ML20197H394

Submits Conclusions Re Review of Concerns Noted in to DG Eisenhut Re Response Time Testing of Turbine Stop Valve Closure,Reactor Scram & end-of-cycle Recirculation Pump Trip Functions at Facility

ML20197H394
Person / Time
Site:	LaSalle
Issue date:	11/14/1986
From:	Bernero R Office of Nuclear Reactor Regulation
To:	Norelius C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20197H361	List: ML20197H356 ML20197H374 ML20197H394
References
FOIA-99-41 TAC-57194, NUDOCS 9812140074
Download: ML20197H394 (2)

Text

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'4 -l W ASHINGTON,0. C. 20655 l k.....,/ /lft l MEMORANDUM FOR: C. E. Norelius Director l Division of Reactor Projects. Region III FROM: R. Bernero, Director Division of BWR t.icensing, NRR

SUBJECT:

TO RESOLVE ISSUES 9 ELATIVE TO SCRAM RESPONSE TIME TESTING FOR LASfLLE COUNTY NUCLEAR STATION AND POSSIBLE

, INDUSTRY WIDE CONCERNS IN THIS AREA (TAC No. 57194, TIA NO. 83-52) i Your letter dated April 22, 1983 to D. G. Eisenhut raises concerns regarding i response time testing v. Turbine Stop Valve Closure 'TSVC), reactor scram and End-of-Cycle Recirculatien Pump Trip (E0C-RPT) functions at LaSalle Nuclear Power Station. Due to the NRR re-organization, this request which was originally issued to ICSB in DS!, in May 1983 was recently transferred to E!CSB/ DBL for necessary action.

E!CSB/ DBL, has reviewed the concerns raised by you and has concluded the following: .

Technical Specification 1.33 defines the reactor protection system response time as the time interval from when the monitored parameter exceeds its trip set point at the channel sensor until de-energization of the scram pilot valve solenoids. The channel sensor for turbine stop valve closure (TSVC) function is its limit switch. The same limit switch which initiates the TSVC scram also . initiates the TSVC EOC-RPT. The actual measurement of response time of the limit switch is not practicable as this test is done during the refueling outage when the turbine stop valves are fully closed and thus the limit switch in the RPS circuitry is open. In order to do RPS response time of TSVC, the licensee has installed a test switch in parallel with the limit switch to simulate the limit switch function and allows 10 ms for the response time of the limit switch. Table 3.3.1-2 of Technical Specifications specifies the response time of TSVC to be 60 ms and the records kept by the licensee show the average response time of TSVC as 48 ms. The licensee states that General Electric has conducted tests for similar type limit switches and the response time of those limit switches was consistently found to be in the range of 0-1 ms. Therefore, we believe that the response time of the test switch conservatively models the response time of the limit switch.

Based on the above, we conclude that the current method of performing the response time verification test for TSVC at LaSalle is reasonable and will provide CONTACT: N. Trehan EICSB/ DBL X27589 3 . '3 M 9812140074 981204-PDR FOIA GRABER99-41 PDR

2 HON 14 $6 adequate assurance that scram responsa timo for this function is within technical specification limit.

This closes TAC 57194 and TIA 83-52.

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R. Bernero. Director i

Division of BWR Licensing l

Office of'Huclear Reactor Regulation cc: E. Jordan IE G. Lainas M. Srinivasan G. Holahan E. Adensam A. Bournia N. Trehan ,

DISTRI6UTION Central Files EICSB R/F RBernero DVassallo

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