q#-I

9.6 Discrimination

Limit The discrimination limit (DL) is the level of activity that can be reliably distinguished from the action level by performing measurements.

For all surveys performed under this plan, the DL is the background radiation level. All survey techniques must be able to identify radiation levels that exceed the background radiation level present at the time of the surveys.The discrimination limit for this survey (i.e., background) is equal to the LBGR.9.7 Survey Type 9.7.1 Measurement Techniques A scan survey design supplemented with judgmental (biased) fixed-point measurements is the preferred approach for structural steel.This survey design requires that the measurement method be capable of detecting radioactivity at the discrimination limit (i.e., background radiation levels). The scanning surveys will identify areas of elevated radioactivity.

The results from individual scans will be recorded and compared to the Action Levels.9.7.2 Measurement Quality Options 9.7.2.1 Measurement Uncertainty The characterization survey for structural steel included background measurements using the Ludlum 43-68 detector, the same type of detector that will be used in this survey. The expected range for the ambient background measurements in structural steel areas is approximately 20 cpm to 270 cpm. This background range has been applied for planning purposes.The required measurement uncertainty, PMR, for scans should be !'s/3, or !'bg/3.9.7.2.2 Detection Capability Scan Minimum Detectable Count Rate: The minimum detectable count rate (MDCR) is determined for the Ludlum 43-68 detector using equation 6-9 in MARSSIM [13.4]: MDCR = d'jii ( 6)Where: MDCR = minimum detectable count rate, cpm bi = average number of counts in the background observation interval i = observation interval length = 2.3 seconds d' = detectability index from Table 6.1 of NUREG-1507; a value of 1.38 is selected, which represents a true positive detection rate of 95% and a false positive detection rate of 60% interval (counts)7 HRPP-££-flfll-Itr"rt"ral Steel HBPP-SS-001 Table 9.2: MDCR Values Background Count Rate Scan MDCR (cpm) (cpm)20a 31 70 59 120 77 170 92 220 104 270b 116 a ApproximateLower end of expected background range.b Approximate Upper end of expected background range.Except for a very low background

(:55 cpm), the scan MDCR values shown in Table 9.2 are below the respective background count rates, indicating that the sensitivity of the Ludlum 43-68 detector is sufficient to meet the objective of this survey.A Type I error, missing a true elevated area, may lead to incorrectly exceeding the limit for the chosen disposition option. This will happen with probability

a. A Type II error, misidentifying a background area as elevated will have the consequence that a longer reading will be needed to verify the initial decision.

This will happen with probability P3.Scan Minimum Detectable Concentration:

The scan MDC is determined using the equation 6-10 in MARSSIM [13.4]: MDCR Scan MDC =A Where: MDCR = minimum detectable count rate (cpm)p.= efficiency of a less than ideal surveyor, range of 0.5 to 0.75 from NUREG-1507; a value 0.5 was chosen as a conservative value A = Area of the Ludlum 43-68 probe = 126 cm 2-i Es = weighted total efficiency for the Ludlum 43-68 = 0.12 c/d Table 9.3: Scan MDC Values for Recycle Surveys MDCR J Scan MDC (cpm) (dpm/100 cm 2)31a 295 59 551 77 722 92 859 104 977 116b 1083 a MDCR at lower end of expected background range.b MDCR at upper end of expected background range.8 (r i+l ir"-l Qf-l I-I P PP_c_.nn I For most of the expected background radiation levels for structural steel, the minimum detectable concentrations (MDC) for recycle scan surveys (shown in Table 9.3) using a Ludlum 43-68 detector are significantly below the HB detectability requirements, including the detectability limit for removable beta contamination.

However, at the upper end of the background range (i.e., 230 cpm) the scan MDC values indicate that a slower probe speed is required in order to meet the detectability requirements in procedure RCP-6B.The data shown in Table 9.3 were used to develop Figure 10.9.7.2.3 Detection Capability for Fixed-Point Measurements Critical value: Because the background for beta-gamma counts is expected to be high (i.e. >100), equation 1 from Table 7.5 in MARSAME [13.3] was used to determine the critical value: S c = z i_ t-3 t-Where: NB = background count ts = count time for the sample = 1 min tB = count time for the background

= 1 min Zia = (1 -a)-quantile of the standard normal distribution

= 1.645 Table 9.4: Critical Values at Various Backgrounds NB Sc (counts) (counts)20a 10 70 19 120 25 170 30 220 35 270b 38 a Lower end of expected background range.b Upper end of expected background range.Note that the values of Sc are a small fraction of the corresponding background values. A net count for a fixed-point measurement that exceeds the S, value will indicate the presence of residual radioactivity.

The data shown in Table 9.4 were used to develop Figure 11.Minimum detectable value of net instrument signal: The minimum detectable value of the net instrument signal, SD, for beta-gamma measurements is calculated using equation 1 from Table 7.6 in MARSAME [13.3].SD = So + (z 2 1/-p2) + zl-p

• square root [(z 2 1_p4) + So +NBtS/tB(l

+ ts/tB)]9 HRPP-qR-flO1 Where: Sc = critical value (counts)NB = mean background count ts = count time for the test source = 1 min tB = count time for the background

= 1 min zp= (1 -P3)-quantile of the standard normal distribution

= 0.6745 Table 9.5: SD Values Sc SD (counts) (counts)10a 15 19 28 25 37 30 43 35 49 38 55 a Sc at lower end of expected background range.b Sc at upper end of expected background range.5 The data shown in Table 9.5 were used to develop Figure 12.Fixed-Doint Measurement MDC: The minimum detectable concentration (MDC) for a beta-gamma measurement is determined by the equation: SD YD -e Where: YD = the MDC value (dpm)SD = the minimum detectable value of the net instrument signal e = the weighted total efficiency

= 0.12 c/d Table 9.6: Fixed-Point Measurements MDC Values Probe Area Adjusteda SD YD YD (cpm) (dpm) (dpm/I00 cm 2)15" 128 102 28 235 187 37 306 243 43 363 288 49 412 327 55c 455 361 a Probe area adjustment factor = 1/(126/100)

= 0.7937 b SD at the lower end of expected background range.c SD at the upper end of expected background range.The data shown in Table 9.6 were used to develop Figure 13.10 HRPP-Rs-001 Structural Steel 9.7.2.4 Range The expected background radiation level is approximately 20 -270 cpm. The scan MDC values and the MDC values for fixed-point measurements indicate that increases above the expected background radiation levels will be identified in surveys performed with the Ludlum 43-68 detector.9.7.2.5 Specificity Nuclide-specific measurements should not be required unless to assess the nuclide contribution to the gross activity.

If nuclide specific measurements are required, volumetric samples will be assayed by onsite laboratory equipment.

9.7.2.6 Ruggedness Ruggedness is not expected to be a major concern for selecting a measurement method. Because only surficial radioactivity is expected, scan measurements of the structural steel surfaces will be used to collect data for comparison to the action levels. The environmental conditions during the survey will likely be after the rainy season (October to April); however, due to the sensitive electronics in these instruments, surveys will not be performed in rainy conditions.

9.8 Survey

Boundaries This survey plan is limited to the external surfaces of structural steel materials.

9.9 Preparation

and Special Instructions During the scan surveys, the field supervisor for this survey will assure and verify that technicians adhere to probe speed and distance to source requirements.

The F&S Supervisor must evaluate the job hazards associated with the preparation activities and the scan surveys for structural steel prior to performing the work. Safety issues and specific safety requirements associated with this work will be included among the discussion topics in the pre-job briefing.Perform the scan surveys as follows: 1. Prior to the start of the survey, ensure that an operability check is performed for the survey instrumentation (i.e., Ludlum 43-68 detector and scaler) in accordance with procedure RCP 7-U2 [13.6].2. Perform five 1-minute ambient background counts in the area of the structural steel to be surveyed with the positioning of the detector greater than 1 meter from any surface.a. Determine the mean value of the 5 background measurements.

b. Using the mean background value and Figure 10, select the appropriate scan MDC value and record the scan MDC on the survey form (Figure 14).c. Using the mean background value and Figure 11, select the appropriate critical value (Sc) and record the S, value on the survey form (Figure 14).Note If the average background radiation level exceeds 230 cpm, the scan speed should be reduced from 2 inches per second to 1 inch per second.11 Structural Steel HBPP-SS-001

3. Using the audible function with headphones, perform the scan survey of the M&E.a, Maintain a 1/2 inch detector-to-surface distance during the survey b, Move the detector at a constant speed no greater than 2 inches per second.4. Upon an audible indicatioh of elevated radioactivity (i.e., >scan MDC value), stop and re-scan that area to confirm the increased audible response.a. If the initial response can not be reproduced, continue scanning.b. If the initial response is reproducible, 1) Compare the highest instrument response value that was observed during the scan to the background level.2) If the instrument response is greater than background, scan the area to identify boundaries of the elevated radioactivity.

2) Mark or otherwise identify the boundaries of the area of elevated radioactivity on the component being surveyed for decontamination and re-survey.

2) Collect a 1-minute fixed-point measurement at the location where the highest reading was observed during the scan and record the measurement on the survey form.3) Compare the net count of the fixed-point measurement to the critical value (Sc) determined in step 2c above.* If the net count is less than Sc, record that observation on the survey form and continue the scan survey.* If the net count is greater than So, record that observation on the survey form and notify the RP Supervisor of the confirmed elevated radioactivity.

5. Perform judgmental (biased) scan of areas of the steel where radioactive contamination may have accumulated.

If required by scan results, or determined by judgment or at the direction of the RP Supervisor, collect 1-minute fixed-point measurements and/or swipe samples from these areas.a. Record the location of the biased scans and fixed-point/swipe measurements on the survey map.b. For swipe measurements, clearly label the swipes and ensure that they are assessed for beta-gamma contamination.

c. For 1-minutefixed-point measurements, compare the net count of the fixed-point measurement to the critical value determined in step 2c above.* If the net count is less than Sc, record that observation on the survey form and continue the scan survey.* If the net count is greater than So, record that observation on the survey form and notify the RP Supervisor of the confirmed elevated radioactivity." If the net count exceeds 5000 dpm/100cm 2 inform RP Supervision for direction.

6. Ensure that all survey results are documented in accordance with HBPP RP procedures.

7. At the completion of the survey, perform a "post-use" instrument operability check in 12 Structural Steel HBPP-SS-001 accordance with procedure RCP 7-U2 [13.6].9.10 QARequirements Survey instrumentation and detectors will be calibrated in accordance with applicable HBPP procedures.

Instruments will be source checked prior to the start of the survey and at the conclusion of the surveying effort each day. If an instrument fails a post-survey source check the data collected from the time the instrument last passed a source check will be evaluated for accuracy.

Source checks will be performed and documented in accordance with applicable HBPP procedures.

Control charts should be maintained so as to track the performance of the instrumentation.

9.11 Survey Units The structural steel materials form a single survey unit.9.12 Inputs for the Selection of Provisional Measurement Methods The selected measurement method will be required, at a minimum, to detect radionuclide concentrations at or below the action level.9.13 Reference Area No reference area has been chosen because it is not expected that the materials associated with the survey unit would contain appreciable amounts of natural occurring radioactivity.

9.14 Optimization of the Survey Design A scan survey supplemented with biased fixed-point measurements will be performed of the exterior surfaces of structural steel materials.

Because the exterior is Class 3, the survey design consists of 100% scan survey of approximately 15% of the total external surface area of the structural steel. Professional judgment will be used to select the locations for the scans and swipe measurements.

The focus will be on locations with the highest potential for plant related radioactivity.

Experienced, qualified technicians will be used to perform the surveys. The scan speed will be 2 inches (5 cm) per second.However, if the background radiation level exceeds 230 cpm, the probe speed will be reduced to 1 inch per second. The scans will be performed using a 100 cm 2 gas proportional detector(Ludlum model 43-68).If while scanning, an area is perceived to exceed background (i.e., exceeds the scan MDC), the surveyor will perform an investigation survey consisting of a re-scan of the area to verify the result of the initial scan measurement.

If the results of the background corrected verification measurement exceed the scan MDC (i.e., exceeds background), the area of the elevated radioactivity will be determined and recorded on a survey map, and a fixed-point measurement will be collected and assessed.

The physical location of any scan verification measurement that exceeds the action level will be clearly marked on the component.

Judgmental (biased) measurements will be obtained from locations believed to be potential collection points of surface contamination.

9.15 Documentation of the Survey Design The disposition survey design will be documented in a survey package delivered to the HBPP RP Supervisor.

13 qtr 1 .r0l , t _-_l HRPP-ss-fln1 Str.... t.r.. e ...... ......10.0 SURVEY IMPLEMENTATION 10.1 Job Hazard Analysis Health and safety (H&S) hazards associated with the surveys of structural steel will be evaluated and documented in accordance with appropriate HBPP procedures.

The evaluation of the H&S hazards will also include preparation activities for the survey unit.The results of the H&S evaluation will be presented during the pre-job briefing to all personnel involved in the survey of structural steel.10.2 Survey Area Preparation Verification The HB F&S supervisor and survey supervisor will verify that all necessary precautions are in place prior to the conduct of the survey.11.0 SURVEY RESULTS 11.1 Survey Data Survey data will be recorded on the form provided by Figure 13. All survey records will be retained in accordance with procedure HBAP RCP-6Q [13.1].11.2 Data Quality Assessment Survey data will be reviewed, assessed, and documented in accordance with procedure HBPP RCP-6Q [13.1].12.0 DECISION All decisions regarding planned disposition options for structural steel will be based on and supported by the outcome of data assessment.

13.0 REFERENCES

13.1 HBAP RCP-6Q, MARSAME Disposition of Materials and Equipment 13.2 NUREG 1575, Supp. 1, Multi-Agency Radiation Survey and Assessment of Materials and Equipment Manual (MARSAME)13.3 NUREG 1575, Revision 1, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)13.4 HBPP-RPT-001, Revision 1, Radiological Characterization Report, Humboldt Bay Power Plant 13.5 HBPP Historical Site Assessment, Revision 2, September 2008 13.6 RCP 7-U2, Revision 0, Ludlum 2350-1 Source Check 13.7 RCP-6B, Revision 4A, Release of Solid Materials from Radiologically Controlled Areas 14

.qt Jrn I HBPP-SS-lO01 Structural Steel Figure 1: Layout of Unit 1 North and East Elevations 15 H-RPP-S.S-flO1 Structural Steel ItLwa ffff-,:::i ors 1:9 1 FA Em I kýa -Al- .-=F==F' FF E 7::.-W WST -LLIVATJ~4 P--S'FIIL' SiT5l " L4 C JU I ..ak9 mw -2.S.D F.C L.V.A.IIAJJ...... , (V-uACWITICIIJRAL DRAWIUC, IWDIX 4'fbNIfC CEWC M b, I I W, -0 N wCM OLN7 I.--4LME -i*-Ar-rni.

ME --' .:. i ......I W PWER BUILOI"Q SOaTIC & IET ELVAIOSI fi z75 , , ..,d.l* /Figure 2: Layout of Unit 1 South and West Elevations 16

-tnqfm r~flm H R I Rfnirtiirl

~tHBPP-SSp-00-n1 Figure 3: Units I and 2 Exterior View 17

.q, tn p.l HRPP-SS,-OO 1 Structural Steel HBPP-SS-001 Unit 1 +12' Interior 1 Figure 4: Unit I Interior 12-Ft Elevation 18 Qfr i-fl -1~ Q:f-wl)PP.-qq-rni Figure 5: Unit I Interior 27-Ft Elevation 19 Jrnl tnp.l HBPP-SS-O01 Structural Steel lIUl 56+ Structure 2 20 Qfrn irfi irnl UDDD cc, nn4 U1 73+ Structure 1 Figure 7: Unit I Exterior 73-Ft Elevation 21 Qf f I Qf- I i-iRpp..q.q.rlfl I HBPP-SS-001 U1 80+ Structure 3 NOR not Figure 8: Unit I Exterior 80-Ft Elevation 22

.q, trl Jrnl t ppl HRPP-SS-nn1 Structural Steel Figure 9: Inner portion of the structural steel to be segregated and shipped as radioactive waste (shown in white box)23

.q, tPAI Structural Steel HBPP-SS-001 1150 1050 950 850 750 650 550 450 350 250 U CL M 20 70 120 170 220 Background (cpm)270 Figure 10: Scan MDC for Various Background Radiation Levels 40 35 30o C, 25 "R 15 10 20 70 120 170 220 270 Background (cpm)Figure 11: Critical Values (Sc) for Various Background Radiation Levels 24 Jr.h uml HRPP-SR-O01 Structural Steel 55 50 45 E 40 35 _2 30 25 E.E 20 15 i i i .... .... .... .. ....1 0 20 70 120 170 220 270 Background (cpm)Figure 12: Minimum Detectable Value (SD) for Various Background Radiation Levels 400 350 300 250 : 200 "S 0 150 .100 20 70 120 170 220 270 Background (cpm)Figure 13: Fixed-Point Measurement MDC for Various Background Radiation Levels 25 Q4r ,ft ,rle It wppp-qq-nni 4.-l UI I,,-+,IIi lI-u-n MARSAME Package Number: Date: Surveyor: Survey Instrument (type): Pre-survey Check Sat Unsat Instrument Serial Number Post-survey Check Sat Unsat Cal due date: Smear results Scan Area Max Scan Static dpm/100 cm2 Coments cpm cpm Beta Background Measurements Location: cpm_1 2 Scan MDC: 3 Sc 4 5 Average Surveyor Signature:

Date: Reviewed by: Date: Figure 14: Structural Steel Survey Form 26