IR 05000413/1999010

Insp Repts 50-413/99-10 & 50-414/99-10 on 990314-0424. Violation Being Considered for Escalated Enforcement Action Noted.Major Areas Inspected:Operations

ML20206U416
Person / Time
Site:	Catawba
Issue date:	05/10/1999
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20206U413	List: ML20206U409 ML20206U416
References
50-413-99-10, 50-414-99-10, NUDOCS 9905250204
Download: ML20206U416 (7)

Text

\

.

. . .

U.S. NUCLEAR REGULATORY COMMISSION

REGION II

Docket Nos: 50-413, 50-414 License Nos: NPF-35, NPF-52

.

Report Nos.: 50-413/99-10,50-414/99-10 Licensee: Duke Energy Corporation System: Catawba Nuclear Station, Units 1 and 2 Location: 422 South Church Street Charlotte, NC 28242 Dates: March 14 through April 24,1999 Inspectors: D. Roberts, Senior Resident inspector R. Franovich, Resident inspector Approved by: C. Ogle, Chief Reactor Projects Branch 1 Division of Reactor Projects

.

Enclosure

'

9905250204 990510 PDR ADOCK 05000413 G PDR

.

.-.

EXECUTIVE SUMMARY Catawba Nuclear Station, Units 1 and 2 NRC Inspection Report 50-413/99-10,50-414/99-10 This specialinspection focused on the integrated efforts of the Catawba Nuclear Station staff to evaluate, determine the root cause of, and correct a licensee-identified configuration control problem affecting the Standby Shutdown System from December 16 through 29,1998. The report covers the resident inspection period from March 14 to April 24,1999. [ Applicable template codes and the assessment for items inspected are provided below.)

Operations

-

An apparent violation of previous Technical Specification 3.7.13 [now Selected Licensee Commitment item 16.7-9 (Standby Shutdown System)] was identified concerning two mispositioned electrical circuit breakers that rendered the Standby Shutdown System inoperable from December 16 through 29,1998. This issue affected both Catawba unit (Section 02.1; [1 A - eel])

-

Upon discovery of the mispositioned breakers, licensee personnel promptly restored the Standby Shutdown System to operable status and made appropriate notifications to the NRC in the time period required. (Section O2.1; [1 A, 5A - POS])

-

The licensee's procedures for operating the Standby Shutdown System during certain flood, power, fire, and security events were adequate to maintain equipment protection and perform their intended functions. Only minor enhancements were neede Licensee personnel interviewed were knowledgeable of these procedures and how to implement them. (Section O3.1; [1C,38 - POS))

-

The licensee's root cause evaluation provided in Licensee Event Report (LER) i 50-413/98-19 sufficiently developed human performance issues that resulted in the j mispositioned Standby Shutdown System breakers. The licensee adequately addressed possible contributing factors in its corrective action program. (Section 08.1; [5B - POS])

I

.

-

!

.

.c Report Details Summary of Plant Status During the period of this event (December 16 through 29,1998) both units were at approximately 100 percent reactor powe . Operations 02 Operational Status of Facilities and Equipment O2.1 Standby Shutdown SystemlSSS) Inocerable Due to Personnel Error Durina Eauipment Restoration Process Inspection Scope (71707)

The inspectors reviewed the circumstances associated with LER 50413/98-19 (previously discussed in inspection Report 50-413,414/98-12), in which the SSS was determined to be inoperable for nearly two weeks because two circuit breakers in a SSS motor control center were misaligned. The inspectors discussed this issue with plant personnel, reviewed SSS operating and test procedures, reviewed the restoration procedure associated with SSS maintenance activities on December 16,1998, and reviewed the licensee's immediate corrective actions for restoring system operabilit Observations and Findinas On December 29,1998, the licensee discovered that two breakers associated with the SSS were open when they should have been closed. The breakers were F02C, Motor Control Center 1EMXS Attemate Supply, and R03D, Motor Control Center 2EMXS Alternate Supply. With the two breakers open, the SSS was inoperable for Units 1 and 2. The licensee determined that the two breakers had been in the incorrect position for 13 days, which exceeded the allowed outage time of seven days before action to initiate a unit shutdown to Mode 3 (hot standby) was required within the following six hour SSS Backaround information The SSS is a non-safety-related system that is used to cope with certain flood, power, fire, and security events in order to achieve and maintain hot standby condition for one or both units. The SSS is utilized for certain events that may result in the loss of normal reactor coolant pump (RCP) seal injection. This involves a time-critical task to provide sealinjection with the associated unit's standby makeup pump (which can be powered from 1SLXG using the SSS diesel) within 10 minutes in order to maintain RCP seal integrity. Some of the SSS loads are supplied from 1(2)EMXS, which is normally aligned to the A train 4160 volt alternating current (VAC) vital electrical bus. Procedure OP/0/B/6100/013, Standby Shutdown System Operations, Revision 41, directs operators to open breaker 1(2) F01 A associated with 1(2)EMXA, which is powered from 1(2) ETA (the A train 4160 VAC vital bus), and close breaker 1(2)F03A associated with 1SLXG, the auxiliary power supply, during postulated events. If power to 1SLXG is lost, the SSS diesel engine will be manually started to power the SSS loads, assuming the required breaker alignment is in place. The standby makeup pump suction and discharge isolation valves are powered from 1(2)EMXS. These valves are normally closed and would not be capable of opening and providing RCP sealinjection with breakers F02C and R03D open since they are in series with breaker 1(2)F03A, respectivel .,

To ensure that the time-critical task of providing RCP seal injection can be performed within 10 minutes, the licensee has procedurally minimized the number of breakers that need to be manipulated (only F01 A and F03A) to transfer power to 1SLXG. With no procedural steps provided to verify that the third breaker (F02C for Unit 1 and R03D for Unit 2) was closed, the ability to provide reactor coolant pump seal injection within 10 l minutes could not be ensure Personnel Error Durino Eouioment Restoration Procedure Devetooment The licensee determined that breakers F02C and R03D had been left in the open position following preventive maintenance on December 16,1998. The normally closed breakers were tagged and placed in the OFF (open) position in support of the maintenance. Following completion of the maintenance activities, the tags were removed from the breakers, but the breakers were left in the OFF position in accordance with the system restoration procedure, Tag-Out 08-2811. The system restoration procedure incorrectly specified that the breakers be restored in the open position. The licensee determined that a senior reactor operator (SRO) who generated the restoration procedure assumed that, since the breaker was associated with an alternate power supply, then the normal position of the breaker was OFF. This SRO failed to reference applicable procedures to verify the normal breaker position. A second SRO reviewed and approved the tag-out procedure and missed the error. The misaligned breakers were identified and questioned by another operator on December 29,1998, who was performing an unrelated procedure validation walk-throug Operation Management Procedure (OMP) 2-18, Tagout Removal and Restoration Procedure, Revision 50, Step 6.2, Restoration / Partial Restore Record Sheet, item AA, states that equipment is to be normally returned to the position specified by a governing operating procedure checklist, the body of a goveming procedure, or as specified by the approving SRO based on plant conditions. The i.ispectors determined that the governing operating checklists for the two SSS breakers were not reviewed when the operators determined the required restored positions. Discussions with licensee personnel and review of assot nd Problem Investigation Process report (PIP)

O-C98-4935, revealed that othen possible contributing factors included the fact that the restoration procedure did not reference OP/1/A/6350/001, Normal Power Checklist, which specifies the normal operating positions of the breakers; and station drawings did not accurately depict the breakers' normal operating positions. The inspectors concluded that these contributors did not cause the human performance error when the clearance restoration procedure was being developed and approved by the SROs in support of the December 16,1998, maintenance activities. These items were, however, properly included in the licensee's corrective action progra Root Cause Determination The licensee determined that the root cause for this event was inadequate work practices. Operations personnel failed to follow the established practice of reviewing OP/1/A/6350/001, Normal Power Checklist, to determine the correct normal (restored)

position of breakers F02C and R03D. Based on the breakers' labels, operations personnel wrongly assumed that the normal position of the breakers was open. The inspectors concluded that the licensee's root cause determination, as well as its development of possible contributing factors in the corrective action program, was

_ .

.

.

comprehensive. Several short- and long-term corrective actions were specified to restore operability and prevent recurrence. These included specifying, in the equipment data base and locally at the breakers, that having them in the OFF (open) position would render the SSS inoperable. Other actions were taken to address the human performance issue Safety Sianificance

.

The SSS is not considered safety-related. However, the SSS provides an alternate and independent means for maintaining the plant in a safe shutdown (for the SSS this is Hot .

Standby [ Mode 3]) condition following certain loss of power, flooding, fire, and security events that result in the loss of normal RCP seal injection. These events are not ,

assumed to be concurrent with a design basis accident. Safe shutdown is achieved when: (1) the reactor is prevented from achieving criticality; and (2) adequate heat sink is provided to ensure reactor coolant system pressure and temperature design and safety limits are not exceeded. Upon a loss of normal RCP sealinjection, the SSS is placed in service and the associated unit's standby makeup pump is started to provide seal injection. This is to be accomplished within 10 minutes to ensure that significant RCP seal damage and a resultant small break loss of coolant accident do not occu With breakers F02C and R03D in the wrong positions and not referenced in the SSS operating procedure, the SSS's ability to perform its intended safety function of maintaining RCP seal integrity could not be ensure Reculatory Sianificance The inspectors concluded that the SSS was inoperable from December 16 through 29, 1998, without appropriate actions being taken to restore operability within seven days or perform a plant shutdown within the following six hours as required by Technical Specifications (TS). [As of January 16,1999, following the licensee's conversion to improved TS, this requirement was transferred to the Selected Licensee Commitments (SLC) document (item 16.7-9), considered Chapter 16 of the Catawba Updated Final Safety Analysis Report.) The licensee's failure to restore SSS operabiity or perform a plant shutdown within allowed outage times is considered an apparent violation of previous TS 3.7.13. This is identified as apparent violation (eel) 50-413,414/99-10-01:

Standby Shutdown System Inoperable in Excess of TS Limits Due to Mispositioned Circuit Breaker c. Conclusions An apparent violation of previous Technical Specification 3.7.13 [now Selected Licensee Commitment item 16.7-9 (Standby Shutdown System)) was identified concerning two mispositioned electrical circuit breakers that rendered the Standby Shutdown System inoperable from December 16 through 29,1998. This issue affected both Catawba unit Upon discovery of the mispositioned breakers, licensee personnel promptly restored the Standby Shutdown System to operable status and made appropriate notifications to the NRC in the time period require j J

.

..

>

03 Operations Procedures and Documentation O3.1 SSS Operatina Procedures and Plant Staff Knowledae - General Comments (71707)

The inspectors reviewed procedures associated with the operation of the SSS for loss of nuclear service water, loss of component cooling water, and station blackout events (i.e., events resulting in loss of normal RCP seal injection), and interviewed operations and security personnel responsible for implementation. One minor discrepancy was identified in OP/0/B/6100/013, Standby Shutdown System Operations, Revision 4 Procedural steps goveming the transfer to the SSS referenced a wrong structural

' column identification number in describing a critical terminal box location. This item was communicated to station personnel for correctio Otherwise, the licensee's procedures for operating the SSS during certain flood, power,

. fire, and security events were adequate to maintain equipment protection and perform their intended functions. Licensee personnel interviewed were knowledgeable of these procedures and how to implement the Miscellaneous Operations issues (40500, 92901)

- 08.1 - (Closed) LER 50-413/98-19-00: Standby Shutdown System inoperable in Excess of Technical Specification Allowed Outage Time due to Mispositioned Breakers Caused by Personnel Error The licensee's root cause evaluation provided in this LER sufficiently developed human -

performance issues that resulted in the mispositioned breakers. The licensee adequately addressed possible contributing factors in its corrective action progra Based on the inspectors' review of the subject event, as described in Sections 02 and

' 03 of this inspection report, this LER is close V. Management Meetmgs X1 Exit Meeting Summary The inspector presented the inspection results to members of licensee management at the conclusion of the inspection on May 3,1999. The licensee acknowledged the findings presented. No proprietary information was identife .

e

- . - - - - - - - - - -

,.-

.

..c

PARTIAL LIST OF PERSONS CONTACTED Licensee R. Beagles, Safety Assurance Manager M. Boyle, Radiation Protection Manager S. Bradshaw, Safety Assurance Manager G. Gilbert, Regulatory Compliance Manager *

R. Glover, Operations Superintendent P. Herran, Engineering Manager R. Jones, Station Manager G. Peterson, Catawba Site Vice-President F. Smith, Chemistry Manager R. Parker, Maintenance Manager INSPECTION PROCEDURES USED IP 40500: Effectiveness of Licensee Controls in identifying, Resolving, and Preventing Problems IP 71707: Plant Operations IP 92901: Followup - Operations ITEMS OPENED, CLOSED, AND DISCUSSED Opened 50-413,414/99-10-01 eel Standby Shutdown System inoperable in Excess of TS Liro;ts Due to Mispositioned Circuit Breakers (Secuon O2.1)

Qloped 50-413/98-19-00 LER Standby Shutdown System inoperable in Excess of Technical Specification Allowed Outage Time due to Mispositioned Breakers Caused by Personnel Error (Section 08.1)

LIST OF ACRONYMS USED CFR - - Code of Federal Regulations eel -

Escalated Enforcement item (Apparent Violation)

LER -

Licensee Event Report NRC -

Nuclear Regulatory Commission PIP - Problem Investigation Process RCP -

Reactor Coolant Pump SLC -

Selected Licensee Commitments SRO -

Senior Reactor Operator SSS -

Standby Shutdown System TS- -

Technical Specification ,

VAC - Volts Attemating Current

]

!

j