ML20073H666
| ML20073H666 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 04/28/1991 |
| From: | Starkey R CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML19298E451 | List: |
| References | |
| NLS-91-122, NUDOCS 9105070223 | |
| Download: ML20073H666 (8) | |
Text
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Cp&L Carolina Power & Light Company T
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April 28, 1991 a
1 SERIAL: NLS 91 122 10CFR50.90 United States Nuclear Regulatory Commission ATTENTION: Document: Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT,~ UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 & 50 324/ LICENSE NOS. DPR 71 & DPR-62 h
SUPPLEMENT TO REQUEST FOR TEMPORARY WAIVER OF COMPLIANCE REACTOR WATER CLEANUP SYSTEM DIFFERENTIAL FLOW ISOLATION INSTRUMENT
- Centlemen:
L
'By letter dated April 26, 1991 (Serial:1NLS 91 118), Carolina Power &_ Light i
Company _ requested'a temporary NRR Waiver of. Compliance for the Brunswick Steam
-Electric Plant, Units-1 and 2.
The proposed-waiver applies to the. reactor water cleanup system differential flow isolation actuation-instrument trip setpoint and allowable value specified:in Technical Specification Table'3.3,2 2, Item 3.a.
. Carolina Power & Light Company is continuing to
. prepare an emergency-license amendment request to revise >the reactor water
- cleanup' system. differential-flow isolation actuation trip setpoint and allowable value.
-DuringLsubsequent telephone discussions,on Apri1L-26,-1991_with the Nuclear Regulatory Commission-(NRC) concernin5 the submittal, the NRC1 Staff = identified =
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=several'issuos relating to;the supporting technical analysis-for-the waiver:
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request. 'These issues,-and the Company's responses, are provided in.-
Revised pages'for General Electric Report CE NE-901 011 0391:are' provided.Lin Enclosure 2..
q LThe' Company' would like : to note the April'26, l1991. waiver of _ compliance request -
incorrectlytrefers to the-reactor. vater _ cleanup' system differential: flow isolation actuation' function as Item-2.a of Technical Specification
= Table 3.3.2-2..
The correct Lreference for-the - reactor water cleanup system differential flow function-is-Item 3.a.of Table 3-3.2 2.
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-On the-I ts of the information provided in our submittal dated April-26, 1991 and the.-
iformation herein, Carolina Power & Light Company requests this
.temporar,; waiver until such timecasithe-NEC is able to review and approve'an emergency license _ amendment request. -In order to avoid the delay of the'.
t start up'of Brunswick Units.:1 and 2',~CP&L now requ'ests'that this waiver of-tcompliance;be Branted prior to 1600 on: April 29,- 1991.
The' Plant Nuclear-Safety Committee'has-' reviewed and: approved submittal'of the information
- provided herein _
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Document Control Desk NLS 91 122 / Page 2 Please refer any questions regarding this submittal to Mr. K. J. Ahern at
- (919) 457 2404.
Yours very truly, h'hh'Y[LR
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R. B.-Starke Vice President Brunswick Nuclear Project RBS/k'RM/wrin (rwcuwav2,vpf)
- Enclosure cc:
Mr. Dayne H. Brown Mr. S. D. Ebneter Mr. N. B. 1.e Mr. R.
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ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50 325 6 50 324 OPERATING LICENSE NOS. DPR 71 6 DPR 62 SUPPLEMENT TO REQUEST FOR TEMPORARY WAIVER OF COMPLIANCE REACTOR WATER CLEANUP SYSTEM DIFFERENTIAL FLOW ISOLATION INSTRUMENT NRC'Ouestion 1:
Provide all major assumptions and associated technical bases (or references thereto) used in the dose consequences calculations, the results of which are summarized in a report prepared by Cencral Electric (General Electric Report GE NE 901 011 0391).
CP&L Response:
The General Electric calculation provides a conservative analysis of the dose consequences for'the reactor water cleanup system cold water rupture accident.
The cold water rupture accident encompasses a postulated line break downstream of the reactor water cleanup system heat exchaigers, but upstream of the filter domineralizers.
For postulated reactor water cleanup system line breaks upstream of the heat exchanger or for a postulated line break dovnstream of the_ heat exchangers where the heat exchangers are unable to maintain water temperature below 200 degrees F, such breaks are adequately detected and miti ated by existing area temperature monitors that provide 6
reactor water cleanup system isolation (refer to Technical Specification Table 3.3.2-2, Items 3 b and 3.c).
The following assumptions were used by General Electric in performing the dose consequence analysis for a cold water pipe rupture of the reactor water cleanup system outside of primary containment:
Water temperature: 140 to 160 degrees Fahrenheit. -operation of the reactor water cleanup system resin bed filters-is limited to less than these temperatures, else damage to the: resin beds will occur.
The standby gas treatment system is assumed to be available and.in service. This is based on Technical Specification requirements that the-standby gas treatment system be operable when the plant is in Operational Conditions 1, 2, or 3 (Technical Specification 3/4,6.6.1).
The standby gas treatment system filter efficiency is assumed to be
- 99. percent. This is based on the Technical Specification requirement to demonstrate filter efficiency to be at least 99 percent (Technical Specifications 4.6.6.1.c and 4.6.6.1.f),
Reactor coolant system activity: 0.2.microcuries per gram dose equivalent I 131.. This is based on the-allowable reactor coolant system activity value specified in the Technical Specifications during normal plant operation (Technical Specification 3/4.4.5).
The fraction of released reactor coolant system activity that is assumed to becomeLairborne is 2 percent.
This is based on this analysis applying to a cold wate, pipe break and associated General Electric enthalpy calculations.
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8 Breathing rate: 3,47 E 4 m / secs at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
This is an accepted standard value, X/Q values for the low population area:
8 0 to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s:
4,8 E 5 secs /m 3
8 to 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
3.3 E 5 secs /m 3
1 to 4 days:
1,4 E 5 secs /m 3
4 to 30 days:
4.1 E 6 secs /m 3
X/Q value for the exclusion aret.: 4,3 E 4 secs /m for 0 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
Control room infiltration:
0.043 m?/sec j
3 Control room filter inleakage: 0 m /see i
control room volume:
9741 m3 3
Control room recirculation flow through filter:
14.3 m /sec Control room filter efficiency:
95 percent Control room dose X/Q assumptions:
3 0 to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s:
3.5 E 3 secs /m 3
8 to 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
2.1 E 3 secs /m 3
1 to 4 days:
1.1 E 3 secs /m 3
4-to 30 days:
2.3 E 4 secs /m The General Electric X/Q values cited above are conservatively based on a ground level releaso; however,. based on the standby gas treatment system being in service, the actual release would be an elevated release through the plant stack. Where appropriate, General Electric Report GE NE-901 011 0391 has been revised to clarify certain of the assumptiono provided above. The revisions to General Report GE NE 901 011-0391 are provided in Enclosure 2, Carolina Power & Light has reviewed the assumptions of the General Electric calculations.
The General Electric report uses assumed conditions based on a
" reference plant."
In most cases, the General Electric assumptions are identical to or bounded by the same parameters for the Brunswick Plant except
-for.the assumed values for control room inleakage.-size, and recirculation flow.. A comparison of the differences in the General Electric assumptions and the Brunswick Plant values;is provided below:
X/Q values for the low population area:
GE Value Brunswick Value 3
3 O to 8-hours:-
4.8 E 5 secs /m 8.8 E-6 secs /m 8-3
'8 to 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
3,3 E 5 secs /m 3.8 E 6 secs /m 3
3 1 to 4 days:
1.4 E 5 secs /m -
1,0 E 6 secs /m -
4 to 30 days:
4.1 E 6 secs /m 3,5 E-7 secs /m3 3
The Brunswick Plant values are documented in the Updated Final Safety Analysis Report, Table 2.3.4 15.
The values for~ stack release are used' based on the assumption that the standby gas treatment system is available and in service (thus resulting in an elevated release via the
. plant stack).
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a X/Q valve for the exclusion area:
OE Value Brunswick Value 8
3 O to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s:
4.3 E.4 secs /m 2.0 E.5 secs /m The Brunswick Plant value-is documented in the Updated Final Safety Analysis Report, Table 2.3.4 15.
The Brunswick Plant value is for an elevated (plant stack) release based on the assumption that the standby gas treatment system is available and in service.
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X/Q for the control room:
CE Value Brunswick Value 3
3 0 to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s:
3.5 E 3 secs /m 3.3 E 4 secs /m (0 1/2 hour)3 to 1.8 E.6 secs /m (1/2 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) 3 3
8 to 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
2.1 E 3 secs /m 1.1 E.6 secs /m 3
3 1 to 4 days:
1.1 E 3 secs /m 2.0 E 7 secs /m 3
3 4 to.30 days:
2.3 E 4 secs /m 2.7 E.8 secs /m
..The Brunswick Plant values are documented in a report tit ed " Control l
Room Habitability Evaluation, Brunswick Steam Electric Plant, (NRC TMI Action' Plan Item III.D.3.4)," Revision 2 NUS Report NUS-3697. The conclusions of this. report were accepted by the NRC by letter and Safety Evaluation dated February 16, 1989 (NRC TAC Nos, 57421 and 57422).
Control room habitability parameters:
CE Value Brunswick Value 8
3 Control room infiltration:
0.043 m /sec 0.129 m /sec
- Control room 3
3 filter inleakage:
O m /sec 0.010 m /sec Control-room' volume:
9741 m3 8362.m3 Control room-recirculation 3
3 Eflow'through filter:
14,3 m /sec 0,933 m /see control room filter efficiency:
95 percent 95 percent elemental-
-95_ percent particulate 90 percent organic The. Brunswick Plant values are documented in a report titled " Control Room _ Habitability Evaluation, Brunswick Steam Electric Plant, (NRC TMI Action Plan Item III.D.3.4)," Revision 2, NUS Report NUS 3697.
The conclusions of'this report were accepted-by-the NRC by letter and Safety Evaluation dated February. 16, 1989 (NRC TAC Nos, 57421 and 57422).
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At the request of Carolina Power 6 Light Company, General Electric performed a revised analysis using input parameters that are either equal to or more limiting'than actual Brunswick Plant values.
The Brunswick-specific input parameters used for this analysis are as follows:
3 3
Control room unfiltered inleakage:
276 f t / min (0,129 m /sec)
Control room volume:
8362 m3 3
Control room recirculation flow through filter: 0,933 m /see Control room filter efficiency:
95 percent X/Q for the control room:
3 0 to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s:
3.3 E 4 secs /m 3
8 to 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
1.1 E 6 secs /m 3
1 to 4 days:
2.0 E 7 secs /m 3
4 to 30 days:
2,7 E 8 secs /m The General Oloctric's Brunswick-specific analysis results in control room dose consequences that are bounded by General Electric's reference plant analysis and which are significantly below the applicable regulatory limits (10 CFR 100 and 10 CFR 20 for offsite doses; 10 CFR 50, Appendix A, General Design Criterion 19 and Standard Review Plan Section 6,4 for control room doses). These results are summarized and compared with both the General Electric reference plant results and applicable regulatory limit below:
Regulatory GE Reference Brunswick Limit Plant Result R 3 It Control room, thyroid 30 rem 0,095 rem 0.0:.5 rem Control room, whole body 5 rem negligible negligible
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Based on a review of this information, the Company has determined that the General Electric calculations and dose consequences bound those that would be obtained using completely Brunswick specific input parameters. Therefore, the Company believes that based on the proposed change to the trip setpoint and allowable value for the reactor water cleanup system differential flow isolation actuation instrument from "less than or equal to 53 gpm" to "less than or. equal to 125 gpm", the Brunswick offsite and control room dose consequences for a postulated reactor water cleanup system cold water break accident would not exceed the regulatory limits of 10 CFR 100 and 10 CFR 20.
NRC Ouestion 2:
For the offsite and control-room dose calculations, clarify what portion of coolant activity is assumed to becoce airborne activity.
CP&L Response:
According to Ceneral Electric, an enthalpy balance calculation was used to determine the percentage of fluid mass that will vaporize when released to the ambient environment based on the pressure and temperature of the reactor water cleanup system fluid within the piping system.
The resulting ratio was then applied to coolant released to establish the percentage of coolant activity that becomes airborne activity. General Electric selected the 2 percent value based on calculations that show the actual airborne fraction value for initial El-4
reactor water. cleanup system conditions of 1050 psia and 160 degrees Fahrenhe,it to be less than the 2 percent value.
NRC Ouestion 3:
In General Electric Report GE NE-901 011-0391, the analysis results summarized on page 8 are provided in units of millirem.
Verify whether these dose results are in terms of millirem or in terms of rem.
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CP&L Resoonse:
-l The dose results provided in the General Electric report are correct (i.e.,
the resulting doses are in terms of millirem),
NRC Ouestion 4:
Based on the responses to the questions described above, re affirm that the conclusions of the significant hazards analysis provided in your April 26, 1991 submittal remain valid.
CP&L Response:
Carolina power 6 Light Company has re evaluated the requested temporary waiver of compliance based on the additional information provided by General Electric Company and summarized herein.
As discussed in the response to NRC Question 1 above, Carolina Power & Light has reviewed the assumptions of the General Electric calculations. 'In most cases, the General Electric assumptions which are derived'from a GE " reference plant" are identical to or bounded by the same parameters for the Brunswick Plant except for the assumed values for control room inleakage and size.
The Company has assessed the significance of these differences and, based on a further General Electric evaluation using plant-specific parameters, determined that the General Electric calculation results provide an adequate basis for concluding that the consequnces of-the proposed change to reactor water cleanup system differential flow isolation
-actuation trip setpoint and allowable value described in the temporary waiver of compliance does not involve a significant hazards consideration and-that the conclusions of the significant hazards analysis provided in our April 26, 1991 submittal remain valid.
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ENCLOSURE 2 BRUNSWICK STEAM ELECTRIC PIANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 6 50 324 OPERATING LICENSE NOS. DPR 71 6 DPR 62 SUPPLEMENT TO REQUEST FOR TEMPORARY WAIVER OF COMPLIANCE REACTOR WATER CLEANUP SYSTEM DIFFERENTIAL FLOW ISOLATION INSTRUMENT REVISED PAGES FOR GENERAL ELECTRIC REPORT GE NE 901-011 0391 i
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