ML20065S812

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Requests Commission Reconsider Util & Proposed Tech Spec Changes Re Inoperability of Reactor Protection Sys/Esf Actuation Sys channels.Forty-eight Hours Insufficient Time for Repairs
ML20065S812
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 10/27/1982
From: William Jones
OMAHA PUBLIC POWER DISTRICT
To: Clark R
Office of Nuclear Reactor Regulation
References
LIC-82-354, NUDOCS 8211020045
Download: ML20065S812 (2)


Text

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Omaha Public Power District 1623 HARNEY a OMAHA. NE5RASMA 68102 e TELEPHONE 536-4000 AREA CODE 402 October 27, 1982 LIC-82-354 Mr. Robert A. Clark, Chief U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Licensing Operating Reactors Branch No. 3 Washington, D.C. 20555

Reference:

Docket No. 50-285

Dear Mr. Clark:

Fort Calhoun Station Technical Specifications (TS)

Amendment Application Regarding Inoperability of RPS/ESFAS Channels The Comission's letter to Omaha Public Power District dated September 20, 1982 delineated changes to the District's TS amendment application dated July 22, 1980, as supplemented by letter dated June 15, 1982, that would be acceptable to the Comission for resolving the subject issue. The District has given careful consideration to the staff's proposed TS changes and continues to have concerns on implementing these changes for the reasons detailed below.

l The District's June 15, 1982 amendment application supplement requested i that for the purpose of testing and maintenance, a single inoperable I

high power level, thermal margin / low pressurizer pressure, and axial l power distribution channel may be bypassed for 7 days if the inoper-ability is determined to be a result of malfunctioning RTD's or nuclear detectors. The District has requested this additional channel bypass time for the above described circumstances and channels because the normally inaccessible RTD's and nuclear detectors require a reasonable amount of time to repair and because of a concern regarding the in-creased probability for spurious tripping of the plant. The District is concerned that 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is not sufficient time to effect repairs and that the inoperable RPS channel will then have to be placed in the tripped position, resulting in a 1-out-of-3 channel trip logic. Operating experience at the Fort Calhoun Station has demonstrated that channel 3 noise can also result in the tripping of a channel and, thus, the l potential for spurious plant trips is obvious. The District believes 11 the potential economic loss from these spurious trips is not comensurate with the incremental increase in purported safety achieved by solely utilizing the 48-hour bypass criteria for all RPS channels. In addition, 8211020045 821027 PDR ADOCK 0500028' P PDtt

Mr. Robert A. Clark LIC-82-354 Page Two it is the District's engineering judgment that these spurious trips can increase the number of challenges to the Fort Calhoun Station safety systems. The District believes that any gain in safety achieved through the Commission's proposed changes may be negated by these system chal-lenges and transients. Finally, maintaining the RPS/ESFAS channels in an operable condition is of prime importance in this issue, and the District's proposed 7 day bypassing can achieve this purpose and still maintain a high degree of safety to the plant and public during this time.

The District's proposed TS's for the high rate trip-wide range log channels, as detailed in the June 15, 1982 submittal, are justified since this system is not credited in the Updated Safety Analysis Report (USAR). As stated in the Discussion section of the subject letter, these channels perform an anticipatory function and are redundant to the Variable Over Power Trip (V0PT) circuit of the high power level trip system. Because there will be no reduction in plant safety by imple-menting the District's proposed TS's for these channels, the District believes the TS's, as proposed in our June 15, 1982 letter, are still valid.

The District respectfully requests that the Commission reconsider the District's June 15, 1982 letter and proposed TS's detailed therein. The potential economic impact, additional challenges to safety systems, the design and perfonnance of the existing protective systems, and the estimated cost for a backfit to provide additional redundancy are several pertinent items which should be included in your consideration of this issue.

Sincerely, W.'C. Jones Division Manager Production Operations WCJ/TLP:jnm

! cc: LeBoeuf, Lamb, Leiby & MacRae

, 1333 New Hampshire Avenue, N.W.

i Washington, D.C. 20036 Mr. E. G. Tourigny, NRC Project Manager

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