ML20237C566
| ML20237C566 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 08/17/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20237C561 | List: |
| References | |
| NUDOCS 9808210275 | |
| Download: ML20237C566 (4) | |
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2 UNITER; 8iATES
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 3000H001
.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION LICENSEE REQUEST FOR EXEMPTION FROM SECTION lil.O OF APPENDIX R TO 10 CFR PART 50 WATERFORD STEAM El FCTRIC STATION. UNIT 3 i
1.0 INTRODUCTION
Appendix R, " Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1,1979," to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, establishes fire protection features required to satisfy General Design Criterion 3, " Fire protection," of
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Appendix A to 10 CFR Part 50 with respect to certain generic issues for nuclear power plants licensed to operate prior to January 1,1979. Section 50.48 of 10 CFR Part 50 specifies that Appendix R applies to nuclear power plants licensed to operate prior to January 1,1979.
Since Waterford Steam Electric Station Unit 3 (Waterford 3) was licensed to operate on March 16,1985, Appendix R did not apply to Waterford 3. However, by letter dated November 10,1981, Louisiana Power & Light committed to meet the technical requirements of Appendix R to 10 CFR Part 50.
By letter dated February 19,1997, as supplemented by letters dated May 20 and July 25,1997, Entergy Operations Inc., ( licensee), requested an exemption from certain technical requirements of Appendix R, Section 111.0, " Oil collection system for reactor coolant pump."
The staff treated the exemption request as a deviation from the commitment to meet Section Ill.O of Appendix R. The exemption request will hereafter be referred to as a " deviation request".
2.0 DEVIATION REQUESTED The licensee requested a deviation from the technical requirements of Section 111.0 of Appendix R to the extent that it specifies that the reactor coolant pump (RCP) lube oil fill lines be protected by a lube oil collection system.
3.0 DISCUSSION Section Ill.O of Appendix R specifies that the RCP be equipped with an oil collection system if the containment is not inerted during normal operation. It also specifies that the oil collection system be capable of collecting lube oil from all pressurized and unpressurized leakage sites in the RCP lube oil systems. The leakage points to be protected include the lift pump and piping, overflow lines, lube oil cooler, oil fill and drain lines and plugs, flanged connections on oil lines, and lube oil reservoirs where such features exist on the RCPs.
ENCLOSURE 9808210275 980817 PDR j
ADOCK 05000382 POR i
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2 The underlying purpose of Section 111.0 of Appendix R is to provide reasonable assurance that leaking oil will not lead to a fire that could damage safety-related equipment during normal or I
design basis accident conditions.
Periodically, as a result of oil consumption during power operations, the licensee may need to add oil to the RCP motor lube oil reservoirs. Prior to 1986, the licensee accomplished oil addition by going into the containment building cavities (inside the D-rings) and adding the oil using the fill connection on the motor. This resulted in radiation exposure concerns for the personnel performing the oil addition. To reduce potential radiation exposure, the licensee installed a permanent gravity feed remote oil addition system that permits adding oil to the upper and lower reservoirs on the RCP motors from outside the D-rings during power operations.
The modification consisted of routing 1-inch diameter stainless steel tubing from the existing fill connections on the RCP motors up the inside of the D-rings, through the feedwater piping penetrations in the shield wall. The tMng terminated in a location adjacent to a hand pump.
The tubing is seismically supported. Flexible stainless steel hose connects the tubing to the RCP motor oil fill connection and allows for thermal movement and vibration. After completing the modification, the licensee performed a functional leak test. The remote oil fill lines are not provided with an oil collection system.
Any lube oil overflow at the RCP motor is collected by the existing collection system and routed to the applicable oil collection tank located outside of the D-ring. Due to the design of the remote fill!!nes, the system is empty except during oil addition activity. In order to minimize the potential for an oil fire due to a leak from the lines of the remote addition system, the licensee will take the following actions, by procedure, each time oil is added to an RCP lube oil reservoir:
The supervisor reviews the work package with the lead worker to ensure that the work instructions are fully understood prior to authorizing work.
Note: The following steps are performed by the maintenance personnel assigned to add oil.
Check and record upper and/or lower lube oil reservoir oil level (s), as applicable, via the Plant Monitoring Computer (PMC) or by calling the control room.
Use the empirically derived (volume vs % level) chart from Technical Manual 45700016t, Vol.2, to determine the amount of oil to be added. The reservoir level should be raised to approximately 75%.
On the way up to add oil, observe the minus 11 feet elevation, under the applicable RCP, and document the presence of any oil pooling on the floor or other evidence of oil leakage. Document the findings (approximate amount of oil).
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3 Add the amount of oil required as determined from the chart.
Obtain Operations concurrence and drain oil from the applicable oil collection tank. This is to assure that the tank has room to hold the lube oil volume of an RCP.
On the way out of containment, observe the minus 11 feet elevation, under the applicable RCP, and document the presence of oil pooling on the floor or other evidence of oil leakage. Document the findings (approximate amount of oil).
After leaving containment, verify (from PMC or by calling the control room) that the expected rise in reservoir level occurred as a result of oil addition.
If the oil level increase is not representative of the amount of oil added, notify the RCP System engineer and determine if there was an oil leak invc!ved.
The licensee stated that a single 5 gallon container of oil would be the most likely volume of oil brought in to add oil to an RCP lube oil reservoir at power, and the maximum credible oil addition volume would be 20 gallons. The licensee further stated that 20 gallons is a conservative, estimated volume since normally very little oil is required to be added to the RCP lube oil reservoirs at power. During the last refueling cycle, no oil was added during power operations.
Thermal heat detection systems and manual pre-action sprinkler systems are provided for the RCPs. The detectors alarm in the control room. The detection system provides early waming of possible fire conditions and the sprinkler system is designed to control the spread of fire, if one were to occur. The sprinkler systems are installed inside each RCP cavity inside the D-rings to protect the RCPs and motors in case of a fire. Manual actuation pull stations are located in the control room and at the sprinkler control valve.
4.0 EVALUATION The principal safety concerns regarding the installation of remote fill lines are that overfilling of the lube oil system or damage to the tubing and/or flexible hose could result in an oil leak into the containment during the addition of oil. The leaking oil could ignite and the resulting fire could damage safety-related equipment or adversely affect the ability to achieve and maintain post-fire safe-shutdown conditions.
Shutdown equipment in the vicinity of the RCPs is limited to steam generator pressure indication. If an unmitigated fire resulting from oil spill were 'to occur, safe shutdown cooling could be monitored by pressure transmitters located on the main steam lines outside of containment.
The remote oil filllines are empty except for the duration of the fill activity. The measures that will be taken during oil filling, the lack of oil fill system pressurization, and the limited potential fire size from the volumes of oil typically added during power operations, provide reasonable assurance that significant damage would not occur in the containment building from a worst-f
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case postulated fire. If a lube oil leak were to occur from the remote oil fill lines, it would occur during oil fill activity when procedures specify that personnel check for oil under the RCPs upon entering and leaving containment. The oil spill would therefore be promptly identified, allowing the licensee to take appropriate corrective actions.
Fire detection and manual fire suppression equipment are available in the vicinity of the remote oil fill lines. In the event of a fire, it is expected that the detectors will alarm in the control room.
The sprinkler system and the fire brigade would control and extinguish the fire. This provides further assurance that a worst-case postulated fire would not cause significant damage to safety-related equipment or adversely impact the post-fire safe-shutdown capability.
5.0 CONCLUSION
On the basis of its evaluation, the staff concluded that an oil collection system is not needed for the subject RCP lube oil filllines to meet the underlying purpose of Section Ill. O of Appendix R to 10 CFR Part 50. Therefore, the lack of an oil collection system for the RCP lube oil remote fill lines is an acceptable deviation from the technical requirements of Section 111.0 of Appendix R to 10 CFR Part 50. The licensee's request for deviation is, therefore, acceptable.
Principal Contributor: Daniele Oudinot Date: August 17, 1998 1
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