ML20206S609

Proposed Tech Spec,Substituting Requirement to Measure source-range Neutron Flux Instrumentation High Voltage Plateau W/Discriminator Bias Curves

ML20206S609
Person / Time
Site:	Byron, 05000000
Issue date:	09/15/1986
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20206S605	List: ML20206S601 ML20206S609
References
2100K, NUDOCS 8609220285
Download: ML20206S609 (6)

Text

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ATTACISIENT 1 PROPOSED CHANGE TO APPENDIX A TECHNICAL SPECIFICATIONS FOR BYRON STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NPF-37 Revised Page: 3/4 3-9 3/4 3-12

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TABLE 4.3-1 h REACTOR TRIP SYSTEN INSTRUNENTATION SURVEILLANCE REQUIRENENTS E

, TRIP c ANALOG ACTUATING. H0 DES FOR

$ CHANNEL DEVICE WillCN d CHANNEL CilANNEL OPERATIONAL OPERATIONAL ACTUATION SURVEILLANCE g FUNCTIONAL UNIT CilECK CALIBRATION TEST TEST LOGIC TEST IS REQUIRED

! b1. Manual Reactor Trip N.A. N.A. H.A. R H.A. 1, 2, 3*, 4*, 5*

j 2. Power Range, Neutron Flux I

a. liigh Setpoint S D(2, 4), Q H.A. N.A. 1, 2 M(3, 4),

Q(4, 6),

R(4, '

l b. Low Setpoint S R(4)g5% Q N.A. N.A. 1###, 2 i w

) 3. Power Range, Neutron Flux, N.A. R(4) Q N.A. N.A. 1, 2 o Nigh Positive Rate E

l 4. Power Range, Neutron Flux, N.A. R(4) Q N.A. N.A. 1, 2 liigh Negative Rate 5

5. Intermediate Range, S R(4,h)4 Q H.A. M.A. 1###, 2 Neutron Flux

6. Source Range, Neutrdn Flux 5 R(4, [ 12) Q(9) N.A. N.A. 2##, 3, 4, 5 l 7. Overtemperature AT S R(13) Q N. A'. N.A. 1, 2

8. Overpower AT S R Q N.A. N.A. 1, 2

9. Pressurizer Pressure-Low S R ,

Q** N.A. N.A. 1 l (Above P-7)

10. Pressurizer Pressure-Nigh S R Q N.A. N.A. 1, 2

11. Pressurizer Water Level-Nigh S R Q N.A. N.A. 1 (Above P-7)

TABLE 4.3-1 (Continutd) s TABLE NOTATIONS 4

• With the Reactor Trip System breakers closed and the Control Rod Drive System capable of rod withdrawal.

• • These channels also provide inputs to ESFAS. The Operational Test Frequency-for these channels in Table 4.3-2 is more conservative and, there. fore, controlling.

MBelow P-6 (Intermediate Range Neutron Flux Interlock) Setpoint.

1. NBelow P-10 (Low Setpoint Power Range Neutron Flux Interlock) Setpoint.

(1) If not performe,d in previous 7 days.

(2) Comparison of calorimetric to excore power indication above 15% of RATED THERMAL POWER. Adjust excore channel gains consistent with calorimetric power if absolute difference is greater than 2%. The provisions of Speci-fication 4.0.4 are not applicable for entry into MODE 2 or 1.

(3) Single point comparison of incore to excore AXIAL FLUX DIFFERENCE above 15% of RATED THERMAL POWER. Recalibrate if the absolute difference is greater than or equal to 3%. The provisions of Specification 4.0.4 are not applicable for entry into MODE 2 or 1. '

(4) Neutron detectors may be excluded from CHANNEL CALIBRATION.

(5od Initial plateau curves shall be measured for each detector. Subsequent plateau curves shall be obtained, evaluated and compared to the initial

. curves. For the Intermediate Range and Power Range Neutron Flux channels

( the provisions of Specification 4.0.4 are not applicable for entry into MODE 2 or 1. ,

(6) Incore - Excore Calibration, above 75% of RATED THERMAL POWER. The provi-sions of Specification 4.0.4 are not applicable for entry into MODE 2 or 1.

(7) Each train shall be tested at least every 62 days on a STAGGERED TEST BASIS.

(8) With power greater than or equal to the interlock Setpoint the required ANALOG CHANNEL OPERATIONAL TEST shall consist of verifying that the inter-lock is in the required state by' observing thE permissive annunciator window.

(9) Surveillance in MODES 3*, 4*, and 5* shall also include verification that permissives P-6 and P-10 are in their required state for existing plant conditions by observation of the permissive annunciator window. Surveil-lance shall include verification of the Baron Oilution Alarm Setpoint of less than oi equal to an increase of twice the count rate within a 10-minute period.

(10) Setpoint verification is not applicable.

(11) At least once per 18 months and following maintenance or adjustment of the Reactor trip breakers, the TRIP ACTUATING DEVICE OPERATIONAL TEST shall include independent verifiqation of the Undervoltage and Shunt trips.

(12) At least once per 18 months during shutdown verify that on a simulated Baron Dilutien Doubling test signal CVCS valves 1120 and E open and 1128 and C close within 30 seconds.

(13(CHANNEL CALIBRATION shall include the RTD bypass loops flow rate.

- (5tV WA ve. hi A 3 voltase. se%3varisal as recommended by ihe manu6ckeg as initial discrimW bias curve shall be m ensu fior e och defedor .

Sphe*9usat discrim;nder tes curvss shall be obbin evoluaied oad coryared BYRON - UNITS 1 & 2 3/4 3-12 fo, 4 he irw,,Mt curves.

ATTACISBNT 2 SUfeULRY OF CHANGRS Five (5) changes to the Byron Station Technical Specifications have been identified. These changes are also applicable to Braidwood and are listed below:

1) Page 3/4 3-9, Table 4.3-1, Reactor Trip System Instrumentation Surveillance Requirements (a) Item 2.a, High Setpoint Change Channel Calibration, change R(4,5) to R(4,5a)

(b) Item 5, Intermediate Range, Neutron Flux Change Channel Calibration, change R(4,5) to R(4,5a)

(c) Item 6, Source Range, Neutron Flux Change Channel Calibration, change R(4,5) to R(4,5b,12).

2) Page 3/4 3-12, Table Notations (for Table 4.3.1)

(a) Change Item #5 to Sa.

(b) Following Item Sa, insert a new table notation, item 5b, which reads as follows:

"5b. With the high voltage setting varied as recommended by the manufacturer, an initial discriminator bias curve shall be measured for each detector. Subsequent discriminator bias curves shall be obtained, evaluated and compared to the initial curves."

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ATTACISBNT 3' EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION REACTOR TRIP SYSTEM INSTRUMENTATION SL*RVEILLANCE RBOUIREMENTS (3/4 3-9 & 3-12)

DESCRIPTION OF AMENDMENT REQUEST The requested change involves substituting the requirement to measure the source range neutron flux instrumentation high voltage plateau j curve with source range neutron flux instrumentation discriminator bias curves.

i This change is requested based upon the Westinghouse low-noise pre-amplifier source range alignment procedure which does not require obtaining high voltage plateau curves as a part of the alignment procedure.

Instead, a discriminator bias curve is required to be obtained and is used to demonstrate degradation of the source range detectors, if any occurs.

Currently, Byron Station obtains plateau curves to satisfy the existing Technical Specifications'as well as the vendor recommendations. Therefore, the proposed revision will be consistent with the vendor's recommendation.

This proposed Technical Specification change is also applicable to Braidwood Units 1 and 2 and should be included in the Braidwood Technical Specifications.

Basis for No Significant Hazards Determination commonwealth Edison has evaluated this proposed amendment and determined that it involves no significant hazards considerations. In accordance with the criteria of 10 CFR 50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:

1) Involve a significant increase in the probability or consequences of an

accident preivously evaluated because:

l l (a) the functions of the source range neutron flux instrumentation j are not being changed or degraded as a result of this Technical

Specification revision. We are merely incorporating the vendor

( recommendations of obtaining data which can be used to determine l potential source range detector degradation. Therefore, the probability or consequences of previously evaluated accidents are i unaltered.

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2) Create the possibility of a new or different kind of accident from any accident previously evaluated because:

(a) the revision to the Technical Specification does not change any of the operational characteristics of the source range neutron flux instrumentation, or the manner that the system is operated. Hence, the possibility of a new or different kind of accident being created than previously evaluated is unchanged.

3) Involve a significant reduction in the margin of safety because:

(a) there are no changes being made to hardware, or in the manner that the system is being operated. The automatic actions, response times, setpoints and alarms of the source range neutron flux instrumentation are not affected by this technical specification revision. Therefore, the margin of safety is not being compromised as a result of this proposed license amendment.

Therefore, since the proposed license amendment satisfies the criteria specified in 10 CFR 50.92. Commonwealth Edison has determined that a no significant hazards consideration exists for this item and requests its approval in accordance with the provisions of 10 CFR 50.91(a)(4).

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