Text

Forwards Revised Proposed Changes to Tech Specs Re New Limits for Radial Peaking Factors & Allowable Linear Heat Rates & Identifying Use of ex-core Detectors for Core Power Distribution Monitoring.Requests Approval by 811208 Restart
	ML18046B098
Person / Time
Site:	Palisades
Issue date:	11/20/1981
From:	Hoffman D; CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Crutchfield D; Office of Nuclear Reactor Regulation
References
	NUDOCS 8111270140
	Download: ML18046B098 (33)
	v • d • e

~

' *. J. ~-

I consumers Power company General Offices:

1945 West Parnell Road, Jackson, Ml 49201 * (517) 788-1636 November 20~ 1981 Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief Operating Reactors Branch No 5 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR David P Hoffman Nuclear Lice11si11g /dmi1'istr.:itor PALISADES PLANT - REVISED TECHNICAL SPECIFICATION CHANGE REQUEST -

LINEAR HEAT RATE LIMITS, RADIAL PEAKING FACTORS, AND EXCORE POWER DISTRIBUTION MONITORING Consumers Power Company letter dated.July 21, 1981 proposed changes to the Palisades Plant Technical Specifications.

Those changes specified new limits for radial *peaking factors and allowable linear heat rates as well as identifying the use of excore detectors for core power distribution monitoring.

Editorial changes to that submittal were made by Consumers Power Company letters dated August 6, 1981 and October 22, 1981.

During the NRC staff review of our request, it was determined that specific radial peaking factors for both 208 and 216 rod assemblies were needed.

The requested changes have been made, along with a couple of editorial corrections.

For completeness we are providing the entire Technical Specification change package as an attachment which includes all changes made to date.

Approval of these proposed Technical Specification changes and issuance of the License Amendment are required before the Palisades Plant can restart from the current refueling outage. It is anticipated that the plant will be ready for startup activities (go critical) by December 8, 1981.

David P Hoffman Nuclear Licensing Administrator CC JGKeppler, USNRC NRC Resident Inspector - Palisades

,-;-~~~~:...._~~~~~-

8111270140 0111201 PDR ADOCK 05000255 P

RDR

/

'I CONSUMERS POWER COMPANY Docket 50-255 Request for Change to the Technical Specifications License DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Provisional Operating License DPR-20, Docket 50-25S, issued to Consumers Power Company on October 16, 1972, for the Palisades Plant be changed as described in Secticm I below:

I.

Changes A:

Add the following definitions to Section 1.0:

Axial Offset The difference between the power in the lower half of the core and the upper half of the core divided by the sum of the powers in the lower, half and upper half of the core.

Narrow Water Gap Fuel Rod A fuel rod adjacent to the narrow inter-fuel assembly water gap (a gap not containing a control rod).

Narrow Water Gap Fuel Rod Peaking Factor - ~

The maximum product of the ratio of individuil fuel assembly power to core average fuel assembly power times the highest narrow water gap fuel rod local peaking factor, integrated over the total. core height including tilt.

B.

Change the title of Section 3.10 from "CONTROL ROD AND POWER DISTRIBUTION LIMITS" to "CONTROL RODS."

C.

Delete Section 3.10.3 in its entirety and replace with the following:

"3.10.3 Part-Length Control Rods The part-length control rods will be completely withdrawn from the core (except for control rod exercises and physics tests)."

D.

Changes to other sections of 3.10:

In Section 3.10.7, change 113.10.3.f" to "3.10.3." In 3.10.8, change "3.10.5 and s-s-1" to "and 3.10.5"; and "3.10.3" to. "3.23."

E.

Delete the foliowing from the "Basis" section of Section 3.10:

(1)

The paragraph starting with "The limitation on linear heat... "

and ending with "... rate limit is not exceeded."

(2)

The first four sentences of the next paragraph, from:

"When a flux tilt exists... " to "... local and total power distribution."

(3)

The paragraph starting with "The limitations on ~... " to "... rod group insertion limits."

nu0781-0171a-43

\\.

F.

Delete "(6) XN-NF-77-24" and "(7) XN-NF-i'S-16" from the "References" section of Section 3.10.

G.

Delete Figures 3-9 and 3-10 (they will be replaced by Figures 3.23-1 and 3.23-2).

nu0781-0171a-43 2

1,"

H.

Delete Section 3.11 in its entirety and replace with the following:

3.11 POWER DISTRIBUTION INSTRUMENTATION 3.11.1 INCORE DETECTORS LIMITING.CONDITION FOR OPERATION The incore detection system shall be operable:

a.

With at least 50% of the incore detectors and 2 incores per axial level per core quadrant.

b.

With the incore alarming function of th~ datalogger operable and alarm setpoints entered into the datalogger *

. APPLICABILITY (1)

Item a. above is applicable when the incore detection system is used for:

Measuring quadrant power tilt, Measuring radial peaking factors, Measuring linear heat rate (LHR), or Determining target Axial Offset (AO) and excore monitoring

allowable power level.

(2)

Items a. and b. above are applicable when the incore detection system is used for monitoring LHR with automatic alarms.

(Incore Alarm System.)

ACTION 1:

With less than the required number of incore detectors, do not use the system for the measuring and calibration functions under (1) above.

ACTION 2:

With the alarming function of the datalogger inoperable, do not use the system for automatic monitoring of LHR (Inoperable Incore Alarm System).

nu0781-0l 7la-43

POWER DISTRIBUTION INSTRUMENTATION 3.11.l INCORE DETECTORS LIMITING CONDITION FOR OPERATION ACTION 2:

(Contd)

Operation may continue using the excore monitoring system as specified in 3.11.2 or by meeting the requirements of 3.23.1.

Basis The operability of the incore detectors with the specified minimum

,complement of equipment ensures that the measurements obtained from use of this system accurately represent the spatial neutron flux distribution of the reactor core.

The operability of the incore alarm system depends on the availability of the datalogger as well as the operability of a minimum number of incore detectors.

Incore alarm setpoints mu.st be updated periodically based on measured power distributions.

The incore detector Channel Check is normally performed by an off-line computer program that correlates readings with one another and with computed power shapes in order to identify inoperable detectors.

nu0781-017la-43

POWER DISTRIBUTION INSTRUMENTATION 3.11.2 EXCORE POWER DISTRIBUTION MONITORING SYSTEM LIMITING CONDITION FOR OPERATION The excore monitoring system shall be operable with:

a.

The target Axial Offset (AO) and the Excore Monitoring Allowable Power Level (APL) determined within the previous 31 days using the incore detectors, and the measured AO not deviated from the target AO by more than 0.05 in the previous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

b.

The AO measured by the excore detectors calibrated with the AO measured by the incore detectors.

c.

The quadrant tilt measured by the excore detectors calibrated with the quadrant tilt measured by the incore detectors.

APPLICABILITY:

(1)

Items a., b. and c. above are applicable when the excore detectors are used for monitoring LHR..

(2)

Item c. above is applicable when the excore detectors are used for monitoring quadrant tilt.

ACTION 1:

With the excore monitoring system inoperable, do not use the system for monitoring LHR.

ACTION 2:

If the measured quadrant tilt has not been calibrated with the incores, do not use the system for monitoring quadrant tilt.

Basis The excore power distribution monitoring system consists of Power Range Detector Channels 5 through 8.

The operability of the excore monitoring system ensures that the assumptions employed in the PDC-II analysis(!) for determining AO limits that ensure operation within allowable LHR limits are valid.

nu0781-0171a-43-48

POWER DISTRIBUTION INSTRUMENTATION 3.11.2 EXCORE POWER DISTRIBUTION MONITORING SYSTEM LIMITING CONDITION FOR OPERATION Basis (Contd)

Surveillance requirements ensure that the instruments are calibrated to agree with the incore measurements and that the target AO is based on the current operating conditions.

Updating the Excore Monitoring APL ensures that.the core LHR limits are protected within the +/- 0.05 band on AO.

The APL considers both LOCA and DNB based LHR limits, and factors are included to account for changes in radial power shape and LHR limits over the calibration interval.

The APL is determined from the following:

LHR(Z)TS APL = [ *

]

x Rated Power

~

LHR(Z)Max x V(Z) x Ep(Z) x 1.02 Min Where:

(1)

(2)

(3)

(4)

LHR(Z)TS is the limiting LHR vs Core Height (from Section 3.23.1),

LHR(Z)Max is the measured peak LHR including uncertainties vs Core Height, V(Z) is the function (shown in Figure 3.11-1),

E (Z) is a factor to account for the reduction of allowed LHR in the peak rod p

with increased exposure (Figure 3.23.2) such that:

For fuel rod burnups less than 21:0 GWd/MT - E = 1.0 p

For fuel rod burnups greater than 27.0 GWd/MT but less than 33.0 GWd/MT -

E = 1.0 + 0.0064 x LHR p

For fuel rod burnups greater than 33.0 GWd/MT - E = 1.0 + 0.0012 x LHR p

Where LHR is the measured fuel rod average LHR in kW/ft, nu0781-017la-43

POWER DISTRIBUTION INSTRUMENTATION 3.11.2 EXCORE POWER DISTRIBUTION MONITORING SYSTEM LIMITING CONDITION FOR OPERATION Bas.is (Contd)

(5)

The factor of 1.02 is an allowance for the effects of upburn, (6)

The quantity in brackets is the minimum value for the entire core at any elevation (excluduig the top and bottom 10% of core) co~sidering limits for peak rods, interior fuel rods and narrow water gap fuel rods.

E (Z) p is only applied if the minimum value is based on limits for the peak rod.

If the quantity in brackets is greater than one, the APL shall be the rated power level.

Reference (1)

XN-NF-80-47 nu0781-017la-43

l'o 18 I. 16

(.91l,l.150)

(l.0,1.150).

I. Ill 1.12 I. I 0 (0,1.11)

(0.77,1.11) 1.08 N -

1.06 I. Oil 1.02 I. 00 0.98 o.o O. I 0.2 0.3 O. ll 0.5 o.a 0.7 0.8 0.9 1.0 FRACTION OF ACTIVE FUEL HEIGHT AXIAL VARIATION BOUNDING CONDITION FIGURE 3.11-1 Palisades

. Technical Specifications

I.

Add Section 3.23 as follows:

3. 23 POWER DISTRIBUTION LIMITS 3.23.1 LINEAR HEAT RATE (LHR)

LIM.ITING CONDITION FOR OPERATION The LHR in the peak power fuel rod at the peak power elevation Z shall not exceed the value in Table 3.23-1 times FA(Z) times FB(E) [the function FA(Z) is shown in Figure 3.23-1 and the function FB(E) wnere E is the fuel rod burnup is shown in Figure 3.23-2].

The LHR at the peak power elevation in any interior fuel rod or narrow water gap fuel rod shall not exceed the value in Table 3~23-1 times FC(Z) [the function FC(Z) is shown in Figure 3.23-3].

APPLICABILITY:

Power operation above 50% of rated power.

ACTION 1:

When using the incore alarm system to monitor LHR, and with four or more coincident incore alarms, initiate within 15 minutes corrective action to reduce the LHR to within the limits and restore the incore readings to less than the alarm setpoints within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months or failing this, be at less than 50% of rated power within the following 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

ACTION 2:

When using the excore monitoring system to monitor LHR and with the AO deviating from the target AO by more than 0.05, discontinue using the excore monitoring system for monitoring LHR.

If the incore alarm system is inoperable, within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months be at 85% (or less) of rated thermal power and follow the procedure in ACTION 3 below.

nu0781-0171a-43-48

POWER DISTRIBUTION LIMITS 3.23.1 LINEAR HEAT RATE (I.HR)

LIMITING CONDITION FOR OPERATION ACTION 3:

If the incore alarm system is inoperable and the excore monitoring system is not being used, operation at less than or equal to 85% of rated power may continue provided that incore readings are recorded ~anually.

Readings shall be taken on a minimum of 10 individual detectors per quadrant (to include 50% of the total number of detectors in a 10-hour period) within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months and at least every 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months thereafter. If readings indicate a local power level equal to or greater than the alarm setpoints, the action specified in ACTION 1 above shall be taken.

Basis The limitation on I.HR ensures that, in the event of a LOCA, the peak temperature of the cladding will ~ot exceed 2200°F. (l)

In addition, the limitation on I.HR for the highest power fuel r.od, narrow water gap fuel rod and interior fuel rod ensures that the minimum DNBR will be maintained above 1.30 during anticipated transients; and, that fuel damage during Condition IV events such as locked rotor will not exceed acceptable 1. 't (2)(3) 1ID1 s.

The inclusion of the axial power distribution term ensures that the operating power distribution is enveloped by the design power distributions.

Either.of the two core power distribution monitoring systems (the incore alarm system or the excore monitoring system) provides adequate monitoring of the core power distribution and is capable of verifying that the I.HR does not exceed its limits.

The incore alarm system performs this nu0781-017la-43

f **

POWER DISTRIBUTION LIMITS 3.23.l

LINEAR HEAT RATE (IJIR)

LIMITING CONDITION FOR OPERATION Basis (Contd) function by continuously monitoring the local power at many points throughout the core and comparing the measurements to predetermined setpoints above which the limit on IJIR could be exceeded.

The excore monitoring system*performs this function by providing comparison of the measured core AO with predetermined AO limits based on incore measurements.

An Excore Monitoring Allowable Power Level (APL), which may be less than rated power, is applied when using the excore monitoring system to ensure that the AO limits adequately restrict the IJIR to less than the limiting values. (4)

If the incore alarm system and the excore monitoring system are both inoperable, power will be reduced to provide margin between the actual peak IJIR and the IJIR limits and the incore readings will be manually collected at the terminal blocks in the control room utilizing a suitable signal detector.

If this is not feasible with the manpower available, the reactor power will be reduced to a point below which it is improbable that the IJIR limits could be exceeded.

The time interval of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and the minimum of 10 detectors per quadrant are sufficient to maintain adequate surveillance of the core power distribution to detect significant changes until the monitoring systems are returned to service.

To ensure.that the design margin of safety is maintained, the determination of both the incore alarm setpoints and the APL takes into account a measurement uncertainty factor of 1.10, an engineering nu0781*017la-43

POWER DISTRIBt.ITION LIMITS 3.23.1 LINEAR HEAT RATES (I.HR)

LIMITING CONDITIONS OF OPERATION Basis (Contd) uncertainty factor of 1.03, a thermal power measurement uncertainty factor of 1.02 and allowance for quadrant tilt.

References (1)

XN-NF-77-24 (2)

XN-NF-77-18 (3)

XN-NF-78-16 (4)

XN-NF-80-47 nu0781-017la-43

TABLE 3.23-1 LINEAR HEAT RATE LIMITS Fuel Rod Type No of Fuel Rods 208 Peak Rod 15*. 28 Narrow Water Gap Rod 15.12

-Interior Rod 14.17 TABLE 3.23-2 in Assembly 216

14. 72 14.47 13.89 RADIAL PEAKING FACTOR LIMITS, FL Peaking Factor No of Fuel Rods in Assembly 208 216 Assembly

~

1.43 1.45 r

Peak Rod FT

1. 77

1. 77 r

Narrow Gap Rod FN

1. 75

1. 74 r

I Interior Rod F.6H r

1.64

1. 67 nu0781-0171a-43-48 I

IX 3 0.9 i

z u...

0 o.e z

0 t;

IX u... -

UJ

....I m

~ 0.65

....I

...J

0.1 ACCEPTABLE OPERATION 0.2 0.3 BREAK POINTS:

I. (. "9 ' I. 0)

2. (.7,.91)

3. (1.0,.67) 0.5

~.6 0.7 0.8 LOCATION OF AXIAL POWER PEAK (FRACTION OF ACTIVE FUEL HEIGHT)

ALLOWABLE LHR AS A FUNCTION OF PEAK POWER LOCATIO" Palisades Technical Specification$

0.9 1.0 FIGURE 3.23-1

IX

c _,

>C 4(

z u....

0 0.8

z:

0 l-e.>

4(

IX o.e u...

0."

0.2 (ll3.60, 0.78)

ACCEPTABLE OPERATION 0

5 10 15 20 25 30 35 110 FUEL ROD BURNUP (GWD/MT)

ALLOWABLE LHR AS A FUNCTION OF BURNUP Palisades Technical Specifications FIGURE 3.23-2

a::

3

E

E 0.9

~

u.

0 z

0 t-u

~

a::

u.

0.8 0

0.1 ACCEPTABLE OPERATION

.. '/

0.2 0.3 o.ai BREAK POINTS:

I * (. 119, I. 0)

2. (LO,.78) 0.5 0.6 0.7 0.8 LOCATION OF AXIAL POWER PEAK (FRACTION OF ACTIVE FUEL HEIGHT)

ALLOWABLE LHR AS A FUNCTION OF PEAK POWER LOCATION FOR INTERIOR FUEL RODS Palisades T echnlcal Specifications

2.

0.9

. 1.0 FIGURE 3.23-3

\\.

POWER DISTRIBUTION LIMITS 3.23.2 RADIAL PEAKING FACTORS LIMITING CONDITION FOR OPERATION The radial peaking factors F~, F;, rr: and F~ shall be less than or equal to the value in Table 3.23-2 times the quantity [1.0 + 0.5(1-P)] where Pis the core thermal power in fraction of rated power.

APPLICABILITY:

Power operation above 50% of rated power.

ACTION:

With any radial peaking factor exceeding its limit within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , reduce thermal power to less than the lowest value of:

F

[1 - 2 (_E - 1)] x Rated Power FL Where F is the measured value of either FA FT

~r or FtJlr and FL is the r

r' r'

, corresponding limit from Table 3.23-2.

Basis*

The limitations on FA, FT F6H and FN are provided to ensure that assumptions r

r' r

r used in the analysis for establishing DNB margin, IJIR and the thermal margin/

low-pressure an4 high-power trip *setpoints remain valid during operation.

Data from the incore detectors are used for determining the measured radial peaking factors.

The periodic surveillance requirements for determining the measured radial peaking factors provide assurance that they remain within prescribed limits.

Determining the measured radial peaking factors after each fuel loading prior to exceeding 50% of rated power provides additional assurance that the core is properly loaded.

nu0781-0171a-43-48

POWER DISTRIBUTION LIMITS 3.23.3 QUADRANT POWER TILT - Tq LIMITING CONDITION FOR OPERATION The quadrant power tilt (T ) shall not exceed 5%.

q APPLICABILITY:

Power operation above 50% of rated power.

ACTION:

1.

With the quadrant power tilt determined to exceed 5% but less than or equal to 10%, correct the power tilt within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or determine within the next 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and at least ~nee every 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter, that the radial peaking factors are within the limits of Section 3.23.2, or reduce power at the normal shutdown rate to less than 85% of rated power.

2.

With the quadrant power tilt determined.to exceed 10%, correct the quadrant power tilt within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months after exceeding the limit or reduce power to less than 50% of rated power within the next 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

3.

With the quadrant power tilt determined to exceed 15%, be in at least hot standby within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Basis Limitations on quadrant power tilt are provided to ensure that design safety margins are maintained.

Quadrant power tilt is determined from excore detector readings which are calibrated using incore detector measurements. {l)

Calibration factors are determined from incore measurements by performing a two-dimensional, full-core surface.fit of deviations between measured and theoretical incore readings and integrating the fitting function over each core quadrant.

Values of LHR and radial peaking factors are increased by the value of quadrant tilt.

nu0781-017la-43

_,l...

POWER DISTRIBUTION LIMITS 3.23.3 QUADRANT POWER TILT - T q LIMITING CONDITION FOR OPERATION References (1)

FSAR, Section 7.4.2.2 nu0781-0171a-43

J.

Add Sections 4.18 and 4.19 as follows:

4.18 POWER DISTRIBUTION INSTRUMENTATION 4.18.1 INCORE DETECTORS SURVEILLANCE REQUIREMENTS 4.18.1.l The incore detection system shall be demonstrated operable:

a.

By performance of a Channel Check prior to its use following a core alteration and at least once per 7 days during power operation when required for the functions listed in Section 3.11.L

b.

At least once per refueling by performance of a Channel Calibration which exempts the neutron detectors but includes electronic components.

4.18.1.2 The incore alarm system is demonstrated operable through use of the datalogger program out-of-sequence alarm.

The out-of-sequence alarm is demonstrated operable once per refueling by performance of a Channel Check.

nu0i81-017la-43

POWER DISTRIBUTION INSTRUMENTATION 4.18.2 EXCORE MONITORING SYSTEM SURVEILLANCE REQUIREMENTS 4.18.2.1 At least every 31 days of power operation:

a.

A target AO and excore monitoring allowable power level shall be determined using excore and incore detector readings at steady state near equilibrium conditions.

b.

The excore measured AO shall be compared ~o the incore measured AO.

If the difference is greater than 0.02, the excore monitoring system shall be recalibrated.

c.

The excore measured Quadrant Power Tilt shall be compared to the incore measured Quadrant Power Tilt. If the difference is greater than 2%, the excore monitoring system shall be recalibrated.

nu0781-0 l 7la-43

. )

4.19 POWER DISTRIBUTION LIMITS 4.19.1 LINEAR HEAT RATES SURVEILLANCE REQUIREMENTS 4.19.1.l When using the incore alarm system to monitor LHR, prior to operation above 50% of rated power and every 7 days of power operation thereafter, incore alarms shall be set based on a measured power distribution.

4.19.1.2 When using the excore monitoring system to moni.tor LHR:

a.

Prior to.use, verify that the measured AO has not deviated from the target AO by more than 0.05 in the previous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

b..

Once per day, verify that the measured Quadrant Power Tilt is less than or equal to 3%.

c.

Once per hour, verify that the power is less than or equal to the APL and not more than*10% of rated power greater than the power level used in determining the APL.

d.

Once per hour, verify that the measured AO is within 0.05 of the established target AO.

nu0781-017la-43

4.19 POWER DISTRIBUTION LIMITS 4.19.2 RADIAL PEAKING FACTORS SURVEILLANCE REQUIREMENTS 4.19.2.1 The measured radial peaking factors crA, FT, F~ and~)

r r

obtained by using the incore detection system, shall be determined to be less than or equal to the values stated in the LCO at the following intervals:

a.

After each fuel loading prior to operation*above 50% of rated power, and

b.

At least. once per week of power operation.

nu0781-0171a-43

4.19 4.19.3 POWER DISTRIBUTION LIMITS QUADRANT POWER TILT - T q SURVEILLANCE REQUIREMENTS 4.19.3.1 Calculate the Quadrant Power Tilt using the excore r~adings at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months when the excore detectors deviation alarms are inoperable.

nu0781-017la-43

.y ; **

K.

Add Item 16 and Note (h) to Table 3.17.4.

No 16 Functional Unit Excore Detector Deviation Alarms Table 3.17.4 (Contd)

Minimum Operable Channels Minimum Degree of Redundancy None Permissible Bypass Conditions None (h)

Calculate the tilt using excore readings once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months when the excore detector deviation alarms are inoperable.

nu0781*017la-43.

.i:

j II.

DISCUSSION The proposed Technical Specification changes are intended to accomplish four objectives:

1.

To incorporate a burnup dependent linear heat rate limit for H, I and future fuel types.

2.

To modify the radial peaking factor limits.

3.

To adopt power.distribution monitoring with the excore detectors as an alternative to the incore alarms.

4.

To adopt the standard Technical Specifications format for power distribution monitoring and power distribution limits.

A.

Burnup Dependent Linear Heat Rate Limit The basis for the burnup dependent LHR limit is in the Appendix to XN-NF-81-34.

The allowable LHR is.reduced at fuel rod average burnups greater than 27.25 GWd/MT to offset the adverse effects of fission gas release on predicted clad rupture and flow blockage..

This limit is implemented in the Technical Specifications by the additional multiplicative term, FB(E) in the equation for limiting LHR.

F8(E) is shown in Figure 3.23-2.

Since the separate LHR limits for interior fuel rods and narrow water gap fuel rods are based on DNB considerations only, the burnup dependent limit is not applied to them unless they are also the peak LHR rods within an assembly.

In addition, since separate DNB analyses were performed for assemblies containing 208 fuel rods and 216 fuel rods, separate LHR limits are applied to each fuel type for the peak fuel rod, narrow gap fuel rod and interior fuel rod.

The limits are derived from the allowable radial peaking factors in combination with the axial peaking limits identified in XN-NF-78-16.

nu0781-017la-43-48

B.

Radial Peaking Factors New limits for Assembly Radial Peaking Factor - ~. Total Radial Peaking Factor - FT and Total Interior Fuel Rod Radial Peaking r

61{

Factor - F are proposed.

A new limit, Total Narrow Water Gap Fuel r

Rod Peaking Factor -

F~; is also included.

The basis for these limits are presented in Section 7.0 of XN-Nf-81-34.

As in the case of the LHR limits, separate radial peaking factor limits are proposed for 208 rod and 216 rod assemblies based on the: results of the thermal hydraulic analyses.

The LOCA analysis is limiting for wide gap fuel rods, so that the previous limit of 1.77 is retained for the total radial peak.

C.

Excore Power Distribution Motiitoring The proposed Technical Specifications also include provisions for monitoring the limits on LHR with the split excore detectors as an alternative to the incores when the datalogger is inoperable.

The method employed is based on Exxon Nuclear Company's PDC-II as previously reported in XN-NF-77-57, "Exxon Nuclear Power Distribution Control for Pressurized Water Reactors, Phase 2," dated January 1978.

In this method, a target axial offset and an allowable power level are chosen periodically based on incore measurements of margin to the LHR limits.

Operation is then allowed within a narrow axial offset band around the target.

The method was originally formulated for Westinghouse reactors, so an analysis was performed to verify its applicability to Palisades.

The report of this analysis, XN-NF-80-47, "Palisades.Power Distribution Control Procedures;" dated 1980 is enclosed.

nu0781-0171a-43-48

ii..**.,,,

The Palisades instrument used to measure axial offset (the Power Ratio Recorder) does not have all the features of the corresponding Westinghouse system:

(Neither the target offset nor the allowable offset band.width can be varied automatically with power level, and there is no timer to automatically record time outside the target band.)

Because of this, only a very limited portion of the procedure allowed under PDC-II is being implemente~. There is only one allowable offset target band (+/- 0.05} and it does not vary with power level.

If the datalogger is inoperable and, because of the need to maneuver or some other reason, the operator cannot maintain the axial offset within the band, the existing alternative has been retained, wherein the reactor is limited to 85% power and incore outputs are recorded by hand.

D.

Standard Format It is currently planned to adopt the standard format for Palisades Technical Specifications.

Therefore, this change reorganizes portions of the existing specifications into that format.

It is expected that, with some renumbering of paragraphs, the new sections submitted herein will fit into the final form of the standard Palisades Technical Specifications with only a minor review required.

In the current change, the portion of Section 3.10 (having to do wit.h power distribution limits 3.10.3) has been moved into a new section of its own, 3.23.

Section 3.11, Incore Instrumentation, has been revised to include requirments for the excores as well as the incores and is now entitled "Power Distribution Instrumentation."*

nu0781-0171a-43-48

The following is an itemization identifying the source of the proposed specifications:

New Section Old Section 3.11.1 INCORE DETECTORS

. LCO a.

LCO b.

APPLICABILITY (1)

(2)

ACTION 1 ACTION 2 SURVEILLANCE REQUIREMENTS 4.18.1.1 4.18.1. 2 3. 11. 2 EXCORE MONITORING SYSTEM LCO a.

LCO b. 3.11.a 3.11.c &

3.11.d 3.11.a 3.11.b 3.11. a 3.11.b 3.11 Basis nu0781-0171a-43 Discussion The requirement for operable instrumentation above 50%

power is now inherent in the applicability statement for linear heat rate limits (3.23).

Since there are now five levels of incores, the requirement for 10

'detectors per quadrant is redundant to the requirement

for 2 per axial level per quadrant and has been deleted.

(Since a description of the system is not present in the Standard Technical* Specifications basis, it has been deleted from the Palisades basis also.)

Determining alarm setpoints weekly is required as before.

An operational datalogger is required for incore alarms to be operable.

The uses of the incores are specified in more detail than previously.

Incore alarms are not necessary for measurement functions.

The requirement for* an operable datalogger is applicable when using the alarm feature when monitoring I.HR.

Similar to Standard.

ACTION 1 corresponds to APPLICABILITY (1).

Similar to Standard.

ACTION 2 corresponds to APPLICABILITY (2).

Similar to Standard Technical Specifications.

The out-of-sequence alarm alerts the operator to datalogger problems.

Required to implement excore monitoring of linear heat rate.

Requirements conform to PDC-II methodology as outlined in XN-NF-80-47.

Axial offset must be calibrated.

New Section Old Section

.. Discussion LCO c.

3.11 Basis Quadrant tilt must be calibrated.

APPLICABILITY (1)

(2)

ACTION 1 ACTION 2 3.11. 2 Basis SURVEILLANCE REQUIREMENTS 4.18.2.1 3.23.1 LINEAR HEAT RATE LCO 3.11 Basis 3.10.3.a nu0781-017la-43 All calibrations are required for excore LHR monitoring.

Axial offset calibration is not required if the excores are only being used to monitor quadrant tilt.

Self-explanatory.

ACTION 1 corr~sponds to APPLICABILITY 1.

Self-explanatory.

ACTION 2 corresponds to APPLICABILITY 2.

The basis contains the method for selecting the excore monitoring allowable power level.

The equation implements the procedure described in Section 3.2 and 3.3 of XN-NF-80-47.

An additional factor is included that restricts the APL to account for the effects of the burnup dependent LHR.

The coefficients in the equations for E are based on the amount the LHR p

limit could decrease in 31 days of full-power opera-tion as derived from Figure 3.23-2 of the new Technical Specifications.

Surveillance implements the calibrations required for operability of the excores for the purpose of LHR monitoring and quadrant tilt surveillance.

Changes from the current specification include:

1.

The addition of the term FB(E) to the computation of peak LHR and the new Figure 3.23-2.

2.

Reduction in the limit for interior rod LHR and addition of limit on narrow water gap rod in accordance with the DNB analysis in XN-NF-81-34.

New Section Old Section 3.23.1 LINEAR HEAT RATE (Contd)

LCO 3.10.3.a APPLICABILITY 3.11.a ACTION 1 ACTION 2 ACTION 3 SURVEILLANCE REQUIREMENTS 4.19.1.1 4.19.1. 2 3.23.2 RADIAL PEAKING FACTOR LCO APPLICABILITY 3.11.b 3.11.e &

3.11. f 3.11.c &

3.11.d 3.10.3.g nu0781-017la-43 Discussion

3.

Figures 3.9 and 3.10 have been renumbered 3.23-1 and 3.23-3.

4.

The uncertainty factors are moved to the basis in accordance with the standard. format.*

The power level at which IJIR mus~ be monitored is lower than that implied by the old specification, which allowed operation up to 65% power without incores.

The new specification is similar to the Standard Specifications.

Axial Offset Monitoring as a backup to the incore alarms is proposed.

If the Axial Offset cannot be maintained within the allowed band, operation may continue using the incores following the procedure in ACTION 3.

The new specification is the same as the old.

The new requirement is similar to the old.

The surveillance ensures that axial offset, power level and quadrant tilt remains within the bounds of the PDC-II analysis.

~ and FtJi have been decreased to conform to the Cycle 5 DNB analysis, and a new limit on narrow water gap rod peaking factor has been added.

The exception for H fuel in Cycle 4 has been dropped..

The applicability is the same as for linear heat rate limits.

New Section Old Section 3.23.2 RADIAL PEAKING FACTOR (Contd)

ACTION SURVEILLANCE REQUIREMENTS 4.19.2.1 3.23.3 QUADRANT POWER TILT LCO APPLICABILITY ACTION

1.

2.

3.

SURVEILLANCE REQUIREMENTS 4.19.3.1 3.11.g 3.11.d &

3.11.g 3.10.3.e 3.10.3.e 3.10.3.c 3.10.3.b nu0781-017la-43 Discussion The new requirement is similar to the old.

The new requirement is similar to the old.

The limit of 0.05 is the same as before.

The applicability is the same as for LHR limits.

The action statement for 0.05 tilts is more conserva-tive than the old because it requires immediate correctiv.e action.

Reductions to 85% power is sufficient to assure safe operation with tilts less than 10%.

Again the action is more conservative than the old because the 24-hour delay has been eliminated.

The old requirement is unrealistic.

Increasing the thermal margin low-pressure trip setpoint by 400 psi would trip the plant, so the result would be a shut-down in any case.

Methods of measuring LHR are not valid for very large tilts.

No specific surveillance requirements are in the current specifications.

ML18046B098

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