Regulatory Guide 5.42
| ML003740009 | |
| Person / Time | |
|---|---|
| Issue date: | 01/31/1975 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-5.42 | |
| Download: ML003740009 (7) | |
January 1975 U.S. ATOMIC ENERGY COMMISSION
REGULATORY
DIRECTORATE OF REGULATORY STANDARDS
GUIDE
REGULATORY GUIDE 5.42 DESIGN CONSIDERATIONS FOR MINIMIZING
RESIDUAL HOLDUP OF SPECIAL NUCLEAR MATERIAL
IN EQUIPMENT FOR DRY PROCESS OPERATIONS
A. INTRODUCTION
dry process operations.1 The design features noted will facilitate physical inventory measurements and reduce Paragraph (b) of Section 70.22, "Contents of Appli material balance uncertainties. They are not expected to cations," of 10 CFR Part 70, "Special Nuclear Material," interfere excessively with process operations. In particu requires, among other things, that each application for a lar, this guide is applicable to (1) gas handling, (2) glove license to possess at any one time more than one box operations, (3) calcining, (4) dry solids transfer, effective kilogram of special nuclear material (SNM) (5) dry blending and classification, (6) packed bed con
"containa full description of the applicant's program for versions, and (7) comminution.
control of and accounting for SNM that will be in his possession under license, including procedures for con
B. DISCUSSION
trolling SNhi during its processing or use in the facility and procedures by which process losses are determined. 1. Background Section 70.51, "Material Balance, Inventory, and Records Requirements," indicates that certain licensees Past experience and current observation of process must conduct their nuclear material physical inventories operations used in various systems indicate that the in compliance with specific requirements. publication of general guidelines for equipment design The control of and accounting for SNM can be made could assist in achieving the degree of material control more effective by reducing residual holdup in process and accounting needed for satisfactory protection of equipment following draindown and cleanout. Such a SNM. Sizable amounts of SNM accumulate as deposits reduction would lessen the severity of the problems during material processing or draindown. For certain associated with determining the residual holdup com process steps, modes of operation, and types of material, ponent of a physical inventory and would reduce the the quantity of the accumulated deposit may reach a uncertainty component contributed by residual holdup. steady state that fluctuates around some characteristic The purpose of this guide is to call the attention of amount. In other instances, a deposit may continue to individuals who participate in equipment design and accumulate as the process continues to operate and may layout and in measurement control to the utility and not become apparent until draindown or cleanout. In significance of reducing residual holdup. This guide, either case, the quantity of SNM in residual holdup therefore, is intended for plant managers, designers, following draindown often is difficult to determine with operators, material control personnel, and others at the sufficient precision and accuracy to meet material decision-making level who include safeguards as an integral part of their professional activities. lRegulatory Guide 5.8 addresses drying and fluidized-bed This guide describes design features acceptable to the operations for purposes of minimizing residual holdup of SNM.
Regulatory staff for minimizing the residual holdup of Regulatory Guide 5.25 addresses residual holdup problems SNM after draindown or cleanout of equipment used in unique to aequipment used for wet proem operations.
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7. Trnportatlon
3. Fuels and Materials Facilities S. Occupational elth fublishad guides will be nevised periodically, as appropriate, to accommodate 4. Environmewntl andSiting 9. Antitrust Review commnts anid to nrefict new information or experienca. S. Matariale and PlamtProtection 1
0. Generl
unaccounted for (MUF) and limits of error of MUF b. Glovebox Operations (LEMUF) requirements. Appropriate design could in.
crease the effectiveness of draindown and assist in Gloveboxes are used principally for handling reducing residual holdup and the consequent need for materials containing uranium-233 or plutonium.
determining the retained SNM. Good design also should improve the capability for any needed cleanout follow c. Calcining ing draindown.
Minimizing the quantity of material retained in Calcining is applied to dried solids that have been equipment after draindown generally enhances the effec produced in a precipitation step. For example, plu tiveness of a material protection program in the follow tonium oxalate is calcined to plutonium oxide. The ing ways:
oxide product from the calciner may be subjected to comminution and/or blending before it becomes feed for a. Quality of Physical Inventories the fabrication of fuel. Some equipment can be used to perform both drying and calcining simultaneously. Cer Reducing the quantity of residual holdup that is tain types of scrap or waste may be calcined as part of not amenable to measurement improves the quality of a the recyling or recovery of its contained SNM.
physical inventory. 2 The extent to which the measure ment of the residual holdup contributes to the quality of d. Dry Solids Transfer a physical inventory depends on the amount of holdup and the uncertainty of the measurement method. Dry solids are transferred in a number of fuel conversion or fabrication steps. For example, dry am b. Susceptibility and Accessibility of SNM monium diuranate (ADU) powder formed during the drying of the filter cake from an ADU precipitation If the quantity of residual holdup remaining after process is transferred to a calcining furnace for conver draindown and/or cleanout of equipment is reduced, less sion to uranium dioxide. Similarly, dried mixed SNM is accessible and susceptible to theft or diversion plutonium-uranium oxides formed by coprecipitation during the sampling, identification, and evaluation neces are transferred to the next process step. SNM oxide sary to complete a physical inventory. Lessening the powders are transferred to blenders and to fuel pelletiz effort necessary to remove and/or evaluate residual ing equipment.
holdup reduces the amount of time SNM is accessible, the number of people who need access to it, and the e. Dry Blending and Particle Classification opportunity for unauthorized individuals to gain access to SNM during a physical inventory. Blending and classifying are commonly utilized in various chemical conversion and fuel fabrication pro
2. Unit Operations cesses. Examples include the ammonium diuranate or fluid-bed processes for uranium conversion; the con This guide deals with the reduction of residual SNM version of mixed uranium-plutonium nitrates to mixed holdup during a physical inventory in seven process uranium-plutonium oxides; and the fabrication of spheri operations common to dry chemical processing. These cal particles by spheroidizing and particle coating.
operations are described in the following paragraphs. Dry particulate materials may be blended to produce a uniform mixture of two or more materials having different chemical compositions, particle sizes, a. Gas Handling shapes, surface areas, or other properties.
Classification can be used to produce a controlled Gas-handling operations considered here include particle size distribution or shape for materials to be handling of (1) process gases and (2) carrier gases that blended or for materials that have been blended just may contain suspended SNM particles. The transfer of prior to fabrication.
UF 6 from shipping containers to process vessels is the Blending and classifying may be performed as most common example of the handling of gaseous SNM separate or combined operations.
in a fuel conversion facility. Offgases from activities such as drying, calcination, pneumatic solids transfer, and f. Packed Bed Chemical Conversions fluidized-bed reactions contain SNM in particulate form;
the use of filters, cyclones, and scrubbers to remove Packed bed conversions can be used for converting these particulates from the gas streams should, be a solid uranium compound to a metal or to another solid considered. compound by a controlled exothermic batch reduction process. For example, this type of operation is used for
2 Regulatory Guide 5.13 addresses the subject of conducting the reduction of uranium tetrafluoride to uranium metal physical inventories of nuclear material. with magnesium or calcium meta
l. Compounds of other
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ductwork and filters. Material can also be inadvertently metals may be added to effect a coreduction that yields spilled into inaccessible locations within the calciner an alloy product. Packed bed operations may also be during operation. The fact that the calcined powder used for the reaction of uranium dioxide with carbon or usually has a high bulk density helps to reduce dusting in graphite to produce uranium carbides. handling.
Direct heating in calciners using a heated gas stream g. Comminution can cause dust particles to become entrained in the gas stream. Indirect heating and direct radiant heating, on Comminution is applied to dried or calcined the other hand, do not normally contribute to holdup.
oxides in order to obtain a powder suitable for fabrica Cylindrical rotating-retort calciners are particularly tion into desired fuel shapes. It also may be applied to desirable for high-throughput, low-holdup operation.
dried cake or to solid scrap (which is being prepared for These calciners, which may be operated continuously, recycling) from a fabrication process.
have the advantages of minimum physical handling of The product of comminution is a fine, free-flowing product and great potential for automation. However, powder with a fairly uniform particle size distribution.
the presence of lifting bars or flight carriages in these The comminution equipment is selected so as to control calciners makes them more difficult to drain down or particle size and surface area of the powder and to clean out for a physical inventory of SNM.
obtain the desired pelletizing and sintering properties.
A batch or semicontinuous operation with trays of Ball mills or rod mills may be used to combine material traveling through an indirectly heated muffle blending with a comminution step.
type calciner has comparatively little holdup, unless the trays are accidentally tipped and the contents spilled
3. Holdup in Gas Handling into the calciner as a result of mechanical malfunction of the tray conveyer systems. This problem can be greatly The holdup problems in equipment for handling gases reduced by the use of covered trays.
fall into the following two general categories:
6. Holdup in Dry Solids Transfer a. Those problems related to the storage and transfer of UF 6 , including the prevention of condensation of Dry powders usually are moved from one process step UF6 in transfer lines by heating, the removal of as much to another by manual, mechanical, or pneumatic means.
gas as possible from the containers by heating and The manual method involves loading a container at the purging, and the accurate measurement of the residual
"heel" in the container. discharge point of equipment for one unit process and moving it by hand to the charging position of the equipment of the next unit process. This technique is b. Those problems related to SNM particulates en generally employed when relatively small quantities of trained in gaseous waste streams, including the deposi material are involved. When properly designed, the tion and accumulation of particulates in ducts, filters, containers used to manually transfer dry solids can be cyclones, and scrubbers.
cleanly emptied except for the small amount of material that clings to the inner surface. This residual material
4. Holdup in Gloveboxes can easily be removed by brushing, vacuuming, or dissolution.
Holdup problems in gloveboxes are related to the Mechanical conveyors have broad application in the type of operations and to the degree of leak-tightness of chemical industry, but are not generally used for transfer the process equipment installed within the glovebox. of material containing SNM. Screw and belt conveyors Equipment that is totally and reliably enclosed and is have been used in some operations for moving large essentially automatic in normal operation contributes quantities of ADU powders. Holdup problems with negligible holdup to gloveboxes. Problems of holdup mechanical conveyors generally arise as a result of arise during maintenance or other nonroutine operating material adhering to the surfaces of screws, idlers, periods when process containments are breached. bearings, and belts. Because the screw cannot sweep the Some operations, such as those in which dry solids interior of the transfer tube completely, significant are loaded into and discharged from equipment units, residual material may remain held up in a screw may inherently permit the escape of SNM to the glovebox conveyor. In all mechanical conveyors, dusting can be a environment. Examples of this type of operation are problem.
comminution, blending, and agglomeration where quan Pneumatic conveyors constitute a relatively simple tities of fine powder can escape and accumulate on way to move large quantities of dry solids. In this glovebox internal surfaces and all equipment surfaces. operation, solid particles suspended in air are transferred by the bulk movement of the ai
r. Holdup problems are
5. Holdup in Calcining fewer than with mechanical conveyors since the transfer lines can be kept smooth and free of obstructions. Even Holdup occurs in calcining when powder sticks to though dusting constitutes a problem with pneumatic rough surfaces or is trapped in crevices. The powder may conveyors, the quantity of material remaining after become entrained in gas streams and be deposited in
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draindown is normally small and cleanout can be completely enclosed and sealed, dusting can result in a achieved by sending brushes through the lines or by significant holdup of material.
flushing with cleaning solutions. Mechanical vibrators that are used to classify spheri cal particles are easily cleaned and usually have no significant holdup problems.
7. Holdup in Dry Blending and Classifying
8. Holdup in Packed Bed Conversion Operations Several factors contribute to holdup in blending and classifying equipment. One problem arises when dry "the holdup problem that normally occurs with particulate material of irregular shape and size collects packed bed conversion operations is caused by the SNM
and becomes packed in lines and in internal recesses of that is unreacted or occluded and remains in the slag.
equipment. This is most likely to occur if fine particles This holdup material may be accounted for by non are present. Irregularly shaped particles may become destructive analysis (NDA) or by being recovered in trapped in screens. Spherical particles generally flow normal recycle or scrap-recovery operations.
freely and drain readily from equipment. Ultrafine Occasionally, the refractory lining between the powder must be handled carefully to reduce dusting. packed bed and the steel containment shell for uranium Mechanical batch-type blenders with internal agi metal reduction is porous or thin, permitting molten tators contribute to significant material holdup since any uranium to contact the shell. This results in a "blowout"
material that collects around the mechanical agitator and and the release of uranium metal outside the contain drive mechanism is difficult to remove. Unless sealed ment shell. Spills of this sort can result in significant covers are provided, material can be dispersed as holdup of SNM in auxiliary equipment.
airborne fines. Some ceramic particles from the carbide conversion Holdup problems are minimal in batch-type blenders process adhere to or react with.the walls of the graphite with smooth internal surfaces, no internal moving parts crucible. This holdup material, which cannot be re and designs that permit charging and discharging by covered by a simple draindown or cleanout operation, gravity. The simple V-cone blender with a full-diameter contributes to MUF until the crucible is evaluated or cover is an example of this type of blender; it is most processed for recovery of SNM, but its contribution is difficult to prevent holdup in the gasket area. Dust normally small.
accumulations on the surfaces of a V-cone blender can easily be removed with a brush oi wipe. 9. Holdup in Comminution Equipment Pneumatic batch-type blenders are equipped with feed and recirculation piping that extends the surface Nearly all flow of material through: comminution area to which material can adhere. This piping system equipment is by gravity. Equipment is normally capable makes pneumatic blenders particularly difficult to clean. of being drained down with a minimum of holdup.
Although these blenders may be designed to discharge Holdup of SNM in comminution is most likely to occur by gravity, a holdup problem can result if a line becomes in the form of airborne particles that leak from plugged or packed with material that is not detected equipment or that escape during transfer and handling upon draindown. and collect in ventilation ducts, filters, or on the surfaces Some operations combine commilnution with blend of equipment and gloveboxes.
ing to reduce the size of particles while performing a If gyratory or jaw crushers are used in the comminu mixing operation. Ball or rod mills may be used for this, .tion operation, some holdup may occur on the corru but the large surface areas of such mills may result in gated surfaces of the jaw faces.
significant material holdup after emptying. The design of When SNM consists of hard friable ceramic tinter this equipment makes it especially difficult to clean. cake or fused particles, equipment such as rotary Blending may also be done by splitting and recom hammer mills may be used for comminution. The binig of controlled quantities of material. This gravity irregular surfaces of breaker plates, rotating mechanical flow operation may include mechanical agitation of the discs and hammers, and screen bars in this equipment flowing stream with an impeller or gas jet. The principal contribute to holdup and make draindown and cleanout source of material holdup in splitters is the accumulation difficult.
or caking of material on ledges and in recesses in the equipment Plugging is a problem in the extensive piping
C. REGULATORY POSITION
or tubing used with multiple splitters. For this reason, mechanica vibrators are used to keep material flowing in To facilitate the measurement and/or recovery of lines. residual special nuclear material held up in process The sieves, .ýreens, and air classifiers used to classify equipment and to improve the accuracy grd reliability dry particles cuutnbute to some holdup of SNM. of a physical inventory, the amount of residual SNM
Particles that are tiapped and held up in screen openings held up in equipment should be minimized.. The design are difficult to remove and may require some mechanical of equipment used to carry out physical or chemical cleaning. Material is held up in the piping used with air changes on special nuclear material by dry process classifiers. Unless screens or sieves and air classifiers are operations, including gas handling, glovebox activities,
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calcining, dry solids transfer, dry blending and classi 2. Internal Design fying, packed bed conversion, and comminution, should incorporate features that minimize residual holdup. a. Equipment should have a minimum of internal Some appropriate equipment design features and components upon which process material can collect.
characteristics whose use is acceptable to the Regulatory staff for this purpose are described in the following b. Sensing devices such as thermocouples or other paragraphs. These features should be implemented to the detectors should be installed in a manner that minimizes extent practicable. Implementation also should be con the amount of solid material that can be retained on sistent with other quality assurance, health, and nuclear their surfaces.
safety codes and standards that may be applicable.
c. Permanently mounted process equipment internals
1. General Design that cannot be removed for cleaning should be designed and installed in a manner that minimizes holdup in the a. Inside surfaces of equipment and gloveboxes equipment during draindown and permits cleanout if should be free of crevices, protrusions, and other necessary.
irregularities that could entrap material.
d. The inner surfaces of ducts in which deposition of b. Inside surfaces of equipment and gloveboxes that particulates can occur should be smooth and free of contact SNM should be selected, coated, polished, or recesses or other irregularities. Vessels and transfer lines machined to prevent or resist the adherence of powders in which condensation of vapors can occur should be or other dry particles. heated and/or insulated.
c. Where possible, the lower portions of vessels such e. Provision should be made for heating and purging as blenders and storage bins should be of conical shape UF 6 cylinders and transfer lines to permit maximum and fitted with bottom outlets to facilitate material removal of the gas.
draindown and cleanout.
d. Overlapping metal surfaces in contact with process f. Pneumatic conveyors should be fabricated without material should be avoided except where sealed by internal obstructions to the flow of air and suspended welding; internal welds should be ground flush with solids. Charging and emptying ports should be designed inner surfaces. Possible exceptions are gasketed openings to minimize dusting and holdup of material at these such as inspection and cleanout doors or ports. points.
e. The internal angles, comers, and recesses of g. Trays that are used to transport material through gloveboxes and equipment should be designed and batch or semicontinuous muffle-type calciners should be constructed to permit complete draindown or cleanout. designed so that they cannot be tipped over or their contents spilled during handling or normal operation.
f. Seams that promote corrosion should be avoided. When a tray is fully loaded, the distance of the center of gravity from any side should be at least four times its g. Materials of construction that contact SNM in any distance from the bottom of the tray.. Racks, carriages, form should be selected so that surfaces do not corrode, conveyors, guides, or drive mechanisms that are used to dissolve, or erode during operation or during contact assist or direct the transport of trays should be designed with rinse solutions used for cleaning. Materials for so that individual trays cannot be tipped oi caused to construction of jaw faces, wear bars, or breaker plates of ride over one another.
comminution equipment should provide maximum resis tance to pitting or erosion. h. The use of blenders with internal mechanical agitators should be avoided. If agitators are used, they h. Structural integrity should be adequate to resist should be designed to permit areas to drain freely and to the formation of leaks, cracks, and crevices due to present minimum surface for the collection of solid thermal, vibratory, or other stresses. Transfer and particles.
instrument lines should be designed and installed so as to minimize mechanical stresses on interconnected equip i. Containment retorts or crucibles for packed-bed ment. conversion should be designed without recesses, internal flanges, or other uneven surfaces that would interfere i. Operating variables such as material flow rate, with the normal discharge of the bed material after moisture content, particle size, and vessel geometry conversion.
should be evaluated and selected to reduce undesirable formation of holdup (e.g., caking or sticking). 3. External Design j. Process units should be closely coupled and sized a. Visual access should be provided to surfaces or with minimal intervening holdup bins and containers, spaces where material is likely to accumulate. Alter consistent with good engineering design. natively, clearance should be provided so that either
5.42-5
external use of nondestructive assay instruments or with appropriate seals for drive shaft penetrations through glovebox walls.
internal probes can be used to detect the presence of SNM or to identify the location of residual material not
3 j. Provision should be made for charging and dis visually accessible.
charging of dry particulate material in the calcining operation by use of enclosed charge and discharge lines.
b. Dusting should be controlled and contained at the Continuous calciners should be equipped with exter charging and discharging ends of mechanical or pneu nally mounted vibrating mechanisms to ensure uniform.
matic conveyors. Pneumatic systems should be leaktight, flow of material throughout the calciner and to prevent and appropriate cyclones and filters should be used at the formulation of areas in which the material accumu the discharge end to separate solids from the carrier gas. lates.
In mechanical systems, the conveyor bodies should be enclosed to reduce the dispersement of airborne SNM k. Completely enclosed charge and discharge lines, material. ventilated hoods, or gloveboxes should be provided for all charging, discharging, or handling of SNM for c. Equipment should be arranged so that the routes blending, classifying, and comminution equipment. An of solids conveyors are as short as practical and have the exception may be material of a particle size or flow smallest number of bends and interconnections. characteristic such that no fines are released during handling. All openings, covers, or mechanical drive d. Exhaust ducts should be provided on all equip penetrations for blending, classifying, and comminution ment in which waste gases are generated (e.g., hoods, equipment should be sealed during operation to prevent gloveboxes, and pneumatic transfer equipment). The the spillage or release of SNM.
pressure inside exhaust ducts carrying SNM particulate should be sufficiently negative to prevent the loss of 1. Piping or tubing that is external to blending or material by leakage to surrounding areas. screening equipment and that may become plugged internally with particulate material should be equipped e. When large quantities of SNM particulates are with externally mounted vibrating mechanisms to ensure carried by exhaust gas streams, suitable devices (such as a uniform flow of material and should be removable for cyclones) should be employed to separate the bulk of inspection and cleaning.
such solids from the gas streams. Prefilters at the exit point in gloveboxes or enclosed equipment and final m. Retorts or containment shells used for packed bed filters prior to release should be used to remove operations such as uranium metal reduction should be particulates from exhaust gases. If measurable quantities adequately sealed to prevent the loss of SNM as vapor of SNM in fine particulates or vapors pass through a final during the reduction process. The materials used for the filter, a suitable wet scrubber should be installed in the construction of the containment shells for uranium exhaust system to remove them. When wet scrubbers are metal reduction should be compatible with the external used, consideration should be given to installing suitable furnace preheat atmosphere and with the insulating reheaters to prevent the corrosion of gas exhausters due material (refractory lining) used to separate the packed to condensation. bed from the retort so that the shells will not corrode or warp during operation.
f. Devices for measuring differential pressure should be installed around filters to indicate the accumulation 4. Design for Accommodating Cleanout of material containing SNM.
a. Equipment such as calciners and gloveboxes g. Drive motors and gear boxes for any solids should be provided with access ports, removable covers, conveyor should be mounted external to the conveyor, or -removable sides to allow visual inspection of the and the drive shaft should extend through a suitable internal surfaces.
leak-tight seal. Bearings for drives and idlers should be protected against the entrance of solids. b. Access ports or removable panels should be pro vided to facilitate cleaning of internal surfaces by h. Conveyor enclosures should be equipped with L,,ptopriate methods such as brushing, vacuuming, wash vibrating devices to reduce the quantity of solids ing, scraping, or rinsing to remove, dislodge, or dissolve adhering after a normal draindown. SNM particles.
c. Equipment should be provided with fittings as i. External surfaces of equipment installed inside connections for washdown and rinsing of internal gloveboxes should be smooth and free of crevices, surfaces of vessels and pipes. Air, steam, water, or cavities, and openings. Drives and power trains for appropriate chemical solutions may be used to dislodge, process equipment should be located outside gloveboxes, dissolve, or otherwise remove particulate process mate
3 rial, residues, and condensed vapors remaining on inter Regulatory Guide 5.23, "In Situ Assay of Plutonium Residual nal surfaces of the equipment.
Holdup," provides additional methods and procedures
5.42-6
(t. irovisin snould be made for flushing and draining i. The normal contents and all rinse solutions from and for removing and collecting any of the various rinses rotary retort-type calciners that contain lifting bars or in which SNM may be entrained or dissolved. Removal flight carriages should drain freely by gravity from the of material from blenders, calciners, comminution equip bottom of the calciner.
ment, or other equipment should be facilitated by designs that permit disassembly. Also, flush distribution devices should be connected at high points in the j. Containment shells or crucibles should be designed transfer lines or upper zones of equipment and should be with openings or access for thorough mechanical designed and arranged to allow flushing media to contact cleaning such as brushing or scraping to remove or the interior surfaces and cavities of the process equip dislodge all solid particles of SNM that may remain on ment and of auxiliary devices inside the equipment. internal surfaces after the equipment has been emptied.
Valves should be installed at appropriate locations in the system for complete draining. k. Mechanical equipment, jaw faces, and breaker plates should be capable of being disassembled and e. Supplementary mechanical equipment not per removed from crushers, disintegrators, or pulverizers for manently mounted should be capable of being disassem cleaning and inspection.
bled and removed for cleaning and inspection.
f. Provisions should be made to permit verification that all material has been removed from enclosed transfer lines or from other equipment such as blenders enclosed in gloveboxe
s.
D. IMPLEMENTATION
g. Filter media should be removable or capable of The purpose of this section is to provide information being backpurged while in position. Removable filter to applicants and licensees regarding the Regulatory media should be treated by leaching or by combustion staffs plans for utilizing this regulatory guide.
and leaching for the recovery and determination of This guide reflects current regulatory practice. There SNM. The design of cyclones should permit cleanout of fore, except in those cases in which the applicant residual solids and powders. proposes an acceptable alternative method for comply ing with specified portions of the Commission's regula h. Ducts should be fabricated so as to be easily tions, the method described herein will be used by the disassembled. For example, taped joints may be used to Regulatory staff in evaluating all license applications facilitate disassembly. docketed after publication of this guide.
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