ML20198R522

Safety Evaluation Supporting Amends 132 & 124 to Licenses NPF-02 & NPF-08,respectively

ML20198R522
Person / Time
Site:	Farley
Issue date:	10/29/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20198R489	List: ML20198R483 ML20198R518 ML20198R522
References
NUDOCS 9711130303
Download: ML20198R522 (6)

Text

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g..%k y UNITED STATES s

NUCLEAR REGULATORY COMMISSION  !

o WASHINGTON, D.C. tam 4e01

%,, o ne**  !

SAFETY EVALUATION BY THE OFFICE OF NbCL FAR REACTOR REGULATION RELATED TO AMENrmaENT NO.132 TO FACILITY OPERATING LICENSE NO. NPF-2  !

AND AMENDMENT NO.124 TO FACILITY OPERATING LICENSE NO. NPF-8  !

SOUTHERN NUCLEAR OPERATING COMPANY. INC.. ET AL.

JOSEPH M. FARLEY NUCl FAR PLANT. UNITS 1 AND 2 POCKET NOS. 50-348 AND 50 364 >

1.0 INTRODUCTION

By letter dated September 17,1997, the Southem Nuclear Operating Company, Inc. (Southom Nuclear), et al., submitted an amendment request to modify the Joseph M. Feriey Nuclear  :

Plant, Units 1 and 2, Technical Specifications (TSs). The roquested changes would revise TS 3/4.4.g, " Specific Activity," to reduce both the maximum instantaneous and the 48-hour values of dose equivalent "'I (iodine 131) in the reactor coolant. Southem Nuclear proposed to reduce these values because of the determination of an increase in the allowable primary-to-secondary leakage associated with a main steamline break (MSLB) accident. This increase was from a previously approved value of ig gallons per minute (gpm) (density corrected to 13.5 gpm) for Unit 1 and 11.4 gpm (not density corrected) for Unit 2 to a density corrected value ,

of 23.8 gpm for both,

2.0 BACKGROUND

in Amendment No.128 to the Unit 1 TSs, the 48-hour specific activity level of dose equivalent

"'I was changed to 0.3 microcurie / gram (pCl/g) from the previously appros ad va'ue of 0.5 pCilg. In addition, Table 4.4-4 was changed to require sampling of "'t, '"I, and '"i overy 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when the specific activity level of primary coolant exceeded 0.3 pCilg. Figure 3,4-1 was changed to limit the maximum instantaneous activity level of dose equivalent "'l at rated thermal power levels of 80% or greater to 18 pCilg.

In Amerx mont No.106 to the Unit 2 TSs, the 48-hour specific activity level of dose equivalent

"'l was changed to 0.5 pCL/g from the previously approved value of 1.0 pCL/g. In addition, Table 4.4-4 was changed to require sampling of "'l, '"I, and '"I every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when the -

specific activity level of primary coolant exceeds 0.5 pCilg. Figure 3.4-1 was changed to limit -

the maximum instantaneous activity level of dose equivalent "'l at rated thermal power levels of 80% or greater to 30 pCilg. This was a decrease from the previous value of 60 pCilg. The Bases section of the TS was also changed to reflect the new value of 0.5 pCL/g.

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2-A letter dated July 30,1907, from the Nuclear Energy institute to the industry indicated that a '

licensee had determined that some alle-allowable MSLB steam generator leak rates and the end of cycle (EOC) MSLB leak rates were incompatible because these values had not compensated for density differences. When this issue was reviewed for Farley Unit 1, it was determined that, for Amendment No.128, the approved 19 gpm leak rate actually corresponded to a 13.5 gpm leak rate when compensated for density. The results of the spring 1997 inspection of the Unit 1 steam generators indicated that the maximum projected EOC leak rate for the current operating cycle would be 15.7 gpm, which exceeded the projected EOC leakage

• of 13.7 gpm approved in Amendment No.128. The licensee projected the 13.7 gpm leak rate l would be exceeded 310 effective full power days into the present operating cycle. As of September 12,1997, Unit 1 was 100 days into the cycle.

• During this same spring 1997 steam generator inspection, a 13.7 volt indication was discovered in the 1C steam generator at the first tube suppori plate. This was considered to be a significant finding with respect to the existing data base for altomate repair criteria at the tube support plate. In-situ testing of the tube revealed no leakage at the MSLB differential pressure.

However, the tube was subsequently pulled, tested, and destructively examined. The MSLB 4 leakage for this intersection was determined to be 0.72 gpm. When this data is added to the currently approved voltage versus burst correlation and the voltage versus MSLB leakage correlation, there is a significant impact on the projected calculated EOC leakage. The new EOC calculated leakage was determined to be 20.4 gpm and the present condition of the Unit 1  ;

steam generators is such that the approved leakage in Amendment No.128 is exceeded. '

Consequently, the licensee placed an administration limit on the 48-hour TS value of dose equivalent

• I of 0,15 pCilg. ,

in a letter dated September 17,1997, Southem Nuclear submitted an amendment request that proposed to modify TS 3/4.4.9, " Specific Activity," for both Units 1 and 2. In this letter, ,

Southem Nuclear proposed to reduce the 48-hour TS value of dose equivalent *l from O.3 pCi/g to 0.15 pCilg and the maximum instantaneous value in the 804100% power range r from 18 pCl/g to 9 pCL/g. The maximum instantaneous values for power levels less than 80%

would also be reduced in Figure 3/41. Associated with these reductions in allowable values of dose equivalent *l in primary coolant was a proposed increase in the allowable primary to-secondary leakage rate to 23.8 gpm.

Assenament of Radiological Consequences The staff assessed the radiological dose consequences of an MSLB accident, which incorporates a density corrected 23.8 gpm primary-to-secondary leak. Two cases were evaluated. The first involved the accident initiated spike case, which is presumed to occur at the proposed 48-hour TS value of dose equivalent *l in primary coolant,0.15 pCilg. The second case involved the preexisting spike case, which is presumed to occur at the maximum instantaneous value of dose equivalent *l for 80% power or greater,9 pCl/g. In botil cases, the secondary coolant activity level of dose equivalent *l was 0.1 pCilg. The staff independently calculated the doses resulting from a main steamline break accident using the  ;

methodology associated with Standard Review Plan 15.1.5, Appendix A.

l

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i The staff calculated doses for individuals located offsite at the Exclusion Area Boundary and at the Low-Population Zone and onsite to the control room operato(. The perameters, which were '!

' utilized in the staffs assessment, are presented in Table 1 (attached). The dows calculated by

, the staff are presented in Table 2 (attached).

l

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The staffs calculations showed that the thyroid doses would be within the regulatory guidelines established for utilization of interim plugging criteria. Consequently, the staff concluded that the licensee's proposed increase in the MSLB induced leakage to a density compensated 23.8 gpm  :'

in conjunction with a reduction in the TS allowable values for the maximum instantaneous dose equivalent "'l and the 48-hour value for dose equivalent "'l would be acceptable. Therefore, the proposed change to allow a total primary-to secondary leakage rate of 23.8 gpm for an -  !

MSLB is acceptable.

3.0 STATE CONSULTATION

in accordance with the Commission's regulations, the State of Alabama official was notifed of the proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve 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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 49998 dated September 24, igg 7). Accordingly, the

- amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(g). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.

Attachment:

Tables 1 and 2 Principal Contributor: J. Hayes Date: October 29, 1997

TABLE 1 ,

INPUT PARAMETERS FOR FARLEY UNITS 1 AND 2 EVALUATION OF MAIN STEAMLINE BREAK ACCIDENT

1. Primary coolant concentration of 9 pCilg of dose equivalent "'t.

Preexistina Soike Value (uCl/a)

^

"'I = 6.95 "21 = 2.49

"'I = 11.1 -

"'I = 1.68 "Si = 6.1 i

2. Volume of primary coolant and secondary coolant.

i Primary Coolant Volume (ft') 10,710 Primary Coolant Temperature ('F) 578 Secondary Coolant Steam Volume (ft') 3,742 Secondary Coolant Liquid Volume (ft') 2,016 Secondary Coolant Steam Temperature ('F) 518 Secondary Coolant Feedwater Temperature ('F) 437

3. TS limits for DE "'I in the primary and secondary coolant.

Primary Coolant DE "'l concentration (pCl/g) 0.15 Secondary Coolant DE "'l concentration (pCl/g) 0.1

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. Maximum primary to secondary leak rate to the faulted and intact SGs.

Faulted SG (gpm) 23.8 Intact SGs (gpm/SG) 0.1

6. lodine Partition Factor Faulted SG 1 Intact SG 0.1 Primary to Secondary Leakage 1.0

7. Steam Released to the environment Faulted SG (Ib/2 hours) 96,200 plus primary-to-secondary leakage intact SCs (Ib/2 hours) 479,000 plus primary to-secondary leakage Attachment i

, as o 2-P

8. Letdown Flow Rate (gpm) 60

9. Release Rate for 0.15 pCl/g of Dose Equivalent *l Gbt

• l = 1.2

• l = 2.7

• l = 2.9

• l = 4.2 51 = 2.9

10. Atmospheric Dispersion Factors (sec/m')

EAB (0-2 hours) 6.4 x 104 LPZ (0-8 houm) 1.0 x 10d Control Room (0-8 hours) 3.3 x 104

11. Control Room Volume (ft') 69,000 Normal Makeup Flow (cfm) 1,350 Emergency Makeup Flow (cfm) 270 Makeup Finer efficiency (%) 99 Unfinered Inleakage (cfm) 10 Recirculation Finer Flow Rate (cfm) 2,700 Recirculation Finer Ef5ciency (%) 95

, .w o TABLE 2 l

MAIN STEAMLINE BREAK THYROID DOSE ASSESSMENT FOR FARLEY UNITS 1 AND 2 Preexistina Soike Exclusion Low. Control Room Area Population i Boundarv ZDat Calculated doses (rem) 23.8 13.2 2.0 Regulatory Guidelines (rem) 30 30 30 Accident initiated Soike Exclusior. Low. Control Roorm Area Population l Boundary ZDDR Calculated doses (rem) 13.2 29.8 4A Regul& tory Guidelines (rem) 30 30 30 t

i Attachment 2

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