ML19347C070

Application for Amend of License DPR-34,changing Tech Specs 2.0 & Tables 3.3.1 & 4.4-1 Through 4.4.4 to Revise Instrument Setpoints

ML19347C070
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/01/1980
From:	Lee O PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML19347C066	List: ML19347C065 ML19347C070 ML19347C073
References
TAC-47416, NUDOCS 8010160541
Download: ML19347C070 (11)

Text

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O BEFORE THE UNITED STATES NUCLEAR REGULATORY C0:04ISSION In the Matter of the Facility Operating License)

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of ) Docket No. 50-267

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PUBLIC SERVICE COMPANY OF COLORADO )

Application for Amendment to Appendix A of Facility Operating License License No. DPR-34 0F THE PUBLIC SERVICE CO:1PANY OF COLORADO FOR THE FORT ST. VRAIN NUCLEAR GENERATIMG STATION 1

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This application for Amendment to Appendix A of Facility Operating License, License No. DPR-3s, is submitted for NRC review and approval.

Respectfully submitted, PUBLIC SERVIJE COMPMW OF COLORADO

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By /bYYll

0. R. Lee, Vice President KELLY, STANSFIELD & 0'DONNELL Bryant O'Donnell Robert E. Thonyson Public Service Company Building Denver, Colorado 80202 Attorneys for Applicant 80101605'//-

STATE OF COLORADO )

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CITY AND COUNTY OF DENVER)

O. R. Lee, being first duly sworn, deposes and says; That he is Vice President of Production of Public Service Company of Colorado, the Licensee herein; that he has read the foregoing Application for Amendment to Appendix A of Facility Operating License and knows the contents thereof, and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.

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0. R. Lee I dayofOCTb0tp @0 Subscribedandsworntobeforemethis7 ,

Witness my hand and official seal.

My commission expires: C)c T0 /A'll (9 P 3) .

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dttM Notary Public /

O ATTACIDENT 1 REFERENCES 4

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l Attachment 1 Page 1 of 1 REFERENCES (1) Letter, Speis to Fuller, August 28, 1978 l (2) P-77196, September 20, 1977 (3) P-78192, December 5, 1978 (4) P-79038, February 5, 1979 (5) P-77188, September 7, 1977 I (6) P-77228, November 16, 1977 (7) I & E Inspection Report 77-03, G. L. Madsen to C. K. Millen, February 28, 1977 (8) P-77092, March 29, 1977

! (9) Letter, G. L. Madsen to C. K. Millen, September 19, 1977 (10) P-79012, January 11, 1979 (11) P-79275, November 29, 1979 I

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- ATTACIDfENT 2 l

METMODS EMSLOYED TO ESTABLISH NEW SETPOINTS SW. i

SUMMARY

OF PROPOSED TECHNICAL SPECIFICATION REVISIONS I 1

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g -&= W a WsW%h, - , a-e nbe w4 ew a ,si Attachment 2 J

Page 1 of 6

1. Methods Employed to Establish New Setpoints 4

Four methods have been employed in establishing the new instrument trip settings and absolute valises contained in this submittal. These are identified as Method A, Method B, Method C, and Method D.

Method A The parameter value currently identified as the " Trip Setting" has been redefined to be the absolute value. A new instrument trip setting with a setpoint tolerance which is mere conservative than the absolute value is specified. The minimum difference be-tween the absolute value and the instrument trip setting is the instrumentation accumulated inaccuracy determined by the least squares method utilizing manufacturers' published accuracy data.

Additionally, the calibration surveillance "as found" versus the "as left" data.for these instrumentaton channels were reviewed to ascertain whether decalibration or drift that occurs between calibrations does or does not routinely exceed the previously described channel accumulated accuracy. As would be expected due to the large number of instruments involved, occasionally instrument channels were found to drift outside of the specified accuracy range. These were reported in Reportable Occurrence Reports as required by the Technical Specification. For the setpoint revisions contained in this submittal, only the circu-lator seal malfunction (Item 8 of Table 4.4-3, LCO 4.4.1) has been a continuing problem. This was last documented in Re-portable Occurrence No. 50-267/80-16.

In selecting plant protective system parameters to have instru-ment trip setpoints and absolute values specified by Method A, the prime consideration was that operating experience has shown that shif ting the instrument trip setting closer to the normal operating level '4111 not induce unnecessary trips to the plant prote.ctive system.

Method B_

Operating experience at Fort St. Vrain hss shown that some plant protective system parameters are frequent candidates to be tripped during plant c:cusients which, in turn, can further aggravate the transient. In some cases, these have led to shutdown of helium i

circulators and shutdown of a coolant loop.

The frequency of these unnecessary trips to the plant protective system was increased by Nuclear Regulatory Connission actions and consequent interin operation agreements made by Public Service Com-pany of Colorado in 1977. The net result was that plant protective system setpoints were adjusted as required utilizing the Method A procedure previously described. References (7) through (9) are the documentation of these actions.and agreements.

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1-Attachment 2 Page 2 of 6 1

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1. Methods Employed to Establish New Setpoints (Continued)

Method B (continued)

In accordance with previously stated plans, a number of safety analyses supporting new absolute values and new instrument trip settings have been performed by General Atomic Company. Some of these have been previously submitted and the submittals are 2

referenced herein. Newly completed and two previously submitted safety analyses are attached to this submittal. In all case,s, the minimum difference between the absolute value and the instru-ment trip setting is equal to or greater than the accumulated channel inaccuracy as determined in Method A.

It is our judgement that incorporation of these new absolute values and instrument trip settings into the Fort St. Vrain Tech-nical Specification will enhance plant safety and availability by not unnecessarily tripping the plant protective system. It is

, further our judgement that the proposed revised settings will not negate the safety function for which it was intended, not change the consequence of accidents evaluated in the Final Safety Analy-sis Report, and thus does not constitute an unreviewed safety question.

Method C This method was applied only to the 140% thermal power scram. It is unique in that new hardware has been designed and fabricated to assure that a reactor scram occurs equal to or less than the absolute value of 140% power. This is accomplished by programming instrument trip setting against indicated power.

Method D In some cases, plant protective system parameters have been included in the Technical Specification to ensure operator compliance with administrative procedures. In those cases, no credit was assumed for mitigation of accidents by those systems in the Final Safety

Analysis Report. Therefore, specifying an absolute value for those parameters is not warranted. Specifically, those are the nominal 5% and 30% power rod withdrawal prohibits.

2. Summarv of Proposed Technical Specification .4evisions Proposed revisions to 2.0 Definitions, Table 3.3.1 of LSSS 3.3, Tables 4.4-1 through 4.4-4 of LCO 4.4.1, Notes for Tables 4.4-1 through 4.4-4, and. the Basis for Specification LCO 4.4.1 are included as Attachment 3.

The following is the discussion of each of the proposed revisions:

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Attachment 2 Page 3 of 6

2. Summarv of Proposed,_ Technical Soecification Revisions (continued)

A. Proposed Revision to Technical Soecification 2.0 Definitions Add new items d) and e) to 2.3, Instrumentation Surveillance, to define " Instrument Trip Setting" and " Absolute Value" as used in the proposed Fort St. Vrain Technical Specification revisions.

3. Proposed Setpoint Revisions - Method A Table 3.3.1 of LSSS 3.3 1.b) High Reheat Steam Te=perature 2.c) PCRV Pressure 2.d) Helium Circulator Penetration Interspace Pressure 2.e) Steam Generator Penetration Interspace Pressure Table 4.4-1 of LCO 4.4.1

5. Reheat Steam Temperature - High

9. Main Steam Pressure - Lov

12. High Reactor Building Tampsrature (Pipe Cavity)

Table 4.4-2'of LCO 4.4.1 la. through lf. Steam Pipe Rupture 2a.- High Pressure, Pipe Cavity 2b. High Temperature, Pipe Cavity 2c. High Pressure, Under PCRV 2d. High Temperature, Under PCRV Sa. Steam Generator Peneerstion 0 erpressure Loop 1 Sb. Steam Generator Penetration Overpressure Loop 2 Table 4.4-3 of LCO 4.4.1

4. Circulator Penetration Trouble l 5. Circulator Drain Malfunction

Attachment 2 Page 4 of 6

2. Sumnarv of Proposed Technical Specification Revisions (continued)

3. Proposed Setpoint Revisions - Method A (continued) '

Table 4.4-3 of LCO 4.4.1 (continued)

6. Circulator Speed - High Steam

8. Circulator Seal Malfunctions

9. Circulator Speed High Water Table 4.4-4 of LCO 4.4.1

1. Startup Channel - Low Count Rate C. Proposed Setpoint Revisions - Method B Table 4.4-1 of LCO 4.4.1

8. Hot Reheat Header Pressure - Low The safety analysis supporting the proposed revision is included in Attachment 4 Table 4.4-3 of LCO 4.4.1

1. Circulator Speed - Low The safety analysis supporting the proposed revisions is included as Attachment 5.

2a. and 2b. Loop 1 and Loop 2 Fixed Feedwater, and Flow -

Low (Both Circulators).

The safety analysis supporting the proposed revision is included as Attachment 6. It is noted that the safety analysis concluded that the absolute value could be 0% feedwater flow. However, in subsequent discussions, the !Tuclear Regulatory Commission staff have objected to specifying 0% feedwater flow as an absolute value in the Technical Specification even

- if justified by the safety analysis. In consideration of these discussions, the absolute value has been in-creased to greater than or equal to 5%.

3. Loss of Circulator Bearing Water The safety analysis supporting the proposed revision is included as Attachment 7.

Attachment 2 Page 5 of 6

2. Su= mary of Proposed Technical Specification Revisions (continued)

D. Prooosed Setpoint Revisions - Me* aod C Table 3.3.1 of LSSS 3.3 1.a) High Neutron Flux Table 4.4-1 of LCO 4.4.1 3a. Linear Channel - High, Channels 3, 4, 5 3b. Linear Channel - High, Channels 6, 7, 8 The description of the hardware and safety analysis sup-porting the programmed instru=ent trip setting for the initial core, GA Report GA-A13954, was submitted to the Nuclear Regulatory Cennission on January 11, 1979, in our letter P-79012 (Reference 10). The justification for using the progra=med instrument trip setting for the Cycle 2 core, GA Report GA-D15474, was submitted to the Nuclear Regulatory Commission on November 29, 1979, in our letter P-79275 (Reference 11).

As can be seen from the proposed revision to the Techni-cal Specification tables the programmed instrument trip setting is not specified but is to be separately approved by the Nuclear Facility Safety Comrdttee. This is consis-tent in that the programmed instrument setting is directly related to the sequence of withdrawing and inserting con-trol rods which is approved by the Nuclear Facility Safety Committee for each refueling cycle per LCO 4.1.3 - Rod Sequence; Limiting Conditions for Oceratien. ,

E. Proposed Seccoint Revisions - Method D Table 4.4-4 of LCO 4.4.1 2a. Linear Channel - Low Power KWP (Channels 3, 4, and 5) 2b. Linear Channel - Low Power KWP (Channels 6, 7, and 8) 3a. Linear Channel - High Power KWP (Channels 3, 4, and 5) 3b. Linear Channel - High Power KWP (Channels 6, 7, and 8)

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Attachment 2 Page 6 of 6

2. Summarv of Proposed Technical Specification Revisions (continued)

F. Proposed Revision to Notes for Tables 4.4-1 through 4.4-4 Add new Nota (u) to describe the approval of the programmed instrument trip setting for the linear channel high level scram.

G. Proposed Revisions to Basis for Specification LCO 4.4.1 i General - Revise the wording in the basis to reflect the use of absolute values and instrument trip settings in Tables 4.4-1 through 4.4-4.

Specific - Revise Item d) Rod Withdraw Prohibit Inputs i

The analysis supporting the proposed revisions to the table as well as the Basis for LCO 4.4.1 is in-cluded as Attachment 8.

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