ML18093B241

Proposed Tech Specs,Reducing Correction for Flow Measurement Uncertainty from 3.5 to 2.2%

ML18093B241
Person / Time
Site:	Salem
Issue date:	10/19/1988
From:	Public Service Enterprise Group
To:
Shared Package
ML18093B240	List: ML18093B239 ML18093B241
References
NUDOCS 8810260306
Download: ML18093B241 (6)

Text

ENCLOSURE 4 SALEM UNIT NO. 2 REVISED TECHNICAL SPECIFICATION PAGES r - - - - - -- -- --

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POWER DISTRIBUTIO 3/4.2.3 RCS FLOW RATE AND R LIMITING CONDITION FOR OPERATION

• 3.2.3 The combination of indicated Reactor Coolant System (RCS) total flow rate and R , R shall be maintained within the region of allowable operation 1 2 shown on Figure 3.2-3 for 4 loop operation.

where:

N

a. Rl = FAH 1.49 [1.0 + 0.3 (1.0-P)]

b. = Rl R2

[1-RBP(BU)]

c. p = THERMAL POWER and RATED THERMAL POWER N

d. FAH = Measured values of F~ obtained by using the movable incore detectors to o~ta~n a power distribution map.

The measured values of FAH shall be used to calculate R since Figure 3.2-3 includes measurement uncertainties ofN2.2% for flow and 4% for incore measurement of FAH"

e. RBP(BU) = Rod Bow Penalty as a function of region average burnup as shown in Figure 3.2-4, where a region is defined as those assemblies with the same loading date (reloads) or enrichment (first core).

APPLICABILITY: MODE 1 ACTION:

With the combination of RCS total flow rate and R , R outside the region of 1 2 acceptable operation shown on Figure 3.2-3:

a. Within 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s:

1. Either restore the combination of RCS total flow rate and R ,

1 R to within the above limits, or 2

2. Reduce THERMAL POWER to less than 50% of RATED THERMAL POWER and reduce the Power Range Neutron Flux - High trip setpoint to less than or equal to 55% of RATED THERMAL POWER within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

SALEM - UNIT 2 3/4 2-9 Amendment No. 20

POWER DISTRIBUTIO LIMITING CONDITION FOR OPERATION b.

• Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of initially being outside the above limits, verify through incore flux mapping and RCS total flow rate comparison that the combination of R , R and RCS total flow rate are restored to 1

within the above limits, 2 or reduce THERMAL POWER to less than 5% of RATED THERMAL POWER within the next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

c. Identify and correct the cause of the out-of-limit condition prior to increasing THERMAL POWER above the reduced THERMAL POWER limit required by ACTION items a.2 and/orb., above; subsequent POWER OPERATION may proceed provided that the combination of R , R and 2

indicated RCS total flow rate are demonstrated, through 1incore flux mapping and RCS total flow rate comparison, to be within the region of acceptable operation shown on Figure 3.2-3 prior to exceeding the following THERMAL POWER levels:

1. A nominal 50% of RATED THERMAL POWER,

2. A nominal 75% of RATED THERMAL POWER, and

3. Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of attaining greater than or equal to 95% of RATED THERMAL POWER.

SURVEILLANCE REQUIREMENTS 4.2.3.1 The provisions of Specification 4.0.4 are not applicable.

4.2.3.2 The combination of indicated RCS total flow rate and R , R shall be 1 2 determined to be within the region of acceptable operation of Figure 3.2-3:

a. Prior to operation above 75% of RATED THERMAL POWER after each fuel loading, and

b. At least once per 31 Effective Full Power Days.

4.2.3.3 The indicated RCS total flow rate shall be verified to be within the region of acceptable operation of Figure 3.2-3 at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> when th~ values of R and R obtained per Specification 4.2.3.2 are assumed to 1 2 exist.

4.2.3.4 The RCS total flow rate indicators shall be subjected to a CHANNEL CALIBRATION at least once per 18 months.

4.2.3.5 The RCS total flow rate shall be determined by measurement at least once per 18 months.

SALEM - UNIT 2 3/4 2-10

4: {-' .Y

• FIGURE 3.2-3 RCS TOTAL FLOWRATE VERSUS R-FOUR LOOPS IN OPERATION

...

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MEASUREMENT _.

ACCEPTABLE DPERATIDNI --iI

• --

UNCERTAINTIES

~

REt;IDN FDR

46. OF' 2.2!1C FOR FLOW R2 ONLY ~1 ANO 4" FOR INCORE

~EASUREMENT OF

- F L\HARE INCLUDED IN THIS FIGURE

...

44.*-

- UNACCEPTABLE OPERATION

-

2

~ 42.

...

-

• - REGIDN ---

LtQ ACCEPTABLE OPERATION REGION FOR

• -- R1 AND R2

,.j (1.039,39.4:

-

• - ,j

,J -

36.

• -- ..j (1.0,35.7) 34.

• --0.90 0.95 1.00 1.05 1.10 R1 = F f!K/1.49(1.0+0.3(1.0 - P)]

R2 ""' R1 /[1 - RBP(BU)]

SA:LEMi - UNIT 2 3/4 2-11 Amendment No.

• __ ...'.--;;: - -,- - - J' POWER DISTRIBUTIO~MITS BASES 3/4.2.2 and 3/4.2.3 HEAT FLUX HOT CHANNEL FACTOR FQ(Z), RCS FLOW RATE AND NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR The limits on heat flux and nuclear enthalpy hot channel factors and RCS flow rate ensure that 1) the design limits on peak local power density and minimum DNBR are not exceeded and 2) in the event of a LOCA the peak fuel clad temperature will not exceed the 2200°F EGGS acceptance criteria limit.

Each of these is measurable but will normally only be determined periodically as specified in Specifications 4.2.2 and 4.2.3. This periodic surveillance is sufficient to insure that the limits are maintained provided:

a. Control rod in a single group move together with no individual rod insertion differing by more than +/- 12 steps from the group demand position.

b. Control rod groups are sequenced with overlapping groups as described in Specification 3.1.3.5.

c. The control rod insertion limits of Specifications 3.1.3.4 and 3.1.3.5 are maintained.

d. The axial power distribution, expressed in terms of AXIAL FLUX DIFFERENCE, is maintained within the limits.

F~H will be maintained within its limits provided conditions a. thr~ugh d., above, are maintained. As noted in Figure 3.2-3, RCS flow rate and FAH may be "traded off" against ~ne another (i.e., a low measured RCS flow rat:e is acceptable if the measured FAH is also low) to ensure that the cakculated DNBR will not be below the design DNBR value. The relaxation of FAH as a function of THERMAL POWER allows changes in the radial power shape ror all permissible rod insertion limits.

N RJ, as calculated in 3.2.3 and used in Figure 3.2-3, accounts for FAH less tfian or eq~l to 1.49. This value is used in the various accident analyses where FAH_ influences parameters other than DNBR, e.g., peak clad temperature, and tnus is the maximum "as measured" value allowed. R , as defined, allows for the inclusion of N 2 penalty for rod bow on DNBR only, thus knowing the "as measured" values of FAH and RCS flow allows for "tradeoffs" in excess of R equal to 1.0 for the purpose of offsetting the rod bow DNBR penalty.

Fuel rod bowing reduces the value of DNB ratio. Sufficient credit is available to offset this reduction. This credit comes from generic design margins totaling 9.1% and 3% margin in the difference between the 1.3 DNBR safety limit and the minimum DNBR calculated for the Complete Loss of Flow SALEM - UNIT 2 B 3/4 2-4

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!---*----*- -_--~ --. ~- POWER DISTRIBUTIOe I MITS BASES 3/4.2.2 and 3/4.2.3 HEAT FLUX HOT CHANNEL FACTOR F (z), RCS FLOW RATE AND NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR (Continued 9 event. The penalties applied to F~H to account for Rod Bow (Figure 3.2-4) as a function of burnup are consistent with those described in Mr. John F. Stolz's (NRC) letter to T. M. Anderson (Westinghouse) dated April 5, 1979 and W 8691 Rev. 1 (partial rod bow test data).

When an F measurement is taken, an allowance for both experimental error and manufactur~ng tolerance must be made. An allowance of 5% is appropriate for a full core map taken with the incore detector flux mapping system and a 3% al~owance is appropriate for manufacturing tolerance. When RCS flow rate and F li are measured, no additional allowances are necessary prior to 8

comparison with the limits of Figure 3.2-3. Figure 3.2-3 isNadjusted to allow for a 2.2% error in RCS Flow rate and a 4% error in F H. The 8

correction for RCS flow was reduced as a result of the replacement of the RTD Bypass Loops with thermowell RTDs. The detailed justification for the reduction is contained in WCAP-11579 (Proprietary) dated September 1987.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period surveillance of indicated RCS flow is sufficient to detect only flow degradation which could lead to operation outside the acceptable region of operation shown in Figure 3.2-3.

The radial peaking factor F (Z) is measured periodically to provide assurance that the hot channel factoR~~FQ(Z), remains within its limit. The F limit for RATED THERMAL POWER (F ), as provided in the Radial Peaking Fa~tor Limit Report per specification 6~~.1.10, was determined from expected power control maneuvers over the full range of burnup conditions in the core.

3/4.2.4 QUADRANT POWER TILT RATIO The quadrant power tilt ratio limit assures that the radial power distribution satisfies the design values used in the power capability analysis. Radial power distribution measurements are made during startup testing and periodically during power operation.

SALEM - UNIT 2 B 3/4 2-5 Amendment No.