05000458/LER-1993-015
| ML20056F594 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/23/1993 |
| From: | Booker J, Lorfing D GULF STATES UTILITIES CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LER-93-015, LER-93-15, RBG-38912, NUDOCS 9308300127 | |
| Download: ML20056F594 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 4582093015R00 - NRC Website | |
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GULF STATES UTILITIES COMPANY , af ;
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August 24, 1993 j RBG- 38912 File Nos. G9.5, G9.25.1.3 l l
U.S. Nuclear Regulatory Commission Document Control Desk ;
Washington, D.C. 20555 Gentlemen: ,
River Bend Station - Unit 1 Docket No. 50-458 i
Please find enclosed Licensee Event Report No.93-015. This report is submitted ,
pursuant to 10CFR50.73. .
Sincerely, !
t f.B&& l J. E. Booker l Manager - Safety Assessment l and Quality Verification River Bend Nuclear Group :
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cc: U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 NRC Resident Inspector P.O. Box 1051 St. Francisville, LA 70775 INPO Records Center 1100 Circle 75 Parkway Atlanta, GA 30339-3064 ;
Mr. C.R. Oberg Public Utility Commission of Texas 4 7800 Shoal Creek Blvd., Suite 400 Nonh Austin, TX 78757 ,
i Depanment of Environmental Quality Radiation Protection Division P.O. Box 82135 Baton Rouge, LA 70884-2135 A'ITN: Administrator ,
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a CRC FORM 366 'U.S. NUCLE AR REGULATCCtY C(MMISSION GPP20VED BY CMB No. 3150-0104 (5 92) EXPIRES $/31/95 ESTIMATED BURDEN PER RESPONSE 10 COMPLY WITH THIS lhFORMAT]DN COLLECTION REQUEST: 50.0 ERS.
LICENSEE EVENT REPORT (LER) FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO lHE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLE AR REGULATORY COMWlESION, (See reverse for required nJnber Cf digits /chDTaCterb for each blDek) WAS H I N GT ON , DC 20555-0001, AND TO THE FAPERWORK REDUCT:0N FROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WA S H I N GT ON , DC 20503.
FACILITY NAME (1) DOCKET NLMBER (2) l PAGE (3)
RIVER BEND STATION 05000458 l 1 OF 4 TITLE (4) TIME RESPONSE TESTING Of ISOLATION INSTRLMENT ATION FOR THE REACIOR WATER CLEANUP AND REACTOR CORE ISOLATION l COOLING SYSTEMS NOT PERFtRMED AT THE INTERVALS REQUIRED BY THE TECHNICAL SPECIFICATIONS EVE NT DATE (5) l L E R NtMRER (6) REPORT DATE (7) OTHER F ACIL ITIES INVOLVED (B)
MONTH CAY YEAR YEAR MONTH OAY YEAR NUMBER NUMBER DE000 07 WE D MET NUMBER 23 93 93 --015-- 00 08 23 93 05000 OPE RAT ING THIS REPORT IS SURMITTED PURSUANT TO THE REQUIREMENTS Of' 10 CFR b- (Check one or mnre) (11) l MODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73. 71 ( b) 3 POWE R 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) 0 LEvit (10) . 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a)(1)(iii) x 50.73(a)(2)(i) 50.73(a)(2)rviii)(A) (Specify in A t act ow 20.405(*)(1)(iv) 53.73(a)(2)(ii) 50.73(a)(2)(viii)(B) 20.405(a)(1)(v) 50.73(a)(2)(iii) .50.73(a)(2) u) Nat Form 366A)
!!CENSEE CONTACT FON THIS lER (12)
- David N. Lorfing, Supervisor - Nuclear Licensing TELEPHONE (504)-381-4157 4
COMPLETE ONE TINE IOR E ACH CCMPOWENT I Allure DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONEAT MANUFACTURER 0 D SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED M*I " #
YE S NO SUBMISSION (11 yes, complete EXPECTED SUE #1SS10N C ATE), 1 DATE (15)
ABSTRACT (Limit to 1400 spaces, i.e., apprcximately 15 single-spaced typewritten lines) (16) f On July 23.1993 with the plant in Operational Condition 4 (Cold Shutdown), a deficiency in plant surveillance test procedures (STPs) was identified. During a technical review of surveillance test scheduling requested by the STP scheduling coordinator, it was discovered that the time response testing of the isolation instrumentation of the reactor water cleanup (RWCU) and reactor core isolation cooling (RCIC) systems was not being performed at the proper time intervals. The last performance of these STPs such that the TS requirements were met was on October 18,1985. This repon is submitted pursuant to 10CFR50.73(a)(2)(i)(b) as opemtion prohibited by the Technical Specifications. All instrument response times were found to be within tolerance. Based on these results, there is a high degree of confidence that these response times have been within tolemnce since their last performance.
NRC FORM 366 (5-92)
NRC FORM 3f4A U.S. CUCLEAR REGULATO7 (%DMISSIC APPROVED BY OMB CD. 3?50-0704 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
I LICENSEE EVENT REPORT (LER) E *17,OEg$ $ x [ RIcOYoS*7[g"ct[gYgu$
m TEXT CONTINUATION (MNE>B 7714), U.S. NUCLEAR REGULATORY COMMIS$10N, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK kEDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGCT, WASHINGTON, DC 20503.
FACIt!TY NAME (1) DOCKET NLMRER (2) (ER NtMRf R (6) PAGE (3)
RIVER BEND SIATION SEQUENTIAL REVISION YEAR 05000458 93 0 2 OF 4
--015 --
1 TEXT (If more space is reavired. use additional copies of NRC Form 366A) (17)
REPORTED CONDITION On July 23,1993 with the plant in Opemtional Condition 4 (Cold Shutdown), a deficiency in plant i surveillance test procedures (STPs) was identified. During a technical review of surveillance test scheduling requested by the STP scheduling coordinator, it was discovered that the time response testing of the isolation instrumentation of the reactor water cleanup (RWCU) (*CE*) and reactor core isolation cooling '
(RCIC) (*BN*) systems was not being performed at the proper time intervals. 1 Technical SpeciHcation (TS) Table 3.3.2-3 and TS 4.3.2.3 requires that a time response test be perfonned once every 18 months except where there are redundant channels. In cases where there are redundant channels it is required that each test shall include at least one channel per trip system such that all channels are tested at least once every 18 months, multiplied by the number of redundant channels in a specific isolation trip system. The last perfonnance of these STPs such that the TS requirements were met was on i October 18,1985. This report is submitted pursuant to 10CFR50.73(a)(2)('i)(b) as operation prohibited by l the Technical Specifications. ,
There were 6 STPs in which this requirement was not met. These STPs are the isolation instmmentation response time tests for RWCU s.igh differential flow (A and B), RCIC high steam line flow (A and B). and RCIC low supply pressure (A and B) instmments. The STP numbers are respectively, STP-207-4809 and STP-207-4810, STP-207-4811 and STP-207-4812, STP-207-4813 and STP-207-4814. Subsequent perfonnance of the STPs assures that the equipment is operable.
INVESTIGATION The RWCU high differential flow instmmentation is designed to monitor the inlet flow to the RWCU system and the two outlet Hows from this system and compare these to each other. If the inlet and outlet flows have too great a difference this would indicate a leak in the RWCU system and the instrumentation would cause a system isolation. There are two independent instmment channels, channel A and channel B.
Each channel is designed to isolate the RWCU system but they accomplish this by closing different isolation ,
valves. One channel closes the inboard isolation valves while the other closes the outboard isolation valve. i A review of how STP-207-4809 and STP-207-4810 were being scheduled revealed that these STPs were being scheduled as though they were redundant channels of the same trip system. One channel was performed in the first 18 month period followed by the other during the next 18 month period.
NRC FORM 366A (5-92)
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CRC FORM 3!4A
- u.S.11JCLEAR RE(llLATC2Y COMMISSICQ APPROVED BY OMB IX). 3150-0104 (s-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS IkFORMAT ION COLLECTION REQUEST: 50.0 HRS.
- FORWARD COMMENTS REGARDING BURDEN ESilMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MAAAGEMENT LRANCH TEXT CONTINUATION (MASB 771'), u.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, LASHINGTON, DC 20503.
FACILITY NAME (1) DOCKET NtMBER (?) LER WlMBER (6? PAGE (3)
RIVER BEND STATION CEQUENTIAL REVISinN YEAR 05000458 93 0O 3 OF 4
-- 015 --
TEXT (If more space is required use additional ropies of NRC >rm 366A) (17)
A characteristic of redundant channels is that, while each channel independently monitors a parameter, both channels cause the same actuation to occur. Since each of these channels is completely independent of the other and closes different valves, these channels cannot be considered to be redundant channels of the same trip system. Each must be considered a trip system in itself. This being the case, both of these STPs (207- '
4809 and 207-4810) must be performed every 18 months in accordance with TS 4.3.2.3.
Based on a review of the STPs, TS Table 3.3.2-3.4.a, and TS 4.3.2.3 it is apparent that the surveillance requirements were not met. The STPs were being perfonned on a 36 month frequency instead of the correct 18 month frequency. A search through previous perfonnances of these STPs showed that the last time that all of the surveillances were perfonned was between October 2,1985 and October 18, 1985. Based on the correct perfonnance of the surveillances on these dates, three of the six suneillances became overdue i between August 22,1987 and September 1,1987. Since that time three of the six suncillances have been overdue.
The RCIC high steam flow instrumentation and the RCIC low steam supply pressure instrumentation has logic identical to the RWCU high differential flow instnlmentation. In all three cases each instrument '
channel (A and B) is completely independent and actuates different isolation valves. Using the same logic as applied to RWCU system above, it is apparent that each of these channels must also be considered a trip system and scheduled every 18 months.
ROOT CAUSE A change analysis was performed which revealed that the initial schedule development was incorrect due to either incorrect analysis of the systems involved or misinterpretation of the Technical Specification.
A review of previous LERs revealed several cases of STP scheduling errors. However, this event involved an inadequate understanding of the systems, and therefore, the TS requirements. None of the previous LERs involving scheduling errors had this characteristic.
CORRECTIVE ACTION Surveillance test procedures (STPs) 207-4810,207-4812, and 207-4814 were completed successfully on July 25, 1993. Surveillance test procedures (STPs) 207-4809, 207-4811, and 207-4813 had been perfonned during the last refueling outage and were current. Perfonnance of these STPs restored the RCIC and RWCU systems to an operable status.
The STP scheduling group will be provided with specific instmetions on the scheduling of STPs with irregular frequencies. These instructions will be reviewed and appmved by Maintenance management, System Engineering, and Licensing to ensure technical accuracy and compliance with the applicable NRC FORM 366A (5-92)
WRC FORM 366A U.S. C33 CLEAR REGULATO7 CDPMISS!(O APPROVED BY OMB No. 3750-0104 (5-92) EXPIRES 5/31/95
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ESTIMATED BURDEN PER RESPONSE TO CtMPLY WITH THIS INFORMATION CoiLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO
, LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB m 4), u.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO TPE PAPERWORK REDUCTION FROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET. WASH!NGTON, DC 20503.
FAClllTY NAME (1) DOCKET NLMBER (2) trR NtMRFR (6) PAGE (3)
R!VER BEND STATION SEQUENT I AL REVIS10W YEAR NUMBER NUMBER 05000458 4 OF 4 93 -- 015 -- 00 TEXT (If more space is reavired, use additional copies of NRC Form 366A) (17)
Technical Specifications. All STPs having irregular frequencies were reviewed and no additional problems were identified.
SAFETY ASSESSMENT Although the surveillance requirements for TS 4.3.2.3 were not perfonned on the required 18 month frequency, they were effectively scheduled for every 36 months. Following this event, STP-207-4809, STP-207-4811, and STP-207-4813 were performed successfully. All instrument response times were found l to be within tolerance. Based on these results, there is a high degree of confidence that these response times have been within tolerance since their last performance.
Note: Energy industry idet..-Gcation codes appear in the text as (*XX*).
NRC FORM 366A (5-92)