ML20035D560

Suppl to Seabrook Station Semiannual Radioactive Effluent Release Rept,Radiological Impact Assessment,1992

ML20035D560
Person / Time
Site:	Seabrook
Issue date:	12/31/1992
From:	NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:
Shared Package
ML20035D558	List: ML20035D555 ML20035D560
References
NUDOCS 9304130309
Download: ML20035D560 (14)

Text

. -.

t Seabrook Station Supplemental Effluent Release Report i

Radiological Impact Assessment For 1992 1

)

I. Introduction Doses resulting from liquid and Saseous effluents from Seabrook Station i

during 1992 vere calculated in accordance with Method II as defined in the Station Offsite Dose Calculation Manual (ODCM). The calculational methods used follow the models in Regulatory Guide 1.109. The calculations included maximum total body doses and organ doses frcm all liquid releases, maximum offsite organ r

doses resulting from airborne iodines, tritium and particulate radionuclides, and

\\

maximum offsite beta air and gamma air doses from airborne noble gases.

In

[

t I

l addition, the doses were also calculated for the special receptor locations l

t inside the site boundary: the Education Center and the " Rocks".

The doses associated with effluent releases during 1992 are summarized in Table A.

.j The calculated maximum annual total body dose and the maximum organ dose from liquid effluents represent, respectively, 0.06% and 0.09% of the dose limits

{

est ablished by Technical Specification 3.11.1.2.

The calculated annual maximum dose from airborne iodine, tritium and particulate radionuclides for offsite

-i receptor locations represents 0,v7% of the dose limit established by Technical i

Specification 3.11.2.3, whereas the calculated maximum annual beta air and gam =a air doses from airborne noble gases for offsite receptor locations represent, j

respectively, 0.001% and 0.002% of the dose limits established by Technical i

Specification 3.11.2.2.

The calculated annual beta air and gamma air doses from airborne noble gases for the Education Center vere, respectively, 0.0003% and l

0.0001% of the limits in Technical Specification 3.11.2.2, whereas, for the j

Ro cks " the annual doses were 0.004% and 0.006% of the respective Technical 4

l-l 1

i 930413030 h h 43 4

PDR ADOC PDR R

l

i Specification limits. The calculated annual doses from airborne iodines, tritium and particulate radionuclides at the Education Center and the " Rocks" were, respectively, 0.001% and 0.015% of the limits in Technical Specification i

3.11.2.3.

i The sum of the maximum whole body doses from all exposure pathways for the liquid and gaseous effluents, plus the direct whole body dose from station operation, was 2.7e-3 mrem to a hypothetical individual. This total whole body dose conservatively represents 0.01% of the whole body dose limit for a me=ber of the public as set forth in 40CFR190, and demonstrates compliance with that code.

(

a l

t

[

1 1

h

.I 2

t

?

... _ _ ~

c II. Method for Calculatinr the Total Body and Maximum Orran Doses Resultine from Licuid Releases i

The computer code IDLE, which is consistent with the models in Regulatory I

Guide 1.109 (Reference 1), was used to calculate the total body and organ doses resulting from liquid effluents from Seabrook Station. The general equations A-

[

i 3, A-4, A-5, A-6 and A-7 from Regulatory Guide 1.109 are applied in IDLE. The I

total body doses and the organ doses are evaluated for each of the four age groups (i.e., infant, child, teen and adult) to determine the maximum total body t

dose and maximum organ dose via all existing exposure pathways (i.e., fish and 5

aquatic invertebrate ingestion, and shoreline exposure) to an age-dependent i

individual.

The values for the various factors considered in equations A-3 i

through A-7 have been taken from Regulatory Guide 1.109 and the Station Offsite

.l Dose Calculation Manual (ODCM) (Reference 2). The specific values used for the usage factor (U,p), mixing ratio (M ), bioaccumulation factor (B3p), dose factors p

(D,ip3 ), transit time (t ),

transfer constant from water to sediment (K ),

i p

c exposure time' for sediment or soil (t ), and shore width factor (V) are provided 3

by the reference sources as summarized in Table B.

The flow rate of the liquid j

?

]

effluent (F) and the radionuclide activities (Qi) are measured specifically prior 1

to each liquid release.

The values for half lives for radionuclides (T ) and 1

i j

their radioactive decay constants (A ) have been taken from Kocher (Reference 3).

3 i

The exposure pathways considered in the calculations of total body and

~!

maximum organ doses resulting from liquid discharges from Seabrook Station have been limited to ingestion of aquatic foods and exposure to shoreline deposits.

The dose calculations do not include the ingestion of potable water and irrigated vegetation as potential exposure pathways.,ecause the liquid effluents from the plant are discharged into salt water.

3 I

4 Table A presents the calculated liquid pathway doses for each calendar

. quarter and also the total for the year.

l f

i 9

h f

t i

i f

a i

i 4

e

?

s

[

t 3

4 6

4 1

E f

4 i

h I

i 1

l l

III. Method for Calculatint the Cart:ra and Beta Air Doses from Noble Cases i

The computer codes AIRAD and AEOLUS 2 (Mod 05) vere used for the calculation-

)

of both the gamma and beta air doses resulting from noble gases present in gaseous effluents releaced from Seabrook Station. The features and use of AEOLUS 2 (Mod 05) for the calculation of atmospheric dispersion factors (i.e., Chi /Q factors) from recorded meteorological data (i.e.,

meteorological data measurements taken during the time of the release) are described in section B.7.3.2 of Seabrook's ODCM. Meteorological dispersion factors concurrent with periods of batch gas releases are calculated along with the values for quarterly l

average dispersion fac. tors. The atmospheric dispersion factors calculated using AEOLUS 2 (Mod 05) were, in turn, used in the gamma and beta air dose calculations by AIRAD.

AIRAD is consistent with the c:odels presented in Regulatory Guide 1.109, general equations B-4 and B-5.

The values for the dose factors, DF[ and l'

r DF, have been taken from Table B-1 in Regulatory Guide 1.109.

j 3

Table A lists the calculated air doses for each calendar quarter, and the total for the' year.

F h

4 i

{

J i

i 5

l i

i 9

IV. Method for Calculatinr the Critical Orcan Dose Resultine from Todines.

Tritium and Particulates with Tm Greater than 8 Days in Caseous Re~ teases e

The computer codes AEOLUS 2 (Mod 05) and ATMODOS were used for the calculation of the organ doses resulting from iodines, tritium and particulates i

with half-lives greater than 8 days present in gaseous effluents released from Seabrook Station. The features and use of AEOLUS 2 (Mod 05) for the calculation i

1 of atmospheric dispersion factors (i.e.,

Chi /Q factors) from recorded meteorological data (i.e., meteorological data measure =ents taken during the time f

of the release) are described in section B.7.3.2 of Seabrook's ODCM.

[

t Meteorological dispersion factors concurrent with periods of batch gas releases were calculated along with the values for quarterly average dispersion factors.

The atmospheric dispersion factors calculated using AEOLUS 2 (Mod 05) were, in 4

turn, used in the dose calculations by ATMODOS.

ATMODOS calculates the organ i

doses (

i.e.,

dose to bone, liver, kidney, lung, lower large intestine, total body, and skin) due to the presence of radionuclides other than noble gases in i

gaseous effluents, and is consistent with the acdels presented in Appendix C of Regulatory Guide 1.109. The pathways considered in the dose calculations are the ground plane, inhalation, and ingestion of stored vegetables, fresh garden l

l vegetables, milk and meat. The critical organ dose is determined for the offsite location (e.g., site boundary, nearest resident or farm) of receptor pathways as identified in the most recent annual land use census.

The total body dose-r

- contributions via the ground plane and inhalatien pathways calculated by as ATMODOS have also been included in the total body dose estimates for the special receptor locations inside the site boundary.

Equations C-1 through C-13 are applied in the ATMODOS calculation of the critical organ doses. The input data and assu=ptions are those provided in Appendix C of Regulatory Guide 1.109, 6

i

except where site-specific data and assu=ptions have been identified in Tables B.7-2 and B.7-3 of Seabrook's ODCM. These two ODCM tioles provide the options for special conditions, depending on the type of receptor being evaluated at a specific location, that are to be applied in Method II calculations.

The receptor type controls the exposure pathways for calculational purposes.

The receptor types used in the dose calelations were a resident receptor (which considered the ground plane, inhalation and vegetable ingestion exposure pathways), a milk receptor (which considered the ground plane, inhalation, vegetable and milk ingestion exposure pathways) and a boundary and radius receptor (both of which considered the ground plane and inhalation exposure pathways). The resident and milk receptor locations for the various sector were based on the 1992 land use census data for Seabrook Station (Table D).

The-radius receptor locations were applied at several distances in each sector to in:.

e that the location of the maximum doses were not overlooked.

2 Depletion of the plume during transport is considered by AE01.US 2 (Mod 05) in the calculations of atmospheric dispersion factors (e.g.,

calculation of

[X/Q)D). A shieldig faci.or (Sy) of 0.7 is applied for residential structures.

The source for the values of the various factors used in equations C-1 throu5h C-13 are summarized in Table C.

l G

7

V. References 1.

Calculation of Annual Doses to Man fro:n Routine Releases of Reactor Effluents for the Purposes of Evaluating Compliance with 10CFR Part 50, Appendix I, Reg. Guide 1.109, Rev 1., Oct. 1977.

2. Station Offsite Dose Calculation Manual, Rev 12.

3.

Kocher, D.C.,

Dose-Rate Conversion Factors for Exposure to.

Photons and Electrons, Health Physics, Vol. 45, No. 3, Sept. 1983.

n E

a 8

~

3 TABLE A Seabrook Station Effluent and Vaste Disposal Semiannual Report i

1992 I

i Maximum (*)Off-Site Doses and Dose Commitments to Members of the Publie Dose (mrem) N 1st 2nd 3rd 4th Source Ouarter Ouarter Ouarter Ouarter Ye a r(*)

i Liquid Effluents:

Total Body Dose 4.8e-04 4.4e-04 3.8e-04 3.Be-04 1.7e-03 Organ Dose 2.8e-03 2.2e-03 1.8e-03 1.7e-03 8.5e-03

-l a

(1)

(1)

(1)

(1)

Airborne Effluents:

Iodines, Tritium and 9.5e-06 3.0e-05 4.le-04 6.Be-04 1.le 03 Particulates (2)

(3)

(4)

(5) j Noble Gases Beta Air 1.le-04 2.3e-05 8.5e-06 9.le-07 1.4e-04 i

(crad)

(6)

(7)

(8)

(9) 1 Ga==a Air 1.5e-04 4.le-05 3.5e-06 1.8e-06 2.0e-04 (mrad)

(6)

(7)

(8)

(9)

Doses (arem) at Receptor Locations j

Inside Site Boundary (d):

Education Center (SW, 488m)

Beta Air Dose (mrad) 5.3e-05 2.5e-07 5.3e-05 Camma Air Dose (mrad) 7.9e-05 3.5e-06 8.3e-05

-l Organ Dose (arem) 6.6e-06 8.Be-05 7.0e-05 1.6e-04 i

(10)

(11)

(11) i l

The " Rocks" (NE/ENE, 244m)

(mrad) 6.Se-04 4.8e-05 2.0e-05 Beta Air Dose 7.2e-04 Camma Air Dose (crad) 5.7e-04 2.7e-05 5.le-06 6.0e-04 Organ Dose (mrem) 5.9e-05 4.9e-06 1.2e-03 1.0e-03 2.3e-03 (10)

(10)

(11)

'(11)

J i

a 9

j l

TABLE A (continued)

Seabrook Station Effluent and Waste Disnosal Semiannual Renort 1991 Maximum (*)Off-Site Doses and Dose Commitments to Members of the Public Dose (mremi tb)

Ist 2nd 3rd 4th Source Ouarter Quarter Quarter Quarter Year (*)

Direct Dose From Plant Operation (*)

0 (a)

" Maximum" means the largest fraction of correspending 10CFR50, Appendix 1, dose design objective.

(b) The numbered footnotes indicate the age group, organ, and location of.ne dose receptor, where appropriate.

(1) Child / bone.

(6) S-914 meters.

(2) Child /whole body, ESE-2414 meters.

(7) SW-914 meters.

(3) Child /whole body, S-966 meters.

(8) WNW-914 meters.

(4) Teen /GI-LLI, SW-966 meters.

(9) E-2438 meters.

(5) Child /GI-LLI, SSW-966 meters.

(10) Teen /whole body.

(11) Teen / lung.

(c)

" Maximum

• dose for the year is the sum of the maximum doses for each quarter. This results in a conservative yearly dose estimate, but still vell within the -limits of 10CFR50.

(d) For each special receptor location, the whole body and organ doses calculated for the airborne effluent releases were adjusted by the occupancy factor provided in the Station ODCM (i.e., 0.0014 for the Education Center and 0.0076 for the

• Rocks").

(e) Only station sources are considered since there are no other facilities within five miles of Seabrook Station.

1992 data for the closest off-site environmental TLD locations in each sector (as listed in Table B.4-1 of the Station ODCM) were compared o pre-operation data from 1986-1988 for the same locations. No statistical difference which could be attributed to station sources was identified.

10

Table B Sources of the Values of Factors Used in Liquid Dose Equations l

Factor Source

,l U,p Table B.7-1, Station ODCM Ny Section B.7.1, Station ODCM (value-0.1 'for aquatic foods and 0.025 for shoreline)

B Table A-1, Reg. Guide 1.109 ip D,1g Tables E-11 through E-14, R.G.1.109 t

Section B.7.1, Station ODCM p

K, Reg. Guide 1.109 t

Reg. Guide 1.109 3

W Table A-2, Reg. Guide 1.109 (value-0.5) i l

I i

i 11

2 l

Table C I

i Sources of values for the Factors Used in Dose Equations for Gaseous Releases Factor Source tb Reg. Guide 1.109

{

h Kocher (Reference 3) 3 3

DFG Table E-6, Reg. Guide 1.109 13

[X/Q)D Calculated by AEOLUS 2 (Mod 5)

R.

Table B.7-3, Station ODCM j

DFA Tables E-7 through E-10 R.G.1.109 33, i

d Reg. Guide 1.109 i

P,t,th and Y, Table B.7-2, Station ODCM r

Table E-15, Reg. Guide 1.109 B,

Table E-1, Reg. Guide 1.109 1

p Reg. Guide 1.109 H

Table B.7-2, Station ODCM F.

Tables E-1 and E-2, R.G. 1.109 i

Qr Table E-3, Reg. Guide 1.109 I

ti Reg. Guide 1.109 l

h

\\

d f

Table B.7-2, Station ODCM l

p f

f, Table B.7-2, Station ODCM Fr Table E-1, Reg. Guide 1.109 t,

Table E-15, Reg. Guide 1.109 12 1

1 i

i

I Table C Sources of Values for the Factors Used in Dose Equations for Gaseous Releases l

(continued)

Factor Source DFI Tables E-11 through E-14,

.l ip R.C.1.109 i

I U[,U" Table B.7-3, Station ODCM 1]l[,UL Table B.7-3, Station ODCM

)

f,,ft Reg. Guide 1.109 cfi Calculated by AEOLUS 2 (Mod 5) l A.

Table E-15, Reg. Guide 1.109 Qy Table E-3, Reg. Cuide 1.109 i

1 h

~

}

t t

+

?

l i

1 1

13 J

?

l Table D Receptor locations

• for Seabrook Station i

Milk Anitr:21 Nearest Nearest within 5 Mi j

Resident Carden Radius Sector mile (km) mile (km) mile (km)

N 0.6 (1,0) 2.6 (4.2) i NNE 2.0 (3.2) 2.0 (3.2)

NE 1.5 (2.4) 1.6 (2.6)

ENE 1.6 (2.4) 1.6 (2.6)

E 1.6 (2.6) t ESE 1.5 (2.4)

SE 1.5 (2.4)

SSE 0.6 (1.0) 0.7 (1.1)

S 0.6 (1.0) 0.8 (1.3)

SSV 0.6 (1.0) 0.8 (1.3)

SW 0.6 (1.c) 0.8 (1.3) 3.2 (5.2) usu 0.7 (1.1) 0.7 (1.1)

W 0.6 (1.0) 0.7 (1.1) mm 0.6 (1.0) 1.0 (1.6) 3.0 (4.8) 3.8 (6.1) 4.8 (7.7) i im 0.6 (1.0) 0.7 (1.1) 4.4 (7.1)

NNW 0.7 (1.1) 0.7 (1.1) 3.4 (5.5)

• Locations based on 1992 Land Use Census.

i l

0 14 I

-