IR 05000373/1985028

Insp Repts 50-373/85-28 & 50-374/85-29 on 850827-1114.No Violation or Deviation Noted.Major Areas Inspected: Corrective Actions Taken as Result of LERs

ML20137H432
Person / Time
Site:	LaSalle
Issue date:	11/26/1985
From:	Danielson D, Schapker J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20137H408	List: IR 05000373/1985028 ML20137H403
References
50-373-85-28, 50-374-85-29, NUDOCS 8512020389
Download: ML20137H432 (5)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Reports No. 50-373/85028(DRS); 50-374/85029(DRS)

Docket Nos. 50-373; 50-374 Licenses No. NPF-11; NPF-18 Licensee:

Commonwealth Edison Company Post Office Box 767

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Chicago, IL 60690 Facility Name:

LaSalle County Station, Units 1 and 2 Inspection At:

LaSalle Site, Marseilles, IL Inspection Conducted:

August 27-28, September 11, 17, 20, October 15-16 and November 14, 1985 dngdn i /k ~

Inspector AJ. F. Schapker

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Approved By:

D. H. Danielson, Chief 1// 7- /J n

Materials and Processes Section Date Inspection Summary Inspection on August 27 through November 14, 1985 (Reports No. 50-373/85028(DRS);

and 50-374/85029(DRS))

Areas Inspected:

Routine, unannounced spection of Licensee Event reports and corrective action implemented by the licensee as a result of the events.

The inspection involved a total of 74 inspector-hours onsite and nine inspector-hours of in office review.

Results:

No violations or deviations were identified.

0512020 2 y M [ppgb73 PDft ADOCK

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DETAILS 1.

Persons Contacted Commonwealth Edison Company (Ceco)

R. D. Bishop, Services Superintendent

• D. S. Berkman, Assistant Superintendent, Technical Services D. A. Zoloty, Inservice Inspection Coordinator W. E. Sheldon, Assistant Superintendent for Maintenance D. E. Schaefer, General Foreman, Maintenance

• P. F. Manning, Technical Staff Supervisor

• R. M. Jeisy, Station QA Supervisor P. A. Baker, Technical Staff Engineer NRC

• M. J. Jordan, Senior Resident Inspector In addition to the above, the inspector contacted other licensee personnel during the course of the inspection.

• Denotes those present at the exit interview.

2.

Licensee Actions on LERs The Senior Resident Inspector requested assistance from the Division of Reactor Safety (DRS) due to the extent of work to be accomplished and the special expertise needed to determine the adequacy of the licensee's corrective action concerning the following LER's.

The DRS inspector determined that the licensee fulfilled their reporting requirements, and performed immediate corrective action to midigate the events.

Further action required by the licensee will be monitored through the resident inspectors and regional based inspectors as required.

a.

(Closed) LER 373/84-75-01:

The licensee issued an event report upon discovery of a leak around the 1B33-N023B Resistance Temperature Detector (RTD) during a hydrostatic pressure test of the Unit 1 "B" Reactor Recirculation system.

Subsequent visual inspection indicated a 180" circumferential crack in the thermowell body.

Further evaluation performed by the licensee's Station Material Analysis Department (SMAD)

determined the apparent cause of the cracking to be mechanical fatigue, possibly caused by turbulent flow conditions during operation of the Reactor Recirculation Pump (RRP).

The thermowells are located on the suction side piping of the RRP.

The licensee replaced the leaking thermowell and RTD with an identical unit.

The licensee plans to conduct a visual examination for evidence of leakage on each of the susceptible thermowells while their RTD elements are removed.

These examinations will be performed for both the Unit 1 and Unit 2 thermowells while the Recirculation system is

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subjected to operating pressure during each units first refueling outage (AIR 01-85-07015 and 67016).

Subsequent to these inspections the thermowells will be visually inspected as part of the normal hydrostatic pressure test performed during refueling outages.

Although the RTD elements are not removed during these examinations, the leaking thermowell was discovered during this type of hydrostatic test and will provide adequate asstrance of detection if similar cracking of additional thermowells occur.

The inspector reviewed the Final Safety Analysis Report (FSAR) and applicable Technical Specification for the LaSalle County Station and determined that in the event of a thermowell failure during normal operations the safety impact would be negligible.

The failure would render the P.TD inoperative, however, the consequence of this failure would not impact on the safe shutdown of the reactor as an identical RTD arrangement exists on the other Reactor Recirculation Loop (RRL).

There are two RRL's for each Reactor with cross over piping to each Loop.

The failure of the RTD would cause primary coolant to leak through to the RTD and subsequently leak through the threaded connection.

This would be detected as unidentified leakage by the Primary Containment floor sumps.

Subsequently, the RRL with the RTO thermowell failure would be isolated and the Reactor brought to safe shutdown through the other RRL, and repairs made.

The inspector reviewed the Work Request for the replacement of the deficient thermowell.

The repair was recomplished per the requirements of ASME Section III for Class I components.

The inspector reviewed the following procedures applicable to the repair:

Procedure Title Identification / Revision Weld Procedure Specification WPS-880/2 Cleaning Nuclear Materials LAP-300-16/3 Liquid Penetrant Examination NDT-D/10 Liquid Penetrant Appendix A/S Hydrotest LMP-RR-05/1 Visual Examination VT 2-1/0 The licensee's corrective action was adequate and was accomplished in accordance with Technical Specifications and Code requirements.

b.

(Closed) LER-05000374/85-027-00:

On May 27, 1985, at approximately 0030 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, with Unit 2 in Cold Shutdown at 0% power, the High Pressure Core Spray (HPCS) underground return line to the Cycled Condensate (CY) storage tank ruptured expelling approximately 200,000 gallons of CY water into the soil which surfaced near the Off Gas Filter Building.

The line was immediately isolated.

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results of the water revealed low but detectable contamination levels.

These levels were within 10 CFR 20 release limits.

The NRC

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Region III, Division of Radiation Safety and Safeguards (DRSS)

personnel are monitoring the radiological aspects of the release.

The HPCS system can supply water to the reactor vessel from either the CY storage tank or the Suppression Pool (NH) in the event of a loss of coolant accident. While the High Pressure Core Spray System is in the Normal / Standby Mode, its suction path is from the CY storage tank.

The system will automatically transfer to the NH when tank level is 1cw or a high water level condition exist in the NH.

Since HPCS suction piping from the CY tank is of the same piping design as the return line, it was also isolated until the failure mode of the return line was determined.

The isolation of the CY tank suction and return lines had no impact on the ability of the HPCS system to function, with the NH available as a suction source and therefor poses no safety concern.

The NRC inspector reviewed the construction records for the installation of the HPCS piping (suction and return lines to the CY tank) including the radiograph (RT) reports. Although some of the welds were rejected on the initial RT, the subsequent repairs and reexaminations were in compliance to the applicable code requirements.

The NRC inspector also reviewed reports of failure of the Reactor Coolant Isolation Cooling (RCIC) system suction and return lines to the CY tank which occurred during the construction phase.

The failure mode of the RCIC piping was contributed to schedule 10 stainless steel (ss) piping welded to schedule 40 (ss)

fittings causing welding induced defects which subsequently failed during hydrotest of the system.

This system was abandoned in place and new piping was installed utilizing schedule 40 piping and fittings.

The licensee has tested the RCIC piping for leaks with no leaking detected to date.

The licensee has implemented a testing procedure to test the RCIC piping on a monthly basis until the mode of failure of the HPCS piping is determined.

The licensee excavated a portion of the piping and removed a sample to determine the mode of failure.

The NRC inspector observed the excavation and inspected the sample of piping removed.

The sample was observed to have a thru wall defect in the weld metal.

Preliminary analysis of the mode of failure appears to be biological corrosion due to sulfide producing bacteria.

The licensee's System Materials Analysis Department (SMAD) is in the process of sectioning the pipe sample for further metallurgical analysis to determine the failure mode.

This itcm remains open pending further analysis and corrective action by the licensee (374/85-029-01).

3.

Open Items Open items are matters which have been discussed with the licensee, which will be reviewed further by the inspector, and which involves some action on the part of the NRC or licensee or both.

An open item disclosed during the inspection is discussed in Paragraph 2.

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4.

Exit Interview l

The inspector met with site representatives (denoted in Persons Contacted i

Paragraph) at the conclusion of the inspection.

The inspector summarized i

the scope and findings of the inspection noted in this report.

The inspector also discussed the likely informational content of the

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inspection report with regard to documents or processes reviewed by the

' inspector during the inspection.

The licensee did not identify any such

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documents / processes as proprietary.

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