ML112980304

Letter to Mary Stamos Re Three Mile Island

ML112980304
Person / Time
Site:	Crane
Issue date:	10/19/2011
From:	Eugene Dipaolo Division Reactor Projects I
To:	Stamos M - No Known Affiliation
dipaolo, em
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Download: ML112980304 (54)

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Dear Ms. Stamos:

I am responding to questions you raised about the Three Mile lsland (TMl) nuclear power plant in a collection of letters mailed to the NRC on August 30, 201 1. You had questions about the health effects of the Three Mile lsland accident. In particular, you were concerned about a metallic taste you experienced at the time of the accident. You also expressed concern about the quantity of radioictive materials released by the operating unit, Three Mile lsland Unit 1. As stated in a letter sent to you in July 2004, the NRC has no definitive technical explanation regarding the metallic taste you expeiienced during the accident. Extensive studies of the raliotogilal consequences of the TMI-2 accident calculated that the maximum dose to a person located at the site boundary would have been less than 100 millirem. Such a dose is considerably less than the'5 rer (5000 millirem) you say causes a metallic taste. Attached for your review is a document tiiled "dackgrounder: ihree Mile lsland Accident" summarizing the Three Mile lsland Accident and its potential health etfects. This document also lists additional sources of information which may prove useful to you and directions for obtaining them' The radioactive effluents released from TMI-1 during 2010 resulted in doses that were a small fraction of NRC regulatory limits. This is discussed in the 2010 Annual Radioactive Effluent UNITED STATES NUCLEAR REGU LATORY COMMISSION REGION I 475 ALLENDALE ROAD KING OF PRUSSIA. PENNSYLVANIA 19406-1415 0ctober 19, 2OII Ms. Mary Stamos Release Report for TMl. Excerpts from the report are attached as well. The full report can be found on the NRC website at httP:/ info.html. Thank you for your continued interest in nuclear safety. lf you have any further questions, please contact me at (610) 337-5046. Sincerely, 4^--nL /U//u Eugene M. DiPaolo, Acting Chief Division of Reactor Projects Branch 6 US NRC Backgrounder on the Three Mile lsland Accident Excerpts from three Mile lsland Combined 2010 Radioactive Effluent Release Report 1) 2)

Enclosures:

Ms. Mary Stamos

Dear Ms. Stamos:

I am responding to questions you raised about the Three Mile lsland (TMl) nuclear power plant in a collection of letters mailed to the NRC on August 30, 201 1. You had questions about the health effects of the Three Mile lsland accident. In particular, you were concerned about a metallic taste you experienced at the time of the accident. You also expressed concern about the quantity of radioactive materials released by the operating unit, Three Mile lsland Unit 1. As stated in a letter sent to you in July 2004, the NRC has no definitive technical explanation regarding the metallic taste you experienced during the accident. Extensive studies of the radiological consequences of the TMI-2 accident calculated that the maximum dose to a person located at the site boundary would have been less than 100 millirem. Such a dose is considerably less than the 5 rem (5000 millirem) you say causes a metallic taste. Attached for your review is a document titled "Backgrounder: Three Mile lsland Accident" summarizing the Three Mile lsland Accident and its potential health effects. This document also lists additional sources of information which may prove useful to you and directions for obtaining them. The radioactive effluents released from TMI-1 during 2010 resulted in doses that were a small fraction of NRC regulatory limits. This is discussed in the 2010 Annual Radioactive Effluent Release Report for TMl. Excerpts from the report are attached as well. The full report can be found on the NRC website at http:i/www.nrc.qov/reactors/operatinq/ops-experience/tritium/plant-info.html. Thank you for your continued interest in nuclear safety. lf you have any further questions, please contact me at (610) 337-5046. Sincerely, A//U.fu/1,-'= Eugene M. DiPaolo, Acting Chief Division of Reactor Projects Branch 6 ./ suNst Review complete: ( Ftn"uiewer's Initiats) DOCUMENT NAME: G:\\DRP\\BRANCH6\\+++Three Mile lsland\\Letter to Mary Stamos TMl.docx Afier declaring this document "An Official Agency Record" it will be released to the Public. To receive a copy of this document, indicate in the box: 'C" = Copy without attachmenVenclosure 'E" = Copy with attachmenUenclosure "N" = No copy

Enc losur e 'U,S.NRC BACKGROUNDER Llm D\\t^rl\\ \\t:cthn rux;t't. ilorl cos\\ll$tl{)$ Pblsrrang l)otth' flnrl tht Ewircnwatl Office of Public Atfairs Phone: 301 -41 5-8200 Email: Three Mile Island Accident The accident at the Three Mile Island unit 2 (TMI-2) nuclear power plant near Middletown, Pa', on March Zg, lgTg,was the most serious in U.S, commercial nuciear power plant operating history, evcn though it led to 'o deaths or injuries to plant workers or members of the nearby cotnmunity. But it brought about sweeping changes involving emergency response planning, reactor operator training, human factors "ngin".iing, raiiation protection, and many other areas.of nuclear power plant operations' It also caused the u.S. Nuclear Reguiatory commission io tighten and heighten its regulatory oversight' Resultant changes in the nucl# po*Lr industry and at the NRC had the effect of enhancing safety' The sequence of certain events - equipment malfunctions, design-related problems and worker errors

• led to ;partial meltdown of the rMr-z reactor core but only very small off-site releases of radioactivity, Summary of Events The accident began about 4:00 a.m. on March 28,l97g,when the plant experienced a failure in the secondary, non-nuclear section of the plant, The main feedwater pumps s-topped running, causgd by-either a mechanical or electrical failure, which prevented the steam generators from removing heat' First the turbine, then the reactor automatically shut down. Immediately, the pressure in the primary systcm (thc nucleaiportion of the plant) began to increase. In order to prevent that pressure from becoming excessive, the piloioperated relief valve (i valve located at the top of the pressurizer) opened"-The valve should have closed when the pressure decreased by a certain amount, but it did not. Signals available to the operator failed to show that the valve was still open. As a result, cooling water poured out of the stuck-open valve and caused the core ofthe reactor to overheat.

As coolant flowed from the core through the pressurizer, the instruments available to reactor operators fiovided confusing information. There *ur nb insffument that showed the level of coolant in the core. Instead, the operators judged the level of water in the core by the level in the pressuri zet, and since it was high, ttrey assumed that ttie core was properly covered with coolant, In addition, there was no clear signal that the pilot-operated relief valve *ui open.'As a result, as alarms rang and warning lights flashed,.the operators did not rca]izethat the plant was experiencing a loss-of-coolant accident' They took a series of actions that made conditions *orr. by simply reducing the flow of coolant through the core' Because adequate cooling was not available, the nuclear fuel_overheated to the point at which the zirconium cladding (the i"ong metal tubes which hold the nuclear fuel pellets) ruptured and the fuel pellets began to melt. It was later fJund that about one-half of tho corc melted during the early stages of the accident. Although the TMI-2 plant suffered a severe core meltdown, the most dangerous kind of nuclear fo*.,. accident, i] did not produce the worst-case consequences that reactor experts had long feared' In a worst*case accident, the melting of nuclear fuel would lead to a breach of the walls of the containment building and release massive qiantities of radiation to the environment. But this did not occur as a result of the three Mile Island accident.

The accident caught fecleral and state authorities off-guard. They were concetned about the small releases of radioactiv. gur., that were measured off-site by the late morning of March 28 and-even more concerned about the potentiat threat that thc rcactor posed to the surrounding population. They did not know that the core had melted, but they imrnediately took steps to try to gain control of the reactor and ensure adequate cooling to the core. Tlie NRC's regional office in King of Prussia, Pa,, was notified at7:45 a.m. on March ZS. ny t:OO, NRC Headquarters in Washington, D.C., was alerted and the NRC Operations Center in Bethesda, Md., was activated. The regionaioffice promptly dispatched the first team of inspectors to the site and other agcncies, such as the Department of Energy and the Environmental Protection Agency, also mobilized their response teams. I{elicopters hired by TMI's owner, General Public Utilities Nuclear, and the Department of bnergy were sampling radioactivity in the atmosphere above the plant by midday. A team from the Brookhaien National Laboratory was also sent to assist in radiation monitoring. At 9:i5 a.m., thc White House was notified and at 1 1:00 a.m., all non-essential personnel were ordered off the plant's premises. By the evening of March 28, the core appeat'ed to be adequately cooled and the reactor appeared to be stable. But new concerns arose by the morning of Friday, March 30. A significant release of radiation from the plant's auxiliary building, peiformed to reiievc prcssure on the primary system and avoid curtailing the flow of coolalt to the core, caused a greatdeal of c-onfusion and consternation. In an atmosphere of growing uncertainty about the condition of the plant, the govefiior of Pa', Richard L. Thornburgh, consulted with the NRC about evacuating the population n.ut the plant. Eventually, he and NRC Chairman Joseph Hendrie agreed that it would Ue prua"nt for those members of society most vulnerable to radiation to evacuate the area. Thornburgh announced that he was advising pregnant women and pre-school-age children within a 5-mile radius of the plant to leave the area' Within a short time, the presence of a large hydrogen bubble in the dome of the pressure vcssel, the container that holds the ieactor core, stined new worries. The concel'n was that the hydrogen bubble might burn or even explode and rupture the pressure vessel. In that event, the core would fall into the containment building and peihaps.uur. i breach of containment. The hydrogen bubble was a source of intense scrutiny and gre-at anxiety, both among government authorities and the population, throughouJ the day on Saturday, March 31. The crisis ended wiJn experts determined on Sunday, April 1, that the bubble could not burn or explode because of the absence of oiygen in the pressure vessel. Further, by that time, the utility had succeeded in greatly reducing the size of the bubble' Health Effects Detailed studies of the radiological consequences of the accident have been conducted by the NRC, the Environmental Protection Agelncy, the Department of Health, Education and Welfare (now Health and Human Services), the Deparlment of Energy, and the State of Pa.. Several independent studies have also been conducted. Estimates are that the uu*ug" dose to about 2 million people in the area was only about 1 millirem. To put this into context, exposure f,otn u chest x-ray is about 6 millirem. Compared to the natural radioactive background dose of about I 00- 125 millirem per year for the area, the collective dose to the community from-the accident was very small. The maximum dose to a person at the site boundary would have been less than 100 millirem. In the months following the accident, although questions were raised about possible adverse effects from radiation on human, animal, and plant life in the TMI area, none could be directly conelated to the accident. Thousands of environmental samples of air, water, milk, vegetation, soil, and foodstuffs were collected by various groups monitoring the area. Very low levels of radionuclides could be attributed to

releases from the accident. However, comprehensive investigations and asssssments by several well-respected organizations have concluded that in spite of serious damage to the reactor, most of the radiation was contained and that the actual release had negligible effects on the physical health of individuals or the environment. Impact of the Accident The accident was caused by a combination of personnel error, design deficiencies, and component failures', There is no doubt that the accident at Three Mlle Island permanently changed both the nuclear industry and the NRC. public fear and distrust increased, NRC's regulations and oversight became broader and more robust, and management of the plants was scrutinized more carefully, The problems identified from careful analysis of the evlnts during those days have led to permanent and sweeping changes in how NRC reguiates its licensees - wh[h, in turn, has reduced the risk to public health and safety. Here are some of the major changes which have occurred since the accident: , UpFading and strengthening of plant design and equipment requirements._This includes fire piJectioti, piptng,yit*rnr, a:uxiliary feedwater systgm;, containment building isolation, reliability of individual coriponents (pressurarelief valves and electrical circuit breakers), and the ability of a a plants to shut dowr automaticallY; identiffing human perfotmance as a critical part of plant s.afety, revamping operator training and staffing reluirements, followed by improved instrumentation and controls for operating the plant, and establishment of fitness-for-duty progtatos for plant workers to guard against alcohol or drug abuse; Improved instruction to avoid thc confusing signals that plagued operations during the accident; Enhancement of emergency preparedness to include immediate NRC notification requirements for plant events and an Ni.C op"rations center that is staffed 24 hours a day' Drills and response plans

• . no* tested by licensees several times a year, and slate and local agencics participate in drills with the Federal Emergency Management Agency and NRC; Establishment of a prolru-to intelrate NRC observations, findings, and conclusions about licensee performance and management effectiveness into a periodic, public report; hegular analysis of plait performance by senior NRC managers who identiff those plants needing additional regulatory attention ;

Expansion gFNRC'r resident inspector program - first authorized in 1977

• whereby at least two inspectors live nearby and work exclusively at each plant in the U.S. to provide daily surveillance of licensee adherence to NRC regulations; Expansion of performance-or[nted as well as safety-oriented inspections, and the use of risk assessment toidentify vulnerabilities of any plant to sevele accidents; Strengthening and reorganization of enforcement as a separate office within the NRC; The eitablish-ment of tlie Institute of Nuclear Power Operations (INPO), the industry's o\\rm

,,policing,, group, and formation of what is now the Nuclear Energy Institute to provide a unified lnoustry-approurh to generic nuclear regulatory issues, and interaction with NRC and other govemment agencies; The installing oruooitlonal equipment by licensees to mitigate accident conditions, and monitor radtation levels and Plant status; Employment of major initiatives by licensees in early identification of important safety-related protl.*r, and in collecting and assessing relevant data so lessons of experience can be shared and quickly acted upon; and o a

. Expansion of NRC's international activities to share enhanced knowledge of nuclear safety with other countries in a number of important technical areas. Current Status Today, the TMI-2 reactor is permanently shut down and defueled, with the reactor coolant system drained, the radioactive water decontaminated and evaporated, radioactive waste shipped off-site to an appropriate disposal site, reactor fuel and core debris shipped off-sitc to a Department of F.nergy facility, and the remainder of the site being monitored. In 2001, FirstEnergy acquired TMI-2 from GPU. FirstEnergy has contracted the monitoring of TMI-2 to Exelon, the curent owner and operator of TMI-1. The companies plal to keep the TMI-2 facility in long-term, monitored storage until the operating license for the TMI-1 plant expires, at which tirne both plants will be decommissioned. Below is a chronology of highlights of the TMI-2 cleanup from 1980 through 1993. Date July 1980 July 1980 Nov. 1980 July 1984 Oct, 1985 July 1986 Aug. 1988 Jan. 1990 July 1990 Jan,199l April 1991 Feb.1992 Aug. 1993 Sept. 1993 Event Approximately 43,000 curies of krypton were vented from the reactor building. The first manned entry into the reactor building took place. An Advisory Panel for the Decontamination of TMI-2, composed of citizens, scientists, and State and local officials, held its first meeting in Harrisburg, PA. The reactor vessel head (top) was removed. Defueling began. The off-site shipment of reactor core debris began, GpU submitted a request for a proposal to amend the TMI-2 license to a "possession-only" license and to allow the facility to enter long-term monitoring storage. Defueling was completed. GpU submitted its funding plan for placing $229 million in escrow for radiological decommissioning of the plant. The evaporation of accident-generated water began. NRC published a notice of opportunity for a hearing on GPU's request for a liccnse amcndment NRC issued a safety evaluation report and granted the licensc amendment. The processing of 2.23 million gallons accident-generated water was completed. NRC issued a possession-only license.

Sept. 1993 The Advisory Panel for Decontamination of TMI-2 held its last meeting. Dec. 1993 Post-Defueling Monitoring Storage began' Additional Information Further information on the TMI-2 accident can be obtained from sources listed below. The documents can be ordered for a fee from the NRC's Public Document Room at30l-415'4737 or 1-800-397-4209; e-matl p!i,,6gu-{q,g{)-y, The pDR is located at 11555 Rockville Pike, Rockville, Maryland; however the mailing ,ddrr*-

• U.S, Nuclear Regulatory Commission, Public Document Room, Washington, D.C. 20555' A glossary is also Provided below.

Additional sources for Information on Three Mile Island NRC Annual Report - l979,NUREG-0690 ,,population Dose and tteaittr Impact of the Accident at the Three Mile Island Nuclear Station," NUREG-0558 .,Environmental Assessment of Radiological Effluents from Data Gathering and Maintenance operation on Three Mile Island lJnit2," NUREG-0681 .,Report of The president's Commission on The Aocident at Three Mile Island," October, 1979 ,.Investigation into the March 28,lgTg Three Mile Island Accident by the Office of Inspection and Enforcement," NUREG-0600 ,Three Mile Island; A Report to the Commissioners and to the Public," by Mitchell Rogovin and George T. Frampton, NUREG/CR-1250, Vols' I-II, 1980 ,,Lessons learned From the Three Mile Island - Unit 2 Advisory Paneln" NUREG/CR-6252 ,,The Status of Recommendations of the President's Commission on the Accident at Three Mile Island," (A ten-Year review), NUREG-1355 ,,NRC Views and Analysis of the Recommendations of the President's Commission on the AL:cident at Three Mile Island," NUREG-0632 .,Environmental Impact Statement related to decontamination and disposal of radioactive wastes resulting from March Zg, IgTg accident Three Mile Island Nuclear Station, IJnit2," NUREG-0683 ,,Answers to euestions About updated Estimates of occupational Radiation Doses at Three Mile Island, Unit 2." NUREG-1060 ,,Answers to Frequently Asked Questions About Cleanup Activities at Three Mile Island, Unit 2," NUREG-0732 ,,Status of Safety Issues at Licensed Power Plants" (TMI Action Plan Reqmts'), NUREG-1435

Walker, J. Samuel, Three Mile Island: A Nuclear Crisis in Historical Perspective, Berkeley: University of California Press, 2004. Glossary Auxiliary feedwater - (see emergency feedwater) Background radiation - The radiation in the natural environment, including cosmic rays and radiation from ihe naturally radioactive elements, both outside and inside the bodies of humans and animals. The usually quoted average individual exposurc from background radiation is 300 millirem per year. Cladding - The thin-ialled rnetal tube that forms the outer jacket of a nuclear fuel rod. It prevents the corrosion of the fuet by the coolant and the release of fission products in the coolants. Aluminum, stainless steel and zirconium atloys are common cladding materials. Emergency feedwater system - Backup feedwiter supply used during nuclear plant startup and shutdown; also known as auxiliary feedwater. Fuel rod - A long, slender tube that holds fuel (fissionable material) for nuclear reactor use. Fuel rods are assembled into bundles called fuel elements or fuel assemblies, which are loaded individually into the feactor core. Containment - The gas-tight shell or other enclosure around a reactor to confine fission products that otherwise might be released to the aknosphere in the event of an accident. Coolant - A substance circulated through a nuclear reactor to remove or transfer heat. The most commonly used coolant in the U.S. is water. Other coolants include air, carbon dioxide, and helium. Core - The central portion of a nuclear reactor containing the fuel elentents, and control rods, Decay heat - The lreat produced by the dccay of radioactive fission products after the reactor has been shut down. Decontamination - The reduction or removal of contaminating radioactivc material from a structure, area, object, or person, Decontamination may be accomplished by (1) treating the surface to rernove or decrease the contamination; (2) letting the mateiial stand so that the radioactivity is decrcased by natural decay; and (3) covering the contamination to shield the radiation emitted' Feedwater - Watcr supplied to the steam generator that removes heat from the fuel rods by boiling and becoming steam. The steam then becomes the driving force for the turbine generator' Nuclear Reactor - A device in which nuclear fission may be sustained and controlled in a self-supporting nuclear reaction. There are several varieties, but all incorporate certain features, such as fissionable material or fuel, a moderating material (to control the reaction), a reflector to conserve escaping neuffons, provisions for removal of heat, measuring and controlling instrumcnts, and protective devices' b..rrur. Vessel - A strong-walled container housing the core of most types of power reactors. pressurizer - A tank or vessel that controls the pressure in a certain type of nucl eat teactor ' primary System - The cooling system used to..mou. energy from the reactor core and transfer that energy eithlr directly or indirectly to the steam turbine. Radiation - par-ticles (alpha, betan neutrons) or photons (gamma) emitted from the nucleus of an unstable atom as a result ofradioactive decay. Reactor Coolant System - (see primary system) Secondary System - The steam generatoriubes, steam turbine, condenser and associatcd pipes, pumps, a1d heaters uscd to convert the heat Jn"rgy ofthe reactor cootant system into mechanical energy for electrical generation. Steam Generator - The heat exchanger used in some reactor designs to transfer heat from the primary (reactor coolant) system to the secondary (steam) system. This design permits heat exchange with little or no contamination of the secondary system equipment'

Turbine - A rotary engine made with a series of curved vanes on a rotating shaft' Usually tumed by water or steam. Turbines are*considcred to be the most economical means to turn large electrical generators, Rnoii* "mo Pntp August 2009 .::.,,r. i;.tliriiiitil&i,,ldii:rr',:i.liir:.,, TMI-! \\ ' nHACTOfi BUILDINO ",'\\,*, I cooLlNG rowER P'H4vrr'dd utoo} gr lll.llt \\i11,': i rr,l*, vat{d ,tl!c ,ill virt' ] \\ \\, /t'n'unr$ I "o'r - lffi d\\1 -"' *'*'-***'-*""t rriisrs.:urqr j

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2010 Annual Radioactive Eftluent Release ReportlorTMl Attachment I - Page 2 ol 15 TABLE 1A EFFLUENT AND WASTE DISPOSAL ANNUAL REPORT 2O1O GASEOUS EFFLUENTS - SUMMATION OF ALL RELEASES 'ODCM Limits - Usted on Dose summary Table.

• C-14 production was estimated using EPRI Technical Report 1021100 Methodology.

H ts a Io N] TMFl ffiting ol TMIODCM Lower Lirnil of Detection {LLD).

2010 Annual Radioactive Effluent Release Report for TMI - Page 5 of 15 TABLE 2A EFFLUENT ANDWASTE DISPOSAL ANNUAL BEPORT 2O1O LIOUID EFFLUENTS - SUMMATION OF ALL RELEASES TMhl UNIT QUARTERI I OUARTER2 QUARTER3 QUARTER 4 ESTTOTAL ERROR o/" A. FISSION AND ACTIVATIS}I PRODUGTS 1-Total Release (Not incl. Tritium. qases, alpha) ci 1.18E-05 4.34E-Os 1.99E-05 8.41 E-05 25"/"

2. Avo diluted concentration clurino Derlod uCi/rnl 1.71E-'t2 7.08E-12 2.77E-'12 1.28E-11

3. Percent of applicable limit

, -,':.i::1,;.:.X:;l ;i: :.i: '_.'i i:i.. i.:+,r.'. _.:.:: j:i..;::il:.r:. ir...:'1- : - +; 1..:.it;,.:s+:,*.; iti:':iti,a:i,:;jj-fi.rj::ti"tlii.X.{-l-e.iii;ilra 5 F :l:iii. t r+,:.'i; j :i'. :#?..i'il-.:::-.fi ir B. TRITIUM 1-Total Release Ci 1.42E+O'l 6E+Ol 4.40E+OI 5.39E+O1 25"/" 2-Avq diluted concentration clurinq periocl uoi/ml 2.07E{6 2.71E{'6 6.13E-06 8.23E-05

3. Percent of applieable limit o/o l

l ll:i-iifi.Si*5"rdtrIsf,ssfl*"{ir.Jli.trffi#ii$ffi*ffi i}i{i"i&ffi:g a{-d];{.*il: i5t:$.F{i,=?: C. DISSOLVED AND ENTRAINED GASES iiF-i;:ii,:?-1i';;5:..,.:i'-T 1-Total Belease ci <LLD <LLD 1.07E44 1.20E-04 ,o

2. Avq diluted concentration durino periocl uCi/ml N/A N/A 1.49E-1 1 1.83E-11 3

Pcrcent af annlinahlc limit o/ol'l D. GROSS ALPHA RADIOACTIVITY 1-Toial Release ci <LLD <LLD <LLD 25V" _ tSil{q-K4iki:Sts..iFri.-lqigfu:li$ li+i:i.ijh:....j.i,rS,,:r.i::::i.-.:.:ir,' lier:-t;ci:j+ir'.+'.ir:r31i{'iill-F-.':r',ir:'.i{r.::.j:t";'i.}i}jif;..ii:':; ei ';ii {.i'irii lii}i'tif{liild.n':::r,ir*lf ;-:i: iG_S::jj:if.;.i E. VOLUME OFWASTE RELEASE (PRTORTO DILUTIONT LITERS 1.14E{OB 1.12E+08 1.16E+OB 1.20E+08 fiV" F. VOLUME OF DILUTION WATER USED LITERS 6.88E+Og 5.13E+09 7.17E+09 6.55E+09 10% Note: Table 3 contains a listing of TMI ODCM Lower Limit of Detection (LLD). "ODCM Limits - Listed on Dose summary Table

2010 Annual Radioactive Effluent Release Report for TMI AftachmentT-Page1 ol4 Assessment of Radiation Doses Due to Radioactive Liquid and Gaseous Effluents Released from TMI During 2010 TMr-1 The attached table presents the maximum hypothetical doses to an individual and the general popri.iion resulting irom 2010 TMl.1 reteases of gaseous and liquid etfluents. Provided below is a brief explanation of the table. A. Liqr.{id(lnSividual) Calculations were performed on the four age groups and seven organs recommended in Aegufatory Guide i.rOg. The pathways considered for TMI-1 were the consumption of dririking water and fish and standing on tlre shoreline influenced by TMI'1 effluents, The tuttrr tfro pathways are considered io be the primary recreational activities associated with tne Susqu'enanna River in the vicinity of TMl. The "critical receptor" or Receptor 1 was that individualwho 1) consumed Susquehanna River water from the nearest downstream drinking

• itur rrpplier (Wrightsville Water Supply), 2) consumed fish residing !n the vicinity of the TMI-1 liquid dischalge and 3) occupied an area of shoreline influenced by the TMI-1 liquid discharge.

For 2010 the calculated maximum whole body (or total body) dose from TMI'1 liquid effluents was 1.43E-2 mrem to an adult (line 1), The maximum organ dose was 1.50E-2 mrem to the liver of an adult (line 2). B. @ryqdryueu There were six major pathways considered in the dose calculations for TMI-1 gaseous effluents. These were: '(1) pluine exposure (2) inhalation, consumption of; (3) cow milk' (4) vegeianfes and fruits, (bi heat, and (6) standing on contaminated ground. Realtime miteorotogy was used in all dose calculations for gaseous effluents' Lines O and 4 present the maximum plume exposure at or beyond the site.boundary. The notation of 'hir.dose" is interpreted to mean that these doses are not to an individual, but is considerecl to be the maximum doses that would have occurred at or beyond lhe site oounOary. The table presents the distance in meters to the location in the affected sector t.orpuri point) wherd the theoretical maximum plume exposures occuned' The calculated maximum 'plurne exposures were 1.17E-4 mrad and 3.72E-4 mrad for gamma and beta, resPectivelY. The maximum organ dose due to the release of iodines, particulates and.tritium from TMI-1 in 2010 was 1,OgE-1 mrem to the bone of a child residing 2150 meters from the site in lhe NNE sector (line S). This dose again reflects the maximum exposed organ for the appropriate age group, For 2010, TMI-1 liquid and gaseous effluents resulted in maximum hypothetical doses that were a smallfraction of the quarterly and yearly oDcM dose limits'

2010 Annual Radioactive Effluent Release Report for TMI AttachmentT-Page2of4 TMFl

SUMMARY

OF MA)OMUM INDIVIDUAL DOSES FOR TMF1 FROM Januarv 1. 2010 through December 31' 2010 Effluent Applicable Organ Estimaled Dose (mrem) Age Group Location Dist Dir (m) (to) % of ODCM Dose Limit ODCM Dose Limit (mrem) Quarter Annual Quafter Annual (1) Liq uid {2) Liquid Totat Body Liver 1.43E-2 1-50E-2 Adult Aduft Receptor 1 Beceptor 1 9.53E-1 3.00E-1 4.77E-2 1.50E-1 1.5 3 3 10 (3) Noble Gas (4) Noble Gas Air Dose (gamma-mrad) Air Dose (beta-mrad) 1.17E-4 3.72E-4 610 SSE 3000 SSE s.85E-2 3.72E-3 1.17E-3 1.86E-3 5 10 10 20 (5) lodine, Tritium & Particulates Bone 1.53E-1 chird 2150 NNE 2.MEO 1.02E0 7.5 15

2010 Annual Fladioactive Effluent Release Fleportfor TMI AttachmentT*Page3of4 lMr-2 The attached table presents the maximum hypothetical doses to an individual and the general population resulting from 2010 TMI-2 releases of gaseous and liquid effluents, Provided below is a briel explanation of the table. A. Liquid (lndividual) Calculations were performed on the four age groups and seven organs recommended in Regulatory Guide 1.109. The pathways considered for TMI-2 were the consumption of drinking water and fish and standing on the shoreline influenced by TMI-2 etfluents. The latter two pathways are considored to be the primary recreational activitjes associated with the Susquehanna River in the vicinity of TMl. The "critical receptor" or Receptor 1 was that individuiil who 1) consumed Susquehanna River water from the nearest downstream drinking water supplier (Wrightsville Water Supply), 2) consumed fish residing in the vicinity of the TMI-2 liquid discharge and 3) occupied an area of shoreline influenced by the TMI-2 liquid discharge. For 2010 the calculated maximum whole body (or total body) dose from TMI-2 liquid effluents was 3.04E-4 mrem to an adult (line 1). The maximum organ dose wae 4.758-4 mrem to the liver of a teen (line 2). B. Gaseous(lndividuql) There were six major pathways considered in the dose calculations for TMI-2 gaseous elfluents, These were: (1) plume exposure (2) inhalation, consumption ol; (3) cow milk, (4) vegetables and fruits, (5) meat, and (6) standing on conlaminated $round, Real-time meteorology was used in all dose calculations for gaseous etfluents. Since there were no noble gases released from TMI-2 during 2010, the gamma and beta air doses (lines 3 and 4, respectively)were zelo. The maximum organ dose due to the release of particulates and tritium from TMI-2 in 2010 was 3.87E-5 mrem to the liver, total body, thyroid, kidney, lung, and Gl tract of a child residing 2000 meters from the site in the SE sector (line 5)' For 2010, TMI-2 liquid and gaseous effluents resulted in maximum hypothetical doses that were a smallfraction of the quarterly and yearly ODCM dose limits.

2010 Annual Radioactive Effluent Release Reportlor TMI AtlachmentT-Page4ol4 TI\\'ll-2

SUMMARY

OF MA)fiMUM TNDIVIDUAL DOSES FOR TMI-2 FROM Januarv 1.2010 through Decmber 31.2010 Eff luent Applicable Organ Estimated Dose {mrem) Age Group Location Dist Dir (m) (to) "/" of ODCM Dose Limit uuuM uose Limit(mrem) Quarter Annual Quarter Annual (1) Liquid (2) Liquid Total Body Liver 3.04E-4 4.75E-4 Ardult Teen Receptor 1 Receptor 1 2.O3E-2 9.50E-3 1.01E-2 4.75E-3 1.5 5 3 10 (3) Noble Gas (4) Noble Gas Air Dose {gamma-mrad) Air Dose (beta-mrad) u 0 0 0 0 0 5 10 10 2A (5) Tritium & Particulate Liver, Total Body, Thyroid, Kidney, Lung & GlTract 3.87E-5 chitd 2000 5E 5.16E-4 2.58E-4 7.5 15}}