ML20138H669
| ML20138H669 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 12/04/1985 |
| From: | Tucker H DUKE POWER CO. |
| To: | Harold Denton, Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8512170275 | |
| Download: ML20138H669 (4) | |
Text
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DUKE POWER Go>mtxy P.O. DOX 33180 CHARLOTTE, N.C. 28242 HAL H. TUCKER TELEPHONE vice ear. ardent (704) 373-4531 wtts.aAB PRODtt0 TION
-/
December 4, 1985
'Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.
S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. B. J.
Youngblood, Project' Director PWR Project. Directorate No. 4 Re:
Catawba Nuclear Station Docket Nos. 50-413 and 50-414 Technical Specifications
Dear Mr. Denton~:
In response to the December 2, 1985 telephone conference call between Mr. Roger Ouellette and members of your staff, provided is additional information with respect to the changes' proposed to Technical Specification Table 3.2-1, "DNB Parameters".
The two attached Technical Specification pages were submitted in a letter from Mr.
H.
B. Tucker to Mr.
H.
R.' Denton dated November 8, 1985.
The proposed changes were calculated using an analysis taking into account channel accuracies, indicator display (control room meter or computer display) and the. number of operable channels feeding.
the display mechanism.
The meter readings are read off of control room gauges for these parameters.
The computer display refers to the display read off of the' Operator Aid Computer.
Accordingly, an appropriate' readability uncertainty was added to the meter displayed parameters.
This analysis used the Westinghouse Setpoint Methodology to calculate the appropriate limits taking into account Catawba specific safety analysis assumptions'and-instrumentation / indication uncertainties.
'The channel accuracies were taken directly from the Westinghouse Setpoint Methodology For Protection Systems, Catawba Station, June 1984.
This document was transmitted to the'NRC via a July 30, 1984 letter.
Included in the calculations were uncertainties associated l
with the display mechanisms (i.e. calibration and readability.of.
the meters).
These additional uncertainties are necessary since Pwn - A/BC's TECH SUPPORT
PDR ass inauscra)
FOR (BENAF0YA)
Mr.- Harold R.:Denton, Director
. December 4, 1985 Page Two the Technical Specification DNB parameter limits are " indicated" measurements to be read.from the gauges or the computer display.
The proposed changes to the values in Table 3.2-1 were derived in accordance with the safety analysis assumptions and include instrumentation' uncertainties given in the Westinghouse Setpoint Methodology for Catawba and actual indication uncertainties present at the plant.
Therefore, these proposed changes do not:
(1)
Involve a significant increase in the probability or consequences of an accident previously evaluated since the original accident analyses assumptions were used to calculate these parameters; (2)
Create the-possibility of a new or different kind of accident from any accident previously evaluated because the operation of the plant is still bounded by the original accident analysis; or (3)
Involve a significant reduction in a margin of safety since the new values were derived using the same accident analysis assumptions that were used originally.
The new numbers are the result of a new analysis based upon the Catawba specific setpoint study but take into account the-plant specific uncertainties associated with the
" indicated" parameters and the possibility of one inoperable channel per indicator.
Very truly yours, c
Hal B. Tucker RWO:slb Enclosure cc:
Dr.'J. Nelson Grace, Regional Administrator U. S. Nuclear-Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta,. Georgia. 30323 NRC Resident Inspector Catawba Nuclear Station
PROOF & REVIEW dopy TA8tE 3.2-1 DNS PARAMETERS PARAMETER i
LIMITS Four Loops in Operation '
~Averace Temperature Meter average
- 4 channels: < 592*F
- 3 channels: 5592*F Computer average
- 4 channels: '< 593*F
- 3 channels: 5593*F Pressurizer Pressure.
7 deter average
- 4 channels: > 2225s( psig*
- 3 channels: 12230 psig*
Computer average
- 4 channels: 1 222f psig*
- 3 channels: 1 2224 psig*
- Limit not applicable during either a THERMAL POWER ramp in excess of 5% of RATED THERMAL POWER per minute or a THERMAL POWER step in excess of 10% of RATED THERMAL POWER.
OCT 7 1985 CATAWBA - UNITS 1 AND 2 3/4 2'18
PROOF & REYlEW COPY
_ POWER DISTRIBUTION LIMITS 8ASES 7
QUADRANT POWER TILT RATIO (Continued) flux map or two sets of four symmetric thimbles.
thimbles is a unique set of eight detector locations.The two sets of four symmetric The normal locations are C-8, E-5, E-11, H-3, H-13, L-5, L-11, N-8.
Alternate locations are available if any of the normal locations are unavailable.
3/4.2.5 DN8 PARAMETERS The limits on the DNS-related parameters assure that each of tid parameters are maintained within the normal steady-state envelope of operation assumed in
.the. transient and accident analyses.
The limits are consistent with the initial FSAR assumptions and have been analytically demonstrated adequate to maintain a design limit DN8R throughout each analyzed transient.
The indicated T,yg value N and the indicated pressurizer pressure value6 corre-spond to analytical limits of 594.8*F and psig respectively, with allow-ance for measurement uncertainty.
2.tos.s The 12-hour periodic surveillance of these parameter? through instrument readout is sufficient to ensure that the parameters are reitored within their limits following load changes and'other expected transient operation. Measure-ment uncertainties must be accounted for during the periodic surveillance.
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l CATAWBA - UNITS 1 AND 2 8 3/4 2-6
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