f . I OFI ORNL P 2356 m ' i .. .. . .. . .. . .. 1 1 .. . 11 . . II. ****** 1.1.25 1.4 1.6 : MICROCOPY RESOLUTION TEST CHART NATIONAL QUREAU OF STANDARDS - 1963 11 . r Nice II, Jerant. N.G. & Wicka, C.D. MASTER [ . co ORDL-P-2356 Conf-66/001-20 SEP 2 2 1966 Cowadnici ORNI - AEC - OFFICIAL MANIPULATOR MAINTENANCE PROGRAM AT OAK RIDGE NATIONAL LABORATORY HC. $ 400 MAS? As a result of the techniques and facilities developed at Oak Ridge National Laboratory, it is felt from both the mainten- ance and research viewpoint that a very 88tisfactory manipulator maintenance program has been established at the Laboratory. A specially trained crew of one foreman, ten millwrights, and one electrician has been organized to maintain the 237 installed manipulators. Maintenance work of this volume has required the establishment of a maintenance facility covering 6000 sq. ft. of floor space. It is divided into a cleaning area, contaminated repair area, clean repair area, and a boot fabrication area. Some development activities are accomplished in this facility, but these are generally limited to recurring maintenance problems or special requests from research personre!. Due to the different cell environments to which manipulators are exposed and requirements for cell containment, a handling procedure has been established that requires very close coordina- tion of health Physics and Maintenance personnel. (Figure 1) Manipulators with contact readings as high as 1000 R/Hr, have been removed from hot cells, successfully repaired and returned to service. The special emphasis on containment at ORNL requires that all manipulators be booted. It has been impractical to purchase boots from outside vendors because of tailoring requirements; so, the Laboratory has developed a method of boot fabrication using liquid urethane rubber. Boot changes now represent 50 percent of the overall manipulator maintenance program. Prior to 1961, all manipulator maintenance was performed on an as-needed basis; but with the increasing number of units in service this type of ORNL – AEC - OFFICIAL ORNI - AEC - OFFICIAL RSLEASED FOR ANNOUNCEMENT - - LEGAL NOTICE The report was prepared us an account of Government sponsored work. Neither abe United statos, por ese Commission, por inny person acung on behalf of the Commission: A. Mekes voy mrrunty or representation, expressed or implied, with respect lo the accu- racy, completeneIS, or usefulness of the information contained in this report, or that the use of way information, appuns mus, mulbod, or process disclosed la wis report may not infringu printaly owned rigblo; or B. Assumes may liabilities with respect to the use rif, or for damages resulting from the une of way information, apparitus, melbod, or process disclosed in this report, As used in the above, "person actag on behalf of the Commission" Includes any en- ployee of coolraclor of the Commission, or employee of such contractor, to the extent that gucb employee or contractor of the Commissioa, or employee of such coolrbc.or prepares, disseminates, or provides access to, any information pursuant to his employment or contract wild the Commission, or be employment with such contractor. - IN NUCLEAR SCIENCE ABSTRACTS Page 2 net ::- ORNI - AEC - OFFICIAL :::., maintenance resulted in an excessive number of major overhauls and extended periods of cell downtine. Therefore, in 1961 a computer programmed maintens ce system was initiated; and the results have proven very satisfactory. With this system, each installed unit is checked every two to four weeks depending on its usage. Tape and cable tensions are adjusted, motions checked, and linkages inspected for out-of-tolerance conditions. Prior to programmed maintenance, the average unit was taken to the repair facility twice a year; this frequency has been reduced to an average of one trip per year. Records resulting from programmed maintenance have shown that the annual cost of manipulator repairs will vary from $600 - $1000 per unit, and the annual service calls show that all down time due to manipulator maintenance will vary from five to ten days per year. OPNI - AEC - OFFICIAL vinou wij ORNI - AEC - OFFICIAL .in.:.:: MANIPULATOR MAINTENANCE PROGRAM at OAK RIDGE NATIONAL LABORATORY D. T. Dice R. G. Jenness C. D. Wicker Oak Ridge National Laboratory Total Pages - Total Figures - 9 2 ODNI - AEC - OFFICIAL ORNL - AEC - OFFICIAL ORNI - AEC - OFFICIAL MANIPULATOR MAINTENANCE Page 2 ORNI - AEC - OFFICIAL ORNL - AEC - OFFICIAL - - - - - . . . - - - - - Page 3 ORNL - AEC - OFFICIAL ABSTRACT The volume of master slave manipulator maintenance at Oak Ridge National Laboratory has necessitated the establishment of a repair facility and organization of a specially trained group of craftsmen. Emphasis on cell containment requires the use of manipulator boots and development of precise procedures for ac- complishing the maintenance of 237 installed units. To provide the most economical type of preventive maintenance a very satis- factory computer programmed maintenance system has been established at the Laboratory. ORNL - AEC - OFFICIAL Page 4 ORNL - AEC - OFFICIAL ORNL - AEC - OFFICIAL INTRODUCTION Master slave manipulators wer: developed because a need arose for a tool that could operate in hostile environments behind barracades ur through shielding walls. It was also re- quired that this tool be capable of making all the manipulations that could be performed by the human hand. The resulting maste'. slave manipulators have proven to be a very useful device for research activities particularly in the nuclear energy field. Manipulator type work started at Oak Ridge National Lab- oratory in 1953 with the installation of a Model 4 unit in the Solid State Division hct cells. Since that time the number of manipulators has increased to 237. To provide the necessary maintenance for this number of manipulators the Laboratory has developed a specially trained crew of one foreman, ten millwrights and one electrician. FACILITIES AND EQUIPMENT The manipulator repair facility at ORNZ has approximately 6000 sq. ft. of floor space which is divided into four areas of operation. (Figure 1). Two of these areas are used for contaminated repairs and the other two are used for clean repairs and boot fab- rication. One contamination area contains two glove boxes which are designed to accept the entire slave end of a unit including the through tube. The boxes are in an enclosed room with a carefully controlled air balance system that maintains the boxes at a nego ative pressure with respect to the room. Air is exhausted from boxes to atmosphere through two banks of high-efficiency filters which are instrumented for monitoring the pressure drop. These boxes are equipped with a high-pressure cleaning device that has proven very satisfactory for decontamination purposes, but ORNI - AEC - OFFICIAL ORNI - AEC - OFFICIAL uljisso - * - live u IVILJO-13 V - INTO ORNL-DWG 66-5923 SPRAY BOOTHS MOCK UP CELL LAYOUT AREA BOOT FABRICATION SECTION: BUILCING 2018 - CLEAN AREA- CONTAMINATION AREA --- . CLEAN REPAIR AND ASSEMBLY AREA CONTAMINATED REPAIR AREA AIR LOCK || GLOVE BOXES MANIPULATOR REPAIR FACILITY: BUILDING 3074 figure 1. ORNL - AEC - OFFICIAL ORNL - AEC - OFFICIAL Page 5 ORNL - AEC - OFFICIAL ORNI - AEC - OFFICIAL occas: onally it is necessary to use a clearer which contains a small amount of hydrofluoric acid. It has been desirable to use one box as an alpha box and the second as a beta-gamma to prevent any cross-contamination of manipulators. When it be- comes necessary to disassemble a unit due to excessive internal contamination or worn parts, it is taken to the second contamination area which contains a rebuild area for handling these units. This area has all the required mechanical equipment needed to repair or replace parts during re-assembly of a unit. A dishwasher- type apparatus and an ultrasonic cleaner for ure in cleaning small parts is also located in this area. The third area or clean area of operation is used for checking new manipulators or final checkout of units that save been through the decontamination pro- cess Limited development activities are also carried out in this area. The fourth area of operation is the boot development The average unit weighs approximately 300 lbs, making it necessary to design and fabricate all the handling equipment for the dunl purposes of cell installation or removal and transporta- tion to and from the repair facility. The Laboratory has fabricated two portable dollies of a modified "A" frame design which incor- porates a hydraulic cylinder. The cylinder is located on a series of rollers and tracks which allows movement in any required direction for aligning a unit at the cell wall penetration. The dollies are designed so that they become a part of the unit for transportation purposes. When taken to the repair shop the mani. pulator is placed in a glove box for cleaning or decontaminacion and the dolly is then available for other service. REMOVAL PROCEDURE The procedure developed at ORNL for pulling manipulators requires that the area immediately in front of the cell be roped off as a contamination area; craftsmen dress-out according to - - - - - - - ORNI - AEC - OFFICIAL - ORNI – AEC - OFFICIAL - - - . Page 6 ORNL - AEC - OFFICIAL ORNI - AEC - OFFICIAL Health Physics instruction. (Figure 2). These requirements will vary with each cell depending on the enviro.iment to which the manipulator has been exposed. To maintain containment, an 8 mil. polyethylene pull-sleeve is placed over the unit, taped to the wall ani to the through tube. With constant Health Physics monitoring the manipulator is then slowly withdrawn into the pull- sleeve and after complete removal the sleeve is sealed at two separate areas. The sleeve is then cut between the two seals. This method has been used successfully co remove units from a cell with contact radiation readings as high as 1000 R/Hr. Where localized high radiation is encountered, a lead impregnated vinyl shielding blanket is wrapped around that area of the unit. figurer MANIPULATOR BOOTS The special emphasis on cell containment at ORNL requires that all manipulators be equipped with boots to seal the cell opening for the manipulator. This fact has enlarged the mainten- ance problem in that with booted units fifty to sixty percent of their maintenance lies in replacing worn or damaged boots. Due to tailoring required for boots in many of ORNL hot cell faci- lities, it has been impractical to procure boots from outside vendors. Therefore, in 1961 the Research Services Department instituted a development program to provide a material and a means of producing boots that would meet the needs of the Lab- oratory. This investigation resulted in a spray method of boot fabricatio iquid urethane rubber. © From a maintenance standpoint, the protection afforded a manipulator by the use of boots has prolonged slave-end bearing life and has considerably decreased mechanical failures. To date, however, the decrease in mechanical failures has been partially off-set by the number of boot failures. ORNI - AEC - OFFICIAL ORNL - AEC - OFFICIAL '..- . - 247 .0igjilano. rindu pon - -. * : 2 . Firma - 2 . 1 1 ; 2 w . See : 10. That ...od na 't itt ! . . copy : :1B : .. :.-.. I. + - 1 . . i ***.ammans med # -. --;- . .. G 5 conto. GIM:S ·lado ORNL - AEC - OFFICIAL figure 2 ORNL - AEC - OFFICIAL Page 7 ORNL - AEC - OFFICIAL To reduce the number of manipulator removals for boot changes and since nearly all boot failures occur in the gauntlet area, a two-piece boot is now in use in many hot cells at the Laboratory. This two-piece boot is fabricated so that the lower section, including gauntlet, can be remotely removed and replaced by a manipulator. % A180, with the present activities at ORNL involving transuranium elements and the rigid safety require- ments for handling these materials, a double boot is now being fabricated for 20 manipulators in the Transuranium Processing Plant (TRU). PROGRAMMED MAINTENANCE Until 1961 all manipulator maintenance work was performed on an "as needed" basis. šíachines remained in operation until a failure occurred and the unit was inoperable. Experience had shown that if minor adjustments could be made froin time-to-time the more serious difficulties could be alleviated. To minimize cell down-time and to achieve more efficient manipulator per- formance, a computer programmed maintenance system was introduced. This program includes a two-week to one-month check on each in- stalled inanipulator. Tape and cable tensions are measured and adjusted, all motions are checked for possible malfunctions and linkages are inspected for wear or out-of-tolerance condicions. A preventive maintenance program of this type has proven very satisfactory at the Laboratory and an approximate 30% savings in maintenance costs has been realized. Prior to programmed maintenance the average unit was taken to the manipulator repair facility twice per year; after the programmed maintenance system was established the units now average one trip per year to the maintenance facility. In general, statistics available from the programmed maint- enance activities show that annual costs of manipulator repairs ORNL - AEC - OFFICIAL Page 8 :sir #ti = - ORNI - AEC - OFFICIAL ORNL - AEC - OFFICIAL will vary froti $600 to $1000 per unit. The cell down-time due to manipulator removal and installation will vary from five to ten days per year. It should be noted, however, that the max- imum time required to remove or install a unit is three hours. The five to ten days figure is acquired by using an accumulation of the total time required for each service call. Another inter- esting statistic shown by programmed maintenance 18 that the right hand manipulator requires twice as many repairs as the left hand unit. This may indicate that when designing an in- cell system consideration should be given to a right hand type of operation. A manifold of valves or sampling stations when placed on che left side of cell would simplify the operation for a right handed operator. CONCLUSION As a rüsult of the techniques and facilities described in this paper, it is felt from both the maintenance and research viewpoint that a very satisfactory manipulator maintenance pro- gram has been established at ORNL. This program will be continuing as the number of manipulators are increasing and the demands on the functions are broadening. - - - - - - - : .-- - --. - . ERE ORNI - AEC - OFFICIAL ORNI - AEC - OFFICIAL - - - - . t -: s Page 9 * - - - - - ; - Pins Min.DAY.YAYO - ;:; . . ." . . -- ACKNOWLEDGEMENTS -. --. - -- - - - - The information contained in this article was sponsored by the U. S. Atomic Energy Commission under contract with the Union Carbide Corporation. REFERENCES 1. D. T. Dice and C. D. Wicker, "Urethane Manipulator Gauntlets," ORNL · IM-1326, November 9, 1965, Oak Ridge National Laboratory, Oak Ridge, Tennessee R. G. Jenness, "Two-Piece Manipulator Boot," Proceedings of the 13th Conference on Remote Systems Technology 1965, Oak Ridge National Laboratory, Oak Ridge, Tennessee L- . - - ORNL - AEC - OFFICIAL ! 244744 h alut " X 14 Thai W WW. PN END DATE FILMED 10/21 / 66 -.- .- .* - :: . . : www