RBG-41486, Discusses LAR 94-04,extending Action Times of Leakage Control Sys
| ML20083R845 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/19/1995 |
| From: | James Fisicaro ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RBF1-95-0117, RBF1-95-117, RBG-41486, TAC-M88832, NUDOCS 9505300173 | |
| Download: ML20083R845 (4) | |
Text
_--
I Entergy Operations. Inc.
R,ver Bend Staton
.M 5485 U.S. H.ghway 61 i Fr nc sv e, LA 70775 Tel 504 336 0225 F a4 504 635 5008 i
James J. Fisicaro f[
safety 1
May 19,1995 I
U. S. Nuclear Regulatory Commission Document Control Desk Mail Stop P1-37 Washington, DC 20555 l
l
Subject:
River Bend Station - Unit I l
Docket No. 50-458 License No. NPF-47 l
License Amendment Request (LAR) 94-04, Leakage Control Systems l
(TAC M-88832) 1 i
File Nos.:
G9.5, G9.42
Reference:
RBG-40144, dated February 22,1994 RBF1-95-0117 RBG-41486 l
Gentlemen:
l On February 22,1994, Entergy Operations Inc. (EOI) submitted an application for l
amendment to the River Bend Station (RBS) Technical Specifications (TS), License Amendment Request (LAR) 94-04 (Reference 1). Included were proposed changes which would extend the ACTION times of the leakage control systems. The submittal is based on specification 3.6.1.8 and 3.6.1.9 of NUREG-1434, " Standard Technical Specification General Electric Plants, BWR/6."
On April 20,1995, the NRC Staff and RBS personnel discussed a concern over LAR 94-
- 04. The concern deals with the change to the ACTION statement in the event both divisions of the penetration valve leakage control system (LSV) becom'e inoperable due to unavailability of the LSV compressors and/or accumulator tanks. Under these conditions there would be no back-up air supply to the safety relief valves (SRVs) individual Steam Safety and Relief Valve System (SVV) air accumulators.
I 9505300173 950519 PDR ADOCK 05000458
/
g p
{
l
____=
License Arnendment Request 94-04 RBP1-95-ol l7 RHG-41486 May 19,1995 Page 2 of 3 The NRC initially suggested the use of bottled air or nitrogen as back-up when both LSV accumulators and/or compressors are inoperable. RBS agrees the use of bottles is an acceptable alternate supply but the use of this alternate may result in additional operator actions during an event.
During the ensuing investigation into the feasibility of using bottles as a backup, RBS identified the current installation of a diesel-driven air compressor capable of supplying the plant instrument air (IAS) and service air (SAS) systems at pressures about 135 psig. The IAS supply is hard-piped to both the SVV air supply air dryers' inlet and the divisional LSV piping. The piping downstream of the LSV accumulator tank provides back-up to the SVV divisional air supply header. The connections from IAS to LSV contain isolations which prevent a failure in the IAS piping system from affecting the safety-related LSV system.
A modification curn:ntly being installed makes a number of pennanent changes and improvements in the plant IAS/SAS systems. These changes provide for isolating SAS loads in order to mamtain IAS loads with any one of the nonnal IAS or SAS compressors (three IAS and three SAS electric air compressors) or the diesel air compressor supplying the loads. The diesel compressor's ability to operate is currently confinned by weekly testing.
The design of the SVV air supply system, discussed in USAR Section 5.2, includes an air accumulator for each SRV. The seven Automatic Depn:ssurization System (ADS) SRVs' SVV accumulators are capable of providing sufficient air pressure for a minimum of three lifts of each valve. The nine non-ADS SRVs' SVV accumulators are capable of providing sufficient air pressure for a minimum of one lift of each valve under design conditions. The ADS design basis (reactor isolation and failure of high pressure injection) requires a single lift of six of the seven ADS SRVs. The concern is for the long-term post accident / event availability (beyond DBA) of SRVs for reactor vessel pressure control. As discussed above, the LSV provides long-tenn backup-air supply to the SRVs through the LSV air accumulators which are maintained at pressures at or above 101 psig.
To resolve the NRC's concern, RBS proposes to place additional guidance in the current Technical Requirements Manual (see attachment). This guidance directs the operator to verify the availability of an alternate air supply upon the loss of both LSV air compressors /
accumulators. With this verification, the operator is directed to maintain the availability of the alternate supply, thereby assuring long-tenn SRV function. The time period of four hours provides sufficient time for the operator to confinn availability of the alternate backup air supply to SRVs. The proposed time to supply an alternate is based on the unlikelihood of multiple failures resulting in loss of the backup supply (LSV) and an event requiring this feature. The addition to the LSV BASES provides guidance regarding an acceptable alternate.
License Amendment Request 94-04 RBEl-95-0117 RBO-41486 May 19,1995 Page 3 of 3 Please note, TS 4.5.1.f requires the ADS header pressure to be above 131 psig (which also supplies all SRVs). If air pressure is less than 131 psig, the required ACTION is to reach IIOT SIIUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and less than 100 psig in the reactor vessel within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. As a result, the OPERABILITY of the ADS system must be confirmed or appropriate ACTIONS taken.
These clarifications have been discussed with RBS's NRR Project Manager. Based on these discussions, RBS recommends including these clarifications in the requested amendment. The proposed clarifications do not impact the scope of the original submittal and maintain the availability of the SRVs; therefore, they are bounded by the No Significant Hazards Considerations previously submitted in RBO-40144. If you have any questions or comments, please contact Mr. Otto P. Bulich of my staff at (504) 336-6251.
Very truly yours, de A %
JJF/jr attachment cc: Mr. David L. Wigginton U. S. Nuclear Regulatory Commission M/S OWFN 13-11-2 Washington, DC 20555 NRC Resident Inspector P. O. Box 1051 St. Francisville, LA 70775 U. S. Nuclear Regulatory Commission j
Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011
License Asnendment Request 94-04 4
RBIU95-0117 RBG-41486
' Attachment Technical Requirements Manual additions The following will be added to the Technical Requirements Manual upon receipt of approval of the requested amendment. Specification 3.6.1.10 PENETRATION VALVE LEAXAGE CONTROL SYSTEM Insert:
ACTION With both PVLCS air compressor / accumulators inoperable, within four hours verify availability of an alternate back-up air supply to the SVV air supply headers or initiate actions to provide an alternate within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
SURVEILLANCE With this ACTION entered confirm the continued availability of the alternate. supply once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The following is to be added to the Technical Specifications BASES of LSV,3.6.1.10 for the current specifications.
An alternate air supply to the SVV accumulators is considered to be air pressure at or above 101 psi delivered by a diesel-driven air compressor or other supply source not dependent on off-site power.
Note: the above information will also be included in the Improved Technical Specifications.
~
1