ML20153D370
| ML20153D370 | |
| Person / Time | |
|---|---|
| Issue date: | 08/09/1996 |
| From: | Burrows F NRC (Affiliation Not Assigned) |
| To: | Wermiel J NRC (Affiliation Not Assigned) |
| Shared Package | |
| ML20153D328 | List: |
| References | |
| RTR-REGGD-01.105, RTR-REGGD-1.105 NUDOCS 9809250043 | |
| Download: ML20153D370 (2) | |
Text
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/ g j UNITED STATES NUCLEAR REGULATORY COMMISSION
'o WASHINGTON, D.C. 3000H001
%, +'#,8 August 9, 1996 MEMORANDUM TO: Jared S. Wermlel, Chief Instrumentation and Controls Branch ,
i Division of Reactor Controls and Human Factors Christopher I. Grimes, Chief Technical Specifications Branch l Associate Director for Projects FROM:
Frederick H. Burrows, Electrical Engineer Electrical Engineering Branch
- Division of Engineering
SUBJECT:
PROPOSED REVISION 3 TO REGULATORY GUIDE-1.105,
" INSTRUMENT SETPOINTS FOR SAFETY SYSTEMS" As a result thoughts forofyour my cursory review of the subject document, I have the following consideration:
In ligt.t of the fact that the staff has in the past approved Technical Specifications with only a setpoint or recently with only an allowable value how does this match up-with the last two sentences of Regulatory Position 3 "hich state:
t The standard technical specifications (STS) accommodate the LSSS through the allowable value and the trip setpoint. A TS incorporating a setpoint column only (with the tolerances and limits controlled within plant procedures) does not accommodate l
the requirements of an LSSS and is not consistent with 10 CFR 50.36.
Does this mean the staff has not been consistently applying 10 CFR 50.36? Does this mean the plants licensed with only a setpoint and no allowable value are not meeting 10 CFR 50.367 Regulatory Position 4 correctly states that:
The NRC staff considers the allowable value to be the limiting value that the trip setpoint can have when tested periodically,
' beyond which the instrument channel is considered inoperable and TS corrective action must be taken.
But once again the importance of the nominal setpoint has been downplayed. In my opinion, at the end of the channel surveillance, the i
instrumerit channel setpoint must be left within the nominal setpoint i
i range or future operability is questionable. With the vague wording contained in the latest STS's, we now must rely on the Itcensees to have i
plant precedures to ensure future operability.
9809250043 980915 PDR TOPRP EMVWEST C PDR Gf a9 3 fc.W()
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4 Multiple Addressees ,
The staff is still going forward calling the allowable value an LSSS. I 1 was not here when 10 CFR 50.36 and the term " limiting safety system i setting" were developed. Although my dictionary has 80 some odd definitions of set or setting, I find that the use of the allowable !
value as a settin is not consistent with what I think of as an I instrument channe setting. That is, the instrument channel is set or 1 adjusted within its nominal setpoint range not its allowable value.
Additionally, the nominal setpoint is the only setting that is chosen {
such "that automatic protective action will correct the abnormal situation before a safety limit is exceeded" (10 CFR 50.36). W I
EELB R/F TDunning DISKfD0CUMENT NAME: G:\ SHARED \RG105REV JCalvo T* receive a copy of this document, Indicate in the boat 0 Thatcher "C" s Copy w/o attachment, "A" a Copy w/sttachment, "N" s No copy q
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DATE f/7/96 A i
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