ML20069Q338
| ML20069Q338 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/09/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20069Q336 | List: |
| References | |
| NUDOCS 9101150274 | |
| Download: ML20069Q338 (3) | |
Text
.-
. ~ _ - -. - -. - - - -.
1 -
i EQClop l*
+f
',o.,
UNITED STATES NUCLEAR REGULATORY v)MMISSION n
5 I*
W ASHINGTON. 01 20668
\\..... /'
ENCLOSURE 3 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.186 TO FACILITY OPERATING LICENSE NO. DPR-52
~
AMENDMENMO,.150 TO FACILITY OPERATING LICENSE NO. DPR-68 TENNESSEE VALLEY AUTHORITY BPOWNS F,ERRY NUCLEAR PLANT. UNITS 2 AND 3 DOCKET NOS. 50-260 AND 50-296 1.0 INTRODUCTIp Prowns Ferry Units 2 and 3 share certein plant systems including the emergency dieselgenerators(EDG). Specificelly the three Unit 3 support Unit 2 by providing a source of emergency power. EDG's are required to The technical speci-fications for Units 2 and 3 are required to be changed to reflect the plant l
configuration whercin some trains and subsystems of specific systems that are shared by all three Units are provided standby powe" by the Unit 3 EDGs.
By letter dated December 21, 1989, the staff requested TVA to revise Unit 2 Technical Specifications prior to restart to specifically include operability requirements for the Unit 3 EDGs to support Unit 2.
2.0 EVALUATION Analysis The change to the Unit 2 and Unit 3 Technical Specifications reflects the requirement that the Unit 3 EDGs must be operable to support equipment for Unit 2 operation. EDG 30 provides emergency power to t1e Control Room Emer-gency Ventilation System (CREYS), Train B.
Electrical alignment can also be made to supply power from EDG 3B. EDG 3D provides emergency power to the Standby Gas Treatment System (SGTS). Train C. ~ This change does not affect the EDG requirements for Residual Heat Removal Service Water -(RHRSW), Fumps A3 and l
C3, because their function is only required as an alternative to the Unit 1 and 2 pumps for Emergency Equipment Cooling Water -(EECW) service.
This change establishes the specific requirements for Unit 3 EDGs for the condition where Unit 3 is in cold shutdown condition or defueled and specific CREVS or SGTS trains are required to support Unit 2.
Technical Specification Definitico E currently requires operability of the emergency power supply in order to consider a piece of equipment operable. Definition 1.C.2 contains an exception to this requirement (that applies only when the unit is not in cold l
shutdown or refuel) which allows the limiting condition for operation for EDGs to govern required actions. These definitions do not explicitly address 9101100P74 910109 ADOCKOSOOg9 PDR
.~
4 j
4 the situation where the unit being served (i.e., Unit 2) is not-in cold shutdown but Unit 3 is in cold shutdown or defueled. The limiting condition for operation for Unit 3 EDGs is not specified in this case and is determined by prudent judgment and administrative controls. The effect of this change is to inspose an explicit 30-day limit in the technical specifications for the diesel generators which supply power to SGTS Train C and CREVS Train B.
These are common subsystems which are required by technical specifications for unit operation and fuel handling. Therefore, this change results in a more limiting technical specification requirement than is currently specified.
The 30-day allowed out of-service time is justified based upon the decreased reliance on Unit 3 EDGs when Unit 3 is in cold shutdown or defueled.
Under these conditions the remaining equipment (Train B CREVS and Train C SGTS) and Unit 3 EDGs are capable of responding to an accident and/or loss of.offsite power. Technical Specification 3.9.D serves to enforce conservative actions in the event that the Unit 3 EDGs su) plying emergency power to SGTS Train C or CREYS Train B become inoperable, accause the existing Unit 2 Technical Specifications are based upon these trains being considered operable with no requirement for the operability of Unit 3 EDGs.
The existing Unit 2 technical i
specifications in Definition 1.C.2 allow continuous operation with no restriction whereas the proposed Section 3.9,0 limits the condition to 30 days.
Because it is more restrictive, this change does not adversely affect safety.
Surveillance requirements are specified for the Unit 3 EDGs, D.C. batteries, l
diesel generator logic, and under voltage detection relays, to assure continued operability. All of the testing currently required for EDGs i
associated with a fully operational unit will be implerrented with the exception of the following. Tests associated with the loss of offsite power /
LOCA response of the system to a Unit 3 accident are not required when Unit 3 is defueled. Surveillance requirements therefore exclude this condition. All of the testing requirements for diesel generator logic, D.C. batteries which support the required EDGs, and under voltage detection relays that would be required for a fully operational unit will be applicable.
Surveillance testing required for Unit 3 by T.S. 4.9.D.1.c, Logic Systems, verifies auto start of the Unit 3 DG from the Unit 2 accident signal.
The bases for Unit 2 Specification 3.9 are also modified to reflect changes resulting from the implementation of an engineering change. The revision to the bases reflects the fact that loss of a 250-V shut down board battery affects the control power for both 480-Y and 4160-Y shutdown boards.
The bases for Unit 2 Specification 4.9 are changed to delete reference to the use of Unit 1 loads to demonstrate the capability of the Units 1 and 2 EDGs to accept emergency loads. Unit 1 is presently shut down and defueled. Accord-ingly, TVA has tested the EDGs as part of its Unit 2 restart test program which included EDG res Accident (LOCA) ponse to the Unit 2 loss of offsite power (LOP / Loss of Coolant loads) application.
Yoltage and frequency responses were analyzed for acceptability based on transient and steady state voltage and frequencies not exceeding the electrical eouipment design.
NRC review of this Unit 2 Emergency Diest.1 Generator Loading Analysis has been documented in a safety evaluation dated December 21, 1989, i
,--r
,,,,,.,-,c-e....,,
f,1--,
- .r
---,-r..
1
.n
.r--
o 4
, 3.0 _ ENVIRONMENTAL CONSIDERATION The amendments involve a change to a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 70 and changes to the surveillance requirements.
The steff has i
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 si occupatIonalradiationexposure.gnificantincreaseinindividualorcumulative The Comission has previously issued a proposed finding that these arendments involve no significant hazards considera-tion and there has been no public coment on such finding. Accordingly, the amenaments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFP 51.22(b), no environmental impact-statement nor environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safet will not be endangered by cperation in the prososed manner,y of the public and(2)such activities will be conducted in compliance wit 1 the Comission's regulations, -
and (3) the issuance of the amendments will not be inimical to the comon defense and security nor to the health ard safety of the public.
Principal Cortributor:
D. H. Moran Dated: January 9,1991 l
..u,--....-,u._...---
. _.,.... _,,,. -, _.... ~ -
-,.----.... -