05000305/LER-2005-001, Re Reactor Thermal Power Eight-Hour Average Limit Exceeded

Re Reactor Thermal Power Eight-Hour Average Limit Exceeded

ML050970304
Person / Time
Site:	Kewaunee
Issue date:	04/01/2005
From:	Lambert C Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-05-037 LER 05-001-00
Download: ML050970304 (6)

LER-2005-001, Re Reactor Thermal Power Eight-Hour Average Limit Exceeded

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(B)
3052005001R00 - NRC Website

text

Ctu Committed to NuclearxcO Kewaunee Nuclear Power Plant Operated by Nuclear Management Company, LLC April 1, 2005 NRC-05-037 10 CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Kewaunee Nuclear Power Plant Docket 50-305 License No. DPR-43 Reportable Occurrence 2005-001-00 In accordance with the requirements of 10 CFR 50.73, "Licensee Event Report System," the attached Licensee Event Report (LER) for reportable occurrence 2005-001-00 is being submitted.

This letter contains no new commitments and no revisions to existing commitments.

Craig W.

ert Site Vice-President, Kewaunee Nuclear Power Plant Nuclear Management Company, LLC Enclosure (1) cc:

Administrator, Region ll, USNRC Senior Resident Inspector, Kewaunee, USNRC INPO Records Center N490 Highway 42

• Kewaunee, Wisconsin 54216-9511 Telephone: 920.388.2560

ENCLOSURE1 LICENSEE EVENT REPORT (LER) 2005-001-00 4 pages follow

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 6-30-2007 (6-2004)

Estimated burden per response to comply with this mandatory collection request 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />.

Reported lessons learned are incorporated Into the licensing process and fed back to Industry.

LICENSEEEVENTREPORT(LER)

Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch R(T5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or byintemet e-(See reverse for required number of mail to Infocollects~nrc.gov, and to the Desk Officer, Office of Information and Regulatory

(

eAffairs, NEOB-1 0202,(3150-0066), Office of Management and Budget Washington, DC 20503.

digits/characters for each block)

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.

FACILITY NAME (1)

DOCKET NUMBER (2)

PAGE (3)

Kewaunee Nuclear Power Plant 05000305 1 of 4

TITLE (4)

Reactor Thermal Power Eight-Hour Average Limit Exceeded EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILIIES INVOLVED (8)

SECUENTIAL REV FACILIY NAME DOCKET NUMBER MO l

DAY YEAR YER NUMBER NO MO DAY YEAR FACILITY NAME DOCKET NUMBER 01 31 2005 2005 001 -

00 04 01 2005 OPERATING N

THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR.: (Check all that apply) (11)

MODE (9) 202201(b) 20.2203(a)(3)(i0) 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)

POWER 100

_20.2201(d)

_ 202203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LEVEL (10) 1 20.2203(a)(1) 50.36(c)(1)(i)(A) 50.73(a)(2)(iv)(A) 73.71 (a)(4)

_ 20.2203(a)(2)(i)

_ 50.36(c)(1)(ii)(A)

_ 50.73(a)(2)(v)(A)

_ 73.71 (a)(5) 20.2203(a)(2)(ii)

_ 50.36(c)(2) 50.73(a)(2)(v)(B)

OTHER 20.2203(a)(2)(iii) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C)

Specify In Abstract below or In

- =

20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 20.2203(a)(2)(v)

X 50.73(a)(2)(i)(B) 50.73(a)(2)(vii):A) 20.2203(a)(3)(i) 50.73(a)(2)(i)(A) 50.73(a)(2)(viii)(B)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

Robert Reynnells j

(920) 388-8791 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13)

MANU-I REPORTABLE MANU-REPORTABLE

CAUSE

SYSTEM COMPONENT FACTURER TO EPIX

CAUSE

SYSTEM COMPONENT FA CTURER TO EPIX SUPPLEMENTAL REPORT EXPECTED (14)

EXPECTED MONTH DAY YEAR X I YES (If yes, complete EXPECTED SUBMISSION DATE).

NO DATE (15) l 05 13 2005 ABSTRACT On January 31, 2005, Kewaunee Nuclear Power Plant was in operation at 100 percent power. Instrument and Control (I&C) personnel were performing two surveillance test activities -- Surveillance Procedure (SP) 47-316A (Channel 1 (Red) Instrument Channel Test) and SP 05A-34C-1 (Feedwater Flow Transmitter Channel 1 (Red)

Calibration). At approximately 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />, these surveillances caused the reactor thermal power 1 -minute, 15-minute, and 8-hour average indications to become inaccurate. The Control Room operators entered procedure A-CP-46 (Abnormal Plant Process Computer System) to determine appropriate actions. The Alternate Reactor Thermal Output (ARTO) system was being used to monitor reactor power. At approximately 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, the 1-minute thermal power readings returned to approximately 1772 megawatts thermal (MWth), 100 percent power.

Procedure A-CP-46 was exited at approximately 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, and use of ARTO was stopped. At the time the 8-hour Reactor Thermal Output (RTO) average was viewed as not valid. During shift tumover there was no direction given concerning the expected affect on the 8-hour average. At 1952 hours0.0226 days <br />0.542 hours <br />0.00323 weeks <br />7.42736e-4 months <br />, the shift performed an 11 gallon dilution to compensate for normal core bum up. At both 2047 hours0.0237 days <br />0.569 hours <br />0.00338 weeks <br />7.788835e-4 months <br /> and at 2057 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.826885e-4 months <br />, the RTO 15-minute average PPCS alarm came in at 1773 MWth. This computer annunciator cleared within minutes. As the effects of the earlier l&C surveillances were being dropped from the 8-hour average calculation, indicated 8-hour average power started to increase, resulting in a high power alarm at 2131 hrs. Indicated 8-hour average reactor power peaked at 1772.07 MWth. A 3.4 gallon boration was performed at 2141 hours0.0248 days <br />0.595 hours <br />0.00354 weeks <br />8.146505e-4 months <br />, and power reduced to less than 1772 MWth at 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br />. The root cause evaluation of this event is in progress. The final root cause determination will be provided in a supplemental report. Corrective actions have been initiated to revise procedures, to change the alarm setpoint for the 8-hour average RTO, and add the 15-minute average RTO to the alarm response procedure. This event is not identified as a Safety System Functional Failure.U.S. NUCLEAR REGULATORY COMMISSION (1.2001)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL IREVISION Kewaunee Nuclear Power Plant 05000305 YEARQNUMBER NUMBER 2 of 4 2005 001 00 TEXT (I more space is required, use additional copies of NRC Form 366A) (17)

Event Description

On January 31, 2005, the Kewaunee Nuclear Power Plant (KNPP) was in operation at 100 percent rated thermal power of 1772 megawatts thermal (MWth). On day shift (0600 hrs to 1800 hrs), Instrument and Control (I&C) personnel were performing two surveillance test activities. These tests were being performed in accordance with Surveillance Procedure (SP) 47-316A (Channel [CHA] 1 (Red) Instrument Channel Test) and SP 05A-34C-1 (Feedwater Flow Transmitter [FT] Channel 1 (Red) Calibration). At approximately 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />, these surveillance activities caused the indications for reactor thermal power 1 -minute, 15-minute, and 8-hour averages to become inaccurate.

The Control Room operators entered abnormal operating procedure A-CP-46 (Abnormal Plant Process Computer System) to determine appropriate actions. The Alternate Reactor Thermal Output (ARTO) system was used to monitor reactor power. At approximately 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, the 1 -minute thermal power readings returned to approximately 1772 MWth. Procedure A-CP-46 was exited at approximately 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, and the use of ARTO was stopped. At the time, the 8-hour Reactor Thermal Output (RTO) average was viewed as not valid. The 1 -minute and 15-minute RTO values had returned to normal readings. Corrective Action Program document CAP 25257 was initiated by the Plant Process Computer System (PPCS) Group at 1453 hours0.0168 days <br />0.404 hours <br />0.0024 weeks <br />5.528665e-4 months <br />, to document the discrepancy in expected and actual reaction of the PPCS [CPU] to l&C surveillance activities.

The day shift operating crew initiated CAP 25258 to document the RTO being questionable as a result of performing procedure SP 05A-34C-1.

Turnover from day shift to night shift occurred at 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br />. Control Room Supervisor turnover items included review of questionable values resulting from l&C surveillance activities, the 8-hour average RTO indicating artificially low, and initiation of CAP 25258 that documented problems that occurred during SP 05A-34C-1 & questionable PPCS data. Reactor Operator turnover included discussion of previous dilutions and the thermal power PPCS trends, including the present 15-minute RTO being greater than 1772 MWth. Shift Manager turnover did not discuss actions to ensure the 8-hour average RTO remained below the license limit (for example keeping the 15-minute average RTO less than 1772 MWh). The night shift was aware that the 8-hour average RTO was reading low due to l&C activities on day shift. However, there was no direction given concerning the expected affect on the 8-hour average power indication, when the PPCS calculated 8-hour average value was validated. During the pre-shift brief, the night shift operations crew did not question the 8-hour average RTO indication. Also, the operating crew did not verify the 8-hour average RTO indication to monitor (PPCS or ARTO).

At 1952 hours0.0226 days <br />0.542 hours <br />0.00323 weeks <br />7.42736e-4 months <br />, the operating shift performed an 11 gallon dilution to compensate for normal core burn up. At both 2047 hours0.0237 days <br />0.569 hours <br />0.00338 weeks <br />7.788835e-4 months <br /> and 2057 hours0.0238 days <br />0.571 hours <br />0.0034 weeks <br />7.826885e-4 months <br />, the RTO 15-minute average PPCS alarm [JA] came in at 1773 MWth. These computer annunciators [ANN] each cleared within minutes. Shift management was not notified of either of these alarms, as they were expected due to the recent dilution, and there is no specific requirement to announce each computer alarm. As the effects of the l&C surveillance tests on day shift were being dropped from the 8-hour average calculation, the indicated 8-hour average power started to increase rapidly, resulting in the Trouble Light Annunciator (TLA)-1 1 "Reactor Thermal Power High" alarm (1772 MWth) at 2131 hrs.

Indicated 8-hour average reactor power peaked at 1772.07 MWth. Alarm Response Procedure (ARP) 47033-31 for TLA-1 1 was entered, a 3.4 gallon boration was performed at 2141 hours0.0248 days <br />0.595 hours <br />0.00354 weeks <br />8.146505e-4 months <br />, and 8-hour average power reduced to less than 1772 MWth at 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br />.U.S. NUCLEAR REGULATORY COMMISSION

.,(1.2001)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1 DOCKET NUMBER (2)

LER NUMBER (6 PAGE 3 Kewaunee Nuclear Power Plant 05000305 YEA NUMBER NER 3 of 4 2005 001 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

Event Analysis and Safety Significance This event is being reported under 1 OCFR50.73(a)(2)(i)(B), operation which was prohibited by the Technical Specifications.

The KNPP facility operating license states in Section 2.C.(1) - 'The NMC is authorized to operate the facility at steady-state reactor core power levels not in excess of 1772 megawatts (thermal)." NRC guidance relative to "Licensed Power Level" is contained in a letter from Mr. E. L. Jordan (Assistant Director for Technical Programs, Division of Reactor Operations Inspection, Office of Inspection and Enforcement), dated August 22, 1980. This guidance specifies the following:

• The average power level over any 8-hour shift should not exceed the full steady-state licensed power level (and similarly worded terms).

• The exact 8-hour periods are up to the plant. It is permissible to briefly exceed the full steady-state licensed power level by as much as 2 percent for as long as 15 minutes.

In no case should 102 percent power be exceeded.

Lesser power excursions for longer periods should be allowed (i.e. 1 percent excess for 30 minutes, 0.5 percent excess for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, etc). The 8-hour average power limit will prevent excessive multiple excursions.

The 8-hour average reactor thermal power maximum value was 1772.07 MWth for this event. This exceeded the 1772 MWth limit by only 0.07 MWth. The thermal power limitations given above relative to the 15-minute, 30-minute, and 1-hour time periods were not exceeded. The maximum 15-minute reactor thermal power value during this event was 1773 MWth.

Technical Specification 2.1, 'Safety-Limits - Reactor Core", requires that the combination of rated power level, coolant pressure, and coolant temperature shall not exceed the limits specified in the Core Operating Limits Report (COLR). The Reactor Core Safety Limits Curve was not exceeded. This event is therefore determined to have a very low safety significance. This event is identified as not being a Safety System Functional Failure.

Cause

The root cause evaluation of this event is in progress. The final root cause determination will be provided in a supplemental report. Any changes to the corrective actions, based on the results of the final root cause evaluation, will also be included in the supplemental report.

Corrective Action

1. Per Work Order 05-002811:

Add the reactor thermal power 15-minute average PPCS computer point as an input to Trouble Light Annunciator TLA-1 1 "Reactor Thermal Power High" alarm.

Reduce the TLA-1 1 alarm setpoint for the 8-hour average thermal power to 1771.7 MWth.

2. Revise ARP 47033-31 (TLA-1 1) to add the 15-minute thermal power alarm setpoint of 1772 MWth, change the 8-hour thermal power alarm setpoint to 1771.7 MWth, and to provide additional action to use the Valve Position Limiter (VPL) to lower turbine power as recommended actions.U.S. NUCLEAR REGULATORY COMMISSION (1.2001)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITYNAME(1)

DOCKET NUMBER(2)

LERNUMBER6 PAGE (3)

I YEAR SEQUENTIAL REVISION I Kewaunee Nuclear Power Plant 05000305 Y

001BE NUMBER 4 of 4

__2005 001 00 TEXT (if more space Is reqtdred, use additional copies of NRC Forn 366A) (17)

3. Revise procedure A-CP-46 to clarify guidance to monitor reactor power, add steps to ensure 1772 MWth is not exceeded when the PPCS is out-of-service, and to clarify conditions to return to using the PPCS RTO program monitoring.

4. Revise procedure N-0-03 (Plant Operation Greater Than 35% Power) to reference the 1771.7 MWth setpoint, and to add a note to ensure the nominal maximum reactor power 8-hour average is maintained below 1771 MWth.

5. Revise General Nuclear Procedure (GNP) 03.17.10 (Reactivity Management) to discuss the responsibility of the operating crews to maintain the steady state power less than 1772 MWt, as described in the KNPP operating license. This discussion is to define the plant philosophy on maintaining reactor power within the license limit.

6. Perform a review of other alarm setpoints that are set at Technical Specification (TS) values, and potentially would not allow sufficient time for Operations to take action before a TS required value is exceeded.

7. Revise procedures SP-05A-034C-1, 2, 3, & 4. In each SP, Step 6.2.5 identifies which channels are the controlling channels and then states to 'N/A' Steps 6.2.6 through 6.2.9. Step 6.2.6 removes the selected channel from PPCS scan, and this step should not be marked as 'N/A'.

Previous Similar Events

KNPP LER 92-18; Licensed Power Exceeded Due To Inaccurate Feedwater Flow Indication On September 22,1992, the plant was returning to 100 percent power after a unit trip. After applying the ultrasonic flow meters (UFMs) correction factor to in-line venturi feedwater (FW) flow measurements and escalating to 100 percent power, it was noted that the electric output was 1 to 2 megawatts higher than before the unit trip. An evaluation determined indicated FW flow, measured by the UFMs, was 0.41 percent low and reactor power was approximately 0.2 percent greater than licensed thermal power. Immediate actions were taken to decrease power to within licensed limits. The change in UFM output was caused by corrosion product build up between the UFM transducers and the FW pipe in conjunction with age related degradation of the transducers.

The FW UFMs were calibrated, using the full flow bypass line venturi, to accurately measure FW flow.