ML20248G847

Application for Rev to Certificate of Compliance 7001, Revising Technical Safety Requirement Limiting Condition for Operation 2.6.4.1, Criticality Accident Alarm Sys

ML20248G847
Person / Time
Site:	Paducah Gaseous Diffusion Plant
Issue date:	05/27/1998
From:	John Miller UNITED STATES ENRICHMENT CORP. (USEC)
To:	Paperiello C NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
References
GDP-98-0105, GDP-98-105, NUDOCS 9806050362
Download: ML20248G847 (55)

Text

{{#Wiki_filter:\\ eP ,fol I,,USEC A Glotud Ener,c *empany JAuss H. MIU.ER Dir: (301) 564-3309 VICE PRESIDENT, PRODUCTION Fax:(301) 571-8279 ) l I May 27,1998 GDP 98-0105 \\ Dr. Carl J. Paperiello Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission ) Washington, D.C. 20555-0001 Paducah Gaseous Diffusion Plant (PGDP) Docket No. 70-7001 Certificate Amendment Request - Criticality Accident Alarm System Clusters in C-710 and C-720 l l

Dear Dr. Paperiello:

In accordance with 10 CFR Part 76.45, the United States Enrichment Corporation (USEC or Corporation) hereby submits a request for amendment to tlie certificate of compliance for the Paducah, Kentucky Gaseous Diffusion Plant. This certificate amendment request revises Technical Safety Requirement (TSR) Limiting Condition for Operation (LCO) 2.6.4.1, Criticality Accident Alarm System. - The Plan for Acideving Compliance with NRC Regulations at the Paducah Gaseous Diffusion Plant (Compliance Plan), Issue 8, states that " permanent criticality accident alarm detector clusters will be installed, relocated, and/or reconditioned in building C-710 to replace the l existing portable detectors in building C-710 by June 30,1998." As a consequence of this modification, the TSRs should be modified to reflect the addition of the new, permanent clusters l in building C-710. Tnis Certificate Amendment Request provides a revised TSR 2.6.4.1 to l reflect the addition of these new detectors in C-710. In addition, TSR 2.6.4.1 has been revised to l update the Building /FMW, Numbers associated with CAAS cluster "AL." ~ Buildings C-720M, C-720K, C-720R, and C-720S do not contain fissile material, nor are fissile material operations conducted, within these buildings. As such, these facility numbers have been deleted from TSR l 2.6.4.1. 9806050362 980527 PDR ADOCK 07007001 Fvpb C PD9 1 I 1 ~ 6903 Rockledge Drive. Bethesda, MD 20817-1818 Telephone 301564-3200 Fax 301564@01 http://www.usec.com Omces in Uvermore, CA Paducah KY Portsmouth. OH Washington, Dc 01 M i

l Dr. Carl J. Paperiello May 27,1998 GDP 98-0105, Page 2 to this letter provides a detailed description and justification for the proposed changes. Enclosure 3 contains the revised Application TSR and Safety Analysis Report (SAR) pages associated with this request. The TSR pages are provided for your review and approval. The SAR pages have been evaluated in accordance with 10 CFR 76.68. Based on the results of the 10 CFR 76.68 evaluation, the enclosed SAR pages do not require prior NRC review and approval and are provided for information only. Enclosure 4 contains the basis for USEC's determination that the proposed changes associated with this certificate amendment request are not significant. The changes proposed in this Certificate Amendment Request also affect TSR 2.4.3.3, Criticality Accident Alarm Systems, presented in the SAR Update Certificate Amendment Request (USEC letter GDP 97-0188, James H. Miller to Dr. Carl J. Paperiello, " Certificate Amendment Request-Update the Application Safety Analysis Report," dated October 31,1997). The changes to the SAR Update Certificate Amendment Request are included in Enclosure 3. 1 Although TSR 2.6.4.1 is being revised to reflect the modifications required to implement i Compliance Plan, Issue 8, which is required to be completed by June 30,1998, this TSR change I is not required to support completion of the Plan of Action and Schedule associated with this Compliance Plan Issue. However, to allow plant operations to benefit from the enhancements to the CAAS for C-710 and C-720, USEC requests NRC review and approval of this Certificate Amendment Request as soon as possible. The amt:ndment should become effective 15 days from issuance. . Any questions related to this subject should be directed to Mark Smith at (301) 564-3244. There are no new commitments contained within this submittal. Sincerely, es H. Miller Vice President, Production L 'l l

Dr. Carl J. Paperiello May 27,1998 GDP 98-0105, Page 3

Enclosures:

1. Affidavit 2. United States Enrichment Corporation, Proposed Certificate Amendment Rquest, Criticality Accident Alarm System Clusters in C-710 and C-720, Detailed Description of Change 3. Proposed Certificate Amendment Request, Paducah Gaseous Diffusion Plant, Lettx GDP 98-0105, Removal / Insertion Instructions 4. United States Enrichment Corporation, Proposed Certificate Amendment Request, Criticality Accident Alarm System Clusters in C-710 and C-720, l Significance Determination cc: Mr. Robert C. Pierson, NRC NRC Region III Office NRC Resident Inspector-PGDP 1 NRC Resident Inspector-PORTS Mr. Randall M. DeVault, DOE

l OATH AND AFFIRMATION I I, James H. Miller, swear and affirm that I am Vice President, Production, of the United States Emichment Corpora: ion (USEC), that I am authorized by USEC to sign and file with the Nuclear Regulamry Commission this Certificate Amendment Request for the Paducah Gaseous i Diffusion Plant, addressing revisions to the Criticality Accident Alarm System Technical Safety Requirements as contained in USEC Letter GDP 98-0105, that I am familiar with the contents thereof, and that the statements made and matters set forth therein are true and correct to the best j of my knowledge, information, wid belief. 'l 1 James H. Miller On this 27th day of May,1998, the officer signing above personally appeared before me, is known by me to be the person whose came is subscribed to within the instrument, and acknowledged that he executed the same for the purposes therein contained. In witness hereofI hereunto set my hand and official seal. A A A A L},m __ L/aurie M. Knisley, Notary Public// l State of Maryland, Montgomery County L My commission exp. ires March 1,2002 l E___________._________._

1 \\ l GDP 98-0105 Page 1 of 3 United States Enrichment Corporation (USEC) Proposed Certificate Amendment Request Criticality Accident Alarm System Clusters in C-710 and C-720 Detailed Description of Change A. TSR LCO 2.6.4.1 and the basis statement for TSR 2.6.4.1 are being revised to change the cluster designations for building C -710 to reflect the new permanent CAAS configuration j for building C-710. The Plan for Achieving Compliance with NRC Regulations at the Paducah Geseous Diffusion Plant (Compliance Plan), Issue 8, states that " permanent criticality accident alarm detector clusters will be installed, relocated, and/or reconditioned in building C-710 to replace the existing portable detectors in building C-710 by June 30,1998." Based on an evah:ation performed in support of thi:: Compliance Plan action, the new CAAS for the C-710 Laboratory will have five permanently installed aamma radiation detection cluster units instead of the existing configuration of one portabic and two permanent cluster units. Use of five permanent clusters will provide overlapping CAAS coverage for the majority of C-710. Since, the cluster designations for building C-710 currently listed in TSR 2.6.4.1 are different than the cluster designations for the new, permanent CAAS in building C-710, TSR 2.6.4.1. including the basis, will be revised to reflect these new cluster designations. To determine the optimal location for the new CAAS cLWers, an evaluation was performed which demonstrated that five new detectors located on the first floor of building C-710 provide adequate CAAS coverage for the facility. A summary of this evaluation is provided below The detailed evaluation is available at the site for review. The point kemel methodology was utilized to determine the CAAS detector range of coverage. This methodology, which considered both neutron and photon transport, utilized the following assumptions: 1. The dose rate of a minimum criticality accident of concem at 2 meters from the source is 20 rad / min. l 2. The sustained fission reaction is moderated an unreflected. This assumption j yields conservr.tive results since CAAS detectors are less sensitive to this type of criticality accident than fast transients and unmoderated configurations. l 3. . The dose rate required to trip the criticality accident alarm is 10 mrem /hr. 4. The neutron to gamma dose ratio in air for moderated systems is 0.11 f 5. An air transmission factor of 1/3 is assumed at large distances. Utilizing these assumptions and the photon-neutron point kernel methodology, the maximum l l 1 ) !l. l L_ _______________________________d

GDP 98-0105 Page 2 of 3 United States Enrichment Corporation (USEC) Proposed Certificate Amendment Request Criticality Accident Alarm System Clusters in C-710 and C-720 Detailed Description of Change allowable shielding material thickness between the source and the detector which would yield a dose attenuation of 10 mrem /hr was calculated. This calculated allowable shielding material thickness was then compared to the C-710 building layout and materials of construction to determine the placement of the detector clusters. The clusters were located within the facility such that the shielding material between the detector and the assumed location of a criticality was less than the maximum allowable shielding material thickness calculated using the point kemel methodology. Based on the results of the comparison of the building layout and materials of construction to the allowable shielding material thickness, building C-710 requires five permanent CAAS clusters to provide adequate CAAS coverage for the facility. The five permanent CAAS clusters will be placed on the first floor and positioned approximately as follows: (1) 60 feet from the north end of the north-south wing, (2) 140 feet from the north end of the north-south wing, (3) 140 feet from the east end of the east-west wing, (4) 140 feet from the east end of the east-west wing, and (5) within the NDA laboratory. I The basis was also changed to reflect the new CAAS design. The phrase "a local hom i associated with each individual cluster and" was deleted and new text was added to the end of the same sentence to reflect that the new C-710 CAAS utilizes electronic horns in a set of two separate and independent networks, each capable of providing sufficient audibility levels required for evacuation. This is a different configuration from the old CAAS for this building which utilized air homs on the local clusters as well as the building alarms. The new language reflects that the other building covered by this TSR still utilize the previous design. The network will include a total of approximately 290 horns incide and outside C-709 and C-710. Each network ensures the required audibility levels are provided throughout the building, on the roof and grounds around the building, and for those buildings within the CAAS evacuation zone. I.astly, the phrase " local Guster to sound" was changed to read j " local cluster hom to sound (where applicable)" to clarify that the local hom associated with CAAS clusters provides the audible signal (not the cluster itself) and to acknowledge that some of the clusters (i.e., the new clusters in C-710) do not have local homs. l I B. TSR LCO 2.6.4.1 is being updated to correct the Building / Facility Numbers associated with Cluster "AL." Buildings C-720, C-728, and C-720C have areas, equipment, or processes which could contain greater than 700 grams of 2"U en-iched to 21.0 wt %. However, C-720M (Field Instrument Trailer), C-720K (Instrument shop addition), C-720R (Instrument Repair Trailer), and C-720S (Respirator Repair Facility) do not contain fissile material, nor i I l i 1

GDP 98-0105 Page 3 of 3 United States Enrichment Corporation (USEC) Proposed Certificate Amendment Request Criticality Accident Alarm System Clusters in C-710 and C-720 Detailed Description of Change are fissile operations aliewed in these facilities per procedures which implement Nuclear Criticality Safety Approval (NCSA) requireraents. Also, building C-720M, C-720K, C-I 720R, and C-720S were removed from the basis of the TSR since there is no fissile operation that is conducted in these facilities and therefore do nct have criticality accident alarm systema. The movement of fissile material is comrolled by NCSA to ensure that quartities of fissile meterial are only handled and stored in areas that have operable CAAS, except where specifically justified by analysis. (Audibility requirements do apply since they are within the possible 12 rad exposure radius of nearby facilities that do conduct operations with fissile material.) 1 i l

GDP 98-0105 42 Pages Proposed Certificate Amendment Request Paducah Gaseous Diffusion Plant Letter GDP98-0105 Repinval/lneertinn Inatruetions Remove Page Insert Page Volume 1 Section 3.12 Section 3.12 Page 3.12-3/4, 3. [2-5/6, 3.12-7/8 Page 3.12-3/4, 3.12-5/6, 3.12-7/8 Section 3.15 Section 3.15 Page 3.15-37/38,3.15-39/40 Page 3.15-37/38. 3.1S-39/40 Volume 2 Appendix A Appendix A Page 2-5/6,2-9/10,2-13/14,2-15/16,2-Page 2-5/6, 2-9/10, 2 13/14, 2-15/16, 2-17/18,2-19/20,2-21/22,2-23/24,2-41/42,2-17/18,2-19/20,2-21/22,2-23/24,2-41/42,2-47/48,2-51/52,2-52a/52b 47/48,2-51/52,2-52a/52b Volume 4 Section 2.6 Section 2.6 Pages 2.6-3, 2.6-5, 2.6-7, 2.6-8 Page 2.6-3,2.6-5,2_6-7,2.6-8 _ Volume 5 Section 3.15 Section 3.15 Table 3.15-2 Page 12, Table 3.15-2 Page 13 Table 3.15-2 Page 12, Table 3.15-2 Page 13 TSR Section 2.4 TSR Section 2.4 lages 2.4-9 and 2.4-12 Pages 2.4-9 and 2.4-12 i l l l 1

. SAR-PGDP January 19,1996 Rev. 2 3.12.2.5 F ,,_y Comannication Systen Personnei i:xvolved in the handhng of plant emergencies use radio units with individual or combined access to the operations, maintenance, or security repeater networks. Key supervisory personnel, such as the shift supermrandent, have access to radio units that operate on the three networks. Most emergency vehicles are equipped with security and operations network radio units since both networks are used during emergency situations. A single side band (SSB) radio is provuled for emergency comnnmication with DOE-Oak Ridge Operations (ORO), and nnners are available to monnor local law enforcement networks. Radios permit emergency comnumication with the Kentucky State Police. Tac 1 Ant is also a station point for NAWAS (Federal Emergency Management Agency's National Warning System). Telephones along with other necesary equipment for NAWAS are located in the C-200 and C-300 buildings. 3.12.3 Pnblic Address System The plant utilizes two public address systems which provide voice communication. One of these is the Process Public Address System, which prunarily serves the enrichment facilities, while the other system, Evacuation Public Address System. serves the entire plant. - All paging is initiated from the C-300 CCF and the C-200 Control Center and is distributed by the transmission of sudio and control voltage through underground cable. The C-200 system is a slave to the C-300 master control. These voltages are distributed to cach building where they supply signals to drive a building amplifier and associated speakers. Some buildings have individual local public address systems with supervisory override from C-300. The C-720 building has four different local systems while the C-200, C-340, C-400, and C-410/420 buildings all have local systems. 3.12.4 Data Ca====le=*Ia== Several miscellaneous telecommunications systems are in use throughout the plant. These systems are operated for the transmission or reception of signals, writings, images, or sounds. These include systems such as facsimile transrmssion devices, data communications devices, cryptographic devices, the virtual address extend (VAX) system, intercom systems, and programmable calculators (to be used as 1 computer termmals via telephone circuits). In addition to these methods of data communication previously mentioned, a vacuum tube system is urdirad between the ACR and their power supplying switchyard to provide rapid transport of permits. The C-720 building also uses one of these systems between the stores and work order area. l l I l 4 3.12-3 I l t.

4 SAR-PGDP May 27,1998 RAC 97C240 (RO) 3.12.5 ' Plant and Bunding Evacuation Alarm System The plant utilizes horns and an evacuation public address system to signal a "take cover" warnmg or the necessity of a plant evacuation. 'Ihese signals are audible throughout most of the plant. In areas where they are not audible, (such as the process buildings), howlers are utilized to signal personnel of the existence of a plant or building emergency. 3.12.6 Criticality Accid =t Alann Systen 'Ihe criticality accident alarm system (CAAS) is designed to detect gamma radiation levels that would result from the minimum criticality accident of concern and to activate the building evacuation alarms and alanns in the Central Control Facility (CCF). The system consists of radiation instrument assemblies. An mstrument assembly consists of three individual instruments connected so that an alarm state on two of the three instruments in an assembly will cause a radiation alarm. The radiation assembly is referred to as a " cluster" while any one of the three instruments which compose the cluster is designated a " detector module." The radiation alarms do not prevent a criticality. 'Ihey do, however, mitigate the consequences to personnel in the immediate area by providing audible alarms which will warn personnel to evacuate the area immediately and prevent reentry into the area until an all-clear is given by the incident commander. ) The clusters are installed in buildings containing special nuclear material except where a criticality safety analysis has been performed that demonstrates that a criticality could not occur. There are a total of 35 permanent clusters. Criteria for when these detector modules are required are established by the l Nuclear Criticality Safety Section. Requirements as specified in American National Standards Institute standard ANSI /ANS-8.3 were used to determine the surveillance practices. Current cluster locations are listed in Table 3.12-1. Figure 3.12-1 shows a simplified schematic of the horn / beacon control circuit for - air operated alarm horns. 1 Where possible, these detector locations provide for areas of overlapping coverage such that coverage is maintained even when a single cluster unit is unavailable. The TSRs for each facility specify the action required when complete' coverage is lost. These actions may include time requirements for repair of the lost clusters, use of a portable CAAS unit, shutdown of the affected area, or mitigative actions which

reduce the potential for a criticality.

'Ihe portable CAAS units are similar in design and function to the pennanent clusters. In addition to j being used when permanent clusters are inoperable, these portable units may be used in situations where j temporary conditions create the potential for a criticality, such as monitoring fissile waste storage areas. Additionally, the C-720 facility was recently identified as requiring coverage whenever converter ) maintenance is performed and the portable unit will be used if necessary until a permanent cluster is - installed. L A building which does not contain special nuclear material as previously described but would be l i affected by a criticality occurring in an alarmed building is provided with alarms which are slaved to the alarmed building. 3.12-4 y

1 SAR-PGDP May 27,1998 RAC 97C240 (RO) When a cluster goes into alarm, it activates the building evacuation horn, the cluster's plant air or nitrogen evacuation horn (where applicable), the external red beacon lights, and the audible and visual l alarms on th master control console in the CCF, Building C-300. Each cluster is designed to operate independently of the 120 VAC power supply for a minimum of four hours. The clusters consist of three detector modules which alarm when a gamma dose-rate of 10 milliroentgen per hour (mR/hr) above background is detected. Each module has an internally generated I signal to maintain a constant operational check of the detection circuits. This " background" is adjusted to a predetermined value on the front panel meter. Any detected radiation will add to the meter reading. The 10 mR/hr-type instrument consists of three self-contained sodium iodide detector modules, each module is identically calibrated to provide an output at a predetermined radiation dose-rate. The outputs of these modules are connected into a voting logic matrix such that at least two modules, or under some faulted conditions one module, must alarm to give a criticality incident alarm. The circuit of the detector module has been designed to provide instrument sensitivity to a preselected radiation dose-rate delivered within a short period of time, but insensitive to a radiation fie!d below a predetermined threshold value. Therefore, the instrument is capable of detecting a nuclear incident and providing an alarm to those ~ locations which have received significant radiation dosages, but self-adjusts to compensate for minor fluctuations in background. The critical incident detector has been designed to exhibit tl.e highest degree of reliability. The alarm modules do not have external adjustments and cannot be used for quantitative measurements. A feature has been incorporated to provide a trouble alarm on the C-300 radiation alarm - console whenever any of the following occurs: Line power failure

• Module removal Cable separation Loss of nitrogen pressure (where applicable)

Increased or decreased manifold pressure (where applicable) Loss of signal at a detector module Indication of radiation detection by only one detector module When the CAAS goes into alarm, associated building horns (air-powered and electronic) and warning lights external to the building are eergized automatically. Air-powered local horns are supplied by plant air with the exception of the AC and AD clusters in C-746-Q, which are completely nitrogen powered. In the event of a loss of plant air, each local horn has a nitrogen backup system to sound the horns. Nitrogen bottles are replaced when the pressure is less than 900 psig. A standard nitrogen bottle at a pressure of 900 psig will' sound the hom for more than 120 seconds. Some evacuation horns are supplied from plant air and may be turned off from the CCF. Other evacuation horns are electronic (C-709, C-710, C-720, and C-720M). 'Ihe #1,2, and 3 portable l clusters are also electronic. The electronic horns have a self-contained banery backup power supply. The alann instrumentation is' designed to actuate at the 10-milliroentgen level, and provides an alarm indication in the C-300 CCF. Slaved buildings are buildings located within the 12 Rad radius from a CAAS alarmed building or area and that are couipped with a plant air or nitrogen operated horn unit similar to the unit described above, or an electronic evacuation horn that produces a similar sound. Slaved building horns are located in ' Buildings C-709, C-310A, C-420, and C-720-M. Buildmg C-709 is slaved from Building C-710; Building l C-310A is slaved from Building C-310; Building C-420 is slaved from Building C-400; and Building C-720-M is slaved from Building C-409. 3.12-5

I f i SAR-PGDP ~ January 19, 1996 Rev.2 When a cluster emers an alarm 9-C=. the evacuanon and criticality alarm horn units in buildings slaved to that detector module are also activated. l As previously mentioned, the C-300 CCF radiation alarm console panel is designed to give alarm indentions and kranana. The panel displays a map with indic=*ing lights showing the condition of the alarm system. Controls fbr resetting the alarm units, individual buddmg alarm horn lockouts, and devices i for remote emding of the building alarm horns are part of the design. l-If the detector modules are in alarm condition, the 10 mR/hr (red) light illununa:es and a memory light (blue) locks in. After the incident commander has acknowledged the radiation alarm, the detector modules may be reset. Other building evacuation horns may be energized for complete personnel evacuation. The memory light must be reset with a key. 3.12.7 Argon G-j J. Radiation measurement systems consisting of sensitive argon gammagraphs, are also placed at strategic points in the plant. The gammagraph supplies a continuous record of the background gamma radiation and will assist the incident commander in determuung conditions in the area immediately following a criticality incident. The argon gammagraph is a radiation rate measuring instrument which utilizes an ionization chamber to telemeter information continuously to recorders in the ACR and CCF radiation alarm consoles. This instrument will switch automatically in four ranges, and indicate the ranges with colored lights both locally and at the C-300 CCF radiation alarm console. The argon gammagraphs are not Wnrified as a TSR system since they only record a radiation or criticality incident. 3.12.8 References

1. K/PS-1056, First Article Evaluation Testing of the NRC Criticality Alarm Clusters, dated May 1985.

3.12-6

._= 4 \\ SAR-PGDP May 27,1998 f RAC 97C240 (RO) T - 3.12-1. I ?- ::- s of '- '--r '_:-- d= Building Clusters I.ocation l C-310 G. Cell floor, central area, Col. D-Il 'H Ground floor, loading rum, Col. C-IlY C-310A slave Actuated from C-310 C-331 J. Cell floor, Col. H-10 K. Cell flocr, Col. Y-10 L Ground floor, atop surge drum room Col. W-16 C-333 Z, Cell floor, Col. S-9Y AJ Ground floor, Col. MA-22 C-333A AA, I West, Col. MC-50 AB 1 East, Col. N-50 C-335 A, Cell floor, Col. H-10 B, Cell floor, Col. Y-10 C. Ground floor, atop surge drum room Col. X-16 AF Cell Floor, Col. J-21 C-337 T, Cell Floor, Col. T-9Y U, Cell Floor, Col. T-25Y V, Cell Floor, Col. T-41Y W, Cell Floor, Col. G-9Y X, Cell Floor, Col. G-41Y Y, Ground Floor, Col. Ga-27 AK Cell Floor, Col. G-25Y C-337A N Ground Floor, Col. N-51 . C-360 R. Central area, Col. E-3 S South Wall, Col. AB-3 C-400 D, Test loop area, Col. D-10 E Spray booth area, Col. C-4 C-409 P, Decontamination Booth Col. B-9 I AE South Wall, Col. C-8 C-420 slave Act.iated from C-400 C-709 slave Actuated from C-710 C-710 AM lst Floor Hall, Col. L-3 AN ist Floor Hall, Col. G-3 AP Lab Room #80 AQ lst Floor Hall, Col. C-5 AR . Ist Floor Hall, Col. C-8 C-720 AL Ground floor, Col. K-13 C-720-M slave Actuated from C-409 C746-Q AC, Center Wall, West AD Center Wall, East C 310 Argon Gammagraph Cell floor, central area, Col. D-11 Ground floor withdrawal room, Col. F-2 C-331 Argon Gammagraph Cell floor, control area, Col. W-17 C-335 Argon Gammagraph Cell floor, control area, Col. V 18 C-400 Argon Gammagraph Central area. Col. C-7 3.12-7 l L

1 a SAR-PGDP May 19,1998 RAC 97C240 (RO) r - - - - - - -- 10m 10m 10m I DETECTOR DETECTOR DETECTOR I [ CLUSTER UNIT l l CHANNEL CHANNEL CHANEl. i l i I LOGIC WHERE I ALARM I mnix PLANT AIR AP LICABLE L - __ _ _.a LEEND: LOCAL HORN l (L) RADIATION RJEM CEIET CONTROL BOX LOCAL HORN t.___ (RASC) RADIATIm alRH SYSTEM CONS (LE NITROGEN ,DR 120 VAC y*ih ct) - \\ BUILDING s ii i i ii s BEACON 3 '.'BLDGLIGHTSl R Z' RESET' CO E CTION FROM V H l-Y m(h OTER CLUSTER UNITS I \\p 120VAC's i,i BUILDING '8 h0RNS I (RASC) r-b T

h'UT~Clc g

~ llj W HORN l fDR'l I"PERMISSIVESL + 4 8V s' l 20 i sic RRN ' PERM. ON' I l +48v -o W D e l l H I -Y l I M V b y}- - - - - HORU DFFI HORN " PERM. OFF" A SET l C Q'X HORN CONTROL SWITCH NOTE: TITLES SHOWN IN " " ARE LABELS VISIBLE ON THE PANELS OR COMPONENTS Figure 3.121. Simplified schematic of horn / beacon control circuit. l 3.12 8 i

e s SAR-PGDP May 31,1996 {_ ] Rev 3 3.15.1.7 General Plant Support 1 . Q systems in general plant support activities are listed. j 3.15.1.7.1 Cdticality Accident Alann Systems O Fuc don The Criticality Accident Alarm System (CAAS) is used to detect the elevated levels of gamma radiation that result from the mmunum criticality accident of concern and warn plant personnel in the event that a criticality accident occurs. See Section 3.12.6 for a description of this system. Boundary The system boundaries for the CAAS cluster unit include: 1. Gamma detector channel 2. Cluster logic module [ 3. Cluster housing The bounded components of the alarm horn include: 1. Local horn 2. Power supply to the horn 3. Backup battery for the cluster and horn 4. Trouble relays associated with loss of power and loss of air / nitrogen pressure The system 'ooundaries for the Radiation Alarm Cabinet in each building include: 1. Relay from the clusters 2. Relay to actuate the building / slave lights and horns. 3. Plant air system, back to the isolation valves 4. Building / slave lights and horns 5. Power supply for the buildingh' ave lights and horns (120 Volt), back to the first breaker 1 (./ 3.15-37

SAR-PGDP May 27,1998 RAC 97C240 (RO) The system boundaries for C-300 include:

1. 48 volt power supply from the radiation alarm annunciator cabinets (A and B)

2. Loss of power relays

3. less of power indication on the C-300 console

- 4. Building horn control switch 3.15.1.7.1.1 Portable CAAS QInnction For buildings that require permanent CAAS coverage, a portable CAAS can be used on a temporary basis until the permanent CAAS is in:talled. 'Ihese portable units can also be used when a permanent CAAS is out of service. The portable CAAS functions to detect the elevated levels of gamma radiation that result from the minimum criticality accident of concern and warn plant personnel in the event that a criticality accident occurs. These portable units are equipped with an electric horn. When used in this manner, the portable CAAS are connected to the building alarm system (the building lights and horns and the C-300 alarm). A portable CAAS may also be used for off normal conditions ia areas where there is no requirement for a permanent CAAS, bu'

• temporary need exists for portable C AAS coverage (e.g., a truck containing fissile material in an outdoor area). When used in this manner, the portable CAAS will not be tied to a permanent building alarm system, iv.:t the portable CAAS alarm will be audible in all areas reqairing unmediate evacuation.

See Section 3.12.6 for a description of this system. Boundary The system boundaries for the portable CAAS unit include:

1. Gamma detector channel

2. Cluster logic module

3. Cluster housing

4. Associated circuitry

5. Local electric horn

6. Backup battery for the cluster and horn 7, Connecting cable to connect to the building system 3.15.1.8 Technical Services l

Q systems in technical services activities for buildings C-709 and C-710 are listed. l l 3.15-38

l l i SAR-PGDP May 27,1998 RAC 97C240 (RO) 3.15.1.8.1 Criticality Accident Alarm Systems Q Function The Criticality Accident Alarm System (CAAS) is used to detect the elevated levels of gamma radiation that result from the minimum criticality accident of concern and warn plant personnel in the event that a criticality accident occurs. See Section 3.12.6 for a description of this system. Enu' dan The system boundaries for the CAAS cluster unit include:

1. Gamma detector channel

2. Cluster logic module

3. Cluster housing The bounded components of the alarm horn include:

1. Building alarm horn l

2. Backup battery for the cluster

3. 24 V DC Power Supply l

4. Uninterruptible power supply l

The system boundaries for the Radiation Alarm Cabinet in each building include:

1. Relay from the clusters

2. Relay to actuate the building / slave lights and horns.

1 I l 3.15-39 i I

m a 1 SAR-PGDP May 27,1998 RAC 97C240 (RO)

4. Building / slave horns ~

l S. Power supply for the building / slave horns (120 Volt), back to the first breaker l l l 3.15.1.8.1.1 Portable CAAS Q Function For buildings that require permanent CAAS coverage, a portable CAAS can be used on a temporary basis until the permanent CAAS is installed. These portable units can also be used when a permanent CAAS is out of service. The portable CAAS functions to detect the elevated levels of ganuna radiation that result from the minimum criticality accident of concern and warn plant personnel in the event that a criticality accident occurs. These portable units are equipped with an electric horn. When used in this manner, the portable CAAS are connected to the building alarm system (the building lights and horns and the C-300 alarm). A portable CAAS may also be used for off normal conditions in areas where there is no requirement for a permanent CAAS, but a temporary need exists for portable CAAS coverage (e.g., a tmck containing fissile material in an outdoor area). When used in this manner, the portable CAAS will not be tied to a permanent building alarm system, but the portable CAAS alarm will be audible in all areas requiring immediate evacuation. See Section 3.12.6 for a description of this system. Boundary The system boundsries for the portable CAAS unit include:

1. - Gamma detector channel

2. Cluster logic module

3. Cluster housing

4. Associated circuitry

5. Local electric horn

6. Backup battery for the cluster and horn

7. Connecting cable to connect to the building system 3.15-40

r --~ - - - - - - - - - - - - - - - - - ~ - - - - - - - - - - - - - - - - - - - ~ - - j. \\ SAR-PGDP Chapter 4, Appendix A April 15,1998 l-Rev.24 23 INSTRUMENTATION AND CONTROL SYSTEMS / FEATURES 23.1 Criticalky Accident Alarm Systess L The Criticality Accident Alann System (CAAS) is used for warning plant personnel of a criticality incident. The system is desiped to detect gamma radiation and provide a distinctive, audible signal diat will alent personnel to evacuate the areas that are potentially affected. i A block diagram of the overall system configuration is depicted in Fig. 2.5-1. In addition to the devices described in the figure, one other type of detector is associated with the system. This detector is identified as the argon gammagraph detector. This dc+ector and its logic was not changed or affected by the changes for the HAUP and will not be discussed. For more informahon on these devices and their functions, refer to Sect. 3.12.7 of the PGDP SAR. l The CAAS was significantly affected by the HAUP due to the additional areas requiring criticality alarm coverage, ne entire system will be described and reviewed for Mility. l 23.1.1 Principal Design Basis and Criteria -De primary input (i.e., principal design criteria) for the CAAS is ANSI /ANS 8.3. He following design critena support the present bases for CAAS at PGDP. l-23.1.1.1 Text Deleted - l 2.5.1.1.2 ANSUANS 8.3 ' l. Gamma radiation detectors shall be capable of detecting a enticality that produces an absorbed dose in l L free air of 20 rads of conibined neutron and gamma radiation at an unshielded distance of 2 m from the l fissionable material within 60 seconds. Areas where this requirement is not met must have adequate , justification for not providing alarm coverage. It should be noted that this requirement is not applicable to areas containing material less than I wt % "4J. l

2. The system shall automatically initiate an evacuanon alarm sipal within one half second of the alarm l

setpoint being exceeded, ne building' evacuation alarm system shall be ' capable of being manually activated from a central remote location.

3. Text Deleted l

I

4. The system shall remain in an alarm condition after initinuon regardless of radiation levels returning to normal until a manual reset of the alarm has been accomplished. Reset capability shall be limited in access to preclude inadvertent reset and shall be located outside the area to be evacuated.

I

5. The local evacuation alarm system shall be able to perfona its function without the aid of off-site alternanng current (ac) electrical power or the plant air system.

6. De system shall be designed to preclude inadvertent ininstion signals to the extent practical to provide system credibility.

1 2-5

SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO)

7. The system shall be designed to provide an indication of system malfunctions for alerting personnel of maintenance requirements.

8. A means shall be provided to test the response and performance of the system (excludmg the sounding of the alarm) without causing an evacuation alarm. In addition, the portions of the system not affected by the test shall still remain functional.

9. The system shall provide sufficient information to the Central Control Facility (CCF) to allow implementation of site emergency response procedures for criticality accidents; this information shall be provided independent of off-site ac power for a minimum of 4 hours.

10. De signal generated by the evacuation alarm system should be capable of producing an overall sound pressure level which is not less than 10 dB above the overall maximum typical ambient noise level, and 2

in any case not les.4 than 75 dB nor greater than 115 dB (reference to 20 uN/m ) at *he ear of the -individual at every location from which irnmediate evacuation is deemed essential.

11. The'CAAS shall remain operable in the event of seismic shock equivalent to the site-specific design basis earthquake or the equivalent value specified by the Uniform Building Code.

Each of these criteria will be addressed in Sect. 2.5.1.3 by illustrating how the system meets the requirements. 2.5.1.2 System Description The CAAS is primarily divided into three ategories for description. These three areas are the local alarm system, building alarm system, and the Building C-300 CCF alarms and controls, ne local alarm system includes the individual cluster unit detectors that provide detection capability for the entire system. The cluster unit detection system actuates both visual and audible alarms in the affected area (s). The personnel alarms that would be activated consist of: a local horn (continuous high pitched blast) actuated by plant air or by mtrogen or an electronic horn, . building horns (air or electric), red rotating or strobe beacons located on the outside of buildings, and e an audible and visible alarm on the Building C-300 CAAS control panel. The local and building horns produce a loud, distinctive sound and are used as an emergency signal for immediate evacuation of all personnel from the building or area. Due to the significant number of changes in this system, the local and building alarm system will be described first. Once the basic concept has been established, each building or area will be discussed in detail to provide information on the specific configuration and how the system is arranged. - 2.5.1.2.1 Local alann system The local alarm system consists of three major devices: the cluster unit, the localjunction/ horn control box, and the alarm horn. The cluster unit sends the required input to the building alarm system and to the CCF. He individual local alarm units are located throughout the plant as indicated on Fig. 2.5-2. C-710 and C-720 do not have a specific local horn. 1 2-6 l l

SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO) Each detector channel has three possible states: normal, fault alarm, an4 radiation alarm Pre-determined values of fault alarm and radiation alarm are selected to provide annunciation if the unit falls outside the normal operating range (10 mR/hr radiation). In the normal state, the meter on the front panel of the detector channel indicates a pre-determined normal background reading on the upper scale, and no other alarm indicators are activated. If somethmg in a detec, tor channel fails and causes the signal level to drop to a fault alarm point, the detector channel will go into the fault state, actuating the FAULT ALARM light on the front panel. If a detector channel goes into the fault state, the cluster logic module will detect it, then activate an audible alarm and turn on a trouble light at the CAAS console in the CCF. Radiation levels of 10 mR/h or more abm the background reading will exceed the cluster unit's alarm setpoint, and the cluster unit will c into the alarm state. In t's cate, the RAD ALARM light on the front E panel of the detector channel will turn on. In addition to providing space for mounting the three detector channels ami the cluster logic module, the cluster unit housing also provides electronic connections from each detector channel to the cluster logic module. Also mounted on the back of the cluster unit housing is the cluster unit housing / mother board assembly. This assembly provides power supply connections to each detector channel, a connection slot for the cluster logic module printed circuit board, and connections to cable connectors slots J2, J3, J5, and J7 on the cluster unit housing. If only one duector channel goes into the alarm state, the cluster logic module considers it a malfunction and generates a trouble alarm on the CAAS console at CCF. If two detector channels go into alarm at the same time, the cluster logic module considers it genuine and generates a radiation alarm. If two detector channels are already in the fault state and the third detector channel goes into alarm, the cluster logic module generates a radiation alarm. To summarize, a radiation alarm will occur if two or more (any two) detector channels go into the alarm state or if only one goes into the alarm state while the other two are in the fralt state. All other combinations of abnormal states will cause a fault alarm. A radiation alarm signal generated by the above sequence not only turns on the RAD ALARM light on the detector channel but also turns on the ALARM light on the cluster logic module and the 10-mR indicator light or strobe on the CAAS console. In addition to the panel alarm light indicators, a radiation alarm signal activates red rotating or strobe beacons located on the exterior of the affected building, and a group of evacuation horns located in the affected area along with any applicable slave horns. The cluster logic module for all detector assemblies was replaced with the cluster logic module developed for K-25 alarm rys:cm appucation. The new module operates in the same manncr as the original logic module with the exception that two output circuits are available for functional redundancy. The voting logic for detector channel input is identical to the previous module. There are two channels of output relays, K4 and KS. An analysis' was performed on the new module to determine the capability to meet the single failure requirements. The results indicated that the logic gates and the relays met the functional single failure requirements. The primary reason for this change is to provide additional protection against single failure in the individual cluster units. Local horn alarm description Local horn alarms are located at each of the cluster unit installations except at C-710 and C-720. The l local horns are either electronic or are actuated by plant air during the normal operating mode and by nitrogen (N ) from a dedicated cylinder as a backup if the plant air pressare decreases below a preset value. 2 An exception to the above statement does exist. Plant air is not available in Building C-746-Q: therefore, a dual N cylinder manifold serves as the primary source and a single N cylinder serves as the backup for 2 each of the two clusters in this building. C-710 and C-720 have all electric horns with no dedicated local horn. 2-9

1 SAR-PGDP Chapter 4, Appendix A April 15,1998 Rev. 24 De air operased local ham alarm consists of a clarion horn, a compressed nitrogen gas cylinder, and a local horn control box which is elecincally v =3+1 through ajuncnon box to components locmed in the cluster unit. A simplified electncal schemanc of the circuit is shown in Fig. 2.5-10. De local ham control box is normally mounted on a wall or column just below the cluster unit andjuncnon box; the neopa supply, a 2200-psig cylinder, is secured on the floorjust below the local ham control box. De horn is mourned several feet higher than the local horn control box. Fig. 2.5-11 shows a typical field irw=Itatwi of the localhorn alem synem unit. The local horn control box contams a nitrogen pressure regular, three pressure swaches (SSA, SSB, and S6), a double solenoid four-way valve to control pressure to the hora, a plant air conneccon with a backflow check valve, a swnch and test socket to accommodate a test /comrol unit, a temunal block for electncal connections, and miscellaneous hardware. Fig. 2.5-10 shows the enactncal dw circuit, and Fig. 2.5-12 shows the w-w;==: layout and connecnons in the local ham control box. A pressure regulator regulates the nitrogen pressure at 5 psi below plant air pressure but not higher than 80 psig which is requeed to provide the necessary sound level frorn the hom. Pressure switch SS monitors the i regulator presure through the trouble circuit. One pair of SS conmets (SSB) is set to open on decressmg pressure at approximately 75 psig, and the other set of contacts (SSA) is adjusted to open on increasing pressure at approximately 135 psig. Pressure swnch S6 on the supply cyleder is set to open at or befom 900 psig on decreasing pressure. De two pressure swnches me connected electncally to give a " FAULT ALARM" indication at the cluster unit and a " CLUSTER TROUBLE" alarm at the CAAS console if the pressure being measund exceeds the y,J ilimits. Solenoid valve val is pilot operated so that inlet pressure aids the plunger movement. For the valve to open, the OFF coil must not be &~, d, the ON coil must be a, 4, and there must be at least 10 psig of pressure from the output of the regulator. To re7et or close valve val aAer it has been actuated or out of savice, the ON coil must be without power and the OFF coil must be s_, d while there is pressure (10 psig or more) in the valve. Some pressure must be present for the reset acnon, so a slight loss of nitrogen may be associated with resetang the solenoid valve. A local horn control box failure is *W to manifest itself as one of the following aa'la% from the high-pressure side of the box, which is signaled by a " CLUSTER TROUBLE" alarm at the CAAS console; seat lankage of the cylmder gas regulator courbp pressure increase in the low-pressure part of the local horn control box, which actuates a " CLUSTER TROUBLE" alarm at the CAAS console: or failure of the solenoid valve to either open or close when a-, d. The local horn can be reset by two ='haA ne first method irrelves manually movmg the piston of solenoid valve VA-1. This manipulation is done by removing the end caps and pushing the pistons to the reset posanon. De second method is by connectmg a Reset Module, which has a red push-buson swach, to Pins 13 and 14 oftest Connector J-3 on the cluster unit housing. Bis Reset Module is available in each building frorn . maintenance personnel. He' module was designed and fabricated by the PGDP Instrument Maintenance l Department.. The module resets the alarm by depressing the switch and applying 24-V de to the OFF solenoid and resetung the valve. The nitrogen supply cylinder is capable of delivering nitrogen to the horn for at least two minutes shouki l j the plant air symem fail, his would provide sufficient waming to personnel in the affected area. j 2.5.L2.2 BuHding alarin system Figure 2.5-1 is an overall layout drawmg of the cluster tarat== and connecnons of the basic compenents of the CAAS. Each covered area contains building horns that pamde audible wammgs inside the buildings. l Rotating or snobe red beacons located on the outside of the affected buildings serve as a visible waming not to q enter the buikhng. Local radiation alarm cabinets (RACs)10 which the outputs of all the cluster units in the . l alarmed area -/ l 2-10 t .._j

F j l \\ i l l SAR-PGDP Chapter 4, Appendix A April 15,1998 j Rev.24 l 2.5.13.1 Criteria 1-11 l l l In Building C 333, the only area providal with permanent coverage from the cell floor units is the area l of Unit 6. As indica'ed in Table 2.6-1, the assay gradient for 5 wt %"' U would generally have a top assay of about 0.8 wt % "'U for a 0.2 wt % "'U tails in all of Building C-333. Although there are some vanations with this configuration and assay level, normal operation in this facility will generally be less than I wt %* U with the exception of Unit 6 which could slightly exceed I wt %* U. Herefore, only Unit 6 (highest assay area) will be protected by a local alarm unit during all modes of operation. Although the production within this portion of the casende is expected to be in the I wt %* U range and less, the potential for feeding up to 5 wt % "U is provided in C-333-A. His feed would bypass the entire C-333 cascade provided the feed assay level ex-W he level for C-333 enrichment. He feed line is maintained in a gaseous state. which will provide one t method of criticality control (i.e., density). In addition, the moderation within the system is controlled by maintaining system integrity and the temperature and pressure within acceptable ranges as indicated in Sect. 2.6.2.3. The cell floor is provided with coverage by use of the cluster unit AJ even though it is located on the ground floor. Based upon this analysis, Building C-333 has adequate permanent CAAS coverage for operation. In Building C-331, the areas with some overlapping coverage include units 3 and 4. Rese two units could potentially contain uranium enriched greater than or equal to I wt %* U. The remaming two units are very low assay during normal operanon due to their primary roles as stnppers in the enrichment process. He remaming parts of the building are similar to the configumtion for Building C-333. Derefore, the same justification is applicable to the remaining areas of C-331. Based upon this analysis, Building C-331 has adequate permanent CAAS coverage for operation. In Building C-335, the areas pmvided with redundar.t some overlapping coverage include units 2,3, and

4. These units could potentially contain uranium enriched greater than or equal to I wt %* U. He remaming unit is very low assay during normal operation due to its primary role as a stripper in the enrichment process.

The remaining parts of the building are similar to the configuration for Building C-331. Therefore, the same justification is applicable to the remaining areas of C-335. Based upon this analysis, Building C-335 has adequate permanent CAAS coverage for operation. 2.5.13.2 Text Deleted 2.5.133 C-331, C-333, C-335, and C-337 (gmund floors) l The ground floor of buildings C-331, C-333, C-335, and C-337 has detection coverage with one cluster unit ) located on the ground floors and additbnal coverage pnmded by cell floor cluster units. In building C-337, each unit has CAAS coverage with some areas of overlapping coverage. He remaming parts of the building are similar to the configuration for Building C-333. Based upon this analysis, Building C-337 has adequate permanent CAAS coverage for operation. Building C-310 has two clusters wi:h some areas of overlapping coverage. Based upon this analysis, Building C-310 has adequate permanent CAAS coverage for operation. The building tie lint.s have enudity coverage as described in PGDP document KY/G-578 " Criticality Accident Alarm Coverage of the Interbuilding Tie Lines at the Paducah Gaseous Diffusion Plant". Building C-333A has two clusters with overlapping coverage. Based upon this analysis, Duilding C-333-A has adequate permanent CAAS coverage fcr operation. Building C-337A has one cluster with overlapping coverage form C-337. Based upon this analysis, Building C-337A has adequate permanent CAAS coverage for operation. Building C-360 has two clusters of overlapping coverage. Based upoa this analysis, Building C-360 has l adequate permanent CAAS coverage for operation. 2-13

8 SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO) Building C-400 has two clusters with some areas of overicpping coverage. Based upon this analysis, Building C-400 has adequate permanent CAAS coverage for operation. Building C-409 has two clusters of overlapping coverage. Based upon this analysis, Building C-409 has adequate permanent CAAS coverage for operation. Building C-710, a laboratory facility, has five clusters and Building C-720, a maintenance facility, has one cluster. C-720 has single cluster coverage only. As with all cluster units it has three detectors along with a functionally redundant logic module for sending mput to the building alarm system. Based on this analysis, this is acceptable for current operations. Building C-746-Q East, has one cluster and is used as a waste storage facility. As with all cluster units, each has three detectors along with a functionally redundant logic module for sending input to the building alarm system. Based upon this analysis, Building C-746-Q East has adequate permanent CAAS coverage for storage. Therefore, the coverage requirement of criteria 1 has been met. The CAAS provides coverage of all these areas by selecting the setpoint for initiation in accordance with ANSI /ANS 8.3'. The coverage area is calculated based upon the setpoint of 9.5 to 10.5 mR/h The cluster units were designed to meet the requirement of one-half second response time. This requirement verified by field testing to ensure system functionality. Figure 2.5-14 illustrates the method of initiating the building alarm horns from C-300 by placing the HORN CONTROL SWITCH in the ON j position and by having the HORN PERMISSIVE SWITCH in the ON position. This meets Criterion 2 as spe:ified in Sect. 2.5.1.1, Once an individual cluster unit detects and outputs an alarm condition, the alarm signal is saled in to prevent inadvertent reset when radiation levels return to less than alarm conditions. This can be seen by l reviewmg Fig. 2.5-6. The alarm is generated when the output from logic gates U3C 4011 and U3D 4011 or USC 4011 and USD 4011 cause transistor Q2 or Q3 to allow sufficient current through the K4 and K5 relays to initiate the alarm. Logic gates U3C 4011. U3D 4011, USC 4011, and USD 4011 are arranged in a " flip-flop" configuration (logic menwry) that remains in the alarm state until the logic reset signal is generated either locally or from C-300. In addition to the individual cluster units, the local alarm horns will remain in the alarm state after the cluster unit has been reset until the local reset circuit is applied to the horn control box as illustrated on Fig. 2.5-10 or until the nitrogen is depleted if plant control air is lost. j The building darm horns are maintained in the alarm condition by the local cluster until the cluster unit I is reset or the building horn is reset via the HORN CONTROL SWITCH being placed in the OFF position within C-300 (see Fig. 2.5-14). The building alarm lights require reset at the respective building RAC. l Therefore, all alarm circuits are sealed in once the initiation has occurred until a specific manual reset action has occurred. All of these devices can be reset from a remote location with the exception of the local horns. The basis for not having remote reset capability for the local alarms is to avoid the potential of an alarm being terminated prematurely by local personnel. Based on this review, the CAAS meets the intent of the requirements of Criterion 4 stated in Sect. 2.5.1.1. As indicated in the description provided in Sect. 2.5.1.2.1, the clusters are equipped with a direct current (de) battery backup with a design rating of four hours upon loss of ac power to the cluster unit. This supply will supply sufficient power to all necessary components within the system to actuate the local alarm without ac power. In addition to being independent of electrical power, the local alarm horn can operate for a minimum of two minutes without plant control air. The two-minute time frame is sufficient to meet the requirement stated in Sect. 4.4.1 of ANSI /ANS 8.3 that says the alarm signal is for immediate evacuation purposes only. The nitrogen supply is capable of delivering the design rate of flow to the clarion horn by proper operation of the backflow check valve and the pressure switches within the local horn control box. This meets the requirements of Criterion 5 as stated previously. Criterion 6 states that the system shall be designed to preclude inadvertent initiation signals from being l generated (i.e., false alarms) to the extent practical. This requirement has been met by providing a logic circuit that requires a minimum of two detector channels to provide an alarm output to the logic board simultaneously (except when two detectors are already in a faulted condition). Individual component failures from the detector 2-14

) 4 6 SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO) circuit to the building alarm system could cause spurious operation of the system. However, past operational history has shown this portion of the system to be reliable in preventing spurious alarms within the system. Therefore, based upon the detection logic and past operational experience, the system configuration meets the applicable criterion. Section 2.5.1.2.1 previously described the self-testing capability of the individual detector channel by the function of the LED light source within the assemblies. This meets the requirements for indication of system malfunctions for the detector channels (Criterion 74 In addition to this capability, the power supply circuits are monitored with appropriate alarm indication within C-300 as well as the local horn control Inxes as described previously. In addition to the self-monitoring of the system, periodic testing of the system is also performed as described in Sect. 5 to verify proper system operability. Test circuits and switches are located throughout the system to allow for system verification as described in Sect. 5. In addition, local alarms will remain operational as long as the individual alarm is not being tested. These local alarms will still send input to the building alarms during these conditions unless the building alarms have been disabled before the test. The individual detector channels have their own test circuit along with the cluster logic module. The building alarm system can be tested by the HORN CONTROL SWITCH as previously described. Therefore, the system meets the testability requirement specified in Criterion 8. As described in Sect. 2.5.2, all of the alarms and fault conditions are displayed in C-300. Section 2.5.2 gives a detailed evaluation of this requirement (Criterion 9) for the CAAS. Criterion 10 is one of the most difficult portions of the system to verify by analysis. Criterion 10 requires diat the horn provide sufficient (greater than 10 dB above background) sound without exceeding the maximum level (115 d'B) at the ear of the !ndividual. At PGDP, measured audibility surveys have shown that some of the areas meet the intent of this criterion, however many areas do not. ANSl/ANS 8.3-1986, Sect. 4.4.1, requires that the alarm signal for the immediate evacuation area only be of sufficient volume and coverage to be heard in all areas that are to be evacuated. Those areas that do not have sufficient volume to be audible are being addressed under the PGDP Compliance Plan. VIP report number PIP:45-894KM3, lmprove Maintenance and Monitoring ofRadiation Alarm System", documented that the present system could not be proven to meet Criterion 11. This section requires that the system remain operable in the event of a seismic shock equivalent to the site specific design basis earthquake or the equivalent value specified by the Uniform Building Code. The CAAS does not meet seismic qualifications. Specific exceptions to ANSI /ANS 8.3 criteria are listed in SAR Section 1.6. j 2.5.1.4 CAAS Safety Class Equipment and Instrumentation 1 The CAAS is designated a safety system. The core of the CAAS is the radiation detection cluster unit, j the alarm horn control box, and the local alarm horn which are installed throughout PGDP where fissionable material is handled and a non-trivial risk of a criticality exists. These devices must function in order to initiate a prompt evacuation of personnel from the area of detection in the even' of an inadvertent criticality. The following are the components of the CAAS which are identified as safety system components: building CAAS horns and lights (lights are not safety system components in C-710 and associated facilities) gamma criticality monitors (cluster): l l three detectors, l one common control panel; 2-15 L l I L

q n SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240(RO) alarm horn control box (where applicable): l - -on nitrogen regulator (where applicable), two pressure switches (where applicable), one air to nitrogen control valve (where applicable), alarm cabinet (relay matrix): control relays (W, Y, and Z relays), l

• local alarm horns.

2.5.2 Central Control Faculty Provisions and Features 2.5.2.1 SystesaIbeription .At the radiation alarm system console, the operator can identify cluster units in an " ALARM" or " TROUBLE" state, silence alarms, test and tum on building horns, and disable alarms. The radiation alarm system console is located in C-300 (CCF). Ponions of the radiation alarm system console front panel are shown in Fig. 2.5-15. Ponion "A" of Fig. 2.5-15 is a plot plan that depicts the alarm indicators and controls associated with each cluster unit. Figure 2.5-16 shows a grouping of l Micator lights and control switches, all of which are common to the radiation alarm system console. The l functions of the components shown in Fig. 2.5-15, portions "A, " "B," and "C," are discussed below. A group ofindicators and switches provide indications and controh for one cluster unit. This cluster unit plot plan is shown in portion "A" of Fig. 2.5-15. 1, 10-mR Alarm Light-The red 10-mR light comes on, along with the console horn, when a criticality alarm signal is received

from the related cluster unit. After the alarm condition is over, this light is reset by pushmg the CL

' RESET (cluster reset) switch, which turns off the 10-mR light and resets the logic in the cluster unit (see Sect. 2.5.1).

2. Memory Light

- This light is pan of the MEMORY /CL RESET combination as shown in Fig. 2.5-15, portion "A." When a criticality event signal is received, the red 10-mR and blue MEMORY lights come on and the red 2-R light comes on if conditions so warrant. Reset of the 10-mR light is discussed in Item 1; however, after the criticality event is over and no alarm signal is being received from the cluster unit, the MEMORY light will remain ON until the console operator actuates the MEMORY RESET switch located in the common indicators and controls section (see Fig. 2.5-15, portion "B").

3. CL (Cluster) Reset Switch The CL RESET switch is pushed to reset the logic in the cluster unit and turn off the 10-mR light at the radiation alarm system console when a criticality event is over.

2-16

SAR-PGDP Chapter 4, Appendix A April 15,1998 Rev. 24 i l 4. Cluster Trouble Light i. This light comes on when r.n abnormal condition is in the system. This indicates trouble at the 10-mR cluster,2-R cluster, local hom control box, or other electncal system pnA,' ens.

5. Building Hom On This light indicates that the evacuation homs located in the building covered by the associated cluster unit have been turned on from the control room by moving the hom control switch (CS-310 in Fig. 2.5-15, pornon "A") to ON afler the HORN PERMISSIVE swach (Fig. 2.5-15, portion "B"), located in the common indicators and controls section, has been tumed ON.

6. Building Hom I.ocked Out This light comes on when the console opemtor has disabled the circuit that energizes the building horns in the area covered by the associated cluster unit. The console operator disables the horn circuit by moving the hom control switch (Fig. 2.5-15, pomon "A") to the OFF position.

7. Hom Control Switch (CS-310 in Fig. 2.5-15, portion "A")

The horn control switch has three positions which me OFF, AUTO, and ON. In the OFF position, the building homs are locked out as described in item 5. In the AUTO position, the building homs and the red beacons are automatically tumed on in the area covered by the associated cluster unit when a criticality 4 alarm is received from the cluster unit. In the ON position, building horns can be manually tumed on in the area covered by the cluster unit if the HORN PERMISSIVE switch is in the ON position. A group of indicators and switches located on the lower right side of the console provides common indicanons and controls for all cluster unit systems. These indicators and controls are shown in Fig. 2.5-15, pomon "B." The functions of these lights and switches are b'ved below:

1. DirectCurrentPowerFailure A loss of 48 V de power to the system causes this light to come on.

2. Ac Power Failure A loss of 120 V ac power causes this light to come on if 48 V de power is available.

3. Hom Permissive On This light comes on when the HORN PERMISSIVE switch is moved to the ON position. In this posit on, i

the console operator can tum on the building hams in the area covered by the associated cluster unit (s) by tuming the hom controlswitch to ON. I 2 17

' SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO).

4. Hom Permissive Off This light co nes on when the HORN PERMISSIVE switch is moved to the OFF position. In this condition, the console operator cannot turn on the building borns by positioning tle horn control switch to ON.

5. Horn Permissive This switch functio i was explained in Steps 3 and 4.

6 Alarm Silence This switch silences the audible (bell, buzzer, etc.) alarm signals existing at the radiation alarm system

console,

7. System Test This switch tune on all annunciator alarms, console MEMORY lights, and audible alarms to test dieir electrical operation

8. Memory Reset.

The MEMORY light on the control, which indicates present or past existence of'a criticality event, is not automatically turned off when the criticality event is over and the criticality alarm s.ignal no longer ~] exists. The MEMORY light must be turned off by the console operator using the key-operated MEMORY RESET switch. I If the building has an argon ganunagraph alarm on the console, an alarm will sound and a light on the panel sill indicate a radiation alann when the Argon Gammagraph in the field senses radiation. A HIGH LEVEL RANGE RESET switch resets the alarm lights after a criticality event is over. The overall pictorial layout of the radiation alarm system console is shown in Fig. 2.5-16 and Fig. 2.5-17. l 2.5.2.2 System Analysis The changes made for HAUP in the CCF were primarily to support the major additions of local clusters and their associated input to the building alarm system. The hazards involved were mainly of the . electrical hazard. Some failure modes could be created within the CAAS. However, these are evaluated in Sect. 2.5.1. Based upon this evaluation, no additional requirements were addressed. l 2.5.2.3 Safety Features and Controls i Although none of this equipmem is specifically required to perfonn a function to detect and/or alarm ) u should an actual criticality incident occur, the equipment connected to the system will be operated in such a manner as to ensure it does not prevent the required portions of the system from actuating should an alarm actually be required. As required, design features for safety, admuustrative controls, and surveillance were developed to support operation at enrichments up to 5.5 wt % SU. These safety features are listed below. l 2-13 { i L.

l j \\ i SAR-PGDP Chapter 4, Appendix A April 15,1998 Rev.24 2.5.2.3.1 Text Deleted l 2.5.2.3.2 SurveiBamce Requirennent

2. Annual serificanon ofoperability of the detector unis shall be yafunied using a radiaSon sousee.

l

3. Quarterly venfication of local alann operability rhall be perfonnat This testing shall include verification that nitrogen pressure is greater than 900 psig, banery 1est, and applying a back pressure on the check valve l

at the nitrogen / plant air interface to ensure operability of the check valve. The nitryen system tests are not required where nitrogen backup is not required. 4 Quarterly verification of building alann opetsbility shall be performed. This testing shall include verification that nitrogen pressure is greater than 900 psig, banery test, and applying a back pressure on the l check valva a* the nitrogen / plant air interface to enuse operabdity of the check valve. The nitrogen system tests are not required where nitrogen backup is not required.

5. An integrated test of the entire CAAS shall be sfuuied on an annual basis in accordance wifi l ANSI /ANS 8.3, Sect 6.4.

) i 1 ) 1 ) 1 i ) ) l I l l 2-1P l l l

l SAR-PGDP Chapter 4, Appendix A May 27,1998 RAC 97C240 (RO) ) Table 2.5-1. Criticality clusters and building alarms l Building I m al Notes J clusters / alarms l C 310/310-A G and H Local horns with building horn. l C-331 J, K, and L Local horns with building horn. C-333 Z and AJ Iocal horns with building horn. C-333-A AA and AB Local horns with building horn. Either cluster will also actuate building horns in C-333 l C-335 A, B, C, and AF Local horns with building horn. j I C-337 T,U,V,W,X, Local horns with building horn. Cluster N in C-337-A Y, and AK will actuate building horns in C-337. Clusters V and X in C-337 will also actuate a building horn in C-337 A l C-337-A N Local horns with building horn. Cluster N in C-337-A will actuate building 3 horns in C-337. C-360 R and S Inal horns with building horn. C-44V) D and E local horns with building horn. l l C-409 P and AE Local horns with building horn. j C-710 AM,AN,AP, Building horns. AQ,AR C-746-Q AC and AD local horns with building horn. C-720 AL Building horn. ) l 2-20 l

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1 SAR-PGDP Chapter 4, Apperuhx A May 27,1998 RAC 9?C240 (RO) l i i i l l t BUILDING C-710 %= M M -= w se j \\ = = n i "P "P "P "P ",e - P se - se - ne. a% =% =% M M M M fG l a \\ I J i I \\ l Fig 2.5-17. Radiation alarm system console expansion. lL 2-52a

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TSR-PGDP PROPOSED May 27,1998 RAC 97C241(R0) SECTION 2.6 SPECIFIC TSRs FOR CAAS (NON-CASCADE FACILITIES) 2.6.4 GENERAL LIMITING CONDITIONS FOR OPERATION 2.6.4.1 CRITICALITY ACCIDENT ALARM SYSTEM LCO 2.6.4.la: Criticality accident detection shall be operable. APPLICABILITY: In areas, equipment, or processes in the facilities listed in the table below which contain greater than 700 grams of"5U at an enrichment greater than or equal to 1.0 wt % "5U. Building / Facility Number Building / Facility Name CAAS Cluster and/or Function C-400 Cleaning Building D, E C-409 Stabilization Building P.AE C-710 Technical Services Building AM, AN. AP, AQ, AR l C-720 Maintenance and Stores AL Buildings '1 C-720-C Converter Shop Addition AL C-728 Motor Cleaning Facility AL C-746-Q-1 High Assay Waste Storage AD 2.6-3

e TSR-PGDP PROPOSED May 27,1998 RAC 97C241 (RO) SECTION 2.6 SPECIFIC TSRs FOR CAAS (NON-CASCADE FACILITIES) 2.6.4 GENERAL LIMITING CONDITIONS FOR OPERATION 2.6.4.1 CRITICALITY ACCIDENT ALARM SYSTEM (continued) SURVEILLANCE REQUIREMENTS: Surveillance Frequency SR 2.6.4.la-1 Calibrate CAAS system equipment. Annually BASIS: The CAAS is used to warn plant personnel of a criticality or radiation accident. This system is designed to detect radiation and provide a distinctive, audible signal which will alert personnel to move from those work areas which are potentially affected. The design of the system, three detector modules per cluster, provides protection for criticality events even with partial losses of required equipment. The CAAS also provides detection coverage in most areas by using an overlapping pattern of individual cluster units. Criticality concerns with the listed facilities are associated with the handling of fissile materials. The action items maintain the facility in steady state operations to limit the potential for these concerns to the extent possible. The alarm signal is provided by sounding building horns which sound upon a signal from any cluster, and by sounding in some locations a local horn associated with each individual cluster. The building horns for C-709 and C-710 are configured in two separate networks, either of which can independently sound the required evacuation signal. The building horn configuration in C-709 and C-710 allows the CAAS for those buildings to remain operable even when one of the independent horn networks is temporarily out of service. Providing another means of coverage (i.e., portable detector / alarm, personal alarm device, etc.), restricting operations, or restricting access to the area l in the event of the loss of detection will establish protection. ISAR Chapter 4, Appendix A, Section 2.5.1.1.2, SAR 5.2, ANSI /ANS 8.3] Facilities containing criticality accident alarm systems (other than those covered by TSR Sections 2.1-2.4) include C-400, C-409, C-710, C-720, C-720-C, C-728, and C-746-Q-1. l l l 2.6-5

p . TSR-PGDP PROPOSED May 27,1998 RAC97C241 (RO) SECTION 2.6 SPECIFIC TSRs FOR CAAS (NON-CASCADE FACILITIES) 2.6.4 - GENERAL LIMITING CONDITIONS FOR OPERATION l I 2.6.4.1 CRITICALITY ACCIDENT ALARM SYSTEM (continued) l SURVEILLANCE REQUIREMENTS: Surveillance Frequency SR 2.6.4.lb-1 Test the CAAS, local cluster horns and Quarterly building horns. SR 2.6.4.1b-2 Verify that the nitrogen supply pressure to Quarterly the cluster horns is at least 900 psig. SR 2.6.4.lb-3 Verify that the condition of the battery Annually backups to the electronic horns are sufficient to power the horns for at least 120 seconds. l BASIS: The CAAS is used to warn plant personnel of a criticality or radiation accident. This system is designed to detect radiation and provide a distinctive, audible signal which will alert personnel to move from those work areas winch are potentially affected. Evacuation of the area of inaudibility and restricting access to those areas will eliminate the potential for increased consequences due to personnel not hearing an alarm. The design of the system, three detector modules per cluster, provides protection for criticality events even with partial losses of required equipment.. The CAAS also provides detection coverage in most areas by using an overlapping pattern of individual cluster units. Criticality concerns with tie listed facilities are associated with the handling of fissile materials. The action items maintain the facility in steady state operations to limit the potential for these concerns to the extent possible. The alarm signal is provided by sounding building horns which sound upon a signal from any cluster, and by sounding in some locations a local horn associated with each individual cluster. The building horns for C-709 and C-710 are configured in two separate networks, either of which can independently sound the required evacuation signal. The building horn configuration in C-709 and C-710 allows the CAAS for those buildings to remain operable even when one of the independent horn networks is temporarily cut of service. Providing another means of coverage (i.e., portable detector / alarm, personal alarm device, etc.), restricting operations, or restricting access to the area in the event of the loss of - alarms will establish protection. Facilities contairdng criticality accident alarm systems (other than those covered by TSR Sections 2.1-2.4) include C-400, C-409, C-710, C-720, C-720-C, C-728, and C-746-Q-1. [SAR Chapter l 4, Appendix A, Section 2.5.1.1.2, SAR 5.2, ANSI /ANS 8.3] I The nitrogen bottles which backup plant air for the local cluster horns are standard cylinder size 1A (1.55 ft',9 x 51 inches) and provide for 120 seconds of horn actuation when at their mmimum acceptable pressure of 900 psig. 2.6-7 l

4 TSR-PGDP PROPOSED May 27,1998 RAC 97C241 (RO) SECTION 2.6 SPECIFIC TSRs FOR CAAS (NON-CASCADE FACILITIES) 2.6.4 GENERAL LIMITING CONDITIONS FOR OPERATION 2.6.4.1 CRITICALITY ACCIMNT ALARM SYSTEM (continued) BASIS (continued): The quarterly surveillance of the CAAS, local cluster horns and building horns consists of placing the cluster in the test mode with a keyswitch, and manually causing two detector modules to generate radiation readings above tb alarm setpoint. The cluster electronics determines that this meets the high radiation alarm critena and propagates a high radiation alarm signal to the rest of the system. This signal activates the high radiation alarm light and bell in C-300, causes the local cluster horn to sound (where applicable) and activates the building CAAS horns and lights. Each l horn and light is qualitatively verified to be operating. This test is a horn and light functional test and each module combination is tested to generate the high radiation signal. i 2.6-8 ) 1 )

y y y g y o0 o l t 2 ri s a s 1 yl ef e n eA w r r f h oot 0 od t t e h r s e e1 s oS sbf 7 i pre lsCeAd a - r i o f s Al h m s w2 d t eAni - n wid o o e a iCo e S qh tyd aP mc f n r ) ts d u y e er 9. - e e rd o0 r r e t u R eif 7 e o t f r d s v e - n s w~ e o - n a oreCo i r t p al r e r cph ep h n p e r t c owhr is t s nt u wees h o S i n a s r r yi ( pot ed oo bd p s C . wnf h n n A 's no ad ge a d t r oppe ndi ly e Vei ri cCkuid t ul v p. n 0 ts e u nAc qi opf o 2 a e ur u a 1 lcfuVb rb ps s p = moC m se r d a d n u la y a l d lp cn n s a p n i f u y o s s s r r e a g e e t d t h n s t s n y u i u ts g S o i s, l n c n b s , e d ne i o rh u e i m ol et lc s u e cd r it ts n n t s o l e i s u e n u i t m c f y i t e S n w d c D ur e n t u m r e h e a o t t y r cecl b r o u r r a e t a l u e o ,f n r s t d og t S d A lcd mg yr n i e Q u t n ri w o n r a is ew o c omiu e A B l t g t

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. TSR-PGDP PROPOSED May 27,1998 RAC 97C241 (RO) 23.3.3 Crideauty Archt Alarm Systems [C-400, C-409, C-710, C-720, C-720-C, C-728, l C-746.Q I] 2.4.3.3.a Criticauty Accident Alann System - Detection I~ APPLICABILITY: In areas, equipment, or processes which contain greater than 700 grams of"SU i at an enrichment greater than or equal to 1.0 wt % m3U. LCO: Criticality accident detection shall be OPERABLE. ACTIONS: TSR 1.6.2.2.d is no: applicable. CONDITION REQUIRED ACTION COMPLETION TIME A. Areas, equipment, or A.1 Implement the following for areas, processes not covered by equipment, or processes applicable to criticality accident this LCO and that are not otherwise detection. covered by criticality accident detection. A.1.1 Discontinue operations with fissile IMMEDIATELY material. M A.2.1 Restore criticality accident detection by 4 hours installing portable CAAS unit providing required criticality accident detection. OR A.2.2 Restore criticality accident detection to 4 hours OPERABLE status. B. REQUIRED ACTION B.1 Continue to comply with REQUIRED IMMEDIATELY A.2.1 and A.2.2 not ACTION A.1.1 ,i satisfactorily M L accomplished. B.2 Evacuate and restrict access to the area IMMEDIATELY. applicable to this LCO not covered by criticality accident detection, except i individuals with an alternate means of criticality detection and alarm notification, such as a device that will y alarm on sensing a 10 mr/hr dose rate. M B.3 Continue actions to restore criticality IMMEDIATELY accident alarm system detection to l OPERABLE status. l SURVEILLANCE REQUIREMENTS: SURVEILLANCE FREQUENCY SR 2.4.3.3.a-1 Calibrate Criticality Accident Alarm System equipment. Annually 2.4-9 l 1

1' TSR-PGDP PROPOSED May 27,1998 l RAC 97C241 (RO) [ SURVEILLANCE FREQUENCY E SR 2.4.3.3.b-3 Verify that the condition of the battery backups to the Annually 4-electronic horns are sufficient to power the horns for at i least 120 seconds. l BASIS: l' C The CAAS is used to warn plant personnel of a criticality or radiation accident. This system is designed to detect radiation and provide an audible signal which will alert personnel to move from those work areas l, which are potentially affected. Criticality concerns involve movement of fissile material and moderator l. introduction. The REQUIRED ACTIONS maintam steady state operations (relative to criticality control) [: to limit the potential for these concerns to the extent possible. Discontinuing operations with fissile - material stops fissile material processing activities and movement of fissile material. The design of the system, three detector modules per cluster, provides protection for criticality events even with partial losses of required equipment. The alarm signal is provided by sounding building horns which sound upon a signal from any cluster, and by sounding in some locations a local horn associated with each individual l. cluster. The building horns for C-709 and C-710 are configured in two separate networks, either of which - can independently sound the required evacuation signal. The building horn configuration in C-709 and C- . 710 allows the CAAS for those buildings to remain operable even when one of the independent horn networks is temporarily out of service. Dunng the 4 hours allowed to restore audibility, an alternate means of criticality accident alarm notification is available. Providing another means of coverage for the area in g l the event of inaudibility will establish protection on a temporary basis until system operability is restored. 4 4 The nitrogen bottles which backup plant air for the local cluster horns provide for 120 seconds of horn actuation when at their minimum acceptable pressure of 900 psig (where applicable). l - De semiannual surveillance of the CAAS, local cluster horns and building horns consists of placing the e cluster in the test mode, and manually causing two detector modules to generate radiation readings above the alarm setpoint. De cluster electronics determmes that this meets the high radiation alarm criteria and propagates a high radiation alarm signal to the rest of the system. This signal activates the high radiation alarm light and bell in C-300, causes the local cluster horn to sound (where applicable) and activates the l - building CAAS horns and lights. Each horn and light is qualitatively verified to be operating. This test P is a horn and light functional test and each module combination is tested to generate the high radiation signal. [SAR 3.15.7.1] j ~ f L h 'k; j' I 2.4-12

= GDP98-0105 Page 1 of 4 United States Enrichment Corporation (USEC) Proposed Certificate Amendment Request Criticality Accident A' arm System Clusters in C-710 and C-720 i Significance Determination l l The United States Enrichment Corporation (USEC) has reviewed the proposed changes associated with this certificate amendment request and provides the following Significance determination for consideration. l

1. No Significant Decrease in the Effectiveness of the Plant's Safety. Safeguards or Security

) l Procrams The Technical Safety Requirements (TSRs) are not addressed in plant safety, safeguards or security programs contained in Volume 3 of the Application for United States Nuclear Regulatory Commission Certification for the Paducah Gaseous Diffusion Plant. Therefore, the effectiveness of these programs is unaffected by these changes.

2. No Significant Change to Any Conditions to the Certificate of Compliance None of the Conditions to the Certificate of Compliance for operation of the Paducah Gaseous j

Diffusion Plants specifically address required actions in Technical Safety Requirements. Thus, the proposed changes have no impact on any Condition to the Certificate of Compliance.

3. No Significant Change to Any Condition of the Approved Comoliance Plan I

The changes requestes m TSR 2.6A.1 results from the implementation of commitments made in Compliance Plan Issue 8. The revision to this TSR reflect the modifications required to comply with the Plan ofAction for this Compliance Plan Issue which is to upgrade the Criticality Accident Alarm System for Building C-710. In addition, TSR 2.6.4.1 is revised to reflect the C-720 buildings which could contain greater than 700 grams of 2nU enriched to a 1.0 wt %. Therefore, there is no significat change to any condition of the approved Compliance Plan.

4. No Significant Increase in the Probability of Occurrence or Consequences of Previously i

Evaluated Accidents TSR 2.6.4.1 is being revised to reflect the modifications being implemented as a result of Compliance Plan Issue 8, which involves upgrading the CAAS system for building C-710. The i new C-710 CAAS uses the same components and operational methodology as existing system components. The new system uses additional, permanent gamma radiation detection clusters to provide improved detection coverage. The new alarm network is configured as two separate groups of alarm horns which can independently provide adequate audible alarm coverage for evacuation of personnel in and around C-710. In all aspects the new system is equal to or better l than the existing CAAS for this facility. Furthermore, the Criticality Accident Alarm System

GDP98-0105 I Page 2 of 4 United States Enrichment Corporation (USEC) Proposed Certificate Amendment Request l Criticality Accident Alarm System Clusters in C-710 and C-720 Significance Determination is utilized to mitigate the consequences to onsite workers and has no impact on the probability of occurrence of an accident. In addition, TSR 2.6.4.1 is revised to reflect the C-720 buMings which could contain greater than 700 grams of "U enriched to 2 1.0 wt %. This change reflects those areas which are required to have Criticality Accident Alarm System coverage and has no impact on previously evaluated accidents. Therefore, there is no significant increase in the probability of occurrence or consequences of previously evaluated accidents.

5. No New or Different Tyne of Accident TSR 2.6.4.1 is being revised to reflect the modifications being implemented as a result of Compliance Plan Issue 8, which involves upgrading the CAAS system for building C-710. The new C-710 CAAS uses the same components and operational methodology as existing system components. The new system uses additional, pennanent gamma radiation detection clusters to provide improved detection coverage. The new alarm network is configured as two separate groups of alarm homs which can independently provide adequate audible alarm coverage for evacuation of personnel in and around C-710. In all aspects the new system is equal to or better than the existing CAAS for this facility. In addition, TSR 2.6.4.1 is revised to reflect the C-720 buildings which could contain greater than 700 grams of 2"U enriched to z 1.0 wt %. The CAAS system is utilized to mitigate the consequences of an accident and is not assumed to be an accident initiator. Therefore, this TSR change does not create any new or different type of accidents.

6. No Significant Reduction in Margins of Safety TSR 2.6.4.1 is being revised to reflect the modifications being implemented as a result of Compliance Plan Issue 8, which involves upgrading the CAAS system for building C-710. The new C-710 CAAS uses the same components and operational methodology as existing system components. The new system uses additional, permanent gamma radiation detection clusters to provide improved detection coverage. The new alarm network is configured as two separate groups of alarm homs which can independently provide adequate audible alarm coverage for evacuation ofpersonnel in and around C-710. In all aspects the new system is equal to or better than the existing CAAS for this facility. In addition, TSR 2.6.4.1 is revised to reflect the C-720 buildings which could contain greater than 700 grams of 2"U enriched to z 1.0 wt %. This change reflects those areas which are required to have Criticality Accident Alarm System coverage. As such, there is no significant reduction in the Margins of Safety, t

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i l j l GDP98-0105 Page 3 of 4 United States Enrichment Corporation (USEC) l Proposed Certificate Amendment Request Criticality Accident Alarm System Clusters in C-710 and C-720 Significance Determination

7. No Significant Decrease in the Effectiveness of Any Procram or Plan Contained in the Certificate Application The requirements ofTSR 2.6.4.1 are not specifically addressed in any of the plans or programs contained in Volume 3 e f the Certification Application for the Paducah Gr.seous Diffusion Plant.

Therefore, the changes to these TSRs discussed above do not reduce the effectiveness of any program or plan contained in the Certification Application.

8. The Prooosed Changes do not Result in Undue Risk to 1) Public Health and Safety. 2) Common Defense and Security. and 3) the Environment TSR 2.6.4.1 is being revised to reflect the modifications being implemented as a result of Compliance Plan Issue 8, which involves upgrading the CAAS system for building C-710. In all aspects the new system is equal to or better than the existing CAAS for this facility. In addition, TSR 2.6.4.1 is revised to reflect the C-720 buildings which could contain greater than 700 grams of 2"U enriched to a 1.0 wt %. This change reflects those areas which are required to have Criticality Accident Alarm System coverage. These changes enhance the CAAS system.

As such, these changes do not result in undue risk to public health and safety. In addition, these TSR changes have no impact on plant effluents or on the programs and plans in place to implement physical security. Consequently, these proposed changes only enhance safety and pose no undue risk to the environment or to common defense and security.

9. No Change in the Tvoes or Significant Increase in the Amounts of Any Effluents that May be Released Offsite This change has no affect on the generation or disposition of effluents. Therefore, this change does not change the type or amounts of effluents that may be released offsite.

10. No Significant Increase in Individual or Cumulative Occupational Radiation Exoosure The proposed changes involve revision of the existing CAAS TSRs. The CAAS is not used to control or minimize occupational radiation exposures or to comply with 10 CFR 20 requirements. Therefore, this change does not relate to controls used to minimize occupational radiation exposures.

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~ GDP98-0105 l Page 4 of 4 I United States Enrichment Corporation (USEC) I Proposed Certificate Amendment Request Criticality Accident Alarm System Clusters in C-710 and C-720 l Significance Determination

11. No Significant Constmetion Imnact This TS.R change does not involve a plant modification. Therefore, there is no significant construction impact resulting from this TSR change.

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12. No Signifg; ant Increase in the Potential for. or Radiological or Chemical Consequences from.

Previously Analyzed Accidents The proposed TSR changes ensure that the TSRs adequately address the modified plant configuration required by the Compliance Plan. In addition, this TSR change also reflects the C-720 buildings which are required to have Criticality Accident Alarm Systems due to the amount of fissile material which could be present within these buildings. The Criticality Accident Alarm System is utilized to mitigate the consequences of criticality accidents. These changes will ensure that adequate CAAS coverage is provided to alert personnel of a criticality and to notify those personnel of the need to evacuate. These changes do not increase the potential for, or radiological or chemical consequences from, previcusly analyzed accidents. l l ) I >.}}