05000281/LER-2009-001, Regarding Manual Reactor Trip Initiated to Replace a Rod Control Data Logging Card
| ML112081979 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 01/28/2010 |
| From: | Gerald Bichof Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 10-055 LER 09-001-00 | |
| Download: ML112081979 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 2812009001R00 - NRC Website | |
text
{{#Wiki_filter:" 10CFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 January 28, 2010 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001
Dear Sirs:
Serial No.: 10-055 SPS: BAG Docket No.: 50-281 License No.: DPR-37 Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 2. Report No. 50-281/2009-001-00 This report has been reviewed by the Station Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review. uly yours, ,~~ eraJd T. Bischof, Site Vice President Surry Power Station Enclosure Commitment contained in this letter:
- 1. Review results of the replaced Supervisory Data logging Card tests to determine options to reduce future failures.
cc: United States Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Senior Resident Inspector Surry Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION i'>PPROVED BY 1MB: NO. 31S()-{)104 EXPIRES 08/3112010 (9-2007) Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are Incorporated inlo the licensing process and fed back to industry. Send comments regarding burden estimale to the Records and FOINPrivacy Service Branch (T-5 F52), U. s. LICENSEE EVENT REPORT (LER) Nuclear Re~ulatOry Commission, Washington, DC 20555-0001, or bYc Internel eHT1an to In ocol/ects@nrc.gov, and to the Desk Officer. Office of In ormation and Regulatoly Affairs, NEOB-10202, (3150-0104). Office of Management and Budget. Washington, DC 20503. If a means used to Impose an Information (See reverse for required number of collection does not display a currenfly valid OMS control number. the NRC may not conduct or sponsor, and a person Is not required 10 respond 10. the digits/characters for each block) information collection.
- 1. FACILITY NAME I
- 2. DOCKET NUMBER
- 3. PAGE Surry Power Station 05000* 281 1 OF 4
- 4. TITLE Manual Reactor Trip Initiated to Replace a Rod Control Data Logging Card
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR ISEQUENTIALI REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR 05000 11 29 09 2009 - 001 00 01 28 10 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITIED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all/hal app!v) o 20.2201(b) 0 20.2203(a}(3}(1) 0 50.73(a}(2}(I}(C)
D 5O.73(a}(2)(vii) N o 20.2201(d) o 20.2203(a}(3}(11) 0 SO.73(aX2XII}(A) o 50.73(a}(2)(viil}(A) o 20.2203(a)(1) o 20.2203(a)(4} 0 50.73(a}(2}(i1)(8} D 50.73(a)(2}(viii}(B) o 20.2203(a}(2)(i) o 5O.36(c)(1}(iXA) 0 50.73(a}(2}(1IJ) o 50.73(a}(2}(ix}(A)
- 10. POWER lEVEL o
20.2203(a){2)(il) o 50.36(C)(1)(i1)(A} [II SO.73(a}(2)(iv}(A} o 50.73(a}(2)(x) U 20.2203(a)(2}(iii) o 50.36(c)(2) o 5O.73(a){2){v}(A) o 73.71(a){4} 0% o 20.2203(a)(2Xiv} o 50.46(a){3}(ii) o 50.73(a){2){v}(B) o 73.71(a){5) o 20.2203(a)(2}(v) o SO.73(a)(2){i)(A) o SO.73(a){2}(v){C} D OTHER o 20.2203(a){2){vi} D SO.73(a){2){I){B} D 50.73(a}(2){v){D) SpeCify in Abstract below or In NRC F0!Tl1366A
- 12. LICENSEE CONTACT fOR THIS lER FACILITY NAME ITELEPHONE NUMBER (IncludeAres COde)
Brandford L. Stanley, Director Safety and Licensing (757) 365-2003ICOMPONENT I
CAUSE
SYSTEM MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX X AA DAL W120 Y I
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH I DAY YEAR DYES (Iryes, complete 15. EXPECTED SUBMISSION DATE)
[II NO SUBMISSION I DATE I ABSTRACT (Limn to 1400 spaces,l.e., approximately 15single-spaced typewritten lines) On November 29, 2009 at 0808 hours, with Unit 2 reactor critical, operators identified a discrepancy between Control Bank 'B' (CBB) Group 1 and Group 2 step demand counters (SOC) during startup physics testing. At 1045 hours, the decision was made to manually trip Unit 2 to replace a Supervisory Data Logging Card in the Rod Control System Logic Cabinet. Replacing the card would disable multiple group SDCs. The card was replaced, rod control system tested, and the system returned to service. At 2150 hours, Unit 2 reactor achieved criticality and startup physics testing continued. When the reactor was manually tripped, the control rods promptly inserted and all systems responded as expected. The Supervisory Data Logging Card will be tested and results reviewed to determine the cause of the discrepancy. Based upon the test results, options will be reviewed to reduce future failures. The reactor trip resulted in no significant safety consequences or implications and the health and safety of the public were not affected. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A), manual actuation of the reactor protection system (RPS). NRC Form 36M (9*2007) PRINTED ON RECYCLEO PAPER
1.0 DESCRIPTION OF THE EVENT On November 29, 2009 at 0527 hours, Unit 2 reactor achieved criticality following the Fall refueling outage. With reactor power stable, startup physics testing commenced at 0555 hours. At 0808 hours, while inserting Control Bank 'B' (CBB) in accordance with the startup physics test procedure, the operators identified a discrepancy between Group 1 and Group 2 Step Demand Counters (SOC) [EIIS-AA,CTR]. CBS bank was being inserted from 230 steps when the operator noticed that when Group 1 SOC stopped at 213 steps, the Group 2 SOC continued to increment. The startup physics test was suspended with Group 1 at 213 steps and Group 2 at 210 steps. System Engineering reviewed the indications and determined that the condition 'resulted from a probable fault on the Supervisory Data Logging Card A114 [EIIS-AA,DAL]in the Rod Control System Logic Cabinet [EIIS-M,CAS]. The output signals for Shutdown Bank B, Control Sank 8, and Control Bank D step counters are provided by Card A114, therefore, a Technical Specification (TS) 6-hour Hot Shutdown (HSD) action statement was entered for multiple inoperable SDCs. Due to the time reqUired to safely replace the card and perform post maintenance testing (PMT), the decision was made to manually trip the reactor. At 1045 hours on November 29, 2009, Unit 2 reactor was manually tripped and procedure 2-E-0, Reactor Trip Response, was initiated. All systems functioned as reqUired. Initiation of auxiliary or emergency systems was not required. Heat removal was maintained by steam generator blowdown [EllS-WI], main feedwater [EIIS-SJ], and the steam generator power operated relief valve [EIIS-SB,RV]. At 1331 hours on November 29, 2009, a hon-emergency, four-hour notification was made to the NRC pursuant to 10 CFR 50.72(b)(2)(iv)(B), any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A), manual actuation of the reactor protection system (RPS). 2.0
SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
This event resulted in no significant safety consequences or implications. At the time of the manual trip, the reactor was stable below the point of adding heat and reactor power was approximately 5 x 10*a amps on the intermediate range nuclear instrumentation [EIIS-IG]. The control rods promptly inserted as designed when the reactor was manually tripped. The safety injection [EllS-SO] and auxiliary feedwater.(9-2007) U. S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE YEAR Surry Power Station I
SEQUENTIAL I REV NUMBER NO. 05000 w 281 I-----L...---........J'-----{ 2009 ~ 001 ~ 00 30f4 [EllS-SA] systems did not actuate and were not needed due to plant conditions. There were no radiation releases due to this event. Therefore, the health and safety of the public were not affected. 3.0
CAUSE
The cause for the reactor trip was the need to place the reactor in a safe condition to replace and test the Supervisory Data Logging Card A114. Replacing the Supervisor Data Logging Card A114 would disable the output signals for Shutdown Bank B, Control Bank B, and Control Bank D step demand counters and would require entry into a TS 6-hour HSD action statement. After Card A114 replacement. a visual inspection found no noticeable overheated or cracked components. The card was sent for further testing. 4.0 IMMEDIATE CORRECTIVE ACTION(S) The Supervisory Data Logging Card A114 was replaced. The PMT test, requiring Shutdown Bank B, CBB, and Control Bar:lk D to be withdrawn 10 steps and inserted 8 steps, one bank at a time, was performed and all three banks indicated correct rod motion on the step counters, the plant computer system [EIIS-ID], and the computer enhanced rod position indicator (CERPI) system. The rod control system was returned to service and the Unit 2 reactor achieved criticality at 2150 hours on November 29, 2009. 5.0
ADDITIONAL CORRECTIVE ACTIONS
The Supervisory Data Logging Card was sent for further testing and the results of the testing will be reviewed to determine the cause of the output discrepancies. 6.0 ACTIONS TO PREVENT RECURRENCE When the testing and analysis of the Supervisory Data logging Card is complete, options will be reviewed to reduce future failures. 7.0
SIMILAR EVENTS
On January 30,2008, with Surry Unit 2 operating at 100% power and the Rod Control System in automatic, the Supervisory Data Logging Card A114 was determined to be malfunctioning. Failure analysis determined that a Motorola high threshold logic (MHTL) chip had failed in the high position preventing the step NRC Fonn 36M (9*2007)(9-2007) U. S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) CONTINUATION SHEET
- 1. FACILITY NAME Surry Power Station
- 2. DOCKET
- 6. LER NUMBER YEAR 2009 001
- 3. PAGE 40f4 counter to increment in the inward direction. The Unit 2 Card A114 was replaced and a preventive maintenance activity was scheduled for the 2008 Spring refueling outage. In May 2008, the Westinghouse Full Length Rod Control Enhanced Maintenance package was completed on Unit 2 Rod Control System with no major concerns noted.
8.0 MANUFACTURER/MODEL NUMBER The reactor coolant system Logic Cabinet Supervisory Data Logging Card, model number 3361 C08G01, is manufactured by Westinghouse. 9.0
ADDITIONAL INFORMATION
During subsequent physics testing, the CBB Group 2 SDC failed at 0004 hours on November 30,2009. Physics testing was suspended, the failed Group 2 counter was replaced, PMT testing completed, the rod control system returned to service, and physics testing was resumed. An evaluation determined that the Supervisory Data Logging Card issue and the Group 2 step counter issue were not associated. Unit 1 was at 100% power and remail')ed unaffected by the Unit 2 event. NRC Form 36GA (9'2007) }}