ML20148A225
| ML20148A225 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 03/15/1988 |
| From: | POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | |
| Shared Package | |
| ML20148A224 | List: |
| References | |
| PROC-880315, NUDOCS 8803170187 | |
| Download: ML20148A225 (23) | |
Text
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ATTACHMENT TO JPN HYDROGEN WATER CHEMISTRY SYSTEM FOR JAMES. A FITZPATRICK NUCLEAR POWER PLANT NEW YORK POWER AUTHORITY JAMES A FITZPATRICK NUCLEAR POWER PLANT DOCKET NO. 50-333 DPR - 59 8803170187 880315 PDR ADOCK 05000333 P DCD
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CONTENTS '
1 I. SYSTEM MODIFICATION DESCRIPTION A. PURPOSE B. DESIGN CONSIDERATIONS
- 1. Hydrogsn Storage
- 2. Hydrogen Injection
- 3. Oxygra Storage
- 4. Oxygen Injection
- 5. Instrumentation and Control
- 6. Mitigation of Line Breaks and Leak Detection
- 7. Crack Arrest Verification System C. OTHER CONSIDERATIONS i 1. Radiological Protection Program
- 2. LWR Water Chemistry Guidelines J
- 3. Effects of Hydrogen Concentratica I
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- 4. Environmental Qualification
- 5. Fuel Surveillance
- 6. Operation, Maintenance, and Training i II. COMPLIANCE i
III. REFERENCES l
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I. SYSTEM MODIFICATION DESCRIPTION A. EURPOSE The purpose of the hydrogen water chemistry program is to prevent Intergranular Stress Corrosion Cracking (IGSCC) and inhibit the growth of any existing stress corrosion cracks in austenitic stainless steels by altering the reactor water chemistry. The recirculation and ECCS piping systems contain austenitic stainless steels. Tests previously performed have shown that controlling the conductivity, reducing the dissolved oxygen concentration, and lowering the electrochemical potential in the reactor recirculation water will mitigate stress corrosion cracking.
The hydrogen water chemistry program consists of three major parts:
hydrogen / oxygen addition sample panel replacement crack arrest verification The hydrogen / oxygen addition system consists of two major subsystems.
One subsystem injects hydrogen gas into the feedwater system in order to reduce dissolved oxygen concentration in the reactor recirculation water.
The other subsystem injects oxygen gas into the offgas recombiner system to recombine with the hydrogen rich non-condensible gases that are carried in the main steam to the condenser. This is done to insure that sufficient oxygen is present to insure complete and safe recombination. The oxygen subsystem also supplies a small fraction of oxygen to the condencate system to maintain the feedwater oxygen concentration between 20 and 50 ppb in accordance with the BWR Water Chemistry Guidelines.
The sample panel replacement modification is twofold in purpose. Both the Reactor Building Sample Panel SP-7 and the Turbine Building Sample Panel, SP-8, will provide state-of-the-art continuous monitoring as part of the water chemistry data management system at JAF. The function of the panels is to continuously and automatically obtain various 6446) 1
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. A. PURPOSE (Cont'd) process water samples from throughout the BNR cycle and analyse them for specific chemistry components. In addition, o the Reactor Building Sample Panel SP-7 provides reactor water dissolved oxygen input to the hydrogen injection system and reactor water dissolved oxygen, hydrogen, pH and conductivity data to the Crack Arrest Verification System.
NOTE: These inputs will be provided temporarily by the portable panel until Panel SP-7 is installed.
! The purpose of the Crack Arrest Verification (CAV) system is to provide information on the effectiveness of the hydrogen water chemistry program and verify that the non-IGSCC regime has been obtained. The CAV system accomplishes this by
- providing real time crack growth measurements for three j different materials found in the recirculation system. These
! materials are sensitized Type-304 stainless steel, Inconel Alloy 600, and Inconel Alloy 182. IGSCC pre-cracked test specimens that were fabricated from these materials are mounted within a crack growth autoclave. A penetration through the autoclave enables the application of a constant load that creates a stress environment equivalent to that in
, the recirculation system. Reactor (recirculation pipe)
] sample fluid will normally flow into and out of the crack j growth autoclave which contains the material specimens. The specimens are therefore subjected to the same chemical, j temperature, and pressure variables as the reactor recirculation system. The CAV system also monitors the i electrochemical potential of the reactor recirculation water.
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- B. DESIGN l
1.
Hydrogen Storage l Bulk or gaseous hydrogen, 99.99% pure, is supplied from
! permanently installed high pressure vessels. Location of the
- vessels is shown on the attached Drawing No. 11825-rY-2C-4A.
Each vessel has a volume of 9,333 standard cubic feet of i hydrogen. There are 30 vessels--15 to be dedicated for j operation, with 15 for backup--for a total storage volume of l
279,990 standard cubic feet. These vessels are constructed i as seamless vessels with swagged ends and designed per ASME
! Section VIII, Division 1 for up to a maximum allowable j working pressure of 2450 PSIG. They are installed to I
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B. DESIGN (Cont'd) withstand seismic and tornado events in accordance with FSAR requirements. The vessels are recharged approximately every two weeks by transportable tube trailers designed and constructed per Department of Transportation (DOT)
Standards. In order to unload the hydrogen gas from the tube trailers, a discharge stanchion is provided. The stanchion consists of a flexible pigtail, shut-off valve, Check valve, bleed Valve and necessary piping. Filling apparatus is separated from other equipment for safety and convenience and supported in a manner to minimize damage f rom a collision.
A tube trailer grounding assembly for the discharge stanchion is provided. The function of this assembly is to ground the tube trailer before the discharge of hydrogen begins.
A pressure control station is provided to maintain required hydrogen pressures entering the plant. The pressure control station manifold is designed specifically for this installation. The automatic reducing manifold has two full-flow pressure reducing regulators in parallel. Pressure gauges are provided upstream and downstream of the regulator. Sufficient hand valves are provided to insure complete operational flexibility.
An excess flow check valve is installed in the manifold immediately downstream of the regulators to preclude hydrogen leakage in the event of a line break. The stop-flow setpoint of 100 scfm has been set above the maximum plant flow requirement of 70 sefm during filling of the generator.
The bulk hydrogen supply system including the gas discharge stanchion and interconnecting piping has been designed to meet or exceed the requirements of the Guidelines for Permanent BWR Hydrogen Water Chemistry Installations (hereafter referred to as the BWR Guidelines) (ref. 1) and USAS Bal.1.0-1967. The site selected for the hydrogen supply has been reviewed to insure that the siting meets the requirements for protection of personnel and equipment as addressed in NFPA 50A. Gaseous Hydrogen Systems, and other design considerations addressed in the BWR Guidelines relative to safety related air intakes, fencing, and routing of hydrogen delivery (See Figures 1 & 2). Nearby existing lighting will facilitate night surveillance.
Hydrogen will be delivered to the site in transportable tube trailers built to DOT standards. The volume of a tube 6446j 3
I B. DESIGN (Cont'd) trailer is approximately 110,000 cubic feet. The total amount of time a truck could be closer to safety-related i structures than the storage area is, as it passes from the security gate north along the road at the west edge of the protected area to the hydrogen storage area, is estimated at less than two hours per year. While onsite, the truck will operate in accordance with 10 CFR 73.55. Truck barriers are installed around the storage area. The existing hydrogen tube storage area will be abandoned and demolished. Hydrogen to the generator will be supplied by the new bulk storage supply shown in Drawing No. 11825-rY-2C-4A.
- 2. Hydrogen Injection Hydrogen is injected into the condensate system as shown in the attached Drawing No. 11825-FM-89B at the suction of the Condensate Booster Pumps located at elevation 252'-0" in the j Turbine Building. A line from the bulk supply is initially routed to a common header utilizing part of the existing hydrogen line for generator cooling. From this header, the flow is directed to the four train hydrogen injection rack 89RA-1 located at elevation 272'-0" of the Turbine Building.
Hydrogen flow is controlled to each condensate booster pump (33P-9A,B,C) through independent flow control valves FCV100A, FCV100B, FCV100C. Pressure transmitter PT150 provides
- pressure indication and a trip interlock at the hydrogen control panel 89 HAP-1. Each line at the rack contains a i solenoid-operated automatic isolation valve interlocked to j the corresponding pump, so that hydrogen is not injected into
- a pump that is not running. Hydregen is injected at a flow rate of 10.8 scfm at 100% power and is normally controlled automatically as a function of feedwater flow and trimmed by recirculation loop dissolved oxygen from the Control panel 89EAP-1 located in the radwaste building at elevation 272'-0".
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The fourth redundant train utilizes control valve FCV100D to
, ,11ow flow to any pump should any train be out-of-service.
- Manual isolation valves of diaphragm type are provided in l each pump injection line to accommodate pump out-of-service
! conditions.
- 3. Qxygen Storage Liquid oxygen, 99.0% pure, is supplied from a vacuum jacketed
) vessel. The inner vessel has a capacity of 3,000 gallons and t
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B. RESIGN (Cont'd) is designed for a pressure of 250 psig and temperature range from -320*F to +100'F over ambient. The inner vessel is designed, fabricated, and tested in accordance with ASME Section VIII, Division 1. Oxygen is taken from the vessel and vaporized through ambient air vaporisers. The oxygen gas is routed through a pressure control station to maintain oxygen gas pressures within the desired range. The tank, controls, and interconnecting piping are provided in accordance with the requirements of BWR Guidelines and USAS B31.1.0-1967.
The site selected for the oxygen supply as shown in the 4
attached Drawing No. 11825-FY-2C-4A has been reviewed to insure that it meets the requirements for protection of personnel and equipment as addressed in NFPA 50, Bulk Oxygen l Systems, and other design considerations as addressed in the BWR Guidelines including location of the system relative to safety related air intakes, fencing and routing of oxygen delivery (see Figure 3). Nearby existing lighting will facilitate night surveillance. The distance between the hydrogen and oxygen facilities is 100 feet. All portions of the oxygen supply system will be cleaned in accordance with CGA G-4.1, Cleaning Equipment for Oxygen Service.
- 4. Qxygen Iniection Oxygen is injected into the offgas system upstream of the recombiner at elevations 272'-0". A copper tubing line with silver soldered joints is routed from the oxygen system pressure control cabinet at the vessel through the turbine building to the offgas oxygen injection rack 89HA-3 at elevation 252'-0" of the Turbine Building to the steam dilution line at the Offgas Recombiner System, elevation 272'-0". The injection rack is provided with two parallel flow control valves FCV300A and FCV300B for system
! reliability and maintenance. Oxygen supply pressure i transmitter PT/300 is also provided on the eack to provide pressure indication and a trip interlock at the hydrogen control panel 89 HAP-1. Oxygen flow rate is controlled to provide excess oxygen downstream of the recombiners. Design of system controls insures that oxygen injection continues i after hydrogen flow stops. This insures that excess oxygen i remains present after hydrogen injection ceases so that all free hydrogen recombines.
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i B. DESIGN (Cont'd)
Oxygen is also injected into the condensate system as shown in the attached Drawing No. 11825-FM-89C at the condensate 4
pump suction header. This is accomplished by means of the oxygen flow control valve FCV200 located outside the condensate pumps room on elevation 252'-0". Pressure transmitter PT/200 provides pressure indication and a trip interlock at the hydtogen control panel 89 HAP-1. Oxygen injection in the condensate system is necessary as a result
, of reduced oxygen levels found in the feedwater during the GE l
mini-test. The addition of approximately 0.05 scfm oxygen to the feedwater maintains the oxygen concentration at a level between 20 to 50 ppb in accordance with the BWR Water i Chemistry Guidelines. (Actual oxygen injection values will be
- determined during pre-operational testing).
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- two oxygen monitoring subsystems, feedwater flow i instrumentation, and the hydrogen addition system control
] panel 89 HAP-1 complete the hydrogen / oxygen addition system.
q Three reactor recirculation water dissolved oxygen analysers 0 2 1T/1A, 0 2 IT/1B and 0 2 IT/1C are located in the Reactor 1 Building Sample Panel SP-7 to provide trim and recording I
functions at control panel 89 HAP-1. Analysers 1A and 1B provide selector switch (Train A/ Train B) signals (0-20 ppb) for hydrogen injection trim control and analyser 1C provides l autoranging (0-20 ppb - 200 ppb) signals to recorder 0 2AR/1.
Offgas monitoring is provided to measure the percentage of oxygen exiting the offgas recombiner dryer. A selector 4
switch along with the two offgas rusidual oxygen analysers l are located in the offgas hydrogen cabinet 01-1070GA-HAC
! located in the East Electric Bay. The analysers monitor the
- existing sample stream in the cabinet. The analysers provide 1 control and recording functions at control panel 89 HAP-1.
The analysers will trip the hydrogen injection system from
- the control panel 89 HAP-1 on residual oxygen levels less than j 5 percent.
1 Feedwater flow input to 89 HAP-1 is provided from the existing
. feedwater flow control system located in Panel 09-18 in the j Control Room. A curreut-to-current isolator 89I/I-01 is provided to prevent hydrogen system faults from affecting feedwater control.
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B. DESIGN (Cont'd)
The hydrogen addition control panel 89 HAP-1 is located in the ,
Radwaste Building at elevation 272'-0" next to the offgas Centrol '
Panel. The fully automatic operation of hydrogen and oxygen injection is controlled from this panel. Since the panel is esmeto from the main control room, a manual trip pushbutton and system "on" indicating light are provided on Panel 09-06 in the main control room. In addition, two alarms "H2 Syr. tem Shutdown",
"H2 System Trouble" are provided to alert the (perator in the control room.
The following instruments and controls are located on the hydrogen addition control panel 89 HAP-1:
Instrument Manufacturer & Model (1) Annunciator Panalarm Series 90 *
(1) H2 Monitor General Monitor Model 610 (1) Elapsed Ti.te Meter Eagle Signal Controls Model DX100 (2) Indicators Moore Products Model 372 (2) Recorders Moore Product Model 362 (6) Controllers Moore Products Model 352 (4) Pushbuttons General Electric Series CR2940 (2) Selector Switches General Electric Series CR2940 (4) Indicating Lights General Electric Series CR2940 Hydrogen flow demand is a multi-step linearized function of feedwater flow with reactor water dissolved oxygen used as a trim function. Since the total flow is being injected into three pumps, three flow indicating controllers, FIC-01, FIC-02, and FIC-01 provide one third of the required flow to each pump. the fourth controller, FIC-04, serves the fourth spare train. FIC-01 serves r as a master con
- roller and allows the operator to select either external or internal modes of operation. On external, a setpoint can be selected for trim based on dissolved oxygen concentration.
On internal, the feed forward signal is based on feedwater flow.
Total hydrogen flow provided by the sum of the four train mass flow meters FE/100A, FE/100B, FE/100C and FE/100D provides the feed forward input signal to the offgas oxygen flow indicating controller FIC-05 in the external mode. This signal can be trimmed by the of fgas excess oxygen measurement in the internal mode by selecting "I" on controller FIC-05.
The following control features are provided to insure safe and reliable operation of the systems 6446j 7
B. DESIGN ' Cont'd) o Trim of hydrogen flow control on reactor water dissolved oxygen is limited to 220%;
o Oxygen flow will hold at last valve position whenever hydrogen flow is decreasing greater than 1 scfm/ minutes o Oxygen flow is held at last valve position for 15 minutes following hydrogen injection system trips o Oxygen flow rate cannot decrease faster than 1 sefm/ minutes and o Trim of oxygen flow control on offgas residual oxygen is limited to 120%.
The following system trips will close the three injection solenoid valves SOV-100, SOV-103 and SOV-106 and the two oxygen injection solenoid valves SOV-200 and SOV-300s o Loss of control power at panel 89 HAP-1.
o Teodwater flow less than 20% rated flow (< 20% rated power) o RX SCRAM o Main control room or local manual (pushbutton) shutdown of hydrogen and oxygen injection o Low oxygen injection supply pressure at offgas system less than 150 psig or at condensate system less than 50 psig after 2-second time delay o Low residual oxygen in offgas less than 5 percent o Offgas or recombiner trip o Low hydrogen injection supply pressure lean than 300 psig after 2-second time delay o High area hydrogen concentration will alarm at 1% and trip the main hydrogen trip valve at 2%. Subsequent low hydrogen injection supply pressure will close the three injection solenoid valves.
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B. RESIGN (Cont'd) o High hydrogen flow will close excess flow check valves.
Resulting hydrogen injection supply pressure less than 300 psig after 2-second time delay will close the three injection solenoid valves.
Presently, the high residual oxygen trip and alarm as indicated in Tablas 2-1 and 2-2 of the GWR Guidelines are not included in the design of the Oxygen Injection System. This trip and alarm were recommended to lusure that oxygen concentrations do not increase to an unacceptable level for possible combustion in the offgas adsorber charcoals. The system, hcwever, includes fail close flow control valves in series with fall close isolation solenoid valves. A failure in either the air supply to the flow control valves or electrical supply to the solenoid valves will close the respective valves and trip the Hydrogen Addition System on low oxygen eupply to the offgas system.
The Oxygen Injection System also includes mass flowmeters in series with the flow control valves and isolation solenoid valvos. These flowmeters and associated flow indicating coutrciler control P.he injection rate to the offgas system at one nalf the hydrogen injection rate. Normally the system will be injecting 5.4 scfm oxygen at 100% power. In the unlikely event of a failure in the flowmeter and flow indicating controller, the demand for oxygen may exceed the amount required for recombination with hydrogen and the flow control valve may go to the full open position. In this event, the oxygen injection rate may reach 10 scfm, the deelgn value t'or the oxygen injection system. Assuming that the hydrogen injection system and offgas recombiner system are operating and the condenser air in-leakage to the offgas
! system is 20 scfm, the maximum oxygen concentration in the offgas passed through the charcoal vessels is calculated to bo 3b%. At Tit: Patrick, the air in-leakage from the condenser is normally 30 to 40 scfm at all power levels.
This results in a maximum oxygen concentration to the charcoal vessels of 31% to 29% (oxygen concentration decreases with increasing condenser air in-leakage).
! Consequently, oxygen concentrations will not exceed 40%, the level above which is considered unacceptable for possible combustion in the offgas adsorber charcoals.
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B. DESIGN (Cont'd)
In the event that hydrogen injection stops for any of the trips indicated above, the Oxygen Injection System will also stop 15 minutes after hydrogen injection to ensure full recombination. If the offgas recombiner trips, hydrogen injection will also trip and 15 minutes later oxygen injection will trip. In this event, the offgas recombiner and adsorber charcoals will be bypassed. The hydrogen rich offgas will be passed directly to the offgas holdup pipe - a pipe designed to withstand hydrogen explosions - and thereafter, to the offgas stack.
For conservatism in the design, this additional high residual oxygen trip and alarm will be added during an outage of sufficient duration following the 1988 refueling outage.
This will ensure that even in the unlikely event of multiple failures in the oxygen and hydrogen injection control systems, the Hydrogen Addition System will alarm on high residual oxygen concentration in the offgas greater than 30%
and will trip on high residual oxygen concentration greater than 40%.
Procedural control will be used on an interim basis to ensure that residual oxygen concentration is kept below 40%. This control will consist of mor.itoring condenser air in-leakage so that it remains in excess of 20 scfm and observing local oxygen concentration readings at the offgas oxygen analyzers and hydrogen addition control panel on a daily basis during ro'atine surveillance. Procedures will require that if oxygen l concentration reaches 40%, the Hydrogen Addition System will be manually tripped. Procedures will also require the operator to verify that the Oxygen Injection System has tripped following a hydrogen injection trip.
All other instrumentation and control as indicated in the guidelines have been included in the design of the system.
Trip of any condensate booster pump will trip its associated solenoid valve, but not the system.
l The instrumentation provides indication and/or recording of l parameters necessary to monitor and control the system and its equipment. The instrumentation also indicates and/or alarms abnormal or undesirable conditions.
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B.- DESIGN (Cont'd)
- 6. Mitication of Line Breaks and Leak Detection In addition to the above electrical control system trips, the hydrogen piping system is provided with excess flow check valves which will isolate the injection system from the supply system on high hydrogen flow.
Hydrogen leak detection inputs to the panel 89 HAP-1 consist of area hydrogen detectors H2E/lA, H2E/lB, H2E/IC and H2E/lD.
Detector lA is located at the isolation trip valve SOV-50.
Detectors 1E and 1C are located in the Turbine Building on elevation 252'-O", near the Condensate Booster Pump injection points. The fourth detector, ID, is located in the hydrogen injection rack 89HA-1 which is covered with a shroud. All detectors are located in the ceiling, except for detector ID. All four detectors are wired to the monitor located in panel 89 HAP-1.
- 7. Crack Arrest Verification (CAV) System The CAV system supplied by General Electric provides real time measurements of the crack growth behavior in tent specimens of those materials of interest for the plant primary feedwater recirculation system Sensitized type - 304 stainless steel, Inconel Alloy 600, and Inconel Alloy 182. The CAV system also monitors electrochemical potentials (ECP) and receives chemistry signals from a chemistry panel.
The CAV system consists of three distinct packages--the load frame, the chemistry panel, and the data acquisition console.
These are all located in the Reactor Building on elevation 300'
-00" and are connected by approximately 60 feet of nuclear grade, pre-calibrated, fire-resistant cables, also supplied by General Electric.
The load frame, which is approximately 80" high, 40" wide, by 20" deep, consists of a flow manifold, two electrochemical potential (ECP) autoclaves, and a crack growth autoclave. The load frame flow manifold is supplied by the reactor water recirculation system. It measure the flow rate and directs the high pressure, I high temperature water either to or electrochemical monitoring
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B. DESIGN (Cont'd) autoclave or to the crack growth monitor autoclave. An analog voltage signal representing this flow is also provided to the data acquisition module. The water is returned to the reactor water clean up system.
The chemistry panel consists of conductivity pH, hydrogen and oxygen cells, gas calibrator, isobath, and other coolers.
Initially this function will be performed by a portable cart secured to the floor. A permanent panel will be installed later. A separate flow from the recirculation sample line supplies water to the chemistry panel.
The data acquisition console consists of all the instrumentation required to interface with both the load frame and the chemistry panel (eg. computer, data acquisition units, multi-meter power supply, etc.).
Together these three distinct packages form three separate monitors--the Crack growth monitor, the ECP monitor, and the chemistry monitor.
The crack growth monitor consists of the crack growth autoclave, the load frame, and the interface with the data acquisition system. The crack growth autoclave has a design pressure of 1500 psig and a design temperature of 650'F. Test specimens with pre-existing IGSCC cracks are mounted inside the autoclave. Penetrations through the autoclave head allow for the application of a load and also provide a path to transmit signals from the crack tip to the data acquisition console. The load applied is constant and creates a stress environment equal to that in the recirculation system. The crack growth monitor is capable of producing a crack length reading in each specimen which is stable within + 0.0005 inches over a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period in both air and demineralized water environments under no-load conditions, which are known not to produce crack growth.
The ECP monitor consists of electrodes, two 1-liter autoclaves, and the interface with the data acquisition system. The electrodes are housed in the autoclave and transmit ECP signals to the data acquisition console. The autoclave has a design pressure aad temperature of 5800 psig and 650'F respectively.
The ECP monitor is used to evaluate the electrochemical effect of reactor water on crack growth rates. The temperature of the water exiting the ECP autoclave is also monitored.
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B. DESIGN (Cont'd)
The chemistry module consists of accessing chemistry signals from the portable chemistry cart (or SP-7). Dissolved oxygen, dissolved hydrogen, pH, and conductivity are transmitted to the data acquisition console.
The data acquisition system integrates the data from these three monitors and creates a common CAV data base, which is stored on a 10 megabyte hard disc. The CAV software allows the user to access the CAV data and better understand what factors contribute to crack growth in the recirculation system.
C. OTHER CONSIDERATIONS
- 1. Radioloalcal Protection Procram The existing Radiological Protection and ALARA programs at JAF are adequate to ensure that radiological exposures to plant personnel and to the general public are consistent with ALARA requirements. The hydrogen water chemistry mini-test demonstrated that these existing programs remain adequate during hydrogen water chemistry operating conditions.
During this mini-test, radiation measurements were taken throughout the plant and surrounding environs out to the site boundary. Pressurized ion chambers and portable germanium detectors were used to extensively monitor radiation buildup with increasing hydrogen injection. Measured exposure rates i
were shown to be proportional to main steam line radiation l monitor readings and hence can be predicted by these monitor readings.
The results of the mini-test indicated in-plant nuclear steam l
i system radiation dose rates would increase by approximately twenty-five percent at the recommended hydrogen injection rate needed at JAF. Radiation dose rates increased by a factor of six at the maximum hydrogen injection rate used during the l mini-test. The adequacy of existing programs would be l reassessed if the hydrogen injection rate is to be increased .
significantly from the current recommended value.
l At the recommended hydrogen injection rate, the radiological program in place at JAF is adequate to control personnel radiation exposures as low as reasonable achievable. JAP will continue to operate within Technical Specification and 10 CFR 20 limits during hydrogen water chemistry operations.
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C. OTHER CONSIDERATIONS (Cont'd)
- 2. BNR Normal / Hydrogen Water Chemistry Guidelines The Authority recognizes that for Hydrogen Water Chemistry to be effective in mitigating Intergranular Stress Corrosion Cracking, two conditions are required to be met - reduction of the corrosion potential in the reactor coolant and maintenance of good reactor water chemistry.
In order to meet the first condition, the Authority is implementing a Hydrogen Addition System which, in conjunction with a Crack Arrest Verification System, will lower and monitor the electrochemical potential of the reactor coolant to less than -230 mV (standard hydrogen electrode) in accordance with the BWR Hydrogen Water Chemistry Guidelines (Reference 3).
In order to meet the second condition of maintaining good reactor water chemistry, the Authority is preparing a plant chemistry manual. The "BWR Normal Water Chemistry Guidelines" (Reference 2), and "BWR Hydrogen Water Chemistry Guidelines" (Reference 3), developed by the BWR Owners Group, are under review by the Authority, and applicable sections will be used as a basis for developing this chemistry manual. The manual will incorporate the applicable limits, corrective actions, process monitoring, calibration, and sampling frequencies. Any plant procedures requiring changes to incorporate the plant- specific water chemistry control program stated in the manual will be revised. The manual will also include a section on "Responsbilities".
- 3. Effects of Hydrogen Concentration As HWC reduces dissolved oxygen concentrations, total non-condensible flows with HWC will be less than before HWC, because of the sharp reduction in radiolytic oxygen reaching the offgas system. Even though the fraction of total ron-condensibles contributed by hydrogen will increase with HWC, the maximum expected flow of hydrogen in the offgas is well below the flow for which the offgas system is conservatively l designed. Therefore, there will be no impact on overall l
operation of the offgas system due to HWC.
I Oxygen is being injected directly into the steam dilution line, which is a well-diluted portion of the offgas system, as l required by the BWR Guidelines. This ensures that the ch'nge in
[ composition of offgas flows due to HNC will not significantly increase the probability of combustion.
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C. OTHER CONSIDERATIONS (Cont'd)
- he non-condensible gas composition in the main condenser will change to a hydrogen-rich mixture. Because radiolytic oxygen will be reduced, there will also be a net decrease in the total non-condensible gas flow. Neither condition creates safety concerns for any equipment.
HWC may slightly increase the possibility of introducing hydrogen to the torus via SRV blowdown, compared with non-RWC conditions. However, oxygen blowdown under HWC would be reduced. This fact, plus the inerted containment, eliminates the potential for combustible mixtures in the containment.
The floor sumps and equipment drain sumps in the reactor building, drywell, radwaste, turbine building, and pipe tunnel have been reviewed with respect to HWC. No combustibility concerns exist at any sumps.
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- 4. Environmental Oualification Hydrogen water chemistry has no effect on post-accident radiation doses. Environmental qualification data have been reviewed for components normally exposed to main steam, which will contain a higher concentration of N-16 due to HWC. Such components include the main steam line radiation monitors and certain other instruments.
Because of the relatively small (20% to 25%) increase in activity documented during the mini-test, operation of the Hydrogen Addition System will have no effect on the qualification of any of these pieces of equipment. All of the instruments are qualified to a minimum of three times the expected total integrated dose. Dose rates inside the drywell will actually decrease, due to the increased carry over of N-16 in the main steam.
- 5. Fuel Surveillance The Authority has followed the EPRI Dresden program of fuel surveillance under RWC, and has concluded that this experience j is applicable to FitzPatrick. Given the good results at Dresden, the Authority has no immediate plan for a fuel surveillance program at FitzPatrick to examine the effects of HWC. This position is compatible with the recommendations and guidance given by FitzPatrick's fuel vendor. Operation of HWC system will not affect fuel warranty as confirmed by the fuel vendor.
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C. OTHER CONSIDERATIONS (Cont'd)
- 6. Ooeration, Maintenance, and Training Operation of the HWC system will be in accordance with the BWR Owners Group guidelines. Plant Operating Procedures are being developed and training will be provided prior to system start-up.
Maintenance will be performed according to existing plant procedures. Any potential impact on erosion / corrosion of carbon steel piping (RWCU, RHR) affected by implementation of HNC will be monitored during inspection performed for erosion.
II. COMPLIANCE The HWC system is designed and installed in accordance with all applicable codes, standards, and regulatory requirements. It complies with the BWR Guidelines, eith the exception of the high residual oxygen trip and alarm as discuss;d in Section I.B.S. Location of the hydrogen and oxygen storage equipment is in accordance with requirements in the BWR Guidelines, as shown in Figures 1, 2, and 3. Design, construction, and installation of the gas storage equipment also complies with the BWR Guidelines. All piping is pneumatically leak tested using soap bubble solution in accordance with FitzPatrick plant procedures.
Instrumentation and control features of the system are in compliance with the BWR Guidelines, except as noted above. Design and installation have been in accordance with existing applicable portions of the JAF and existing plant design procedures. Consideration of interactions between the NWC system and safety-related structures, systems, and components has been adequately addressed in the design of the system.
The HWC system will be operated in a manner that does not require modification to the set points of the Main Steam Line Radiation Monitors. Therefore, no Technical Specification changes are required to permit system operation. No margin of safety defined in the Technical Specifications is reduced by operation of the RWC system.
The interaction of the RWC system with systems and postulated accidents previously analyzed in the JAF FSAR has been considered. No accidents previously analyzed are affected by operation of the HWC system. The probabilities or consequences of such postulated accidents are not increased by operation of the HWC system.
By complying with the BWR Guidelines in the design, installation, and operation of the RWC system, as described above, the New York Power Authority assures that failure of the HWC system or its components will not cause any accidents or malfunctions of equipment important to 6446j 16
i safett which have not been previously analyzed in the Final Safety Anal'fsis Report; nor will their probability be significantly inczeased. The siting of hydrogen and oxygen storage tanks is such that their failure will have no adverse effect on safety-related st.ructures and there will be no reduction in the margin of safety by the operation of the NWC system.
Therefore, this report presents justification for the conclusion that design, installation, and operation of the HWC system is in accordance with 10 CFR 50.59.
III. REFERENCES
- 1. Guidelines for Permanent BWR Hydrogen Water Chemistry Installations -- 1987 Revision, EPRI NP-5283-SR-A, September 1987.
6446) 17
250 - ACTUAL DISTANCE
^-
ll 160 m 194nch reinforced concrete 140 - (a) P. m 1.5 psp. t 0.12 kal 200%
$)P.m3.0pel; a 0.30 kol
}
120 -_ ____________.
l Reinforced wat 100 a 8 inches thick
\
3 80 ~
, D I
40 - 9)
.0 _
i ACTUAL SIZE I I I I ll I -
, 10 12 id 4 g B 0 2 Yessel Size (thousands of SCF per vesset)
Minimum required separation distaxes to safety related structures versus vessel size for gaseous hydrogen I
storage system.
l 3
FIGURE 1
400 ACTUAL DISTANCE (ro m AAG) 300 E
Minimum required separation 250 distance to air pathways trWo safety-related structures 200 I 'l 100 -
Minimum rea.utted io .st iy.r.iased s paration
.irniures n distance m 84n. thick reinforced watts I
i a j
f ACTUAL SIZE f I I I a 1* 1* 1"
, # 1 0 % #
l inside Diameter of Largest Pipe On.)
l Minimum required separation distance versus ID of pipe for l
refenses from 2450 psig gaseous hydrogen stocage systerns.
l FIGURE 2
.s 60 50 E'O Accept dte i.e. tion et a.<.ty.r.i.ied ur mi. .s so 5 ACTUAL HEIGHT 40
- . "-(; .
% 5
\
a s g, 0 -
un.eceptwe i. canon of g a R "
safety related air intakes
/
' I I I !
f I I I I 11 I 1200 0 " 200 000 000 1000 400 O
Dcaes from Uguld oxygen Storage Tank (fi)
AcceptaWe i. cations of safety related air intakes for6 various sizes of liquid oxygan storage tanks.
ACTUAL DISTANCE-(ro ens auns Ara inrane)
FIGURE 3 I
~~ - -~ _ - - - , . _ _ _ _ ___ ""MT
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