Regulatory Guide 1.104

Overhead Crane Handling Systems for Nuclear Power Plants

ML13038A096
Person / Time
Issue date:	02/28/1976
From:	Office of Nuclear Regulatory Research, NRC/OSD
To:
References
RG-1.104
Download: ML13038A096 (11)

U.S. NUCLEAR REGULATORY COMMISSIONREGULATORY GUIDEOFFICE OF STANDARDS DEVELOPMENTREGULATORY GUIDE 1.104OVERHEAD CRANE HANDLING SYSTEMSFOR NUCLEAR POWER PLANTSA. INTRODUCTIONFebruary 1976General Design Criterion 1, "Quality Standards andRecords," of Appendix A, "General Design Criteria forNuclear Power Plants," to 10 CFR Part 50, "Licensingof Production and Utilization Facilities," requires thatstructures, systems, and components important to safetybe designed, fabricated, erected, and tested to qualitystandards commensurate with the importance of thesafety function to be performed. General Design Cri-terion 2, "Design Bases for Protection Against NaturalPhenomena," requires that structures, systems, and com-ponents important to safety be designed to withstandthe effects of natural phenomena such as earthquakes.General Design Criterion 5, "Sharing of Structures,Systems, and Components," prohibits the sharing ofstructures, systems, and components important to safetyamong nuclear power units unless it can be shown thatsuch sharing will not significantly impair their ability toperform their safety functions. In addition, GeneralDesign Criterion 61, "Fuel Storage and Handling andRadioactivity Control," requires, in part, that be1lstorage and handling systems be designed to ensureadequate safety under normal accident condition. n-Regulatory Guide 1.13, "Spent Fuel Sto:a-eFacility Design Basis," describes methods acceptableto the NRC staff for complying with the Comi-mssion'sregulations with regard to the construction of spentfuel storage facilities and 1 handling systems.Appendix B, "Quality, Assurance Criteria for Nu-clear Power Plantsaind FueVlReprocessing Plants," to 10CFR Part 50 in .part, that measures be estab-lished to ensure oontrol-fdesign, materials, fabrication,special processes, installation, testing, and operation ofstructures, systems, and components important tosafety, including crane handling systems. Section. 50.55a,"Codes and Standards," of 10 CFR Part 50 requires thatdesign, fabrication, installation, testing, or inspection ofcertain specified systems or components be in accor-dance with generally recognized codes and standards.This guide describes methods acceptable to the NRCstaff for complying with the Commissiofis regulationswith regard to the design, fabrication, and testing ofoverhead crane systems used for react,16Te fueling andspent fuel handling operations. This guide aplies to allnuclear power plants for whi te, applicants elect toprovide a single-failure-proof oveiadi crane handlingsystem.B. DISCUSIONThe of critical loads can be accom-plished by "addirngsaety features to the handling equip-menti by adding special features to the structures andareas over "which the critical load is carried, or a combin-ation of the two, thus enabling these areas to withstandthue ;effcýts of a load drop in case the handling equipment1,fas. This guide covers critical load handling equipmentfor those plants where reliance for safe handling of cri-tical loads will be placed on the overhead crane system"by making it single failure proof.Overhead crane handling systems are often used forhandling critical items at nuclear power plants. Thehandling of critical loads such as a spent fuel cask raisesthe possibility of damage to the safety-related systems,structures, and equipment under and adjacent to thepath on which it is transported should the handlingsystem suffer a breakdown or malfunction during thishandling period. Definitions of critical items or criticalloads should be submitted in the PSAR.Design CriteriaTo provide a consistent basis for selecting equip-ment and components for the handling of critical loads,a list of codes, standards, and recommended practicesUSNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. NuclearRegulatory Commission, Washington, D.C. 20565. Attention: Docketing andRegulatory Guides are issued to describe and make available to the public Service Section.methods acceptable to the NRC staff of implementing specific parts of theCommissions regulations. to delineate techniques used by the staff in evalu. The guides are issued in the following ten broad divisions.sting specific problems or postulated accidents, or to provide guidance to applicants. Regulatory Guides are not substitutes for regulations. and compliance 1 Power Reactors 6. Productswith them is not required. Methods and solutions different from those set out in 2. Research and Test Reactors 7. Transportationthe guides will be acceptable if they provide a basis for the findings requisite to 3. Fuels and Materials Facilities 8. Occupational Healththe issuance or continuance 1 a permit or license by the Commission. 4. Environmental and Siting 9. Antitrust ReviewComments and suggestions for i,, povenrenr.s ,n these guides are encouraged 5 Materials and Plant Protection 10 Generalat all times, and guides will be revised as appropriate. to accommodate com-ments and to reflect new information or experience However comments on Copies of published guides may be obtained by written request indicating thethis guide, if received within about two months after its issuance, will be par- divisions desired to the U.S Nuclear Regulatory Commission. Washington. D.C.tIcularly useful ,n evaluating the need for an early revision 20555. Attention: Director. Office of Standards Developmen generally available to industry is appended to this guide.The applicable requirements of these standards and re-commendations should be used to the maximum extentpractical to obtain quality construction. Where dif-ferences or conflicts in interpretation exist between thecodes, standards, or recommendations, use of the moststringent requirement is recommended. However, specialfeatures should be added to prevent and control or stopinadvertent operation and malfunction of the load-supporting and -moving components of the handlingsystem.When an overhead crane handling system will beused during the plant construction phase prior to itsintended service in the operating plant, separate perfor-mance specifications are needed to reflect the dutycycles and loading requirements for each service. At theend of the construction period, changes to the cranesystem may be required to reflect the specifications forthe permanent operating plant condition. For example,if the specifications for the size of the hoist drive motordiffer sufficiently for the two applications, the motorand the affected control equipment would have to bereplaced or changed for the operating plant phase. Fea-tures and functions needed for the cranes during theplant construction period are not considered in thisguide except where the use of the crane may influenceits design and operation for the permanent plant opera-tion.Overhead cranes may be operating at the time whenan earthquake occurs. Therefore. the cranes should bedesigned to retain control of and hold the load, and thebridge and trolley should be designed to remain in placeon their respective runways with their wheels preventedfrom leaving the tracks during, a seismic event. If aseismic event comparable to a safe shutdown earthquake(SSE) occurs, the bridge should remain immobile on therunway, and the trolley with load should remain im-mobile on the crane girders.Since all the crane loading cycles will produce cyclicstress, it may be necessary to investigate the potentialfor failure of the metal due to fatigue. When a crane willbe used for the construction period, it will experienceadditional cyclic loading, and these loads should beadded to the expected cyclic loading for the permanentplant operation for the fatigue evaluation.Materials and FabricationBridge and trolley structures are generally fabricatedby welding structural shapes together. Problems havebeen experienced with weld joints between rolled struc-tural members. Specifically, subsurface lamellar tearinghas occurred at the weld joints during fabrication andthe load-bearing capacity of the joint has thus been re-duced. Radiography or ultrasonic inspection, as appro-priate, of all load-bearing weld joints would help toensure the absence of lamellar tearing in the base metaland the soundness of the weld metal; Other problemswith welding of low-alloy steels can occur if the basemetal temperature is not properly controlled duringwelding and the postweld heat treatment. RegulatoryGuide 1.50, "Control of Preheat Temperature for Weld-ing of Low-Alloy Steel," identifies this potential prob-lem and indicates an acceptable procedure for obtainingsound welds in low-alloy steels.Cranes are generally fabricated from structuralshapes and plate rolled from mild steel or low-alloy steel.Some of these steel parts exceed 1/2 inch in thickness andmay have brittle-fracture tendencies during some of theintended operating temperatures, so that testing of thematerial toughness becomes necessary. Specifically, thenil-ductility transition temperature (NDTT) should bedetermined.Safety FeaturesGeneral. Numerous applications have been reviewedby the staff, and the need for inclusion of certain safetyfeatures and the magnitudes of specific operationallimits to provide adequate safety have been determined.It is. important to prevent the release of radio-activity in case of failure, inadvertent operation, mal-function, or loss of load, and it may be necessary toinclude special features and provisions to precludesystem incidents that would result in release of radio-activity.A crane that has been immobilized because of mal-function or failure of controls or components whileholding a critical load should be able to set the loaddown while repairs or adjustments are made. This can beaccomplished by inclusion of features that will permitmanual operation of the hoisting system and the bridgeand trolley transfer mechanisms by means of ancillary,auxiliary, or emergency devices.A crane handling system includes all the structural,mechanical, and electrical components that are neededto lift and transfer a load from one location to another.Primary or principal load-bearing components, equip-ment, and subsystems such as the driving equipment,drum, rope reeving system, control systems, and brakingmeans should receive special attention.All auxiliary hoisting systems of the main cranehandling system that are employed to lift or assist inhandling critical loads should be provided with the samesafety features as the rest of the main crane handlingsystem.Hoisting Machinery. Proper support of the ropedrums is necessary to ensure that they would be retainedand prevented from falling or disengaging from their1.104-2 braking and control system in case of a shaft or bearingfailure. Two mechanical holding brakes in the hoistingsystem (raising and lowering) that are automatically ac-tivated when electric power is off or when mechanicallytripped by overspeed devices or overload devices in thehoisting system will help ensure that a critical load willbe safely held or controlled in case of failure in theindividual load-bearing parts of the hoisting machinery.Each holding brake should have more than full-loadstopping capacity but should not have'excessive capacitythat could cause damage through sudden stopping of thehoisting machinery. A brake capacity of 125% to 150%of the breakdown torque developed by the motor at thepoint of brake application has been determined to beacceptable.Manual operation of the hoisting brakes may benecessary during an emergency condition, and provisionfor this should be included in the design conditions.Adequate heat dissipation from the brake should be en-sured so that damage does not occur if the loweringvelocity is permitted to increase excessively. Featuresshould be included in the manual control of the brake tolimit the lowering speed. A limiting velocity of 3.5 fpmhas been determined to be acceptable for trouble-freeoperation.Component parts of the vertical hoisting mechanismare important. Specifically, the rope and reeving systemdeserves special consideration during design of the sys-tem. The selection of the hoisting rope which is a "run-ning rope" should include consideration of size, con-struction, lay, and means of lubrication to provide forthe efficient working of the strands and individual wires.The load-carrying rope will suffer'accelerated wear if itrubs excessively on the sides of the grooves in the drumand sheaves due to improper alignment or large fleetangles between the grooves. The load-carrying rope willfurthermore suffer shock loading if it is partly held byfriction on the groove wall and then suddenly released toenter the bottom of the groove. The rope can beprotected by the selection of conservative fleet angles.Ropes may also suffer damage due to excessive straindeveloped if the cable construction and the pitchdiameter of the sheaves are not properly selected.Fatigue stress in ropes can be minimized when the pitchdiameter of the sheaves are selected large enough toproduce only nominal stress levels. The pitch diameterof the sheaves should be larger for ropes moving at thehighest velocity near the drum and can be smaller forsheaves used as equalizers where the rope is stationary.Equalizers for stretch and load on the rope reevingsystem may be of either beam or sheave type. A dualrope reeving system with individual attaching points andmeans bor balancing or distributing the load between thetwo operating rope reeving systems will permit eitherrope system to hold the critical load and maintain bal-ance in case of failure of the other rope system.Selection of hoisting speed is influenced by suchitems as reaction time for corrective action for the hoist-ing movement and the potential behavior of a failedrope. To prevent or limit damaging effects that may re-sult from dangerous rope spinoff in case of a rope break,the hoisting speed should be limited. A 5 fpm hoistingspeed limit is an acceptable limit. The rope travelingspeed at the drum is higher than at other points in thereeving system, and the potential for damage due to ropeflailing and interference with other parts of the systemshould be considered. Conservative industry practicelimits the rope line speed to 50 fpm at the drum as aconservative approach.Power transmission gear trains are often supportedby fabricated weldments of structural parts. The properalignment of shafts and gears depends on the adequacyof bearings and their supports to maintain correct align-ment of all components. The proper functioning .of thehoisting machinery during load handling can best be en-sured by providing adequate support strength and properalignment of the individual component parts and thewelds or bolting that binds them together.Bridge and Trolley. Failure of the bridge and trolleytravel to stop when power is shut off could result inuncontrolled incidents. This would be prevented if bothbridge and trolley drives are provided with control andholding braking systems which will be automaticallyapplied when the power is shut off or if an overspeed oroverload condition occurs because of malfunction orfailure in the drive system. Sufficient braking capacitywould be needed to overcome torque developed by thedrive motor and the power necessary to decelerate thebridge or trolley with the attached load to a completestop. A holding or control capacity of 100 percent ofthe maximum torque developed at the point of brakeapplication would be an acceptable capacity for eachbraking system. Drag-type brakes are subject to excessivewear, and the need for frequent service and repair tendsto make this type of brake less reliable; they thereforeshould not be used to control movements of the bridgeand trolley.The travel speed of the trolley and bridge will in-fluence the operation of the crane as well as the equip-ment design and selection. Numerous crane applicationshave been studied and it has been concluded that thetravel speed for nuclear power plant application shouldbe conservatively selected. Trolley and bridge speedlimits of 30 fpm and 40 fpm, respectively, have beendetermined to be acceptable.Drivers and Controls. Of the basic types of electricdrive motors available for crane operation, the series-wound a.c. or d.c. motors or shunt-wound d.c. motorsare readily adaptable to various control systems, andeither of these types would be acceptable. Compound-wound motors should not be used because of difficultyin control of the breakdown torque. The horsepower1.104-3 rating of the driving motor should be matched with thecalculated requirement that considers the design loadand acceleration to the design hoisting speed. Over-powering of the hoisting equipment would impose addi-tional strain on the machinery and load-carrying devicesby increasing the hoisting acceleration rate. A motor rat-ing limited to 110% of the design rating would provideadequate power without loss of flexibility and would beacceptable.Normally, a crane system is equipped with mechani-cal and electrical limiting devices to shut off power todriving motors when the crane hook, trolley, and bridgeapproach the end of travel or when other parts of thecrane system would be damaged if power was not shutoff. It is prudent to include safety devices in the controlsystem for the crane, in addition to the limiting devices,for the purpose of ensuring that the controls will returnto or maintain a safe holding position in case of malfunc-tion, inadvertent operation or failure, or overspeed andovertorque conditions. Overpower and overspeed con-ditions should be considered an operating hazard as theymay increase the hazard of malfunction or inadvertentoperation. It is essential that the controls be capable ofstopping the hoisting movement within amounts ofmovement that damage would not occur. A 3-inch maxi-mum hoisting movement would be an acceptable stop-ping distance.Operational TestsOperational tests of crane systems should be per-formed to verify the proper functioning of limit switchesand safety devices and the ability to perform as de-signed. However, special arrangements may have to bemade to test overload and overspeed sensing devices.Existing Handling SystemsIt may be necessary to determine the extent towhich an existing handling system and the areas in whichthe load is transported may require that the cranehandling system be single failure proof. Therefore, adetailed inspection may be necessary to determine thecondition of each crane prior to its continued use and todefine the portion of, the system that may needalteration, addition, or replacement in order to ensure itsability to perform acceptable handling of critical loads.Quality AssuranceAlthough crane handling systems for critical loadsare not required for the direct operation of a nuclearpower plant, the nature of their function makes it neces-sary to ensure that the desired quality level is attained. Aquality assurance program should be established to theextent necessary to include the recommendations of thisguide for the design, fabrication, installation, testing,and operation of crane handling systems for safehandling of critical loads.C. REGULATORY POSITIONWhen an applicant chooses to provide safe handlingof critical loads by making the overhead crane handlingsystem single-failure proof rather than by adding specialfeatures to the structures and areas over which the criti-cal load is carried, the system should be designed so thata single failure will not result in loss of the capability ofthe handling system to perform its safety functions.Overhead crane handling systems used for handlingcritical loads (following construction) such as loads dur-ing reactor refueling and spent fuel handling should bedesigned, fabricated, installed, inspected, tested, andoperated in accordance with the following:1. Performance Specification and Design Criteriaa. Separate performance specifications thatare required to develop design criteria should be pre-pared for a permanent crane that is to be used for con-struction prior to use for plant operation. The allowabledesign stress limits should be identical for both cases,and the sum total of simultaneously applied loads shouldnot result in stress levels causing permanent deformationother than localized strain concentration in any part ofthe handling system.b. The operating environment, including max-imum and minimum pressure, temperature, humidity,and emergency corrosive or hazardous conditions,should be specified for the crane and lifting fixtures.(1) Closed box sections of the crane struc-ture should be vented to avoid collapse during contain-ment pressurization. Drainage should be provided toavoid standing water in the crane structure.(2) Minimum operating temperaturesshould be specified in order to reduce the possibility ofbrittle fracture of the ferritic load-carrying members ofthe crane. Materials for structural members essential tostructural integrity should be impact tested unless ex-empted by the provisions of paragraph AM-218 of theASME Code,Section VIII, Division 2. However, the"minimum design temperature" as used therein shouldbe defined as 60'F below the minimum operating tem-perature. Either drop weight test per ASTM E-208 orCharpy tests per ASTM A-370 may be used for impacttesting. The minimum drop weight test requirementshould be nil-ductility transition temperature (NDTT)not less than 60'F below the minimum operating tem-perature. Minimum Charpy V-notch impact test require-ments should be those given in Table AM 211.1 of theASME Code.Section VIII, Division 2, which should bemet at a temperature 60°F below the minimum operat-ing temperature. Alternative methods of fracture anal-ysis that achieve an equivalent margin of safety againstfracture may be used if they include toughness measure-ments on each heat of steel used in structural members1.104-4 essential to structural integrity. In addition, tfle tractureanalysis that provides the basis for setting minimumoperating temperatures should include consideration ofstress levels; quality control; the mechanical checking,testing, and preventive maintenance program; and thetemperatures at which the design rated load test is runrelative to operating temperature.(3) As an alternative to the recommenda-tions of regulatory position C. 1 .b.2, the crane and liftingfixtures may be subjected to a cold proof test as des-cribed in regulatory position C.4.d.(4) Cranes and lifting fixtures made oflow-alloy steel such as ASTM A514 should be subjectedto the cold proof test described in regulatory positionC.4.d.c. The crane should be classified as SeismicCategory I and should be capable of retaining the max-imum design load during a safe shutdown earthquake(SSE), although the crane may not be operable after theseismic event. The bridge and trolley should be providedwith means for preventing them from leaving their run-ways with or without the design load during operationor under any seismic excursions. The design rated loadplus operational and seismically induced pendulum andswinging load effects on the crane should be consideredin the design of the trolley, andthey should be added tothe trolley weight for the design of the bridge.d. All weld joints for load-bearing structuresincluding those susceptible to lamellar tearing should beinspected, including nondestructive examination forsoundness of the base metal and weld metal.e. A fatigue analysis should be considered forthe critical load-bearing structures and components ofthe crane handling system. The cumulative fatigue usagefactors should reflect effects of the cyclic loading fromboth the construction and operating periods.f. Preheat and postheat treat~nent (stress re-lief) temperatures for all weldments should be specifiedin the weld procedure. For low-alloy steel, the recom-mendations of Regulatory Guide 1.50, "Control of Pre-heat Temperature for Welding- of Low-Alloy Steels."should be applied.2. Safety Featuresa. The automatic controls, and limiting de-vices should be designed so that, when disorders due toinadvertent operation, component malfunction, or dis-arrangement of subsystem control functions occur singlyor in combination during the load handling and failurehas not occurred in either subsystems or components,these disorders will not prevent the handling systemfrom being maintained at a safe neutral holding position.b. Auxiliary systems, dual components, or an-cillary systems should be provided so that. in case ofsubsystem or component failure, ,the load will beretained and held in a stable or immobile safe position.c. Means should be provided for using the de-vices required in repairing, adjusting, or replacing thefailed component(s) or subsystem(s) when failure of anactive component or subsystem has occurred and theload is supported and retained in the safe (temporary)position with the handling system immobile. As an alter-native to repairing the crane in place, means may beprovided for safely moving the immobilized handlingsystem with load to a safe laydown area that has beendesigned to accept the load while the repairs are beingmade.d. The design of the crane and its operatingarea should include provisions that will not impair thesafe operation of the reactor or release radioactivitywhen corrective repairs, replacements, and adjustmentsare being made to place the crane handling system backinto service after component failure(s).3. Equipment Selectiona. Dual load attaching points (redundant de-sign) should be provided as part of the load block assem-bly which is designed so that each attaching point will beable to support a static load of 3W (W is weight of thedesign rated load) without permanent deformation ofany part of the load block assembly other than localizedstrain concentration in areas for which additional mate-rial has been provided ror wear.b. Lifting devices that are attached to theload block such as lifting beams, yokes, ladle or trunniontype hooks, slings, toggles, and clevises should be of re-dundant design with dual or auxiliary device or combina-tions thereof. Each device should be designed to supporta static load of 3W without permanent deformation.c. The vertical hoisting (raising and lowering)mechanism which uses rope and consists of uppersheaves (head block), lower sheaves (load block), andrope reeving system, should provide for redundantly de-signed dual hoisting means. Maximum hoisting speedshould be no greater than 5 fpm.d. The head and load blocks should be de-signed to maintain a vertical load balance about the cen-ter of lift from load block through head block and havea reeving system of dual design. The loadblock shouldmaintain alignment and a position of stability witheither system being able to support 3W within the break-ing strength of the rope and maintain load stability andvertical aligrnment from center of head block through allhoisting components through the center of gravity of theload.1.104-5 e. Design of the rope reeving systei(s) shouldbe dual with each system providing separately the loadbalance on the head and load blocks through configura-tion of ropes and rope equalizer(s). Selection of thehoisting rope or running rope should include considera-tion of the size, construction, lay, and means or type oflubrication to maintain efficient working of the indivi-dual wire strands when each section of rope passes overthe individual sheaves during the hoisting operation. Theeffects of impact loadings, acceleration, and emergencystops should be included in selection of rope and reevingsystems. The wire rope should be 6 x 37 NWRC (ironwire rope core) or comparable classification. The leadline stress to the drum during hoisting (dynamic) at themaximum design speed with the design rated load shouldnot exceed 20% of the manufacturer's published ratedstrength- Line speed during hoisting (raising or lowering)should not exceed 50 fpm.f. The maximum fleet angle from drum tolead sheave in the load block should not exceed 3-%degrees at any one point during hoisting and should haveonly one 1 80-degree reverse bend for each rope leavingthe drum and reversing on the first or lead sheave on theload block with no other reverse bends other than at theequalizer if a sheave equalizer is used. The fleet anglesbetween individual sheaves for rope should not exceed1-1/2 degrees. Equalizers may be of the beam or sheavetype or combinations thereof. For the recommended 6 x37 IWRC classification wire pitch diameter ofthe lead sheave should be 30-times the rope diameter foithe 180-degree reverse bend, 26 times the rope diameterfor running sheaves and drum, with 13 times the ropediameter for equalizers. The pitch diameter is measuredfrom the center of the rope on the drum or sheavegroove through the center of the drum or sheave to thecenter of the rope on the opposite side. The dual reevingsystem may be a single rope from each end of a drumterminating at one of the blocks or equalizer with pro-visions for equalizing'beam type load and rope stretch,with each rope designed for the total load, or a 2-ropesystem may be used from each drum or separate drumsusing a sheave equalizer or beam equalizer, or any othercombination which provides two separate and completereeving systems.g. The portions of the vertical hoisting systemcomponents, which include the head block, rope reevingsystem, load block, and dual load-attaching device,should each be designed to sustain a test load of 200% ofthe design rated load. Each reeving system and each one-of the load-attaching devices should be assembled withapproximately a 6-inch clearance between head and loadblocks and should support 200% of the design rated loadwithout permanent deformation other than localizedstrain concentration or localized degradation of the com-ponents. A 200% static-type load test should be per-formed for each reeving system and a load-attachingpoint at the manufacturer's plant. Measurements of thegeometric configuration of the attaching points shouldbe made before and after the test and should be fol-lowed by a nondestructive examination that should con-sist of combinations of magnetic particle, ultrasonic,radiograph, and dye penetrant examinations to verifythe soundness of fabrication and ensure the integrity ofthis portion of the hoisting system. The results of exami-nations should be documented and recorded for thehoisting system for each overhead crane.h. Means should be provided to sense suchitems as electric current, temperature, overspeed, over-loading, and overtravel. Controls should be provided toabsorb the kinetic. energy of the rotating machinery and,stop the hoisting movement within a maximum of 3inches of vertical travel through a combination of elec-trical power controls and mechanical braking systemsand torque controls if one rope or one of the dual reev-ing system should fail or if overloading or an overspeedcondition should occur.i. The control systems should be designed asa combination of electrical and mechanical systems andmay include such items as contactors, relays, resistors,and thyristors in combination with mechanical, devicesand mechanical braking systems. The electric controlsshould be selected to provide a maximum breakdowntorque limit of 175% of the required rating for a.c.motors or d.c. motors (series or shunt wound) used forthe hoisting drive motor(s). Compound wound dcc.motors should not be used. The control system(s) pro-vided should include consideration of the hoisting(raising and lowering) of all loads, including the maxi-mum design rated load, and the effects of the inertia ofthe rotating hoisting machinery such as motor armature,shafting and coupling, gear reducer, and drum.j. The mechanical and structural componentsof the complete hoisting system- should have the re-quired strength to resist failure if the hoisting systemshould "two block"1I or if "load hangup"2 should occurduring hoisting. The designer should provide meanswithin the reeving system located on the head or on theload block combinations to absorb or control the kineticenergy of rotating machinery prior to the incident oftwo .blocking oruload hangup. The location of mnechan-ical holding brakes and their controls should providepositive, reliable, and capable means to stop and holdthe hoisting drum(s) for the conditions described in thedesign specification and regulatory positions 1 and 2.This should include the maximum torque of the driving1"Two blocking" is the act of continued hoisting in which theload block and head block assemblies are brought into physicalcontact, thereby preventing further movement of the loadblock and creating shock loads to rope and reeving system.2"Load hangup" is the act in which the load block and/or load isstopped during hoisting by entanglement with fixed objects,thereby overloading the hoisting system.1.104-6 motor cannot be shut off.k. The load hoisting drum on the trolleyshould be provided with structural and mechanicalsafety devices to prevent the drum from dropping,disengaging from its holding brake system, or rotating, ifthe drum or any portion of its shaft or bearings shouldfail or fracture.1. To preclude ekcessive *breakdown torque,the horsepower rating of the electric motor drive forhoisting should not exceed 110% of the calculated de-sign horsepower required to hoist the design rated loadat the maximum design hoist speed.m. The minimum hoisting braking systemshould include one power control braking system (notmechanical or drag brake type) and two mechanicalholding brakes. The holding brakes should be activatedwhen power is off and should be automatically mechani-cally tripped on overspeed to the full holding position ifmalfunction occurs in the electrical brake controls. Eachholding brake should be designed to 125%-1150% of themaximum developed torque at point of application (lo-cation of the brake in the mechanical drive). The mini-mum design requirements for braking systems that willbe operable for emergency lowering after a single brakefailure should be two holding brakes for stopping andcontrolling drum rotation. Provisions should be made formanual operation of the holding brakes. Emergencybrakes or holding brakes which are to be used formanual lowering should be capable of operation withfull load and at full travel and provide adequate heatdissipation. Design for manual brake operation duringemergency lowering should include features to limit thelowering speed to less than 3.5 fpmrLn. The dynamic and static alignment of allhoisting machinery components including gearing, shaft-ing, couplings, and bearings should be maintainedthroughout the range of loads to be lifted, with all com-ponents positioned and anchored on the trolley ma-chinery platform.o. Increment drives for hoisting may be pro-vided by stepless controls or inching motor drive. Plug-ging3 should not be permitted. Controls to prevent plug-ging should be included in the electrical circuits and thecontrol system. Floating point4 in the electrical powersystem when required for bridge or trolley movementshould be provided only for the lowest operating speeds.p. To avoid the possibility of overtorquewithin the control system, the horsepower rating of the3Plugging is the momentary application of full line power to thedrive motor for the purpose of promoting a limited movement.4That point in the lowest range of movement control at whichpower is on, brakes are off, and motors are not energized.motion of the overnead brsage crane shouui nut exceea110% of the calculated horsepower requirement at maxi-mum speed with design rated load attached. Incrementalor fractional inch movements, when required, should beprovided by such items as variable speed or inchingmotor drives. Control and holding brakes should each berated at 100% of maximum drive torque at the point ofapplication. If two mechanical brakes, one for controland one for holding, are provided, they should be ad-justed with one brake in each system for both the trolleyand bridge leading the other and should be activated byrelease or shutoff of power. The brakes should also bemechanically tripped to the "on" or "holding" positionin the event of a malfunction in the power supply or anoverspeed condition. Provisions should be made formanual operation of the brakes. The holding brake shouldbe designed so that it cannot be used as a foot-operatedslowdown brake. Drag brakes should not be used. Oppo-site wheels on bridge or trolley that support bridge ortrolley on their runways should be matched and haveidentical diameters. Trolley and bridge speed should belimited. A maximum speed of 30 fpm for the trolley and40 fpm for the bridge is recommended.q. The complete operating control system andprovisions for emergency controls for the overhead cranehandling system should be located in the main cab onthe bridge. Additional cabs located on trolley or liftingdevices should have complete control systems similar tothe bridge cab. Manual controls for hoisting and trolleymovement may be provided on the trolley. Manual con-trols for the bridge may be located on the bridge. Re-mote control or pendant control for any of these mo-tions should be identical to those provided on the bridgecab, control panel. Provisions and locations should beprovided in the design of the control systems for devicesfor emergency control or operations. Limiting devices,mechanical and electrical, should be provided to indicateand control or prevent overtravel and overspeed ofhoist (raising or lowering) and for both trolley andbridge travel movements. Buffers for bridge and trolleytravel should be included.r. Safety devices such as limit type switchesprovided for malfunction, inadvertent operation, or fail-ure should be in addition to and separate from the limit-ing means or devices provided for operation in the afore-mentioned. These would include buffers, bumpers, anddevices or means provided for control of malfunction(s).s. The operating requirements for all travelmovements (vertical and horizontal movements or rota-tion, singly or in combination) incorporated in the de-sign for permanent plant cranes should be clearly de-frned in the operating manual for hoisting and for trolleyand bridge travel. The designer should establish the max-imum working load (MWL). The MWL should not be lessthan 85% of the design rated load (DRL) capacity for1.104-7

-the n.w crane at time, of operation. The redundancy indesign, design factors, selection of components, andbalance of auxiliary-ancillary and dual items in the de-sign and manufacture will provide or dictate the maxi-mum working load for the critical load handling cranesystems. The MWL should not exceed the DRL for theOverhead Crane Handling System.t. When the permanent plant crane is to beused for construction anid the operating requirements forconstruction are not identical to those required for pre-manent plant service, the construction operating require-ments should be completely defined separately. Thecrane should be designed structurally and mechanicallyfor the construction loads, plant service loads, and theirfunctional performance requirements. At the end of theconstruction period, the crane handling system shouldbe adjusted for the performance requirements of thenuclear power plant service. The design requ.-ments forconversion or adjustment may include the replacementof such items as motor drives, blocks, and reeving sys-tem. After construction use, the crane should be thor-oughly inspected by nondestructive examination andperformance tested. If allowable design stress limits areto be exceeded during the construction phase, addedinspection supplementing that of regulatory positionC.l.d should be considered. If the load and performancerequirements are different for construction and plantservice periods, the crane should be tested for bothphases. Its integrity should be verified. by designer andmanufacturer with load testing to 125% of the designrated load required for the operating pl~t before it isused as permanent plant equipment.u. Installation instructions should be providedby the manufacturer. These should include a full expla-nation of the crane handling system, its controls, and thelimitations for the system and should cover the require-ments for installation, testing, and preparations for oper-ation.4. Mechanical Check, Testing, and PreventiveMaintenancea. A complete mechanical check of all thecrane systems as installed should be made to verify themethod of installation and to prepare the crane fortesting.During and after installation of the cranethe proper assembly of electrical and structural com-ponents should be verified. The integrity of all control,operating, and safety systems should be verified as tosatisfaction of installation and design requirements,The crane designer and crane manufacturershould provide a manual of information and proceduresfor uise in checking, testing, and operating the crane. Themanual should also describe a preventive maintenanceprogram based on the approved test results and informa-tion obtained during the testing; it should include suchitems as servicing, repair and replacement requirements.visual examinations, inspections, checking, measure-ments, problem diagnosis, nondestructive examination,crane performance testing, and special instructions.Information concerning proof testing oncomponents and subsystems as required and performedat the manufacturer's plant to verify the ability ofcomponents or subsystems to perform should be avail-able for the checking and testing performed at the placeof installation of the crane system.b. The crane system should be prepared forthe static test of 125% of the design rated load. The testsshould include all positions of hoisting, lowering, andtrolley and bridge travel with the 125% rated load andother positions as recommended by the designer andmanufacturer. After satisfactory completion of the125% static test and adjustments required as a result ofthe test, the crane handling system should be given fullperformance tests with 100% of the design rated load forall speeds and motions for which the system is designed.This should include verifying all limiting and safety con-trol devices. The crane handling system with the designrated load should demonstrate its ability to lower andmove the load by manual operation and with the use ofemergency operating controls and devices that have beendesigned into the handling system.The complete hoisting machinery shouldbe allowed to "two block" during the hoisting test (loadblock limit and safety devices are bypassed). This test,conducted at slow speed without load, should provideassurance of the integrity of the design, the equipment,the controls, and the overload protection devices. Thetest should demonstrate that the maximum torque thatcan be developed by the driving system, including theinertia of the rotating parts at the overtorque condition,will be absorbed or controlled prior to two-blocking.The complete hoisting machinery should be tested forability to sustain a load hangup condition by a test inwhich the load block attaching points are secured to afixed anchor or excessive load. The drum should be cap-able of one full revolution before starting the hoistingtest.c. The preventive maintenance program rec-ommended by the designer and manufacturer-4hkuldalso prescribe and establish the MWL for which the cranewill be used. The maximum working load should beplainly marked on each side of the crane for each hoist-ing unit. It is recommended that the critical loadhandling cranes should be continuously maintained atDRL capacity.d. The cold proof test provided for in regula-tory positions C.l b.3 and 4 should consist of a periodic1.104-8 dumm% load test as follows: Metal temperature of thestructural members, essential to the structural integri,ýof the crane handling system should be at or below theminimum operating temperature. The correspondingd*mmy load should be equal to 1.25 times the max-imum working load (MWL). If it is not feasible toý,-.hive the minimum operating temperature during thetest, the dummy load should be increased beyond thedesign rated load 1.5 percent per degree F temperaturedifference. ,Test frequency should be approximately 40months or less; however, crane handling systems that areused less frequently than once every 40 months may begiven a cold proof test prior to each use. The cold prooftest should be followed by a nondestructive examinationof critical areas for cracks.5. Quality Assurancea. To the extent necessary, applicable pro-curement documents should require the crane manufac-turer to provide a quality assurance program consistentwith the pertinent provisions of Appendix B, "QualityAssurance Criteria for Nuclear Power Plants and FuelReprocessing Plants," to 10 CFR Part 50.b. The program should also address each ofthe recommendations in regulatory positions C.1, C.2,C.3, and C.4.D. IMPLEMENTATIONThe purpose of this section is to provide informa-tion to applicants and licensees regarding the NRC staff'splans for using this regulatory guide.I. Except in those cases in which the applicantproposes an alternative method for complying with spec-ified portions of the Commission's regulations, this guidewill be used in the evaluation of design, fabrication, as-and use of crane systems for critical loadhandling ordered after September 1, 1976.2. For crane handling systems ordered prior toSeptember 1, 1976:a. Regulatory positions C.1, C.2. C.3, and C4will be used in evaluating crane handling systems thathave been ordered but are not yet assembled.b. All regulatory positions except C.I.f: C.3.c,f, and q will be used in evaluating crane handling systemsthat have been assembled or may have been used forhandling heavy loads during plant construction. Regula-tory positions C.l.f; C.3.c, f, and q will be used by theNRC staff to determine the extent of changes or modifi-cations necessary.c. All regulatory positions except C. I.f; C.2.a,b, c, and d; C.3.a, b, c, e, f, g. j. n, o, p, q, r. and t will beused in evaluating crane handling systems that will be orare being used to handle heavy loads that are defined ascritical. Regulatory positions C.l.f; C.2.a, b. c, and d;C.3.a, b, c, e, f, g, j, n, o, p, q, r, and t will be used bythe NRC staff to determine the extent of changes ormodifications necessary to meet the intent of the regula-tory positions.At1.104-9 APPENDIXENGINEERING, MANUFACTURING, AND OPERATING STANDARDS,PRACTICES, AND REFERENCESAISE Association of Iron and Steel Engineers (Std.No. 6)General items for overhead cranes andspecifically- for drums, reeving systems,blocks, controls, and electrical, mechani-cal, and structural components.Copies may be obtained from the Asso-ciation at 3 Gateway Center, Pittsburgh,Pennsylvania 15222.AISC American Institute of Steel Construction,Manual of Steel Construction.Runway bridge design loadings for impactand structural supports.Copies may be obtained from theInstitute at 101 Park Avenue, New York,New York 10017.ASME American Society of Mechanical EngineersReferences for testing, materials, andmechanical components.Copies may be obtained from the Societyat United Engineering Center, 345 East47th Street, New York, New York10017.ASTM American Society for Testing and MaterialsTesting and selection of materials.Copies may be obtained from the Societyat 1916 Race Street, Philadelphia, Penn-sylvania 19103.ANSI American National Standards Institute (A.10,B3, B6, B15, B29, B30, and N45 series)N series of ANSI standards for qualitycontrol. ANSI consensus standards fordesign, manufacturing, and safety.Copies may be obtained from the Insti-tute at 1430 Broadway, New York, NewYork 10018.IEEE Institute of Electrical and Electronics Engi-neersElectrical power and control systems.Copies may be obtained from the Insti-tute at United Engineering Center, 345East 47th Street, New .York, New York10017.AWS American Welding Society (DI,1. 72- 73/74SAESociety of Automotive Engineers, "Stan-dards and Recommended Practices"Recommendations and practices for wirerope, shafting, lubrication, fasteners,materials selection, and load stability.Copies may be obtained from the Societyat 400 Commonwealth Drive; Warrendale,Pennsylvania 15096.CMAA Crane Manufacturers Association of America(CM-AA 70)Guide for preparing functional and per-formance specification and componentselection.Copies may be obtained from the Asso-ciation at 1326 Freeport Road, Pitts-burgh, Pennsylvania 15238.NEMA National Electrical Manufacturers Asso-ciationElectrical motor, control, and componentselections.Copies may be obtained from the Asso-ciation at 155 East 44th Street, NewYork, New York 10017.WRTB Wire Rope Technical Board and their manu-facturing members for selection of rope,reeving system, and reeving efficiencies.Copies may be obtained from the Boardat 1625 1st Street, NW., Washington,D.C. 20006.Mill Materials Handling Institute and their mem-ber associations such as American GearManufacturing Association for gears andgear reducers, Antifriction Bearing Manu-facturers Association for bearing selec-tion, etc.Copies may be obtained from the Insti-tute at 1326 Freeport Road, Pittsburgh,Pennsylvania 15238.WRC Welding Research Council, "Control of SteelConstruction to Avoid Brittle Fracture."Copies may be obtained from the Councilat United Engineering Center. 345 East47th Street, New York, New York10017.WRC Welding Research Council, Bulletin #168,"Lamellar Tearing."Copies may be obtained from the Councilat United Engineering Center, 345 East47th Street, New York, New York10017.Regulatory Guide 1.50, "Control of Preheat Tempera-ture for Welding of Low-Alloy Steel."revisions)Fabrication requirements and standardsfor crane structure and weldments.Copies may be obtained from the Societyat 2501 NW 7th Street, Miami, Florida.33125.Edison Electrical InstituteElectrical Systems.Copies may be obtained from the Insti-tute at 90 Park Avenue, New York, NewYork 10016.EEl1.104-10 UNITED STATESNUCLEAR REGULATORY COMMISSIONWASHINGTON, 0. C. 20555OFFICIAL BUSINESSPENALTY FOR PRIVATE USE, $300POSTAGE AND FEES PAIDUNITED STATES NUCt EARREGULATORY COMMISSION