ML20127N399

Revised SER Supporting 920522 Application for Amend to License SNM-368,adding Septic Leach Field Decommissioning Plan

ML20127N399
Person / Time
Site:	07000371
Issue date:	11/16/1992
From:	Joseph Austin, Jack Parrott NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:
Shared Package
ML20127N397	List: ML20127N395 ML20127N399
References
NUDOCS 9212010238
Download: ML20127N399 (5)

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.S DS Caog'g UNITED STATES

[ g NUCLEAR REGULATORY COMMISSION

p p WASHlh,GTON, D. C, 20555 k*...,/ NOV 10 m?

DOCKET N0: 70-371 LICENSEE: 'UNC, Inc. '

Naval Products Division Montville, Connecticut

SUBJECT:

REVISED SAFETY EVALUATION REPORT, AMENDMENT APPLICATION DATED MAY 22, 1992, REGARDING ADDITION OF SEPTIC LEACH FIELD DECOMMISSIONING PLAN BACKGROUND On June 10, P G UNC, Inc. (UNC) submitted the UNC Naval Products Decommissioning Plan. The portion of this plan dealing with the decommissioning of the buildings and the outdoor areas, with the excention of the 1991.septic leach fields, was subsequently approved by letter dated October-3,-

Attachment A to this plan, which deals with the decommissioning of the septic leach fields, was revised in response to NRC answers to UNC questions regarding the septic leach field decommissioning and a meeting between UNC and NRC on December 5, 1991.

was resubmitted by letter dated The December Septic Leach-Field Decommissioning Plan (SLFDP) 20, 1991, and commented on by the NRC's Division of Low-level Waste Management and Decommissioning by letter dated February 11, 1992. Attachment A was again revised by the licensee and resubmitted by letter dated May 22, 1992.

On September 8,1992'the NRC staff issued a Safety Evaluation Report (SER) for the UNC amendment application dated May 22, 1992. In that SER, the staff-recommended incorporation of a license condition that would not allow the use of the UNC proposed monetary limit of $25,000 per person-rem averted for an As low As Reasonably Achievable (ALARA) analysis. Upon further reflection, the staff believes that the UNC prcposal is a reasonably conservative bounding value in support of. an ALARA analysis. Therefore, even though NRC has not established a monetary value for ALARA in decommissioning situations, the staff believes that the UNC proposal for ALARA analyses is an acceptable approach. 'Accordingly, this revised SER does not include the license -

condition recommendation contained in the September 8, 1992 SER. This revision does not effect the Finding of No Significant Impact (57 FR 38071).

DISCUSSION Beginning in early 1974, affluents, contaminated with low-levels of high.

enriched uranium, were discharged, under NRC license, to an onsite septic leach field. In 1979, an additional septic leach field was added.

Use of this combined leach field continued until November 1987 when UNC began discharging their contaminated effluent to the Montville sewer system per NRC license condition.

The objective of this proposed addition to the SLFDP is to allow for the decontamination and decommissioning of the septic leach fields at the UNC Naval Products Site in Montville, Connecticut.

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UNC, Inc. 2 0 01/ 1 c L Septie Field Description Septic Field 1 Septic Field I has an area of about 6600 m2 and is located immediately to the south of the facility. This field was fed by a main incoming line which led to a master distribution box. At this point the waste stream was split into two pairs of parallel feed lines which ran the length of the field. The leaching was accomplished by a series of leaching pipes (laterals) consisting of 43 parallel 10 cm diameter plastic pipes varying in length from 30 to 60 m and separated by a distance of about 2.5 m. Each lateral had a series of holes at the bottom, about 10 cm apart, which permitted the material to leach into the ground. Each lateral was laid in a crushed rock filled trench about 60 cm deep and 75 cm wide. Each trench was covered by at least 60 cm of cover. The crushed rock in each trench, which assisted in the leaching, was about 3 cm in diameter.

Septic Field 2 Septic F. eld 22 lies immediately south of Septic Field 1 and has an approximate area of 2200 m . This field was fed by a line which was also connected to the master distribution box. From there, a feed line ran to a secondary distribution box. Two lines led from this second box, each to a third box.

Each of the two tertiary distribution boxes fed six drywells positioned around each box. The 12 drywells were perforated concrete cylinders each 2 m in diameter, 3.7 m high, and buried at least 1 m underground. Approximately 60 cm of 3 cm diameter crushed rock surrounded each drywell to aid in the leaching process.

Both the laterals and the drywells contained sludge contaminated with high enriched uranium. After stripping off the cover, UNC has removed the sludge, laterals, and drywells to an approved low-level waste repository. In addition, UNC will characterize the residually contaminated soil in the septic fields, in the manner specified in the SLFDP, and remove any contaminated soil so that the average concentration of the _ residual contamination is not greater than the option 1 levels for enriched uranium (30 pCi/g) set forth in the 1981 Branch Technical Position (BTP) entitled " Disposal or Onsite Storage of Thorium-or Uranium Wastes From Past Operations" (46 FR 52061).

Soil Samolina Field 1 After removal of the laterals, UNC sampled the stone in the trenches at 10 m l intervals per guidance from NRC in a latter dated October 24, 1991. The l licensee has also sampled under the junctions of the main distribution pipe  ;

with the leach field laterals. In addition, UNC will measure external j radiation levels from each trench to identify any significant hot spots. l

-Twelve locations under the laterals were sampled at 15 cm intervals to 30 cm '

and then at 60 cm intervals down to the water table.

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o UNC, Inc. 3 NOV le -r Field 2 The sail above and below each drywell has been sampled through to the water table. Holes were bored at these locations, and soil samples taken every 60 cm. Af ter removal of the drywells and the sludge within, the resulting exposed soil surface was sampled. The stone surrounding each drywell was i

sampled at five locations (two samples above the sludge line and three below) for each drywell before the drywells were removed. After backfilling, each former drywell location will be resampled, at 60 cm intervals, through three

vertical cores to the water table. Analysis will be of composite samples from 0-6 ft, 6-12 ft, and 14-20 ft. A sample will also be taken from the 12-14 ft interval. This sample contains the drywell sludge interface and will not be composited.

Ground-water Sampling Ground-water sampling will be performed using existing wells and additional new wells. These additional wells have been located and drilled in accordance with the hydrologist's specifications, and will be used to characterize the ground water. The hydrologist's reports will be appended to the final site survey report.

Analysis 4,

i All soil semples will be measured for gross alpha. Isotopic uranium analysis will be performed on samples whose total gross alpha activity exceeds approximately 75% of the 30 pCi/g limit-including background. For water, isotopic analysis will be performed on all samples whose gross alpha readings exceed 15 pCi/1.

Final Disposition of Septic Fields

' On the completion of all remedial actions, measurements, and- analysis necessary to demonstrate compliance with criteria specified in this plan, UNC will act to prevent subsequent " mining" of the remaining stone by deep plowing Field I to intermix the stone with soil. Finally, both fields will be covered with at least 1.5 m of clean soil.

Nuclear Criticality Safety The amount of concentrated Special Nuclear i4aterial (SNM) on site is now below that which requires a physical security plan (<l5 g). The concentrations of high enriched uranium measured in the septic leach fields are in the tens of pCi/g range which is many times below the concentration required for this to be a criticality safety problem.

Radiation Safety The existing radiation protection program will be applicable and extended to cover the decontamination and decommissioning activities. The program 4

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UNC, Inc. A liOV 1 n includes a system for controlling and assessing the workers' external and internal radiation exposures, surface contamination in the work areas, and effluent releases. The pronram also includes action levels and action to be taken to reduce radiation exposure.

Environmental Safety This license amendment request was evaluated with an Environmental Assessment which concluded with a Finding of No Significant Impact. Therefore, it is not anticipated that granting this request will involve significant impact to the environment.

CONCLUSIONS The above descriptions of survey techniques and residual contamination disposition in the septic leach fields are based on guidance provided in the BTP and discussions and correspondence with NRC staff. Based on the above descriptions, tne staff concludes that the amendment can be issued to authorize the final decontamination and de:ommissioning of the UNC septic leach fields without undue risk to workers, public, or the environment.

Approval of the amendment is recommended.

The Region I Project Inspector had no objection to this proposed action.

Jack D. Parrott Facilities Decommissioning Section Decommissioning and Regulatory Issues Branch Division of Low-Level Waste Management and Decommissioning, NMSS Approved by: /.9 John H.lustin, Chief Decommissioning and Regulatory Issues Branch Distribution: Docket No.70-371 NRC Central File NMSS r/f LLDR r/f JParrott LBell TCJohnson MWeber JAustin WBrach RBangart JRoth,RI JSurmeier JCopeland PDR YES %

PDR NO Category: Proprietary or CF Only ACNW YES N0 g SUBJECT AB5 TRACT: Revised SlR for UNC, Inc, license amendment no. 23 Docket No.70-371 *see previous concurrence OFC LLDR* LLDR* LLDPk LLDh)

NAME JParro+t JCopel and LBe JAu[t$n

,DATE _ 10/26/92 10/26/92 11 /,M/92 /// //g92 ti: \UNCSER2.JDP OFFICIAL' RECORD COPY l

UNC, Inc. 4 Radiation Saf fy The existing radiation protection program will be applicable and extended to cover the decontamination and decommissioning activities. The program includes a system for controlling and assessing the workers' external and internal radiation exposures, surface contamination in the work areas, and j effluent releases. The program also includes action levels and action to be taken to reduce radiation exposure.

Environmental Stf ety

. This license amendment request was evaluated with an Environmental Assessment which concluded with a Finding of No Significant Impact. Therefore, it is not anticipated that granting this request will involve significant impact to the environment.

j CONCLUSIONS l The above descriptions of survey techni_ ques and residual contamination j disposition in the septic leach fields-'are based on guidance provided in the BTP and discussions and correspondence with NRC staff. Based on the above descriptions, the staff concludes that the amendment can be issued to authorize the final decontamination and decommissioning of the UNC septic leach fields without undue risk-to workers, public, or the environment.

Approval of the amendment is recommended.

The Region I Project Inspe.ct'or had no-objection to this proposed action.

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Jack D. Parrott Facilities Decommissioning Section Decommissioning and

Regulatory Issues Branch

! Division of low-Level Waste Management and Decommissioning, NMSS Approved by:,

John H. Austin, Chief Decommissioning and Regulatory Issues Branch i

l Distribution: Docket No.70-371 NRC Central file NMSS r/f LLDR r/f JParrott TCJohnson MWeber JAustin WBrach RBangart JRoth,RI PLohaus JSurmeier JCopeland i

PDR YES PDR NO Category: Proprietary or CF Only

, ACNW YES NO SUBJECT AB3 TRACT: Revised 5ER~for UNC, Inc. license amendment no. 23 Docket No.70-371., m 0FC LLDR k[ LLDR h LLDR LLDR NAME JParrhtt JCopeland TCJohnson JAustin l- DATE /0/ S /92 to /L6 /92 / /92 / /92

! 0FFICIAL RECORD COPY G:\UNCSER2.JDP l

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i I- SEP 'O 8 892 UNITED STATES NUCLEAR REGULATORY COMMISSION ENVIRONMENTAL ASSESSMENT l

j OF PROPOSED FINAL DECOMMISSIONING OF THE

SEPTIC LEACH FIELOS M UNC. INC,. NAVAL PRODUCTS SITE

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DOCKET NO.70-371

$; UNC. INC.

I The U. S. Nuclear Regulatory Commission is considering the approval of the

decommissioning of the septic loach fields at the UNC, Inc. (UNC) Naval Products facility in Montville, Connecticut.

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.Procosed Action: The proposed action is the issuance of a license amendment l

authorizing UNC to perform final decommissioning of the septic leac' fields.

l Begirning in early 1974 effluents, contaminated with low-levels of high enriched uranium, were discharged, under NRC license, to the onsite septic -

i leach field. This field consists of 43 parallel perforated 10 cm diameter plastic pipes (late-als) varying in length from 30 to 60 m ad separated by a i

ciistance of about 2.5 m. Each lateral is laid in a gravel tilled trench about

! 60 cm deep and 75 cm wide.

t Each trench is covered by at least 60 cm of cover, In 1979, an additional field was added to this septic. system.. This field i

i consists of 12 dry Mis which are perforated concrete cylinders each 2 m in diameter, 3.7 m high, and buried at least 1 m underground. Use of this t_

combined leach field continued until November of 1987 when UNC began L discharging their contaminated effluent.to;the Montville sewer system per NRC license condition. 1 i

Both the laterals and the dry wells contain sludge contaminated with high

! enriched uranium. - UNC will. remove this sludge, the laterals and the dry wells to an approved low-level waste repository. In addition, UNC will characterize i

the residually contaminated soil in the-septic fields, in the manner specified

! in the septic field decommissioning plan (attachment A to UNC Naval ~ Product Decommissioning Plan), and remove contaminated soil from the leach fields so that the average concentra+ ion of residual contamination in the septic field i is below.the FR_52061). levels set furth in the 1981 Branch Technical Position (BTP) (46 a

~The septic fields have~been gridded into 100 m . sections. The licensee is-i being allowed to average the concentration o contamination found in the trenches or drywells contained in between the trenches in grid theblock.100 m,each 100 m[ grid block ove qu .

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I j Need for the Prooosed Action: The proposed action is net.essary so that UNC can characterize and remove radioactive piping and soil from the septic leach l fields and release the area for unrestricted use.

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i Environmental Imoacts of the Procosed Action:

i For this proposed act..n, UNC f has stated that they will reduce the average level of residual contamination in each septic field grid block to below the option 1 level (30 pCi/g) for enriched uranium specified in the BTP. The dose basis for the BTP residual i

contamination level is that the highest estimated dose from option 1

! concentrations of insoluble high enriched uranium is bounded by the j- approximately 20 mrem /yr to the lung an individual would get through the inhalation pathway.

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Doses to workers from exposure during removal of contaminated pip; and soil from the septic fields will be limited by 10 CFR Part 20.

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Conclusion:

On the basis -of the NRC staff's evaluation of the app' n. ant's i

j Septic t.each Field Decommissioning Plan, and the fact that it compiles with j

the BTP residual concentration limits, the staff concludes that the proposed action will not result in any significant environmental impact.

i Alternatives to the Prooosed Action: Alternatives to t5e proposed action include; 1) the no action alternative, and 2) the removal of all residual contamination to background levels. The no action alternative would leave i

j soil on site contaminated with high levels of enriched uranium. This could pose a unacceptable health and environmental risk in the future. Therefore, the site could not be released from its NRC license. This is not an acceptable solution- from a human health and safety, environmental, and -

licensing standpoint. The removal of all residual contamination to background levels would lead to higher disposal costs, estimated at an additional.

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$2,000,000, a cost passed on to U.S. taxpayers because site decommissioning is being funded by the U.S. Department of Energy. In addition, excavating and

! shipping all residual contamination to a low-level radioactive waste i

repository would lead to an in:reased potsibility for inhalation doses, onsite occupational accidents and transportation accidents. Therefore, this i

i alternative is not acceptable frous a cost-benefit, and health and safety standpM nt.

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Alternative Use of Resources: The proposed action would-result in the

- irreversible use of energy resources in the conduct of decommissioning

- activities und'the transportation of waste materials for disposal. L A small

- amount of land at the low-level waste disposal site would be. irreversibly committed for waste disposal. There are no reasonable alternativas to these resource uses, and the proposed action does not involve any unresolved l -

conflicts concerning use 'of available resources.

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'Aaencies and Persons Co d ed, and Sources Used: This Envir mental Assessment was prepared entirely by staff of the U.S. Nuclear Regulatory Commission. No other agencies or persons were consulted. No other sources were used beyond those re4renced in this Environmental Assessment.

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Jack D. Parrott, Project Manager Facilities Decommissioning Section Decommissioning and Regulatory issues Branch Division of low Level Waste Managreent and Decommissioning, NMSS Approved by: [d I Jot (n H. Austin, Chie' ,

Decommissioning and Regulatory issues Branch 3

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Fedacal Regis.ar / Vol. 57. No.183 / Friday. Augual 21. S992 / Nortoes segy

' Nome of Commitfew Advisory preparation of an EnvironmentalImpaet (1) ne a pplicant. UNC. Inc. 'to the Committee for Mathematical and Statement. Acturdindy,it has been attention of Mr. George it Waugh.

Physical Sciences, determined that a Findmg of No Generel Manager. UNC Noval Products.

Purpose-To provide advice. Significant Impact is appropriate. 67 Sandy Desert Road. P.O. Box 981 recomendation, and ovenight no Environmental Assenroemt is Uncasville. Connecticut Ou3824X)?.2; and cowrnmg NSPs Mathematical av"llable for public inspection and Physics. Astronomy. Matertals and (2) ne NRC staff, by delivery to the tapying at the Commission's Public F.xecutive Director for Operations One Chemistry programs st1Mce on policies Docu nent Room. 1717 11 Street. NW..

and d.rections MPS programs in achce Wash ngton, DC. Copies of the W alte Flint North.11555 Rockville Pike.

Rockville. MD 20852, or by mail and education should follow: provide Environmental Assessment may be advice on effective and rSient addrened to the Executrve Director foe obtained by calling (301) $w2%5 or by Operetions. U S Nuclear Regulstory strategies for achieving o W orogram writing to the Decommissioning and Commission. Wa shington. DC 21655.

escel ence, the appropria n .s of Regulatory issues Dranch. Division of Any hearing that is requested it;d current disciplinary boundanes: help to law. level Weste and Decommluloning. granted will be held in accordance with define the moat effective investment U S Nuclear Regulatory Commission, the Commission's Informal llearing strategies: judge the success of the Washington, DC 20555. Procedures for Adjudications in programs, and other appropriate aspects ne Commission hereby provides Mater %I Licensing Proceedings in 10 of program performance. notice that this is a proceedmg on an CFR pe.t 2. subpart L Balacced Afembership Plans. The app'ocation for a license amendment Advisory Committee for I-uthematical For further details with respect to the falling within the scope of subpart L. proponed action, see the licensee's and Physic.nl Sciences w.d be composed Informallleiring Procedures for request for license amendment dated of up tc.12 individuals with national Adjudica*lons in Materials LJcensing stature in sci 9nce, technology and May 22.1992, which is avallable for lYoceedings, of the Commission's Rules inspection at the Commission's Public educattort Attention wdl be given to of Practice for Domestic IJeensing geographical distnbution and the Document Room. 2120 L Street N W.,

Proceedings in 10 CFR part 2. Pu suant Washington. DC.

participation of individuals frtin to i 2.1205(a) ary person whose underrepresented groups. Interests may be affected by this Dated at Rodvtile. Maryland. this 14th day i

Representatives of the Divisional of August.1991 proceeding may file a request for a Advisory Committees wdl serve as en hesaing in accordan~ with l 2.1205(c). For the US Nadear R # story 1

officio member s. Commlulon.

A request for heart g . wet be filed Ilcepom,ible NSF O#iclo/s: Dr. within thirty (30) days of the date of IoheIL Austin.

!!iam C arns or Dr. jut *h Sunley. publication of this Federal Register nonce.

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j '/$,f, Date L August 18.19ul Managernent and Drwmmiss tuntre. NMSS.

De request for a hearing must be M. a.heoca Wlause.

gpg g ggg pgg,g 7 g g ,fpg filed with the Office of the Secretary _ , , , ,

Committee Mancgernent Officer, either-(FR Doc. s2-19aa1 riled 6-20-et a n u (1)IJy delivery to the Docketing and -

,,,,,,,m Service Branch of the Office of the Advloory Cornmittee on Reactor Secretary at One White Flint North. Safeguasda. Secs;r T.mee on

_ _ _ - . " 11555 Rockville Pike. Rockvilla. MD Advanced Bomng Watee Rortors; NUCLEAR REQULATORY 20n52;or Revised Notice of Meeting CCWISSION (2) Dy mall or telegram addrewed to l the Secretary. U.S Nuclear Regu!atory A portion of the ACRS Subcomminee (Docket No. 70-3711 Commission. Washingtork DC 20%5. meetmg on Advanced Boiling Weter Finding of No $4nh Wect Attention: Docieting and Servir4 Reactors scheduled for August la. Iw2 Con Branch will be closed as necenary to discuss j Mn of Amendment to WC' la addition to meeting applicable Proprietary Information (5 U S C.

i Ucense and Oppwknq w l **9 rquirements of to CFR part 2 of the 552.b(c)(4)k All other items pertaining to Commluion's regulations, a request foe this meeting remain the same as l

The U.S. Nuclear Regulatory a hearing filed by a person other bn published previously in the Feder al Commission (the Commission)is the applicant must describe in den.h Register on Tuesday. August 1.19M (57 constdenng an amendment of Special (1) ne interest of the requestor in the FR 34321k Nuclear Material License No. SNM-368 proceedmgs: Further information regarding topics tc permit UNC. Inc. (UNC) to leave low. (2) }{ow that interest may be affected to be discuased, the scheduing of l

levels of residual high-enriched uranium by the resulta of the proceeding sessions open to the public, whether the l contaminstion ensite in their septic including the reasons why the requestor meeting has been cancelled or teach fidds after decommissioning. should e.bmit a hearing, with particular rescheduled, the Chairman's ruhng on The Commission's Division of Low. reference to the factors set out in requests for the opoortumty to present Level Waste Management and i 1.1205(e k oral statements and the time ellotted Decummissioning has prepered an (3)Th. equestor's areas of concern therefor can be obtained by a prepaid Environmental Assersment related to about the dcensing activity that is the telephone call to the cognizant ACRS the amerdment of Speelal Nuclear subject matter of the proceeding: and staff engineer. Mr. Elpidio Igne Material IJcense No. SNM-368. On the (4) ne circumstances establisMng (telephone 301/492-4192) betweert 7 30 basis of this assenment the that the request for a hearing is timely in a.m. and 4:15 p.m. (E.s.t.). Persons l Cornmission has concluded that the accordance with l 2.1205(ck planning to a.tnd this meeting are j

eavironmental1:npact created by the Each request for a hearing trust also urged to contact the above narned l prcposed licensing action would not be be sen ed. by delivering it personally oc - ind.vidual one or two days before the sigmficant and does not warrant the by snail to: scheduled meeting to be advimi of any 1

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