ML20207K999

Requests Deviation from Approved Fire Protection Program as Delineated in License Condition 2.C (14) for Unit 2 & 2.C (12) for Unit 3

ML20207K999
Person / Time
Site:	San Onofre
Issue date:	03/11/1999
From:	Scherer A SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9903170330
Download: ML20207K999 (12)

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• Company March 11, 1999 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

Docket Nos. 50-361 and 50-362 Deviation Request from the Southern California Edison Company's Commitment to 10 CFR 50 Appendix R, Section III.0 San Onofre Nuclear Generating Station Units 2 and 3.

Gentlemen:

J 1he Southern California Edison Company (SCE) requests a deviation from SCE's approved fire protection program as delineated in License Conditions 2.C (14) l for Unit 2 and 2.C (12) for Unit 3. The approved fire protection program i includes a commitment to the requirements of Section III.0 of 10 CFR 50 l Appendix R to the extent that it requires oil collection systems for reactor j coolant pumps (RCPs) to be capable of collecting lube oil from all potential unpressurized leakage sites, including oil fill lines. The request is for San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. The description below and in the Enclosure is of the Unit 2 RCP remote oil fill line configurations. Unit 3 is similar in all material aspects.

Remote oil fill lines to the SONGS Unit 2 RCP lub3 oil systems were connected during the Cycle 10 refueling outage, which ended February 26, 1999. However, the covers are currnntly shut to prevent their use pending NRC approval of the enclosed deviation yequest. SCE plans to connect the Unit 3 remote oil fill lines during the upcoming Cycle 10 refueling outage. These lines, which extend from the 45 foot elevation walkway adjacent to the RCP motor to the oil f/

fill line connections on the RCPs, were installed to reduce radiation exposure /[

and personnel safety hazards to workers who periodicclly add oil to the RCP lube oil systems during power operation.

It is noted that these remote oil fill lines were connected and used prior to 1997. In 1997 these lines were disconnected following interactions with the NRC staff and an SCE evaluation. Since that time, however, the NRC staff has approved the use of similar remote oil fill lines for other nuclear plants.

9903170330 990311 ~

PDR ADOCK 05000361 F PDR P. O. Box 128 San Clememe, CA 92674 0128 949-368-7101 Fn 949-3684575

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Document Control Desk '

Therefo're, based upon recent interpretations of the NRC Staff, SCE has concluded that this deviation request for the remote oil fill lines is appropriate. The enclosed request provides justification for such a deviation. In. addition, the enclosed request shows that the configuration of the remote oil fill lines, as designed, does not adversely affect the ability l to achieve and maintain safe shutdown of the plant in the event of a single fire, as required by 10 CFR 50 Appendix R.

4 The fire protection rule (10 CFR 50.48 and 10 CFR 50 Appendix R) became effective on February 19, 1981. Appendix R was only directly applicable to nuclear plants that had operating licenses on or before January 1,1979.

However, prior to the granting of a low power license for Unit 3 and a full power license to operate Unit 2, the NRC determined that all future licensees (for licenses issued after January 1,1979) would also have to commit to meet specific portiens of Appendix R requirements. The SONGS commitment to the specific portions of Appendix R was incorporated into the fire protection program as delineated in License Conditions 2.C (14) for Unit 2 and 2.C (12) for Unit 3. Because Appendix R did not apply to SONGS Units 2 and 3 based on the date of the license, SCE's compliance with Appendix R is by a commitment to specific portions of Appendix R. Therefore, SCE is requesting a deviation from the approved fire protection progr 3m as delineated in License Conditions 2.C (14) for Unit 2 and 2.C (12)for Unit 3 rather than requesting an exemption from the rule.

SCE is requesting expedited approval of this deviation request because of oil leakage currently observed on RCP 2P004. The existing oil collection system is fully compliant with Appendix R Section III.0 requirements for all ,

ootential leakage points during normal operation, and therefore, is designed '

to capture and channel this leakage to the oil collection tanks. Also, pu t operational inspections have confirmed the effectiveness of the lube oil collectica system.

However, since the 2P004 leakage rate is different from previous experience, SCE will perform a pre-planned inspection of potential oil leakage points  !

prior to any addition of oil. This inspection will take into account ALARA practices. Since the accumulated leakage to date is lest than three gallons, subsequent inspections may be necessary to fully ensure that no unacceptable leakage exists.

Oi. drain tank level accuracy is insufficient to verify the estimated three gallons leaked to date; however, it may be included in subsequent inspections.

The tank that 2P002 and 2P004 drain into will hold an excess capacity of greater than 90 gallons more than the contents of two RCP lube oil systems.

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Document Control Desk .

The enclosed request for deviation is based on a December 23, 1996, request from Arkansas Nuclear One. At the current rate of leakage from RCP 2P004 SCE will need to add oil on or before March 18, 1999. Therefore, NRC approval of this request is needed prior to that date to reduce personnel radiation exposure and eliminate a personnel safety fall hazard during this oil addition.

If you have any questions or would like additional information on this subject, please feel free to contact me or Jack Rainsberry at (949) 368-7420.

Sincerely, "W

Enclosure l cc: E. W. Merschoff, Regional Administrator, NRC Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 J. W. Clifford, NRC Project Manager, San Onofre Units 2 and 3

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ENCLOSURE REACTOR COOLANT PUMP REMOTE OIL FILL SYSTEM

RCP FILL Page 1 of 5 REACTOR COOLANT PUMP REMOTE OIL FILL SYSTEM Remote Oil Fill System Description As a result of oil consumption during power operations, the need arises to periodically add oil to the reactor coolant pump (RCP) motor lube oil lower reservoir. Previously, this was accomplished by transporting oil into the containment building cavities (inside the bic-shield) and adding the oil using ,

the oil fill connection on the motor. This resulted in bcth ALARA (an estimated I 600 mR per entry) and personnel safety concerns (e.g., heat stress, climbing unguarded structures, and stepping out onto a beam, while carrying and pouring thecontainersofoil).

In an effort to minimize radiation exposure to maintenance personnel and resolve the personnel safety concerns, a gravity feed, remote oil fill system was installed on each RCP motor. The system ccnsists of a covered hopper and stainless steel tubing at the 45' elevation adjacent to each RCP. The oil hopper is designed to accommodate up to a five gallon container of oil inserted upside down. After the container is inserted, the lid of the hopper will be closed. The oil container completely empties out while inside the hopper. So, there is no potential of spillage during filling. These fill hoppers are connected to each RCP motor lower reservoir fill connection - stainless steel tubing (3/8" Unit 2and1/2" Unit 3)andhighpressurecompressionfittings.

It is estimated that oil fill efforts using these hoppers will result in a reduced radiation exposure (from 600mR to n estimated 50 mR per entry) and reduced risk of physical injury.

These remote oil fill lines and hoppers are seismically mounted to remove any SeismicCategoryII/Iconcerns. The Stainless Steel (SS) tubing, the hopper, and the oil fill connection are all mounted on the motor to minimize the effect of any translated vibration and thermal movement. Not all of the SS tubing nce all of the hoppers are protected by an oil collection system. The connections to the motor lower reservoirs are protected by installed oil collection system pans. The maximum oil level in the reservoirs is lower than the oil fill connection.

These remote oil fill tubing runs are connected with high pressure compression fittings. Only one fitting per pg is not protected by an oil collection system. This type of fitting is hi aly 9 reliable, especially when used in low pressure or ventea applications, and not typically subject to leakage. The minimum slope of the installed tubing is 1/8" per 12" run. This ensures the system drains following each use and remains a dry system. (Twosketches depicting a typical remote oil fill line to a RCP are attached.)

The remote oil fill lines do not extend beyond the fire zone boundary where the RCP is located.

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! 1 l RCP FILL l

Page 2 of 5 01l Fill Process With the above described remote oil fill system, oil can be safely added to the

! RCP motor lower oil reservoirs. During each oil fill, the appropriate increase )

in reservoir level will be observed using a. level indication system. In each case, the resultant indicated change in level will verify that the oil reaches j the reservoir. Other administrative controls, as discussed under Compensatory l l Measures, will be in place to ensure any potential leakage is identified and I eliminated.

Consequences of Remote Oil Fill Potential Leakage  !

The routing of the remote oil fill lines, as described above, is from the side l of the RCP motor, under the grating, to the motor lower oil reservoir fill port.

The oil fill tubing is routed such that no leakage from the system could reach any fibrous blanket insulation located in the containment building. All insulation that potential leakage from the system could come into contact with is a stainless steel reflective type pipe insulation. The expected maximum temperature on this type of insulation is less than 200*F under worst case design conditions, and therefore, would not be an ignition source.

l The Unit 2 Containment Building is a reinforced concrete structure that houses the reactor, steam generators, reactor coolant pumps, reactor coolant system,

and other required support systems. The building is divided into three (3) principal fire areas, two of which do not contain any safe shutdown equipment.

The fire area containing safe shutdown equipment and cables is comprised of fire zones 2-CO-15-1A, 2-C0-15-18, 2-CO-15-1C, and 2-C0-63-10. Fire zones 2-C0-15-1A and 2-C0-15-1B are the steam generator rooms. Fire zone 2-C0-15-1C is the area

! outside the steam generator on elevations 15, 30, and 45 feet. Fire zone

[ 2-CO-63-1D is the operating floor at elevation 63 feet six inches. All four

fire zones are considered one fire area because of a number of unsealed floor l penetrations and the use of open metal grating as floors.

l Fire zones 2-CO-15-1A and 2-00-15-18, which contain RCPs, are the primary concern of this deviation request. The major in-situ combustibles located in fire zonas 2-CO-15-1A :Ind 18 are cable insulation and Reactor Coolant Pump (RCP) motor. lube oil located an the 45 foot elevation. Introduction of transient combustibles to the area is controlled by plant administrative procedures, and access is limited to the area during normal plant operation. Although these fire zones do not have zone wide fire detection, fixed temperature rate-of-rise heat detectors and a semi-automatic water spray system are located above the RCPs. In the unlikely event of a fire, the detectors will provide an alarm to the Control Rcom as well as the site Fire Department office to alert Operations to open the containment firewater isolation valve. In addition, manual fire suppression capability, consisting of portable extinguishers and hose stations, is available in adjacent fire zone 2-C0-15-1C.

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RCP FILL Page 3 of 5 The containment building is divided into fire areas for the purposes of evaluating the effects of fires. The zones were divided on the basis of clear space without intervening combustibles. The north half of the containment building outside the generator rooms contains cabling and equipment associated with safe shutdown that is separated from cabling and equipment ir, the south half of the containment building. The oil fill lines for thi. RCP motors are located in the steam generator rooms: fire zones 2-CO-15-1A (north) and 2-C0-15-1B (south). There are two RCPs in each steam generator room. The RCP remote fill tubing does not communicate outside the respective steam generator room. The effects of postulated oil loss inside the generator rooms during the oil fill evolution were specifically evaluated for each zone. Due to the separation of redundant components, the oil fill lines pose no threat to the safe shutdown capability.

Safe Shutdown Equipment Separation Safe shutdown equipment located in these fire areas includes the following:

• Steam generator pressure and level instrumentation and associated cables

• Reactor coolant temperature instrumentation and associated cables

• Pressurizer pressure and level instrumentation and associated cables i

The separatio: of these instruments and associated cables was previously I analyzed. The analysis demonstrated that for a fire in a Steam Generator I compartment, redundant instruments will not be affected and at least one I required channel will remain available for safe shutdown. The steam generator comparti ants block a direct path of fire between redundant cables as the cables J 1 eave the steam generator compartment. This separation, combined with the l physical barrier of the steam generator rooms during most of the cables' routing, makes it highly unlikely that a single fire will affect instrumentation j to both steam generators.  !

Pressurizer pressure and level instr ents are mounted on the outside of the steam generator compartment:;. Cables from the pressurizer pressure and pressurizer level instrurentation are all routed independently inside containment. It is highly unlikely that a fire of sufficient magnitude will I occur that will affect all channels of pressurizer pressure and level l instrumentation; therefore, at least ora channel of pressurizer pressure and l

, level indication will remain available for safe shutdown.

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RCP FILL Page 4 of 5 Below, the effects of a potential fire from a leak occurring during oil fill are {

analyzed. Oil leaks, if not captured by the lube oil collection system, would tend to migrate to the containment floor where it would flow to the equipment drains under the RCPs. The temperature of the equipment in the area will remain

-significantly below the auto-ignition temperature. Currently, Mobil, SHC 626 (synthetic) oil, which has an auto-ignition temperature of 720*F and a flash point of 440'F is used. Fixed temperature rate-of-rise type heat detectors are installed over each RCP in the steam generator rooms. The detection system l alarms 'are in the Control Room and the Fire Department office. The I semi-automatic suppression system is designed to control the spread of fire, if it did occur. Additionally, manual fire suppression equipment is readily available for responding to a fire. I Administrative limits will be set at a maximum of three (3) gallons of oil per oil fill. This will limit the amount of oil that is not contained in the onlikely event of an' oil leak. Given the RCP oil remote fill system is not l pressurized, the size of the generator room, and the limited size of the i postulated fire (three gallons of oil), the potential for fire is minimized, and the occurrence of damage to redundant instrumentation channels outside the ,

generator room is not credible.  ;

Due to system design (sloping lines that do not retain oil) and the process for j adding oil, the likelihood of an oil leak of three gallons is very remote.

Further, should a leak occur during filling, the amount of the oil leaked would l be much less than the contents from one RCP motor, which has been analyzed from a safe shutdown perspective and found to be acceptable. Therefore, in the unlikely event of a fire involving the maximum postulated lube oil leak from one RCP, the ability to achieve and' maintain safe shutdown is assured.

Compensatory Measures E

In order to minimize the potential for an oil fire due to a leak from the lines of the remote oil fill system that do not have an oil collection system, the following actions will be taken each time oil is added through this system:

Prior to each fill the remote oil fill lines will be visually inspected.

• Each remote oil fill will be limited to three gallons.

A level indicator (e.g., PMS computer) will be utilized to verify that the three gallons has reached the reservoir of the correct RCP motor (the oil level can be determined to within % qallon).

s RCP FILL

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. Subsequent to each fill the remote oil fill lines will be visually inspected for leakage.

. The total oil volume to be added will be limited to less than the amount calculated to result in an indicated reservoir level of 95*t.

• Should any oil leak, it will be removed prior to exiting the containment building.

• The remote oil fill lines will be inspected each outage in conjunction with the RCP lube oil system inspection.

If at any point during a remote fill operation it is determined that added oil is not reaching the desired location, the activity will be terminated, and the situation will be assessed. Personnel responsible for adding oil to the system also inspect for evidence of smoke following the oil fill. If smoke is detected, a fire brigade will be dispatched to the area. Fire suppression equipment is readily available for use in responding to such an event.

Conclusions The system is dry when not in use. When utilized, the Lapressurized system is limited to three gallons of oil per fill.

Although highly unlikely, oil that may leak from this system could fall onto metal reflective insulation protecting RCS piping. There is no fibrous material located in any postulated leak affected area. The maximum temperature of the surface of the SS insulation is well below the auto-ignition temperature of the oil. Therefore, no credible ignition source is present.

The design of the existing oil collection system and the RCP lube oil system, including the remote fill lines, ensure that oil leaking from the lube oil system is minimized and that any oil leakage is diverted to a safe location to prevent it from becoming a fire hazard.

Should a fire occur, no redundant trains of safe shutdown equipment will be affected due to the limited amount of oil available (three gallons) and the configuration of safe shutdown equipment.

Based on the above, the intent of 10 CFR 50 Appendix R (the ability to achieve and maintain safe shutdown of the plant in the event of a single fire) is accomplished without having a full oil collection system on the RCP remote oil fill system, l

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