ML20141F252
| ML20141F252 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/19/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141F245 | List: |
| References | |
| NUDOCS 9705210254 | |
| Download: ML20141F252 (7) | |
Text
- _ _. --
"4 g
UNITED STATES p
g j
NUCLEAR REGULATORY COMMISSION 4
2 WASHINGTON, D.C. 20086 4001 l
\\...../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.128 TO FACILITY OPERATING LICENSE NO. NPF-2 SOUTHERN NUCLEAR OPERATING COMPANY. INC.
JOSEPH M. FARLEY NUCLEAR PLANT. UNIT 1 DOCKET NOS. 50-348 i
l.0 INTRODUCTION By letter dated December 26, 1996, Southern Nuclear Operating Company, Inc.
(SNC) et al., submitted a technical specification (TS) amendment request for l
Farley Unit I for implementation of a voltage-based alternate repair criteria in accordance with Generic Letter 95-05. As part of this amendment request, SNC proposed to increase the allowable primary-to-secondary leakage induced by a main steamline break (MSLB) accident from a previously approved value of 11.4 gallons per minute (gpm) to 20 gpm. Subsequent discussions indicated i
that the dose results presented by SNC were inconsistent with the calculations performed by the staff. Consequently, the voltage-based repair criteria amendment was approved but without an increase in the allowable event induced primary-to-secondary leakage of 11.4 gpm. The staff indicated to SNC that if they wished to increase the allowable leakage limit to a value greater than the 11.4 gpg then a revision to the TS for specific activity levels of dose equivalent I would be required.
3 By letter dated March 25, 1997, SNC submitted a request for changes to the Joseph M. Farley Nuclear Plant, Unit 1, Technical Specifications (TS). The requested changes would revise TS 3/4.4.9, " Specific Activity," and the associated Bases to reduce the limit associated with dose equivalent iodine-131. The steady-state dose equivalent iodine-131 limit would be reduced by 40 percent from 0.5 pCi/ gram to 0.3 pCi/ gram and the maximum i
instantaneous value would be reduced by 40 percent from 30 pCi/ gram to 18 q-pCi/ gram.
l 2.0 Backaround t
By letter dated June 4,1992, SNC submitted an assessment of the ragiological dose consequences of an MSLB accident. Based upon dose equivalent
'I levels of 1 pC1/ gram in primary coolant for the accident initiated spike case and 60 pCi/ gram in primary coolant for the pre-existing spike case, SNC detemined t
that the maximum allowable event induced leakage was 5.7 gpe.
In its letter dated July 29, 1993, SNC progsed that the allowable levels for specific activity of dose equivalent I for primary coolant be decreased by a factor of 4.
Such a decrease would support a factor of 4 increase in the allowable MSLB induced primary-to-secondary leakage because SNC had concluded that the geressed leakage would be offset by the reduced TS limits for dese equivalent i
I.
By letter dated April 5,1994, the staff issued Amendment No.106 to the Farley Unit 1 TSs, which reduced the allowable activity level of 1
i 9705210254 970519 PDR ADOCK 05000348 P
PDR I-
dose equivalent *I to 0.25 pCi/ gram for the 48-hour TS value and to
(
15 pCi/ gram for the maximum instantaneous value. Associated with these primary coolant activity levels was an event induced allowable primary to i
secondary leakage rate of 22.8 gpe.
i By letter dated May 31, 1995, SNCrequestedaTSamepnttoincreasethe l
primary coolant activity levels for dose equivalent I to 0.5 pCi/ gram for i
the 48-hour value and to 30 #Ci/ gram for the maximum instantaneous value.
1 1
Associated with this increase in coolant levels was a decrease in the allowable primary-to-secondary leakage induced by an MSLB. The acceptable 1
value was now 11.4 gpm.
g In its submittal dated December 26, 1996, SNC proposed to increase-the allowable primary-to-secondary leakage induced by the MSLB to 20 gpm. No corresponding decrease in the allowable levels of primary coolant activity was proposed in this letter. The staff's confirmatory calculations showed that i
the dose consequences associated with this increased primary-to-secondary leak rate would be unacceptable gi,thout some corresponding decrease in the activity
)
levels for dose equivalent I.
In a submittal dated March 25, 1997, SNC proposedtodecrgsetheprimarycoolantactivitylevelsto0.3pCi/gramof dose equivalent I for the 48-hour value and to 18 pCi/ gram for the maximum instantaneous value submittal. Associated with these activity levels was a proposed allowable primary-to-secondary leakage rate of 19 gpm.
In a submittal dated March 7,1997, SNC included its calculations to support the 20 gpa primary-to-secondary event induced leakage rate. No calculations were included in the submittal dated March 25, 1997.
Assessment of Radioloaical Consecuences The staff assessed the radiological dose consequences of an MSLB accident which induces a 19 gpm primary-to-secondary leak ang' occurs a.t primary coolant activity levels of 0.3 pCi/ gram of dose equivalent I for the accident i
initiatedspikecaseand18#Ci/gramforthepre-existingspikegase.
In both cases, the secondary coolant activity level of dose equivalent I was 0.1 pCi/ gram. The staff independently calculated the doses resulting from a main steamline break accident using the methodology associated with Standard Review Plan (SRP) 15.1.5, Appendix A.
Two assessments were performed. One wasbaseduponagre-existingiodinespikeactivitylevelof18#Ci/gramof j
dose equivalent I and the other was based upon an accident initiated iodine gike at a primary coolant activity level of 0.3 pCi/ gram of dose equivalent I.
The staff calculated doses for individuals located offsite at the Exclusion Area Boundary (EAB) and at the Low-Population Zone (LPZ) and onsite to the control room operator. The parameters, which were utilized in the staff's assessment, are presented in Table 1 (attached). The doses calculated j
by the staff are presented in Table 2 (attached).
E
- s.
. i I
i The staff's calculations show that the thyroid doses would be within the i
regulatory guidelines established for utilization of interim plugging criteria with the exception of the thyroid dose at the LPZ for the accident initiated spike case. For that case, the thyroid dose was found to be 10 percent greater than the guideline values. However, the doses would remain a small fraction of the limits of Part 100. The staff's calculations also show that the control room operator thyroid dose would be less than the guidelines of SRP 6.4 of NUREG-0800.
Although the calculated dose at LPZ for the accident initiated ~ spike case slightly exceeded the staff's guidelines, the dose was still within a small fraction of Part 100. Therefore, the staff concluded that SNC's proposed increaseintheMSLBinducedleakageto19gpminconjunctionwitharedugion in the TS allowable values for the maximun instantaneous dose equivalent I
and the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> value for dose equivalent n'I was acceptable. Therefore, the t
I proposed change to allow an MSLB induced primary-to-secondary leakage rate of 19 gpa is acceptable, j
With respect to the licensee's assumptions, which were included ir. its letter dated December 26, 1996, in support of the request for an allowable 20 gpm primary-to-secondary leak rate, two items need to be noted.
First, SNC's calculations included a control room pressurization flow of 450 cfs. That flowrate is outside the limits established in Farley Unit 1, TS 3/4.7.7.
Either SNC's calculations of record need to change to incorporate a value consistent to that allowed by the TSs or the TS's flowratg needs to be changed. SNC assumed a control room volume of 114,000 ft, which is nearly twice the volume presented in the updated Final Safety Analysis Report (FSAR).
The results presented in Table 2 incorporate a flowrate consistent with the Farley Unit 1 TSs and a control room volume consistent with the data from the updated FSAR.
3.0 STATECONSULTATION In accordance with the Commission's regulations, the State of Alabama official was notified of the proposed issuance of the amendments. The State official l
had no comments.
4.0 ENVIROMENTAL CONSIDERATION The amendment changes a requirement with respect to ;r.::ta11ation or use of a facility component located within the restricted area as oefined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be. released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (C2 FR 16201 dated April 4, 1997).
Ac.cordingly, the amendment meets the eligibility criteria for categorical exclusion set forti. In 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in i
connection with the issuance of the amendment.
j l
A
~
i (
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, j
that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common 4
defense and security or to the health and safety of the public.
Attachment:
Tables I and 2 Principal Contributor:
J. Hayes Date:
May 19,1997 i
i
. ~ -
1 TABLE 1 INPtTT PARAMETERS FOR FARLEY UNIT 1 EVALUATION OF MAIN STEAMLINE BREAK ACCIDENT
)
1.
Primary coolant concentration of 18 yC1/g of dose equivalent '3'I.
Pre-existina Snike Value (sci /a) 13.9
'3'
~
- I
=
I 4.98
=
'33I 22.2
- I 3.36
=
'33 I 12.2
=
2.
Volume of primary coolant and secondary coolant.
3 10,710 Primary Coolant Volume (ft ) *F)
Primary Coolant Temperature (
578 3
Secondary Coolant Steam Volume (ft )
3,742 3
Secondary Coolant Liquid Volume (ft )*F) 2,016 Secondary Coolant Steam Temperature (
518 Secondary Coolant Feedwater Temperature (*F) 437 3.
TS limits for DE '3'I in the primary and secondary coolant.
Primary Coolant DE '3'gconcentration (gCi/g) 0.3 Secondary Coolant DE I concentration (pci/g) 0.1 j
4.
TS value for the primary to secondary leak rate.
Primary to secondary leak rate, any SG (gpd) 140 Primary to secondary leak rate, total all SGs (gpd) 420 5.
Naximum primary to secondary leak rate to the faulted and' intact SGs.
Faulted SG (gpm) 19 Intact SGs (gpm/SG) 0.1 6.
Iodine Partition Factor Faulted SG 1
Intact SG 0.1 Primary to Secondary Leakage 1.0 i
TABLE I (continued) 7.
. Steam Released to the environment Faulted SG (lbs/2 hours) 96,200 plus primary to secondary leakage Intact SGs (lbs/2 hours) 479,000 plus primary to secondary leakage 8.
Letdown Flow Rate (gpm) 60 9.
Release Rate for 0.3 pCi/g of Dose Equivalent '3'I f.ilh.C
I 2.4 132 1
5.4
'33
' 1 5.8 I
8.5
'33 1
5.8 10.
Atmospheric Dispersion Factors EAB (0-2 hours) 6.4 x 10
LPZ (0-8 hours) 1.0 x 10
Control Room (0-8 hours) 3.3 x 10'3 i
11.
Control Room 3
Volume (ft )
69,000 Normal Makeup Flow (cfm) 1,350 Emergency Makeup Flow (cfm) 270 Makeup Filter efficiency (%)
99 Unfiltered Inleakage (cfm) 10 Recirculation Filter Flow Rate (cfm) 2,700 Recirculation Filter Efficiency (%)
95 l
i
~ - -
TABLE 2 MAIN STEAMLINE BREAK THYROID 00$E ASSESSNENT FOR FARLEY UNIT 1 Pre-existina Soike 18B LEZ Control Room Calculated doses (rem) 27 15 2.3 Regulatory Guidelines 30 30 30 (rem)
. Accident Initiated Soike 16B 12Z Control Roou Calculated doses (rem) 15 34 5.0 Regulatory Guidelines 30 30 30 (rem) 1 I