ML20210P872

Post Decommissioning Activities Rept, for Aug 1997

ML20210P872
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	08/31/1997
From:	CONNECTICUT YANKEE ATOMIC POWER CO.
To:
Shared Package
ML20210P860	List: ML20210P856 ML20210P872
References
NUDOCS 9708270381
Download: ML20210P872 (16)

Text

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l Haddam Neck Plant l Post Shutdown Decommissioning Activities Report 3

J Aligust 1997 9708270381 970822 P, DR, ADOCK 05000213- I W PDR

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. ,. Table of Contents 1-

- I NT R O D U CT I O N . . .... .. . . . . .. . ..... .. .. . ... . . .. . .. . . . .. . . . . . . .. . .... ... .. . . ... . . . ..... .. .. . . . .. . .. . . ... .. . . .. .... . .. . . . .. . .. !

HACKGROUND................................................................................................................I DEsCRIPTlON OF PLANN ED DECOM MISSIONING ACTIVm ES..... .......... ................. ........ 2 -

Decemmh aonIng A caaaes and PIannine . .......... .............. .... . ........... . .... ......... .2 PIanning Actirities (Prior Io SubmittaI ofIhe PSDAR) .....................................................2 pia n t Dh man tIem en t ... .... .. ....... ... .... ......... .. ........ ...~.. .. ..... .. .. ................. ...... ......,.......... 2 M A JO R D ECO M M ISS I O N I NG A CTI VIT1 ES....... .......... ........ ........................ .. r3 Reaetar D'esselandInIernah.... ...... . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . . . ............................. 3 Stea m Gen era to rs . .. ................... ... .. .... . .......... ......... ...............-~................... .....~.. 1 Pres s u rl:er .. ............ ..- ........ ....... ..........-......... ............................................4 Reaetor CooIant System (RCS) and 0ther Large Rore Piping..... .

......................... 4 Cemtalnment.....-..................................................................- .-......................................A SpenifuelPool..-..............-........................-...........................................................5 OTIi E R D ECO M M ISS I ON I N G CON S l D E R ATIO NS ................................... .. .. ........ .. -5 Chemical Decontaminatlon of Primary Coolant Systems . . .........................................$

General Decommissioning Activities - Removal of Radiological Components & Structures ..............$

Decon Iamin ation h Ieth ods ... ... .... .... .. .............-....... ........................ ........... ........... ............ 6 Dh man tIemen t A feth ods .. ............ .......... .. ......... ....... ........... ....... ... ....... ................ ........ 6 SpecIaI or Unusuat ?rograms .......--....... ... ........ .................................................7 Removal of Low Level Radioactive Waste (LL H) and Compaction or incineration ........ ................ 7 SoIi RemedIatIon .... ................. . ... . .. ..... ............ ... .......................................... ..... 7 Procening and Dhvosal Site Loeattons .-........... ...... ....... .... .... -..............-. ....-.............7 Remo yaI of AIhed Wa:tes......... .. ........... ............. .... .............-...............................7 StoragelRemo yaI ofSpent Fuel and GTCC Wa ste. ... .... .................... ........ ...-.......................... 8 S I T E R ESTO R AT l O N ...- . ......... ... . .. .............. ................ ........._......................................8 SCII E DU LE FOR DECOM M ISSIONING ACTIVITI ES ........................................... 8 ESTIM ATE OF EXPECTED DECOMMISSIONING COSTS................................... 8

- E N V I RO N M E NTA L I M P A CTS .............................................................. ...... ................. 9 REFERENCES................................................................................................................11 I

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t LIST OF ACRONYMS CYAPCO Connecticut Yankee Atomic Power Company DECON Immediate Decontamination and Dismantlement Option DF Decontamination Factor DOE Department of Energy ENTOMil Encasement in Concrete with Future Dismantlement Option FGEIS Final Generic Environmental Impact Statement GTCC Greater Than Class C llEPA liigh Efficiency Particulat. Air [litterl llNP lladdam Neck Plant

1. PSI Low Pressure Safety Injection NitC Nuclear llegulatory Commission PSDAll Post Shutdown Decommissioning Activitica iteport itCS lleactor Coolant System 111111 Ilesidual llent itemoval System SAFSTOlt Delayed Decontamination and Dismantlemmt Option UFSAll Updated Final Safety Analytis lleport 10CFit61 Licensing itequirements for Land Disposal of Radioactive Waste 10CFit71 Packaging and Transportation of Itadioactive Material ii

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Haddam Neck Plant Post Shutdown Decornmissioning Activities Repatt INTitODUCTION Under the provisions of 10CFR50.82(a)(4)(i), Connecticut Yankee Atomic Power Company (CYAPCO) hereby submits this Post Shutdown Decommissioning Activities Report (PSDAR) to describe planned decommissioning activities and the schedule for those activities, provide an estimate of expected costs, and discuss the reasons for concluding that the environmental impacts associated with site-specific decommissioning activities are bounded by appropriate previously issued environmental impact statements, specifically NUREG 0586," Final Generic linvironmental impact Statement on Decommissioning of Nuclear Facilities" [ Reference 1] and the lladdam Neck Plant site specific Final Environmental Statement [ Reference 2] and Environmental Assessment [ Reference 3].

B A C K G it O U N D The IInddam Neck Plant (lINP) achieved initial criticality on July 24,1967, began commercial operation on January 1,1968, and operated 28 years achieving an overall capacity factor of approximately 70 percent. The nuclear steam supply system is a Ibur loop pressurized water reactor (PWR) designed by Westinnhouse Electric Corporation with a thermal power design limit of I825 MWt. The turbine generator was rated to produce 619 MWe.

i>eiueling began on November 13,1996 and was completed on November 15,1996, with all fuel assemblies being placed into the spent fuel pool fbr temporary storage. For economic reasons, CYAPCO opted to cease commercial operation of the IINP on December 4,1996. Certification of permanent cessa3on of operation and removal of fuel, in accord mce with 10CFR50.82(a)(1)(i) and (ii), was submitted to the U.S. Nuclear Regulatory Commission on December 5,1996 [ Reference 41 CYAPCO's primary goal is to decommission the IINP in a safe and cost effective manner.

CYAPCO will decontaminate and dismantle the llNP, resulting in the timely removal of the existing nuclear plant in accordance with one of the options found acceptable to the NRC in its Final Generic Environmental Impact Statement (FGEIS). The NRC regulations refer to this option as the DECON alternative resulting in prompt dismantlement of the site. Completion of the DECON option is contingent upon continued access to one or more low level waste disposal sites. Currently, the HNP has access to Chem Nuclear - Barnwell, South Carolina and Envirocare - South Clive, Utah. If there are any fbture changes in this regard, CYAPCO will infbrm the NRC of revised plans in accordance with 10CFR50.82(a)(7).

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• DESCRIPTION Ol'Pl.ANNED DECOMMISSIONING A CTIVITIES Ddorninissioning Activities and Planning The activities planned for decommissioning of the llNP reDect the selection of the DECON option for the site, CYAPCO will complete the detailed planning required for each decommissioning activity prior to the start of such activity.

Planning Activities (Prior to Subrnitial of the PSDAR)

The time period between the decision to permanently shut down and decommission the plant and the submittal of this PSDAR to the NitC has been utilized by CYAPCO to establish a decommissioning organization, prepare submittals for a revised Emergency Plan, a revised Security Plan, a revised Quality Assurance Program, revised Technical Speci0 cations, and to initiate planning for decommissioning activities.

Ongoing planning and preparation for decommissioning includes the following generalized types oftasks:

. Iteview existing plant programs to assess their applicability to decommissioning, e lleview and reclassify systems important to decommissioning operations,

. Revise procedures and license basis documents to reDect the plant's defueled and permanently shutdown con 0guration, e initiate radiological and hazardous material characterization of the site,

. Design and procure equipment and facilities to support decommissioning activities,

. Prepare detailed (area hy-area) work breakdown structures for decontamination / dismantling activities,

. Prepare a dose estimate for decommissioning activities, and

. Evaluate disposition options for facility components and structures.

A key step in decommissioning planning was the selection of a project staff and establishment of an organizational structure with prior decommissioning experience. This step mobilized key management personael with decommissioning experience, permanent CYAPCO management and stalTpersonnel, additional supplemental staff and specialty contractors (utilized as needed).

Plant Dismantlernent The decommiss;oning planning is based on selecting the DECON option and is expected to result in the decontamination and/or dismantlement of the majority of plant structures and facilities by the year 2004. The few facilities and structures that have to remain to oupport spent fuel and greater than class C (GTCC) waste storage will be decontaminated and/or dismantled after the spent fuel and G1 CC wastes are taken by :he DOE.

The following describes activities included in the dismantlement period:

. Establish site construction power distribution system,

. Pertimn primary systems decontamination, 2 l

• Perform asbestos abatement program, e Separate the fuel building from the rest of the site's mechanical and electrical systems,

, e Conduct decommissioning activities, including major component removal, e Conduct decontamination of facility surfaces, components and piping systems as required, e Conduct soil remediation as required, e Ship and properiv dispose of all remaining radioactis e materials, and e Perform compre.. nsive final status survey to demonstrate compliance with approved site release criteria [10CFR20, subpart E].

The structures and facilities that wi!! remain aller the dismantlement period to store the spent fuel and GTCC waste are as follows:

• The spent fuel building and the systems necessary to accomplish fuel cooling (Note:

modifications will be made early in the llNP decommissioning process to permit the spent fuel building and its fuel cooling systems to operate independently from the rest of the site),

e Support faci ities consisting of a control room, a security access point, and work areas necessary for spent fuel pool operations, and

. A security perimeter (e.g., security fence, an intrusion mon:toring system, lighting, etc.)

For present planning purposes it is assumed that wet storage will be continued until the spent fuel is shipped from the site. CYAPCO will appropriately advise the NRC of any future changes to its plans in this area.

MAJOR DECOMMISSIONING ACTIl'ITIES 10CFR50.2 defines major decommissioning as any activity that results in pennanent removal of major radioactive components (e.g., reactor vessel and internals, steam generators, pressurizer, large bore reactor coolant system piping, and other large components that are radioactive to a comparable degree), permanently modifies the structure of the containment, or results in dismantling components for shipment containing GTCC waste.

The following discusses the planned major decommissioning activities at the II'sP:

Reactor I'essel and internals The reactor vessel and internals are described in the Updated Final Safety Analysis Report (UFS AR) Section 5.3.

An engineering evaluation determined two technically feasible alternatives for removal of the reactor vessel and internals. These alternatives are (1) removal of the vessel (including reactor head) with the internals intact, and (2) segmentation of the internals followed by removal of the vessel (including reactor head). The schedule shown in Figure 1 for large component removal activities is expected to bound both the alternative of removing the vessel with the internals intact and the alternative ofinternals segmentation followed by vessel removal.

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1 Estimates of radionuclide concentrations in the vessel from neutron activation show that the limits for a 10CFR61 (disposal site) package will not be exceeded, and the specine activity of the

, package would be within the limitations for a 10CFR71 (shipment) package. This allows the vessel (including internals) to be qualified for normal conditions of transport, in both alternatives, the vessel (with or without the internals) would be shipped to a low level radioactive waste disposal facility inside an approved container.

Final alternative selection (expected 4th quarter 1997) will be based on an evaluation of parameters associated with project planning and execution, considering the following: safety impacta, personnel exposure, schedule impact, disposal facility availability, case of execution cost, and regulatory acceptance.

A portion of the highly activated reactor s essel internals, if segmented, will be characterized as GTCC waste. The GTCC material may be stored in the llNP spent fuel pool until it een be transferred to the DOE.

Stearn Generators The steam generators are described in UFSAR Section 5.4.

An engineering evaluation determined two technically feasible attematives for removal of the steam generators. These alternatives are (1) intact removal, and (2) partial segmentation. The l

schedule shown in Figure 1 is expected to bound either alternative.

Final alternative selection (expected 4th quarter 1997) will be based on an evaluation of parameters associated with project planning and execution, considering the following: safety impacts, personnel exposure, schedule impact, disposal facility availability, case of execution and cost.

Preunri:er The pressurizer is described in UFSAR Section 5.4.

The pressurizer will be removed intact in accordance with the general decommissioning activities and shipped to a disposal facility.

Reactor Coolant Systent (RCS) and Other Large Bore Piping The reactor coolant system and other large bore piping is described in UFS AR Section 5.4.

The RCS and any other large bore piping will be decontaminated as appropriate and removed in accordance with the general decommissionir.g activities.

Containonent The containment is described in UFSAR Section 6.2.

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The containment surfaces and structure (as appropriate) will be decontaminated and dismantled in accordance with the general decommissioning activities.

Spent Fuel Pool The spent fuel pool is described in UFSAR Section 9.1.

Once all spent fuel and any GTCC waste are removed from the spent fuel pool, the facility will be decontaminated and dismantled in accordance with the general decommissioning activities.

OTilER DEiCOMMISSIONING CONSIDliRA TIONS The decontamination and/or dismantlement of contaminated systems, structures and components may be accomplished by decontamination in place, dismantlement and decontamination, or dismantlement and disposal. A combination of these methods may be utilized to reduce contamination levels, worker radiation exposures and project costs. General considerations applicable to these activities are described below.

Chentical Decontantination of Printary Coolant Systents A chemical decontamination of the primary coolant systems will be perfbrmed prior to conducting major decommissioning activities. The chemical decontamination is a significant ALARA initiative being performed to reduce personnel exposure during decommissioning work actisities. The decontamination efibrt is expected to include the entire reactor coolant system (RCS)(including reactor vessel, steam generators and pressurizer) as well as portions of the following appended systems: letdown and charging, residual heat removal (RilR), loop till and drains, seal injection an<l return, and selected dead leg piping. Either the RCS pumps or the low pressure safety injecticn (LPSI) pumps will be used to provide the necessary decontamination flow. Modifications may be necessary to establish the required flow paths. The decontamination operation will be controlled by approved plant procedtm.

General Decomnuissioning Activities Relating to Rentoralof Radiological Contponents & Structures Components will be safely and efticiently removed using the techniques and methods determined to be the most appropriate for the particular clicumstances end as specified in engineering documents called decommissioning work packages. Openings in components will typically be covered and sealed to minimize the spread of contamination. The components may be moved to a processing area for volume reduction and packaging into containers for shipment to a processing facility for decontamination or a low level radioactive waste disposal facility.

Coi taminated concrete and structural steel components will be decontaminated and/or removed when contaminated and uncontaminated systems and equipment have been removed from the area or buitaing. The contaminated concrete will then be removed and packaged into containers for shipment to a low level radioactive waste disposal facility. Contaminated structural steel components may be moved to a processing area for decontamination, volume reduction and packagine into containers for shipment to a processing facility for decontamination or low level radioactive waste disposal facility.

Buried contaminated components (e.g., piping, drains) will be decontaminated in place or excavated. After excavation, the components will be examined to ensure that they are physically 5

I sound prior to cutting and removal. Appropriate contamination controls will be employed to minimize the spread of contamination and protect personnel.

Decontamination Methods Contaminated systems and components will be removed and sent to an off site processing facility or to a low level radioactive waste disposal facility. On site decontamination of systems and components will generally be limited to activities needed to maintain personnel exposure as low as is reasonably achievable, to expedite equipment removal, and to control the spread of contamination.

Application of coatings and hand wiping will be the preferred methods for stabilizing or removing loose surface contamination. If other methods are utilked (e.g., grit blasting, high pressure water), airborne contamination control and waste processing systems will be used as necessary to control and monitor any releases of contamination.

Contaminated and activated concrete as well as other contaminated materials will be removed and sent to a low level radioactive waste disposal facility. Removal of concrete will be performe<l using a method which controls the removal depth to minimize the waste volume produced (e.g., scabbling, scarifying). Vacuum removal of the dust and debris with IIEPA tiltration of the effluent will be used to minimize the need ihr additional respiratory protection control measures.

These methods are the most practicable and widely utilized at this time. Ilowever, as new decontamination technologies are developed, they will be considered and used if appropriate.

Disnmntlement Methods Dismantlement methods can be divided into two basic types:

• Mechanical Methods - Mechanical methods machine the surfaces of the material that is being cut. These methods typically are capable of cutting remotely without generating significant amounts of airborne contamination. This attribute makes these mchods attractive for most of the contaminated piping, equipment, and components that wih be removed at the llNP.

The outside diameter machining method is best suited ihr cutting large bore contaminated piping. Smaller bore contaminated piping, tubing, and : oports can be cut using any of the mechanical methods (e.g., band saws, reciprocating saw idraulic shears).

• Thermal Methods - Thermal methods melt or vaporize th rfaces of material that is being cut. The cutting debris is transported from the cut region n a gas jet or water spray.

Although thermal methods are significantly quicker than n .chanical methods, they have high power requirements and generate airborne contamination w aen used on contaminated systems in air Generation of airborne contamination can be easily controlled when the method is used underwater. Thermal methods are suitable for segmenting large vessels in areas that can easily be sealed, filtered, or maintained underwater. The method is also suitable fo. use at a cutting station with air filtration. Thermal methods are appropriate for removing structural steel ifit has been decontaminated or if a local contamination envelope with IIEPA filtration is established. Appropriate lead paint removal controls must also be implemented.

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These methods are the most practicable and widely utilized at this time. liowever, new dismantlement technologies developed prior to the commencement of actual decommissioning activities will be considered and used if appropriate.

Specialor Unusual Progrants

'lhere are no special or unusual programs. All procedures and processes that will be used at the llNP are consistent with those considered in the Final Generic Environmental impact Statement (FGEIS).

Removal of Low Level Railloactive Il'aste (LLil') anti Compaction or incineration LLW will be processed in accordance with plant procedures and sent to LLW disposal facilities.

Some LLW may be incinerated off-site at a licensed facility. No incineration will occur on site.

Onsite compaction is not expected to be used at this time.

SollRerneillation Soils and pavement will be suseyed and characterized in accordance with the site radiological characterization program. As necessary, soils and pavement will be remediated (i.e., iemoved, processed and disposed of at a licensed facility) if determined to contain contamination levels above the NRC site release [10CFR20, subpart El guideline values.

Processing anel DisposalSite Locarians Currently, there are several facilities available for (1) the processing of waste materials to achieve volume reduction prior to disposal or (2) the disposal oflow level radioactive waste.

These locations include (but are not limited to) Chem Nuclear - Barnwell, South Carolina; Envirocare - South Clive, Utah; Scientific Ecology Group (SEG)- Oak Ridge, Tennessee; llake

- Memphis, Tennessee; and US Ecology - Oak Ridge, Tennessee.

Removalof Alixett Il'astes Mixed wastes will be managed according to all applicable federal and state regulations including NRC handling, storage, and transportation regulations.

Mi <ed wastes from the IINP will be transported only by authorized and licensed transporters and shipped only to authorized and licensed facilities. If technology, resources, and approved processes are available, processes will be evaluated to render the mixed waste non-hazardous.

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Storage / Removal ofSpent Fuel and GTCC Waste Spent fuel and GTCC waste are currently planned to be stored wet in the spent fuel pool for the duration of the decommissioning until the DOE is ready to take such waste. Since the availability of a licensed DOE high level waste repository is uncertain, a precise determination of when spent fuel and GTCC waste will be removed from the llNP site is not possible. Current projections are that the turnover of spent fuel and GTCC waste to the DOE will be completed by January 2022 (based on an initial shipment start date in January 2006 and DOE's current y acceptance schedule). CYAPCO will appropriately notify the NRC of any changes to its plans in this area.

SITE RESTORA TION Followir.g dismantlement and decontamination of structures, systems, and components in a given work area, the structures ano area will be surveyed to demonstrate that they meet NRC site release criteria [10CFR20, subpart E]. Successful completion of this survey in conjunction with oversight and confirmatory surveys by the NRC will allow remaining structures, systems, and components to be released for ur..estricted use.

Following transfer of spent fuel and GTCC waste to a DOE facility (or to dry storage), structures, systems, and components used to support wet spent fuel storage will be decontaminated and/or dismantled. The portion of the site that has not yet been surveyed will be surveyed to demonstrate that it meets NRC site release criteria [10CFR20, subpart E]. Successful completion of this survey will allow remaining components and structures to be demolished by conventional methods. Ultimately, CYAPCO's license for the site will be terminated, and the site will be released for unrestricted use.

SCllEDULE FOlt DECOhlh11SSIONING ACTIVITIES Figure i presents the schedule and mi'estones for major decommissioning activities. This schedule is based on the assumption that spent fuel and GTCC waste will be retained in wet storage until the L OE transfers such waste to an offsite facility (as stated above, for planning purposes, this is considered complete in 2022). Activities requiring significant NRC licensing effort and resources are also shown on Figure 1.

ESTIh1 ATE OF EXPECTED DECOhlh11SSIONING COSTS In December 1996, CY APCO filed an updated decommissioning cost estimate [ Reference 5]

with the Federal Energy Regulatory Commission (FERC). The decommissioning cost estimate was updated to reflect a pricing structure change for low level radioactive waste disposal et flamwell, South Carolina, new industry experience in asbestos abatement, contaminated soil remediation activities, new industry experience in the final site survey, and scope of primary systems decontamination to lower exposures to workers during decommissioning. The current estimated cost to complete decommissioning is $426.7 million in 1996 dollars. CYAPCO will submit a further update on decommissioning funding matters, in light of the FERC rate case developments, in accordance with 10CFR50.82(8)(iii) and 50.82(c).

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4 The current 1996 updated estimate, which will be identified as CY/FERC 96,is the basis for- 4 current IINP_ decommissioning plans and considered all decommissioning options DECON, SAFSTOR, and ENTOMB. The CY/FERC 96 submittal assumes prompt removal / dismantling, (DECON), and is based on an analysis of the llNP systems, components, and structures. The estimate is also based on the radioactive waste disposal options available to CYAPCO in late

!- 1996 (e.g., alternative waste disposal sites, barge transport, and vari _ us radwaste reprocessors).

This estimate also includes provisions for site restoration, and for storage of spent fuel and 3- GTCC wastes on the llNP site until 2022.

The CY/FERC-96 decommissioning cost estimate, expressed in terns of 1996 dollars, is summarized as fbliows:

e Pianning/ Preparation $ 76,248,000*

e I.arge Component Removal 46,550,000-e Dismantlement Activities 149,655,000 e 1.ow Level Waste Shipping /Durial 71,928,000

*- Spent Fuel Storage 3.22419n0 e Total Cost te Remove / Dismantle CY $426,726,000 3

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• Includes asbestos abatement, RCS decon, & SFP island l: An extemal sinking fund, in accordance with 10CFR50,75(e), was established in April 1984, and

! amended in 1987, to accumulate CYAPCO decommissioning funds. Certification was provided in July 1990 [ Reference 6] to certify the obligation of each wholesale purchaser from CYAPCO

to be responsible ihr its share of the llNP decommissioning costi pursuant to the terms of the F

power contracts.

ENVIRONMENTAL IMPACTS d

CY APCO has performed an environmental review to evaluate all actual or potential

! environmental impacts associated with the proposed decommissioning activities, This evaluation used as its basis NUREG 0586," Final Generic Environmental Impact Statement (FGEIS) on .

7 Decommissioning of Nuclear Facil.ities,"[ Reference 1] and two previous site-specific

- environmental assessments from the conversion of the provisional operating license to a full-term

[ operating license [ Reference 2], and most recently, from the re-capture of the construction period

- time duration [ Reference 31 ,

This environmental review concludes that the impacts due to decommissioning of the IINP will

- be bounded by the previously issued environmental impact statements, specifically the FGEIS and previously issued environmental assessments This is principally due to the following reasons:

The postulated impach, associated with the method chosen, DECON, have already been

- considered in the FGEIS.

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e There are no unique aspects of the plant or decommissioning techniques to be utili7ed that would invalidate the conclusions reached in the FGEIS.

The methods to be employed to dismantle and decontaminate the site are standard ,

construction based techniques fully considered in the FGEIS .

The site specific person-rem estimate fbr all decommissioning activities has been conservatively calculated using methods similar to and consistent with the FGEIS.

Specifically, this review concludes that the llNP decommissioning will result in generally positive environmental effects, in that:

Radiological sources that create the potential for radiation exposme to site workers and the public will be eliminated.

The site will be returned to a condition that will be acceptable for unrestricted use.

The thermal impact on the Connecticut River from facility operations will be eliminated.

Noise levels in the vicinity of the facility will be reduced.

llazardous materials and chemicals will be removed.

Local traffic will be reduced (fewer employees, contractors and materials shipments than are required to support an operating nuclear power plant).

Furtheimore, the 1INP decommissioning will be accomplished with no significant adverse environmental impacts in that:

No site specific factors pertaining to the llNP would alter the conclusions of the FGEIS.

Radiation dose to the public will be minimal.

Radiation to decommissioning workers will be a fraction of the operating ex perience.

Decommissioning is not an imminent health or safety problem and will generally have a positive environmental impact.

The total occupational radiation exposure (excludes public and trans;rartation dose) impact for the proposed decommissioning activities has been conservatively estimated at approximately 935 person-rem, which is less than the 1,115 person-rem exposure estimate of the FGEIS for a PWR.

This estimate is conservative and is based primarily on January 1997 plant dose rate surveys with no credit for (1) decay in niace ofisotopes (such as Co-60 ), (2) sequenced removal of higher dose rate components first,(3) aggressive ALARA program initiatives,(4) increased worker efliciency with experience, or (5) smaller scale decontamination initiatives.

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Radiation exposure due to transportation of radioactive waste (includes both occupational and offsite radiation exposures) has been conservatively estimated The occupational exposure is

, approximately 61 person-rem. The cumulative radiation exposure to on lookers and the general public is approximately 11 person-rem. These values are bounded by the FGEIS values of 100 person-rem for transportation occupational exposure and 21 person-rem for the general public exposure.

Radiation exposure to off site individuals for expected conditions, or from postulated accidents, is bounded by the Environmental Protection Agency's Protective Action Guides and NRC regulations. Doses due to the release of radionuclides in eftluents will be negligible in comparison to allowable limits.

No significant impacts are expected from the disposal oflow level radioactive waste. The total volume ofIINP low level radioactive waste for disposal has been estimated at 283,117 cubic feet which is well bounded by the FGEIS volume of 647,600 cubic feet The actual IINP volume may be further reduced by additional utilization of volume reduction techniques.

Finally, the non-radiologic d environmental impacts from decommissioning are temporary and are not significant. The largest occupational risk associated with decommissioning IINP is related in the risk ofindustrial accidents. The primary environmental effects are short term, small increases in noise levels and dust in the immediate vicinity of the site, and truck traffic to and from the site for hauliag equipment and waste. No significant socioeconomic impacts, other than those associated with cessation of operation (loss ofjobs and taxes), or impacts to local culture, terrestrial or aquatic resources have been identified.

Given the low level of contamination and the expected volume of waste, disposal oflow level radioactive waste off-site in a timely manner should be possible. If for any reason some portion of these wastes needs to be stored temporarily on site, adequate space exists. No significant environmental impacts are anticipated from temporary on-site storage because all applicable federal and state regulations will be complied with.

IlEFERENCES

1. NUREG-0586," Final Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities," August,1988.

2. USNRC, Final Environmental Statement, Haddam Neck (Connecticut Yankee) Nuclear Power Plant, Docket No. 50-213, October 1973.

3. Letter, USNRC to CYAPCO," Environmental Assessment for Proposed License Extension," dated November 23,1987.

4. Letter, CYAPCO to USNRC,"lladdam Neck Plant Certifications Of Permanent Cessation Of Power Operation And That Fuel llas Been Permanently Removed From The Reactor," dated December 5,1996.

5. " Decommissioning Cost Study for the Connecticut Yankee Nuclear Power Plant," dated December,1996.

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, 78

.6- . Letter, CYAPCO to' USNRC," Decommissioning Financial Assurance Certification

. Report," dated July 18,1990, T

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Figure.1 . 2 CY Decommissioning Schedule D6 1997 1998 1999 2000 2001 2002 2003 2004 2005~ 2006- 247 -2005 10 Task Name - Jc' Jan l Jtt jen l Juf Jan l Jul Jan l Jul Jan l Jul Jan j Jul . Janl Juf Jan l Jul Jan l Jul Jan! Jul Jan l Jul ' Jan l Ju8 1- Decommissioning Planning ,g  ;

2 Defueled Ucense Amendments g; i 3 Defueled Programs (QA, Securdy, & EP) ,

g 3 4 PSDAR g

5 Updated FSAR g  !

6- Scoping Survey /Sde Charactenration g .gg g ,g . ; a ;g, . c.-g '

7 Vtn Coolant System Decon I -

8 SFP island /Repower Modifications .

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9 Asbestos Abatement I j b.wr M4.. h. ds , ,

Large Component Removal (Rx vessel, intempts, SGs, Prz) 10

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11 Secondary SW Removal  !

g E.memyyl.. .

-n 12 ' Contaminated System Removals $

! [.,;;,e w ,]fd 13 Main Coolant System Rerroval  ;

14 RCA BurkJing Decon/ Removal I m .-..._s b< m,. w :Sjjl 15 Containment Decon/ Removal -

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16 License Tenwnation Plan g

, 17 Soil Remediation gTM l Er s . :q 18- Final Site Survey - Phase i 1 %,zd.

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I- 19 Spent Fuel Storage (Projected to 2022) -m-

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k. w5  :.&;[ . .; h -? _:w, M =4N M &.a x.;

w ~;;2~3f :_:szw mz xx_ ;_ x,w, l 20 SFP Decon/ Removal (Start 2022) 1

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! 21 - Final Site Survey - Phase 11 (Start 2022)

I; 22 License Termination (Jan.1.2023) ,

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