ML18039A249
| ML18039A249 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 02/18/1998 |
| From: | De Agazio A NRC (Affiliation Not Assigned) |
| To: | Zeringue O TENNESSEE VALLEY AUTHORITY |
| References | |
| TAC-M83348, TAC-M83349, TAC-M83350, TAC-M99711, TAC-M99712, NUDOCS 9802250060 | |
| Download: ML18039A249 (6) | |
Text
Mr. O. J. Zeringue Chief Nuclear Officer and Executive Vice President Tennesse'e Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801 Fe ary 18, 1998
SUBJECT:
BROWNS FERRY PLANT UNITS 2, AND3-REQUEST FOR ADDITIONAL INFORMATIONREGARDING TECHNICALSPECIFICATION CHANGE TS-384 REQUEST FOR LICENSE AMENDMENTFOR POWER UPRATE OPERATION (TAC NOS. M99711 AND M99712) AND RESOLUTION OF CONTROL ROOM EMERGENCY VENTILATIONSYSTEM ISSUES (TAC NOS. M83348, M83349, AND M83350)
Dear Mr. Zeringue:
By letter dated October 1, 1997, Tennessee Valley Authority (TVA)proposed revisions to the Browns Ferry Nuclear Plant, Units 2 and 3 Technical Specifications to permit operation of the units at the uprated power level of 3458 MWt. On July 31, 1992, TVAsubmitted the corrective actions to be implemented to resolve the identified deficiencies in the Control Room Emergency Ventilation System (CREVS), and TVA's letter of August 10, 1994, described the methodology used to determine atmospheric dispersion used in the control room dose analysis.
The NRC staff is reviewing your amendment application and the CREVS corrective actions, and while the amendment application and the CREVS corrective actions are separate issues, the CREVS issue must be resolved in order to complete the review of the power uprate application. The staff has determined that additional information is required to complete these reviews.
A description of the information required is provided in the enclosure.
Please provide the requested information by March 15, 1998. Your prompt response willassist us in completing timely reviews.
Sincerely,
/s/
Albert W. De Agazio, Senior Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc: See next page Docket No. 50-260, 50-296 Serial No. BFN-98-002
Enclosure:
As stated DISTRIBUTION'UBLIC JZwolinski gp~ 0 i r
I IIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIII,'Hebdon (Docket File Q
BClayton ADeAgazio Browne Ferry r/f OGC ACRS J Jaudon, Rll OFC PDII-3/PM NAME ADeAga
. w DATE Q/g/98 PDII-3/LA BCtayto~
/
Iw /98 PERB/D
-racFL
/17i98 PDII-3/D FHebdo lg/98 OFFICIAL RECORD COPY DOCUMENT NAME: GABFN>99711RAI.WPD 9'802250060
'gi802i8 PDR ADQCK 05000260 P
PDR N~>g It'Il'Lt/F.II'~j'~V
gP,R RE00
~o Cy oO Cy
~O
++**+
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 205554001 February 18, 1998 Mr. O. J. Zeringue Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801
SUBJECT:
BROWNS FERRY PLANT UNITS 2, AND 3 - REQUEST FOR ADDITIONAL INFORMATIONREGARDING TECHNICALSPECIFICATION CHANGE TS-384 REQUEST FOR LICENSE AMENDMENTFOR POWER UPRATE OPERATION (TAC NOS. M99711 AND M99712) AND RESOLUTION OF CONTROL ROOM EMERGENCY VENTILATIONSYSTEM ISSUES (TAC NOS. 83348, M83349, AND M83350)
Dear Mr. Zeringue:
By letter dated October 1, 1997, Tennessee Valley Authority (TVA)proposed revisions to the Browns Ferry Nuclear Plant, Units 2 and 3 Technical Specifications to permit operation of the units at the uprated power level of 3458 MWt. On July 31, 1992, TVAsubmitted the corrective actions to be implemented to resolve the identified deficiencies in the Control Room Emergency Ventilation System (CREVS), and TVA's letter of August 10, 1994, described the methodology used to determine atmospheric dispersion used in the control room dose analysis.
The NRC staff is reviewing your amendment application and the CREVS corrective actions, and while the amendment application and the CREVS corrective actions are separate issues, the CREVS issue must be resolved in order to complete the review of the power uprate application. The staff has determined that additional information is required to complete these reviews.
A description of the information required is provided in the enclosure.
Please provide the requested information by March 15, 1998. Your prompt response willassist us in completing timely reviews.
Sincerely, cc: See next page Docket No. 50-260, 50-296 Serial No. BFN-98-002 Albert W. De azio, Senior Proj t
Project Dir orate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation nager
Enclosure:
As stated
Mr. O. J. Zeringue Tennessee Valley Authority BROWNS FERRY NUCLEAR PLANT CC:
Mr. J. A. Scalice, Senior Vice President Nuclear Operations Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Jack A. Bailey, Vice President Engineering 8 Technical Services Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. C. M. Crane, Site Vice President Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 General Counsel Tennessee Valley Authority ET 10H 400 West Summit Hill Drive Knoxville, TN 37902 Mr. Raul R. Baron, General Manager Nuclear Assurance Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Karl W. Singer, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 Mr. Mark J. Burzynski, Managar Nuclear Licensing Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Timothy E. Abney, Manager Licensing and Industry Affairs Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 37402-2801 Regional Administrator, Region II U.S. Nuclear Re'gulatory Commission 61 Forsyth Street, SW., Suite 23T85 Atlanta, GA 30303-3415 Mr. Leonard D. Wert Senior Resident Inspector U.S. Nuclear Regulatory Commission Browns Ferry Nuclear Plant I0833 Shaw Road Athens, AL35611 State Health Officer Alabama Dept. of Public Health 434 Monroe Street Montgomery, AL35130-170l Chairman Limestone County Commission 310 West Washington Street Athens, AL 35611
REQUEST FOR ADDITIONALINFORMATION BROWNS FERRY NUCLEAR POWER PLANTS, UNITS 2 AND 3 POWER UPRATE OPERATION (TAC NOS. M99711, M99712)
CONTROL ROOM EMERGENCY VENTILATIONSYSTEM (TAC NOS. M83348, M83349, AND M83350)
C C
S C
C 0
0 U
S 99 The October 1, 1997, submittal describes the process by which accident doses determined at the previous power level were ratioed to estimate the doses at the proposed power level ~ The staff recognizes that the increase in doses would normally be proportional to the increase in thermal power or the increase in rated steam flow. The submittal does not, however, provide sufficient information for the staff to make the findings necessary to approve the amendment.
Please refer to the radiological analysis discussions in the NRC Safety Evaluation Reports issued on the General Electric topical reports.
To facilitate the staff's review, please provide the following information:
a.
A description of the assumptions, inputs, and methodology used in each analysis.
The Final Safety Analysis Report (FSAR) descriptions, generally do not provide sufficient detail for the staff to assess the acceptability of assumptions, inputs, and methodologies used.
b.
Afi~cjgJa justification for any significant deviations from analysis guidance in applicable regulatory guides and Standard Review Plan chapters (15.x.x).
Note:
While the staff may perform confirmatory calculations, the staffs finding that offsite and control room doses are acceptable must be based on the licensee's design analyses.
This is'necessary for maintaining the plant's design basis.
The staff must review the licensee's assumptions, inputs, and methodologies in making these findings. While submittal of the actual analyses is preferable, the staff recognizes that these analyses may be considered proprietary, and will accept tabular summaries of this information. Information in the format and content shown in Table 15.4 of Regulatory Guide 1.70 would be adequate.
The October 1, 1997, power uprate submittal did not address the impact of the increased power level on the radiological consequences of postulated accidents to the control room operators.
The staff must make a finding that the postulated operator doses willcontinue to comply with 10 CFR Part 50, Appendix A, GDC-19, as clarTiied in Standard Review Plan Chapter 6.4, for all accidents.
Please submit a description of the assumptions, inputs, and methodologies used; and the obtained results of the TVAre-analysis of the control room doses.
For events that do not result in a primary containment isolation signaI, please assess the impact of delays in reaching the radiation monitor alarm set point, or time to complete operator manual isolation.
ENCLOSURE 8
8 By letter dated July 31, 1992, TVAprovided a corrective action plan to address control room habitability concerns.
This plan is still under review. Please provide a summary of the status of the items identified in the plan, e.g., which actions have been implemented and which are pending.
In addition, the staff previously was provided copies of the following analyses:
Control Room Doses, RIMS R14 92 0903 110, including attachments Control Room NQ, RIMS R14 92 0727-105 Control Room Doses from MSIV, RIMS R92 920904-001 Ifthese analyses have been updated, please provide copies (or as a minimum, a description) of the of the revision(s) to facilitate the staff's review.
TVA's letter dated August 10, 1994, explained the methodology used to determine the control room atmospheric dispersion (X/Q) values used in the dose analyses.
The staff has a concern with the extremely low values of X/Q postulated for an elevated release.
Our confirmatory analyses indicate that the postulated values may be low by as much as six orders of magnitude.
In the analysis, the distance to the closest control room emergency ventilation system (CREVS) intake (i.e., Unit 1) was used.
The Unit 3 intake, although farther away, would appear to yield the most restrictive X/Q value.
For an elevated release, the ground level concentrations increase rapidly with increasing distance until the lower surface of the plume reaches ground level due to vertical diffusion. From this point, the concentrations decrease with increasing distance.
Both CREVS intakes are within this cavity where the concentrations are increasing.
The concentrations due to fumigation may increase similarly. Please justify the values or re-assess the X/Q values used and update dose analyses accordingly.
The control room corrective action plan describes the installation of dual CREVS intakes on either side of the turbine building. FSAR Section 10.12.5.3 describes the intakes as being from the ventilation towers. This is also shown on FSAR Figure 10.12-2b.
FSAR Section 14.6.3.6 describes the configuration as described in the corrective action plan.
Please explain the differences in these system descriptions.
FSAR Figure 10.12.2a implies that the previous auxiliary pressurization fans (fans31-151, 31-152) are still available for use.
Should the 500 cfm flowof these fans be considered with the 3000 cfm of the 31-7213 or 31-7214 fans'? This drawing indicates that the normal supply to the two control rooms to be 12100 cfm and 7225 cfm. What portion of these flows is attributable to outside air makeup (prior to isolation)'?
The loss-of-coolant accident (LOCA) analysis for control room dose assumes mixing and dilution in the base of the stack for a ground level release for certain leakage paths.
A review of elevation and plan drawings of this area indicate the possibility of leakage plumes-from the release point to the louvers in the stack walls affording little or no mixing.
There does not appear to be sufficient internal structures in this area to justify the assumption of complete and timely mixing. Please provide a justification for this assumption.
C 0
T FSAR text indicates that two SGTS trains can maintain the secondary containment at a negative pressure except for a short period at the beginning of a LOCA.
There are three Standby Gas Treatment System (SGTS) trains, but only two emergency power trains.
Please explain assumption that two SGTS trains would be available given a single failure of one emergency power train. Does the third SGTS train transfer automatically to the energized emergency bus, or is manual operator action necessanf?
Based on the emergency operating procedures, how long would it take for the second train to be energized'?
What is the differential pressure status of the secondary containment during this period' b.
Is the drawdown time for the secondary containment, with the various combinations of SGTS trains, measured periodically'? Ifnot, what is basis for FSAR conclusion that the drawdown time is negligible'? During periods of high exterior winds' The analyses appear to take credit for 90% filtration for both organic and non-organic iodine species.
The Browns Ferry Nuclear Plant technical specification test acceptance criteria for methyl iodine is 10% penetration or bypass.
This acceptance criteria does not support the assumed filtration credit. Standard technical specifications require the application of a safety factor to account for filter media degradation between tests.
This factor is 5 for systems with heaters and 7 for systems without heaters.
To assume 90%
credit, the penetration or bypass fraction for filters with heaters must be less than 2%.
Please provide a technical justification supporting the assumed filtration credit.