ML20024H092
| ML20024H092 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 04/22/1991 |
| From: | Kovach T COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 NUDOCS 9105210262 | |
| Download: ML20024H092 (3) | |
Text
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N Ccmmonwealth Edison
/ 1400 opus Place
.A 1
C Downers Grove, Illinoi6 00516 April 22,1991 Mr. A. Bert D:tvis Regional Administrator U.S. Nuclear Regulatory Commission 799 Roosevelt Road Rill Glen Ellyn, il 60137
Subject:
Zion Station Units 1 and 2 Response to inspection Repori Nos. 50 295/90032 and 50 304/90032 NRO Docket Noo,50 295 and 50-304.
Reference:
(a) March 1,1991 letter from M.A. Ring to Cordell Reed (b) August 24,1987 letter from P.C. LeBlond to U.S. NRC -
(c) April 15,1991 lotter from S.F. Stimac to T.E. Murley
Dear Mr. Davls:
The letter of Reference (a) provided the results of a special safety inspection of the activities at Zion Station Units 1 and 2 on November 26 30,1990. The letter indicated that certain Regulatory Guide (RG) 1.07 activities appeared to be a deviation from commitments previously made to NRC by Commonwealth Edison Company (CECO). The CECO response to the Notice of Deviation is provided in the enclosure.
In a telephone discussion on March 25,1991 with Mr. M.A. Ring, CECO requested an extension for this response. At that time an extension until April 22,1991 was granted.
Please direct any questions regarding this response to this office.
Sincerely, pp T.J.[,vach o
Nuclear Licensing Manager Enclosure cc:
NRC Document Control Desk C. Patel NRR J. Smith-Zion APR 2 4 D91 1,y ',/scl:lD725:12 8o" 9105210262 910422 y '\\ l 4,5
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ENCLOSURE COMMONWEALTH EDISON COMPANY RESPONSE TO li4 SPEC'llON REPORT e
F NOS,50-295/90032 & 50-304/90032 i
1 P
l Deviation (295/90032 OLND)
"The following examples identify a deviation to your commitment to com aly with Regulatory Guide (RG) 1.97, Revicion 2. This deviation was identified c uring an inspection conducted from November 26 30,1990.
a.
RG 1.97, Revision 2, sechon C, paragraph 1.3.1.b, states that no single failure within the accident monitoring instrumentation or its power sources should prevent the operators from being presented Category 1 Information.
Contrary to the above, the reactor coolant system wide range pressure 1
recorder PR 403 does not meet the single failure requirements of RG 1.97 (50 295/90032 01 A(DRS); 50 304/90032 01 A(DRS)).
b.
RG 1.97, Revision 2, section C, paragraph 1.6, states that the Instrument ranges specified in Table 2 should be considered the minimum ranges for accident monitoring instrumentation.
Contrary lo the above, the steam Generator wide range level, steam generator narrow range level, pressurizer level, and steam line pressure instrumentation did not meet the rninimum ranges specified in Table 2 i
(50 295/90032 01B(DRS): 50 304/90032-01B(DRS)).*
Reasortfotthe_Deylation -
a.
A malfunction internal to the pressure recorder or loss of power supply to the recorder were not recognized as single f ailure vulnerabilities during the initial RG 1.97 review. Therefore, the reactor coolant wide range pressure variable was incorrectly identified as complying with RG 1,97 in the 1987 submittal (Reference (b)).
b.
At the time of the 1987 submittal, CECO considered the steam generator and pressurizer level ranges provided to be adequate and in compliance with the RG because the ranges specified in the RG were considered to be generically written to convey the intent of the RG, not to prescribe e
requirements for the exact locations of level taps. The deviation between the RG specified range and the existing range for steam line pressure was identified in Note 21 of the original table (70% above full power steam pressure vs. 20% above lowest safety valve setting). However, the existing range reported in the table mistakenly corresponded to the overall transmitter ranDe instead of the calibrated / Indicated range,
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ENCLOSURE (continuwf)
Corrective ActionTaken and.Results Achieved; a.
Subsequent to the 1987 RG 1.97 submittal, the Core Exit Thermocouple /Subcooling Margin Monitor (CET/SMM) system was upgraded. This system recolves input from both RCS wide range pressure loops (403 and 405)he o3erator can display both channels of RCS wide.
recorder PR 403. T range pressure on the C ET/SMM display. A loss of power to, or internal malfunction of, PR 403 will not arovent the operator from being presented with RCS wide range pressure nformation, b.
Updated RG 1.97 compliance tables have been repared and were submitted to the NRC on 4/15/91 (Reference (c. During the preparation of these tables, a detailed review of the level Indic tions and steam iine pressure indications was performed. Deviations from the ranges specified in the RG were explained and jastified in notes to the updated tables.
Commor. wealth Edison considers the ranges specified in the updated tables to be consistent with the intent of RG 1.97.
Correcth a Actions _toAvoldfurther_Doylat!ons:
a&b.
Updated RG 1.97 compliance tables have been prepared and were submitted to the NRC on 4/15/91 (Reference (c)). During the preparation of these tables, common mode f ailure of recorders serving more than one Instrument loop were specifically evaluated to determine if the failure of the recorder would prevent the operator from being presented with Category 1 information. The updated tables also include clarification and/or lustification for instrument ranges that do nnt meet the literal Interpretation of RG 1.97.
Date_When_ Corrective Actions _Will Be Corapleted:
a & b.
All corrective actions and corrective actions to avoid further deviations have been completed, l
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