In 1977 the Spent Fuel Handling and Packaging Program (SFHPP) was initiated by the Department of Energy to develop and test the capability to satisfactorily encapsulate typical spent fuel assemblies from commercial light-water nuclear power plants and to establish the suitability of one or more surface and near surface concepts for the interim dry storage of the encapsulated spent fuel assemblies. The E-MAD Facility at the Nevada Test Site, which is operated for the Department of Energy by the Advanced Energy Systems Division (AESD) of the Westinghouse Electric Corporation, was chosen as the location for this demonstration because of its extensive existing capabilities for handling highly radioactive components and because of the desirable site characteristics for the proposed storage concepts. This paper describes the remote operations related to the process steps of handling, encapsulating and subsequent dry storage of spent fuel in support of the Demonstration Program

Bahorich, R.J.

Cross, T.E.

Durrill, D.C.

Unterzuber, R.

UNT Digital Library

V • • "" CO /U/£\ £ code? - . 7 4MASTERSPENT LWR FUEL ENCAPSULATION ANDDRY STORAGE DEMONSTRATIONR. 0. BAHORICH, D. C. DURRILL, T. E. CROSS, R. UNTERZUBERPresented at the American Nuclear Society1980 Annual Meeting Held in Las Vegas,Nevada, June 9-12, 1980, Sponsored bythe Remote Systems Technology DivisionWESTINGHOUSE ELECTRIC CORPORATIONADVANCED ENERGY SYSTEMS DIVISIONP. 0. BOX 10864PITTSBURGH, PENNSYLVANIA 15236i t^^^y' iy stale o>— DISCLAIMER .W3TR1311IOM 01- THIS OflCUMENI !8 UKUMITEOABSTRACTIn 1977 the Spent Fuel Handling and Packaging Program (SFHPP) was initiatedby the Department of Energy to develop and test the capability to satisfactorilyencapsulate typical spent fuel assemblies from commercial light-water nuclearpower plants and to establish the suitability of one or more surface and nearsurface concepts for the interim dry storage of the encapsulated spent fuelassemblies. The E-MAD Facility at the Nevada Test Site, which is operated forthe Department of Energy by the Advanced Energy Systems Division (AESD) of theWestinghouse Electric Corporation, was chosen as the location for this demon-stration because of its extensive existing capabilities for handling highlyradioactive components and because of the desirable site characteristics forthe proposed storage concepts. This paper describes the remote operationsrelated to the process steps of handling, encapsulating and subsequent drystorage of spent fuel in support of the Demonstration Program.Log Number 00278SPENT LWR FUEL ENCAPSULATION ANDDRY STORAGE DEMONSTRATIONR. 0. Bahorich, D. C. Durrill, T. E. Cross, R. UnterzuberWestinghouse Electric CorporationAdvanced Energy Systems DivisionINTRODUCTIONDemonstration of encapsulation and interim storage of spent light-waterreactor fuel in dry configurations is underway at the E-MAD facility in Nevada(see Figure 1). This facility is located in the southwest corner of theNevada Test Site and is operated for the Department of Energy (DOE) by theAdvanced Energy Systems Division of the Westinghouse Electric Corporation.Initial use of the E-MAD facility for remote handling and encapsulation ofspent reactor fuel assemblies was in support of the DOE Spent Fuel Handlingand Packaging Program (SFHPP) Demonstration. The objective of this demon-stration was to develop and test the capability to satisfactorily encapsulatetypical spent fuel assemblies from commercial nuclear power plants and toestablish the suitability of one or more surface and near surface storageconcepts for the interim dry storage of the encapsulated spent fuel assemblies.This paper describes the remote operations related to the process steps ofhandling, encapsulating and subsequent dry storage of spent fuel in supportof the Demonstration Program.DESCRIPTION OF THE E-MAD FACILITYThe E-MAD facility was chosen as the location for this demonstrationbecause of its extensive existing capabilities for handling highly radioactivecomponents ahd because of the desirable site characteristics for the proposedstorage concepts. The major features of the facility are shown in Figure 2.The E-M/D facility contains a number of hot cells of varying size, each having1zG5COUJo<ZLUI-2UJ0035H *£ V*u> UJ gS S |UJ UJ 2D S «^ K 5r>: s «j/*w CL4%?'",.. •' \ \ \+JCD03cuOCMto(11CLBacuOJTRANSFER PITLAG STORAGE PITFUEL TEMPERATURETEST CONTROL CONSOLEFigure 2. E-MAD First Floor Plan Showing Locations ofDemonstration Work Stations and Equipmentthe capability of handling highly radioactive objects from shielded worklocations using a variety of remote handling devices. The main cell or HotBay is a high bay area constructed of heavily reinforced concrete shield wallswith numerous lead glass viewing windows. The bay is 43 meters long, 20 meterswide, and 23 meters high. Two large shield doors exist in the Hot Bay throughwhich movement of equipment into and out of the Hot Bay is accomplished. Themain door to the bay is located at the north end and allows truck or rail caraccess into the bay. A second shield door exists at the south end of the bayfor access into the Hot Hold and Transfer Tunnel.Tho Hot Bay is equipped with a number of remote handling systems tosupport remote operations within the Hot Bay. These include:• A travelling overhead bridge crane with a 36.3 te (40-ton)capacity main hook and a 9.1 te (10-ton) capacity auxiliary hook.• A Wall Mounted Handling System, consisting of two identicalarticulated travelling boom assemblies with manipulators,installed on the east wall of the Hot Bay.• Pairs of heavy duty master/slave manipulators at most of thefirst floor viewing windows.These systems can be seen in Figure 3 which shows a spent fuel canisterpackage being inserted into a sealed storage cask inside the Hot Bay.Figure 3. View of E-MAD Hot Bay Showing Major Remote HandlingSystems Being Used to Install a Spent Fuel CanisterPackage into a Sealed Storage CaskThe modifications made to E-MAD, together with associated equipment andcomponents developed in support of the SFHPP Demonstration, permit the receipt,visual inspection, and encapsulation of either PWR or BWR spent fuel assemblies.Capability is also provided for the leak testing of completed canisters, lagstorage of canisters within E-MAD (24 storage locations), and the emplacementof canisters into interim storage configurations outside E-MAD. The designsof the process equipment and storage configuration are described in Reference 1.The SFHPP Demonstration involved the remote handling and encapsulationof three spent PWR fuel assemblies; two encapsulated assemblies were placedin a near surface drywell storage configuration shown in Figure 4 and thethird was placed in a surface Sealed Storage Cask storage configurationshown in Figure 5. In addition, thirteen spent PWR fuel assemblieshave been received and encapsulated for use in the spent fuel geologicstorage test in the Climax granite stock at the Nevada Test Site.PROCESS STEPSThe development of a remote handling system along with the design,fabrication, and assembly of supporting hardware and test equipment wereperformed to support the major process steps reauired for handling, encapsu-lation, and interim storage of spent fuel assemblies at the E-MAD facility.The designs of the process steps and equipment and the system componentswere strongly influenced by the need for compatibility with the E-MAD facility,the desire to utilize existing E-MAD features and equipment to the maximumextent practicable, and the desire to provide a high degree of safety and ahigh probability of success without the need for costly and time-consuminginterim modifications. Design considerations related to high volume productionhad low priority.COVERSOILCANISTERHUPS-SHIELD PLUGSUPPORT PINDRVWELL LINERGROUTFigure 4. SFHPP Demonstration Drywell Storage ConfigurationCOVER- SOILSHIELD PLUGSUPPORT PINLIFTING TRUNNIONLINERCONCRETECANISTERSEISMIC RESTRAINTBRACKETSCONCRETESUPPORT PAD•??'tf-:~iFigure 5. SFHPP Demonstration Sealed Storage Cask ConfigurationInitial operations in the sequence of events are performed "hands-on"and include receipt and unloading of the shipping cask from the trailer followedby positioning of the shipping cask in the work stand. All subsequent operationsare performed remotely. The major process steps are described in the followingsections. The entire sequence of events, including hands-on operations, occursin one continuous 8-hour period.Preparation of Spent Fuel Shipping Cask for UnloadingThe spent fuel shipping cask, transporter trailer, and truck tractorare washed down at another Nevada Test Site location to remove road dirt priorto arrival of the vehicle at E-MAD. The shipping cask is visually inspectedfor damage, and then the vehicle is backed into the Hot Bay. Shipping caskvendor instructions are followed to prepare the transporter and cask for caskoff-loading. Using the cask lifting yoke and the E-MAD overhead crane, thecask is upended, lifted off the transporter, and placed in the cask workplatform. The cask is shown being moved from transporter to the work platformin Figure 6. Hands-on cask operations include installation of the cask ventline, venting of the cask internal pressure through the Hot Bay ventilationsystem stack, removal of the cask closure lid holddown bolts, and attachmentof the lid lifting fixture.Unloading of Fuel Assembly from Shipping CasK and Placement into Canisterin Weld PitAfter the cask unloading preparations have been completed, subsequentoperations are performed remotely. The next step is to use the overheadcrane to remove the shipping cask closure lid and place it on its stand toallow access to the fuel assembly as shown in Figure 7. The overhead crane***Figure 6. Shipping Cask Being Moved from the Transporterto the Hot Bay Cask Work Platform\ ::1 :• 11i i •i I,Figure 7. Shipping Cask Closure Lid Being Remotely Removedis then used to pick up the PWR fuel assembly handling tool from its standshown in Figure 8 and insert the tool into the shipping cask to engage thefuel assembly.After engaging the fuel assembly with the handling tool, the overheadcrane is used to lift the fuel assembly out of the shipping cask, and thenthe assembly is visually examined along the full length of each side by aTV camera held by one of the Wall Mounted Handling System manipulators shownin Figure 9. Video tape records are made for future reference. After thisexamination, the fuel assembly is moved to trie weld pit and placed into anempty canister that had been previously placed in the weld pit as shown inFigure 10.Installation and Melding of Canister Closure LidFollowing installation of the fuel assembly into the canister, theclosure lid is picked up, aligned over the canister, and lowered into thetop of the canister as shown in Figure 11. The closure lid torque tool isused to thread the closure lid into the canister upper body. With the closurelid fully threaded in, a Wall Mounted Handling System manipulator is used toinstall the seal welding machine on the closure lid in penetration forwelding.Sealing of the canister is accomplished by fusion welding of a small lip,machined as part, of the closure lid, to the top surface of the canister body.This fusion weld is accomplished by a fully contained welding machine, shownFigure 8. PWR Fuel Assembly Handling Tool inIts Storage Stand in Hot Bay13r.7 II I 1 (IC,g:1 1 I!XFigure 9. PWR Fuel Assembly Suspended from the OverheadCrane While Being Examined by a TV Camera14Figure 10. PWR Fuel Assembly Suspended from OverheadCrane Being Lowered into Canister in Weld Pit15Figure 11. Canister Closure Lid Being Threaded into Canister16in Figure 12, designed specifically for remote operation on a canister.Figure 13 shows a photograph of a completed seal weld taken through one ofthe E-MAD periscopes.Canister Evacuation and Helium BackfillFollowing seal welding, the closure lid cap is removed and the evacuation/backfill hose is connected to the closure lid as shown in Figures 14 and 15.The air in the canister is evacuated and the canister is backfilled with heliumto a pressure of approximately one atmosphere. After helium filling is complete,the evacuation/backfill hose is removed and the fitting on the closure lid iscapped and torqued.Leak Check of Complete CanisterAfter the canister has been filled with helium and the closure lid fittingtorqued, the Wall Mounted Handling System is used to place the vacuum chamberhood over the weld pit, as shown in Figure 15, for the helium leak check operation.Installation of Canister Package Shield PlugAfter the vacuum chamber hood is removed, the overhead crane is used topick up a shield plug and place it on the canister as shown in Figure 17. Akeyway in the shield plug extension mates with the support key on the canisterbody and the shield plug vertical alignment pipe rests on the canister closurelid to automatically align the canister support pins with the flat-bottomedholes in the canister body. A support pin torque tool held by the Wall MountedHandling System is used to thread the support pins in to mate with the holesin the canister body, thus completing the shield plug attachment operation.17Figure 12. Canister Closure Lid Being Seal Welded18"'*Figure 13. Periscope View of Completed Seal WeldFigure 14. Removing Closure Lid Cap for Evacuation and Backf i l lFigure 15. Installation of Evacuation/Backfill HoseFigure 16. Vacuum Chamber Being Installed inPreparation for Canister Leak Check-I-Figure 17. Shield Plug Being Lowered over Canister inPreparation for Attachment to Canister23Surface Contamination Check of Completed CanisterAfter the shield plug is connected to the canister, the overhead craneis used to move the canister package to the survey pit located in the south-west corner of the Hot Bay in front of the pass-through drawer and manipu-lator stations at viewing windows as shown in Figure 18. The 11-foot deepsurvey pit is a remote work station which provides accessibility to a sealedcanister package suspended from the overhead crane to obtain survey swipesto evaluate canister surface contaimination. A pit is required to permitthe canister to be lowered sufficiently so that the top of the canister canbe reached by the manipulator. During the survey operation, the canister ismoved vertically by the overhead crane while the manipulator operator takesswipes of the canister at a number of locations aj shown in Figure 19. Theswipes are then placed in the pass-through drawer for transfer to the operatinggallery for counting.Transfer of Canister Package to Drywell StorageAt this point the canister package can be inserted into the lag storagepit for temporary storage or inserted into the transfer pit in preparation fortransfer to a drywell outside the Hot Bay (at this time the canister packagecould also be installed in a sealed storage cask, which is described in thefollowing section). The transfer pit is located between the rails near thecenter of the Hot Bay as shown in Figure 2 and is designed to accommodate acanister package in a configuration essentially identical to the drywell config-uration shown in Figure 4. The location and configuration of the transfer pitpermit the canister package to be picked up by the transfer vehicle for movementto an outside drywell as shown in Figures 20 and 21,241 1! »Figure 18. Completed Canister Package Suspendedfrom Overhead Crane over Survey Pit25Figure 19. Canister Package Being Remotely Swiped at Survey Pit for Contamination Checkfr-r a n s f e r V e h i ' J p R e i t v i i ; ! ) v i P i t in Hot Bayp, — ^roCOFigure 21. Transfer Vehicle After Completion of Canister Package Transfer to DrywellTransfer of Canister Package to Sealed Storage Cask StorageIf, instead of transferring a canister package to a drywell, it is desiredto place the package into a Sealed Storage Cask (SSC), a different mode oftransfer is used. The SSC is transportable by truck to permit loading acanister package into the SSC in the E-MAD Hot Bay. Figure 3 shows acanister package being lowered into a SSC. This figure shows closed circuitTV cameras held by the two Wall Mounted Handling System units. These TVcameras are used by the crane operator to guide the canister package intothe SSC. The truck subsequently moves the SSC to the storage site outsidethe E-MAD building where the SSC is lifted off the truck and placed on afoundation pad by means of a large mobile crane as shown in Figure 22.SUMMARYThe equipment and modifications made to E-MAD to support the SFHPPDemonstration are generic in the sense that they can be used (or easilymodified) to fulfill encapsulation requirements for any experimental programinvolving the use of encapsulated spent fuel assemblies or any radioactivewaste form.Presently, E-MAD offers encapsulation and testing equipment, experience,baseline data, and qualified computer models which are available to supportother technology development programs. To further meet the future needs ofnuclear waste isolation programs, the following additions to E-MAD are beinginstalled.29Figure 22. Sealed Storage Cask Containing Canister Package Being Liftedby Mobile Crane for Final Emplacement.1. A fuel assembly calorimeter to accurately determine thethermal heat output of a spent fuel assembly. This hard-ware will provide for the remote handling and insertionof the fuel assembly into the calorimeter and subsequentremote operation of the test.2. A canister cutting tool to remotely gain access to anencapsulated fuel assembly for post-demonstration examina- |•Ition. iREFERENCES1. R. J. Steffen, et al., "Equipment Designs for the Spent LWR Fuel DryStorage Demonstration," Trans. Am. Nucl. Soc, This Meeting (1980).ACKNOWLEDGEMENTThe work described in this paper was performed for the UnitedStates Department of Energy, Nevada Operations Office underContract No. DE-AC08-76NV00597.COPYRIGHTBy acceptance of this article, the publisher and/or recipientacknowledges the U. S. Government's right to retain a non-exclusive, royality-free license in and to any copyrightcoveri ng the arti cle.32

Spent LWR fuel encapsulation and dry storage demonstration

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Spent LWR fuel encapsulation and dry storage demonstration

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