HBL-21-017, Clarification Regarding Final Status Survey Report for Humboldt Bay Power Plant

Clarification Regarding Final Status Survey Report for Humboldt Bay Power Plant

ML21301A143
Person / Time
Site:	Humboldt Bay
Issue date:	10/28/2021
From:	Zawalick M Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards
References
HBL-21-017
Download: ML21301A143 (10)

Text

Maureen R. Zawalick Vice President Generation Business and Technical Services Diablo Canyon Power Plant Mail code 104/6/608 P.O. Box 56 Avila Beach, CA 93424 805.545.4242 Internal: 691.4242 PG&E Letter HBL-21-017 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Humboldt Bay Power Plant, Unit 3 Docket No. 50-133, DPR-7 Clarification Regarding Final Status Survey Report for Humboldt Bay Power Plant

Reference:

1. PG&E Letter HBL-21-010, Final Status Survey Reports for the Humboldt Bay Power Plant, dated June 8, 2021 (ML21160A224)

2. Email from NRC Project Manager, Amy Snyder, Humboldt Bay Unit 3 Clarification Question, dated October 26, 2021

3. PG&E Letter HBL-21-011, Final Status Survey Report for Humboldt Bay Power Plant, dated July 13, 2021 (ML21194A441)

Dear Commissioners and Staff:

Pacific Gas and Electric Company (PG&E) is providing this letter to clarify three different items associated with NRC review of various Humboldt Bay Power Plant (HBPP) Final Status Survey (FSS) Reports.

In Reference 1, PG&E submitted three FSS Reports for HBPP. Per a clarification phone call with the NRC on October 21, 2021, PG&E is clarifying information included in of Reference 1. Enclosure 3 of Reference 1 described an instance where investigative sample OOL01-03-027-F-I, collected during a walkover survey, indicated elevated Cesium-137 at 2.68E+01 picocuries per gram. The elevated reading was bounded and a pre-sample one minute static count confirmed its location. An investigation sample was taken and a post sample one minute static count survey was performed. The post sample survey result was consistent with survey area background levels. This process ensured the area was remediated by sampling. An in situ object characterization system shot over the investigative sample location was taken as additional verification that the as-left location was less than the derived investigation levels specified in the FSS Plan.

Per a clarification phone call with the NRC on October 21, 2021, PG&E is following up to provide additional clarifying information regarding the process for radionuclides of concern (ROCs) in the FSS Reports (FSSRs). For any specific survey unit, if any ROCs were neither deselected nor reported (e.g., Nb-94, Eu-152, Eu-154, Np-237, and Am-m PacHic Gas and Electric Company*

Document Control Desk PG&E Letter HBL-21-017 Page 2 241 are typically not reported in most of the FSSRs), then those ROCs were not detected at concentrations above their respective minimum detectable concentration and/or were of such low concentration that it had, on average, negligible potential dose impact. As a result, those ROCs were not reported for that particular survey unit.

In Reference 2, NRC requested that PG&E provide the analytical results associated with the composite sample of the Waste Management Facility Pad described in Reference 3. The Enclosure, Gamma Spectrum Analysis, provides the analytical results of the Waste Management Facility Pad composite sample associated with survey unit OOL10-24-FSR.

PG&E makes no new or revised regulatory commitments (as defined in NEI 99-04) in this letter.

If you have any questions or require additional information, please contact Mr. Philippe Soenen at (805) 459-3701.

Sincerely, Maureen R. Zawalick Vice President Generation, Business and Technical Services Enclosure cc:

Humboldt Distribution cc/enc: Scott A. Morris, NRC Region IV Administrator Amy M. Snyder, NRC Reactor Decommissioning Branch Project Manager

PG&E Letter HBL-21-017 Enclosure Gamma Spectrum Analysis FSS-2489, OOL10-24-002-M-C Composite

GAMM A S P E C T R U M A N A L Y S I S Report Generated On Sample Identification Sample Title Sample I nformation Sample Type Sample Geometry Peak Loc at e Threshold Peak Locate Range (in channels)

Peak Area Range (in channel s)

Identification Energy Tolerance Sample Size Sample Taken On Acquisition Started Live Time Real Time Dead Time 10/30/2 019 1:01:18 PM FSS-2489 OOLl0 0 02 - M-C Composite Media 3.00 100 -

4096 100 -

4096

1. 000 keV 3.770E+002 g 10/30/2019 11:05:00 AM 10/30/2019 11 :49:05 AM 3600.0 seconds 3607. 6 seconds 0~21 %

Energy Calibration Used Done On Efficiency Calibration Used Done On Efficiency ID 12/4/2015 6/11/2019 500ml BeakerDl.6 Performed by,6;. d-,,,v--u..

Date 10 - lo - (~

Alderman, Anderson, Burrell, Eckhardt,tephens Reviewed by C AlderJ.lliiD--? Anderson Date H* -3o-lf i

Peak Locate Analysis Report 10/30/2019 1:01:19 PM Page 2

P E A K L O C A T E R E P O R T Detector Name:

DET0848 Sample

Title:

OOLl0-24-002-M-C Composite Peak Locate Performed on:

10/30/2019 1:01:18 PM Peak Locate From Channel:

100 Peak Locate To Channel:

4096 Peak Search Sensitivity:

3.0 0 Peak Centroid Centroid Energy Peak No.

Channel Uncertainty (keV)

Significance 1

127.13 0.4903 63. 32 3.62 2

150.12 0.3864 74.78 4.08 3

154.80 0.3779 77.10 5.57 4

477.48 0.2658 238.66 7.29 5

484. 67 0.4191 242.16 3.79 6

590. 55 0.3364 295. 25 4.87 7

704.13 0.2417 352.0 8 8.49 8

955.22 0.1017 47 7.7 2 45.59 9

1166.35 0.2938 583.3 3 5.19 10 1218.78 0.2373 609.46 7.91 11 1322.95 0.3097 661.62 4.86 12 1536.84 0.4108 76 8.60 3.17 13 1822.59 0.3141 911.42 3.90 14 1938.27 0.3352 969.30 3.36 15 2922.61 0.1823 1461.26 9.56

? = Adjacent peak noted Errors quoted at 2.000 sigma

Peak Analysis Report 10/30/2019 1:01:19 PM Page 3

P E A K A N A L Y S I S R E P O R T Detector Name:

DET0848 Sample

Title:

OOLl0 002-M-C Composite Peak Analysis Performed on:

10/30/2019 1:01:18 PM Peak Analysis From Channel:

100 Peak Analysis To Channel:

4096 Peak ROI ROI No. start end F

1 M

2 m

3 M

4 m

5 F

6 F

7 F

8 F

9 F

10 F

11 F

12 F

13 F

14 F

15 123-146-146 -

130 158 158 473-489 473-489 586-595 699-709 949-960 1162-1170 1214-1224 1319-1328 1534-1540 1817-182 7 1934-1943 2917-2929 Peak Energy centroid (keV) 127.22 150.12 154.75 477.48 484.48 590. 56 704. 14 955. 26 1166. 42 1218. 66 1322. 96 1536. 90 1822. 58 1938.36 2922. 75 63. 32 74.78 77.10 238.66 242.16 295. 25 352. 08 477.72 583. 33 609. 46 661. 62 768.60 91 1. 42 969. 30 1461. 26 M

First peak in a mul tiplet region m

Other peak in a multiplet region F = Fitted singlet Errors quoted at 2.000 sigma FWHM Net Peak Net Area (keV)

Area Uncert.

0. 68 6.89E+001 0.90 l. 44E+002 0.90 l. 56E+002 1.17 3.35E+002 1.17 l.11E+002 1.07 1. 31E+002

1. 26

l. 26

l. 36

l. 34 1.08 0. 99 1. 44 1. 47 1.89 2. 84E+002 6. 39E+003 l. 02E+002 l. 98E+002 5. 29E+001 l. 91E+001 5.53E+001 4. 13E+00 1 3.88E+002 39.98 37.76 40.06 45.02 29. 56 34.92 37.42 154.74 20.2 7 28. 11 17. 13 11.49 16.48 14. 98 38. 43 Continuum Counts 3.25E+002 3.42E+002 3.41E+002 2.66E+002 2.54E+002 3. 18E+002 1.68E+002 l. 20E+002 2. 20E+001 4. 03E+001 3. 93E+001 1.83E+001 2. 74E+001 2. 67E+001 l. 81E+001

Interference Corrected Activity Report 10/30/2019 1:01:19 PM Page 4

N U C L I D E I D E N T I F I C A T I O N R E P O R T Sample

Title:

OOLl0-24-002-M-C Composite Nuclide Library Used: C:\\GENI E2K\\CAMFILES\\HBPP.NLB IDENTIFIED NUCLIDES Nuclide Name Bi - xRay Pb-xRay Be-7 K-40 Cs-137 Tl - 208 Pb-212 Bi - 214 Pb-214 Ac - 228 Id Confidence 0. 554 0.437 0. 997 0.968 1. 000 0. 691 0. 894 0.465 0. 997 0.559 Energy (keV) 77.11*

87.20 72.80 74.97*

477.59*

1460.81*

661.65*

277. 35 583. 14*

860. 37 238.63*

300. 09 609. 31*

1120. 29 1764. 49 241. 98

• 295. 21*

351. 92*

338. 32 91 1.07*

969.11*

Yield

( % )

100.00 36. 00 55.00 100. 00 10. 42 10. 67 85. 12 6. 80 84.20 12. 46 44. 60 3. 41 46.30 15.10 15. 80 7. 49 1 9. 20 37. 20 11.40 27.7 0 16. 60 Activity (pCi/g 6.02527E - 002 5.81523E-002 3.75168E+001 4. 83111E+000 4.75849E - 002 Activity Uncertainty 1.95979E - 002 1. 91561E-002 4.75672E+000 6.15037E-001 1.64414E - 002 8.53015E-002 l. 97721E-002 2. 81488E - 001 5. 88232E - 002 3.09928E - 001 5. 75907E-002 5. 63247E-00 1 1. 74448E - 001 2. 96 758E - 001 9.20350E-002 3. 75093E-001 7.47826E-002 l.90279E-001 5. 93854E-002 2. 47489E - 001 9. 21869E-002

• =Energy line found in the spectrum.

@=Energy line not used for Weighted Mean Activity Energy Toler ance :

1. 000 keV Nuclide conf i dence index threshold 0. 30 Errors quoted at 2. 000 sigma

Interference Corrected Activity Report 10/30/2019 1:01:19 PM Page 5

I N T E R F E R E N C E C O R R E C T E D R E P O R T Nuclide Wt mean Wt mean Nuclide Id Activity Activity Name Confidence (pCi/g Uncertainty Bi-xRay 0.554 6.025274E - 002 1.959792E-002 Pb-xRay 0.437 5.815228E-002 l.915606E-002

.,,,- Be-7,. ~*"'"l'""'c.. 0.997 3.751678E+001 4.756716E+000 K-40 0.968 4.831114E+000 6.150366E-00 1

....-ts - 137 1.000 4.758488E-002 1.644141E-002 Tl-208 0.691 8.530150E-002

1. 97721 3E-002 Pb-2 12 0.894 2.814882E-001 5.882321E-002 Bi-214 0.465 3.099282E-001 5.759072E-002 Pb - 2 14 0.997 3.657965E-001 5.507068E-002 Ac-228 0.559 2. 070573E-001 4.992354E-002

?

nuc l ide is part of an undetermined solution X

nuclide rejected by the interference analysis nuclide contains energy lines not used in Weighted Mean Activity Errors quoted at 2.000 sigma

Interference Corrected Activity Report 10/30/2019 1:01:19 PM Page 6

UN I D E N T I F I E D PE AK S Peak Locate Performac:Lon * ~~J~D. t.J_o_,l2-0l9 J

• QL;,_J._.,_R_,_,P'-'M F

F Peak Locate From Channel :

Peak Locate To Channel :

Peak Energy Peak Size in No.

(keV)

Counts per Second 1

63. 32 1.9136E-002 12 768.60 5.3160E - 003 M = First peak in a multiplet region m = Other peak in a multiplet region F

Fitted singlet Errors quoted at 2. 000 sigma 100 4096 Peak CPS Peak Tol.

% Uncertainty Type Nuclide 58.03 Tol.

II rt Th-234 /!.):::- >

60.04

(:;;*.:u~

/0 __ J u -*1 '\\

Nuclide MDA Report 10/30/2019 1: 01:19 PM Page 7

N U C L I D E MD A R E P O R T

+

+

+

Detector Name:

Sample Geometry :

Sample Tit l e :

Nuclide Library Used:

Nuclide Name K-4 0 Co-60 Nb-94 Ag-108m Cs-134 Cs - 137 Eu-152 Eu-154 Eu-155 Ac - 228 Th-234 U-235 Np-237 U-238 Am-241 Energy (keV) 1460. 81"k 1173.22 1332.49 702. 63 871.10 433.93 614.37 722. 95 569.31 604. 70 795. 84 661. 65*

121.78 244.69 344. 27 778. 89 964. 01 1085. 78 1112.02 1407.95 123. 07 723. 30 873.19 996.32 1004. 76 1274. 45 105.31 338.32 911.0 7*

969.11

• 63.29 92. 59 143. 76 185.72 311.98 1001.03 59.54 DET0848 OOLl0-24-002-M-C Composite C:\\GENIE2K\\CAMFILES\\HBPP.NLB Yield

( % )

Line MDA (pCi/g Nuclide MDA Activity

) ( pCi/g

) (pCi/g Dec. Level

) (pCi/g 10.67 3.18E -001 3.18E-001 4.83E+000

l. 42E-001 100.00 4.12E-002 3.66E-002 1.43E-002 1.91E-002 100.00 3.66E - 002 1.96E-002 l. 66E-002 100.00 2.87E - 002 2.87E-002 -1. 22E - 002 l.33E-00 2 100.00 3.35E-002 2.20E-002 l.55E-002 89.90 3.75E-002 3.75E-002 -2.71E-002 1.79E-002 90. 40 5. 06E-002 90. 50 3.99E-002

-3.22E-003 2.42E-002

-3.13E-002 1.87E-002 15.43 l. 91E-001 3.56E-002 4. 27E-002 8. 96E-002 97. 60 85. 40 85.12 28.40 4.45E - 002 3. 56E-002 3. 33E-002 l. 09E-001 7. 49 5. 27E-001 26.50 1.45E-001 12.74 2. 56E-001 14. 40 3. 09E - 001 10.00 3. 57E-001 13. 30 2.61E-001 20.7 0 l. 76E-001

-9. 19E-003 1. l0E-002 3.33E - 002 4.76E - 002 l.09E-001 8.0 lE-003 2. 12E-002 l.64E-002 1.54E-002 5.33E -002 l. 53E-003 2. 57E-001 3. 48E-002 7. 0lE-002 1.58E-0 01 1.19E-001

-4.27E -002 1. 45E - 001

-3.49E - 002 1.64E-001

-2.94E-001 1.20E-001 7.34E - 002 7.96E - 002 40.5 0 7.62E - 002 7.62E-002 1.71E- 002 3.71E-002 19.70 11. 50 10.30 17.90 35. 50 1. 92E-001 2. 79E-001 3. 16E-00 1 2. l0E-001 9.85E - 002 2. 64E-002 6.14E-002

-6.23E-002 1.17E - 001

- 1. 03E - 00 1 9.02E-002 1. 28E-001 1.45E-00 1 9. 74E - 002 4. 46E - 002 20.70 1.29E-001 1.29E - 001 -2. 88E-004 6.26E-002 11.40 3. 57E-001 l.09E-001 2.80E - 001 1.73E-001 27.70 16.60 3. 80 5.41 10.50 54.00 38.60 0.84 35.90 1.09E-001 l. 83E-001 1. 52E+000 6. 54E-001 2.79E-001 7. 19E-002 1. 09E-001 4. 35E+000 l.7 1E-001 1.90E-001 2. 47E-001 6. 54E-001 l.SlE+000 6. 94E - 00 1 7.19E-002 -1. 52E - 001 6.49E-002 1.09E- 001 l.31E - 001 4. 35E+000 l. 53E+000 1.71E-001 - 1. 64E-001 4.99E-002 8. 34E-002 7. 40E-001 3.19E-001 l. 36E-001 3.51E-002 5. 28E-002 2. 0lE+000 8.33E-002

+

Nuclide identified during the nuclide identification

• = Energy line found in the spectrum

>=Calcul ated MDA i s zero due to zero counts in the region, or the region is outside the spectrum, or MDA 'has not been calculated Half-life too short to be able to perform the decay correction