ML13260A082

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LER 13-002-00 for James A. FitzPatrick, for RCIC Condensate Storage Tank Level Switch Inoperable Due to Corrosion
ML13260A082
Person / Time
Site: FitzPatrick Constellation icon.png
Issue date: 09/16/2013
From: Lawrence Coyle
Entergy Nuclear Northeast, Entergy Nuclear Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
JAFP-13-0125 LER 13-002-00
Download: ML13260A082 (5)
v • d • e


Text

JAFP-13-0125 September 16, 2013 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Entergy Nuclear Northeast Entergy Nuclear Operations, Inc. James A. Fitzpatrick NPP P.O. Box 110 Lycoming, NY 13093 Tel 315-349-6024 Fax 315-349-6480 Lawrence M. Coyle Site Vice President

-JAF

Subject:

LER: 2013-002, RCIC Condensate Storage Tank Level Switch Inoperable due to Corrosion

Dear Sir or Madam:

James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 License No. DPR-59 This report is submitted in accordance with 10 CFR 50.73(a}(2)(i)(B),

An Operation or Condition Prohibited by Technical Specifications.

There are no commitments contained in this report. Questions concerning this report may be addressed to Mr. Chris M. Adner, Licensing

Manager, at (315) 349-6766.

L?"C. Lawrence M. Coyle Site Vice President LMC/CMA/mh Enclosure(s):

JAF LER 2013-002, RCIC Condensate Storage Tank Level Switch Inoperable due to Corrosion cc: USNRC, Region 1 USNRC, Project Directorate USNRC, Resident Inspector INPO Records Center (ICES)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. 1. FACILITY NAME James A. FitzPatrick Nuclear Power Plant 2. DOCKET NUMBER 05000333 3. PAGE 1 OF 4 4. TITLE RCIC Condensate Storage Tank Level Switch Inoperable due to Corrosion 5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REVNO MONTHDAY YEAR FACILITY NAME N/A DOCKET NUMBERN/A 08 19 13 2013 - 002 - 00 09 16 13 FACILITY NAME N/A DOCKET NUMBER N/A 9. OPERATING MODE 1 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A)

X 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(ix)(A) 50.73(a)(2)(x) 73.71(a)(4) 73.71(a)(5)

OTHER Specify in Abstract below or in NRC Form 366A 10. POWER LEVEL 100 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME Mr. Chris M. Adner, Licensing Manager TELEPHONE NUMBER (Include Area Code)

(315) 349-6766 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT MANU- FACTURER REPORTABLETO EPIX CAUSE SYSTEM COMPONENT MANU- FACTURER REPORTABLETO EPIX C EJ LS R290 Y ___ ___ ___ ___ ___ 14. SUPPLEMENTAL REPORT EXPECTED 15. EXPECTED SUBMISSION DATE MONTH DAY YEAR Yes (If yes, complete 15. EXPECTED SUBMISSION DATE) X NO __ __ ____

ABSTRACT (Limit to 1400 spaces, i.e., approximat ely 15 single-spaced typewritten lines) The Reactor Core Isolation Cooling (RCIC) "B" condensate storage tank (CST) level switches failed to trip due to corrosion build-up caused by water intrusion. The first instance in which corrosion interfered with the trip mechanism was when 13LS-76B failed to trip due to corrosion while testing on July 16, 2013. The second instance was both 13LS-76B and 13LS-77B failed to trip due to corrosion on August 19, 2013. These two instruments are 2 of 4 channels for the CST low level function of the RCIC system. The "A" side channels are Operable and show no signs of being affected by corrosion or water intrusion. The "B" side channels share a junction box which is evidently the source of water intrusion from environmental conditions of the CST pit. This deficiency is being corrected by replacing the affected level switches and update testing procedures to identify signs of corrosion. The Technical Specifications (TS) requires all 4 RCIC CST level switches be Operable. Since two of the level switches were Inoperable due to corrosion the RCIC system also became Inoperable. Since the actions prescribed by the TS were not performed, the RCIC had been in a condition prohibited by TS, 10 CFR 50.73(a)(2)(i)(B).

NRC FORM 366 (10-2010

)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET

1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGEJames A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0. 2 OF 4 2013 - 002 - 00 NRC FORM 366A (10-2010)

NARRATIVE Background Reactor Core Isolation Cooling (RCIC) System [BN] is comprised of various components which include pumps, valves, piping, and instrumentation. The RCIC System is designed to operate either automatically or manually following reactor pressure vessel isolation accompanied by a loss of coolant flow from the feedwater system to provide adequate core cooling and control the reactor water level under these conditions. The normal water source for the RCIC is the Condensate Storage Tanks (CST) [KA] 33TK-12A and 33TK-12B.

Low CST Level indicates the unavailability of an adequate supply of makeup water from this normal source (CST). Normally, the suction valve between the RCIC pump and the CSTs is open and, upon receiving a RCIC initiation signal, water for RCIC injection would be taken from the CSTs. However, if the water level in both CSTs falls below a preselected level, the water source is automatically changed to the suppression pool. This ensures that an adequate supply of makeup water is available to the RCIC pump. Level switches detect the water level for the 2 CSTs. Each tank has 2 RCIC instrumentation level switches, 13LS-76A and 13LS-77A for the "A" tank and 13LS-76B or 13LS-77B for the "B" Tank. Four channels of low CST level function are available and are required to be Operable when RCIC is required to be Operable to ensure that no single instrument failure can preclude RCIC automatic suction source alignment to suppression pool source. Preceding events On 01-04-2013, 13LS-77B did not actuate (trip) on low CST water level during ISP-75-1. The other three level switches operated satisfactory. The 13LS-77B was then re-tested and operated satisfactory. The switch was disassembled and water was found in the switch casing. The Apparent Cause for the source of the water was from the environmental conditions in the CST pit. Water penetrated through the junction box (JB-CIC-31) into a conduit to the level switch assembly. The junction box has weep holes to drain water; however, it was evident that there was a buildup of water in the junction box due to foreign material blocking the weep hole. The weep hole was cleaned and the contacts in the level switch were replaced. The excessive water in the switch affected the switch operation by causing intermittent failure.

On 03-28-2013, ISP-75-1 was performed successfully for all 4 RCIC CST level switches. EVENT DESCRIPTION On 07-16-2013, 13LS-76B did not trip on low CST water level during ISP-75-1. The other three level switches actuated (tripped) properly. When the top cover was removed the technician stated that it took excessive force to manually actuate the switch. Once the switch was freed up it worked repeatedly. There was evidence of corrosion due to water intrusion into the electrical top works and that the water was apparently coming from within the upstream conduit and junction box; however, water was not present.

On 08-19-2013, 13LS-76B and 13LS-77B did not trip on low CST water level during ISP-75-1. The plant was at 100% power. Corrosion formation due to water exposure prevented the switch from changing state. The other two "A" CST level switches operated satisfactory. EVENT ANALYSIS The failures of 13LS-77B and 13LS-76B both stem from water intrusion into the switch casing from their shared junction box (JB-CIC-31) and associated conduit. The junction box and level switches are not Environmentally Qualified devices. Rain water or run off water from conditions in the CST pit were able to penetrate the junction box and make its way through the conduit to the level switch assembly. Only one of two level switches (13LS-76B or 13LS-77B) for "B" CST and one of the two level switches (13LS-76A or 13LS-77A) for "A" CST are required to perform the swap from the CST to the suppression pool. This condition only affects the "B" CST level NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET

1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGEJames A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0. 3 OF 4 2013 - 002 - 00 NRC FORM 366A (10-2010) switches. In January, water present in the switch directly caused the failure of 13LS-77B. There is no firm evidence that the level switches continued to be Inoperable as a result of excessive water after the January event. On March 28, 2013, ISP-75-1 was performed successfully for all RCIC CST level switches. Later, in July and August, both "B" CST level switches (13LS-76B and 13LS-77B) experienced corrosion on the trip mechanism from water exposure. Whenever a level switch was tested and did not trip repairs were performed and the level switch was restored to Operable status prior to exiting the maintenance activity. However, as a consequence of corrosion, the "B" CST level switches were Inoperable from July 16, 2013, until restoring the level switches to Operable status after the event of August 19, 2013. RCIC Instrumentation Limiting Condition of Operation (LCO) 3.3.5.2 requires that the RCIC System instrumentation for each 4 channels of Low CST water level be Operable while in Mode 1, Mode 2, and Mode 3 with reactor steam dome pressure > 150 psig. When the channel was inoperable, Condition D action required that the channel be placed in trip. When this condition was not met Condition E required that RCIC be declared inoperable. LCO 3.5.3 required RCIC be restored to Operable within 14 days or be in Mode 3.

Since both level switches 13LS-76B and 13LS-77B were Inoperable between July 16, 2013 and August 19, 2013. This period of time is longer than allowed by the Technical Specifications (TS); therefore, JAF had a condition reportable per 10 CFR 50.73(a)(2)(i)(B) as prohibited by TS. High Pressure Coolant Injection (HPCI) Operability [BJ] LCO 3.5.1 Condition C states that if HPCI is Inoperable then verify RCIC is Operable administratively. When RCIC is concurrently Inoperable then Condition G requires the plant to be in Mode 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The history of HPCI Operability was verified since January 1, 2013. All Inoperable instances were associated with the performance of normal surveillance procedures. At no point was HPCI Inoperable for greater than 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Therefore, this condition was not prohibited by TS 3.5.1 or the corresponding RCIC TS 3.5.3 Condition B. CAUSE OF EVENT The Apparent Cause of the failure of Reactor Core Isolation Cooling (RCIC) instrumentation for the "B" Condensate Storage Tank (CST) level switches was corrosion initiated by water intrusion. The source of the water into the level switches assembly came from junction box JB-CIC-31 shared by the level switches (13LS-76B and 13LS-77B).

EXTENT OF CONDITION The only susceptible level switches to this condition were those associated with the "B" CST (13LS-76B and 13LS-77B) due to a shared junction box. There is no evidence that supports that either the "A" CST level switches 13LS-76A or 13LS-77A were inoperable or that the corresponding HPCI level switches 23LS-74A, 23LS-75A, 23LS-74B, 23LS-75B were inoperable.

FAILED COMPONENT IDENTIFICATION: Manufacturer: Robertshaw Controls Manufacturer Model Number: SL301-A2XS11-C31-1 NPRDS Manufacturer Code: R290 NPRDS Component Code: LS FitzPatrick Component ID: 13LS-76B and 13LS-77B

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET

1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGEJames A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0. 4 OF 4 2013 - 002 - 00 NRC FORM 366A (10-2010) CORRECTIVE ACTIONS Completed Actions Replaced affected components of 13LS-77B on 1/10/13 Opened junction box JB-CIC-31 and cleared obstruction on 1/10/13 Temporarily increased ISP-75-1 frequency to 45 days. Revise ISP-75-1 and ISP-75 to inspect and verify satisfactory condition of the junction box, switches, and corresponding conduit during the quarterly surveillance tests.

Post 8-19-13 13LS-76B placed in trip 13LS-77B corroded components replaced and level switch returned to Operable status Future Actions Replace 13LS-76B in its entirety Examine the extent of the Corrosion Condition in the "A" CST level switches and the four corresponding HPCI level switches. Evaluate and implement a method to prevent of reduce water intrusion into HPCI and RCIC CST level switches. SAFETY SIGNIFICANCE Nuclear Safety There were no actual nuclear safety consequences during this period as a result of this event. The potential consequence was that the RCIC system may not have operated as designed. If RCIC was called upon to Operate during an accident scenario and the CSTs ran low on water then RCIC may not have detected this condition and swapped to the alternate water source automatically. Since this condition only affects 2 of 4 channels of RCIC low level CST instrumentation, in order to prevent the required function of the low level CST function both 13LS-76B and 13LS-77B need to fail to trip concurrently. Also, Operators have the ability to manually perform this swap. JAF accident analysis does not take credit for the operation of the RCIC system. The accident analysis assumes the operation of the HPCI system and operation of the Automatic Depressurization System in conjunction with the Low Pressure Coolant Injection System. These systems were unaffected by the identified condition. Therefore, the potential consequences of the RCIC system inoperable during this period were minimal. Radiological Safety No radiological impact or dose associated with this condition. Industrial Safety No safety events or abnormal increases to personnel risk. SIMILAR EVENTS There are no historical cases of RCIC or HPCI level switches not functioning as a result of corrosion at JAF. REFERENCES January 4, 2013 - CR-JAF-2013-00061 July 16, 2013 - CR-JAF-2013-03735 August 19, 2013 - CR-JAF-2013-04311, CR-JAF-2013-04312 JAF Technical Specifications and Bases, 3.3.5.2, "Reactor Core Isolation Cooling (RCIC) System Instrumentation" ISP-75-1, RCIC CST Low Water Level Switch Functional Test

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