ML13324A485
| ML13324A485 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/26/1984 |
| From: | Haynes J SOUTHERN CALIFORNIA EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8411090251 | |
| Download: ML13324A485 (3) | |
Text
Southern California Edison Company SAN ONOFRE NUCLEAR GENERATING STAT-I6N PKT 3f P.O. BOX 128 SAN CLEMENTE, CALIFORNIA 92672 J. G. HAYNES TELEPHONE STATION MANAGER October 26, 1984 (714) 492-7700 U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 IE HQ FILE -op Attention:
Mr. J. B. Martin, Regional Administrator
Dear Sir:
Subject:
Docket Nos0,-206 0-361 and 50-362 NRC Fire on Inspection Report Open Items San Onofre Nuclear Generating Station, Units 1, 2 and 3
References:
(1) NRC Inspection Report Nos. 50-206/84-01, 50-361/84-01 and 50-362/84-01 (2) Letter, J. G. Haynes (SCE) to J. B. Martin (NRC), Special Report, dated November 8, 1983 (3) NRC Inspection Report No. 50-206/84-16 (4) Licensee Event Report 83-140 (Docket No. 50-361),
dated November 28, 1983 The purpose of this letter is to provide the information requested by Mr. K. Scown of your staff in Reference (1).
Investigation of these items has been performed and the results are discussed below.
Containment Fire Protection Spray Header Reference (2) reported that on September 28, 1983, the Containment Fire Protection Spray Header had failed its routine air flow surveillance test required by Technical Specification 4.15.B.(4).
An investigation determined that approximately 20 nozzles were clogged with corrosion products due to leakage around the valve seat of CV-92.
References (1) and (3) subsequently discussed commitments made by SCE to perform an engineering evaluation to determine a method to prevent corrosion build-up in the system and to identify corrective measures taken.
The results of the engineering evaluation showed that CV-92 is designed for no measurable leakage up to 150 psig. Upon disassembly of the valve, it was discovered that the rubber liner which forms the valve seat was worn and it has since been replaced. The valve was satisfactorily air tested and is being reinstalled in the system. A design modification will be completed during the next refueling outage to install an orificed drain valve downstream of CV-82, CV-92, and CV-114 sized such that the spray header flow requirements will not be impacted, however, a continuous drain path will be provided for any future leakage.
9411090251 841026 PDR ADOCK 05000206 G
Mr. J. B. Martin
-2 Fire Pump P221 Reference (1) requested additional information regarding Reference (4) on an October 27, 1983 incident in which the local controller shutoff switch for the electrically driven Fire Pump P221 was discovered to be open.
P221 was discovered to be inoperable at 0756 on October 27, when Fire Pump P222 autostarted due to a spurious sprinkler actuation.
P221 is designed to start prior to P222, however, in this instance, no actuation of P221 occurred. At that time, the local shutoff switch was discovered to be open, rendering P221 inoperable.
An investigation has been performed to determine when,the shutoff switch was opened, by whom, and the purpose for doing so.
P221 was verified to have been operational at 1310 on October 26, 1983, when the pump autostarted due to a service water demand and operated as required. The pump was secured at 1320 on the same day.
On October 27 at 0430, an acid leak occurred at the Make-up Demineralizer, and a Shift Supervisors Accelerated Maintenance Action (SSAM) was declared in order to expedite cleanup. Apparently, P222 was manually started for cleanup, and it is suspected that the shutoff switch was opened at that time in order to prevent autostarts of P221 while P222 was being used.
Although the person responsible for manipulating the switch cannot be determined, the period of inoperability has been reconfirmed to be between 1320 on October 26 and 0935 on October 27. A sign has been placed near each fire pump local controller shutoff switch warning personnel that operation of this switch can prevent automatic start of the fire pump.
No further action is planned.
Reactor Coolant Pump Oil Collection System Reference (1) requested additional information regarding the Reactor Coolant Pump (RCP) Oil Collection System wherein a portion of the RCP P003 oil splash shield was missing and RCP's P002 and P004 had approximately six inches of oil in their oil collection tanks. An investigation was performed to determine the facts leading to these two conditions.
Investigation has determined that the splash shield was originally installed as required by the License Condition. A complete system walkdown had been performed on November 4, 1982, and no remaining work items related to the oil splash shields were noted. Since no work was underway at the time the splash shield was identified as being removed, it is suspected this splash shield was removed while performing earlier maintenance on the system and not reinstalled upon completion of work. A new work order was issued on January 25, 1984, and the missing oil splash shield was replaced. The work was completed on February 7, 1984.
Mr. J. B. Martin
-3 On December 21, 1983, TCN 10-53 was issued for Operating Instruction S023-3-1.4, "Filling and Venting the Reactor Coolant System," which added a step requiring verification that no fluid is present in the oil collection tanks, and to drain the tanks when fluid is found. This surveillance cannot be performed routinely because the area is inaccessible while the plant is at power. The oil collection tanks are most likely to accumulate significant amounts of oil during periods of maintenance on the RCP's.
For this reason it was determined that the most appropriate time to check for fluid level would be while filling and venting the Reactor Coolant System at the completion of RCP maintenance. The oil collection tanks are capable of collecting more than 100% of the capacity of the RCP lube oil systems. Normal minor leakage would therefore not displace a volume sufficient to prevent the oil collection tank from completing its safety function provided the oil collection tanks are drained during any RCP maintenance in which replacement oil is added. The oil found in the RCP holding tanks on January 11, 1984, was due to normal minor leakage and was not removed because the surveillance requirement to check for oil in the tanks, scheduled for January 12, 1984, had not yet been performed.
The six inches of oil represented approximately 10% of the oil collection tank capacity. The oil collection tank had additional capacity to displace the entire RCP lube oil system for both associated RCP's. We conclude that this frequency is appropriate and no further actions are planned.
If you require any additional information, please so advise.
Sincerely, cc:
F. R. Huey (USNRC Senior Resident Inspector, Units 1, 2 and 3)
J. P. Stewart (USNRC Resident Inspector, Units 2 and 3)
A. J. D'Angelo (USNRC Resident Inspector, Unit 1)
U. S. Nuclear Regulatory Commission Document Control Desk Institute of Nuclear Power Operations (INPO)