ML20153F674
| ML20153F674 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/04/1988 |
| From: | NIAGARA MOHAWK POWER CORP. |
| To: | |
| Shared Package | |
| ML17055D838 | List: |
| References | |
| NUDOCS 8805110022 | |
| Download: ML20153F674 (7) | |
Text
__
- ~
,;g.
~%.,.
- *w%
(-
i-
., f'.
~
y$
TABLE 4.6.2a (Cont'd)
INSTRtMENTATION THAT INITIATES SCRAM 88 KrJ Surveillant.e Requirement ce
- oie oo jn88 Instrument-cn0*
Instrument Channel
'o Parameter Sensor Check Channel Test Calibration
'~
(8) Shutdown Position None Once during each None of Reactor Mode major refueling Switch outage (9) Neutron Flux (a) IRM (1) Upscale (f)
(f)
(f)
(ii)
Inoperative (f)
(f)
(f)
(b) APRM (1) Upscale None Once/ week Once/ week (m),
)
Once per 3 months j
(ii) Inoperative None Once/ week None j
(lit) Downscale None Once/ week Once/ week ").
I Once per 3 months (10) Turbine Stop None Once per 3 months Once per operating Valve Closure cycle (11) Generator Load None Once per month Once per 3 Rejection months i
a i
i 195
~. - - - -.-
~
NOTES FOR TABLES 3.6.2a and 4.6'.2a f
(a) May be bypassed when necessary for containment inerting.
~
~
(b) May be bypassed in the refuel and shutdown positions of the reactor mode switch with a keylock switch.
(c) May be bypassed in the refuel and startup positions of the reactor mode switch when reactor pressure is less than 600 psi.
(d) No more than one of the four IRM inputs to each trip system shall be bypassed.
(e) No more than two C or D level LPRM inputs to an APRM shall be bypassed and only four LPRM inputs to an APRM shall be bypassed in order for the APRM to be considered operable. No more than one of the four APRM inputs to each trip system shall be bypassed provided that the APRM in the other instrument channel in the same core quadrant is not bypassed. A Travelling In-Core Probe (TIP) chamber may be used as a substitute APRM input if the TIP is positioned in close proximity to the failed LPRM it is replacing.
(f) Calibrate prior to starting and normal shutdown and thereafter check once per shift and test once per week until no longer required.
(g)
IRM's are bypassed when APRM's are onscale. APRM downscale is bypassed when IRM's are onscale.
(h) Each of the four isolation valves has two limit switches.
Each limit switch provides input to one of two instrument channels in a single trip system.
(i) May be bypassed when reactor power level is below 451.
(j) Trip upon loss of oil pressure to the acceleration relay.
(k) May be bypassed when placing the reactor mode switch in the SHUTDOHN position and all control rods are fully inserted.
(1) Only the trip circuit will be calibrated and tested at the frequencies specified in Table 4.6.2a, the primary sensor will be calibrated and tested once per operating cycle.
(m) This calibration shall consist of the adjustment of the APRM channel to conform to the power values calculated by a heat balance during reactor operation when THERMAL POWER > 25% of RATED THERMAL POWER. Adjust the APRM channel if the absolute difference is greater than 21 of RATED THERMAL P0HER. Any APRM channel gain adjustment made in compliance with figure 2.1.1 shall not be included in determining the absolute difference.
196
?-
~
TABLE 3.6.29 (cont'd)
P INSTRlMENTATION THAT INITIATES CONTROL R00 NITHDRAHAL BLOCK Limiting Condition for Operation Minimum No. of Minimum No.
Operable Instrument Reactor Mode Switch of Tripped or Channels Per Position in Nhich Operable Operable Function Must Be Parameter Trip Systems Trip System Set Point Operable E
ct 4! 55 55
$ d?
c d5 SE u?
5E
- c. Downscale 2
3 (b) 2 5 percent of X
X full scale for each scale
- d. Upscale 2
3 (b)
< 88 percent of X
X full scale for each scale l
(3) APRM
(
- a. Inoperative 2 (h) 3 (c)
X X
X
- b. Upscale (Blased 2 (h) 3 (c)
Figure 2.1.1(h)
X X
X by Recirculation Flow)
- c. Downscale 2 (h) 3 (c) 2 2 percent of (d) (d)
.X full scale 217
TABLE 4.6.29 (Cont'd)
INSTRUMENTATION THAT INITIATES CONTROL ROD WITHORAHAL BLOC,Y Surveillance Requirement Instrument Instrument Channel Parameter Sensor Check Channel Test Calibration (3) APRM
- a. Inoperative None Once per month None
- b. Upscale (Blased None Once per month Once per 3 months by Recirculation Flow)
- c. Downscale None Once per month once per 3 months (4) Recirculation Flow
^
- a. Comparator None Once per month Once per month Off Normal
- b. Flow Unit None Once per month Once,per month Inoperative
- c. Flow Unit None Once per month Once per month Upscale 221
NOTES FOR TABLES 3.6.29 and 4.6.2q (a) No more than one of the four SRM inputs to the single trip system shall be bypassed.
(b) No more than one of the four IRM inputs to each instrument channel shall be bypassed.
These signals may be bypassed when the APRM's are onscale.
(c) No more than one of the four APRM inputs to each instrument channel shall be bypassed provided that the APRM in the other instrument channel in the same core quadrant is not bypassed. No more than two C or D level LPRM inputs to an APRM shall be bypassed and only four LPRM inputs to only one APRM shall be bypassed in order for the APRM to be considered operable.
In the Run mode of operation, bypass of two chambers from one radial core location in any one APRM shall cause that APRM to be considered inoperative. A Travelling In-Core Probe (TIP) chamber may be used as a subst'tute APRM input if the TIP is positioned in close proximity to the failed LPRM it is replacing.
If one APRM in a quadrant is bypassed and meets all requirements for operability with the exception of the requirement of at least one operable chamber at each radial location, it may be returned to service and the other APRM in that quadrant may be removed from service for test and/or calibration only if no control rod is withdrawn during the calibration and/or test.
(d) May be bypassed in the startup and refuel positions of the reactor mode switch when the IRM's are onscale.
(e)
This function may be bypassed when the count rate is > 100 cps.
(f) One sensor provides input to each of two instrument channels.
Each instrument channel is in a separate trip system.
(g) Calibrate prior to startup and normal shutdown and thereafter check once per shift and test once per week until no longer required.
(h) The actuation of either or both trip systems will result in a rod block.
223
t.
ATTACHMENT B NIAGARA H0 HAWK POWER CORPORATION NINE MILE POINT UNIT 1
~
LICENSE NO. DPR-63' DOCKET N0. 50-220 Supportino Information and No Stanificant HRzards Consideration Analysis The proposed Technical Specification amendment provides clarification of several requirements for APRM surveillance.
In Table 4.6.2a, a footnote has been added to point out the fact that the weekly instrument channel callbra-tion is being performed using built-in calibration equipment.
In addition, a surveillance requirement to perform a full instrument channel calibration of the APRH upscale and downscale settings once per three months was added to items (9)(b)(1) and (9)(b)(111) of Table 4.6.2a.
This change is to clarify that the weekly calibration of the APRM instruments currently identified in the Nine Mlle Point Unit 1 Technical Specifications is actually an adjustment of the APRM channel based on the power level calculated by a heat balance. A full instrument channel-calibration is performed once per three (3) months.
In Table 3.6.29, a footnote has been added to point out the fact that actuation of either of the two trip systems will cause a rod block.
Tables 4.6.2a (Item 9(b)(11)] and 4.6.2g [ Item 3(a)) are being revised to i
clarify that channel calibration is not applicable to the inoperative feature circuitry.
There is no setpoint associated with this feature.
There is an adjustment to the inoperative feature circuitry, which is performed as required during the quarterly calibration of APRM instrument channels.
However, for clarity this circultry adjustment should not be considered or identified as a channel calibration.
Therefore, "None" is being added to the instrument channel calibration column for the APRM inoperative parameter.
The proposed changes are merely clarifications of the current technical specifications.
The rewording is consistent with calibration practices at other plants and the standard technical specifications.
The proposed changes do not affect the frequency of calibration (surveillance) of the instruments.
Therefore, these changes are considered administrative in nature.
l The operation of Nine Mlle Point Unit 1. in accordance with the proposed amendment. will not involve a significant increase in the probability or consecuence of an accident previously evaluated.
These changes clarify present practices and design.
The proposed changes do not represent changes in established procedures.
Therefore, the proposed j
changes will not affect the probability or consequences of an accident.
4
)
4839G
r
~,
The operation of Nine Mile Point Unit 1, in accordance with the proposed amendment, will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed changes clarify present calibration practices and existing design.
The proposed changes will not change the method for performing the calibra-tions.
Therefore, no new or different kinds of accidents will be created.
_The operation of Nine Mlle Point Unit 1, in accordance with the proposed amendment, will not involve a significant reduction in a margin of safety.
The proposed changes do not affect operations or change the frequency of calibration (surveillance).
Therefore, there is no reduction in a margin of safety.
4839G