ML20134N099
| ML20134N099 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 08/28/1985 |
| From: | Massin H COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20134N100 | List: |
| References | |
| 0564K, 564K, NUDOCS 8509050004 | |
| Download: ML20134N099 (5) | |
Text
7....
~ [ 'N Commonwealth Edison l
/ One First Nitionit Pitze. Chictgo, Ilhnois i
7
'I Address Reply to. Post Office Box 767 (j Chicago, Illinois 60690 j
August 28, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
LaSalle County Station Units 1 and 2 Proposed Amendments to Technical Specification for Facility Operating License W F-ll and W F-18 APRM Calibration Gain Adjustment Factors WC Docket Nos. 50-373 and 50-374 References (a): Technical Specification 3.2.2.
(b): Technical Specification 3.3.1.
(c): UFSAR Table 15.0-1.
(d): NUREG-0123, Revision 3.
BWR/5 Standard Technical Specifications.
Dear Mr. Denton:
Pursuant to 10 CFR 50.59, Commonwealth Edison proposes to amend Appendix A, Technical Specification, to Facility Operating License NPF-11 and NPF-18. This amendment change is being submitted for your staff's review and approval.
This proposed amendment addresses allowable APRM gain adjustment factors and clarifies the wording of two additional specifications.
Attachment A provides background and discussion. The proposed change is enclosed in Attachment B.
The attached change has received both On-Site and Off-Site review and approval. We have reviewed this amendment request and find that no significant hazards consideration exists. Our review is documented in Attachment C.
Commonwealth Edison is notifying the State of Illinois of our request for this amendment by transmitting a copy of this letter and its attachments to the designated State Official, yf 8509050004 B g 373 PDR ADOCK O PDR f160#
P QcN[ W g Ool'$7h
1 d
'H. R. Denton August 28, 1985 In accordance with the requirements of 10 CFR 50.170, a fee remittance in the amount of $150.00 is enclosed.
Please direct any questions you may have concerning this matter to this office.
'Three (3) signed originals and thirty-seven (37) copies of this transmittal and its attachments are provided for your use.
Very truly yours, h%)
H. L. Massin Nuclear Licensing Administrator j
j 1m i
i t
Attachments A: Background and Discussion B: Technical Specification Change to W F-ll and W F-18 C: Evaluation of Significant Hazards Consideration 4
cc: Region III Inspector - LSCS A. Bournia - NRR M. Parker - State of Ill SUBSCR 0 AND.
RN to
@1985 befor Jme_ this day
-of flLd YA.d
.M A
l Notary Public 4
f l
0564K i
i b
4 r
4
ATTACHMENT A TECHNICAL SPECIFICATION CHANGE REQUEST LASALLE COUNTY STATION UNITS 1 and 2
SUBJECT:
LaSalle County Station Units 1 and 2 APRM Calibration Gain Adjustment Factors BACKGROUND Questions have arisen concerning the interpretation and intention of footnote d of Table 4.3.1.1-1 (RPS Instrumentation Surveillance Requirements) which ppplies to the weekly calibration of the average power range monitors (APRMs). The footnote specifies that during the calibration, the absolute difference between the APRMs and real power as determined by a heat balance should not be ;> 2% (ie. APRM Gain Adjustment Factor (GAF) of between 0.98-1.02) during operational condition 1 when thermal power is 2 25%, unless a peaking factor exists which dictates the GAFs to be set conservatively to satisfy Technical Specification 3.2.2. (Reference (b))
A situation occurred recently where the APRM GAFs for one RPS trip system were the following:
---one APRM GAF was non-conservative (>1.02),
---one APRM GAF was within specification (between.98-1.02),
---one APRM GAF was conservative (<.98).
It appeared that two of the APRMs in the trip channel were inoperable (those with GAFs not between 0.98-1.02), and if the APRMs could not be adjusted within one hour, a half-scram would be required per action a of specification 3.3.1. (Reference (b)) This interpretation seems to be too conservative, and is not the intent of this specification. APRM channels with conservative GAFs (<.98) should not be declared inoperable.
DISCUSSION Since the Technical Specification on APRM GAFs does not appear to be clearly specified, this amendment is submitted to clarify this issue.
This proposal more clearly states what is believed to be the intention of the current specifications.
During power operation atit 90% rated thermal power:
-- APRM GAFs should not exceed 1.02 or be less than 0.98.
-- If an APRM in a trip system has a GAF which exceeds 1.02, 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> should be allowed to correct the situation prior to declaring the channel inoperable. Declaring a che.nnel inoperable does not mean the APRM needs to be bypassed.
. If an APRM has a GAF which is less than 0.98,12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> should be allowed to correct the situation prior to declaring the channel inoperable.
Until corrective action is taken, a notification of the conservative GAF should be posted on the reactor control panel.
During power operation at 6 90% rated thermal power:
--APRM GAFs should not exceed 1.02.
However, the GAFs may be set conservatively, provided the gain adjustment increment does not exceed 10% of rated thermal power.
--If an APRM in a trip channel has a GAF which exceeds 1.02, 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> should be allowed to correct the situation prior to declaring the channel inoperable. Once again, declaring a channel inoperable does not mean the APRM has to be bypassed.
--If an APRM exceeds the heat balance power level by greater than 10% of rated thermal power, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> should be allowed to correct the situation prior to declaring the channel inoperable.
-Anytime an APRM GAF is less than 0.98, a notification of the conservative GAF should be posted on the reactor control panel.
There are two concerns with regards to the APRM value difference from the real power as calculated from a heat balance.
The most important concern is when the APRMs indicate a power below the heat balance power (GAF > l.0).
This is the non-conservative case. A difference of up to 2% is analyzed (reference (c)) and allowed by the present footnote. This applies during all plant power levels above 25%
RATED THERMAL POWER. If the APRM calibration does not meet this requirement, the footnote needs a time limit to restore the channel calibration before declaring the channel inoperable. Guidance is given by reference (a) and footnote ( A) to Table 3.3.1.
This would allow 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to restore the nonconservative GAF prior to declaring the channel inoperable.
The other concern exists when the APRMs indicate a power greater than the heat balance power (GAF 4 1.0).
This concern is of lesser importance in that the APRM trip setpoints are conservative, however, the indicated power is higher than real power. Again guidance is provided in other specifications. Reference (a) allows the APRM to read high up to 90% power provided the APRM reading does not exceed 100% of RATED TERMAL POWER and the gain adjustment increment does not exceed 10% of RATED THERMAL POWER. This allowance should also apply to reference (b). Above 90% of RATED THERMAL POWER the existing limit of 2% should apply (GAF2 0.98). However, since the high reading APRM channel (s) is an indication problem only, a longer time should be allowed to restore the indication to within the required range. A time period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is a reasonable period to restore a conservative GAF prior to declaring the channel inoperable. Footnote (d) to Table 4.3.1.1-1 is revised in this proposed amendment to incorporate the above discussion.
. Action a of Specification 3.3.1 and NOTE (a) of Table 3.3.1-1 are also updated in this amendment. These changes are required to clarify that for trip systems which have more than two channels per trip system, it is acceptable to trip the inoperable channel or channels and not necessary to place the trip system in the tripped condition. With a design which has 4 channels and requires more than one channel to trip to cause the trip function to occur, the present wording can be construed to mean the entire trip system must be tripped when one of the channels is inoperable.
However, if the inoperable channel is placed in the tripped condition no loss of safety function has occured and if a second operable channel trips the trip function will occur as required. This change is merely a i
clarification of the wording of the action required and is in accordance with reference (d).
Also the footnote
- to specification 3.2.2 is revised to delete the words "during power ascension". While this footnote is generally only used during power ascension, there are occasions when it may need to be used when reducing power as well.
0564K 1
. -