View source for RBG-24143, Requests Extension to 18-month Surveillance of Turbine Overspeed Protection Sys,Per Tech Spec 3/4.3.8,until 861004 to Correspond W/Next Scheduled Outage When Reactor in Mode 3,4 or 5

{{Adams
| number = ML20214J929
| issue date = 08/04/1986
| title = Requests Extension to 18-month Surveillance of Turbine Overspeed Protection Sys,Per Tech Spec 3/4.3.8,until 861004 to Correspond W/Next Scheduled Outage When Reactor in Mode 3,4 or 5
| author name = Deddens J
| author affiliation = GULF STATES UTILITIES CO.
| addressee name = Martin R
| addressee affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION IV)
| docket = 05000458
| license number = 
| contact person = 
| document report number = RBG-24143, NUDOCS 8608150234
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE, UTILITY TO NRC
| page count = 2
}}

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{{#Wiki_filter:s GULF STATES                       UTILITIES COMPANY RrVER BEND STATION    POST OFFICE BOX 220     ST FRANCISVILLE. LOUISIANA M77$
AREA CODE 604    635-6094      346-8651 August 4, 1986 RBG- 24143 File Nos. G9.5 Mr. Robert D. Martin, Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000                                                            hh]Q]          -
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4 Arlington, TX 76011                                                                     {j g ,,,              ,l

==Dear Mr. Martin:==
River Bend Station - Unit 1                                                 ~ ~ ~ ~ ~
i Docket No. 50-458 Gulf States Utilities                  (GSU)         is submitting by this letter a request for extension to an 18 month surveillance of the turbine overspeed   protection                system             as         speci fied            by    Technical Specification 3/4.3.8. Taking into consideration the maximum allowable extension for the surveillance interval, the 18 month channel calibration vould be required to be performed                                                  by September   11,          1986.            GSU         is requesting to extend this surveillance to October 4,                   1986 to correspond with the next scheduled outage as this surveillance can only be performed while in modes 3, 4 or 5.
The turbine overspeed protection system does not directly impact any safety related plant systems or functions. The 18 month surveillance only ensures the calibration of                                                the   turbine overspeed protection circuitry. GSU last performed this channel calibration on October 21, 1984 during the preoperational test program. GSU also performed an overspeed trip test of the River Bend Station turbine during the start-up and test program.                                           This test was   successfully performed on December 24, 1985 with both the mechanical and electrical overspeed trip functions being checked and found to be within specifications. In addition, the turbine overspeed protection system is tested                                                weekly   per Technical Specification surveillance by the closure and fast closure functional testing of all turbine steam valves                                              (stop valves, control valves and combined intercept valves). GSU performs a weekly test on the mechanical overspeed trip mechanism and the trip circuits are tested weekly by performing the electrical and backup overspeed trip.
8608150234 860804 PDR P
ADOCK 05000450                                                                                    \ko
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m Mr. Martin                                         August 4, 1986 The turbine overspeed protection does not directly impact any safety related plant system or functions and statistically, the probability of a missile generated by a turbine overspeed negatively affecting a safety related system is very small.
General Electric (GE) has documented to GSU a recommendation that this type of calibration need be performed only if problems are noted within the system or at convenient major outages. GE also noted that this surveillance be performed at least every 4 years.
Finally,   it should be noted that if River Bend Station should enter into an unscheduled major outage prior to the requested October 4,    1986 date, GSU will perform this surveillance test prior to restart of the unit.
Sincerely,
                                                                 =v J. C. Deddens Vice President River Bend Nuclear Group JCD/ER      /je
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