ML21104A149

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2020 Annual Radioactive Material Release Report
ML21104A149
Person / Time
Site: Duane Arnold NextEra Energy icon.png
Issue date: 04/14/2021
From: Hansen P
NextEra Energy Duane Arnold
To:
Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML21104A148 List:
References
NG-21-0008
Download: ML21104A149 (38)
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Text

NEXTera.

ENERGY~

DUANE ARNOLD April 14, 2021 NG-21-0008 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No. 50-331 Renewed Op. License No. DPR-49 2020 Annual Radioactive Material Release Report Please find as the Enclosure to this letter, a copy of NextEra Energy Duane Arnold, LLC's (hereafter, NextEra Energy Duane Arnold) 2020 Annual Radioactive Material Release Report for the Duane Arnold Energy Center (DAEC). This report satisfies the requirements of Defueled Offsite Dose Assessment Manual (DODAM) Section 8.2 .1 and Technical Specification Section 5.6.3.

This letter makes no new commitments nor changes to existing commitments.

Should you have any questions regarding this matter, please contact Michael Casey at (319) 851-7606.

£~t Decommissioning Director NextEra Energy Duane Arnold, LLC Enclosure cc: Administrator, Region Ill, USNRC Project Manager, DAEC, USNRC Inspector, DAEC, USNRC NextEra Energy Du ane Arn old , LLC, 3277 DAEC Road, Palo, IA 5232 4

Enclosure to NG-21-0008 Duane Arnold Energy Center 2020 Annual Radioactive Material Release Report 517 pages to follow

EXTera*

ENERGY4 DUANE ARNOLD 2020 Annual Radioactive Material Release Report Duane Arnold Energy Center Cedar Rapids, Iowa ' ,

Docket No. 50-331 January 1, 2020 through December 31, 2020

2020 Annual Radioactive Material Release Report Duane Arnold Energy Center DOCKET NUMBER. 50-331 Prepared By: O ~

Daron Tanko, Rad-Effluents Coordinator Date:

Approved By:~~

rrcfuiel c::;o ~Manager

~CtlefTl Date: 'l/Jf2.-1

N x l

  • a
  • ner911 Res ourc >s, ' O lll Duane Arnold Energy Center Decommissioning Emergency preparedness Funding Allor lho plant shuts dovm, th11 ~l:ilitles ICf on mlEfge<l~Y NllX1£'ro. Energy Rernuroos ond U1e joint ov.llQr.l \~II !XI}'

dllC!lXIDa drnmotlc:!lly. 100 Ouano Amcld Enargy ~nkir fa' 0Ullil9 #rokl's dQcx;m~!!.Slon1n*g. Nuclia! pow;r

\'111 malnlo.ln ~pobl~ties to addre:;s arry posalblily of on plnntsaro roqulrad by the NRO to put a!ldo funds for 11m11rg;incy GI b plan!, no mattor ho11 unl~y. i.nUI al 1\191 hllll decommlsofonlrY,J v.tllf; lhw pfll.llt Jc pporat!ng. ThQ monw been pln06CI h lcflg'-li<m olcra~ Oroe.oll th u~ ~Iii h!IS Js lnvo!lad Jn CfQ(jlcat.Qd tru~ts . over 1he lffetime of )he pllVlt.

boon pla~ h lciig*l<<m alcrng;>, V-.e risk of on emergeooy The fund dlstr1bution Is cOiefully moritorl!<I b'J a lhfd party,

!hat could all~ the conimlllltylsvlrtuall)t 11llmlnlllid. N&<<IEro. En11rgy Ro1ourcos ocUmatos thci dc:.eomrrlS!!onfng Ho1.'i','ir. a :ii¢urity fc v.1u rcmDln to protl)Ct 11111 ladlly. of Duane Arnold Is ~Uy funded.

Loam more: NextEraEnergyResources.com/DuaneArnoldlnfo

I-Jo , t *1nE11 r(\ y fh~:.0 111 e * .n(l l 1 Frequently Asked Questions W11at happens to tno nuclear material on site? What happens to the employees?

Tho u!IQCI lual v.111 oo pla!Ald In lorog.te1T11 dry ntorog9 on Dile Our goo! from the 1~y be;ilnnlng of thl:i f::l'O~M hos bwn v~lhln thro11 yoars or t~ plant sh.1!tlrr.1 down, lofmihfmlZ;l the lmpocl en our t>mpoye~ 1111d l~r famlllos.

'Na ccotinug to work wllh each and every hlllm mamba' to Tho f'Qa.ctor buUdlng ~ occumulat;o;t ~" re~lduw help !hem propnra for Iha !Mlnlual ohutdown.

rodk>actll'e P<1rtlc161:l owr the. Illa ol 1119 plnnl. Thi bulldl11g11 v.111 remain vacant for 60 yoors 00101'Q being domcilllhod. Th DUpport D.lone Arnold Energy Gentili" emplCl)'eQS dullng Tha ewntual demclllion of the ro000tcr bulldlrq will~ tho tronslUol\ N~tE.r.l Energy R~roes l'W d~cpad u conduolod wtth care Dnd r;;ispacl lcr Iha nurroundlng cornprehen:il/9 omploygo plan thoi lnCIUdO!I M GOhDnCQ.;I

£r1Vlronmsot. Arry other buildlngc refn!linfng on lhe i;it11 wlll retirGJTient progrom tor eligible empl;Jyl;les, pl.wi;ment In DJ!¢ bo dorn~lshod nt IH:i tlm;. oths- Jobs through:>ul lhQ ccmpany, llUpport ~lo!olilS wtiloh lnclucl6l denllng wl1h chang-0, proparlng ICf retlremonl, Why are you waiting so long to dornollsh 1wil11'9 resumeo, Job ooorch~ and carao.r llilto. NextEra the bulldlngs? EMrgy RB!lOUrte:i a!GO lo partnering with Alliant Energy oo:I other companle9 In Ille mergy ln:tustry to ldEntlly WhUo the Dua no Arnold EnE<QY Contor Is .n vr.ry cl!Xm oppcrtunlUll!l fer Mlploye;;s.

facility, 1h& £i1Uf,:mel'\t uSEuac.n;i9, wo allow timG fer tho l\'.ltur-al procQ!laM to reduce Iha What (loes stalling look Ilka In lhe months and lnteoolty of Iha radk-a::tlve p:irtlclas. ~hen the time colT'l&G years after shutdown?

to II.Ike bulldlrQS down, II will oo OO!ler oo lho el"Nlronment The 11tatlco wUI otil l)GQd a grcup of toorn mMll:<<o lU'ld moni oconcrnlol!l to r'1tl'lov11 mnlirial frcm the sftQ lo monltcr Iha plant and pr<Mdo security for oovGi'ol YQG~ art9r Of)QmiJon~ ¢ Wl$9 and lhroughc:ul thi Tl19 ~119 Yrlll continue to b~ J:<O'"tQnt !Uol 19 romovocl lrom U10 cf to.

NoxtEra Enocgy Rooouroos bellevos ll'c lrnportMI lo oparalll ns*buslr'lQS.S In harmonywilh U1e erwlronmanl and oor nolghborn. l/'1'G takri our rQSponslbillty to S(ICI that the $~ Is malntolMd In a way lhat bllf!alit.o th& Ieng IGtrn huollh of Iha community \'Q ry s'flou!iy. Y..';;; will continwi to wo1k v,Hh 'Iha NAO until the d'1COmmlsslonlng prooes:i 1$ complete.

W11at will happen to tile slle?

What wlll they do there?

NextEm Energy Duane Arnold lo evaluatina rodev.-ilopment oppor:tun!Hea at the sits, btJl It would bEl prernnluro lo

!!pQOUlato ol:<..il Wh\11 diel3ICO~ might be m~. ~~ voill continue to &valu<1te ix:iwnt1DI r'4~CQmont opPorlunltl~

Q::l ng forward.

IO! TOO

EXECUTIVE

SUMMARY

The Duane Arnold Energy Center (DAEC) permanently shut down on August 10,2020, and the reactor fuel has been placed in the spent fuel pool. By letter dated August 27, 2020 (Accession No. ML20240A067), NextEra Energy Duane Arnold (NEDA) certified permanent cessation of power operations at the DAEC. By letter dated October 12, 2020 (ML20286A317), NEDA certified permanent defueling of the reactor at DAEC. Therefore, as specified in 10 CFR 50.82(a)(2), the 10 CFR Part 50 license for DAEC no longer authorizes operations of the reactor or emplacement or retention of fuel into the reactor vessel.

The contribution of dose to a member of the public most likely to be exposed from liquid and gaseous effluent releases was calculated using the Meteorological Information and Dose Assessment System (MIDAS) computer program in accordance with the ODAM. The calculated doses for gaseous and liquid effluent releases are less than the regulatory limits stated in Appendix I to 10 CFR 50 and in 40 CFR 190.

Supportive environmental data for the 2020 dose assessment can be found in the Duane Arnold Energy Center 2020 Annual Radiological Environmental Operating Report.

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Table of Contents REGULATORY LIMITS 8 MAXIMUM PERMISSIBLE CONCENTRATIONS 9 AVERAGE ENERGY 9 MEASUREMENTS OF TOTAL RADIOACTIVITY 9 GASEOUS EFFLUENTS 10 Table 1A - Gaseous Effluents - Summation of All Releases Table 18 - Gaseous Effluents by Quarter Table 1C- Gaseous Effluents by Release Point Estimated Release of Gaseous Carbon-14 Gaseous Effluents: Historical Trend LIQUID EFFLUENTS 17 Table 2A - Liquid Effluents - Summation of All Releases Table 28 - Liquid Effluents RADIOACTIVE SOLID WASTE 19 Shipments in 2020 Waste Classification per 10 CFR 61 Summary Tables of Radioactive Solid Waste RADIOLOGICAL IMPACT ON MAN 24 Conclusion

SUMMARY

OF METEOROLOGICAL DATA 26 Stability Class Data 33' Wind Rose Data 33' Stability Class Data 156' Wind Rose Data 156'

SUMMARY

OF GROUNDWATER PROTECTION INITIATIVE ISSUES 29 DESCRIPTION OF CHANGES TO THE OFFSITE DOSE ASSESSMENT MANUAL 32 Revision 41 ~Revision 42 ~ Defueled Offiste Dose Assment Manual Revision O ATTACHMENT 1 -GROUNDWATER PROTECTION PROGRAM SEWAGE EFFLUENT RESULTS ATTACHMENT 2-0FFSITE DOSE ASSESSMENT MANUAL (ODAM)

ATTACHMENT 3-DEFUELED OFFSITE DOSE ASSESSMENT MANUAL (OODAM)

Page 6

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT REGULATORY LIMITS Fission and Activation Gases Dose Rate

  • Less than 500 mrem/year to the whole body.
  • Less than 3000 mrem/year to the skin.

Gamma Air Dose

  • Less than or equal to 5 mrad/quarter.
  • Less than or equal to 10 mrad/year.

Beta Air Dose

  • Less than or equal to 10 mrad/quarter.
  • Less than or equal to 20 mrad/year.

Airborne Particulates, Iodines and Tritium Dose Rate

  • Less than 1500 mrem/year.

Dose

  • Less than or equal to 7.5 mrem/quarter to any organ.
  • Less than or equal to 15 mrem/year to any organ.

Liquid Effluents Dose

  • Less than or equal to 1.5 mrem to the whole body during any calendar quarter.
  • Less than or equal to 5 mrem to any organ during any calendar quarter.
  • Less than or equal to 3 mrem to the whole body during any calendar year.
  • Less than or equal to 10 mrem to any organ during any calendar year.

Concentration Liquid effluents released from the site to unrestricted areas shall not exceed ten times (1 Ox) the concentrations listed in Appendix B, Table 2, Column 2 to 10 CFR 20.1001 -

20.2402.

40CFR190 and 10CFR72 Dose

  • Less than or equal to 25 mrem annual whole-body dose.
  • Less than or equal to 75 mrem annual thyroid dose.
  • Less than or equal to 25 mrem annual dose to any other critical organ.

Page 7

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT MAXIMUM PERMISSIBLE CONCENTRATIONS Dose rates, rather than effluent concentrations, are used to calculate permissible release rates for gaseous effluents. The maximum permissible dose rates for gaseous releases are defined in Duane Arnold Offsite Dose Assessment Manual (ODAM) and the Defueled Offsite Dose Assessment Manual (DODAM). ODAM-DODAM Limiting Condition for Operation (OLCO) 6.2.2.

Liquid effluent concentrations are limited per ODAM-DO DAM OLCO 6.1.2 to ten times (1 Ox) the concentration specified in 10CFR20 Appendix B, Table 2, Column 2.

AVERAGE ENERGY The ODAM-DODAM limits dose rates at or beyond the site boundary due to the release of noble gases to less than or equal to 500 mrem per year to the total body and less than or equal to 3,000 mrem per year to the skin. Average energy is not used to determine dose to the public.

Compliance with these limits is demonstrated based on dose calculations using measured isotopic concentrations of effluent streams and not based on gross count rate measuring systems.

Therefore, the average beta and gamma energies (E-BAR) for gaseous effluents as described in Regulatory Guide 1.21 "Measuring, Evaluating, and Reporting Radioactivity in Solid Wastes and Releases of Radioactive Materials in Liquid and Gaseous Effluents from Light-Water-Cooled Nuclear Power Plants," are not applicable.

MEASUREMENTS OF TOTAL RADIOACTIVITY Gaseous Effluents

  • Gaseous Effluents from the Offgas Stack, Reactor Building Vents, Turbine Building Vent and the Low Level Radwaste Storage and Processing Facility (LLRPSF) are continuously sampled for iodines and particulates. Sample media is changed weekly and analyzed by gamma spectroscopy. The gross alpha analyses are performed onsite. The particulate filters are composited on a quarterly basis and sent to a vendor for Sr-89, Sr-90, Fe-55 and Ni-63 analysis. Total error is calculated based on stack flow error, sample flow error, and analytical error.
  • Noble gas grab samples of the same four release points are obtained monthly and analyzed by gamma spectroscopy. Total error is based on stack flow error, analytical error, and calculated sampling error.
  • Tritium samples from all four release points are obtained quarterly and analyzed by liquid scintillation. Total error is based on stack flow error, analytical error, and calculated sampling error.
  • A beta sensitive radiation detector provides continuous monitoring at each of the above described release points. For the year 2020, there were no instances where ODAM-DODAM required gaseous radiation monitoring or sampling systems were inoperable on an active release point for a period of 30 (contiguous) days or more. (ODAM-DODAM OLCO 6.2.1.1 A.2)

Page 8

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Liquid Effluents

  • Service water systems are composite sampled once per week for gamma emitters. Portions of the weekly service water samples are composited for a monthly analysis for tritium and gross alpha. If there is a positive identification of reactor by-product radioactivity in these samples, Sr-89, Sr-90 and Fe-55 analyses are performed. Total error is based on the volume discharge error and analytical error.
  • ODAM-DODAM defined "Clean Systems" are sampled prior to batch release or continuous release with composite sampling. Samples are analyzed for gamma emitters and tritium. If reactor by-product gamma emitters are identified, analyses for Sr-89, Sr-90 and Fe-55 are performed. "Clean Systems" include CST Containment Pit, Transformer Pit, Neutralizing Tank 1T022, FRAC tanks, and temporary mitigation of groundwater in a monitoring well.
  • Beginning in November 2020, there were twenty radioactive batch releases of liquids from plant radwaste system using the ALARA filter enhancement. The primary isotope was tritium.
  • The permanent groundwater mitigation system is designed to remove tritiated groundwater from the shallow aquifer. The composite sample is collected once per week and analyzed for gamma emitters and tritium. If reactor by-product gamma emitters are identified, analyses for Sr-89, Sr-90 and Fe-55 are performed. Total error is based on the volume discharge error and analytical error. For 2020, there were four continuous releases from the permanent GWPP mitigation system in which a plant by-product was identified above the lower level of detection. The four releases contained only tritium with no plant by-product gamma emitters identified.
  • Temporary groundwater mitigation was performed during all four quarters of 2020 from select monitoring wells that indicated elevated tritium concentrations. For 2020, there were forty-three batch releases from the temporary mitigation system. All releases contained only tritium with no plant by-product gamma emitters identified.
  • Continuous monitoring with gamma sensitive radiation detectors is provided for plant service water systems. For the year 2020, there were no instances where these liquid radiation monitoring systems were inoperable on an active release point for a period of 30 (contiguous) days or more. (ODAM-DODAM OLCO 6.1.1.1 A.2)
  • Sewage effluent releases are sampled under the auspices of the Groundwater Protection Program. The sewage sample results from on-site laboratory are included in Attachment 1A.

All other Groundwater Protection Program analyses and results can be found in the Duane Arnold Energy Center 2020 Annual Radiological Environmental Operating Report.

Page 9

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF GASEOUS EFFLUENTS There were no radioactive gaseous batch releases from the Duane Arnold Energy Center during this report period. All gaseous effluent releases were continuous and resulted in a small fraction of the 10 CFR 50, Appendix I dose limits.

For all release points, quarterly average gross alpha concentration of radioactivity measured less than 4.1 OE-09 µCi/cc.

There were no abnormal releases of gaseous effluents during the period.

Table 1A - Gaseous Effluents - Summation of All Releases 1st 2nd 3rd 4th Est. Total Units Quarter Quarter Quarter Quarter Error, %

Fission and Activation Gases

1. Total Release Ci 0.00E+OO 6.38E+01 6.08E01 0.00E+OO 1.60E+01 I
2. Average Release Rate for Period µCi/sec O.OOE+OO 8.11E+OO 7.65E+OO 0.00E+OO
3. Percent of Applicable Limit  % * * *
1. Total 1*131 Ci 1.66E-06 2.55E-04 1.12E-05 3.45E-07 1.80E+01 I
2. Average Release Rate for Period µCi/sec 2.11 E-07 3.24E-05 1.41 E-06 4.34E-08
3. Percent of Applicable Limit  % * * *
  • Particulates
1. Total Particulates w/ half-life >8 days Ci 7.05E-06 6.22E-05 6.0BE-05 3.63E-05 1.80E+01 I
2. Average Release Rate for Period µCi/sec 8.97E-07 7.91E-06 7.65E-06 4.56E-06
3. Percent of Applicable Limit  % * * *
1. Total Release Ci 5.71E+OO 8.06E+OO 1.44E+OO 1.42E+OO 1.60E+01 I
2. Average Release Rate for Period µCi/sec 7.26E-01 1.03E+OO 1.82E-01 1.79E-01
3. Percent of Applicable Limit  % * * *
1. Total Carbon-14 Ci 2.39E+OO 2.06E+OO 0.90E+OO 0.00E+OO
2. Average Release Rate for Period µCi/sec 3.0?E-01 2.62E-01 1.13E-01 0.00E+OO
3. Percent of Applicable Limit  % * * * *
  • Applicable limits have been removed from the Technical Specifications. The comparison to ODAM limits is contained in the Radiological Impact on Man section of this report.

Page 10

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Table 1 B - Gaseous Effluents by Quarter ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT {2020)

GASEOUS EFFLUENTS BY CALENDAR QUARTER (Curies)

Nuclides Released Unit 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter

1. Fission qases krypton-85 Ci ND 1 ND ND ND krypton-85m Ci ND 9.26E-01 3.69E-01 ND krypton-87 Ci ND 7.64E-01 5.92E-01 ND krypton-88 Ci ND 8.68E-01 4.38E-01 ND xenon-131m Ci ND ND ND ND xenon-133 Ci ND 7.57E+OO 5.53E+01 ND xenon-133m Ci ND ND ND ND xenon-135 Ci ND 3.75E+01 5.51E-01 ND xenon-135m Ci ND 1.05E+01 1.03E+OO ND xenon-138 Ci ND 5.73E+OO 2.48E+OO ND argon-41 Ci ND 3.25E-04 6.08E+01 ND Total for period Ci ND 6.37E+01 O.OOEOO O.OOEOO
2. Iodines iodine-131 Ci 1.66E-06 2.55E-04 1.12E-05 3.45E-07 iodine-133 Ci 8.59E-06 4.97E-05 4.02E-06 O.OOE+OO iodine-135 Ci ND ND ND ND Total for period Ci 1.03E-05 3.05E-04 1.53E-05 3.45E-07
3. Particulates strontium-89 er 1.86E-06 1.24E-05 9.12E-06 4.59E-07 strontium-90 Ci 5.13E-07 1.67E-06 1.98E-08 ND cesium-134 Ci ND ND ND ND cesium-137 Ci ND ND ND ND barium-lanthanum-140 Ci ND 2.3E-06 1.08E-06 ND chromium-51 Ci ND ND ND ND cobalt-58 Ci ND ND 8.26E-08 3.27E-07 cobalt-60 Ci ND 2.56E-06 6.24E-06 1.69E-05 manganese-54 Ci 2.40E-06 1.29E-05 1.73E-05 1.68E-05 iron-55 Ci 2.28E-06 3.04E-05 2.65E-05 ND iron-59 Ci ND ND ND ND nickel-63 Ci ND 2.56E-08 7.88E-08 ND zinc-65 Ci ND ND 4.55E-07 1.80E-06 zinc-69m Ci ND ND ND ND Total for period Ci 7.05E-06 6.22E-05 6.09E-05 3.63E-05
4. Tritium Ci 5.71 E+OO 8.06E+OO 1.44E+OO 1.42E+OO Tritium Total Ci 5.71E+OO 8.06E+OO 1.44E+OO 1.42E+OO
5. Carbon-14 Ci 2.39E+OO 2.06E+OO 9.0E-01 O.OOE+OO Carbon-14 Total Ci 2.39E+OO 2.06E+OO 9.0E-01 O.OOE+OO
1. ND indicates the radionuclide was not identified in any samples using instrumentation that meets the lower limit of detection as required by the DAEC Offsite Dose Assessment Manual.

Page 11

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Table 1C - Gaseous Effluents by Release Point ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT (2020)

GASEOUS EFFLUENTS BY RELEASE POINT (Curies)

RELEASE POINT: OFFGAS STACK REACTOR BUILDING TURBINE BUILDING LLRPSF RELEASE HEIGHT: 328 FEET 156 FEET 90 FEET 65 FEET RELEASE MODE: ELEVATED WAKE SPLIT *.... -~~II *-

--~*

...,T argon-41 3.25E-04 ND 1 ND ND barium-140 3.38E-06 ND ND ND cesium-134 ND ND ND ND cesium-137 ND ND ND ND chromium-51 ND ND ND ND cerium-141 ND ND ND ND cobalt-58 ND 4.10E-07 ND ND cobalt-60 ND 2.53E-05 ND 4.00E-07 iodine-131 6.32E-05 1.43E-04 6.16E-05 ND iodine-133 2.09E-05 2.48E-05 1.66E-05 ND iron-55 3.45E-06 5.75E-05 ND ND iron-59 ND ND ND ND krypton-85 ND ND ND ND krypton-85m 1.30E+OO ND ND ND krypton-87 1.36E+OO ND ND ND krypton-88 1.31E+OO ND ND ND manganese-54 1.79E-06 4.72E-05 ND 3.63E-07 nickel-63 ND 1.04E-07 ND ND strontium-89 1.26E-05 6.20E-06 4.44E-06 5.97E-07 strontium-90 2.20E-06 ND ND ND tritium 2.60E+OO 6.51E+OO 7.51E+01 3.50E-02 xenon-131m ND ND ND ND xenon-133 6.29E+01 ND ND ND xenon-133m ND ND ND ND xenon-135 1.30E+01 2.49E+OO 1.95E-01 ND xenon-135m 1.15E+01 ND ND ND xenon-138 8.21E+OO ND ND ND zinc-65 ND 9.04E-07 ND 1.35E-06 zinc-69m ND ND ND ND carbon-14 2 5.29E+OO - - -

1. ND means that the radionuclide was not identified in any samples using Instrumentation that meets the lower limit of detection as required by the DAEC Offsite Dose Assessment Manual.
2. Carbon-14 release was estimated using methods of the EPRI document, "Estimation of Carbon-14 in Nuclear Power Plant Gaseous Effluents"; Report 1021106, issued December 2010.

Page 12

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTNE MATERIAL RELEASE REPORT Estimated Release of Gaseous Carbon-14 The estimate of gaseous carbon-14 (C-14) released from the Duane Arnold Energy Center was derived using the EPRI document, "Estimation of Carbon-14 in Nuclear Power Plant Gaseous Effluents.", Report 1021106, issued December 2010. The site-specific source term for the DAEC was estimated using the proxy generation rate values from Table 3-1 and the actual 2020 power history for the site. Power production permanently ceased on August 10, 2020.

The total amount of C-14 released from the site in 2020 was estimated to be 5.29 curies.

Using the dose calculation methodology from Regulatory Guide 1.109, the resultant maximally exposed receptor organ from C- 14 is the bone of a child, located 1,760 meters towards the North. The dose is 2.14E-01 mrem (0.000214 rem/yr). This is a fraction of the 1 mrem annual whole-body dose received to the average US citizen from natural occurring carbon-14, primarily generated through cosmogenesis in the terrestrial biosphere. (

Reference:

National Council of Radiation Protection Report 94), Exposure of the Population in the United States and Canada from Natural Background Radiation.")

Gaseous Effluents Summary Trend in Curies Per Year Excluding Carbon-14 DAEC Gaseous Effluents curies

- -o- - Noble Gas 1.E-1 ~ ---1 1--+---1--+--1-- .a.. -Panlculatu 1.E-4

- . -1001001 Page 13

DUANE ARNOLD ENERGY CENTE:R 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT The following graphs show gaseous effluent dose trends for monthly particulate and iodine, monthly gamma, and monthly beta.

DAEC Particulates & Iodine Trend nu em 1.flUl O / - -- - - - - - -- -- - - - - -- - - -- - - -

  • * *1l '4l - - - - - - - - - - - - -- - - - - - - - - - --------.
  • *, f tl} _ __ , ._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ __ __

1~01 I ~--1----------------------.

I Wfu inocoJ ----t- - -- - - - - - -- - - - - - - - - - - -

~ 1 '4' 1ltll .----+----------~------------:

h.ll<J f ~i - - - ! - - - - -- - - - - - - - - - - - - - - - - -

4 4'Utos ~1--1----------------------

mmd DAEC Gamma Dose Trend 1 60£ -02 I

t lOf-02 I 00 [-02 a OOt-03 I

I l.~L I.

l1l~LILtl ~ht. . .,

l 00 £-03 - I L  ; i,1 I *-**-* l

  • _LI.Li_

Page 14

DUANE ARNOLD ENERGY CENTER l

2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT DAEC Beta Dose Trend mrad UOl-Ol I

I 60E-()2 I I 40t-0 2 .

I 1 iot-oz. - I I OOC-02 a oac-01 ---i

_J

& ()0[-0]

  • I OOC-Cl i OOE-Ol -----

1 1.IJ.l~1 .l1.1l1l hlL1 l l~ul. .,f, _,d,.Jl~1 lt.1l.1 1 1 ,..........-..l.. ... I. .. ** --* -~

ul ........J ....._. . _ _ ...-!"""

Comparative analysis of 2000-2020 gaseous effluent monthly data indicates the 2020 gaseous effluent release trends continue to be less than the 10 CFR 50 Appendix I limits.

Page 15

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF LIQUID EFFLUENTS Liquid effluent release in the form of service water from the facility was continuous during the period. No reactor by-product radionuclides were identified in samples from service water or sewage effluent. There were twenty liquid batch releases from the radioactive waste system and batch releases contained tritium, Manganese-54, Cobalt-60, and Cesium-137.

There were forty-seven liquid releases from groundwater mitigation. The identified only identified plant by-product released was tritium. As noted earlier, four continuous liquid releases were from groundwater mitigation system, and forty-three batch releases were from temporary groundwater mitigation system or a "Clean" system.

Table 2A - Liquid Effluents - Summation of All Releases 1st 2nd 3rd 4th Est. Total Quarter Quarter Quarter Quarter Error, %

Fission and Activation Gases

1. Total Release (not including Tritium, Ci O.OOE+OO O.OOE+OO O.OOE+OO 8.03E-06 2.00E+01 gases, alpha)
2. Average Release Rate for Period µCi/ml O.OOE+OO 0.00E+OO O.OOE+OO 1.81E-11
3. Percent of Applicable Limit  % * * *
1. Total Release Ci 7.22E-03 2.64E-02 3.49E-02 3.89E+OO 2.00E+01 I
2. Average Release Rate for Period µCi/ml 1.70E-08 1.94E-08 2.41 E-08 8.75E-06
3. Percent of Applicable Limit  % * * *
  • Volume of Water Released (Prior To Dilution) Liters 1.25E+06 2.25E+06 1.68E+06 3.64E+06 Volume of Dilution Water Used During Period Liters 4.25E+08 1.36E+09 1.45E+09 3.30E+09
  • Applicable limits have been removed from the Technical Specifications. The comparison to ODAM limits is contained in the Radiological Impact on Man section of this report.

Page 16

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Table 28 - Liquid Effluents ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT (2020)

LIQUID EFFLUENTS (Curies)

Nuclides Released Unit 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter strontium-89 Ci ND 1 ND ND ND strontium-90 Ci ND ND ND ND cesium-134 Ci ND ND ND ND cesium-137 Ci ND ND ND 6.16E-07 iodine-131 Ci ND ND ND ND cobalt-58 Ci ND ND ND ND cobalt-60 Ci ND ND ND 3.31 E-06 iron-55 Ci ND ND ND ND iron-59 Ci ND ND ND ND zinc-65 Ci ND ND ND ND manganese-54 Ci ND ND ND 4.10E-06 chromium-51 Ci ND ND ND ND zirconium-niobium-95 Ci ND ND ND ND molybdenum-99 Ci ND ND ND ND technetium-99m Ci ND ND ND ND barium-lanthanum-140 Ci ND ND ND ND cerium-141 Ci ND ND ND ND other Ci ND ND ND ND tritium Ci 7.22E-03 2.64E-02 3.49E-02 3.87E+OO xenon-133 Ci ND ND ND ND xenon-135 Ci ND ND ND ND

1. ND means that the radionuclide was not identified in any samples using instrumentation that meets lower limit of detection as required by the DAEC Offsite Dose Assessment Manual.

Page 17

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT DAEC Liquid Effluents Trend mrem 100[*02 6.00t-02 S.OOE*02 l .O~E *02

~-0~[ *02 l.00[*02 -- - -

I l.OOE*Ol

  • ..--*** ...... , __._.._ .. *- * - **-* L.Lt:~ _ _JI Note: 2016 to October 2020 DAEC offsite dose from liquid effluents is due to mitigation of tritiated groundwater.

Page 18

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF RADIOACTIVE SOLID WASTE A total of seven solid radioactive waste shipments occurred during 2020.

Five shipments of spent resin were made in 2020. Spent resin in poly liners were shipped for direct burial at Energy Solutions, located in Clive, Utah at their Containerized Waste Facility (CWF). All five shipments contained resin from the condensate system, and all were transported by highway.

Two shipment of Dry Active Waste (DAW) were shipped for processing and subsequent burial in 2020. This single shipment was sent to Energy Solution Bear Creek processing facility for sorting followed by shipping to Energy Solutions Clive, Utah facility for burial. The DAW was shipped by highway.

There were no shipments of liquid radwaste in 2020.

Page 19

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Shipments in 2020 Listed below are tables summarizing the Duane Arnold Energy Center's generation of Radioactive Solid Waste for the period of January 1, 2020 through December 31, 2020.

Shipments Made To Burial Facilities in 2020 NO. VOLUME VOLUME ACTIVITY SHIPMENTS (ft3) (m3) (curies) 5 659.7 18.68 155.93 Energy Solutions, Containerized Waste Facility and Bulk Waste Facility Clive, Utah See Table 3A below for Major Nuclides Shipments Made To Processing Facilities in 2020 NO. VOLUME VOLUME ACTIVITY SHIPMENTS (ft3) (ma) (curies) 2 4,200 7.75 0.746 DESTINATION Energy Solutions Bear Creek Facility In Oakridge TN The solid waste was subsequently delivered to Containerized Waste Facility and Bulk Waste Facility Clive, Utah.

See Table 3B below for Major Nuclides Total Solid Waste Disposition for 2020 VOLUME VOLUME (ma) ACTIVITY (curies)

(ft3) 4,860 137.61 156.8 4,860 137.61 156.8 SOLIDIFICATION AGENT: None MODE OF TRANSPORTATION: Exclusive-Use Vehicle (Trucks).

IRRADIATED COMPONENTS: There were no shipments of irradiated components or nuclear fuel in 2020.

See Table 3C below for Annual Summary of Major Nuclides Waste Classification per 10 CFR 61 NUMBER OF SHIPMENTS IN 2020 A-Unstable 7 A-Stable 0 B 0 c 0 s*1te H"1storicaIC omparison Year Volume Buried(ft 3l Activitv ICil 2008 5.42E+03 134 2009 1.16E+04 58 2010 1.14E+04 23 2011 7.26E+03 324 2012 2.48E+04 58 2013 7.19E+03 52 2014 2.70E+04 33 2015 6.68E+03 48 2016 1.02E+03 43 2017 1.08E+04 156 2018 1.59E+04 115 2019 2.78E+03 171 2020 4.86E+03 157 Page 20

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Summary of Radioactive Solid Waste ~Spent Resin January 1, 2020 - December 31, 2020 Table 3A Spent Resin Major Nuclide Composition H-3 9.61E+OO 5.07E+OO 1.52E+01 2.07E+01 Illf~~~~~~~~~

5.05E+01 0.032%

C-14 1.45E+01 7.65E+OO 1.63E+01 1.35E+OO 3.98E+01 0.025%

K-40 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Cr-51 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Mn-54 5.97E+03 3.17E+03 2.10E+03 1.69E+01 1.13E+04 7.219%

Fe-55 3.70E+04 1.95E+04 2.11 E+04 1.10E+03 7.87E+04 50.465%

Co-57 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Co-58 3.22E+02 1.75E+02 1.09E+02 O.OOE+OO 6.06E+02 0.389%

Ni-59 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Fe-59 5.31E+01 2.94E+01 1.82E+01 O.OOE+OO 1.01E+02 0.065%

Co-60 4.73E+03 2.50E+03 3.37E+04 7.29E+03 4.82E+04 30.892%

Ni-63 2.39E+02 1.26E+02 1.36E+03 9.93E+01 1.82E+03 1.169%

Zn-65 7.99E+03 4.25E+03 2.64E+03 O.OOE+OO 1.49E+04 9.543%

Sr-89 1.40E+OO 7.68E-01 4.77E-01 O.OOE+OO 2.65E+OO 0.002%

Sr-90 6.90E-01 3.64E-01 3.98E+OO O.OOE+OO 5.03E+OO 0.003%

Sr-91 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Zr-95 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Nb-95 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Tc-99 8.63E+OO 4.55E+OO 1.06E+01 6.09E+OO 2.98E+01 0.019%

A~-110m O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sn-113 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sb-124 6.35E+OO 3.46E+OO 2.15E+OO O.OOE+OO 1.20E+01 0.008%

Sb-125 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

1-125 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.00E+OO 0.000%

1-129 1.69E-01 8.91E-02 2.28E+OO 5.06E-02 2.58E+OO 0.002%

Cs-134 O.OOE+OO O.OOE+OO 0.00E+OO O.OOE+OO O.OOE+OO 0.000%

Cs-137 5.14E+01 2.71E+01 4.08E+01 6.67E+OO 1.26E+02 0.081%

Ce-144 3.23E+01 1.72E+01 7.79E+01 7.32E+OO 1.35E+02 0.086%

PU-238 O.OOE+OO O.OOE+OO O.OOE+OO 7.28E-02 7.28E-02 0.000%

Am-241 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

'~5;:6~E>ii<i4'~ ~,Z,:ga:i:,ef4~ ~6~h'f8£0fi~ ,'8~5§'.Ef,os~ '~H~~66~~o5f , ~-1<>>o~odo/J-r:~

1:>,, """ ,cc I '!EO.tl:llS'°Z'c~

Note: H-3, C-14, Tc-99 and 1-129 are required to be manifested per 10 CFR 20, Appendix G.

H-3, Tc-99 and 1-129 represent Minimum Detectable Activity (MDA) values These three nuclldes are calculated from uCi/cc on manifest by the material volume Page 21

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Summary of Radioactive Solid Waste - Dry Active Waste January 1, 2020 - December 31, 2020 Table 38 Dry Active Waste Major Nuclide Composition

p>rfocipfe-S.* *ifaf<QTR~* :zncJ.QTR~( :3rct~t".l+R~:. *;;/fffl;OTR *~-Ioti'llC.*-***. Percent.>*'

it-J~cffa~' ;~ *g_trm-cW-;-} :c;,1mcfi'.-,_ "2*rrnaf5'c::": *::-.imcr)--~). \~*crne1r~= .~A6unaa6bif' H-3 O.OOE+OO 3.01 E-01 4.87E-01 O.OOE+OO

  • 7.88E-01 0.106%

C-14 O.OOE+OO 2.90E-02 4.69E-02 O.OOE+OO 7.59E-02 0.010%

K-40 O.OOE+OO O.OOE+OO O.OOE+OO 0.00E+OO O.OOE+OO 0.000%

Cr-51 O.OOE+OO 2.78E+OO 4.50E+OO O.OOE+OO 7.28E+OO 0.976%

Mn-54 O.OOE+OO 1.42E+01 2.30E+01 O.OOE+OO 3.72E+01 4.985%

Fe-55 O.OOE+OO 2.17E+02 3.51 E+02 O.OOE+OO 5.68E+02 76.118%

Co-57 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Co-58 O.OOE+OO 6.30E-01 1.02E+OO O.OOE+OO 1.65E+OO 0.221%

Ni-59 O.OOE+OO 1.26E-01 2.04E-01 O.OOE+OO 3.30E-01 0.044%

Fe-59 O.OOE+OO 8.39E-01 1.36E+OO O.OOE+OO 2.20E+OO 0.295%

Co-60 O.OOE+OO 3.41 E+01 5.52E+01 O.OOE+OO 8.93E+01 11.967%

Ni-63 O.OOE+OO 1.36E+01 2.21 E+01 O.OOE+OO 3.57E+01 4.784%

Zn-65 O.OOE+OO 1.01 E+OO 1.64E+OO O.OOE+OO 2.65E+OO 0.355%

Sr-89 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sr-90 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sr-91 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Zr-95 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Nb-95 O.OOE+OO 3. 75E-02 6.07E-02 O.OOE+OO 9.82E-02 0.013%

Tc-99 0.00E+OO 2.15E-02 3.49E-02 O.OOE+OO 5.64E-02 0.008%

Ag-110m O.OOE+OO 0.00E+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sn-113 O.OOE+OO 0.00E+OO O.OOE+OO 0.00E+OO O.OOE+OO 0.000%

Sb-124 0.00E+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Sb-125 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

1-125 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.00E+OO 0.000%

1-129 0.00E+OO 6.95E-03 1.12E-02 O.OOE+OO 1.82E-02 0.002%

Cs-134 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

Cs-137 O.OOE+OO 1.33E-01 2.16E-01 O.OOE+OO 3.49E-01 0.047%

Ce-144 O.OOE+OO 1.95E-01 3.16E-01 O.OOE+OO 5.11E-01 0.068%

Pu-239 O.OOE+OO O.OOE+OO 0.00E+OO O.OOE+OO O.OOE+OO 0.000%

Am-241 O.OOE+OO 0.00E+OO O.OOE+OO O.OOE+OO O.OOE+OO 0.000%

.Tot~i~K > 6.606+00 2l85Eto2~ 4.618+/-62: *o.OOE-f-60 'i.46E+o2 * *,100:00%' ,

Note: H-3, C-14, Tc-99 and 1-129 are required to be manifested per 10 CFR 20, Appendix G.

H-3, Tc-99 and 1-129 include Minimum Detectable Activity (MDA) values These three nuclides are calculated from uCi/cc on manifest by the material volume Page 22

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Summary of Radioactive Solid Waste - Annual Summary January 1, 2020 - December 31, 2020 Table 3C Radwaste Annual Summary Major Nuclide Composition

~ ..-_-;<--- ~ -*-.. :."~: -_ -- ',_:*--<?<:<_'-

  • 'Nuclide ... .. .:

Curi.es .

H-3 5.13E+01 C-14 3.98E+01 K-40 O.OOE+OO Cr-51 7.28E+OO Mn-54 1.13E+04 Fe-55 7.93E+04 Co-57 O.OOE+OO Co-58 6.08E+02 Ni-59 3.30E-01 Fe-59 1.03E+02 Co-60 4.83E+04 Ni-63 1.86E+03 Zn-65 1.49E+04 Sr-89 2.65E+OO Sr-90 5.03E+OO Sr-91 O.OOE+OO Zr-95 O.OOE+OO Nb-95 9.82E-02 Tc-99 2.99E+01 Ag-110m O.OOE+OO Sn-113 O.OOE+OO Sb-124 1.20E+01 Sb-125 O.OOE+OO 1-125 O.OOE+OO 1-129 2.60E+OO Cs-134 O.OOE+OO Cs-137 1.26E+02 Ce-144 1.35E+02 Pu-238 7.28E-02 Am-241 O.OOE+OO

  • * ***. Total \ .-io:

<<1~#1:+02~

1:', ..  :, '_ ', *- .\,':

Page 23

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT RADIOLOGICAL IMPACT ON MAN The annual offsite radiation dose to a member of the public was determined by assessment of environmental dosimetry results, calculations based on monitored effluent releases, and estimates of gaseous carbon-14 releases.

Dose Contribution from Direct Radiation Direct radiation dose from the operation of the DAEC was captured by TLDs placed at locations in the surrounding environment as described in the ODAM-DODAM. Pre-operational and 2020 TLD results were evaluated with a paired difference statistical test. The evaluation concluded that there were no significant differences in the TLD populations for the 0.5-mile, 1 mile and Control TLD populations. No measurable dose due to the operation of the DAEC was detected by environmental TLDs in 2020. In addition, compliance with 40 CFR 190 limits of 25 mrem whole body and 75 mrem thyroid is demonstrated in the Duane Arnold Energy Center 2020 Annual Radiological Environmental Operating Report, subsections "Ambient Radiation (TLDs)"

and "ISFSI Facility Operations Monitoring".

Estimated Offsite Dose from Effluent Releases The contribution of dose to a member of the public most likely to be exposed from liquid and gaseous effluent releases was calculated using the MIDAS computer program in accordance with the ODAM-DODAM. The calculation methods follow those prescribed by Regulatory Guide 1.109, "Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I".

Dose to members of the public from gaseous carbon-14 releases is calculated separately and is described below and on page 13.

Results of the MIDAS dose calculations are below:

1.) There were sixty-seven batch and continuous releases of radioactive material to liquid effluents in 2020. The maximum dose from tritiated liquid releases to a child's total body was 0.0000328 rem and maximum organ dose to a child's liver was 0.0000329 rem.

2.) The maximum gamma air dose from noble gases released was 0.0000157 rad located at 481 meters towards the South-Southeast from plant centerline.

3.) The maximum beta air dose from noble gases released was 0.0000181 rad at 481 meters towards the South-Southeast from the plant centerline.

4.) The whole-body dose equivalent to the hypothetical maximally exposed individual from noble gases was 0.0000053 rem at 805 meters towards the West from the plant centerline.

5.) The skin dose equivalent to the hypothetical maximally exposed individual (child) from noble gases was 0.0000096 rem at 805 meters towards the West from the plant centerline.

Page 24

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT 6.) The hypothetical maximally exposed organ due to airborne iodines and particulates with half-lives greater than eight days (excluding carbon-14) was 0.00000456 rem to the thyroid of a child at 805 meters towards the West from the centerline of the plant.

7.) The hypothetical maximally exposed organ due to airborne carbon-14 was 0.000214 rems to the bone of a child located 1, 760 meters to the North from the centerline of the plant.

CONCLUSION The contribution of dose to a member of the public most likely to be exposed from liquid and gaseous effluent releases was calculated using the MIDAS computer program in accordance with the ODAM-DODAM and site procedures. The calculated doses for gaseous and liquid effluent releases are below the regulatory limits stated in 10 CFR 50, Appendix I and in 40 CFR 190.

Estimated Maximum Offsite Individual Doses for 2020 Type Age Group Distance Direction Dose or Dose Equivalent Annual 10 CFR 50, (meters) lmreml Appendix I "Limit" Direct Radiation (as measured bv TLDs)

None

  • Liauid Releases Whole Bodv Dose Child ot J SE 0.0328 mrem 3 mrem Oraan Dose Child - Liver D1 SE 0.0329 mrem 10 mrem Noble Gas Gamma Air Dose 481 SSE 0.0157 mrad 10 mrad Beta Air Dose 481 SSE 0.0181 mrad 20 mrad Whole Bodv All 805 w 0.00530 mrem 5mrem Skin Child 805 w 0.00960 mrem 15 mrem Particulates & Iodines Organ Dose Child - Thyroid 805 w 0.00456 mrem 15 mrem Carbon 14 Organ Dose Child- Bone 1,760 N 0.214 mrem 15 mrem
  • There is no Appendix I limit for direct radiation. Compliance with 40 CFR 190 limits of 25 mrem whole body and 75 mrem thyroid is demonstrated in the Duane Arnold Energy Center 2020 Annual Radiological Environmental Operating Report, subsections "Ambient Radiation (TLDs)"

and "ISFSI Facility Operations Monitoring".

Receptor location is aquatic pathway at Cedar River. See ODAM-DODAM, Figure 3-2.

Page 25

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF METEOROLOGICAL DATA The following pages are a summation of meteorological data accumulated during the 2020 calendar year by the MIDAS software at the Duane Arnold Energy Center.

Greater than 90% data recovery was obtained for combined wind speed, delta temperature and wind direction. The table below summarizes 2020 data collection results:

Elevation and Sensors Joint Recovery Valid Data 10-meter Wind Direction Wind Speed 100%

Delta Temp 50-meter Wind Direction Wind Speed 99.3%

Delta Temo The following pages contain wind rose plots and stability class summary tables for the specified sensor heights (33 feet or 156 feet). Joint Frequency tables for each of the individual stability classes are maintained on site and are available upon request.

Page 26

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT Sta~lllty Class Data 33' Joint Fl'equenc.y Dlsh'lbulion Hours at Each Wind Spec(i and Dii'wion To1al Ptrlod  :\11 BDUl'S Ptriod ofRtrord "' 01/Pll202000.00* 011011202100;00 Ile\*~tlo111 Spud: WS33 Dln<tion: WD33 Lnpu: DELT S1obillty Clm: ALI,. Della TC!Up eorur~

\Vlnd 'Spe~d (mph)

Wh11I Qlrmloo U..3.5 3.6-1.5 7.6-ll.5 12.6-1~.5 18.6-:?1.S >ZM Tola!

N .S3 122 SI 16 1 l 274 NI'l'E 83 190 140 47 3 I -164 i\'E 127 2U 128 13 0 4 504 ENE 1 ~2 163 Ji 3 0 l 326 E 106 176 ll J 0 0 314 ESE 96 2~5 62 3 I 3 -100 SE 2.li 329 6:S 0 0 2 60S SSl: ZS3 351 63 I 2 5 70.5 s 326 465 209 34 1 2 1037 SSW 2-1~ :U2 !OS 44 j I 623 5'\' IS& 185 S5 15 1 4 448 WSW l .S~ q9 .61 17 7 0 370 w 99 !OS 110 40 25 7 389 Wl\"\Y 6-1 1Sl t48 93 47 5 538 i\"W 42 267 311 13$ 14 2 Ti l 1'1'1\' 39 131 2S} ll3 7 2 575 Total 2240 3486 1893 57~ 112 40 8346 Calm. Hou11 1101 Indudtd a~Ol't fer: Total Ptliod Allllours 3;9 Variable Dliwlon Houn tor: ToilllPulod AUHoun 0 IunUd Houn for: Tola! Pt1irid AllH~un 60 l\11111br1* ofV;illd Houn for this Table Tot1l l'trlod AU}Joun 8346 I otal Hours for the Prriod: 8785 Wind Rose Data 33' WIND ROSE

('M ~S FF\OIAJ N

1' D1111: PEJIO'lll CN.J.15 (NOT INQ.UDEO IN FlOl) tGX Sle~Oela: 1/1/2020 00:00 End Oalu: 1/1/2021 00:00

- Svnso*~ Soluct* d Y/$3)

WDll i: 0 ~~b $Fil(b 1..m llWI i&MPll ii WlllO SPEED LESS TlfAll 7.51.lPli o WIHO Sf'E£D l.£SS llWI tl.$ Hl'll

  • \lllllOSFHOGRfATEA TIWI 12Jl"4flt Wlnct Rose (Direction From)

Page 27

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REP.ORT Stability Class Data 156' Joint Frequency Distribution Hours at Each Wind Spe~d and Dirtclion Told Period All Houri Pnlod ofRtco1*d

  • 0 1101/2 020 00.00
  • 01 10112021 00:00 Elm1tion: Speed: WSIS6 Dlr<<cJou: WDIS6 Lap1r: DEL T Srablllcy Clm: ALL Ddti T'111pezature Wind Speed (ruph)

Wind Dlrtctlon 1.1.J.~ 3.6-7.5 7.6-U.S H.6-18.5 18.6*Z~.S >lU Total N 46 105 128 62 19 ... 3!S4 NNE 33 92 167 IHI 29 0 450 l\"E 31 132 196 100 11 0 471)

El\"E 23 121 120 39 I 0 304 E 31 121 14~ 28 1 0 325 ESE 33 13i 193 36 3 0 .IOi SE 50 301 22S 2S 0 0 601 SSE .J } 2:56 381 111 26 0 815 s 43 187 .m 306 85 1.2 l059 SSW 51 1S:S 195 130 .\6 24 631 SW 42 172 134 70 22 15 -151 wsw 26 129 105 5-1 I~ 11 337 w 28 SIS 136 95 31 3() 406 WNW 26 128 lil 127 62 54 569

!\'W 21 1'15 291) 224 g3 16 185

.NNW 30 ID 2S8 223 54 6 716 Total m 2.\12 3305 176S .JS ~ In 870-1 Cahn Hou l's uot Indudtd abo\'t .tor: Toi QI Ptriod AUHoun 21

\'arlable. Dltwion Houn for: Toi al Prriod AU Hours 0 InnUd Haun for: J ot1l Prriod AUHoui*s 60 Nu11bH' of \'aUd Hou1:s rof thh Table TotalPuiod ..\JIHoun 8704 Tot1l Ho11n for the Period: *sm Wind Rose Data 156' WINO AOSE

('iytNDSFFIOM)

N

  • ~

0.00,PCACctll CIUIS

(~iOT INctUOED IN PLOn lG lt G111t10all1 ! l/lf'i.020 UO:OO End Colo: l/l/iD21 00:00 Logund A y,ftl05Pl!EO U:SS llWl:l~MPl l

  • o 1o.111omeom~nw11.sMP11

\WI D~PElO 1~5lit.Ill12.~MPll

  • \\HID SPEEO unEAtrn (HAN IU llPll Wind Rose (Direction from)

Page 28

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF GROUNDWATER PROTECTION INITIATIVE ISSUES The Duane Arnold Energy Center has committed to the Nuclear Energy lnstitute's Industry Groundwater Protection Initiative - NEI 07-07. Per NEI 07-07, the following information is listed:

  • Groundwater Protection Program (GWPP) samples were collected and analyzed in accordance with the requirements and guidance of the site procedures.
  • The GWPP is a component of the Duane Arnold Energy Center's Radiological Environmental Monitoring Program (REMP). As such, REMP and GWPP sampling and analysis except for sewage effluent results can be found in the Duane Arnold Energy Center 2020 Annual Radiological Environmental Operating Report.
  • Presented in Attachment 1 are only sewage effluent analysis lower level of detection results as determined by the site laboratory. No plant by-products were identified in sewage samples.
  • Groundwater Protection Program details can be found in ODAM-DODAM, Table 6.3-2, Attachment 2, and sampling locations can be found in ODAM-DODAM, Table 5-1.

Specifically, GWPP sample locations are identified by station number, GWPP station location, and sample type. A simplified map of environmental sample locations can be found in the ODAM-DODAM, Figure 5-1 and Figure 5-2.

  • Analysis of GWPP results indicates a tritiated groundwater plume remains confined to the protected area and adjacent owner-controlled property at a depth 25 feet or less. Tritiated groundwater has not been identified outside the owner-controlled area. Tritium has not been identified in any drinking water well. In accordance with standards set forth in the ODAM-DODAM, tritiated groundwater is discharged and released as a liquid effluent.
  • The Duane Arnold chemistry laboratory participates in Radiochemistry Cross Check Program with the firm Eckert & Ziegler Analytics from Atlanta, GA. The cross-check program results are available upon request.
  • The vendor laboratory providing results from the Duane Arnold Energy Center's REMP and GWPP sampling is Environmental Inc. Midwest Laboratory of Northbrook, IL. The Environmental Inc. laboratory participates in several cross-check programs. These cross-check program results are presented in the 2020 Duane Arnold Energy Center Annual Radiological Environmental Operating Report or by request.

Page 29

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL AADIOACTIVE MATERIAL RELEASE REPORT

  • The following graph shows the volume of groundwater released and tritium concentration trend for 2020. The data source is from the permanent groundwater mitigation system. The tritiated groundwater trend Indicates a consistent absence of tritiated groundwater above 51000 pCi/L for all of 2020. The tritiated groundwater spikes in March 2020 and October-November 2020 are due to equipment repairs and enhancements, which may have enabled temporary increase of tritiated groundwater followed by rapid decline once mitigation operations resumed.

2020 Volume of Groundwater Extracted-Released and Tritium Concentration Trend

- - h~rtrt l on Well Reins~ (TotnlGnllons) - TrltlumCancentrntlon (PC{L}

Concl!ntrat!on J5DE*07.,-~~- :..ooo 4,500 300E*07 -t------~-------------------1

__... ... ~ ~ -

2.50E* 07

~~

~.500 3,000 lOOE*07 1--------11 ------------~-------1 2,500 1.SOh07 1- -- - 1- 1 ----~---------11------

2,000

_ __ _ _ , 1,500 1.00Eo07 . - -- - - - *- -!- -- - -- - - - ---- --*-*-. -

1,000 S 00£-t06 1--- - - -1 500 0 COf,00 i.--- - - -*-- 0

,," ".... <:> n

... ..."' g

.."' . ;;;-.. .$ ~

0

~ Ii? 0 ~

0 0

~  !<! ~ ~ ~ 0 l3 !::! C'l

" 0 ~

ro

!:! t! ~

..."' ... "' cs...~ "'...

~  ;:; ~ ~ *~

~.

~ :a:

~

.., ,.,c:

~ ~ :it

.... !!!. ~  ::; 3: ~ ~

§  :?

~

~ iii"

~

N j:: ~

0

~

- ~ ~

Analysis: the variation in tritium concentration is a function of individual extraction well gallons per minute (GPM) of discharge, simultaneous operation , and the release point.

Page 30

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF CHANGES TO THE 0FFSITE DOSE ASSESSMENT MANUAL (ODAM)

Before implementation of the following described changes, a review was performed to validate that the levels of radioactive effluent control required by 10 CFR 20.1302, 40 CFR 190, 10 CFR 50.36a, and 10 CFR 50, Appendix I were not affected. The review also verified that the changes did not adversely impact the accuracy or reliability of effluent dose or set point calculations.

Revision 41 ~ Revision 42

  • Revision 42 to the ODAM was approved/released on October 28, 2020.
  • Page 7: name change from "river" to "Cedar River".
  • Page 8: document irrigation systems have not been identified downstream from DAEC. Name change from "river" to Cedar River".
  • Page 9: ALARA achievement process for liquid releases.
  • Page 12: remove strawberry and vegetable consumption statement.
  • Page 13: name change from "river" to "Cedar River".
  • Page 14: remove irrigated vegetable pathway comments.
  • Page 15-16: update groundwater pathway description.
  • Page 58: include new vegetation sample location at D-59
  • Page 74: change to OSR 7.1.1.2 frequency from "24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />" to "prior to release".

Change to OSR 7.1.1.7 from "prior to release" to "92 Days". Change to OSR 7.1.1.8 from "prior to release" to "18 months".

  • Page 129: update comments to section 8.1.1.e.
  • Page 134: update comments to section 8.2.2.12.

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DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

SUMMARY

OF CHANGES TO THE DE-FUELED OFFSITE DOSE ASSESSMENT MANUAL {DODAM)

ODAM Revision 42 7 DODAM Revision 0

  • Revision 0 to the DODAM was approved/released on April 14, 2021.
  • Page 2: reference to section 3.3 removed.
  • Page 5: description of cessation of operations.
  • Page 7: update to section 2.1 for discharging liquid radiation waste.
  • Page 18: remove section 3.3.
  • Page 22: correction to time increment "t (yr)" to "t (hr)".
  • Pages 24-26, 28-29, 34-36, 46, 48, 51, 63-64, and 68: grammatical spacing errors.
  • Page 34: edit food pathway paragraph. Add "or, alternately" verbiage.
  • Page 39: update figure 3.1 gaseous radioactive waste flow diagram.
  • Page 40: update dose map and noble gas beta air dose distance.
  • Page 53: update to table 5.1. Discontinue air samplers at D-3, D-6, D-7, and D-
11. Discontinue D-15a soil sampling and D-16a soil and precipitation sampling.
  • Page 54: update to table 5.1. Grammatical error D-31. Discontinue air sampling at D-40.
  • Page 55: update table 5.1. Discontinue D-50 and D-63. Rename D-53, D-54, D-57, and D-58 as drinking water sources.
  • Page 56: update table 5.1. Rename D-72 as drinking water source. Discontinue D-76, D-77, and D-81 precipitation sampling.
  • Page 57: update table 5.1. Discontinue D-96, D-99, D-107a, D-108, D-109, D-110, and D-111.
  • Page 58: update table 5.1. Discontinue D-112, D-113, D-114, D-115, D-116, D-118, D-127 precipitation, D-128 precipitation, D-130, D-133, and 0135.

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DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

  • Page 59: update table 5.1. Discontinue D-136, D-137, D-138, D-166, D-168, D-172.
  • Page 60: edit "Functionality" and add the term "DODAM" to ACTIONS definition.
  • Page 61: update definition of "Functional-Functionality".
  • Page 62: edit to purpose section to clarify Defueled Offsite Dose Assessment Manual (DODAM) acronym.
  • Page 63: edit to description section to remove "inoperable" and replace with "non-functional". Remove "MODE" and paragraph and replace.
  • Page 65: remove "MODES" from OLCO 6.0.3.0.1 and OLCO 6.0.3.0.4. update OLCO 6.0.3.0.5 to include "non-functional" and "FUNCTIONALITY" terms.
  • Page 66: include "non-functional" term and grammatical spacing edit. Remove "MODE" from OSR 7.0.3.0.4.
  • Page 67: update table 6.1-1 section A to include terms "non-functional" and "FUNCTIONAL"
  • Page 68: update note section to include terms "non-functional" and "FUNCTIONAL"
  • Page 69: update table 6.1-1/7.1-1 to include "Functional" and update to table notation "c".
  • Page 73: update table 7 .1-2 grammatical spacing errors with table notations.
  • Page 75: update table notations for grammatical spacing errors.
  • Page 76: OCLO 6.1.3 paragraph grammatical spacing error.
  • Page 78: include in section A.1 "non-functional" term instead of "inoperable".
  • Page 80: section A.4 grammatical spacing error.
  • Page 81: section OSR 7.1.5.1 grammatical spacing error.
  • Page 82: OCLO 6.2.1.1 include "FUNCTIONAL" term and in section A. include "non-functional" term and section A.2 include "FUNCTIONAL" term.
  • Page 83: section G and G.1 include "functional" term.

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DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

  • Page 84: in NOTE section include "FUNCTIONAL" and "non-functional" terms.
  • Page 85: under the table 6.2-1 title include "Functional" term in minim channels.
  • Page 86: table notation for (b) include "FUNCTIONAL" and "non-functional" terms and grammatical spacing errors.
  • Page 87: remove sections 0 6.2.1.2 for off-gas system, table 6.2-2 and grammatical spacing error in section OCLO 6.2.2 subsection a.
  • Page 88: remove reference in Frequency for post-treat rad. Monitor under OSR 7.2.2.2. and OSR 7.2.2.3. Remove sections OSR 7.2.2.5 and OSR 7.2.2.7.
  • Page 89: remove table 7.2-2 surveillance requirements OSR 7.2.2.5 and OSR 7.2.2.7. Include section "A" as "Deleted". Grammatical spacing error in table notation (d).
  • Page 90: table 7.2-2 table notation remove analysis time requirements for 50%

increase in releases for post-treat noble gas monitor.

  • Page 94: grammatical spacing error in 30-day frequency.
  • Page 95: remove section 0 6.2.5 and 0 6.2.6 and include "timely" in B.1 paragraph.
  • Page 100: update for REMP minimum number of sampling stations in table 6.3-1.

Remove milk sampling.

  • Page 101: update table 6.3-2 minimum number of groundwater sampling stations. Remove soil and precipitation sampling.
  • Page 105: update radioactive liquid effluent instrumentation to include the "FUNCTIONAL" and "non-functional" terms.
  • Page 106: grammatical spacing error in 5th paragraph.
  • Page 107: under the Liquid Waste Treatment paragraph include "followed" term.
  • Page 108: grammatical spacing errors.
  • Page 109: grammatical spacing errors.
  • Page 110: include the "FUNCTIONALITY", "FUNCTIONAL", and "non-functional" terms in paragraphs 1-3. Remove paragraph referencing two air injectors and off-gas post-treatment monitors.

Page 34

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT

  • Page 111: remove reference to standby gas treatment system and section 6.2.5 and 7.2.5 for gaseous radwaste treatment. Include line space after paragraph 4 ending with "waste streams."
  • Page 113: grammatical spacing error section 8.1.1.g.2
  • Page 115: grammatical spacing error 8.2 Reporting Requirements.
  • Page 119: remove 8.2.3.2 special reports referencing off-gas system. Add section "2. Deleted".
  • Page 120: include "document" term in 8.3.a. Include "Decommissioning" in 8.3.b.

Include "changed and" in 8.3.c.

  • In Appendix A, remove dose transfer factors for radionuclides in effluent air.

Pathways for cow milk for adult, teenager, child, and infant and goat milk for adult, teenager, child, and infant.

o Remove pages 125-126, 132-133, 139-140, and 146-147.

  • In Appendix C, remove pathway references to irrigated fresh leafy vegetables, irrigated stored vegetables, fruit, and grain, freshwater invertebrates, irrigated grass cow milk-cow meat, and irrigated stored forage cow milk-cow meat.

o Remove pages 161-176, 189-204, 217-232, and 245-260 Revision: 34 35 36 37 38 39 40 41 42 DODAM-0 Date: 12/18/15 3/1/16 9/2/16 2/9/17 1/2/18 4/5/18 3/11/19 4/6/20 10/28/20 4/14/21 Page 35

DUANE ARNOLD ENERGY CENTER 2020 ANNUAL RADIOACTIVE MATERIAL RELEASE REPORT ATTACHMENT 1: SEWAGE EFFLUENT-DAEC LABORATORY There were 53 sewage effluent samples collected in 2020. There were no plant by-products identified in the samples. The maximum value for the lower limit of detection (LLD) for environmental sample analysis are noted below and in the ODAM-DODAM, Table 6.3-3.

SEWAGE SAMPLES Maximum Value for Activity the Lower Limit of Detection (pCi/L)

Gross Beta 4 2,000<*>

Tritium 3,000(b)

Mn-54 15 Fe-59 30 Co-58 15 Co-60 15 Zn-65 30 Zr-95 30 Nb-95 15 1(*)

1-131 15(~)

Cs-134 15 Cs-137 18 Ba-140 60 La-140 15 Other (c) 30

<*> Drinking water

!bl Non-drinking water (c) Non-routine, plant by-products Page 36

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