ML20084R723

AO 50-249/75-02:on 750103,concentration of Chloride Ions in Reactor Coolant Determined Above Limiting Condition for Operation,Per Tech Specs.Caused by Inoperability of Reactor Coolant Cleanup Sys.Shutdowm Immediately Initiated

ML20084R723
Person / Time
Site:	Dresden
Issue date:	01/09/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084R721	List: ML20084R718 ML20084R723 ML20084R730
References
13-75, AO-50-249-75-02, AO-50-249-75-2, NUDOCS 8306150509
Download: ML20084R723 (2)

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. Morris, Illinois January 9, 1975 60450..v.gg*y yy d

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Mr. James G. Keppler, Regional Director - ],s . gCI Directorate of Regulatory Operations-Region III p/

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SUBJECT:

REPORT OF AE!OR'4AL OCCURRE!CE PER SECTION 6.6.A 0F ThT TECHNICAL SPECIPICATIONS

. CHLORIDE ICN C0"CErfRATION IM REACTOR COOLA!E GREATER THAN O.5 PARTS PER MILLIGN

References:

1) Regulatory Guide 1.16 Rev.1 Appendix A

2) Notification of Region III of AEC Regulatory Operations Telephone: Mr. P. Johnson, 1445 hours0.0167 days <br />0.401 hours <br />0.00239 weeks <br />5.498225e-4 months <br /> on January 6, 1975 Telegram Region III, 1552 hours0.018 days <br />0.431 hours <br />0.00257 weeks <br />5.90536e-4 months <br /> on January 6, 1975 Report Number: 50-249/1975-2 Report Date: January 10, 1975 Occurre'nce Date: January 3, 1975 Facility:- Dresden Nuclear Power Station, Morris, Illinois IDDEIFICATION OP OCCURRD:CE Th'e concentration of chloride ions in the reactor coolant was determined to be greater than 0 5 parts per million (ppa) during routine plant operation which is above the limiting condition for operation specified in Technical Specifications Section 3.6.C4.

- CONDITIONS - PRIOR TO OCCURRE* CE Prior to the occurrence unit 3 was operating at a steady load condition of 1173 Wt (376 IGo) with the reactor coolant clean-up' system out-of-service for scaintenance. No testing.was in progress.-

DMCRIPPION OF OCCURRE:CE

~ On January 2,1975 at 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br />, the unit 3 reactor coolant clean-up. system was removed frca acrvice for repairs to the 3-1201-1353 valve. In accordance with past practice, with a reactor clean-up systcm removed frca service,-

sampling and analysis of reactor coolant for conductivity and chloride

approximately every 4 ~ hours was . initiated on January 2,1975 at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br />..

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Mr. James G. Keppler Jahuary 10, 1975 At1330hoursonJanuary3,1975labanalysisindicatedareactorcooiant chloride ion concentration of 0.6 p p. Subsequent analyses at 1745 and-2140 hours on January 3, 1975 also indicated chloride ion concentrations of 0.5-0.6 ppm. Load reduction, at a rate of 20 :se/hr, was begun at 2050 hours0.0237 days <br />0.569 hours <br />0.00339 weeks <br />7.80025e-4 months <br /> on January 3, 1975 This rate was increased to 100 ige /hr at 2400 hours0.0278 days <br />0.667 hours <br />0.00397 weeks <br />9.132e-4 months <br /> on January 3, 1975. Chloride. concentrations decreased to less than 0 5 pp less than three hours following initial load reduction.

The unit was off system at 0259 hours0.003 days <br />0.0719 hours <br />4.282407e-4 weeks <br />9.85495e-5 months <br /> on January 4, 1975 and in_ cold shutdown at 0924 hours0.0107 days <br />0.257 hours <br />0.00153 weeks <br />3.51582e-4 months <br /> en that same day. +

DESIGNATION OF APPARENT CAUSE OF CCCURRENCE (Equiment Failure)

The single cause of the occurrence was the inoperability of the reactor coolant clean-up system. Extended maintenance on the 3-1201-135B valve prevented the clean-up system from being returned to service prior to l unit shutdown.

In addition, it is believed that there is a good probability that minor condenser tube leakage may exist. Condenser effluent (condensate) conductivity is being monitored to provide conclusive evidence in this area.

ANALYSIS OP OCCURRFl!CE Lab analyses indicated that chlorido concentration in the reactor coolant did not exceed 0.6 ppn and remained between 0 5-o.6 ppm for approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The presence of chloride in these concontrations presented no safcty probic.i in terma vi smge to the reactor or itel as determined from figure 4.6.2 in the Technical Specifications. The dissolved oxygen level in the coolant at shutdown (A worst case situation) was 0.2 ppm.

The health and. safety of the public was in no way endangered as a result t

of this occurrence.

CORRECTIVE 1.CTION Immediate corrective action was dictated by Technical Specification Section 3.6.C.5 sfnich states that an orderly shutdown is to be initiated when unable to maintain a chloride conecntration of less than 0 5 pm during normal operation. This shutdown was initiated at 2050 hours0.0237 days <br />0.569 hours <br />0.00339 weeks <br />7.80025e-4 months <br /> on January 3, 1975 The unit was off synter approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Inter and in cold chutdcen

, approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> alter the first indication of 0 5 ppn chloride.

1 Repair of the valve and other components was completed and the cler.nup system was returned to service.

PAILURE DATA A review of station records show that this is the first instance of chloride ion concentration increasing above limits during a cleanup system outage. I s

Sincepely, mM c c.b fftB.B.Stephenson l V Superintendent BBS:G'E: cmp

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