ML20205N415

Forwards Changes to Sys & Procedures as Described in FSAR, Per Requirements of 10CFR50.59,covering Qualified Transmitters for Containment Spray Flow & high-range Containment Area Monitor Upgrade

ML20205N415
Person / Time
Site:	Three Mile Island
Issue date:	04/17/1986
From:	Hukill H GENERAL PUBLIC UTILITIES CORP.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
5211-86-2055, NUDOCS 8605020127
Download: ML20205N415 (17)

Text

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GPU Nuclear Corporation Nuclear  :::,ome::rteo s

Middletown, Pennsylvania 17057-0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:

April 17,1986 5211-86-2055

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Dr. Thomas E. Murley Region I, Regional Administrator U.S. Nuclear Regulatory Commission 631 Park Averue King of Prussia, PA 19406

Dear Dr. Murley:

Three Mile Island Nuclear Station Unit 1 (TMI-1)

Operating License Ho. DPR-50 Docket No. 50-289 10 CFR 50.59 Report for 1985 In accordance with the requirements of 10 CFR 50.59, enclosed are two copies l of changes to TMI-l Systems and Procedures as described in the FSAR.

l Sincerely, I

l . D. H ll Director, TMI-1 HDH/SM0/spb cc: Director, Office of Inspection & Enforcement Document Control Desk (40 copies)

J . F. Stol z 0541 A l

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'O GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation ,

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Modification: B/A 412471 - Qualified Transmitters for Containment Spray Flow Description of Modification:

This modification consisted of replacing the Containment Spray Flow Transmitters with environmentally qualified transmitters. The modification was minor in nature and resulted in the same configuration for measuring flow as existed with the original transmitter.

Safety Evaluation Summary:

The replacement transmitters are fully compatible with those that were originally installed. Therefore, the functions and basic configurations remain the same. Thus, this modification does not reduce the margin of safety of the TMI-l plant as described in the FSAR.

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Modification - B/A 412483 BWST/SHST D/P Transmitter Mod Description of Modification:

This modification replaced LI-819 with a Rosemount D/P transmitter DPT-819.

The output of DPT 819 was connected to the computer using existing wires previously utilized for the sodium thiosulfate level. In addition, a new power supply for the Rosemount transmitter was added to the NNI cabinets. A local pressure gauge was added to the sodium thiosulfate tank for determining level if required in the future.

Safety Evaluation Summary:

The containment building spray system at TMI-1 takes a suction on both the Borated Water Storage Tank (BWST) and Sodium Hydroxide Storage Tank (SHST) during an accident. In order to ensure that pH and boron concentration values are within the proper range during spray injection, it is required that the two tanks drain down properly. Draw down analysis has shown that proper draindown under all single failures requires the tank levels to be precisely maintai ned. Technical Specification limiting condition for operating (LCO 3.3.1.3.b) requires that SHST be 8' + 6" lower than the BWST. The reactor shall not be made critical unless this LCO is satisfied and is to be shutdown to cold shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> if the LCO is not satisfied for a continuous period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Replacing LI-819 provides a D/P transmitter which is less susceptible to transient and reverse pressure breakdown. This mod provides computer pt.

readout as opposed to requiring an operator to go to the BWST tunnel to take a reading. Providing accurate control room readout of differential level and appropriate operating procedures to periodically check to see that LCO is met provide the lowest risk that TMI-1 will not inadvertently violate the LCO. It also provides the best assurance that violating the LCO will be detected promptly. Thus, this modification does not reduce the safety of the plant as described in the FSAR.

Modification: High Range Containment Area Monitor, EQ Upgrade Description of Modification:

This modification installed new environmentally qualified triaxial cables and connectors in an existing conduit between the RB penetrations and the High Range Containnent Radiation Detectors (RMG-22 & RMG-23). A qualified environmental seal between the connectors and the penetration was provided.

Safety Evaluation:

This modification enhances the safety of the plant by installing triaxial cables inside containnent which are qualified to 10 CFR 50.49 for the High Range Rad Monitors RMG-22 and RMG-23, and sealing off the detectors from the LOCA steam environnent thereby assuring their operation during and af ter accident conditions. There are no unreviewed safety questions as a result of this modification.

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- Modification: B/A 412468 - Qualified Decay Heat and HPI Flow Indication Description of Modification:

This modification consisted of replacing the Decay Heat Removal, the HPI and the RC Pump Seal Return Flow transmitters with environmentally qualified transmitters. The Makeup Tank Level transmitter was also replaced with an environmentally qualified transmitter. The modification was minor in nature and resulted in the same configuration for measuring flow and level es existed with the original transmitters.

This modification also included replacement of the Decay Heat Coolers Outlet temperature and the Incore Thermocouple Cold Junction Compensation Temperature RTDs with environmentally qualified RTDs. There was no other change to the system and, therefore, the temperature measurement configuration remained the sa me.

In addition to the above, the Makeup Pump Auxiliary lube oil pressure switches were replaced with environmentally qualified pressure switches. There was no other change to the system and, therefore, the system operates the same as with the original switches.

Safety Evaluation Summary:

The equipment that was replaced is fully compatible with those in the existing systems. Therefore, the functions and basic configurations remain as originally designed. Thus, this modification does not reduce the margin of safety of the TMI-1 plant as described in the FSAR.

Modification - Fire Detection System Modification in the Auxiliary Building (B/A 412388 Phase III)

Description of Modification:

Seventeen ionization (smoke) detectors were added in the Auxiliary Building to comply with the requirements of 10 CFR 50 Appendix R. The smoke detectors are monitored by the existing / iliary Building ionization detector control panel on the Auxiliary Building ? elevation (fire zone AB-FZ-6). This existing control panel provides a loco, alarm and relay contacts for remote alarms in the TMI-l Control Room. Ten of the ionization detectors are installed in the heat exchanger vault (fire zone AB-FZ-1) over cable trays containing circuits required for safe shutdown. Seven ionization detectors are installed in the north end of the Auxiliary Building elevation 281' (fire zone AB-FZ-5) in the area adjacent to fire zone AB-FZ-4 and in the corridor leading to the heat exchanger vault. The existing control panel is equipped with a four-hour self-contained emergency power supply.

Safety Evaluation Summary:

Installation of the seventeen ionization smoke detectors neets a commitment made to the NRC in GPUN Report "TMI-l Fire Hazards Analysis Report and Appendix R Section III G Safe Shutdown Evaluation." The ionization detectors installed are commercial grade equipnent. The engineering and installation was performed as Inportant to Safety (ITS). All equipment is seismically mounted so as not to create a missle hazard. The probability of occurrence, or the consequence of an accident or malfunction of equipment previously evaluated in the Safety Analysis Report has not been increased. It is, therefore, concluded that the subject modification does not involve an unreviewed safety operation ~ per the criteria of 10 CFR 50.59.

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Modification - 480V ESV Control Center Firewall (8/A 412387)

Description of Modification:

A one hour rated firewall was installed between switchgear 480 VAC ESV CC 1 A and 480 VAC CC 1B. This equipment is located at floor elevation 305' in the Auxiliary Building.

This firewall was installed in order to comply with NRC requirement 10 CFR 50, Appendix R, Sections III G, J, and O. It separates redundant Nuclear Safety Related motor control centers which are located in the same fire zone and which are needed to bring the plant to safe shutdown.

Safety Evaluation Summary:

The engineering and installation of this firewall were performed as Important to Safety. It is seismically qualified. The probability of occurrence, or the e cuences of an accident or malfunction of equipment previously eval- :n the Safety Analysis Report has not been increased. This mot on does not involve any unreviewed safety questions per the criteria of lb 50 "" .

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Modification - Removal of THI-l Fluid Block Tanks and Foundations Description of Modification:

The Fluid Block tanks, foundations and local piping and instrumentation have been renoved from the Intermediate Building. The piping and instrument lines were cut and capped with threaded caps. The electrical connections for the two Fluid Block tank main control room alarms were cut and labeled as spares and annunciator windows left blank. The control instrumentation for the tank and valves was also removed. The renoval of the Fluid Block tanks and foundations provided much needed extra space at the entrance to the Reactor Buil ding.

Safety Evaluation Summary:

Amendment No. 93 to the TMI-1 Technical Specifications removed all discussions of the Fluid Block System from the Technical Specifications. The system's original design basis had been to ensure that certain lines penetrating the containnent are pressurized with fluid to provide a seal against leakage of the containment atmosphere to the environment during any condition requiring containnent isolation. Since then, the penetration isolation valves served by the Fluid Block System have been tested to the requirements of 10 CFR 50 Appendix J. This means the Fluid Block System is no longer necessary for containment isolation. The removal of the tanks, foundations and accessories was performed to the required TMI procedures.

As a result, the probability of occurrence or the consequence of an accident or malfunction of equipment previously evaluated in the Safety Analysis Report has not been increased. This modification does not involve an unreviewed safety question per the criteria of 10 CFR 50.59.

Modificatio_n - Small Tool Decontamination Trailer Ventilation System (B/A 412261)

Description of Modification:

This modification converted the temporary ventilation system for the Small Tool Decontamination Trailer into a permanent installation. The permanent system utilized new ductwork from the roof openings of the Decon Trailer, through the opening in the west wall of the Auxiliary Building, to the connection with the Auxiliary / Fuel Handling exhaust duct.

Safety Evaluation Summary:

The Small Tool Decon Trailer ventilation system collects air from the Decon Trailer laboratory hoods and directs it into th.e Auxiliary Building returr air ductwork. It then mixes with other plant exhaust air and flows through the Auxiliary / Fuel Handling Building charcoal filter before being discharged to the atmosphere through the main plant vent. This modificatf or, ties the Decon Trailer ventilation system to the Auxiliary / Fuel Handling Building ventilation system, such that the approximately 2500 cfm design flow is provided by the main plant exhaust fans AH-E-14A-D. The ventilation requirements for the Decon Trailer are within the design basis for the Auxiliary / Fuel Building ventilation system and thus will not impact the existing system. The modification's design and installation criteria meet the applicable TMI-l requirements.

As a result, the probability of occurrence or the congquence of an accident or malfunction 6f equipment previously evaluated in the Safety Analysis Report has not been increased. This subject modification does not involve an unreviewed safety question per the criteria of 10 CFR 50.59.

Modification - B/A 412325 - Chemical Addition Modification for the Waste Evaporator Condensate Storage Tank Description of Modification:

This modification provided chemical feed piping and equipnent for pH control of the liquid radwaste in the waste evaporator condensate storage tanks WDL-T-11 A/B. Prior to implementing this modification, chemical addition was accomplished by manual feed. A portable pumping unit and associated feed line were installed.

Safety Evaluation Summary:

This modification provided a permanent system for adding the required chemicals to control pH in the waste evaporator condensate storage tanks WDL-T-11 A/B. The modification complies with all applicable regulatory and system design requirements for TMI-1. Proper pH control is essential for the liquid radwaste system operation. This modification allows the pH to be controlled within the prescribed limits.

As a result, the probability of occurrence or the consequence of an accident or nelfunction of equipment previously evaluated in the Safety Analysis Report, has not been increased. It is, therefore, concluded that the . subject modification does not involve an unreviewed safety operation per the criteria of 10 CFR 50.59.

4 Modification - B/A 412172 - Liquid Radwaste Pungs WDL-P-14A/B Upgrade Description of Modification:

The existing liquid radwaste pumps WDL-P-14A/B were replaced with new larger capacity pumps (60 gpm vs. 30 gpm). The larger capacity pumps increase the capability to mix the waste evaporator condensate tanks WDL-T-ll A/B.

Thorough mixing is required to provide an accurate sample of the tank contents prior to transfer of the mixture and/or release to the environment.

Safety Evaluation Summary:

Replacement of the existing radwaste pumps WDL-P-14A/B improves the reliability and operability of the liquid radwaste punps. Insufficient mixing in Tanks WDL-T-ll A/B due to the undersized pumps has been eliminated by the higher capacity replacenent pumps. This ensures an accurate sample of the tank contents. The design and installation of the new pumps is consistent ifith the design basis for the liquid radwaste pumps.

As a result, the probability of occurrence or the consequences of an accident or nelfunction of equipment previously evaluated in the Safety Analysis Report, has not been increased. It is, therefore, concluded that the subject modification does not involve an unreviewed safety operation per the criteria of 10 CFR 50.59.

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Modification - B/A 412291 - Chemical Addition Modification for Concentrated Waste Storage Tank Description of Modification:

This modification provided chemical feed piping and equipnent for pH control of the liquid radwaste in the concentrated waste storage tanks WDL-T-6A/8.

Prior to implementing this modification, chemical addition was accomplished by manual feed. A portable pumping unit and associated feed line were installed to introduce the required chemicals for pH control.

Safety Evaluation Summary:

This modification provided a permanent system for adding the required chemicals to control pH in the concentrated waste storage tanks WDL-T-6A/8.

The modification complies with all applicable regulatory and system design requirements for TMI-1. Proper pH control is essential for the liquid radwaste system operation. This modification allows the pH to be controlled within the prescribed limits.

As a result, the probability of occurrence or the consequence of an accident or malfunction of equipment previously evaluated in the Safety Analysis Report, has not been increased. It is, therefore, concluded that the subject modification does not involve an unreviewed safety operation per the criteria of 10 CFR 50.59.

Modification - B/A 412021 - Reactor Coolant System High Point Vents Description of Modification:

This modification f r. stalled 1/2" vent piping and valves at the following points in the Reactor Coolant System:

- The top of each Hot Leg (2 total)

- The top of the Pressurizer

- The top of the Reactor Vessel

- The top of the Reactor Coolant Drain Tank Piping for these vents is routed to various points outside the "D" ring where they discharge to containment atmosphere. The instrumentation and controls for these vents required installation of switches and position indication lights on panel "PC" in the control room. Each vent line is equipped with a differential pressure flow orifice and differential pressure transmitter which also provides indication to lights installed on panel "PC."

Safety Evaluation Summary:

The requirements for Reactor Coolant System Venting is documented in 10 CFR 50.44, NUREG 737 (Section II.B.1), and the TMI Restart Report (Section 2.1.2.2). All vents are located in the Reactor Building and are operable from the control room. This modification enhances plant safety by providing the capability of venting non-condensible gases from the Reactor Coolant System, thereby promoting natural circulation cooling and by increasing the plants ability to deal with large quantities of non-condensible gas.

All piping, valves, conduit and associated supports have been designed and installed in accordance with Seismic Category I criteria. Electrical and instrumentation installation is Class IE. The engineering and installation of this modification was performed as Important to Safety / Nuclear Safety Related. The probability of occurrence or consequence of an accident or malfunction of equipment previously evaluated in the Safety Analysis Report has not been increased. This modification does not involve an unreviewed safety question per the criteria of 10 CFR 50.59. '

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Modification - B/A 123100 - Diesel Generator Differential Relay Replacement Description of Modification:

INP0 SER 18-84 advised that General Electric Model CFD relays used for differential protection of the diesel generators are not seismically qualified. TMI-l used these relays in both diesel generators. As corrective action for LER 84-005-00 submitted August 15, 1984, the CFD relays have been re-placed with seismically qualified BBC 87M relays.

Safety Evaluation Summary:

This modification provides the resolution of LER 84-005 00. The replacement of the CFD relays does not degrade the 4KV engineered safeguards system. This modification does not constitute an unresolved safe question as defined by 10 CFR 50.59.

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m Modification - B/A 412023 - Installation of Reactor Coolant Inventory Trending System (RCITS)

Description of Modification:

The water level trending portion of the RCITS reasures the water level from the bottom to the top of the reactor coolant loop A and B hot leg pipes and measures the water level from the bottom of the hot leg pipes to the reactor vessel head vent nozzle. This is accomplished by two differential pressure transmitters installed between an upper connection at the top of the steam generator hot legs and a lower connection upstream of the decay heat line isolation valve (DH-V-1), and by two differential pressure transmitters installed between an upper connection at the reactor vessel head vent valves and a lower connection upstream of valve DH-V-1. The upper connection for the r transmitters is equipped with a condensate pot and provides a water column reference leg for the transmitter. Resistance temperature detectors measure the temperature of the water in the reference leg. A thermocouple measures the temperature of the reactor coolant to compensate for density changes. The density compensated level output is displayed via the plant computer.

The void fraction trending portion of the RCITS transmits RC purp power signals to the plant computer where these are converted to void fractions via dn empirical algorithm utilizing RCP power, pump status and RCS cold leg temperature data. This is acconplished by four isolated signal transmitters mounted in the RCP Power Monitor Rack A which receive input from an existing

{ watt-transducer and provides a non-lE pump power signal to the plant computer.

_ Safety Evaluation Summary:

The RCITS provides a reans for the Control Room operator to monitor the water

. inventory of the Reactor Coolant System (RCS). The RCITS is operational when the reactor coolant pumps are on or off. Displayed water inventory data with the pumps off is useful as confirmatory information to other instrumentation

_ of conditions which ney interrupt natural circulation leading to a potential umdequate Core Cooling (ICC) event. The RCITS also provides a neans for the control room operator to monitor the void content of the RCS when the pumps

- a re ru nni ng. Displayed void fraction data provided by the RCITS will be

, useful as anticipatory information of conditions which may interrupt nornal E circulation.

r Note that this system is installed but is not operational pending NRC approval of operating requirements.

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Procedure M-155, Main Steam Relief Support System Clearance Readings Description of Procedure Change,:

Changed feeler. gauge length and thickness; provided allowance to perform measurements at 6 month intervals, instead of one month; specified area over which clearance readings must be within limits. -

Safety Evaluation Summary:

Results of testing during the Restart Test Program supported by engineering analysis provide assurance that these procedure changes achieve additional personnel safety without compromising the capability of the Main Steam Relief Support System to perform its safety function.

Procedure 1101-4, Balance of Plant Setpoints Description of Procedure Change:

Revise Setpoint cf MS-V6 (EF-P1 Steam Supply Pressure Regulating Valve) from 175 psig to 150-160 psig to prevent the periodic lif ting of MS-V228 (relief valve) when EF-P1 is operated on Main Steam.

Safety Evaluation Summary:

Analysis indicates EF-P1 will perform its design function at an inlet steam pressure as low as 140 psig. The 150-160 psig inlet steam pressure setpoint can produce the required 835 horsepower which is sufficient to deliver in excess of 400 gpm to the Once-Through Steam Generators.

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Procedure 1101-1, Plant Limits and Precautions Description of Procedure Change:

Change maximum OTSG allowable operating range level limit from 82.5% to 92%

during power operations, to provide for apparent OTSG fouling.

Safety Evaluation Summary:

Analysis of Babcock & Wilcox and GPU Nuclear show that no unreviewed safety question is involved. An assuned inventory of 55,000 lbs was used for the Main Steam Line Break analysis in the FSAR, and is greater than the total inventory in the steam generator as calculated for a steam generator with 1,217 tubes removed from service and operated at 92% operating range level. A small percentage increase in true inventory in the steam generator due to tube plugging and operating level increase will not make the previous MSLB analysis invalid.