ML20198R230

Forwards Environ Rept Prepared in Preparation for Proposed Decommissioning of UTR-10 Reactor,Per 10CFR51.21

ML20198R230
Person / Time
Site:	University of Iowa
Issue date:	01/04/1999
From:	Wendt S IOWA STATE UNIV., AMES, IA
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20198R218	List: ML20198R213 ML20198R221 ML20198R230 ML20198R254 ML20198R265 ML20198R278
References
NUDOCS 9901080131
Download: ML20198R230 (4)

Text

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,. n IOWA STATE UNIVERSITY [1"n""fs"<*'11 Enginening OF SCIENCE AND TECHNOLOGY - 2o25 11. M. Black Engineering Building Ames, Iowa 50011 226o 515 294 1423 Jttmary 4; IM FAX 515 294-326 Docket No. 50-116 U.S. Nuclear Regulatory Commission Attn: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738

Subject:

Environmental Report for the Iowa State University UTR-10 Reactor Dear Sir or Madam.

Please find enclosed three copies of the environmental report prepared in preparation for the proposed decommissioning the ISU UTR-10 reactor. This report is being submitted per 10 CFR 51.21 and follows the format set forth in 10 CFR 51.45.

Ifyou have any questions regarding this request, please contact me at (515) 294-0539.

Sincerely, Scott E. WeIxit '

Reactor Manager Enclosure c:(without enclosure)

A.F Rohach, Chm., Reactor Use Committee D.B. Bullen, Facility Director T.S. Michaels, US NRC W.R. DeVries, Chm., Mechanical Engineering Department t

e f

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- v l ENVIRONMENTAL REPORT FOR THE DECOMMISSIONING OF ISU UTR-10 REACTOR INTRODUCTION i

The UTR-10 reactor is located in the Nuclear Engineering Laboratory on the Iowa State University (ISU) campus. The Argonaut type reactor is a light water cooled, graphite reflected reactor fueled with LEU fuel. The UTR-10 is licensed for 10 kW steady-state operation. The reactor began operations in 1959 and produced a total of 7629 kW-hrs of energy during 9541 hours0.11 days <br />2.65 hours <br />0.0158 weeks <br />0.00363 months <br /> of operation.

l The University plans to decommission the UTR-10 after returning the reactor fuel to the US Department of Energy, currently scheduled for April 1999. The DECON area, as delineated in l the Decommissioning Plan (DP), will be released for unrestricted use by the College of l

Engineering. The University has elected to exclude particular equipment and facilities, such as the subcritical lab in Room 101, from complete decontamination, with the provision that such equipment and facilities will be transferred to the State ofIowa Radioactive Materials License.

ACTIVITIES AND TASKS REQUIRED FOR DECON l The reactor fuel is expected to be shipped off-site in early 1999 before decommissioning l activities are initiated. The removal of the fuel is considered to be separate from l decommissioning activities. The DP outlines fifteen activities and tasks to be accomplished in

! the sequence shown below:

Task 1 Mobilization & Preparation

( Task 2 Radiological Containment & Dust Control Plan i Task 3 Demolition & Construction Task 4 Removal of Stairs Task 5 Plug Removal, Prep & Packaging l Task 6 Water Tank Demolition Task 7 Graphite & Core Component Removal Task 8 Bio-Shield Removal Task 9 Wire Saw Cutting Task 10 Block Segregation Task 11 Pit Excavation Task 12 Tank & Sump Equipcaent Removal l Task 13 Miscellaneous Equipment Removal

! Task 14 Temporary Staging Areas l Task 15 Waste Disposal Descriptions and analyses of the above tasks are covered in the UTR-10 DP.

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DESCRIPTION OF ENVIRONMENT AFFECTED The reactor room and rooms adjacent to the reactor room in the Nuclear Engineering Laboratory will be the affected environment. The windows, doors, and walls in this area are defined as the  !

confinement boundary for the UTR-10 reactor. There is no forced ventilation system within the coufinement boundary or within the building. The Nuclear Engineering Laboratory is located on the west part of the main Iowa State University campus. Iowa State University is located in the west pan of Ames, Iowa. Maps that show the relative locations of Ames and ISU can be found in the UTR-10 DP.

ENVIRONMENTAL IMPLICATIONS OF DECON A comprehensive Safety Analysis Repon (SAR) was completed in August 1981. This repon addressed environmental implications of routine and accident conditions related to the reactor.

The corresponding Safety Evaluation Report (SER), NUREG 1016, was issued by the NRC in September 1983. Since the fuel will have been removed prior to the stan of DECON activities, the potential for environmental impacts will be greatly reduced.

In fact, due to the small amount of radioactive materials present, no adverse radiological impact is expected. During the decommissioning, the reactor room and adjacent rooms will be classified as construction / demolition zones for a period of several months and therefore will be unusable l by the university. The estimated collective occupational doses for decommissioning activities 1 are shown in Table 1. ,

l Table 1. Estimated Collective Doses for Decommissioning Activities I Decommissioning Activity Estimated Collective Dose (person-rem)

Site Characterization 0.0*

Systems Removal 0.7 Bio-Shield Removal & Demolition 1.7 Total 2.4

• Actual measurement data from TLDs Radiation exposure to the general public is expected to be zero. This will be accomplished by keeping the public at a safe distance and by eliminating effluent releases during decommissioning. A safe distance will be maintained by not allowing the public within the confinement boundary for the reactor. The existing doors that lead into the facility will be i locked. Keys for those doors will be issued only to those people are qualified to enter.

All liquid waste that is generated during the decommissioning activities will be collected in barrels and disposed ofin accordance with state and federal guidelines. All decommissioning activities will be carried out within the Nuclear Engineering Laboratory's confinement boundary.

Additional containment measures will be taken as necessary to minimize the spread of contamination within the confinement boundary. These measures will include wood framing covered with plastic and low volume water misting. Airborne releases of radioactive materials are not expected. Dust production will be minimized by low volume water mist at points where dust is produced. Descriptions of the above tasks are covered in the UTR-10 DP.

7 .s DECON activities will result in the generation oflow-level radioactive waste. This waste can be categorized as:  ;

• Activated metal components from the reactor internals 4 e Activated and contaminated concrete and other structural material e Radioactive miscellaneous waste .

The estimated disposal volume of radioactive waste is 1200 R' as determined in the UTR-10 DP.

Non-radioactive demolition waste will be disposed oflocally.

Residual radioactivity remaining aRer decommissioning will be at the level of background radiation. Potential exposure to the public aner license terminatN is anticipated to be well below 25 mrem / year.

ALTERNATIVES The non-power reactor decommissioning requirements in 10 CFR 50.82 (bXIXii) and (bXIXiii) state that decommissioning activities should be completed without significant delay unless prevented by factors beyond the licensee's control. This essentially limits the choice for non-power reactors to the DECON alternative.

The DECON alternative for decommissioning the UTR-10 reactor was selected aRer evaluating the three decommissioning alternatives described in the NRC guidance document NUREG-0586.

DECON is the preferred alternative for the following reasons: i e The ISU UTR-10 is a small reactor, rated at 10 kW power level.  :

• The volume of radioactive waste generated from decommissioning activities is estimated to l be small.

• Commercial radioactive disposal facilities are accessible to the project.

• Radioactivity is limited to the activated materials in the reactor containment structure.

Radiological surveys of the reactor environs show that radioactive contamination is limited with elevated levels confined to a very small location (~200 cm2 ) on the reactor floor, e ISU personnel familiar with the reactor are available.

• The University intends to utilize the space for other programs aRer the area is approved for unrestricted release by the NRC.

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