ML070380025

Yankee Response, Dated January 18, 2007, to NRC Questions on Final Status Surveys TBN-01, NOL-01, WST-01, AUX-01, and NSY-12

ML070380025
Person / Time
Site:	Yankee Rowe
Issue date:	01/18/2007
From:	Carson A - No Known Affiliation
To:	John Hickman, Youngblood T NRC/FSME/DWMEP/DURLD
References
Download: ML070380025 (16)

Text

John Hickman -Written responses to FSS questions Page 11I John Hickman -Written responses to FSS questions Page 1 From: "Alice Carson" <acarson 1967 @ comcast.net>

To: "'John Hickman"'

<JBH @ nrc.gov>, <thy@ nrc.gov>Date: 01/18/2007 3:18:42 PM

Subject:

Written responses to FSS questions John, Here are written responses to questions identified in your matrix. Please let me know if you require any additional information.

Regards, Alice Carson CC: "'Greg Babineau"'

<Babineau@yankeerowe.com>, <erickson@yankeerowe.com>, "'Joe Bourassa"'

<Bourassa@CYAPCO.com>, "'Gerard P. Van Noordennen"'

<VanNoordennen

@ CYAPCO.com>

Yankee and its NRC Project Manager, John Hickman, have recently undertaken a review of decommissioning correspondence to identify requests for additional information and any responses to those requests.

Through this review it was determined that there were three sets of emailed questions that had been discussed in teleconferences but for which no written response could be found. These questions centered on the first five final status survey reports submitted:

TBN-01, NOL-01, WST-01, AUX-01, and NSY-12. The attached pages document those questions as well as Yankee's responses to ensure closeout of these items. It is noted that a number of the questions prompted changes to the final status survey report structure of subsequent reports.Page 1 of 12 Additional Questions for April 10, 2006 Call (Email from John Hickman to Alice Carson dated Monday, April 10, 2006)NRC Question #1: YR indicates that ISOCS is not suitable for discrete hot particles.

How does YR plan to survey for discrete particles?

[ISOCS result provided for the 1.2 uCi Co-60 source was useful information.]

Yankee Response:

It is Yankee 's position that ISOCS is sutitablefor detecting discrete particles.

Yankee used both 1SOCS and SPA-3 for turnover surveys. Generally, the SPA-3 did not identify anything that the 1SOCS did not; although there were isolated cases where one instrument did identify a particle, and the other one had not. SPA-3 investigations following an elevated ISOCS result provide additional assurance that any existing contamination is appropriately identified.

YA-REPT-00-O01-06 and YA-REPT-00-12-06 provided to the NRC via email on June 19, 2006 discuss particle detection sensitivity for scan instrumentation, inchlding SPA-3 and ISOCS.NRC Question #2: Does YR have any empirical data using ISOCS for surface contamination measurements?

Yankee Response:

No, Yankee does not have empirical data for surface contamination.

Yankee committed together such data if activity was encountered, while performing subsequent surface measurements.

However, activity was not identified in subsequent measurements.

The basis for the use oflSOCS for surface contamination measurements is provided in modeling documented in YA-REPT-00-018-05, "Use of ln-situt Gamma Spectrum Analysis to Perform Elevated Measurement Comparison in Support of Final Status Surveys, " which discusses ISOCS modeling.NRC Question #3: YR & ORISE have reported results to NRC for the discrete particle identified in FSS-TBNOI-00 (0.2 uCi & 1 uCi). Have you discussed analysis results for the discrete particle with ORISE?Yankee Response:

No, Yankee has not seen the results. There are a number offactors to be considered in the analysis, all of which can account for the difference in the results: weight assumed, geometry, and physical configuration, as there is great directional dependence.

Page 2 of 12 YR TBN Final Status Surveys Comments/Questions Email from Hickman to Carson dated June 14, 2006 TBN01-00 FSS Questions: (TBN-01-01; TBN-01-09 through TBN-01-17)

NRC Question #1: Section 5.2.4 Survey Results and the Table 10 results are in cpm, and the fixed-point measurement criteria or DCGL criteria is in dpm/100-cm2.

YR has not demonstrated that the criteria vixerel not exceeded.Yankee Response:

Yankee Response:

The fixed point measurement results for TBN-01-01 and TBN-01-09 through TBN-01-17 are provided in Table 8 in cpm and dpm/1 00 cm 2. Table 11 provides the results for fixed point measurements for survey units TBN-01-02 through TBN-0O-08, however, they are given only in units of cpm. Table 10 provides the survey design parameters for TBN-01-02 through 08 and sets the investigation level as 694 cpm, based upon a DCGLw of 434 cpm. Table 11 shows that mean of the fixed point measurement is generally less than half of the DCGLw and all measurements are below the DCGLw, thus the criteria were not exceeded and the survey units passed.Yankee provided the results in dpm/100cm 2 in fitture reports to facilitate comparison with the DCGL criteria NRC Questions

1. 2: Table 9 -Summary of ISOCS Scan results -provides the number of scans for each survey unit and the 'results' (action level exceeded) as"NO". Where is the ISOCS scan data -other than in the ISOC scan reports?Yankee Response:

Yankee agrees going forward that the data will be presented in Table 9 rather than "no. " In addition, Yankee will remove the term "statistical outlier" and use more clear terminology with the same intent.NRC Question #3: Vol. 1, Main Report: Table 5 DCGLw & DCGL-EMC for ISOCS (Co-60 and Cs-137. DCGLw for Co-60 is 6.3E+3 dpm/ 100cm 2 , and Cs-137 2.2E+4 dpm/100 cm 2).Co-60 AF= 7.3 (comparison used 1-m 2 EMC)Cs-137 AF= 7.3 (comparison used 1-m 2 EMC)Table 11 (Co-60 only. DCGL is 7.2E+3 dpm/100 cnl)Co-60 AF=16.67 (area of EMC not specified)

Yankee Response:

The AFs are correspond to the lm 2 area as it is the smallest area in the LTPfor which these factors are calculated (and are the maximum AFs calculated in the LTP). These lead to the highest MDCEAfc, which is conservative.

In addition, the values are used to establish "action levels" and not the actual a-priori DCGLEAfc.

The"action levels" trigger an investigation, at which time the actual a-posteriori DCGLEAfc is applied to the measurements.

Page 3 of 12 NRC Question #4. Vol. 1, Main Report, Table 10. Sample size is a function of relative shift (delta/sigma), and the relative shift should be a dimensionless number.LBGR & sigma are in different units. LBGR in dpm/100cm 2 and sigma is in cpm.Yankee Response:

Although the values in Table 10 are correct, the units were incorrect and should not have been listed. The values of the relative shift are correctly given as dimensionless in subsequent reports.NRC Question #5: Vol. 1, Main Report, Table 11. An Investigation level is listed for the HP OOC & SPA-3. Please provide an example calculation for the HP OOC scan MDC for alpha and beta radiation.

Table 11 lists HP IOOC IL as > 1.2E+4 or 7.2E+4 dpm/100 cm 2 & a statistical outlier.LTP page 5-39 indicates that the scan MDCs will be documented prior to performing the FSS.Yankee Response:

Section 3.0 of the Final Status Survey Plan (FSSP) provides the reference for the calculation of the scan MDCs. These are calculated and documented prior to the start of the Final Status Survey. The FSSPs are inchlded in the FSS report package. The calculation has been attached to these responses for ease of reference.

NRC Question #6: Vol. 1, Main Report, Section 4.1.3. Are compensatory measures needed for situations where a 4 cm2 "hot spot" was not detected by ISOCS? Table 5 indicates that the ISOCS Co-60 DCGLemc = 4.6E+4 dpm/100 cm 2 or assuming that activity is uniformly spread over a one-m2 area.Yankee Response:

In subsequent surveys the FSS Engineer reviewing the scan data was made aware of the possibility of very small areas of activity.

In cases where the results of the scan were less than unity but exhibited a concentration due solely to Co-60, additional investigations were made.NRC Question #7: Vol 3, Appendix C, YA-REPT-00-018-05.

Table 3 provide the one-meter squared surface DCGLw values (Co-60 is 6300 dpm/100 cm 2 adjusted to 8.73 mrem/y and DCGLECIC is 46,000 dpm/100 cm2 over 1-m 2).Yankee Response:

Correct. However, the DCGLEMc values provided in Table 3 were developed for the determination of investigation levels and would not be used in place of the actual a-posteriori DCGLEMc that would be calculated during the investigation.

These "investigation levels " are the values that trigger the additional investigation.

Page 4 of 12 NRC Question #8: Vol. 3, Appendix B, SUs TBN-01-10, -12. -13. -16, -17. The mean ambient background column is 20 entries and the sample data is 10 entries?Comments Yankee Response:

Appendix B to TBN-01 is Technical Report YA-REPT-00-015-04, which discusses instrument efficiencies and does not discuss the specific number offixed point measurements providedfor the different survey units in TBN-01. Attachment B to TBN-01 is the DQA for TBN-01 and includes the "Preliminary Data Review Form "for each of the survey units. This form lists 20 fixedpoint measurements for each of the units identified above (-10, -12, -13, -16, and -17). It also lists the gross activity concentrations for each of the 20 measurement IDs associated with the fixed point measurement in cohlmnar form. The entries in the cohlmn for "mean ambient background" are the mean background value determinedfor that survey unit and are not vahles for different background measurements.

This column is for the ease of the calculation of net counts and is not a one-to-one pairing offixed point and background measurements.

Page 5 of 12 YR WST Final Status Surveys Comments/Questions Email from Hickman to Carson dated June 14, 2006 WST-01-01 Survey Unit Background information:

Class I survey unit.(WST-01-01 is a single survey unit (WST-01-02) of the remnants of WST-01-01 which was the "Old PCA Storage Building" that has been demolished.

Reinforced concrete remnants of the potentially-contaminated-area (PCA) storage building within the RCA yard area.)NRC Question #1: Page 12, Ta ble 7. What are the ISOCS results? Suggest that this information be placed in the FSS.Yankee Response:

This information has been provided in subsequent FSS reports.NRC Question #2: Regarding the ISOCS scans locations map: It appears to be more then 97 ISOCs scans (114 data set )?Yankee Response:

The scans start with the scan number of 101 and end with a scan number of 196, indicating 96 scans were performed.

The report erroneously indicated 97. Attachment A to the FSS report for WST-01 inchldes a total of 96 ISOCS reports.NRC Question #3: Regarding the direct measurements locations map: The concrete structure in the upper portion had only one measurement and 12 ISOCS scans?Yankee Response:

The concrete structure has an unusual configuration, which necessitated additional ISOCS scans to provide 100% coverage.

As a result there was a great deal of overlap in the 1SOCS scans for the partial wall. The fixed measurements were determined by a triangular grid with a random start. In this case only one fixed point measurement fell on the structure.

NRC Question #4: Page 1, Section 1.3: Indicates that 97 ISOCS scans supplemented by hand-held survey meters and 24 fixed-point measurements were taken. Did the data variability indicate that adequate samples were taken?Yankee Response:

Although it is true that the retrospective standard deviation was larger that the prospective standard deviation, the original sample calculation called for a total-of l5fixed-point measurements to be taken. The FSS Engineer added 9 more fixed-point measurements to the plan, therefore increasing the power of the survey. The additional power added to the survey offset the slightly higher standard deviation by Page 6 of 12 "closing tip" the measurement grid, resulting in an adequate number of measurements being taken.NRC Question #5: ISOCS measurements were affected by radiation from the ISFSI.These areas were supplemented by SPA-3 scans. The SPA-3 scans identified two elevated soil areas in NOL-05-02.

Yankee Response:

That is correct. The two areas were scanned with a SPA-3, and subsequent remediation was performed in the two areas. One was a particle and the other was a small area containing distributed activity.

Subsequent surveys in the area adjacent to the ISFSI used the criteria that any plant related activity present was investigated (i.e. OOL-10-02)

Page 7 of 12 YR NOL Final Status Survey Units Comments/Questions NOL-01 has four (4) final status survey units Email from Hickman to Carson dated June 14, 2006 NRC Question #1: The NOL FSS documentation is much better written than TBNO1-00.

It includes the ISOCS data for the survey units (i.e., fraction -DCGL)Yankee Response:

No response necessary.

NRC Question #2: Tables 16 & 17 indicate that an investigation was done for samples no. 17. What were the results of the soil sample that prompted the investigation?

Yankee Response:

Table 16 indicates that an investigation was prompted by an 1SOCS scan. Table 17 shoes that the ISOCS scan results was 1.13 times unityfor the scan investigation level. Subsequent soil samples determining the boundaries of the elevated area and the average concentration of activity within this area are found in Table 17.Table 16 -Summary of ISOCS Scan Results for Survey Unit NOL-01-02.

Table 16 indicates to See Table 17, but Table 17 does not provide soil samples results in terms of pCi/g, but indicates that the sample results was 1.13 f-DCGL.Yankee Response:

Table 16 is a summary of ISOCS scan results which are reported in the fraction of unit of the investigation level. The valhe forf-DCGL for the 1SOCS scan for NOL-01-02-17-F-G was greater than I (1.13, as stated in the first row of Table 17), prompting an investigation via soil sample. The results of those investigatory soil samples are provided in the subsequent rows of Table 17 (NOL-01-02-032-F-1, etc.) in units ofpCi/g as indicated in cohmms 2, 3, and 4.Page 32. An Investigation was done at scan location 17. The elevated area was 2-m x 2.3-m. Four random soil samples were taken and an EMC calculation was made.The sum-of-fractions appears to be 0.25 (0.10 + 0.15), and the survey unit passes the criteria.Yankee Response:

Based upon the suggestion above, Yankee revised the way this data was presented in subsequent reports. Table 16 included the original sample vahle, and Table 17 provided the resample results. A conchlsion for that sample (for example, "the criteria was met') and the basis is being providedforfiuture reports, as well as the overall conclusion that "the criteria was met and the unit passed the FSS. " Page 8 of 12 NRC Question #3: What are the implications for YR survey methodologies by the fact that ORISE identified an elevated area of activity in NOL-01-03?

Additional remediation was required & table 23 presents the results of the post-remediation sampling.Yankee Response:

As a result of this, Yankee subsequently decided to utilize the same methodologyforpost-remediation/characterization samples, as that for FSS (i.e., ISOCS scanning);

therefore providing consistent instrument sensitivity by using consistent advanced technology in both surveys. In addition Yankee adopted a practice of using both ISOCs and SPA-3 scans for remediation/characterization surveys for robustness.

Are there any indicators (ISOCS scan results or otherwise) that may have indicated that elevated activity was in that survey unit?See Table 22 & Table 23.Yankee Response:

ISOCS scans did indicate activity present in the survey unit, albeit not above the investigation level, whereas SPA-3 scans did not indicate an elevated area.NRC Question #4: An investigation was done because of the ISOCS scan NOL-Ol-03-012 results. The data for this ISOCS scan is not provided in the Table 25.It would be appropriate to indicate the mean and variance/standard deviation of the mean for the data in Table 26.Yankee Response:

Table 25 illustrates "as left" results for the survey unit. Subsequent reports show all scan and sample results, as well as the mean and standard deviation for the data.NRC Question #5: Data Quality Assessment.

Are the data evaluations geared toward validating the assumptions (spatially independent concentrations, etc.)underlying the statistical tests used?Is the data uncertainty larger than the assumed sigma used to calculate the number of soil samples needed? YR indicates that the retrospective power curve indicated that the survey unit would pass the criteria for the samples taken.Yankee Response:

In all instances, the purpose of the Data Quality Assessment is to ensure that the sample data are representative of the parent. The risk associated with having a larger retrospective standard deviation is an increased Type H error (falsely failing the survey unit)..Page 9 of 12 YR Alternative Scenarios Potential Exposure to Hot Particles for the Anticipated Land Use Email Hickman to Carson Dated September 5, 2006 NRC Comment: YR has provided a dose calculation for the EDE for a 24-h exposure to a hot particle on the skin using the X. G. Xu dose factors in the technical literature.

This calculation may not adequately address the scope of potential exposure(s) that could arise for the public use of the decommissioned site. Other exposure pathways that should be considered include skin dose, inhalation dose, and ingestion dose from hot particles.

NRC has accepted the technical basis of the YR methodology for scan surveys in the final status surveys, but NRC in-process surveys indicated that some hot particles were not detected by the YR processes.

NRC requested in a July 12, 2006, letter that YR provide dose calculations to assist NRC assess the consequences of these hot particles.

NRC does not believe that the EDE calculation provided in its August 16, 2006, response adequately addresses the entire range of the potential exposures.

Dose Assessment Question: NRC requests that YR Identify (alternate) scenarios that may be reasonably anticipated for the planned land use, and that YR determine the resultant radiation doses from exposures to hot particles for members of the public using the decommissioned site.Yankee Response: The following two reports were provided to the NRC by Yankee on doses due to hot particles to resolve this question.YA-REPT-O0-016-06, "Discrete Particle Detection in the Performance of Final Status Surveys at Yankee Nuclear Power Station," included as an attachment to BYR 2006-71 datedAugust 16, 2006 and YA-REPT-00-018-06, "Estimated Doses form Inhalation, Ingestion, and Remote Exposure from Residual Discrete Particles at Yankee Nuclear Power Station Following License Termination, " included as an attachment to BYR 2006-94 dated November 16, 2006.Page 10 of 12 FSS Data Issues Email Hickman to Carson Dated September 5, 2006 TBN-01-02 through TBN-01-08 NRC Question #1 Systematic Survey Data Table 10 provides the survey design and indicates that all are Class 1 survey units.The survey design or Section 5.2.1.4 narrative indicates that 15 fixed-point samples will be taken in each survey unit. Table 13 provides the systematic survey data, but the results are in cpm. Table 11 provides the DCGL-w, DCGL-EMC and Investigation levels as dpm/100cn 2 units. The staff cannot determine if the DCGLs are exceeded or not.Yankee Response:

As discussed in the response to a similar question regarding TBN-01 dated June 14, 2006, all measurements are below the DCGL, the criteria were not exceeded and the survey units passed the final status survey. Yankee provided the results in dpm/lJOOcm 2 in fitture reports to facilitate comparison with the DCGL criteria NRC Question #2 Scan Survey Data: The staff cannot identify the scan survey data for these survey units in the FSS Report or attachments.

Yankee Response:

SPA-3 scan surveys in TBN-01 were performed in accordance with YNPS Procedure DP-8540 "Operation and Source Checks of Gamma Friskers, "in audible scan mode. This procedure instructs the technician to scan the survey unit in audible mode, and to investigate levels greater than background.

The procedure does not require the technician to log data. The supervisors record in their journal that no scan measurements iwere detected above background (If an investigation is performed, it is recorded in the fieldjournal.)

Yankee inchlded a statement in subsequent reports in Section 5.4 to indicate that the results of the SPA-3 scans indicate that no residual radioactivity exists above background NOL-01-01 and NISY]-12-01 The FSS Reports listed are both MARSSIM class I survey units, and require both systematic surveys and scan surveys.The staff cannot locate the scan survey data for NOL-01-01.

NOL-01 has four (4)survey units. ISOCS scan data or a data summary was identified for the other three (3) survey units.Page 11 of 12 The staff cannot locate scan survey data for NISY]-12-01 in the report or attachments.

NISYI-12 has a single survey unit.Yankee Response:

SPA-3 scan surveys in NOL-01 and NSY-12 were performed in.accordance with YNPS Procedure DP-8540 "Operation and Source Checks of Gamma Friskers, " in audible scan mode. This procedure instructs the technician to scan the survey unit in audible mode, and to investigate levels greater than background.

The procedure does not require the technician to log data. The supervisors record in their journal that no scan measurements were detected above background (If an investigation is performed, it is recorded in the fieldjournal.)

Yankee inchlded a statement in subsequent reports in Section 5.4 to indicate that the results of the SPA-3 scans indicate that no residual radioactivity exists above background.

Page 12 of 12 Table 2 MDC/MDCR Table for Building Surface Surveys -Scan MDCR(cp .38 (DP-8853)MD /c. V where: Rb = background count rate Inputs Calc'd Vals Detector area = 100 cm 2 L = Detector width (cm) = 10 cm =V = Scan speed = 2.00 in/s =3.94 in 304.80 cm/min 0.0328 min Ad~DCR MDQJD(fCGI_.MC)

= = s(f' /1 ,EAF DCGfL) (DP-8853)Cs-137 Co-60 (A/I O O) f'p ej=! 0.2413 es 0.50 DCGL 25000 f 0 AF= 1.6 0.2413 0.25 7200 1 1.6 A = 100 cm'p = 0.5 Rb I MDCR MDC (cpm)J (cpm) (fDCGLEMc) 50 53.9 0.110 60 59.0 0.120 70 63.7 0.130 80 68.1 0.139 90 72.3 0.147 100 76.2 0.155 110 79.9 0.163 120 83.5 0.170 130 86.9 0.177 140 90.1 0.183 150 93.3 0.190 160 96.4 0.196 170 99.3 0.202 180 102.2 0.208 190 105.0 0.214 200 107.7 0.219 210 110.4 0.225 220 113.0 0.230 230 115.5 0.235 240 118.0 0.240 250 120.5 0.245 260 122.8 0.250 270 125.2 0.255 280 127.5 0.259 290 129.7 0.264 300 132.0 0.269 310 134.1 0.273 320 136.3 0.277 330 138.4 0.282 340 140.5 0.286 350 142.5 0.290 360 144.6 0.294 370 146.6 0.298 (Table continued)

Rb MDCR MDC (cpm) (cpm) (fDCGLEMc) 380 148.5 0.302 390 150.5 0.306 400 152.4 0.310 410 154.3 0.314 420 156.1 0.318 430 158.0 0.322 440 159.8 0.325 450 161.6 0.329 460 163.4 0.333 470 165.2 0.336 480 166.9 0.340 490 168.6 0.343 500 170.4 0.347 510 172.1 0.350 520 173.7 0.354 530 175.4 0.357 540 177.0 0.360 (Tal continued)

Rb MDCR MDC (cpm) (cpm) (fDCGLEMC) 700 201.6 0.410 710 203.0 0.413 720 204.4 0.416 730 205.8 0.419 740 207.3 0.422 750 208.6 0.425 760 210.0 0.427 770 211.4 0.430 780 212.8 0.433 790 214.1 0.436 800 215.5 0.439 810 216.8 0.441 820 218.2 0.444 830 219.5 0.447 840 220.8 0.449 850 222.1 0.452 860 223.4 0.455 870 224.7 0.457 880 226.0 0.460 890 227.3 0.463 900 228.6 0.465 910 229.8 0.468 920 231.1 0.470 930 232.3 0.473 940 233.6 0.475 950 234.8 0.478 960 236.1 0.480 970 237.3 0.483 980 238.5 0.485 990 239.7 0.488 1000 240.9 0.490 550 178.7 0.364 560 180.3 0.367 570 181.9 0.370 580 183.5 0.373 590 185.1 0.377 600 186.6 0.380 610 188.2 0.383 620 189.7 0.386 630 191.2 0.389 640 192.7 0.392 650 194.2 0.395 660 195.7 0.398 670 197.2 0.401 680 198.7 0.404 690 200.1 0.407 92.21 73.2 0.149 Package Development\Tools\MDC-Bldg Surf.xls c:\temp\GWIOOOO1 .TMP Page 1 c*.\temp\GW)00001-.TMP Page 11 Mail Envelope Properties (45AFD60F.BAA

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Creation Date From: Created By: Written responses to FSS questions 01/18/2007 3:17:45 PM"Alice Carson" <acarson 1967 @comcast.net>

acarson 1967 @comcast.net Recipients nrc.gov OWGWPOO4.HQGWDOO1 JBH (John Hickman)nrc.gov TWGWPO04.HQGWDO01 THY (Thomas Youngblood)

CYAPCO.com VanNoordennen CC ('Gerard P. Van Noordennen')

Bourassa CC ('Joe Bourassa')

yankeerowe.com erickson CC Babineau CC ('Greg Babineau')

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