ML20204E817

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Proposed Tech Specs Re Linear channel-high Neutron Flux Trip Setpoints
ML20204E817
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 10/13/1988
From:
PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML20204E791 List:
References
NUDOCS 8810210456
Download: ML20204E817 (9)
v • d • e


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Attachment 2 To P-88379 l i

SUMMARY

OF PROPOSED CHANGES b

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P-88379 Page 2 Attachment 2 October 13, 1988 SECTION LCO 4.4.1 Page 4.4-2. Modify the requirement to shut down the reactor within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> following a power reduction resulting in noncompliance with Figure 3.3-1, to permit 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to reset detectors per Figure 3.3-1 and an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to shut down the reactor if compliance is not accomplished.

Page 4.4-2. Also, revise actions for Table 4.4-3 to specify actions to "shut down" in lieu of "shutdown" for editorial clarification.

Page 4.4-3b. Correct Items 6 and 7 to read "see Table 3.3-1" instead of "see Table 3.3-2". Table 3.3-2 does not exist.

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l Attachment 3 l i-To P-88379  !

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PROPOSED REVISIONS TO LCO 4.4.1 -

l OF THE FSV TECHNICAL SPECIFICATIONS

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Fort St. Vrain #1 Technical Specifications

. Amendment #

Page 4.4-2 l For Tacle 4.4-1, the reactor ..all be shut dcwn witnin l 12 nours with two exceptions:

l a. To facilitate maintenance on the Plant Protective System (PPS) moisture menitors, the moisture monitor input trio functions to the Plant Protective System wnich cause scram, loop shutdown, circulator trip, and steam water dump may be disabled for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

During the time tnat the Plant Protective System moisture monitor trips are disabled, an observer in direct communication with the reactor operator shall be positioned in the control room in the location of pertinent instrumentation. The observer shall continuously monitor the prima ry coolant moisture levels indicated by at least two moisture monitors and the primary coolant pressure indications, and shall alert the reautor operator to any indicated moisture or pressure change. During the time in which the trip functions are disabled the requirements of LCO's 4.2.10 and 4.2.11 shall be met and primary coolant shall not exceed a moisture concentratton of 100 ppmv.

l b. Tne linear enannel-nign neutron flux TRIP SETPOINTS l must be in compliance with tre recuirements of Figure l 3.3-1 within 12 nours after a cower reduction where a l different TRIP SETPOINT is acciicable, or the reactor l shall oe shut cown witnin the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

For Table 4.4-2, the affected loop shall be shut down within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

For Table 4.4-3, perform one of the following witnin 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s:

I a. Tne reactor shall be shut cown, or I i

l b. tne affected helium circulator shall ce shut down.

For Table 4.4-4, the reactor snall ce shut d wn within 24 hcurs.

If, witnia the irdicated time limit, tne minimur num0er of opera:1e :maanels and tne minimum cegree of recurdancy can be reestsolisnec, the system is censidered normal and no furteer 1:tior needs to be tasen.

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Fort St. Vrain #1

. Technical Specifications

. Amendment No.

Page 4.4-3b Sce:1fication LCO 4.4.1 Table 4.4-1 (Part 1)

INSTRUMENT OoERATING REQUIREwENTS FOR PLANT PROTECTIVE SYSTEM. SCRAM TRIP ALLOWABLE NO. FUNCTIONAL UNIT SETPOINT VALUE I 6. Primary Coolant Pressure ---------See Table 3.3-1---------

-Programmed Low l 7. Primary Coolant Pressure ---------See Tatie 3.3-1---------

-Programmed High

8. Hot Reheat Header Pressure > 44 psig 3 43 psig

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9. Main Steam Pressure-Lo. 31529 psig 31517 psig
10. Plant Electrical System-Loss > 2?dV > 266V 331.5 Seconds 335 Seconds
11. Two Looo Trovele Not Applicable Not Applicable
12. High Rea: tor Building $ 161 cegree F $ 166 cegree F Temperature (Pice Cavity)

Notes for Tables 4.4 1 through 4.4-4 are or Pages 4.4 8 and 4.4-9

4 Attachment 4 To P-88379 SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS

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P-88379 Page 2 Attachment 4 October 13, 1988 SIGNIFICANT HAZARDS CONSIDERATION EVALVATION: i The proposed Amendment would modify Technical Specification Section LCO 4.4.1, which provides a listing of the Plant Protective  !

System (PPS) instrumentation parameters and the associated bases. I r

The PPS is the ret.ctor protective circuitry and the etreuitry '

oriented towards protecting various plant components from major  :

danage.  !

The Technical Specification LCO 4.4.1 has been modified to -

clarify the time permitted to reset trip setpoints per the detector decalibration curve, Figure 3.3-1, for the linear channel - high neutron flux channalt following a power reduction.

If the linear channel - high neutron flux channels are outside their ALLOWABLE VALUES, they must be considered inoperable and the appropriate actions apply. The linear channel - high neutron flux RWP and scram will be available but may not be set properly.

Amendment 60 requires a plant shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. There are various plant situations where power level is automatically reduced and the applicable TRIP SETPOINTS for the linear channel - high neutron flux channels change.

To avoid unnecessary shutdown requirements af ter control rod runback or power reduction events, PSC proposes that an action be r added to the FSV Technical Specifications that allows 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after  ;

a power reduction to regain compliance with Figure 3.3-1 for linear '

channel - high neutron flux. This added action provides a reasonable period ef time to regait! con 11ance, either by adjusting the TRIP  !

SETPOINf 5 or by changing power level, during which the iinear channel l

- high neutron flux RWP and scram (which may be improperly set), and I the reheat steam temperature-high scrae provide protection against an l unexpected increase in power level. The likelihood of a rod  !

withdrawal accident (for which these scram parameters provide l protection) is small. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> nrderly shutdown requirement  !

reduces rapic transients on plant components and is consistent with i actions includad in the FSV Technical Specification Upgrade Program j draf t, submitte.d in Reference 3 (P-88184).  ;

BASIS FOR N0 SIG'4IFICANT HAZARDS _ DETERMINATION! [

The proposed amendment does not involve a significant ha:Ards consideration because operation of the Fort St. Vrain Nuclear l Generating Station in accordance with this change would not: [

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P 88379 Page 3 Attachment 4 October 13, 1988

1) Involve a significant increase in the probability or consequences of an accident previously evaluated. '

The linear channel - high neutron flux parameters are part of the Plant Protective System (PPS). The primary function .

of the linear channel - high neutron flux parameters is to E provide a scram prior to reactor power exceeding 140*. of rated power. Additional protection is provided by a rod withdrawal prohibit prior to reactor power exceeding 120?, of rated power. These high neutron flux scram and RWP actions are backed up by the PPS reheat steam temperature -

high scram. Section 14.2.2 of the FSAR analyzes accident scenarioc that would produce reactor power levels of 140*. of rated power. The condition that is most likely to cause an increase in power level of this nature is a rod withdrawal accident. Section 14.2.2.6 analy:es maximum worth control rod pair withdrawal at full power. Included are scenarios where the reactor is scrammed 88 seconds and 105 seconds af ter accident initiation by the reheat steam temperature -

high scram. These accident analyses are not modified by this amendment.

2) Create the possibility of a new or different kind of accident from any accident previcusly evaluated.

FSAR Section 14.2.2 contains the analysis of core reactivity accidents. Permitting a reasonable amount of time to regain compliance with Figure 3.3-1 for the linear channel - high neutron flux channels and a reasonable amount of time to shut down the reactor in an orderly manner does not change that analysis

3) Invo' eve a significant reduction in a margin of safety.

The margin of safety a g a i r,st an increase in reactivity accident is provided by five protective actions identified in FSAR Section 14.2.2.1. This amendment clarifies the time that is available to regain compliance with Figure 3.3-1 for two of these protective actions following a power reduction that chsnges the applicable trip setpoints for the linear channels. Any reduction of safety during this time is not significant in that all fivt protective actions are available. (The RWP and scram for the linear channels may be improperly set on an interim bases.) The effectiveness of the other three protective actions is analyzed in FSAR Section 14.2.2.6. The other protective actions include reheat steam temperature - high scram, manual scram, and manual actuation of the reserve shutdown system.

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P-88379 Page 4 Attachment 4 October 13, 1983 In this requested rovision to LCO 4.4.1 for the power reduction situation, 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> woLid be permitted to ensure proper trip setpoints for the linear channel - high neutron flux channels. This could include either adjusting the trip

setpoints for the lower power level, or increasing reactor power, if appropriate. Also, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be permitted to effect an orderly shutdown of the reacto: in the unlikely event that compliance with Figure 3.3-1 could not be regained. Interim Technical Specification LCO 3.1.5 permits 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to restore the control rods to an acceptable configuration following a_ control rod runback. The resetting of the trip setpoints must be done after the control rods are restored to an acceptable configuration.

The twelve hours includes time to position the control rods to conform to the requirements of interim Technical Specification LCO 3.1.5.

PSC considers this change to LCO 4.4.1 justified because adequate protective actions remain in place and a rod i withdrawal accident is a low probability event. During the

int 1rval in which P e high neutron flux scram trip setpoint may not be in compliance with Figure 3.3-1, the reheat steam l temperature - high scram would be available to protect

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against an unc~oected increase in reactor power. The RWP and scram due nigh neutron flux would be available but

, may not actuate by the 120% or 140% analyzed values. The i manual scram is also available in addition to the automatic scram and RWP actions.

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