ML20199H305
| ML20199H305 | |
| Person / Time | |
|---|---|
| Site: | Paducah Gaseous Diffusion Plant, Portsmouth Gaseous Diffusion Plant |
| Issue date: | 01/19/1999 |
| From: | UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | |
| Shared Package | |
| ML20199H173 | List: |
| References | |
| NUDOCS 9901250161 | |
| Download: ML20199H305 (26) | |
Text
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SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX 3.5 WITHDRAWAL FACILITIES 3.5.1 Withdrawal Systems TO BE PROVIDED M TER 3.5.1.1 UF Withdrawal Primary System 6
TO BE PROVIDED MTER 3.5.1.2 Process System Pressure and Temperature Monitoring TO BE PROVIDED MTER 3.5.1.3 Butter System TO BE PROVIDED MTER 3.5.1.4 Seal Feed and Exhaust System TO BEPROVIDED MTER 3.5.1.5 Lube Oil System TO BE PROYlDED UTER 3.5.1.6 Lube Oil System Monitoring and Alarms TO BE PROVIDED U TER 3.5.1.7 Coolant System TO BE PROVIDED U TER 3.5.1.8 -
Coolant High Pressure Relief System TO BE PROVIDED U TER 3.5-1 9901250161 990119 5
PDR ADOCK 07007001!
C PDR
SA R-PGDP PROPOSED-GRADE 1 October 28,1998 l
RAC 98C-XXXX 1
1 3.5.1.9 Coolant System Monitoring Instrumentation TO BE PROVIDED MTER 3.5.1.10 Condenser Coolant Overpressure Relief 1
TO BE PROVIDED M TER 1
3.5.1.11 Outleakage Detection TO BE PROVIDED MTER 3.5.1.12 UF Release Detection System 6
TO BE PROVIDED UTER 3.5.1.13 Withdrawal Station Isolation System I
The Product (C-310 Building) and Tails (C-315 Building) Withdrawal Facilities are equipped J
with a UF release detection and isolation system for the withdrawal positions. Consequences of a UF6 6
release from a withdrawal facility pigtail failure are mitigated by the Withdrawal Station Isolation j
System as discussed in Sections 4.3.2.2.4 and 4.3.2.2.11. In the event of a pigtail failure, the system is I
utilized to isolate the withdrawal position to minimize the amount of UF6 released. This system is classified as important to safety as described in Section 3.10.
3.5.1.13.1 Safety Function Radiological /Nonradiological. The Withdrawal Station isolation System is capable ofisolating the withdrawal station to prevent exceeding the radiological /nonradiological Evaluation Guidelines (EGs) for the Evaluation Basis Event (EBE) category.
Criticality. The Withdrawal Station Isolation System, in the Product Withdrawal Facility, isolates product cylinders to preclude further releases of fissile material. Released UF. reacts with moisture in the air to form UO F. which further absorbs moisture from the air. UO F and water in 2 2 2 2 nonfavorable geometry have the potential to achieve criticality. This active engineered feature does not include the manual isolation system.
3.5.1.13.2 Functional Requirements The Withdrawal Station Isolation System includes: (1) automatic UF detection and isolation; 6
and (2) manual isolation. The system is designed in accordance with the following functional requirements to ensure the capability to accomplish the required safety functions:
s 3.5-2
1 SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX The system is capable of accomplishing the required safety function independent of the plant air supply.
l The system is capable of accomplishing the required safety function independent of the
)
normal AC power supply to the facility.
1 The automatic detection and isolation ponion of the system is capable of detecting UF6 outleakage and isolating the withdrawal position pigtail at both ends.
The automatic detection and isolation portion of the system closes the cylinder valve and isolates the withdrawal header for the station within 30 seconds after acmation of the ionization detectors.
The manual isolation portion of the system is capable of isolating the liquid source and is accessible outside the withdrawal room.
3.5.1.13.3
System Description
The Withdrawal Station isolation System, in the Product (C-310 Building) and Tails (C-315 Building) Withdrawal Facilities, consists of two low-voltage detectors. The low-voltage UF6 release j
detectors are located above each withdrawal position, one detector located at the ceiling and one detector located directly above each withdrawal drain position and are discussed in more detail in Section 3.7.3.3.
In addition, the system consists of UF6 line isolation valves (e.g. cylinder valve and liquid drain block valves), cylinder valve motor and closure assembly, air supply piping, associated circuitry (including alarms and indicator lights), manual isolation switches, system suppon power, a backup nitrogen supply, and solenoid valves necessary to operate the liquid drain block valves. The Withdrawal Station Isolation System operates off the plant 120-VAC power system, which supplies 24-VDC to the detectors and initiates alarms. Figure 3.5.1.13-1 shows a typical Withdrawal Station Isolation System. A high-voltage UF6 release detection system, located adjacent to the low-voltage detectors, activates alarms and is discussed in more detail in Section 3.7.3.1.3.
Activation of a low-voltage detector above any drain position pigtail will initiate isolation of that withdrawal position causing the following actions to occur: (1) closes the two liquid drain block valves located between the accumulators and the withdrawal pigtail; (2) closes the withdrawal cylinder valve; and (3) initiates alarms in the withdrawal area and in the respective Area Control Rooms (ACRs).
Activation of any low-voltage detector at the withdrawal room ceiling will only close the liquid drain block valves for all withdrawal positions in the withdrawal room and initiate an alarm in the respective ACR.
The UF6 line isolation valves associated with the Withdrawal Station isolation System include air-operated liquid drain block valves (spring actuated / fail closed), cylinder valve (with an air-operated / motor driven closure assembly), and miscellaneous valves associated with the building 3.5-3
SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX air /aitrogen systems that support withdrawal isolation.
The liquid drain block valves are diaphragm-actuated valves that require air to open ar.d springs to close and are fail-safe. The cylinder valve is a manual valve that is equipped with an air-ope ated/ motor-driven closure assembly. The air-control solenoid for the cylinder valve closure assembly is deenergized during activation of the isolation system. Air is then supplied to the cylinder valve closure motor, which closes the cylinder valve, isolating the UF cylinder from the withdrawal position. A backup nitrogen system, provided for the 6
cylinder valve closure assembly, activates upon failure of the plant air system. The evacuation block valves are not part of the Withdrawal Station Isolation System safety system boundary but they provide defense in depth to minimize the consequences of a failure in the withdrawal pigtail. The air-operated valves associated with the evacuation line open, allowing UF to be evacuated from the pigtail to the 6
evacuation header during automatic activation of the isolation system as described in Section 3.5.1.1.
If the automatic Withdrawal Station Isolation System fails to activate due to a failure in the system, liquid drain block valves can be closed with controls located outside the withdrawal room, in the ACR, or in the Central Control Facility (CCF). The pushbutton located immediately outside the withdrawal area closes the liquid drain block valves (those associated with the Withdrawal Station isolation System) and the cylinder valve in all withdrawal positions within the building. The ACR and CCF have separate manual isolation pushbuttons or switches for each withdrawal position within the Product and Tails withdrawal area. These buttons also close the Withdrawal Station Isolation System liquid drain block valves and the cylinder valve.
3.5.1.13.4 System Evaluation The Withdrawal Station Isolation System was evaluated to assess its ability to accomplish its required safety function. In addition, a qualitative fault tree analysis was performed to determine the system's capability to accomplish its safety function. The results of these evaluations are provided in this section.
Safety function analysis. The safety function required of this section is to limit the release of UF and its reaction products to less than the radiological /nonradiological EGs for an EBE. A review of 6
the withdrawal facility operations determined that the bounding event for this system is pigtail failure at a withdrawal position, described in Section 4.3.2.2.11. In order for the Withdrawal Station Isolation System to accomplish its safety function, the system must detect a UF release at the withdrawal position 6
and close the UF line isolation valves before the release exceeds these guidelines. In addition, manual 6
isolation must be capable ofisolating the withdrawal station.
The hazard and accident analyses assumed that a significant UF release (see Section 4.3.2.2.11) 6 at a withdrawal position would be detected by the withdrawal position detectors within 15 seconds and the liquid source is automatically isolated (i.e., the UF6 line isolation valves close, isolating the pigtail from the accumulator and the cylinder) within 30 seconds after initiation to close. This event was evaluated in Section 4.3.2.2.11 and the consequences were determined to be below the applicable EGs.
3.5-4 f
i 1
SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX The manual isolation capability provides operational flexibility for conditions where the automatic detection capability is out of service. In order to assure a timely initiation of the system, continual surveillance of the withdrawal room is provided for quick detection of any releases. The environmental conditions associated with this circuitry are not significantly different, other than the
" smoke" generated from the reaction of UF and the moist air, from normal operation due to the short 6
response time.
Based on this analysis, the Withdrawal Station Isolation System will prevent exceeding the radiological and nonradiological EGs for the most limiting UF6 primary system integrity failure at a withdrawal position provided the system automatically closes the UF6 line isolation valves within 45 seconds after the release occurs. Events where the cylinder valve cannot be closed due to the event are addressed in Section 4.3.2.2.11.
Qualitative fault tree analysis. In addition to the safety function analysis, a qualitative fault tree analysis of the Withdrawal Station isolation System was performed in accordance with Section 4.3.1.1.3 to evaluate the capability of the system to accomplish its required safety function. The ability of the system to meet the functional requirements is described below.
As indicated in the functional requirements, the system is required to accomplish the required safety function independent of plant air and electrical supply. The system configuration can accomplish its required safety function independent of the plant air and electrical distribution system including the nitrogen bottle backup to the plant air system (valve closures). These nitrogen bottle backups are considered part of this system and are required to be tested periodically to verify their operability.
Therefore, the system can accomplish its required safety function independent of plant air.
The UF detectors are required for the automatic detection system. Should these detectors be 6
determined as inoperable, a continuous smoke watch is instituted to allow for quick detection to initiate manual isolation.
In addition to the functional requirements associated with the loss of electric power and air, the automatic operation of the system is required to isolate equipment within 30 seconds after actuation of the UF detectors. The analysis assumes the detectors will actuate within 15 seconds after a significant 6
release.
Past operational history with the UF detectors has indicated a response time ofless than 15 6
seconds for any significant release (see Section 4.3.2.2.11) as a result of the amount of " smoke" generated by the release. Valve closure time is verified periodically by surveillance tests to ensure the 30-second closure time is met. Therefore, the system can accomplish the required automatic detection and isolation.
The location of the manual isolation is outside the immediate area of the release with a closed door providing limited protection for the operating personnel. Therefore, the manual isolation functional requirement is also achieved by the system configuration.
3.5-5 I
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SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX l
Based on the capability to detect and isolate a release and the various controls associated with the system, the Withdrawal Station Isolation System can meet its functional requirements.
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3.5.1.14 HEPA Exhaust System TO BEPROVIDED UTER 3.5.1.15 Assay Monitoring Syttem TO BE PROVIDED MTER 3.5.1.16 Auxiliary Backup Power System TO BE PROVIDED U TER 3.5.1.17 DC Power Distribution System TO BE PROVIDED UTER 3.5.1.18 Support Systems 3.5.1.18.1 Electrical System The 120-VAC power to operate the Withdrawal Station isolation System is supplied from 480-VAC power at the motor control center. Supplied 120-VAC power is then used to develop the 24-VDC power supply for the UF6 release detection circuit. A separate 120-VAC power circuit feeds the solenoid valves that actuate the liquid drain block valves, the cylinder valve closure assembly, and the l
evacuation block valves. The liquid drain block valves and the evacuation block valves are designed to close (i.e., fail-safe) upon loss of 120-VAC power. The cylinder valve is designed to close (by activation of the nitrogen backup system) upon loss of power. There are no backup power systems, since the liquid drain block valves (those associated with the Withdrawal Station Isolation System) and the cylinder valve fail closed on loss of power.
3.5.1.18.2 Plant Air System Nominal 85-psig air is supplied from the plant air system and provides the motive power for the l
cylinder valve closure assembly. The cylinder valve closure assembly is also provided with a nitrogen j
backup system, On loss of plant air or low plant air pressure, a pressure switch on the air supply line l
actuates to open a solenoid valve making nitrogen available through the air supply line. The nitrogen is l?
supplied from a portable tank in sufhcient quantity and pressure to completely close the cylinder valve l
within 30 seconds. The nitrogen supply is isolated from the plant air system by a check valve that I
i prevents loss of nitrogen pressure. The liquid drain block valves require air to open and are spring 3.5-6 L
1
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i SAR-PGDP PROPOSED-GRADE 1 October 28,1998 i
RAC 98C-XXXX t
closed. Therefore, on loss of plant air, the valves fail in the closed position, isolating the withdrawal position from its liquid source.
3.5.1.19 System Operation 3.5.1.19.1 Operational Modes The Withdrawal Station isolation System is designed to be orierable during the Withdrawal i
Mode as defined in the Technical Safety Requirements (TSR). Automatic operation of the system isolates equipment within 30 seconds after actuation of the UF detectors.
6 Detectors are required for the automatic actuation of the Withdrawal Station isolation System.
In the event that the UF6 release detection portion of the system fails, a continuous smoke watch is established in the affected area. If an operator detects (visually or through smell) a UF release, he/she 6
can initiate isolation of the withdrawal positions by actuating the manual isolation pushbuttons/ switches.
In addition, operators in the CCF can initiate isolation of all withdrawal stations at each facility by actuating hand switches.
During off-normal operating conditions, loss of plant air or loss of AC power, the liquid drain block valves fail in the closed position. The cylinder valve fails closed with either the loss of plant air or AC power. A backup nitrogen supply is provided in the event that the air supply fails.
3.5.1.19.2 Inst ru mentation, Con trols, and Alarms Alarms indicating Withdrawal Station Isolation System activation include indicating lights and j
audible devices located as follows:
i local panel or withdrawal area (C-310 and C-315 Buildings) -
lights and horn e
ACR(C-310 C-315,C-331 Buildings) lights and horn e
CCF (C-300 Building) lights e
3.5.1.20 Maintenance and Testing Requirements TO BE PROVIDED LA TER 3.5.1.21 Administrative Controls In addition to the Administrative Controls in 4.3.2.2.4 and 4.3.2.2.11, and those controls covered j
by programs and plans, the following ensure safe operation of the Withdrawal Station Isolation System.
i 3.5-7 j
SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX 4
Inspecting cylinders prior to filling for physical defects.
+
Cylinder handling equipment is inspected daily (when used) for obvious defects associated with the lifting system and potential fuel / hydraulic leaks.
No cylinder /similar weight load shall be moved over a cylinder containing liquid UF -
6 Only approved cylinder handling equipment will be used by qualified operators for e
maneuvering cylinders and other heavy loads.
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SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX 1
3.7.5 Non-Radiological Chemical Systems The non-radiological chemical systems produce, store, or distribute chemicals for use in the cascade process or support systems. The chemicals included in this group are fluorine (F ), chlorine 2
(Cl ), hydrogen fluoride (IIF), and chlorine trifluoride (ClF ). F, and/or a mixture of F and CIF, can 2
3 2
2 3
be used in the cascade process for drying or unplugging treatments, liF is the feed material used to produce F, and Cl i
2 s used in sanitary water treatment and sewage treatment for microbiological 2
l control. Process hazards analyses have been prepared to evaluate the risks associated with the operation of these systems and to determine the controls necessary for their safe operation. Controls established at PORTS for chemical safety are described in Section 5.6.
3.7.5.1 Fluorine Generation System Fluorine gas (F ), which is used for cascade equipment maintenance, is produced in the Fluorine 2
Generation System using HF gas as the feed material. IIF cylinders are delivered to the Plant by commercial motor freight. The HF cylinders are stored and the F generating equipment is housed in the 2
X-342A Feed Vaporization and Fluorine Generation Building. Fluorine generated in the system is stored in tanks in the X-342B Fluorine Storage Building. From the storage tanks, the F is piped throughout the 2
cascade and other support facilities. The Fluorine Generation System consists ofliF cylinders, fluorine generators, fluorine storage tanks, associated piping and equipment, gas release detectors, and gas release detection alarm components. The Fluorine Generation System portion of the nonradiological chemical systems boundaries are defined in Table 3.10-2.
The X-342A Building, located in the north-central part of the Plant, occupies the southeast portion of the X-344A/342A complex. X-342A is a single-story, slab-on-grade, steel frame building with transite board siding. In addition to the building ventilation system, a dedicated ventilation system is provided for the Fiuorine Generation Room and the NaF Trap Room. IIF detectors with automatic alarms, as well as manually-operated gas release alarms, are located in the F2 generation areas. The building is equipped with emergency showers and eye baths, fire alarm boxes, and portable extinguishers in addition to the F system, UF cylinder sampling equipment is located in X-342A. A 2
6 separate high-bay part of the building contains two autoclaves with scales, cranes, and other associated UF feed and sampling equipment. The F process areas are separated from the UF areas by concrete 6
2 6
block and transite walls. The two F headers from the storage tanks in X-342B are routed through the 2
UF6 high bay, and the llF cylinders are moved through the high bay area in route to the liF storage room. No other interactions occur between the two systems.
The X-342B Fluorine Storage Building is located just east of X-342A. It is a single story, slab-on-grade, steel beam structure with concrete block and transite board siding. A manually actuated exhaust fan is used to increase the ventilation rate when maintenance is performed in the building. An evacuation air jet is available for use in emptying the storage system for maintenance. The building is 3.7-1
SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX equipped with IIF vapor detectors and a fire alarm pull box. No processes, other than the F2 storage tanks and associated piping, are located in the building.
The IIF cylinders are owned by PORTS and are filled off-site by commercial vendors. Cylinders comply with Department of Transportation specifications. The condition of the cylinders and cylinder valves are noted in the receipt inspection at X-746. Each cylinder has a capacity of 1,000 lb ofIIF; however, an 850-lb fill limit is imposed by PORTS to maintain a safety factor.
Plant systems that support the Fluorine Generation System are described in Sect. 3.7.5.4 3.7.5.1.1 Chemical Safety Function ne non-radiological chemical systems described in this section are important to safety. They are required to perform the following chemical safety functions:
Maintain integrity to the process, which minimizes the potential for releasing toxic gas into the atmosphere.
Ensure that the fluorine primary system is relieved on high pressure to minimize the potential for a failure of the primary system integrity.
Detect releases from the primary system and provide a local alarm indication of the release.
3.7.5.1.2 Functional Requirements The non-radiological chemical systems shall be designed and maintained for the intended service. The fluorine system pressure relief system shall be available on storage tanks that contain fluorine at pressures greater than atmospheric. The system shall actuate at or below the MAWP for the fluorine storage tank and discharge to an elevated stack. The toxic gas leakage detection system shall be designed to provide local alarm indications upon detection of releases from the primary system.
l 3.7.5.1.3 System Description 3.7.5.1.3.1 Equipment Descriptions and Functions 1
r l
Fluorine is generated from anhydrous hydrogen fluoride. A typical HF delivery to PORTS l
consists of up to four cylinders, each containing up to 850 lb of IIF, delivered to the plant site via commercial motor freight in protective shipping baskets. Cylinder valves are protected by steel valve covers that are hinged to allow access to the valves. The cylinders are delivered to the X-746 Materials Receiving and Inspection Facility where they are unloaded from the delivery truck, visually inspected, and placed in an adjacent storage area. When needed, up to four cylinders are moved, in their shipping baskets, to the X-342A Feed Vaporization and Fluorine Generation Building. At X-342A, the cylinders 3.7-2
1 I
l SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX i
are removed from the shipping baskets by an overhead crane and placed onto wheeled dollies. The cylinders are then inspected and moved to the IIF Storage Room where they are secured in place with chains. The X-342A liF Storage Room is equipped to store up to 12 full cylinders.
The primary components of the Fluorine Generation System consist of a heated cabinet in the Vaporizer Room, F2 generators, a surge drum, sodium fluoride traps, sintered metal fihers, F2 compressors, F storage tanks, and associated control valves and piping. (Fig. 3.7-x) 2 The heated cabinet is equipped with an IIF detector and an air exhaust line. The cabinet walls are insulated, and interior heat is supplied by electric heaters. An airjet is provided to purge the cabinet prior to opening the access doors. Gas purged from the cabinet is exhausted outside the building through an elevated stack. The cabinet contains a mounting saddle that accommodates two IIF cylinders. A slot in the IIF cylinder skirt must be aligned with a peg on the mounting saddle. Otherwise, the system pigtail cannot physically be connected to the cylinder. The cylinders are secured to the saddles with chains.
Four fluorine generators, each capable of producing up to 5 lb of F per hour, are located in the 2
Generator Room. The primary components of the generators are the rectangular steel outer cell body, the electrolyte, the electrodes, the Monel inner vessel, the hydrogen collector, and the fluorine collector. The outer cell body serves as a water jacket that allows the electrolyte solution to be heated with steam or cooled with water. 11F is fed from the feed cylinder at a rate sufficient to produce the desired F2 generation rate. A typical IIF feed rate is about 30 lb per hour. The generators produce F by applying a 2
j high amperage DC current through the electrolyte in the presence of the HF feed gas. The net result of the reaction is the decomposition of IIF to produce F2 at the anode and 112 at the cathode. A gas separator skirt between the electrodes prevents mixing of the 11 and F gases.
2 2
Electrostatic precipitators are installed in the F outlet piping from each fluorine generator to 2
collect any electrolyte mist or dust carryover before it can enter the system piping. An electrolyte entrainment separator is installed in the 11 outlet piping for the same purpose.
2 From the generators, the F2 flows to a 110 ft3 surge drum in the Generator Room that helps to control the flow to the storage tanks.. The maximum operating pressure for the tank is 5 psig and the maximum operating temperature is 180 F. At 5 psig and 80 F, the surge drum contains approximately 14 lb of F -
2 In the event that high pressure develops in the system, F2 can be manually vented to the atmosphere through an elevated stack.11 gas, which is a byproduct of F generation, is normally routed 2
2 through a flame arrestor and discharged to the atmosphere through an elevated stack.
From the surge drum, F2 flows through sodium fluoride (NaF) traps and sintered metal filters located in the Trap Room. The traps and the filters are provided to remove residual liF and particulate, respectively, from the product stream. The system contains four NaF traps, any two of which can be operated in parallel. The medium in the traps is hardened NaF pellets. The system has two sintered metal filters with Monel tilter elements---one normally on-line and one available as a backup.
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3.7-3
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i SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX
+
Multi-diaphragm compressors are used to pump the F to the storage tanks in X-342B. These 2
i compressors provide multiple barriers between the F gas and the pump oil to prevent contamination of 2
the F Leakage of F or oil through any diaphragm is detected and annunciated by audible and visual 2
2 alarms located in the Control Room. Two compressors are installed in parallel. They are normally l
operated one at a time.
2 nto the three 1,000 ft3 F2 storage tanks located in the X-342B The compressors pump F i
Fluorine Storage Building. At a maximum normal operating pressure of 45 psig, each tank contains about 430 lb of F at 30 *F. The carbon steel tanks have a maximum allowable working pressure of 194 2
l l
psig and a maximum operating temperature 250 *F. Each tank is equipped with a relief device consisting l
of a pair of rupture discs with a nitrogen buffer in the piping between the discs. The discs are designed to rupture at 85 psig. The buffered zone is instrumented to detect and annunciate pressure changes. In the event that both discs rupture, excess system pressure is vented outside the building through a 30-fl stack.
Valves in X-342B are equipped with handles on the operators so the valves can be operated from outside l
the building. Instrumentation for this portion of the system is also mounted on the outside wall of the building.
From the storage tanks, F flows to buildings X-330 and X-333 through the black-iron header or 2
the process gas (PG) return header. A metering station monitors the How of F to the PG return header.
2 i
Double valves are used for equipment isolation to reduce the likelihood of leaks to the environment l
during maintenance (see Fig 3.7-x).
The black-iron header normally operates at a pressure of
)
l approximately 5 psig, which is maintained by a control valve in X-3428.
l Ilydrogen fluoride leak detectors are located in the Building X-342A IIF Storage Room; the Vaporizer Room above the vaporizer, and in the heated cabinet. IIF detectors are also located above l
each of the Duorine storage tanks in the X-342B Buik6ng. The detectors are commercially available ionization-type smoke detectors. These detectors are suitable for F2 eaks because the reaction of l
Duorine and moisture in the air rapidly produces liF, whose characteristic white smoke is readily detected by ionization detectors. Actuation of the detectors results in alarms locally and in the ACR.
Refer to Section 3.7.3.4 for a description of detector system components.
3.7.5.1.3.2 Materials of Construction Gaseous liF and F are not extremely corrosive to piping. Carbon steel, stainless steel, Monel or 2
copper are suitable materials of construction for use when no moisture is present. System piping is schedule 80 carbon steel, tanks are heavy gauge carbon steel, pigtails are copper, and valves are Monel l
or stainless steel.
3.7.5.1.3.3 Chemistry Requirements The following chemicals are used or produced in the F Generation System:
2 Potassium binuoride - primary electrolyte used in the F generators.
j 2
3.7-4
I SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX Lithium Huoride-electrolyte additive used in the F generators.
e 2
liydrogen nuoride-feed material used to produce F -
e 2
Fluorine - primary system product.
Soda ash (Na2CO )- used to neutralize equipment contaminated by contact with F or liF.
3 2
Slaked lime (Ca(OH)2)- used to trap free Huorides present in the soda ash.
flydrogen - a byproduct of F generation.
e 2
The hazards associated with these chemicals are considered to be standard industrial hazards.
3.7.5.1.4 System Evaluation The non-radiological chemical systems are required to prevent releases of toxic gas to the atmosphere during normal operations. This safety function is accomplished by retaining system integrity during normal operations and upset events. The design requirements ensure that the primary systems can withstand the operating conditions assumed in the accident analysis and are appropriate for the chemical being used.
Primary Ouorine system integrity is protected by minimizing the potential for a release of Ouorine from a line at the storage tank at X-342B caused by overpressurization. A release of Ouorine from a ruptured primary system could result in an uncontrolled release at ground level. The system accomplishes its safety function by relieving excessive pressure to the atmosphere through an elevated stack.
Toxic gas detectors are located in areas where a signincant release of toxic gas could occur. The required safety action is to detect a release and provide local indications of the release. The safety action is accomplished by having detectors appropriate to the toxic gas present (chlorine, nuorine, etc.) and providing both audible and visual alarm indications in X-342-A and X-342-B. The system provides on-site protection for personnel by detecting a release and alerting personnel to immediately evacuate the area.
3.7.5.2 Chlorine Trinuoride later 3.7.5.3 Chlorine System later 3.7-5
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SAR-PORTS PROPOSED-GRADE 2 October 28.1998 i
i RAC 98X-XXXX 1
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3.7.5.4 Support Systems l
3.7.5.4.1 DC Electrical System IX' electrical power for the F generators comes from two selenium diode rectiners, each rated 2
at 6,000 amps at 60 V. The rectiDers are located in a room adjacent to the F generators.
2 3.7.5.4.2 AC Electrical System Electrical power from the plant 120 VAC system supplies the Guorine release detectors and j
l 3.7.5.4.3 Plant Air System Plant air is used to purge HF system pigtails, F tanks, and other equipment for maintenance.
2 Plant air also provides motive power for pneumatic valve actuators.
3.7.5.4.4 Plant Steam System Plant steam is piped to the Fluorine Generator water jackets to keep the electrolyte warm and prevent solidiGcation during maintenance.
3.7.5.4.5 Fluorine Generator Cooling Water Cooling Water is supplied to the F2 generator water jackets to cool the generator during operation. The cooling water is a closed loop, recirculating system with a collection drum and two recirculating pumps located in the F Generator Room. Plant sanitary water provides makeup as needed.
2 3.7.5.4.6 Ventilation System Room exhaust ventilation in the Generator Room and the Trap Room is provided by a dedicated system. The roof-mounted exhaust fan operates constantly when F generation is in progress. An alarm 2
actuates in the Control Room if the exhaust system stops. The Control Room is maintained at a positive pressure relative to the operating areas to prevent any inleakage of F. The X-342B Building is open to 2
the environment. A manually actuated exhaust fan in the building is used when maintenance is being performed.
3.7-6 1
i
SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX 3.7.5.5 System Operation 3.7.5.5.1 Operational Modes Operational modes for the toxic gas systems as defined in the Plant Operational Safety Analysis are:
feed of DOT cylinders into process, e
storage / distribution of toxic gas, and e
out of operation.
The cylinder feed mode applies from the time the cylinder cap is removed to initiate the feed process until disconnection of the feed cylinder from the system is complete. The storage mode applies any time gas storage takes place, in tanks or cylinders. The system is "out of operation" when the valves connecting the system to any supply of toxic gas are closed, and the system is purged of the toxic gas such that the PrilA screening thresholds are not exceeded.
3.7.5.5.2 Instrumentation, Controls, and Alarms The primary safety concern for the Fluorine Generation System is personnel exposure to a large leak of fluorine or IIF gas. Consequently, operational instrumentation, controls, and alarms are designed to protect the system's confinement integrity.
The Fluorine Generation System is equipped with the means for emergency shutdown to protect the F generating equipment and to isolate the piping and the storage tanks. The electrical circuit that 2
powers the shutdown system is activated by any of several alarms on the control panel in the X-342A Fluorine Control Room or by either of two manual switches (on the control panel and on the outside west wall of the fluorine generator room) as follows:
high pressure in an 11 or F cell rectifier cooling fan failure e
2 2
high differential pressure in an 112 or F cell rectifier high temperature e
2 e
header high difTerential pressure between F and 112
- F2 compressor shutdown (high F2 discharge e
2 pressure) rectifier power overload manual switch in the Control Room e
e rectifier cooling water pump failure manual switch outside of the west wall of the e
e F generator room.
2 Other key operational instrumentation for the system includes a microprocessor-based controller that maintains an internal temperature of 180 F, or less, in the liF cylinder heated cabinet. The 3.7-7
SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX controller actuates audible and visual alanns in the X-342A Fluorine Control Room and shuts off the heaters if the internal cabinet temperature exceeds the high temperature setpoint or if the pressure in the system exceeds the high pressure setpoint.
An indicating pressure transmitter is located on the main liF feed line. This instrument indicates pressure locally and also transmits a signal to a digital indicator and alarm module in the Generator Room. System pressure is monitored by pressure switches on the Duorine and hydrogen headers. The switches activate an audible alarm and a light iu the X-342A Fluorine Control Room if pressure exceeds the setpoint.
A control valve located upstream of the NaF traps protects the F2 generating equipment from high system pressure. In the event that pressure in the F distribution headers exceeds the setpoint, the 2
valve automatically closes. A second control valve located downstream of the F compressors closes on 2
compressor shutdown to prevent distribution system pressure from reaching the F2 generating equipment.
Each of the two cylinder pigtail connections has a pneumatic indicator located on the liF piping above the cabinet. A third pressure indicator is located in the main llF feed line. This indicator produces a digital pressure readout in the X-342A Fluorine Control Room and actuates an alann if the high or low pressure setpoints are exceeded.
The nitrogen buffer between the rupture disks on the F storage tanks is monitored by a pressure 2
indicator and a pressure blind switch that actuates an alann on high or low pressure. liigh pressure would indicate leakage through the inboard rupture disk. Low pressure would indicate leakage of the nitrogen buffer or the outboard rupture disk. If the pressure exceeds the setpoint, an alarm is actuated in the X-342A Fluorine Control Room.
Pressure blind switches are also located on the F and 11 headers that activate visual and audible 2
2 alanns in the X-342A Fluorine Control Room when Duorine or hydrogen header pressure exceeds the setpoint.
Leakage of F or oil through any diaphragm of the F compressors is detected and annunciated 2
2 by audible and visual alanns in the X-342A Fluorine Control Room.
Actuation or failure of any of the Duorine leak detectors in X-342A will result in an alarm locally and in the X-342A Control Room. In addition, manual gas release alanns are located throughout the X-342 Building. Activation of these alarms will sound the building evacuation siren. Actuation of a detector in X 342B results in audible alarms locally and in the Duorine system control room in X-342A, 3.7.5.6 Maintenance and Testing Requirements The following maintenance and testing activities are conducted on the Fluorine Generation System due to the hazard present in the system:
system tanks and piping are visually inspected annually, 3.7-8 l
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1 SAR-PORTS PROPOSED-GRADE 2 October 28,1998 i
RAC 98X-XXXX l
1 ultrasonic thickness tests are performed on the F storage tanks every three years, e
2 an internal inspections of the walls and welds of the storage tanks and the surge tank are e
conducted every 10 years, and ultrasonic thickness tests are performed on the cooling / heating tubes in the fluorine e
generators when they are disassembled for maintenance.
3.7.5.7 Administrative Controls i
Administrative controls have been implemented to minimize the potential for a leak of11F or F2 from the Fluorine Generation System and to minimize the health effects to personnel in the event of such a leak, as discussed in the Plant Safety Operational Analysis.
DOT-approved valve covers are in place on the IIF cylinders during storage and transport.
Only cylinder pigtails that have been inspected, approved, and tagged by a qualified inspector shall be used.
Pigtails shall be leak tested when connected to cylinders and prior to use.
Lines shall be purged and evacuated prior to opening the primary system.
1 3.7-9 1
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s' SAR-PGDP PROPOSED-GRADE 3 October 28,1998 RAC 98C-XXXX 3.4 UFs FEED, TRANSFER AND SAMPLING FACILITIES 3.4.2 Autoclaves and Autoclave Systems This section (to be provided later) contains brief descriptions of the C-333A, C-337A, and C360 autoclave facilities with references to sections 3.4.I, 3.4.3, and 3.4.4 that describe the overall facilities, the sampling systems, and the building structures and confinement systems in detail.
3.4.2.1 Autoclave High Pressure Isolation System TO BE PROVIDED MTER 3.4.2.2 Autoclave Primary Containment System TO BE PROVIDED MTER 3.4.2.3 Autoclave WaterInventory Control System TO BE PROVIDED UTER 3.4.2.4 Autoclave Opening Prevention System TO BE PROVIDED UTER 3.4.2.5 Autoclave Steam Conductivity Isolation System TO BE PROVIDED UTER 3.4.2.6 High Cylinder Pressure System TO BE PROVIDED UTER 3.4.2.7 Low Cylinder Pressure System TO BEPROVIDED UTER 3.4.2.8 Autoclave Steam Pressure Control System TO BE PROVIDED U TER 3.4.2.9 Autoclave Pressure Relief System 3.4-1
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l SAR-PGDP PROPOSED-GRADE 3 October 28,1998 RAC 98C-XXXX l
Each autoclave is equipped with an Autoclave Pressure Relief system to prevent the internal pressure from exceeding 110% of the maximum allowable working pressure (MAWP) as determined by Section VIII of the ASME Pressure Vessel Code. This system consists of a pressure relief valve and a rupture disc, each rated at the MAWP for the autoclave on which they are installed. The rupture disc l
prevents constant exposure of the pressure relief valve to steam that is present during normal operation.
l Such constant exposure could cause undesirable corrosion and scaling of the valve, which, in turn, could cause the valve to weep or otherwise fail to perform its design function.
Pressure above the rating of the pressure relief valve would be vented to the atmosphere through a vent line above the roof. The relief valve closes when the autoclave pressure drops below the MAWP to limit the amount of any release. Reaction products would not be released through the pressure relief valve at pressures below the set point of the valve. This relief system could only be caused to function if there were an excessive amount of water (see Section 3.4.2.3) in the autoclave at the time of a UF.
release within the autoclave.
The pressure rupture dise performs a passive safety function as a component of the autoclave primary containment system (Section 3.4.2.2).
No support systems are required for this pressure relief system.
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3.4-2
_..._.__..._-_..-_...-...._.m L
SAR-PGDP 1 PROPOSED-GRADE 4
. October 28,1998 RAC 98C-XXXX
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3.9.1 ' C-100 Administration Building '
r The C-100 administration building provides the offices for plant administration, support personnel, and the Nuclear Regulatory Commission. The building location is shown on Figure 2.1-4.
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3.9-1
GDP 98-0247 3 Pages Updated Chapter 3 Proposed Table of Contents 1
_m_.___. _ _.. _ _ ____ _
1 i
l PROPOSED October 28,1998 CHAPTER 3 TABLE OF CONTENTS 3.0 FACILITY AND PROCESS DESCRHTION
3.1 INTRODUCTION
]
l_
3.2 FACILITY AND PROCESS DESCRIPTION h
l 3.3 ENRICHMENT FACILITIES l
1 3.3.1 Enrichment Cascade 3.3.2 Purge Cascade 3.3.3' Freezer / Sublimer 3.3.4 Cold Recovery
[
3.3.5 Wet Air / Seal Exhaust 3.3 6' Datum System
?
3.3.7 Freon Degrader 3.3.8 Cell Treatment i
3.3.9 Building Structures and Confinement 3.4
.UF, FEED, TRANSFER AND SAMPLING FACILITIES 3.4.1 Feed and Transfer Facility Systems l
3.4.2 Autoclaves and Autoclave Systems j
3.4.3 Sampling System 3.5 UF, WITHDRAWAL FACILITIES l
3.5.1 Withdrawal Systems 3.5.2 Product Withdrawal 3.5.3 Tails Withdrawal 3.6 UF, CYLINDERS, CYLINDER HANDLING AND STORAGE 3.6.1 UF. Cylinders 3.6.2 UF Cylinder Handling and Weighing 3.6.3 UF, Cylinder Storage 3.6.4 UF. Pigtails 3.7 GENERAL FACILITY SAFETY SUPPORT SYSTEMS, UTILITY SYSTEMS AND COMMUNICATION SYSTEMS 3.7.1 Criticality. Accident Alarm System 3.7.2 Fire Protection Systems
'3.7.3 UF, Release Detection System 3.7.4 Communications Systems 3.*/.4.1 Nonnal Communication System 3.7.4.2 Plant /Public Warning System l
3.7.4.3 Emergency Lighting System i
, - + -
i i
PROPOSED October 28.1998 CHAPTER 3 TABLE OF CONTENTS 3.7.5 Non-Radiological Chemical Systems 3.7.6 AC Electrical Systems 3.7.7 DC Electrical Systems 3.7.8 Utility Systems 3.7.8.1 Plant Water System 3.7.8.2 Plant Nitrogen System 3.7.8.3 Heating and Ventilation Systems l
3.7.8.4 Plant Steam and Condensate Systems i
3.7.8.5 Plant Air System 3.8 DECONTAMINATION, WASTE STORAGE AND MISCELLANEOUS SUPPORT FACILITIES 3.8.1 Decontamination Facility and Systems i
3.8.2 Miscellaneous Waste Storage and Handling Facilities 3.8.3 Miscellaneous Support Facilities 1
3.8.4 Radiation Calibration Facility 3.9 GENERAL SUPPORT FACILITIES AND SYSTEMS 3.10 SAFETY SYSTEM CLASSIFICATION 1
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l GDP 98-0247 Page1of1 l
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l Com.mitments Contained in this Submittal l
l 1.
The impact, if any, on the October 31,1999, completion date for submittal of the Chapter 3 update due to intermediate milestone date changes is currently being assessed. USEC will notify the NRC should the results of this assessment indicate a need to revise the October 31, 1999, submittal date for the Chapter 3 Update.
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