ML18106A238

LER 97-010-01:on 970819,CR Operators Initiated Plant Shutdown to Comply W/Requirements of Ts.Caused by Design, Mfg Const/Installation Deficiencies.Calibr Procedure revised.W/980107 Ltr

ML18106A238
Person / Time
Site:	Salem
Issue date:	01/05/1998
From:	Bakken A, Enrique Villar Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-010, LER-97-10, LR-N970806, NUDOCS 9801140146
Download: ML18106A238 (5)

Text

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OPS~G Public Se'rvice Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit JAN 0 7 1998 LR-N970806 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 LER 311/97-010-01 SALEM GENERATING STATION - UNIT 1 and 2 FACILITY OPERATING LICENSE NOS. DPR 70 and DPR 75 DOCKET NOS. 50-272 and 50-311 Gentlemen:

This Licensee Event Report supplement entitled "Technical Specification Required Shutdown - Position Indication Systems" is being submitted pursuant to provide additional information relative to the root cause determination.

Sincerely, A. C. Bakken Ill General Manager -

Salem Operations Attachment EHV/tcp C Distribution LER File 3.7 9801140146 980105 PDR ADOCK 05000311 S PDR Illllll lllll lllll llllll llll lllll llll llll

• 88208.2*

The pmrer is in your hands.

95*2168 REV. 6/94

NRCF~RM366 (4-95)

LIC~NSEE U.S. NUCLEAR REGULATORY COMMISSION EVENT REPORT (LER)

APPROVED BV OMB NO. 3150-0104 EXPIRES 04/30198 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 60.0 HRS.

REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (f-G ~~NUCLEAR (See reverse for required number of REGULATORY COMMISSION, WASHINGTON, DC , *AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) PAOE(3)

SALEM GENERATING STATION UNIT 2 05000311 1 of4 TITLE (4)

TECHNICAL SPECIFICATION REQUIRED SHUTDOWN - POSITION INDICATION SYSTEMS EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER IREVISION NUMBER MONTH DAY YEAR FACILITY NAME Salem Gane~~t~ng Station DOCKET NUMBER 05000272 08 19 97 97 010 - 01 1 5 98 FACILITY NAME DOCKET NUMBER 05000 ATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more) (11)

DE (9) 20.2201(b) 20.2203(a)(2)(v) x 50. 73(a)(2)(i) 50.73(a)(2)(viii)

R 20.2203(a)(1) 20.2203(a)(3)(i) 50. 73(a)(2)(ii) 50. 73( a )(2)(x)

--*--(10) 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50. 73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50. 73(a)(2)(iv) OTHER a.II NAME 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 50.36(c)(1) 50.36(c)(2)

LICENSEE CONTACT FOR THIS LER (12)

50. 73(a)(2)(v)

50. 73(a)(2)(vii)

TELEPHONE NUMBER (Include Area Code)

S~~in Abstract below or in CForm 366A E. H. Villar, Station Licensing Engineer (609) 339-5456 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE ili~ft~il! CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS SUPPLEMENTAL REPORT EXPECTED (14)

Ivesyes, complete EXPECTED SUBMISSION DATE).

(If I x1NO EXPECTED SUBMISSION DATE (15)

MONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On August 18, 1997, during performa.nce of low power reactor physics testing, two analog rod position indicators showed two rods deviating by more than 12 steps from their group demand counter. Technical Specification action statement 3.1.3.2.1 b was entered at 2238 hours0.0259 days <br />0.622 hours <br />0.0037 weeks <br />8.51559e-4 months <br />. On August 19, 1997, at 0005 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> control room operators initiated a plant shutdown to comply with the requirements of the Technical Specifications, and at 0024 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> completed the shutdown by entering (Mode 3) where the Specification is no lonqer applicable.

The apparent cause of this event has been attributed to Deficiencies in Design, Manufacturing Construction/Installation. Contributing factors were inadequate calibration procedural guidance and insufficient management pursuit of technical specification relief.

Corrective action taken was the successful recalibration of the rod position indication system. A long term corrective action taken was the submittal of a license change request to increase the allowable rod deviation to +/- 18 steps (power dependent) . Amendment 183, which approved the license change request, was issued on September 10, 1997.

This condition is being reported in accordance with 10CFRS0.73 (a) (2) (i) . A one hour report was made in accordance with 10CFRS0.72 on August 19, 1997.

NRC FORM 366 (4-95)

NRC PORM 366A

• ' (4-96)

• LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION

• U.S. NUCLEAR REGULATORY COMMISSION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER 6) - .PAGE(S) 2 OF 4 SALEM GENERATING STATION UNIT 2 97 - 010 - 01 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Rod Position Indication System (RPIS) {AA}*

• Energy Industry Identification System (EIIS) codes and component function identifier codes appear in the text as {SS/CCC}.

IDENTIFICATION OF OCCURRENCE Date Determined to be Reportable: August 19, 1997.

CONDITIONS PRIOR TO OCCURRENCE_

Unit 1: Defueled, 0 % Reactor Power Unit 2: Mode 2, 0 % Reactor Power There were no structures, components, or systems that were inoperable at the start of the event that contributed to the event.

DESCRIPTION OF OCCURRENCE On August 18, 1997 during the performance of reactor physics testing for control rod swaps, two control bank D rods were noted to deviate by more than 12 steps from their group demand counter. Technical Specifications 3.1.3.2.1 Action b was entered at 2238 hours0.0259 days <br />0.622 hours <br />0.0037 weeks <br />8.51559e-4 months <br />, following the one hour thermal soak allowed by the Technical Specifications Limiting Condition for Operation.

Technical Specification 3.1.3.2.1 Action b states, in part; "With two or more analog rod position indicators per bank inoperable, within one hour restore the inoperable rod position indicator(s) to OPERABLE status or be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> ... "

As a result of the reactor being operated at approximately 2% Rated Thermal Power, the available neutron flux was not sufficient to perform a flux map to determine the actual position of these rods. Therefore, on August 19, 1997 at 0005 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> control room personnel initiated a reactor shutdown to Hot Standby, in accordance with the applicable Technical Specifications requirements.

The shutdown was completed at 0024 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, when the Unit was placed in a non applicable Mode (Hot Standby) .

NRC FORM 366A (4-95)

NRC FORM 366A (4-95)

• LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION

• U.S. NUCLEAR REGULATORY COMMISSION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE(3) 3 OF 4 SALEM GENERATING STATION UNIT 2 97 - 010 - 01 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

SAFETY SIGNIFICANCE There was no safety significance associated with this event. The control rods were declared inoperable due to a mismatch between their demanded vs.

indicated position .. However, the control rods were always capable of performing their safety function, which is to rapidly insert negative reactivity (fall) into the core following a loss of power.

APPARENT CAUSE OF OCCURRENCE The apparent cause of this event has been attributed to Deficiencies in Design, Manufacturing Construction/Installation.

Rod position is determined by use of a linear voltage transformer consisting of primary and secondary coils alternately stacked on the steel support tube. This method of determining Rod Position Indication has experienced some difficulties with the calibratio"ri technique. Some of the basic problems encountered with calibrating the system are associated with;

1. The instrumentation readout design is based on the assumption that secondary voltage is a linear function of rod position. In fact, the steady-state calibration curve is more of an arc-shaped or even an S-shaped curve such that for some rods the steady-state Zero Span adjustment may not always be able to be calibrated to within the +/- 12 steps, and

2. The instrument response is highly dependent on temperature changes, such as Reactor Coolant System temperature changes and temperature changes associated with rod motion itself. This "transient" thermal response has been categorized as "overshoot," and this transient indication error tends to be worse near the top of the core (rods withdrawn) .

.Additionally, the following contributing causes were determined to be applicable to this event.

The calibration procedure used to calibrate the rods was not adequate. The procedure failed to properly take advantage of the newly implemented plant computer modification .

.Additionally, although a license change request had been developed to provide for a more flexible limiting condition for operation, this option was not proactively pursued prior to the unit restart.

NRC FORM 366A (4-95)

~ (4-95)

NRC FORM 366A

• LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION

• U.S. NUCLEAR REGULATORY COMMISSION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 05000311 YEAR I SErfil'rf:l~AL I~'ir~~ 4 OF 4 SALEM GENERATING STATION UNIT 2 97 - 010 - 01 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PRIOR SIMILAR OCCURRENCES Salem Units 1 and 2 have been shutdown since May and June 1995, respectively.

There are no prior similar occurrences which have been identified within the past two years. However the following LERs have been identified as having been submitted in the past 3 years, prior to .Amendment 166/148 issued May 3, 1995; (1) Associated with docket No. 50-272;94-004, 94-006,94-010, 94-012,94-014, and 95-003, (2) Associated with docket No 50-311;94-001, 94-003,94-009, and 95-002 .

.Amendment 166/148 modified Technical Specification 3.1.3.2.1 Action b, such that the loss of indication of more than one position indicator would not result in an automatic 3.0.3 entry by providing the operators with the same action time under the Limiting Condition for Operation Action Statement.

CORRECTIVE ACTIONS

1. On August 19, 1997, at 0005 hrs a Unit shutdown was initiated in accordance with Technical Specifications 3.1.3.2.1 Action b, and was completed at 0024 hrs. on August 19, 1997.

2. The calibration procedure was revised and the analog rod position indication system was successfully recalibrated.

3. A license change request has been submitted to expand the allowable deviation between demanded and indicated position from +/- 12 steps to +/- 18 steps (power dependent). .Amendment 183, which approved the license change request, was issued on September 10, 1997.

4. Individual rod position scaling has been provided for each rod and has been applied to the position indication provided by the Plant Computer (P-250).

5. Licensing and Operations management meet periodically to discuss license change request priorities.

NRC FORM 366A (4-95)