ML18064A868

LER 95-005-00:on 950721,received Two Inadvertent SISs While Performing TS Test RO-12.Caused by Two Wires Taped Together After Being Removed from Terminal in Attempt to Isolate Sis. Procedure RO-12 Revised

ML18064A868
Person / Time
Site:	Palisades
Issue date:	08/18/1995
From:	Hobe M CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18064A867	List: ML18064A866 ML18064A868
References
LER-95-005-01, LER-95-5-1, NUDOCS 9508250365
Download: ML18064A868 (4)

Text

NRC Form 388 U.S. NUCLEAR REGULATORY COMMISSION 19-831 APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LER)

FACILITY NAME (11 DOCKET NUMBER 121 PAGE 131 Palisades Plant 0 5 0 0 0 2 5 5 OF 0 4 nm 141 LICENSEE EVENT REPORT 95-005 - INADVERTENT ACTUATION OF THE SAFETY INJECTION SYSTEM EVENT DATE 161 LER NUMBER 181 REPORT DATE 181 OTMER FACILITIES INVOLVED 181 REVISION FACILITY NAMES MONTM DAY YEAR YEAR *NUMBER MONTM DAY YEAR N/A 0 6 0 0 0 07219595 0 0 5 00081895 N/A 0 6 0 0 0 TMIS REPORT IS SUBMITTED PURSUANT TO TME REQUIREMENTS OF 10 CFR I: tchedr-ormon oltM followlntlJ (111

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OPERATING MOOE Ill N 20.402Cbl 20.4061cl X 60.73Call21Civl 73.711bl 20.406Cal111al 60.381cll11 60.73Call21M 73.71 lcl 20.406(a)(110il 60.381*112) 60. 7 3(a)l2)Cviil OTMER (Specify in Abatract 20.406Call1 lliiil 60.731*l12Jal 60. 7 3Call211viiilCAI below and in Text, 20.406(a)(110vl 60.73(a)(21flil 60.73(a)(211viiil1Bl NRC Form 388AI 20.406Call1 lM 60.73(a)(211iiil 60.73(all21bd LICENSEE CONTACT FOR TMIS LER 1121 NAME TELEPHONE NUMBER AREA CODE Marjorie A Hobe 6 6 7 6 4 8 9 MANUFAC- REPORTABLE MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT TUR ER TONPROS CAUSE SYSTEM COMPONENT TURER TO NPROS D

J E SUPPLEMENTAL REPORT EXPECTED (14) MONTM DAY YEAR EXPECTED SUBMISSION YES l/f ye., compler. EXPECTED SUBMISSION DA TEI DATE 116)

ABSTRACT Uim/t to 14()() . - : * * . I.e., -ltMr.ly - lin(/#-- trt>>wrlrr.n line*) 1181 On July 21, 1995, at 0141 hrs and 0404 hrs, with the plant shut down for refueling, two inadvertent Safety Injection Signals (SIS) were received while performing Technical Specification Test R0-12, "Containment High Pressure (CHP) and Spray System Test." In both instances, the left channel of safety injection was inadvertently activated. At the time of the event, refueling of the reactor following a full core offload was in progress, with 20% of the reload complete. The Primary Coolant System temperature at the time of the event was approximately 82°F.

The cause of the first SIS was two wires being taped together after removal from a terminal in an attempt to isolate the SIS signal.

The cause of the second SIS was a screwdriver inadvertently touching a terminal on the SIS relay.

All left channel Safety Injection equipment which had not been isolated prior to the event responded as required.

9508250365 950818 PDR ADOCK 05000255 s PDR

• .r:N-::'.RC:-:F:-orm-3'.:':8-:':8A---------------------------U.-S.-NU-CL-EAR-RE-G-ULA-T-OR-Y-CO-M-M-ISSt-O_;,N 19-831 APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /96 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER 121 LER NUMBER 13) PAGE 141 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant o 1o 1s 0 I6 0 I2 OF 0 I4 EVENT DESCRIPTION On July 20, 1995 at 2350 hrs, the Shift Supervisor authorized the start of R0-12, "Containment High Pressure (CHP) and Spray System Test." The purpose of the test is to verify operability of the containment high pressure 2/4 logic by tripping the CHP 2/4 coincidence circuit. The procedure then requires confirmation that 1) the CHP actuated the containment isolation signal, .

2) an initiation signal was sent to the Safety Injection System, and 3) the control room HVAC switched to emergency mode.

As part of the procedure, two wires on terminal 2 of relay TVX-1 [JE;RLY] were removed and taped together to isolate the SIS circuitry. The contact of the two wires off the relay resulted in the first inadvertent Safety Injection Signal at 0141 on the left channel test of the CHP. As required when receiving a safety injection signal, the charging pump (P-55C), boric acid pump (P-568) and component cooling pump (P-52C) started. The 2400 volt Bus 1E was deenergized upon receiving the SIS. Service water pump (P-78) was already in service. No safety injection occurred. The High Pressure System Injection (HPSI) pumps were disabled; the Low Pressure System Injection (LPSI) pumps were lined up for shutdown cooling. The charging pumps received a start signal and did inject borated water into the PCS with a boric acid concentration equal to or greater than that required for refueling. This is normal operation of the charging pumps and the pumps are not considered part of the Safety Injection System.

At 0142, the Reactor Operator stopped the charging pump (P-55C) and boric acid pump (P-568);

LPSI was throttled. At 0158, component cooling pump (P-52C) was stopped. The left channel of the CHP was reset at 0159 and SIS was reset at 0202. The 2400 volt Bus 1 E was re-energized at 0211 . Checklists for restoration of safety injection and containment isolation equipment were completed by 0230.

The second inadvertent SIS occurred while restoration of the plant from R0-12 was in progress.

While relanding wires removed during the R0-12 test, the electrician landed a single wire on terminal 13 of relay SIS-7 [JE;RL Y]. During the process, the retractable portion of the screwdriver being used by the electrician to connect the wire came in contact with the next terminal . This completed a circuit and, at 0404, caused the second SIS.

Upon receiving the second SIS, charging pump (P-55C), boric acid pump (P-56B), and component cooling pump (P-52C) again started. These pumps were stopped at 0405. Service water pump (P-78) was in service. No safety injection occurred. The boric acid tank gravity feed motor operated valves again opened and were closed at 0405. Bus 1 E had deenergized and was reenergized at 0419. Safety injection and containment isolation checklists were completed at 0420 to restore the systems.

NRC Form 388A U.S. NUCLEAR REGULATORY COMMISSION

- (9-83) APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) _ DOCKET NUMBER 121 LER NUMBER 131 PAGE (4)

SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant o Io 1s 0 I6 0 I3 OF 0 I4 SAFETY SIGNIFICANCE All operator actions for both inadvertent SIS actuations were in accordance with procedures, with no safety-significant deviations or abnormalities. The plant was in a refueling outage and these events did not have an adverse impact on the operational safety of the plant or upon the safety of plant personnel or the general public.

CAUSE OF THE EVENT The first inadvertent SIS was due to two wires being taped together after removal from a terminal due to an unclear procedure.

The cause of the second inadvertent SIS was a screwdriver accidentally shorting adjacent terminals of an SIS relay.

CORRECTIVE ACTIONS

1. R0-12 was revised on July 22, 1995 to specify that the two wires removed from terminal 2 on relay TVX-L were to be isolated and insulated from each other when they are lifted during the test. This was also done for the right channel portion of the test. Caution statements were added to the. procedure regarding the tight work space of electrical connections suggesting that temporary insulation may be necessary.

2. The Training Department will provide a case study on test-related problems and successes which occurred during the 1995 Refueling Outage for Engineering, Operations, and Maintenance.

EVENT ANALYSIS Procedure R0-12 had recently been revised and this was the first time the revised procedure had been utilized. The revision made significant changes to the test. These included disconnecting the safety injection signal circuitry from the CHP signal. The change eliminated the operation of numerous pieces of safeguards equipment including HPSI, LPSI, service water, component cooling water, boric acid and charging pumps and all associated valves. The change also eliminated a significant power interruption to the site by not deenergizing 2400 volt Bus 1 E.

The inadvertent SIS occurred when two lifted wires were taped together because of inadequate procedural guidance. Specifically, R0-12 did not indicate that the two wires removed from terminal 2 of relay TVX-L were to be insulated and isolated from each other. The procedure sponsor assumed the insulation and isolation of removed wires to be standard electrical maintenance practice. Standard electrical maintenance practice is to maintain removed wires as they had been on the terminal unless otherwise directed by work instructions.

.e NRC Form 38SA U.S. NUCLEAR REGULATORY COMMISSION

~ (9*83J APPROVED OMB NO. 3160-0104 EXPIRES: B/31186 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 111 _ DOCKET NUMBER 121 LER NUMBER 131 PAGE 141 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant o Io 16 0 I6 0 I4 OF 0 I4 There were a number of missed opportunities to correct the misunderstanding. The procedure sponsor held no direct discussions with the electrician who performed the procedure review. No procedure validation was performed. Engineering representation was not present at either the pre-job briefing or during the test.

The root cause of the first inadvertent SIS was inadequate communication between the procedure sponsor (System Engineer) and Electrical Maintenance. This was the first time that the revised procedure had been used and the first time Electrical Maintenance was to participate in the test.

Missed opportunities to establish communication occurred during the procedure revision process, at the pre-job briefing and during the conduct of the test.

The root cause of the second inadvertent SIS was insufficient work space due to the plant configuration. The terminals are iri a tight configuration where the wire was to be landed. The SIS occurred even though an extra precaution was taken by taping the nearby terminal.

PREVIOUS EVENTS There have been three inadvertent SIS actuations since 1990 due to the performance of inadequate procedures or work instructions [LER 90-019, 11 /01 /90; LER 91-005, 01 /25/91; LER 92-032, 04/06/92). Corrective actions in these events were to revise the procedure and conduct limited training to the work group directly involved with the event.