ML20045F211
| ML20045F211 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 07/01/1993 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML20045F189 | List: |
| References | |
| NUDOCS 9307070095 | |
| Download: ML20045F211 (6) | |
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CONSUMERS POWER COMPANY Docket 50-155 Request for Change to the Technical Specifications License DPR-6 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Facility Operating License DPR-6, Docket 50-155, issued to Consumers Power Company on May 1, 1964, for the-Big Rock Point Plant be changed as described in Section 1 below:
- 1. CHANGES A.
Rewrite the third item of 11.4.1.4.A to read:
" Automatic actuation of both fire pumps and run the electric for at least 5 minutes and the diesel for at least 30 minutes."
B.
Add a new requirement to 11.4.1.4.B which reads:
" Verify that the electric and diesel fire pump performance meets the capacity requirement of Table ll.3.1.4.b."
C.
Add a new Table 11.3.1.4.b (attached) which contains two acceptance curves for the electric and diesel fire pumps.
D.
Add to Bases (page 96) at the end of the first paragraph:
" Adequate Core Cooling is assured when the primary core spray flow is 2 292 gpm or the back-up core spray flow is 2 296 gpm."
In the third paragraph, change "pgm" to "gpm" in the second sentence and add the following between the second and third sentence:
" Performance curves for the pumps were developed using FLOWNET computer code of the ECCS System.
Evaluation of the most limiting ECCS failures concludes adequate core cooling is achieved under these conditions."
E.
Delete 4.7.ll.l.l.b from the surveillance section, and renumber subsequent items accordingly.
F.
Delete 4.7.ll.1.1.d, item 2 from the surveillance section, and renumber subsequent items accordingly.
G.
Delete 4.7.11.1.1.d, item 3 from the surveillance section, and renumber subsequent items accordingly.
II. DISCUSSION The Fire Protection System (FPS) provides a dual function at Big Rock Point.
First, in providing water from Lake Michigan via an electric and/or diesel fire pumps for fire fighting (hoses and nozzle spray systems).
Second, unlike any other plant, the FPS provides flow to the Emergency Core Cooling and Containment Spray Systems using the same two pumps.
The function and relationship of these systems is further described in sections 6.3 and 9.5.1 of the Updated Final Hazards Summary Report (FHSR) for Big Rock Point.
The Techtical Specifications for Big Rock Point when originally issued included operability and surveillance requirements for the ECCS and Containment Spray Systems.
However, testing requirements were limited to the actuation circuits for the motor operated valves and did not include pump testing.
Following completion of the ECCS analyses in compliance with 10 CFR 50 Section 50.46 and Appendix K, additional ECCS operability and surveillance requirements were added as part of Amendment 10 issued on June 4, 1976. This Specification Change which followed Commission 9307070095 930701 D
PDR ADOCK 05000155-d 9
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TECH SPEC CHANGE ~ REQUEST -
2 ECCS ACCEPTANCE CRITERIA II. DISCUSSION (Continued) guidance added fire pump testing but only included monthly starts, not capacity tests. Amendment 17, dated March 6, 1978,_added Fire Protection requirements to the BRP Technical Specifications.
This Amendment i
duplicated the monthly start test contained in the ECCS section but also added a capacity test every 18 months which required verification that the pumps will develop a flow of 1000 gpm at 110 psi. This acceptance criteria was not based on ECCS flow requirements but rather the pump manufacturer's rating.
In response to ASME B&PV Code,Section XI, IWP requirements, Big Rock Point began condecting flow tests on both fire pumps in about 1980.
However, this testing is used for trending analysi.s and does not evaluate ECCS performance requirements.
Change A adds the minimum run times of 5 (electric) and 30 (diesel) minutes to the existing monthly surveillance requirement to start both pumps. As discussed above, the monthly start requirement is contained in both the Fire Protection and ECCS sections of the Technical Specifications and by adding the run times to the ECCS section, duplication is eliminated.
Change E removes the monthly start test from the Fire Protection Section.
Change B and C adds a new requirement to perform a capacity test of both fire pumps at each major refueling outage.
Change C adds the acceptance criteria curves for both pumps. The two curves were established using the FLOWNET computer code as discussed below to assure that' ECCS design
'i flows of 292 gpm (ring) or 296 gpm (nozzle) are maintained.
Implementation of this testing will resolve the concern as discussed in the cover letter.
Development of Table 11.3.1.4.5 The required ECCS flow rates of 292 or 296 gpm for the primary (ring) and backup (nozzle) sprays, respectively, were determined following extensive 10 CFR 50 Appendix K analyses and flow distribution testing as described in the Consumers Power Company submittal dated April 15, 1993.
These analyses were based on the requirement to remove the decay heat load 20.4 to 30 secor,ds (time-to-rated spray for various break sizes) following a reactor trip.
Since in-situ ECCS flow testing was not possible, a FLOWNET model of the Big Rock Point ECCS was used to analytically determine that the required flow rates could be achieved under design bases conditions.
The FLOWNET computer code used manufacturer's design head curves for both the electric and diesel fire pumps and evaluated the most limiting ECCS flow configurations based upon the single failure criterion.
This resulted in the following five limiting failures which j
were modeled:
Diesel Generator Failure Diesel Fire Pump Failure Electric Fire Pump Failure 4" Ring Spray Line Break 4" Nozzle Line Break
TECH SPEC CHANGE REQUEST -
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ECCS ACCEPTANCE CRITERIA II. DISCUSSION (Continued)
The pump head curves listed in Table 11.3.1.4.5 were developed from-recent inservice testing data for both the diesel and electric fire pumps.
FLOWNET parametric calculations were performed to determine the limiting electric and diesel pump head curves that still satisfied the ECCS design flow requirments.
The following table summarizes the results using the head curves from-Table 11.3.1.4.6:
DETERMINATION OF FIRE PUMP ACCEPTANCE CURVES FLOWNET RESULTS FLOWS CONTAINMENT SPRAY FAILURE CASE PRESSURE RING N0ZZLE (0UTSIDE (INSIDE
~ !
RX/ CONT SPRAY SPRAY SD ENCL)
SD ENCL)
(osia) 7
- Diesel 2A 70/10 295.7 73.3 68.0 4
Generator 3A 55/20 330.1 68.7 64.1
{
4 70/10 245.9 304.9 66.4 62.1 Diesel 6A 55/20 253.8 314.8 56.0 53.4 Fire Pump 7A 61/10 239.4 296.9 61.5 58.1 Ring Spray 8A 45/10 304.4 54.4 52.1 Line Break Nozzle Sp 9A 45/10 292.8 62.2 58.5 Line Break REQUIRED FLOWS 292.0 296.0 50.0 50.0
- Assumes failure of the electric fire pump and AC core spray valves All flows in gal / min NOTE: Adequate core cooling is established if either the ring spray flow is 1292 or the nozzle spray flow is > 296.
Change D describes two additions to the technical basis.
The first
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4 reiterates the fact that adequate core cooling is assured when the
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j primary core spray flow is greater than or equal to 292 gpm or the backup
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core spray flow is greater than or equal to 296 gpm.
The second addition
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-incorporates the proposed change request by adding a discussion about the
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origin of the pump curves and addresses the evaluation made of the most
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TECH SPEC CHANGE REQUEST -
4 ECCS ACCEPTANCE CRITERIA II. DISCUSSION (Continued limiting ECCS failures.
Change D also corrects a typo (gpm versus pgm)
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that was made in the bases.
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Change E deletes the monthly start test from the Fire Protection section.
This surveillance requirement was redundant to that in the ECCS section.
As discussed in Change A above, the minimum run times from this.section were added to the'ECCS section.
Change F deletes the surveillance requirement from the Fire Protection
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section which tested the automatic actuation of the system every 18
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months. The ECCS section (Tech Spec 11.4.1.4.A) currently requires
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automatic actuation of both fire pumps monthly, thus the 18 month test is
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redundant.
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With change G, the 18 month surveillance and acceptance criteria of 1000
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gpm at 110 psi associated with Tech Spec 4.7.ll.l.l.d.3 is also deleted.
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As discussed in change B and C above, the new curves provide an
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operability basis for both pumps in meeting ECCS requirements and require
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the testing each major refueling outage.
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In reviewing the Updated BRP FHSR (Section 9.5.1.2.2), Appendix A, Item t
E.2(e) of Branch Technical Position APESB 9.5-1 " Fire Protection Water Supply Systems," requires that the flow rate of the fire system be calculated on the basis of the largest expected flow rate for a period of two (2) hours, but not less than 300,000 gallons.
This flow rate should be based (conservatively) on 1,000 gpm for manual hose streams plus the greater of-i 1) all sprinkler heads opened and flowing on the largest designed fire area; or 2) the largest open head deluge system (s) operating.
At BRP, the largest open head deluge system (switchyard)~ requires 1160 gpm at 52 psig plus the 1,000 gpm for manual hose streams equates to a l
total flow of 2,160 gpm. The 300,000 gallons for two hours is equivalent to a flow rate of 2,500 gpm which is the evaluation criteria for BRP.
Using the revised fire pump head curves (Table 11.3.1.4.b), both fire pumps are capable of providing approximately 1,350 gpm at 72 psig (2,700 gpm total) which still meets the 2,500 gpm evaluation criteria.
111. ANALYSIS OF NO SIGNIFICANT HAZARDS CONSIDERATION Consumers Power Company finds, in compliance with 10 CFR 50.92(c), that the activities associated with this change request involve no significant hazards.
The following evaluation supports that conclusion.
j 1)
Will the proposed change involve a significant increase in the proubility or consequences of an accident previously evaluated?
Changer A, D, E and F are administrative in nature and do not affect
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the current extent of surveillance testing performed on the electric
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B TECH SPEC CHANGE REQUEST -
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ECCS ACCEPTANCE CRITERIA III. ANALYSIS OF NO SIGNIFICANT HAZARDS CONSIDERATION (Continued) and diesel fire pumps. As discussed above, duplication currently exists between the fire protection and ECCS sections of the Technical Specifications. With the proposed change, duplication is eliminated and the testing requirements are appropriately' located in the ECCS section.
Changes B, C and G are associated with flow testing requirements for both the electric and diesel fire pumps.
Currently testing is only required at one point (1,000 gpm, 110 psi) which is outside the operating range of the pumps when performing the ECCS function.
By requiring that pump testing encompass the complete ECCS operating range for both fire pumps, increased assurance of Loss of Coolant Accidents and Main Steam Line Breaks mitigation is realized.
By assuring that the fire pumps can perform their ECCS function and out of service (LCO's) are not being altered, the consequences of core inventory accidents are not affected. Although fires are not classified as Chapter 15 accidents, the analysis in the previous section shows that the two oumps still exceed the fire system flow requirements even though the proposed performance curves are slightly below the previous (1,000 gpm @ 110 psi) design point.
Since the proposed change only involves testing of the ECCS and fire protection pumps, and is not associated with modification to plant systems, probabilities or consequences of previously evaluated accidents remain unchanged.
2)
Will the proposed change (s) create the possibility of a new or different kind of accident from any accident previously evaluated?
The proposed changes only affect the surveillance testing program for the electric and diesel fire pumps and does not result in any change to plant systems, structures or components. Testing modes and limiting conditions for operation are also not changed, thus not creating the possibility for a different type of accident.
3)
Will the proposed change involve a significant reduction in the margin of safety?
With respect to ECCS requirements, the proposed changes add new acceptance criteria for fire pump performance, to assure that if required adequate core cooling flows of 292 gpm (primary) or 296 gpm (back-up) are achieved. Although the proposed acceptance curve.for the electric pump at the 1,000 gpm flowrate is slightly lower than previous criteria in Technical Specification 4.7.11.1.1.d.3, under LOCA/MSLB conditions the operating range is between - 100 - 750 gpm and thus does not impact ECCS performance.
For fire protection purposes the required flow rate is 2,500 gpm at 72 psig. The current acceptance criteria for both pumps results in a total flow of 3,000 gpm at 72 psig.
The new acceptance curves result in a total flow of -2,700 gpm at 72 psig which is above the required flow rate and not considered a significant reduction.
TECH SPEC CHANGE REQUEST -
6 ECCS ACCEPTANCE CRITERIA t
III. ANALYSIS OF NO SIGNIFICANT HAZARDS CONSIDERATION (Continued)
Therefore, the proposed changes do not involve a significant reduction in the margin of safety.
IV. CONCLUSION The Big Rock Point Plant Review Committee has reviewed this Technical Specification Change Request and has determined this change does not involve an unreviewed safety question and, therefore, involves no significant hazards consideration.
This change has been reviewed by the Nuclear Performance Assessment Department.
A copy of this Technical Specification Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.
P CONSUMERS POWER COMPANY i
To the best of my knowledge, information and belief, the contents of this st ittal ar truthful and complete.
By x
David P Hoffman,'Fvle-Pfesident i
Nuclear Operations i
i Sworn and subscribed to before me this 1st day of July 1993.
lSL/11L
[ SEAL]
Mv LeAnn Morse, Notary Public Berrien County, Michigan (Acting in Van Buren County)
My commission expires February 4, 1997
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