ML20039C737
| ML20039C737 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/22/1980 |
| From: | BECHTEL GROUP, INC. |
| To: | |
| Shared Package | |
| ML20039C723 | List: |
| References | |
| 13587-2-N01-100, 13587-2-N1-100, NUDOCS 8112300096 | |
| Download: ML20039C737 (19) | |
Text
Design Criteria 13587-2-N01-100 L
ex GPU SERVICE CORPORATION THREE MILE ISLAND - UNIT 2 REC 0VERY FACILITIES DESIGN CRITERIA DOCUMENTS COVER SHEET
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eE JOB NO. 13587 REV.
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J' DESIGN CRITERI A DOCUMENTS DisclPLINE rgjCN.ff'L Nuclear
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Design Criteria 13587-2-N01-100 SHIELDING DESIGN AND ACCESS CONTROL
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DESIGN CRITERIA TABLE OF CONTENTS PAGE 1.0 GENERAL 1
2.0 GUIDELINES FOR GENERAL ARRANGEMENT AND SHIELDING 2
3.0 SOURCE TERMS 3
4.0 ACCESS CONTROL AND RADIATION ZONING 4
5.0 AREA RADIATION AND AIRBORNE RADI0 ACTIVITY MONITORING 6
6.0 ALARA DESIGN CRITERIA AND CONSIDERATIONS 7
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D2 sign Critoria 13587-2-N01-100 s
- 1. 0 GENERAL
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i 1.1 The primary objective of the shielding design and access control will be to protect operating per sonnel and the general public front potential radiation sources in the reactor, power conversion system, radwaste system, and other auxiliary systems, including associated equipment and piping.
Shielding will be designed to perform the fol-lowing functions:
a.
Limit the dose to plant personnel, construction workers, vendors, and visitors during cleanup, recovery, and inspection to within the requirements of 10 CFR Part 20 and to meet the intent of Regulatory Guide 8.8.
b.
Limit the dose to unit personnel to within the requirements of 10 CFR Part 50, Appendix A, Criterion 61, Fuel Storage and Handling and Radioactivity Control.
c.
Limit the dose rate to certain components'in high-radiation areas within specified radiation tolerances.
d.
Limit dose to persons at the boundary of the restricted area, due to direct radiation during normal operation, to a value no greater than 10 CFR Part 20 limits.
e.
Limit dose to persons at the site boundary due to direct radiation during normal operation to a value less than CiLj 40 CFR Part 190 limits.
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D2 sign Criteria 13587-2-N01-100 y
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2.0 GUIDELINES FOR GENERAL ARRANGEMENT AND SHIELDING 2.1 The following guidelines will be used for equipment layout and -
shielding of the plant.
These guidelines will be used as the design basis for initial shielding design, such as" determination of shield wall thickness, materials, and locations. As the detailed facility design develops, an ALARA review of the facility will be made.
This review may result in the inclusion i r;f Edditional permanent or temporary shielding in excess of that indi-cated by the design criteria in order to achieve a fully acceptable design from an ALARA' standpoint.
All systems containing radioactivity will be identified and shielded, f
based on the access requirerrents of the area.
All areas within the
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Owner-controlled area will oe divided into zones, with dose rate levels and anticipated access as shown in the following table based on source terms for normal:op'eration.
TABLE 1 RADIATION ZONES y
ZONE DESIGN DOSE RATE ACCESS DESCRIPTION
-(MREM PER HR)
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I 50.5 (Note 1)
Uncontrolled, Unlimited Access r
II 0.5-2.5 Controlled, Limited Access 40 Hrs Per Week i
III 2.5-25 Controlled, Limited Access 4 to 40 Hrs / Week IV.
25-100-Controlled, Limited Access 1 to 4 Hrs / Week V
100 1000 Normally Inaccessible Access During Emer-gency VI 1000-3000 Normally Inaccessible Access During Emer-gency Locked Barrier to Zone VII 23000 Normally Inaccessible Access During Emer-gency Locked Barrier to Zone NOTE 1:
Design dose rates in office spaces and other Zone I areas which are continuously occupied eight hours per day, five days a week or more, shall be less than 0.25 mrem /hr.
Corridors and other Zone I areas of a transient ~ occupancy nature shall be below 0.5
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mrem /hr.
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Design Criteria 13587-2-N01-100 j
i rf 3.0 SOURCE TERMS
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3.1 During the initial containment decontamination effort, solid, liquid, and airborne activities will have to be monitored.
Direct radiation sources will be from contamination plateout on all such sur-faces, the reactor coolant system, fuel, and equipment.
The sources 1
involving different isotopes will be divided into six energy bins cor-responding to the next highest gamma energies of 0.4, 0.8, 1.3, 1.7, 2.2, and 2.8 Mev.
The contribution from individual sources will be calculated based on the model described below.
The total dose to the receptor will be taken as the sum of the doses from each source.
3.2 The geometric model assumed for shielding evaluation of tanks, heat exchangers, filters, demineralizers, and evaporators will be a finite cylinder source and for piping, an infinite shielded cylinder.
Corrosion products deposited on the surfaces such as pipe will be treated as a cylinder surface source.
The mathematical models will be based on the formulations in:
a.
Reactor-Shielding Design Manual, edited by Th. Rockwell III, first edition, Van Nostrand, New York,1956.
b.
Engineering Compendium on Radiation Shielding, edited by R. G. Jaeger, E. P. Blizard, A. B. Chilton, M. Grothenh: 's, A. Honig, T. A. Jaeger, and H. H. Eisenlohr, Springer-Verlag, New York, 1968.
c.
Various technical papers on buildup factors.
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Design Criteria 13587-2-N01-100 4.0 ACCESS CONTROL AND RA01ATION ZONING 4.1 Access to areas inside the plant structures and plant yards is regulated and controlled by radiation zoning and access control.
Each radiation zone defines the radiation level range to which the aggregate of all contributing sources must be attenuated by shielding.
4.2 All plant areas are categorized into radiation zones according to expected radiation levels and anticipated personnel occupancy with consideration given to maintaining personnel exposures as low as rea-sonably achievable and within the standards of 10 CFR 20.
Each room, corridor, and pipeway of every plant building is evaluated for potential radiation sources during clean-up operations for maintenance occupancy requirements; for general access requirements; and for material exposure limits to det+nnine appropriate zoning.
Radiation zone categories employed and their descriptions are given in Table 1.
All frequently accessed areas, e.g., corridors, are shielded for Zone I or Zone II access.
The control of ingress or egress of plant operating personnel to con-trolled access areas and procedures is employed to assure that radiation levels and allowable working times are within the limits prM eribed by 10 CFR 20.
Whenever practicable, the measured radiation level and the location of the source are posted at the entry to any radiation or high radiation
.s area.
4.3 The access zones for each area will be determined based upon the radioactive sources, process equipment to be shielded, adjacent zone re-quirements, and maintenance requirements.
Efforts will be made to locate processing systems in such a manner as to minimize exposure to plant personnel.
Plastic tents and ventilation hoods will be required over all decontamination tanks to minimize the dispersion of airborne contaminants.
Concrete shield walls will be provided around the decon-tamination and storage areas.
4.4 In the design of the cleanup and recovery facilities, permanent and temporary shielding will be incorporated.
Concrete walls and labyrinths are used to shield general access areas from high radiation storage or waste processing rooms.
Outside perimeter facility walls will be built based upon shielding calculations.
Steel or lead plate may be substituted where necessary in the design of these structures.
4.5 The use of temporary shielding will be required on a case-by-case basis. This will especially be necessary when extremely contaminated equipment is to be prepared for further decontamination.
Where possible, transport of equipment within the fccility will be done via shielded forklift trucks and monorails.
As equipment is removed from the con-tainment, lead blankets or bricks may be arranged around the transfer cart to minimize exposure to working personnel and to minimize the area radiation level.
Concrete block can also be used for temporary shielding along permanent shield walls in case more shielding is required from Page 4 Rev. O
D2 sign Criteria 13587-2-N01-100 time to time.
The block can be stacked up around open hatches or door-ways where " shadow" shielding may be necessary. Another temporary i
shielding method is the ui,e of lead shot bags placed over equipment or "50t" pipes where adequate support structures exist.
Entire systems, both old and new, will have +o be reviewed to determine whether permanent or temporary shielding is required for maintaining low J
radiation levels in general work areas.
The new facility shield design will be based upon estimation of the maximum radiation sources to be located in the building.
A thorough review of waste activities and quantities to be processed in each building will be conducted. Wastes such as spent resins, demineralizer beds, compacted trash, and evaporator bottoms have to be considered.
The main facilities to be reviewed are the waste staging area, equipment decontamination building, containment recovery service building, and any new solidification systems.
Upon reentry into the containment, major areas of interest will be surveyed to establish allowable working periods. The initial dose rates are expected to range from 1.0R/hr. to 10.0R/hr. deg nding on the location inside the containment vessel (excluding the reactar cavity).
Areas such as the floor hatch at the 305' level, air cooters, and the top of the steam generator compartments may have to be temporarily shielded.
As decontamination proceeds and the general area radiation levels decrease, relative " hot spots" will be identified and be either removed or shielded by lead blankets, concrete block, or other shielding techniques.
The shielding criteria and design in the auxiliary building is based on f
the shielding of processing equipment, resin tanks and the transfer of spent resins and solidified waste.
Because of the high initial radio-
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active levels of the liquid to be processed,-additional shielding may be required.
Also the radiation zone designations may have to be re-evaluated during processing of these high level wastes.
The traffic paths for the removal of the spent resins and filter cartridges may have to be roped i
off during transfer to the solidification processing area.
The two permanent waste staging facilities will be provided with a decontamination section and a truck loading bay. Containers will be 1
separated by low, medium, and high activity.
Very high activity drums may require some temporary shielding.
The building walls will be of r
sufficient thickness so that neither the site boundary nor the protected fence radiation limits will be violated.
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Dasign Critzria 13587-2-N01-100 5.0 AREA RADIATION AND AIRBORNE RADI0 ACTIVITY MONITORING 7
b 5.1 Area radiation monitoring is provided to supplement the personnel and area surveying capabilities to ensure compliance with the personnel radiation protection guidelines of 10 CFR 20, 10 CFR 50, 10 CFR 70, and Reguletory Guides 8.2, 8.8, and 8.12.
Both gamma and beta radiation detectors will be located throughout the plant.
These monitors will be permanently mounted in general occupancy areas.such as Zones I and II.
Portable monitors will be used where the task requires plant personnel to be in areas of mid to high radiation zones.
Airborne particulate activity can be a significant problem during gross decontamination efforts.
5.2 Consistent with this purpose, the area radiation monitors function to:
a.
Immediately alert plant personnel entering or working in non-radiation or low-radiation areas of increasing or abnormally high radiation levels which, if unnoticed, could possibly result in inadvertent overexposures.
b.
Inform the control room operator of the occ.urrence and approx-imate location of abnormal radiation increase in non-radiation or low-radiation areas.
c.
Comply with the requi-ements of 10 CFR 50 Appendix A, General C,' f Design Criterion 63 for conitoring fuel and waste storage and handling areas.
d.
Certain monitors located near the spent fuel pool act as criticality alarm monitors and conform to the requirements of 10 CFR 70 and Regulatory Guide 8.12.
e.
A monitor is provided for use in assuring that solidified radwaste containers meet the requirements of 10 CFR 71 and 49 CFR 173 with respect to the radiation level on contact with the container and at certain distances from the container.
This monitor will warn personnel when containers need additional shielding.
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Design' Criteria 13587-2-N01-100 6.0 ALARA DESIGN CRITERIA AND CONSIDERATIONS The following items form the basis for the THI-2 Recovery Project ALARA program.
During the design process, the applicable items shall be considered and incorporated into the design as appropriate.
6.1 FACILITY ARRANGEMENT 6.1.1 Facility Layout a.
Check that equipment with contact radiation levels of Zone III or greater are separated frort Zone II and lower areas by shield-ing or distance plus access barriers, b.
Check that major equipment which by design accumulates or concen,trates radioactivity with Zone III or greater contact radiation levels is shielded or separated from adjacent active and passive equipment to meet the applicable radiation shielding criteria for adjacent areas.
c.
Check that equipment compartments are arranged 50 that radiation zone differences between adjacent areas are minimized.
d.
Check that personnel access control and traffic patterns are considered to minimize spread of contamination during all facility operating modes.
CY e.
Check that active components in clean (non-radioactive) services are not located in Radiation Zones III or greater.
f.
Check that equipment subject to removal or replacement has adequate aisles or area access and built-in provisions (such as monorails, jib cranes, etc.) for removal.
g.
Check that access to components requiring frequent maintenance, inservice inspection, adjustment, etc., is from the lowest practicable radiation zone and not via a Zone V.
h.
Check that adequate space and facilities are provided for clothing change stations outside contaminated areas.
i.
Check that all corridors and normal traffic area are Zone I or II.
6.1.2 Equipment Location a.
Check that adequate space is provided around equipment to allow ease of maintenance.
b.
Check that equipment maintenance envelopes include estimated size of rigging requirements and temporary shielding, if required.
c.
Check that laydown area requirements for equipment are available.
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Dasign Critsrip 13587-2-N01-100 d.
Check that equipment which requires routine maintenance, service, testing, or inspection such as instruments, sample stations, or rotating components is located to provide maximum direct access.
e.
Check that the clear space for doorways is minimum 3 feet by 7 fee +,and that there is adequate access for personnel, tools, and component removal.
f.
Check that equipment manways are readily accessible.
6.1.3 Specific Component Layout a.
Filters Check that adequate space is provided for semi-remote removal, cask loading, and transporting spent radioactive filter car-tridges to the solid radwaste area.
b.
Pumps 1)
Check that small pumps are oriented in a manner which allows easy removal from the area.
2)
Check that adequate access is provided for pump seal replacement.
c.
Tanks
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1)
Check that direct access and removal space is provided for motors of tank agitators.
2)
Check that direct access to active components or rcanways is provided into the upper levels of tank rooms as well as the lower elevations.
3)
Check that adequate space is provided for tank internals cleaning operations.
d.
Evaporators 1)
Check that concentrates and distillate components are adequately separated.
2)
Check that components which accumulate radioactivity or crud such as heating tubes are separated from active components such as valves.
3)
Check that adequate space is provided to allow uncom-plicated removal of heating tube bundles.
e.
Sample Stations 1)
Check that sample stations for routine sampling of process fluids are separated by shielding or distance from other radioactive components to Zone II levels.
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Dasign Criteria 13587-2-N01-100 2)
Check that local ventilation (e.g., a hood) is provided at sample stations containing radioactive materials.
f.
Ventilation System Components 1)
Check that ventilation fans and filters are provided with adequate access space to permit servicing.
2)
Check that outside air supply and building exhaust system components are enclosed by a ventilation barrier and are in areas no greater than Zone II.
3)
Check that general ventilation flow is from areas of po-tential (or actual) low contamination to areas of poten-tial (or actual) high contamination.
g.
Instruments 1)
Check that instruments which require periodic attention are located in Zone II (or lower) areas whenever possible.
2)
Check that, if instruments must be located in Zone III or greater, they are mounted so that they are readily acces-sible for maintenance and calibration and are easily removable to a lower radiation zone for extended servicing or calibration.
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3)
Check that, if control valves must be located in Zone IV j
or greater, appurtenances such as E/P converters, airsets, and solenoid valves are not mounted on the control valve but are located in a lower radiation zone.
l 6.2 SHIELDING 6.2.1 Bulk Shielding a.
Check that shielding or separation is provided between radia-tion zone areas to meet the radiation level criteria for adjacent areas.
b.
Check that shielding design is based on conservative or measured radiation source term, component design, and plant layout assumptions.
c.
Check that poured concrete density specifications are consistent with shielding design basis minimum densities, d.
Check that concrete block density specifications are consistent with shielding design basis minimum densities.
e.
Check that concrete block wall designs meet or exceed the minimum shielding requirements.
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Design Critoria 13587-2-N01-100 f.
Check that removable or temporary shielding is designed con-sistent with applicable radiation shielding criteria for adjacent i
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areas.
6.2.2 Penetration and Discontinuity Shielding a.
Check that penetrations, such as H&V ducts and piping, are either located with an offset between radiation sources and accessible areas or are appropriately shielded.
a.
Check that penetrations are located as far as possible above the accessible floor elevation.
c.
Check that penetration shielding is provided as necessary to meet the radiation shielding criteria in adjacent accessible areas.
d.
Check that seismic gap shielding is provided to maintain radia-tion levels in adjacent accessible areas within radiation shielding criteria limits.
6.2.3 Entryway Sh'ielding Check that adequately shielded labyrinths or hatches are provided to limit direct and scattered radiation out of shielded areas.
6.3 SYSTEM DESIGN 6.3.1 Decontamination Provisions a.
Check that radioactive systems with Zone V component radiation levels have provisions to flush the entire system.
Flushing capability should be available even if the system pump is inoperable.
b.
Check that major components of the primary coolant purification system where crud can collect up to Zone V radiation levels such as filters, heat exchangers, etc. have provisions for chemical decontamination including low point drains.
Check that means are available to take the decon solution to chemical waste area.
c.
Check that seal flush water is provided to pumps with chemical ne slurry wastes.
d.
Check that all serviceable components have isolating and draining capability.
e.
Check that provisions are available to flush potentially con-taminated instrument lines.
f.
Check that flush connections are located downstream of the h
component isolation valve at the high point or low point of the Page 10 Rev. 0
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D sign Critsria 13587-2-N01-100 inlet line and upstream of the isolation valve at the low point Ce l-or high point of the outlet line and as close as possible to the inlet and outlet connections of the component.
g.
Check that isolation valves are provided on the flush con-nections and are located as close as possible to the main pipe.
h.
Check that all flush connections are equipped with quick connect /
disconnect fittings.
6.3.2 Remote Operation and Instrumentation a.
Check that adequate process instrumentation and controls are available to allow system and component operation from a low radiation zone.
b.
Check that filters which accumulate high radioactivity are designed with the means either to backflush the filter remotely or to perform cartridge replacement with semi remote tools.
i c.
Check that probe type instruments are used on highly radio-active tanks containing two phase materials.
6.3.3 L skage Provisions a.
Check that tank overflow lines are directed to the waste collec-tion system.
b.
Check t' hat sludge tanks and air mixing tanks which contain radioactive materials are vented to the respective building ventilation system or the vent collection system.
c.
Check that strainers are included in vent lines from tanks containing spent resins or sludge.
6.3.4 Demineralizers a.
Check that demineralizers in radioactive systems and associated piping are designed with provisions for being flushed with demineralized water.
b.
Check that strainers are located immediately downstream of ion excnangers.
c.
Check that drains and downstream strainers are designed for full system pressure drop.
d.
Check that strainers are included in vent lines from the demin-eralizer vessel.
e.
Check that flush connections are provided at all critical locations (such as elbows, ties, valves) to clear potential plugs.
Page 11 Rev. 0
Design Criteria 13587-2-N01-100 f.
Check that flow in piping is tu'bulent enough to maintain C_..
suspension of fines.
6.3.5 Floor Drains o
a.
Check that equipment drains are piped directly to a drainage collection system.
b.
Check that provisions are made to remove plugging should it occur in drain lines.
c.
Check that radioactive and potentially radioactive drains are separated from non-radioactive drains.
6.4 PIPING AND VALVE DESIGN 6.4.1 Pipe Routing a.
Check that piping containing radioactive materials is routed through suitably zoned, controlled access areas in accordance with piping radiation classification as s,
.' in Table 2.
b.
Check that equipment compartments contain radioactive piping associated only with equipment within the compartment or that non-associated piping is adequately separated.
c.
Check that where it is necessary for radioactive piping to be C~.'
routed through corridors or other radiation zone areas, shielded ic:
pipeways are provided to meet area radiation level requirements.
d.
Check that long runs of exposed radioactive piping are mini-mized, particularly in active component areas such as valve galleries or pump cells.
e.
Check that radioactive piping is routed to take credit for shielding effects of equipment or structures.
l 6.4.2 Valve Location a.
Check that valves are separated from components which accu-mulate or contain radioactivity by shielding or distance to meet the applicable radiation shielding criteria levels.
I b.
Check that valves are readily accessible from floors or permanent platforms.
c.
Check that sufficient space is provided to facilitate valve and valve operator maintenance, operations and testing.
d.
Check that valves are not located in radioactive pipeways.
Check that vent and drain isolation and instrument root isolation e.
valves are located close to process piping or components.
Page 12 Rev. 0
Drsign Critaria 13587-2-N01-100 f.
Check that process valves are not located at low points in 4-h:
piping.
g.
Check that reach rods or remote manipulators are provided for manually operated valves in potentially high radiation areas.
6.4.3 Pipe Design a.
Check that branch lines having little or no flow during normal operation are connected above the horizontal midplane of the main pipe.
b.
Check that thermal expr'sion loops in radioactive systems are raised, rather than dr > ped.
c.
Check that orifices art located on vertical piping runs if possible.
If located in horizontal piping runs, use eccentric design of the orifice.
d.
Check that reducers are installed not to form a stagnant pocket, i.e., use eccentric design with bottom flat, except at pumps.
e.
Check that bypass lines are laid out to allow draining and flushing the main line without disruption of system operation.
f.
Check that lengths of radioactive pipe runs and number of bends are minimized.
g.
Check that low points and dead legs in radioactive piping are minimized and are capable of being flushed.
h.
Check that instrument and sensing line connections are located in such a way as to avoid corrosion product and radioactive gas buildup.
i.
Check that welded joints are used whenever possible to minimize crud traps in the mechanical joints.
6.4.4 Valve and Valve Operator Selection a.
Check that full ported valves are used in systems expected to handle spent resins or slurries with radiation levels of 25 mr/hr or greater at contact with the surface of the pipe.
(See Table 2) b.
Check that valves 2-1/2" and larger (except butterfly valves and plug valves) in lines carrying radioactive fluids with radiation levels of 25 mr/hr or greater (contact dose rate) are diaphragm, packless, or have a double set of packing with lantern ring.
c.
Check that all globe valves (excluding instrument valves) 2" and smaller are Y pattern globe valves to facilitate rodding if
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plugging should occur.
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Dasign Critsria 13587-2-N01-100 d.
Check that plug valves or equal are used on systems trans-porting resins and sludge and radwaste systems, e.
Check that remote operators are provided for all valves in lines pmcessing evaporator bottoms or spent resins.
f.
Check that minimum volume valves are provided for vents and drains to minimize the internal surface area for deposition.
g.
Check that pressure relief valves have flange connections to facilitate removal for set pressure verification and calibra-tion.
6.4.5 Spent Resin and Sludge Piping a.
Check that resin lines are continuously sloped in direction of flow to avoid potential stagnant pockets, b.
Check that valves are located as close as possible to the spent resin tank room to minimize the length of the dead leg.
c.
Check that flow control valves and orifices are not used in resin lines, d.
Check that long radius (greater than 1.5 times the pipe diameter; bends and elbows are used at direction changes.
i e.
Check that directional changes and msin piping runs are mini-mized.
6.5 COMPGNENT DESIGN FOR COMPONENTS CONTAINING RADI0 ACTIVE FLUIDS OR LOCATED IN HIGH RADIATION AREAS l
6.5.1 Specifications l
l a.
Check that material requisitions specify the radiation envi-ronmental requirements for the intended material application.
b.
Check that equipment design features as presented in the remainder of this Section are included in the appropriate equipment specification.
6.5.2 Heat Exchangers a.
Check that corrosion resistant tubes of stainless steel or other suitable material with tube-to-tube sheet joints welded are proviaed to minimize leakage.
1 b.
Check that impact baffles are provided with tube-side and shell-side velocities limited to minimize erosive effects.
l c.
Check that drains are provided on the lowest portion to ensure
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removal of contaminated fluids.
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Design Criteria 13587-2-N01-100
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d.
Check that where practical the contaminated side of the heat
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exchanger operates at a lower pressure than the clean side.
6.5.3 Evaporators O
Check that chemical addition connections are provided to allow use of h
chemicals for descaling operations.
6.5.4 Pumps (Small) a.
Check that pump casings are provided with drain connections.
b.
Check that pumps in radiation areas (Zone III or higher) are purchased with mechanical seals to reduce seal servicing time.
c.
Check that pumps in radioactive systems are provided with flanged connections for ease in removal.
d.
Check that electrical quick disconnects are provided on pumps in high radiation zones (V or higher).
e.
Check that painted surfaces of the pump (if any) are painted I
with a radiation resistant and decontaminable coating.
f.
Check that the pump has long-lived bearings and that lubrica-tion is permanent type.
g.
Check that the pump selection has considered the use of low RPM designs.
6.5.5 Tanks a.
Check that tanks in radioactive service are provided with sloped bottoms (min. 1" per foot of tenk diameter) and bottom outlet connections.
Conical or dished bottom tanks with bottom connections are acceptable.
b.
Check that adequate tank mixing is provided to prevent crud settling.
c.
Check that each tank requiring a manway is top fitted with one of at least 2 feet in diameter.
(If a manway is located on the side of a tank, it should be clearly demonstrated that it is
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necessary.)
d.
Check that side manways have eccentrically hinged covers designed to easily clear fastening studs.
e.
Check that outlet pipes have backflush capability into the tank to break up sediment.
Backflush capability should include air.
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f.
Check that tank linings (if any) are suitable for the expected
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service.
Epoxy paint should be avoided.
Page 15 Rev. 0
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0: sign Criteria 13587-2-N01-100 g.
Check that overflow lines are lower than vent lines to prevent
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fluid from contaminating vent lines.
h.
Check that a permanent connection is provided for insertion of a hydrolaser unit for decontamination of tanks in Zone V areas.
i.
Check that lap joints were not used in tank construction.
j.
Check that no backing strips were used oil tank welds.
k.
Check that backing rings were not used on nozzle welds.
1.
Check that siphoning of liquid waste from tanks cannot occur.
Check that in-line filters with back flushing capability are m.
provided for tanks with a sludge build-up potential, Check to assure that tanks with a potentially hazardous leakage n.
consequence are located over catch pans or within curbs with drain lines leading to radioactive liquid waste storage tanks or to sumps capable of handling a potential spill.
6.5.6 Instruments a.
Check that chemical seals are provided on sensing lines on process piping which may contain high amounts of solids.
b.
Check that primary instruments which, for functional reasons, are located in high radiation zones (V and greater) are designed for easy removal to a radiation zone II, or lower, for calibration.
c.
Check that instruments are selected which contain minimal quantities m' contaminated working fluids; e.g., pressure transducers rather than bellows-type pressure gauges.
6.6 MISCELLANE0US FACILITY DESIGN 6.6.1 Lighting a.
Check that muittple electric lights are provided for each cell or room containing highly tadioactive components (Zone V and greater) so that burnout of a single lamp will not require entry.
b.
Check that lighting in high radiation areas (Zone V and greater) is actuated from outside the area in the lowest practicable radiation zone.
c.
Check that sufficient lighting is provided in areas that contain remote viewing devices to allow their efficient use.
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