ML20236W889

Criticality Safety Evaluation License Annex Ammonium Diuranate Fuel Rod Mfg

ML20236W889
Person / Time
Site:	Westinghouse
Issue date:	07/31/1998
From:	WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
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ML20236W887	List: ML20236W889
References
NUDOCS 9808060280
Download: ML20236W889 (22)

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{{#Wiki_filter:. 4 CSE LICENSE ANNEX ADU FUEL ROD MANUFACTURING i l l 1 9808060280 980731 {DR ADOCK 07001151 PDR

l CSE LICENSE ANNEX l l. I ADU FUEL ROD MANUFACTURING l l TABLE OF CONTENTS l TA BLE OF CONTEN75 .________________._._.__,_,_,__,,,,,,,,,,_,,,,,,,,,,,,,,,,,,,,,,, y REVISION RECORD ...II l PROCESS

SUMMARY

Assemble FuelRodComponents.. ,.1 Load Fuel Tubes-- .1 FuelRodFabrication.. .2 QCInspection Area.. .2 ADUFuelRodScrap/ Rework Area.... .2 Manufacturing Operating Procedures.. ,. 3 ENVIRONMLWTAL PROTECTION AND RADIATION SAFE 1Y CONTROLS : =4 NUCLEAR CRITICALITY SAFETY (NCS) CONTROLS AND FAULT TREES. .4 Loading ADUPellets And Welding ADUFuelRods... .5 QCInspection Area - .8 ADUFuelRcdScrap/ Rework Area.. . 10 CitEMICAL 3AFETY AND FIRE SAFETY CONTROLS --

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l 1 i Initial Issue Date: 31 JUL 98 Page NO. i Revision Date: Revision NO.,_0 l l _._.______.._.__________a

CSE LICENSE ANNEX ADU FUEL ROD MANUFACTURING REVISION RECORD REVISION DATE OF PAGES REVISION NUMBER REVISION REVISED RECORD l l l i Initial Issue Date: 31 JUL 98 Page No. ii Revision Date: Revision No. O

l CSE LICENSE ANNEX l ADU FUEL ROD MANUFACTURING l Process Summary The scope of this document includes the process description of the systems and components used to fabricate nuclear fuel rods in the ADU Fuel Rod Area of the Columbia Plant. The ADU Fuel Rod Area involves the following areas: The assembly of fuel rod components. The loading of fuel tubes with pellets. The fabrication and inspection of fuel rods. l e The scrapping and/or rework of fuel rods. i l Also included are the controls and features of the systems and structures that may affect l criticality safety analyses and evaluations. j Excluded from the scope of this criticality safety evaluation are the following: I IFBA fuel rod fabrication (included in the CSA for IFBA Fuel Rods). e Fuel assemblies in shipping containers (part of separate shipping container license). Tube fabrication and component cleaning. i Final assembly (included in the CSA for Final Assembly Area). e - Assemble Fuel Rod Components i Tubing which has been marked with a bar-code, bottom plugged and welded, and l inspected is picked up from the tube fabrication lines. Cleaned and released top end fuel rod plugs, fuel rod springs or other mechanical components, as applicable, are picked up from the Component Cleaning Area. Load Fuel Tubes F Tubing is brought into the Chemical Area and placed at the loading station and i positioned for pellet loading. Pellet carts with enriched and/or blanket material are staged at the pellet loading station. Pellet trays are removed from the cart and positioned at the vibratory loader where the pellets are introduced into the fuel tube. A i gage is used to check the length of the as-loaded pellet stack. Filler pellets are added to l the pellet stack until the gage is satisfied. A dimensional check of the plenum area is done where the pellet stack is again adjusted using filler pellets until the plenum gage is i Initial Issue Date: 31 JUL 98 Page No. 1 Revision Date: Revision No. 0 a

i satisfied. Pellets that are seen to be damaged during loading are removed and placed in I an approved, online scrap container. Any pellets that collect on the floor of the enclosure or the pellet loading station are removed when approximately two dozen pellets are collected. The online scrap container is emptied when it becomes full. I Fuel Rod Fabrication ' After pellet loading is completed, the loaded fuel rods are transferred to the fabrication portion of the fuel rod line. The end of the tube is then cleaned to remove any pellet dust.. A spririg or other mechanical device is inserted in the fuel rod _ to prevent the pellet stack from shifting. The fuel tube is closed by inserting a top end plug into the open end of the tube. The completed fuel rod is then transferred to the weld line. At the weld line, the fuel rod receives a top girth weld before being transferred to the seal welder. At the seal weld station, the fuel rod is pressurized with helium and then seal welded. The fuel rods are then transferred to a collection area where they are loaded onto twenty-five rod carriers before being sent to the QC Inspection Area on the clean side. QC Ina'pection Area At the QC Inspection Area, completed fuel rods arc staged at the fuel rod weigh scales. The fuel rods are individually weighed and then transferred to the leak detector in groups of twenty-five where the hermeticity of the fuel rods is checked. After the leak check is completed, the fuel rods are transferred to either ultrasonic or x-ray inspection devices where the welds are inspected for internal integrity. The fuel rods are then positioned at the active gamma scanner where automatic inspections are made for the pellet stack length, enrichment, gaps, and the presence of a spring / retaining device. After active gamma scan the fuel rods are placed into small (25-rod) channels and u staged at the Dimensional and Visual (D & V) Area. The fuel rods are placed on a surface plate and dimensionally inspected for length and straightness; a visual inspection is made of the welds and fuel rod surfaces for defects. Released fuel rods are placed into large channels for use in the Final Assembly Area. ADU Fuel Rod ScrapIRowork Area i (- Fuel rods that are not needed for the fuel region for which they are built, or that do not meet drawing or inspection limits, are held for rework or scrapping. The top end plug is removed using a lathe and the tube end is faced. I

If the fuel rod is to be scrapped, it is taken to the pellet dump hood where pellets are dumped into an' approved scrap container. The pellet dump hood is connected to the exhaust system to prevent any airborne contamination. The emptied tube is cut into InitialIssue Date:

31 JUL 98 Page No. 2 j . Revision Date: Revision No. _O i

sections using a lathe or tubing cutter, and held for recycling. When the approved scrap container is full of pellets, the container is sealed and transferred to the Scrap Recycling Area. Fuel rods are reworked using approved rework procedures. When the rework operation . is completed, a new top end plug will be put on in place of the old one. The reworked fuel rod is transferred to one of the fuel rod lines to complete its fabrication. After fabrication is complete, the reworked fuel rod is processed using normal operating procedures. 1 J Fuel rods that have a tube defect can have the pellets recovered and reloaded into new tubes. The top and bottom end plugs are removed from the fuel rod and moved to a pellet transfer fixture. The fixture will push the pellets out of the tube onto a receiving fixture where the pellets are inspected for damage. Damaged pellets are replaced prior to the new tube being loaded. The new tube is loaded and the pellet stack is checked using the manual gage. The stack is adjusted using filler pellets. The new fuel rod is then processed using normal fuel rod fabrication and inspection equipment. All fuel rods are maintained in a one high array in the Fuel Rod Manufacturing Area, or are placed in small channels for scrap / rework, or large channels for storage. Small channels are maintained a minimum 8-inches edge to edge vertical spacing from other units; large channels are maintained a minimum 12-inches edge to edge vertical spacing from other units. Manufacturing Operating Procedures C1 mQA WMME ^iW9M%- ff f]b ' N K[4 lI 52 - @ DOG 26BhlT ;., @%NCN35t' M K W odlMENTTITI I D s MOP-735306 Rod & Channel Handling For Rod Storage Area MOP-735307 Rams Instructions For Fuel Rod Storage Area MOP-736903 toad Fuel Rods into Fuel Rod Box . MOP-736905 Authorized Material-Fuel Rod Storage Area MOP-750258 Receive And Segregate Defective ADU Fuel Rods MOP-750275 ADU Fuel Rod Weighing Procedure MOP-750276 Rams Instructions For Fuel Rod Loading Area MOP-750281 Abrading Of Oversized Welds Or Cocked End Plugs 1 MOP-750282 Plug Rods And Tubes In Rod Rework Area MOP-750286 Loss Of Power And Water - Rod Area MOP-750287 Fuel Rod Handling MOP-750290 Girth Weld Fuel Rod End MOP-750291 Pressurize And Seal Weld Fuel Rods ) Initial Issue Date: 31 JUL 98 Pay No. 3 Revision Date: Revisicn No. _0

?gDOCUMENTy At - gjp,w }[ f. -(l[' A#p NUMBER % a. - n::DOCUMENTM. MOP-750295 Remove Of Bottom End Plug From Tube MOP 7502% Clean Fuel Rod Production Equipment MOP-750297 Remove Top End Plug MOP-750299 Regaging Reworked Fuel Rods MOP-750300 Polish Small Visual Defects On Fuel Rods MOP-750301 Depressurization Of Fuel Rods MOP-750302 Rod To Tube Pellet Transfer MOP-750303 Control Of Rods Between Rod Area And Rod Scrap Area MOP 750309 Salvage Tubes From Rejected ADU Rods MOP-750353 General Operating Procedure - ADU Rod Area MOP-750566 Scrap ADU Rods MOP-758878 Rod Area Cleanout For Enrichment Change MOP-759006 ADU Fuel Rod Staging Area Instructions QCI-920101 Weld Radiograph Inspection QCI-920102 Girth & Seal Weld X-Ray Oper (3 251010) QCI-920103 Ultrasonic Testing of Fuel Rods Welds QCI-922102 Automated Helium leak Test QCI-923103 Thru-Wall Inspection-Scanner 3 & 4 QCI-924101 Fuel Rod D&V Inspection QCI-928024 X-Ray Fluoroscope Units for Non-Fuel Insp QCI-928025 Helium leak Test for Batch Systems (Var) QCI-928103 Girth & Seal Weld X-Ray Procedure QCI-928106 X-Ray Film P ocessing (Automatic) QCI-980219 QC Insp & Release of Pellet Coater Runs (Q@S) Environmental Protection and Radiation Safety Controls To be provided in a future Integrated Safety assessment Nuclear Criticality Safety (NCS) Controls and Fault Trees The scope of this document includes: I' The loading of ADU tubes with ADU pellets arv! the fabrication of ADU fuel rods. The QC inspection of ADU and IFBA fuel tods. Initial Issue Date: 31 JUL 98 Page No. 4 l Revision Date: Revision No. _0

Scrap / rework of ADU fuel rods. o This CSE for ADU fuel rod loading, fabrication, QC inspection, and scrap / rework comprises the criticality safety evaluation for the ADU Fuel Rod Manufacturing Area of the plant. This CSE also comprises the criticality safety evaluation for processing IFBA Fuel Rods in the QC Inspection Area. Excluded from the scope of this CSE are the following: -e' Production of pellets, including tray transport to the tube loading stations. e' Transport of fuel rod channels from the fmal QC inspection station. . Handling of pellets (removed from scrap / rework fuel rods) in hoods. Spills of material (pellets or fuel rods) onto the floor. Loading ADU Pellets And Welding ADU Fuel Rods Controls Safety Significant Controls ~ Passive Engineered Controls (PEC) Passive engineered controls are described in License SNM-1107 and in Procedure RA-108. The requirements for functiona' verification are determined by this evaluation. a) The pellet tray, the cookie theets, conveyor, and the walking beams are PEC and effectively keep all pellets atul fuel rods in a one high planar array. IE-1. The walking beams are PEC to the extent that they process fuel rods in a one-high planar array, Periodic verification is not i required because of configuration control and training, b) [IE-2 deleted] c) The roof, overhead pipes, etc., provide integrity to prevent sources of moderator. IE-3. These 1 are typical potential sources of moderator. Moderator includes water (including fire suppression sprays or mists), plastics, oils, cloth, paper, people, etc. Periodic verification is gg required because leaks and other nxxierators are readily observable during normal operations. Active Engineered Controls (AEC) - None Active engineered controls are defined in License SNM-1107 and in Procedure RA-108. Administrative Controls with Computer a:xl/or alarm assist - None Administrative Controls (AC) i I InitialIssue Date: _ 31 JUL 98 Page No. 5 I Revision Date: Revision No. _0_ _____________m_._

Administrative controls are required operator actions that occur per procedure or training and work I practice. Such actions may require documentation via Control Form or other record. I a)' Pellets are loaded onto trays by automated equipment (before being transported to the fuel rod loading area). IE-4. Periodic, continuous verification is required by operators and supervisors. . b) [IE-5 deleted] { c) Fire suppression water will be applied in limited quantities and as low density mist or spray. j IE-7. Periodic training of fire safety personnel is required on use of fire suppression water. Margin of Safety The margin of safety is not only adequate, but also quite large, because the Bounding Conditions .are much more reactive than conditions expected for normal, and expected or credible upset conditions. Calculations in the referenced evaluations assume optimum moderation and full water reflection. The calculations indicate that kafor the normal and expected upset conditions will not exceed 0.95. No credible upset will cause k, to > 1.0. The parameters that affect neutron multiplication for UO2 Pellets / fuel rods are geometry and moderation. The referenced calculations assumed optimum moderation and full water reflection. Because moderation / reflection could be present in upset conditions, geometry controls are imposed on the stack height for trays of pellets and for planar arrays of rods. Criticality is unlikely (not credible) because no initiating events have been identified that could violate the geometry controls ht the same time that moderator could be added in significant quantities. Double contingency is provided by controlling moderation and the safe slab or safe volume limits via engineered controls. No single credible initiating event leads to criticality. I Summary OfInitiating Events Which Imad To Credible Process Upsets No credible initiating events have been identified for ADU fuel rod loading and end plug welding l that could lead to a criticality (km = 1.0). For moderation control, the plane of the safe slab is well above the floor so that flooding is not I credible. Accidental (roof leaks) or deliberate (fire suppression) sources of moderator would be low density materials so that optimum moderation is not credible. For geometry control, credible . process upsets would not violate the safe slab limit. The safe volume control on stack pellets and scrap pellets is subject to configuration control. Dropped pellets, if any, will assume a safe slab I configuration. i InitialIssue Date: 31 JUL 98 Page No. 6 Revision Date: Revision No.,_0 I

The fault trees in Figure 6.3-1 (pellets) and Figure 6.3-2 (fuel rods) consider certain potential initiating events, none of which lead to criticality. These initiating events are discussed herein to demonstrate that they are not credible initiating events leading to criticality. ] i IE-1. The pellet tray, cookie sheets, conveyor, and the walking beams are designed to hold e pellets or fuel rods in a one-high array. No sides are in place to minimize stacking. Channels have sides that assist the operator in limiting the stacking of fuel rods to a favorable height. IE-2. The floor under the loading table is a passive engineered control. Only a few pellets are expected to fall to the floor. The floor is not designed to be used as a container, but the few pellets that might fall to the floor will disperse into a safe slab. Note: IE-2 was deleted from the fault tree because spills onto the floor are outside the scope of this evaluation. IE-3. The roof, overhead pipes, etc., provide integrity to prevent sources moderator. Even if the integrity were lost, the moderator would affect only a small portion of an intmite slab. The slabs do not have the capability to hold a large quantity of liquid moderator so that the moderating effect of inadvertent moderator would be small.

• IE-4. Controls described in procedures for transport, storage, and use of stack adjustment pellets, and for scrap pellets, trays, channels, and fuel rods are AC. The quantity of pellets used for this function is quite small. The single fixed container for these pellets nuke any initiating event not credible.

IE-5. Controls described in procedures to prevent large nonfavorable geometry containers in the area. Such containers do not maintain safe slab geometry and potentially could collect moderators. It would take more than one initiating event to lead to criticality, e.g., unauthorized container, placement of pellets in such container, addition of moderator from unknown source. Movable NFG containers are not permitted in the area per COP-843002 and sketch 843002-3. Note: IE-5 was deleted from the fault tree because it is outside the scope of this evaluation.

• IE-6. Controls described in procedures to prevent large quantities of process liquids (oils, solvents, mop water, etc.) in the area.

IE-7. Fire suppression water, if needed, will be applied as a mist or spray. The volume of water and the area of application will be small so that any moderating effect will be quite limited. IE-8. Housekeeping is a process to ensure room to transport material with proper spacing between units, to minimize combustibles so that fire suppression water is not needed, and to recover randomly dropped pellets from the floor. l l Common Mode Failure No common mode failure potential has been identified for this evaluation. [ Initial Issue Date: 31 JUL 98 Page No. 7 Revision Date: Revision No. _0

i-l l Summary Tables - See Tables 5.1-1, 5.1-2, and 5.1-3. QC inspection Area Controls Safety Significant Controls Passive Engineered Controls (PEC) Passive engineered controls are described in - License SNM-1107 and in Procedure RA-108. The requirements for functional verification are determined by this evaluation. a) The cookie sheets, conveyor, and the walking beams are PEC. IE-1. The walking beams are PEC to the extent that they process fuel rods in a one-high planar array. Periodic verification is g required because of configuration control and training, and because of continuous surveillance during operation. b) The roof, overhead pipes, etc., provide integrity to prevent sources of moderator. IE-3. Periodic verification is not required because leaks and other moderators' are readily observable during normal operations. c) The storage rack for test / calibration fuel rods is PEC. IE-10. Periodic verification is no_t needed. The aluminum tubes are bundled into fixed arrays. Active Engineered Controls (AEC) - None Active engineered controls are defined in License SNM-1107 and in Procedure RA-108. Administrative controls with Computer and/or Alarm Assist - None Administrative Ccotrols (AC) Safety significant administrative controls are required operator actions that occur per procedure or training and work practice. Such actions may require documentation via Control Form or other

record, a) Controls described in procedures for handling individual test fuel rods, fuel rods in channels, and production fuel rods are AC.

IE-4. General supervision and refresher training are sufficient. Therefore periodic verification is g required. b) [IE-5 deleted] c) Fire suppression water will be applied in limited quantities and as low density mist or spray. IE-7. Periodic training of fire safety personnel is required on use of fire suppression water. Initial Issue Date: 31 JUL 98 Page No. 8 Revision Date: Revision No. _0

Marain Of safety The margin of safety is not only adequate, but also quite large, because the Bounding Conditions are much more reactive than conditions expected for normal, and expected or credible upset conditions. Calculations in the referenced evaluations assume optimum moderation and full water reflection. - The calculations indicate that k for the normal and expected upset conditions will not exceed 0.95. No credible upset will cause k, to > 1.0. The parameters that affect neutron multiplication for UO fuel rods in process are geometry and 2 moderation. The referenced calculations for fuel rods in process assumed optimum moderation and full water reflection. Because moderation / reflection could be present during upset conditions, geometry controls are imposed on the stack height for planar arrays of fuel rods. The parameters that affect neutron multiplication for test / calibration fuel rods in storage are mass (limit on number of rods) and moderation. The referenced calculations assumed full moderation for 1-inch center-to-center rod spacing and partial reflection. Because moderation could be present for upset conditions, mass control is imposed for storage of test / calibration fuel rods. I Criticality is unlikely (not credible) because no initiating events have been identified that could violate the geometry controls at the same time that moderator could be added in significant I quantities.- Double contingency is provided by controlling moderation, and the safe slab and storage rack limits and engineered controls. No single credible initiating event leads to criticality. Summary OfInitiating Events Which I2ad To Credible Process Upsets No credible initiating events have been identified for QC inspection that could lead to a criticality (k, = 1.0). For moderation control, the plane of the safe slab is well above the floor so that flooding is not credible. Accidental (roof leaks) or deliberate (fire suppression) sources of moderator would be low density materials so that optimum moderation is not credible. For geometry control, credible process upsets would not violate the safe slab limit. The fault tree in Figure 6.3-2 (Fuel Rods)' considers certain potential initiating events, none of which lead to criticality. These initiating events are discussed herein to demonstrate that they are j not credibh initiating events leading to criticality. IE-1. The cookie sheets, conveyor, and the walking beams are designed to hold fuel rods in a l one-high array. No sides are in place to minimize stacking. Channels have sides that assist the operator in limiting the stacking of rods to a favorable height. [IE-2 not applicable] InitialIssue Date: 31 JUL 98 Page No. 9 Revision Date: Revision No. _0 1

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IE-3. The roof, overhead pipes, etc., provide integrity to prevent sources of moderator. Even o if the integrity were lost, the moderator would affect only a small portion of an infinite slab. The slabs do not have the capability to hold a large quantity of liquid moderator so that the moderating effect of inadvertent moderator would be small. i IE-4. Controls described in procedures for handling fuel rod channels and individual fuel rods e are AC. The potential consequences of operator error would be small because of the engineered controls that are in place. I l IE-5. Controls described in procedures for limiting nonfavorable geometry containers are AC. e - The potential consequences of operator error would be small because of the administrative controls on moderators and containers that are in place. Movable NFG containers are not permitted in the area per COP-843002 and sketch 843002-3. Note: IE-5 was deleted from the - fault tree because it is outside the scope of this evaluation. IE-6 Controls described in procedures for limiting process solutions (oils, solvents, mop i water, etc.,) are AC. The potential consequences of operator error would be small because of the administrative controls on moderators and containers that are in place. IE-7. Controls described in procedures for limiting fire suppression water to mists or sprays are AC. The potential consequences of error would be small because of the administrative controls fire suppression effects would be localized and would involve low density water. .IE-8. Housekeeping is a process to ensure room to transport material with proper spacing between units and to minimize combustibles so that fire suppression water is not needed. IE-9. Not applicable to this area. IE-10. The storage racks space the test / calibration fuel rods as well as control the overall configuration and number of fuel rods. The racks are open at both ends so that optimum interstitial moderation is not feasible. Common Mode Failure No common mode failure potential has been identified for this evaluation. Summary Tables - See Tables 5.1-2 and 5.1-3. 1 i ADU Fuel Rod Scrap / Rework Area Controls Initial Issue Date: 31 JUL 98 Page No. 10 Revision Date: Revision No. _0 L_

-} ) j Safety Significant Controls t ~ Passive Engineered Controls (PEC) Passive engineered controls are described in License SNM-1107 and in Procedure RA-108. The requirements for functional verification are determined by this evaluation. a) The fuel rod channels are PEC. IE-1. Periodic verification is no.t required becarse of configuration control and training, b). The roof, overhead pipes, etc., provide integrity to prevent sources of moderator. IE-3. Periodic verification is r!o_t required because' leaks and other moderators are readily observable during normal operations. c)- The storage racks for scrap / rework fuel rods are PEC. IE-9. Periodic verification is not needed. Active Engineered Controls (AEC) - None Active engineered controls are defined in License SNM-1107 and in Procedure RA-108. Administrative Controls with Computer and/or Alarm Assist - None Administrative Controls (AC) Safety significant administrative controls are operator-required actions that occur per procedure or training and work practice. Such actions may require documentation via Control Form or other

record, a) Controls described in procedures for handling individual test fuel rods, fuel rods in channels, and production fuel rods are AC.

IE-4. Continuous, periodic verification by supervision is i needed. I b) [IE-5 deleted] c) Fire suppression water will be applied in limited quantities and as low density mist or spray. IE-7. Periodic training of fire safety personnel is required on use of fire suppression water. Margin of Safety The margin of safety is adequate, and also quite large, because the Bounding Conditions are much more reactive than conditions expected for normal, and expected or credible upset conditions. . Calculations in the referenced evaluations assume full interstitial moderation and full water reflection. The calculations indicate that k,,for the normal and expected upset conditions will not exceed 0.95. No credible upset will cause k,, to > 1.0. The parameters that affect neutron multiplication for UO fuel rods are geometry and moderation. 2 The calculations assumed optimum moderation and full water reflection. Because moderation and Initial Issue Date: 31 JUL 98 Page No. 11 Revision Date: Revision No. _0 l I f i 1 l

reflection could be present during upset conditions, geometry controls are imposed on the stack i height for fuel rods on fuel rod carriers. f Criticality is unlikely (not credible) because no initiating events have been identified that could violate the geometry controls at the same time that moderator could be added in significant quantities. Double contingency is provided by controlling moderation and the safe slab limits (engineered controls). No single credible initiating event leads to criticality. Summary Of Initiating Events that Imad to Credible Process Upsets There were no credible initiating events identified with ADU fuel rod scrap / rework that could lead l to a criticality (k,, = 1.0) i l For moderation control, the plane of the safe slab is well above the floor so that flooding is not j credible. Accidental (roof leaks) or deliberate (fire suppression) sources of moderator would be low density materials so that optimum moderation is not credible. For geometry cantrol, credible J process upsets would not violate the safe slab limit. ] 1 The fault tree in Figure 6.3-2 ( ) Fuel Rods) considers certain potential initiating events, none of which lead to criticality. These l initiating events are discussed herein to demonstrate that they are not credible initiating events leading to criticality. l IE-1. The cookie sheets, conveyor, and the walking beams are designed to hold fuel rods in a one-high array. No sides are in place to minimize stacking. Channels have sides that assist 1 L the operator in limiting the stacking of fuel rods to a favorable height. IE-2 not applicable to this area. l IE-3. The roof, overhead pipes, etc., provide integrity to prevent sources moderator. Even if e the integrity were lost, the moderator would affect only a small portion of an infinite slab. The slabs do not have the capability to hold a large quantity of liquid moderator so that the moderating effect ofinadvertent moderator would be small. IE-4. Controls described in procedures for handling fuel rod channels and individual fuel rods j are AC. The potential consequences of operator error would be small because of the j engineered controls that are in place. l ' IE-5. Configuration control prevents the existence of any container large enough to hold e fuel rods and liquids. Note: IE-5 was deleted from the fault tree because it is outside the scope of this evaluation. Initial Issue Date: 31 JUL 98 Page No. 12 Revision Date: Revision No. _0

IE-6. Controls described in procedures for limiting process solutions (oils, solventr, mop o water, etc..) are AC. The potential consequences of operator error would be small because of the administrative controls on moderators and containers that are in place. IE-7. Controls described in procedures for limiting fire suppression water to mists or sprays are AC. The potential consequences of error would be small because of the administrative controls fire suppression effects would be localized and would involve low density water. IE-8. Housekeeping is a process to ensure room to transport material with proper spacing between units and to minimize combustibles so that fire suppression water is not needed. . IE-9. The QC storage racks for test / calibration fuel rods are subject to configuration control as well as being limited in number so that criticality is not possible given the incredible circumstances of optimal interstitial moderation and full reflection. Common Mode Failure No common mode failure potential has been identified for this evaluation. hmmary Tables - See Tables 5.3-2 and 5.3-3. l l I l I l i l \\ i Initial Issue Date: 31 JUL 98 Page No. 13 Revision Date: Revision No. _0 _.__..__._.__._____.___._.______o

l i l l Table 5.3-1 for Pellets

SUMMARY

OF DEFENSES PROVIDED AGAINST A SINGL E FAILURE Defense Set 1 Defense Set 2 General Descriptor Prevent Regulate Detect / Prevent Regulate Detect React ' L Q yg};1 % g.;,< ,L'; M.. '@ a- 'M,, ' ?y 9 3.m sg ' <, 1 c,;

%V M.

y: n:o .py ' u aw -qp ql-y. 7 > n.7

s. y t>

,n Fuel Rods Exceeding 4.5" Slab 1 4 8 Moderator Contingency Thickness @ @, 4, M y 4 - J [J hp a.J:<'/gl,,.[ ,l,' ., f 1{,l ', n > ;,p #1 <'9? n 4 s

hpy, s, _ ;

1 yS W '.;gg 5;g E, lF W r 91 M a n,, ' fy

v" 4

4 Geonietry Contingency Full Interstitial Moderation 3, 5 6,7 i l l 1 Initial Issue Date: 31 JUL 98 Page No. 14 Revision Date: Revision No. _0

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Table 5.3-2 for ADU Rods 4

SUMMARY

OF DEFENSES PROVIDED AGAINST A SINGLE FAILURE Defense Set 1 Defense Set 2 Prevent Regulate Detect / Prevent Regulate Detect I React c wn -{ j' 4.- .... w. l(:1;

}

7 q_ i)k N s j .s t , y;z a y. Fuel Rods Exceeding 4.5" Slab Thickness 1,9,10' 4 8 Moderator Contingency m m,, q:, 3.- g y,,, :4,, 3' ',. Modermer Castingency... + s. 4 vl;:.l, - *,& m s ,s ' Geometry Contingency FullInterstitial Moderation 3 6,7

• This is actually mass (number of rods) control for test / calibration rods.

Defenses No. 2 & 5 not used in this Table. i l \\ Initial Issue Date: 31 JUL 98 Page No. 15 Revision Date: Revision No. _0 1 1 IL____________.____...._..___...

Table 5.3-3 CRITICALITY SAFETY LIMITS FOR Km = 0.90,0.95, AND DELAYED CRITICAL PARAMETER 9 iNORMAL:; BOUNDING

CRITICALITY

' CRITICALITY CRITICALITY: LOPERATING '. ASSUMPI10Nj-SAFETY . SAFETY LIMIT r CONDITIONSe - LIMIT, LIMIT-

Delayed Critical'.

's 0.90- ' s 0.95 ' ' Optimum 2"U MASS

• Dry (Full Interstitial 15x15 17x17 18x18 (NO. OF RODS)

Moderation) MODERATOR / Dry Optimum Optimum Optimum Optimum CONCENTRATION One Pellet High, ~ GEOMETRY ** One Rod High, Two Pellets N/A 4-inch Slab 4.5-inch Slab or 4-inch / Rods High Channel VOLUME 1.5 Liter N/A N/A N/A 16 Liters Pellet Container DENSITY / FORM Heterogeneous Heterogeneous Heterogeneous Heterogeneous Heterogeneous UO, UO, UO, UO, UO, ABSORBERS N/A N/A N/A N/A N/A ENRICHMENT s 5.0 wt. % s 5.0 wt % s 5.0 wt. % s 5.0 wt. % s 5.0 wt. % REFLECTION Partial Water Full Water Full Water Full Water Full Water (1 inch) (12 inches) (12 inches) (12 inches) (12 inches) Mass limit (number of rods) applicable only to storage of test / calibration fuel rods in 1" spaced aluminum holes.

• • Geometry of QC test / calibration fuel rod storage exceeds 4-inch limit; subject to mass control (number of fuel rods).

Initial Issue Date: 31 JUL 98 Page No. 16 l Revision Date: Revision No. _0

FIGURE 6,3-1 FAULT TREE ADU ROD MANUFACTURING AREA (PELLETS) SUFFICIENT HEIGHT OF UO2 PELLETS AND VOLUME OF MODERATOR l IE-1 IE-4 IF.a F SMICONTROL PELLETS ACCUMULATE TO >4.5" DEPTH BY FAILURE OF 0000 HOUSEKEEPING k TRAINING & TRMNING & NO WORK PRACTICE l NOTE 2 IE 3 IE-6 IE-7 SMICONTROL FULL INTERSTITIAL MODERATION FROM FAILURE OF CONTROLS ON SOLUTIONS ( (OILS, SOLVENTS, MOP l WATER, ETC.) l 6 o E l MOP-750353 NOTES: l

1) lE-2 ANO DE-5 DELETED.

2) TRMNING AND WORK PRACTICE LIMITS TRAYS TO 1.HIGH.

3) TRAINING AND WORK PRACTICE DO NOT PERMfT STACKING PELLETS ON TRAYS. IT WAS JUDGED NOT CREDIBLE FOR TRAYS TO BE TRANSPORTED TO THE ROD LOADING AREA WITH PELLET DEPTHS APPROACHING 4.5".

i 1 i HO CIDAMON MODE FAILURE IDENTIFIED FOR MODERATOR AND LOSS OF GEOMETRY CONTROL, l f Initial Issue Date: 31 JUL 98 Page No. 17 Revision Date: Revision No. 0 l l l

FIGURE 6.3-2 FAULT TREE ADU ROD MANUFACTURING AREA (RODS) 9 4 I l"';,26 E i i IE.1 IE 4 IE4 l l IE-9 ROD $ M T TO N.5" E EPt PRACT L a o COP.750353 MOP-750353 IE 3 IF4 IE.7 MOOE OM F LURE = = =~- WATER. ETC.) L A o E MOP-750353 EP B-01 NOTES: !!lM " = " *' 'NO COMMON MODE FAILURE IDENTIFIED FOR MODERATOR AND LOSS OF GEOMETRY CONTROL. Initial Issue Date: 31 JUL 98 Page No. 18 Revision Date: Revision No. _0

l Chemic:t Sallety cnd Fire Safety Centrola To be provided in a future Integrated Safety assessment. l InitialIssue Date: 31 JUL 98 Page No. 19 Revision Date: Revision No. 0 l: L__ _}}