ML20090B228
| ML20090B228 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 07/06/1984 |
| From: | Martin J WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| NUDOCS 8407120384 | |
| Download: ML20090B228 (5) | |
Text
Washington Public Power Supply System P.O. Box 968 3000 George Washington Way Richland, Washington 99352 (509)372-5000 Docket No.
50-397 July 6, 1984 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
NUCLEAR PLANT NO. 2 REPORT OF PLANT CHEMISTRY EXCURSIONS
Dear Sir:
The WNP-2 Plant provided verbal notification of plant shutdown due to high conductivity at 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br /> on June 9,1984.
This letter is the follow-up report of that event and one occurring on June 3,1984.
An inhouse review of this event and a similar one which occurred on June 3,1984 has been completed and both incidents have been evaluated
'not reportable'.
The bases for this detennination are included as to this letter.
Consequently, the report of the event occurring on June 9,
1984, is for information purposes only and included as Attachment 2.
It is the Plant Staff's belief that the results of this evaluation cor-rectly reflect the intent of Technical Specifications and the reporting requirements of 10CFR50.73.
Since this evaluation includes some inter-pretation of requirements, it is requested that further clarification be provided by the Comi ssion if there is disagreement with the position taken.
Very truly yours, i
l 4
f-J. D. Ma in (M/D 927 )
WNP-2 Plant _ Manager JDM:mm 8407120304 840706 i
i PDR ADOCK 05000397
Enclosure:
s PDR Attachments 1 and 2 cc:
Mr. John B. Martin, Administrator Region V, Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission 1450 Maria Lane Walnut Creek, California 94596
(
Mr. A. D. Toth, NRC Resident Inspector (901 A) gf,%
i v
ATTACHMENT 1
Background
At 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> on 6/2/84, with the Reactor operating in Mode 1 at 30% power (200 MWe gross) an increase in coolant conductivity was noted and measures were taken to reduce levels.
Conductivity levels exceeded 1.0 umho/cm at 2113 hours0.0245 days <br />0.587 hours <br />0.00349 weeks <br />8.039965e-4 months <br /> and the Plant entered Technical Specification Action Statement 3.4.4.a.1.
Conductivity continued to increase on 6/3/84 despite efforts to reduce levels and power reduction was initiated at 1540 hours0.0178 days <br />0.428 hours <br />0.00255 weeks <br />5.8597e-4 months <br /> on 6/3/84 with conductivity level of 6 umho/cm.
The NRC was subsequently notified at 2132 on 6/3/84 (courtesy call only) of Plant shutdown.
Following inspections of the condenser on 6/5/84, tube leakage was confirmed due to steam impingement.
A total of 13 condenser tubes were plugged and a baffle plate was added.
The cause of jet impingement was determined to be due to steam leakage into the condenser from bypass valves around traps in the Main Steam System.
These lines discharge to condenser nozzle #128 v:hich included an internal baffle designed to handle water and not steam.
The repairs to the condenser were completed and preparations were made for startup.
On 6/8/84 at approximately 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br /> with the Plant in Startup (Mode 2) with power at 4%, conductivity again began to increase as described in Attachment 2.
The cause of that increase, as described in the attachment was found to be 6 sheared tubes along with the presence of a loosened baffle plate from condenser nozzle #41 (RFW-FCV-15 long cycle cleanup line to the main condenser).
This condition was verbally reported to the Commission at 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br /> on June 9, 1984.
Evaluation of P.eportability The shutdown on 6/3/84 was initiated by the Plant while in Action Statement 3.4.4.a.l.
Plant shutdown was completed approximately 25-1/2 hours after levels reached the limit of 1 umho/cm.
In accordance with the provisions of the Action Statement, it was determined that the condition was not reportable.
The shutdown on 6/9/84 was initiated by the Plant staff while in Technical Specifi-cation Action Statement b (mode 2) and shutdown was completed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of detecting increasing conductivity levels.
This shutdown was reported to the NRC in accordance with 10CFR50.72(b)(1)(1)( A), however, the LC0 Action Statement time limit had not been reached.
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Conclusion Based on the Plant staff's understanding of Technical Specifications and reporting requirements, it has been concluded that a reportable condition does not exist if shutdown is initiated prior to reaching the established time limit which requires shutdown (i.e., Technical Specification required shutdown is not required).
This position is supported by responses provided in NUREG 1022, Supplement No.
1,Section II, Nos. 1.1, 1. 2, 2.1 and 2. 2.
Whenever the Plant is shutdown as a result of a condition which is addressed by the Technical Specifications and the shutdown is performed to comply with an Action Statement, a reportable condition per 10CFR50.72(b)(1)(1)(A) will exist.
Shutdowns which are initiated before the Action Statement requires shutdown are not report-able per 10CFR50.72(b)(1)(i)(A).
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ATTACHMENT 2
Background
On 6/8/84 at about 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br /> on startup return to power from shutdown, with the Plant in Mode 2 at 4% power an abnormal increase in Reactor water conductivity was observed on the Control Room Reactor Water Conducitivty Recorder.
Operations as-sessed the increase as a condenser leak and initiated confirmatic,n through chem-istry and other installed instrumentation.
The conductivity increase continued and required Plant shutdown.
Subsequent investigation revealed six sheared condenser tubes as a result of impact from loosened baffle plate on condenser nozzle #41 (condensate long-cycle cleanup valve).
Immediate Corrective Action The Control Room staff took action to ameliorate the impact of the assessed major i
tube leak by restricting further contaminated feedwater and CRD inputs, isolating the condensate storage system contamination and placing the Reactor into a cold shutdown condition. Major actions were as follows.
l 6/8/84 2330 Reactor water conductivity increase noted - Chemistry alerted -
Radwaste Control Room contacted.
2337 Closed condensate valve 17 to avoid contamination of 800,000 gallons of good condensate.
2348 Isolated "A" water box since tube sheet conductivity had shown high level.
r 6/9/84 0005 Initiated a Reactor shutdown by inserting rods, i
0009 Switched CRD from contaminated condensate to condensate storage I
input.
0016 Reactor water conductivity at about 10 umho/cm.
0025 RCIC initiated to feed condensate storage tank water versus contaminated feedwater injection.
0032 RHR "B" placed in service for shutdown.
0106 Reactor water conductivity peaked at about 29 umho/cm; chloride at 440 ppb, pH 9.8; Reactor pressure 340 psi, 430*F.
0122 Secured circulating water pump 18 and water box B.
0227 Broke condenser vacuum.
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t-t 0247 Drained condenser water boxes.
0325 Placed mode switch in shutdown, 380, 200 psi.
1300 Condenser hotwell entered and 6 sheared tubes observed along l
with presence of loosened baffle plate from condenser nozzle
- 41 (RFW-FCV-15 bypass condensate line to main condenser).
1808 Cold shutdown achieved.
I 1838 All chemistry parameters within Technical Specification limits.
l Chemistry staff tracked chemistry parameters thoughout the event.
Operations staff were precoating demineralizer units as rapidly as possible during the vent and initiated cleanup measures thereafter.
Further Corrective Action The affected condenser baffle plate and nozzle were reworked and the remaining con-denser baffle plates and nozzles were reviewed against design and operational char-acteristics.
Several additional condenser return lines were reworked to strengthen their integrity as a result of this review.
i Safety Significance The 29 umho/cm conductivity level in conjunction with the only slightly elevated chloride maximum level of 440 ppb at the pH of 9.5 to 10 were judged to not have a major safet,y significance, because the length of time and relatively low tempera-tures during which the chemistry problems existed were within the design basis of the Reactor Coolant System.
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