ML091040715

Annual Radioactive Effluent Release Report for 2008

ML091040715
Person / Time
Site:	Humboldt Bay
Issue date:	12/31/2008
From:	Pacific Gas & Electric Co
To:	NRC/FSME
References
HBL-09-003
Download: ML091040715 (20)

Text

Enclosure 1 PG&E Letter HBL-09-003 HUMBOLDT BAY POWER PLANT UNIT 3 ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT January 1 through December 31, 2008

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE OF CONTENTS INTRODUCTION ............................................................................... 2

1. SUPPLEMENTAL INFORMATION.................................................... 3 II. GASEOUS AND LIQUID EFFLUENTS ............................................... 7 Table 1 - Gaseous Effluents - Summation of All Releases.......................... 8 Table 2A - Gaseous Effluents - Elevated Release - Nuclides Released............ 9 Table 2B3 - Gaseous Effluents - Ground-Level Releases - Nuclides Released .. 10 Table 3 - Liquid Effluents - Summation of All Releases ............................ 11 Table 4 - Liquid Effluents - Nuclides Released ...................................... 12 Ill. SOLID RADIOACTIVE WASTE....................................................... 13 Table 5 - Solid Waste and Irradiated Fuel Shipments ................................ 14 IV. RADIOLOGICAL IMPACT ON MAN .................................................. 17 Table 6 - Radiation Dose for Maximally Exposed Individuals...................... 18 V. CHANGES TO THE OFFSITE DOSE CALCULATION MANUAL (ODCM)........ 19 VI. CHANGES TO THE PROCESS CONTROL PROGRAM (PCP)................... 19 VII. CHANGES TO RADIOACTIVE WASTE TREATMENT SYSTEMS ............... 19 VIII. INOPERABLE EFFLUENT MONITORING INSTRUMENTATION................. 19 I

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 INTRODUCTION This report summarizes gaseous and liquid radioactive effluent releases from Humboldt Bay Power Plant Unit 3 for the four quarters of 2008. The report includes calculated potential radiation doses from these radioactive effluents and a comparison with the numerical guidelines of 10 CFR 50, Appendix I, as well as a summary of "

shipments of solid radioactive waste. The concentrations of plant effluent releases during the reporting period were well below Offsite Dose Calculation Manual (ODCM) limits.

The information is reported as required by Section 3.7.3 of the Humboldt Bay Power Plant Unit 3 SAFSTOR Quality Assurance Plan and Section 4:.2 of the ODCM, and it is presented in the general format of Regulatory Guide 1.21, Appendix B (except for the topics identified below).

Meteorology The meteorological data logging system was removed from service in 1967 so the

'information specified by Regulatory Guide 1.21, Appendix B,,Section F, is not available. Previous Humboldt Bay Power Plant Annual Radioactive Effluent Release Reports summarized the cumulative joint frequency distribution of wind speed, direction, and atmospheric stability for the period April 1962 through June 1967, when the meteorological data logging system was in service.

Short-lived Nuclides The Unit was last operated on July 2, 1976. Due to the long decay time since operation, short-lived radionuclides are neither expected nor reported. This includes lodines and noble gases other than Krypton-85.

Air Particulate Filter Composites - Sr-90 Air particulate sample filters are combined for approximately monthly intervals and analyzed off-site for Sr-90.

Air Particulate Filter Composites - Gross Alpha Each weekly sample filter is individually counted for gross alpha activity, rather than analyzing a monthly composite of the filters, as described in Regulatory Guide 1.21.

Gaseous Effluents - Tritium Tritium releases during plant operation were less than detection levels. Since the plant was permanently shutdown in 1976, current tritium release levels are less than the release levels that occurred during plant operations. Therefore, no tritium samples were collected during this reporting period.-

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 Liquid Effluents - Sr-90 Batch releases may be analyzed individually, or composited and analyzed monthly, rather than analyzed as a quarterly composite as described in Regulatory Guide 1.21.

Average Energy For HBPP, calculations for the average energy of gaseous releases of fission and activation gases are not required to be performed or reported.

I. SUPPLEMENTAL INFORMATION A. Regulatory Limits

1. Gaseous Effluents

a. Noble Gas Release Rate Limit The radioactive noble gas release rate limit is based on concentration limits from 10 CFR 20, divided by an annual average dispersion factor for the sector with the least favorable atmospheric dispersion.

The applicable annual average dispersion factor is 1.OE-5 seconds per cubic meter.

b. Iodine Release Rate Limit Due to the long decay time since the Unit was shutdown, the license does not define an iodine release rate limit.

c. Particulate Release Rate Limit The radioactive particulate release rate limit is based on concentration limits from 10 CFR 20, divided by an annual average dispersion factor for the sector with the least favorable atmospheric dispersion. The applicable annual average dispersion factors for elevated releases and for ground-level releases are 1.OE-5 and 6.59E-3 seconds per cubic meter, respectively. The radionuclide mixture was determined to be 65%

Cs-137, 9% Co-60, 4% Sr-90, 5% Fe-55, 11% Ni-63 and 6% Pu-241.

When both elevated and ground-level releases occur, the "percent of applicable limit" in Table 1 is the sum of the values for "percent of applicable limit" for each of the release paths.

2. Liquid Effluents

a. Concentration Limit 3

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 Concentration limits for liquid effluent radioactivity released to Humboldt Bay are taken from 10 CFR 20.

B. Maximum Permissible Concentrations

1. Gaseous Effluents Maximum Permissible Concentrations for gaseous effluents are taken from 10 CFR 20, Appendix B, Table 2, Column 1.

2. Liquid Effluents Maximum Permissible Concentrations for liquid effluents taken from 10 CFR 20, Appendix B, Table 2, Column 2.

C. Measurements and Approximations of Total Radioactivity

1. Gaseous Effluents - Elevated Release

a. Fission and Activation Gases All ventilation and system vents are routed to the Unit 3 stack. A continuous monitor equipped with a beta scintillator, with its response calibrated for Kr-85, monitors the gaseous activity released from the stack.

The "less than" value reported for Kr-85 is based on the estimated sensitivity of the stack Kr-85 monitor.

The estimated sensitivity of the stack Kr-85 monitor permits detection of Kr-85 at approximately 50% of the applicable Lower Limits Of Detection (LLD) presented in the ODCM.

b. lodines Due to the long decay time since operation (shutdown July 2, 1976),

no detectable releases of radioactive lodines can be expected.

Therefore, neither, the Technical Specifications nor the ODCM require that these radionuclides be monitored.

c. Particulates Radioactive particulates released from the plant stack are monitored by continuous sample collection on particulate filters. Filter papers are removed from the stack sampling system weekly, and are analyzed for the concentration of gamma-emitting nuclides (intrinsic germanium detector). All statistically significant gamma peaks are identified.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 After decaying at least 7 days, the filters are analyzed for gross alpha radioactivity (scintillation counter).

Filters are composited monthly and analyzed monthly for Strontium-90 (the only radioactive Strontium present) and Americium-241 by alpha spectroscopy. The monthly composite results are averaged together to produce the quarterlycomposite result.

The estimated error of the reported particulate release values is based on uncertainty in sample flow rate, stack flow rate, detector calibration, and typical sample counting statistics.

The Minimum Detectable Activity (MDA) for all particulate filter samples was less than the applicable LLD presented in the ODCM.

Samples are assigned to calendar quarters as of the termination of the sample period. The amount of activity reported for a calendar quarter is the activity for the combined sample time, multiplied by the ratio of the length of the calendar quarter to the sample period.

2. Gaseous Effluents - Ground-level Release

a. Fission and Activation Gases All ventilation and system vents were routed to the Unit 3 stack during the report period. Refer to the discussion for elevated releases.

b. lodines All ventilation and system vents were routed to the Unit 3 stack during the report period. Refer to the discussion for elevated releases.

c. Particulates All ventilation and system vents were routed to the Unit 3 stack during the report period. Refer to the discussion for elevated releases.

3. Liquid Effluents 5

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008

a. Batch Releases Water from contaminated plant systems was collected, filtered, treated with Cesium-specific ion-exchange media, and analyzed before discharge (on a batch basis) through the liquid radwaste process monitor. Analysis of weekly composite samples from the plant effluent canal did not detect any additional release of radioactive liquids during the report period.

Samples of liquid waste batches were analyzed for the concentration of gamma-emitting nuclides (intrinsic germanium detector). All statistically important peaks were identified. All batches were analyzed for radioactive strontium (Sr-90), gross alpha, Ni-,63 and tritium.

The error of the reported release values is estimated based on uncertainty in sample volume, batch volume, detector calibration, and typical sample counting statistics.

The MDA for all batch samples was less than the applicable LLD presented in the ODCM.

b. Continuous Releases There were no continuous liquid effluent releases during this report period.

D. Batch Release Statistics

1. Liquid

a. Num ber of batch releases .................................................. 5

b. Total time period for batch releases ................. 8.85E2 minutes

c. Maximum time period for a batch release ...... 2.41 E2 minutes

d. Average time period for a batch release ......... 1.77E2 minutes

e. Minimum time period for a batch release ....... 1.53E2 minutes

2. Gaseous a: Number of batch releases ......................... 0

b. Total time period for batch releases ................. N/A 6

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008

c. Maximum time period for a batch release .......................... N/A

d. Average time period for a batch release ............................ N/A

e. Minimum time period for a batch release ........................... N/A E. Abnormal Release Statistics

1. Liquid

a. Num ber of abnormal releases ............................................ 0

b. Total activity released ....................................................... N/A

2. Gaseous

a. Num ber of abnorm al releases .............................................. 0

b. Total activity released ....................................................... N/A I1. GASEOUS AND LIQUID EFFLUENTS A. Gaseous Effluents Table 1 summarizes the total quantities of radioactive gaseous effluents.

Table 2A presents the quantities of each of the nuclides deter'mined to be released from the stack (elevated release point). Table 2B presents the quantities of each of the nuclides determined to be released by other routes (ground level release points).

B. Liquid Effluents Table 3 summarizes the total quantities of radioactive liquid effluents. Table 4 presents the quantities of each of the nuclides determined to be released.

The quantity of radionuclides released in 2008 is similar to 2007, but higher than in previous years. The increase in the activity was due to the breach in the resin transfer line from the spent fuel pool demineralizer to the resin disposal tank. This breach resulted in resin being spilled into the offgas tunnel and rainwater in-leakage to the tunnel transporting the contamination into the liquid radioactive waste system. There was no unmonitored release of radioactivity from this incident.

The higher quantities of radionuclides discharged did not exceed the requirements of the ODCM.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 1 GASEOUS EFFLUENTS - SUMMATION OF ALL RELEASES Units First Second Third Fourth IEst. Total.

Quarter Quarter Quarter QuarterI Error, %I A. Fission & Activation Gases

1. Total release Ci <5.83E1 <5.83E1 <5.83E1 <5.83E1 3.20E1:]

2. Average release rate PCi/sec <7.41E0 <7.41E0 <7.41E0 <7.41E0

3. Percent of applicable limit  %. <1.06E-2 <1.06E-2 <1.06E-2 <1.06E-2

4. Applicable limit p.Ci/cc 7.OOE-7 7.00E-7 7.OOE-7 7.OOE-7 B. Particulates .

[1. Total release I Ci I<3.68E-06 <3.71E-06 <3.35E-061 <3.54E-061 3.60E1

2. Average release rate 4Ci/sec I <4.39E-071 <4.72E-071 <4.26E-071 <4.51 E-07

3. Percent of applicable limit  % <3.55E-06 <3.81 E-06 <3.44E-06 <3.64E-06

4. Applicable limit gCi/cc 1.24E-10 1.24E-10 1.24E-10 1.24E-10

5. Gross alpha radioactivity Ci <1.09E-07 <1.22E-07 <1.05E-07 <7.92-08 Note: The < symbol used in this table means that a majority of the measurements contributing to the result were less than the Minimum Detectable Activity (MDA) for the analyses. Data for individual nuclides combines detected and non-detected results as if all values were detected. The < symbol is applied if less than 50% of the combined value is made up of detected results. When combining detected and non-detected results for different nuclides (e.g. activity totals of multiple nuclides),

values with the < symbol are ignored (i.e. treated as zero). When combining non-detected results for different nuclides (e.g. activity totals of multiple nuclides, when none were detected), all values with the < symbol are used.

If the total release for a period is determined to be a "less than" value, the limits are based on analytical results obtained in November, 2005, where the mixture was determined to be 84% Cs-1 37, 11% Co-60 and 5% Sr-90.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 2A GASEOUS EFFLUENTS - ELEVATED RELEASE - NUCLIDES RELEASED

'_ Continuous Mode Nuclides Released Unit First [ Secondd Third Fourth Quarter Quarter Quarter Quarter

1. Fission Gasses _

Krypton-85 Ci <5.83E1 <5.83E1 <5.83E1 <5.83E1 Total for period Ci <5.83E1 <5.83E1 <5.83E1 <5.83E1

2. Particulates Cobalt-60 Ci <1.07E-6 <6.84E-7 <9.48E-7 <7.64E-7 Strontium-90 Ci <2.06E-07 <8.12E-07 <2.36E-07 <5.40E-7 Cesium-137 Ci <6.91E-07 <7.03E-07 <5.80E-07 <<6.84E-07 Am-241 Ci <1.71E-06 <1.51E-06 <1.59E-06 <1.56E-06 Total for period Ci <3.68E-06 <3.71E-06 <3.35E-06 <3.54E-06 Note: The < symbol used in this table means that a majority of the measurements contributing to the result were less than the Minimum Detectable Actiyity (MDA) for the analyses. Data for individual nuclides combines detected and non-detected results as if all values were detected, but the < symbol is applied if less than 50% of the combined value is made up of detected results. When combining detected and non-detected results for different nuclides (e.g. activity totals of multiple nuclides), values with the < symbol are ignored (i.e. treated as zero). When combining non-detected results for different nuclides (e.g. activity totals of multiple nuclides, when none were detected), all values with the <

symbol are used.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE2B GASEOUS EFFLUENTS - GROUND-LEVEL RELEASES NUCLIDES RELEASED Continuous Mode Nuclides Released Unit First Second Third Fourth Quarter Quarter Quarter Quarter

1. Fission Gasses __

Krypton-85 Ci N/A N/A N/A N/A Total for period Ci N/A N/A N/A N/A

2. Particulates Cobalt-60 Ci N/A N/A N/A N/A Strontium-90 Ci N/A N/A N/A N/A Cesium-1 37 Ci N/A N/A N/A N/A Americium-241 Ci N/A N/A N/A N/A Total for period Ci N/A N/A N/A N/A Note: N/A - There were no ground level gaseous effluents during the report period.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 3 LIQUID EFFLUENTS - SUMMATION OF ALL RELEASES First Second Third Fourth Est. Total Units Quarter Quarter Quarter Quarter Error, %

A. Fission & Activation Products

1. Total release (not including tritium, gases, alpha) Ci 2.70E-4 1.08E-04 0 1.36E-3 1.OEl

2. Average diluted pCi/ml 1.12E-11 4.72E-12 0 5.64E-11 concentration

3. Percent of applicable limit  % 1.71 E-03 7.86E-4 0 1.1 OE-2

4. Applicable limit pCi/ml 6.52E-7 6.01 E-07 0 5.14E-7 B. Tritium

1. Total release Ci 6.64E-5 2.67E-5 0 2.85E-3 1.50E1 ]

2. Average diluted ViCi/ml 2.74E-12 1.16E-12 0 1.18E-10 concentration

3. Percent of applicable limit  % 2.74E-7 1.1 6E-7 0 1.1 8E-5

4. Applicable limit giCi/ml 1.OOE-03 1.OOE-03 0 1.OOE-03 C. Gross Alpha Radioactivity

1. Total release Ci 5.73E-7 <2.40E-8 0, <1.32E-7 1.OOE1I D. Volume of waste released Liters 5.05E+04 2.40E+04 0 5.05+04 3.OOEO (prior to dilution)

E. Volume of dilution water Liters 2.42E+10 2.30E+10 N/A 2.41E+10 1.50E Notes:The < symbol used in this table means that a majority of the measurements contributing to the result were less than the Minimum Detectable Activity (MDA) for the analyses. Data for individual nuclides combines detected and non-detected, results as if all values were detected, but the < symbol is applied if less than 50% of the combined value is made up of detected results. When combining detected and non-detected results for different nuclides (e.g. activity totals of multiple nuclides),

values with the < symbol are ignored (i.e. treated as zero).

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 4 LIQUID EFFLUENTS - NUCLIDES RELEASED Batch Mode Nuclides Released Unit First Second Third Fourth Quarter Quarter Quarter Quarter Strontium-90 Ci 1.44E-4 7.21 E-5 0 1.29E-3 Cesium-137 Ci 1.26E-04 3.63E-5 0 7.05E-5 Cobalt-60 Ci <1.25E-6 <8.46E-7 0 1.04E-6 Americium-241 Ci <4.70E-6 <4.21E-6 0. <3.58E-6 Nickel-63 Ci 2.46E-5 1.17E-5 0 1.67E-5 Tritium Ci 6.64E-5 2.67E-5 0 2.85E-3 Neptunium -239 Ci 0 0 0 1.96E-6 Alpha Emitters Ci 5.73E-7 <2.40E-8 0 <1.32E-7 Total for period Ci 3.62E-4 1.47E-04 0 4.23E-3

___Continuous Mode Nuclides Released Unit First Second Third Fourth Quarter Quarter Quarter Quarter Strontium-90 Ci N/A N/A N/A N/A Cesium-1 37 Ci N/A N/A N/A N/A Cobalt-60 Ci N/A N/A N/A N/A Americium-241 Ci N/A N/A N/A N/A Total for period Ci N/A N/A N/A N/A Notes: The < symbol used in this table means that a majority of the measurements contributing to the result were less than the Minimum Detectable Activity (MDA) for the analyses. Data for individual nuclides combines detected and non-detected results as if all values were detected, but the < symbol is applied if less than 50% of the combined value is made up of detected results. When combining detected and non-detected results for different nuclides (e.g. activity totals of multiple nuclides), values with the < symbol are ignored (i.e. treated as zero).

N/A - There were no continuous liquid effluent releases during this report period.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 III. SOLID RADIOACTIVE WASTE Table 5 summarizes the disposal of solid radioactive waste and irradiated fuel shipments made during the report period.

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HUMBOLDT BAY POWER PLANT' ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 5 SOLID WASTE AND IRRADIATED FUEL SHIPMENTS A. Solid Waste Shipped Offsite For Burial Or Disposal

1. Type of Waste Unit 12 Month Estimated Total Error, Period  %

a. Spent resins, filter sludges, Cubic Meter 17.35 1.00E1 evaporator bottoms, etc. Ci 46.59 5.60E1

b. Dry compressible waste, Cubic Meter 63.2 1.O0EI contaminated equipment, etc. Ci 0.016 5.60E1

c. Irradiated components, Cubic Meter 0.09 1.0OE1 control rods, etc. Ci 36 5.60E1

d. Other (Processed Waste) Cubic Meter 0 NA Ci 0 NA

2. Estimate of major nuclide Unit Nuclide .12 Month Period composition (by type of waste)

a. Spent resins, filter sludges,  % Cs-137 76.10 evaporator bottoms, etc.  % Co-60 2.65

% Ni-63 10.49

% Sr-90 8.72

% Pu-238 0.12

% Pu-239/240 0.21

% Pu-241 1.22

% Am-241 0.08

% Cm-243/244 0.02

b. Dry compressible waste,  % H-3 0.0 contaminated equipment, etc.  % C-14 3.43E-2 Fe-55 5.16E0

% Co-60 1.84E1

% Ni-59 1.35E-1

% Ni-63 3.48E1

% Sr-90 1.31 E0

% Tc-99 2.85E-1

% 1-129 3.82E-2

% Cs-137 3.31E1

% U-234 1.90E-3

% U-238 1.84E-3

% Pu-238 2.81 E-1

% Pu-239 3.35E-1

% Pu-241 4.23E0

% Am-241 1.54E-1

% Cm-243 3.22E-1

% Cm-244 1.85E-4 14

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 5 - Continued SOLID WASTE AND IRRADIATED FUEL SHIPMENTS

c. Irradiated components,  % H-3 0.0 control rods, etc.  % C-14 7.90E-1

% Fe-55 4.10E-1

% Co-60 4.20E1

% Ni-59 4.70E-1

% Ni-63 5.42E1

% Sr-90 4.60E-1

% Zr-93 5.30E-1

% Nb-94 2.OE-2

% Tc-99 3.86E-4

% Sb-125 6.10E-1

% Cs-137 4.90E-1

% Pu-238 2.69E-4

% Pu-239 7.02E-5

% Pu-241 3.58E-3

% Am-241 5.84E-4

% Cm-243 9.81 E-4

% Cm-244 2.52E-6 15

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 5 - Continued SOLID WASTE AND IRRADIATED FUEL SHIPMENTS

3. Solid Waste Disposition Number of Mode of Destination Shipments Transportation 2 Truck Energy Solutions, LLC 5 Truck Studsvik 1 Truck Barnwell Waste Management Facility B. Irradiated Fuel Shipments

1. ted Fuel Disposition Number of Mode of Destination Shipments Transportation I None N/A N/A 16

HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 IV. RADIOLOGICAL IMPACT ON MAN A comparison of calculated doses from various paths has shown that the offsite doses are primarily due to direct radiation and to the consumption of aquatic foods. Maximum doses to individuals (for the maximally exposed organs and age groups) are summarized in Table 6. These doses comply with 40 CFR 190 as there are no other uranium fuel cycle facilities within 8 km of the Humboldt Bay Power Plant.

A. Doses to the average individual in the population from all receiving-water-related pathways were calculated for detected releases, based on the guidance of Regulatory Guide 1.109. The highest results were less than 0.01 mrem/yr (total body) for the Adult age group, and less than 0.030 mrem/yr for the bone of the Adult age group.

These doses are well below the 10 CFR 50, Appendix I numerical guidelines for limiting effluents as low as is reasonably achievable (ALARA) (3 mrem/yr to the total body and 10 mrem/yr to any organ).

B. Total body doses to the average individual in the population from gaseous effluents to a distance of 50 miles from the site are not calculated, but this dose is less than the total body dose to an average individual present at the maximally exposed location. For an average individual at the maximally exposed location, the total body dose (calculated with the same dispersion and deposition parameters as were used to calculate maximum exposure) was less than 0.001 mrem/yr.

This maximum calculated dose is well below the 10 CFR 50, Appendix I numerical ALARA guidelines (10 mrem/yr for gamma radiation and 20 mrad/yr for beta radiation from noble gases and 15 mrem/yr-to any organ from tritium and radionuclides in particulate form).

C. Total body doses (to the average individual in unrestricted areas from direct radiation from the facility) are based on TLD results of stations at the site boundary, using the shoreline occupancy factors given in Regulatory Guide 1.109 for the highest average potential individual (Teen age group). For this group, direct radiation would result in an exposure of 0.01 mrem/yr.

This maximum potential dose is well below the 10 CFR 20.1302(b)(2)(ii) limit of 50 mrem/yr from external sources necessary to demonstrate compliance with the 10 CFR 20.1301 dose limit for individual members of the public.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 TABLE 6 RADIATION DOSE FOR MAXIMALLY EXPOSED INDIVIDUALS I Dose, milli-rem I First Second Third Fourth Annual Dose Source Quarter Quarter Quarter Quarter Total Liquid Effluents Water-related Pathways'(1) <0.01 (5) <0.01 (5) <0.01 (5) <0.01 (5) <0.01 (5)

<0.01 (6) <0.01 (6) <0.01 (6) <0.01 (6) <0.01 (6)

Airborne Effluents Particulates (2) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00 (7) 0.00(7)

Noble Gases (3) 0.00 0.00 0.00 0.00 0.00 Direct Radiation (4) <0.01 <0.01 <0.01 <0.01 0.01 Notes

1. Maximum total body and organ doses to individuals in unrestricted areas from receiving-water-related exposure pathways were calculated from the average concentrations of liquid releases detected during the report period, following the applicable portions of Regulatory Guide 1.109 and NUREG-4013.

2. Maximum total body and organ doses to individuals in unrestricted areas from airborne-particulate-related exposure pathways were calculated from the average concentrations of airborne particulate releases detected during the report period, following the applicable portions of Regulatory Guide 1.109 and NUREG-4013.

3. Total body and skin doses to potentially exposed individuals located at the point of maximum offsite ground-level concentrations of radioactive gaseous effluents calculated because there were detected releases of radioactive noble gases.

4. Total body doses (to the maximum individual- in the population) are based on TLD results of stations at the site boundary, using the shoreline occupancy factors of Regulatory Guide 1.109 for the maximum potential individual (Teen age group).

5. Total body (Adult age group).

6. Bone (Adult age group).

7. For stack releases, a majority of the results were "not detected", resulting in a total activity considered "not detected", for which nodose is calculated.

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HUMBOLDT BAY POWER PLANT ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT 2008 V. CHANGES TO THE OFFSITE DOSE CALCULATION MANUAL (ODCM)

The ODCM was revised once during the report period. The changes maintained the level of radioactive effluent control and dose commitment required by regulation, and did not adversely affect the accuracy or reliability of effluent, dose or setpoint calculations.

Revision 15 to the ODCM was reviewed by the Plant Staff Review Committee (PSRC) on October 2, 2008, approved by the Plant Manager on October 2, 2008, and became effective on January 12, 2009.

The changes in this revision are to reflect the movement of all the spent fuel (noble gas source term) to the Independent Spent Fuel Storage Installation (ISFSI). All references to noble gases were removed from the ODCM.

Also, four TLD locations were added at the ISFSI fenceline.

VI. CHANGES TO THE PROCESS CONTROL PROGRAM (PCP)

There were no changes to the Process Control Program during the report period.

VII. CHANGES TO RADIOACTIVE WASTE TREATMENT SYSTEMS There were no changes to the Radioactive Waste Treatment Systems during the report period.

VIII. INOPERABLE EFFLUENT MONITORING INSTRUMENTATION There was no inoperable effluent monitoring instrumentation during the reporting period.

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