ML17164A567
| ML17164A567 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 01/31/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17164A566 | List: |
| References | |
| NUDOCS 9502080355 | |
| Download: ML17164A567 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0.141TO FACILIT OPERATING LICENSE NO. NPF-14 AMENDMENT NO. 111TO FACILITY OPERATING LICENSE NO. NPF-22 PENNSYLVANIA POWER 5 LIGHT COMPANY LLEGHENY ELECTRIC COO ERATIVE INC.
SUS UEHANNA STEAM ELECTRIC STATION UNITS 1
AND 2 DOCKET NOS.
50-387 AND 388
- 1. 0 INTRODUCTION By letter dated October 25, 1994, the Pennsylvania Power and Light Company (the licensee) submitted a request for changes to the Susquehanna Steam Electric Station, Units 1 and 2, Technical Specifications (TS).
The requested changes would add to the SSES Unit 1 and 2 Technical Specifications isolation signals to Table 3.6.3-1 for the containment isolation valves on the sample lines for the containment radiation monitoring (CRM) and wetwell sample lines.
This change is based on the licensee's design change for installation of a new CRM and wetwell sample system.
2.0 BACKGROUND
As discussed in the Final Safety Evaluation Report for the SSES units, the Containment Radiation Monitoring system consists of two 100 percent redundant systems that are part of the Reactor Coolant Pressure Boundary (RCPB)
Leak Detection System.
The CRM (high range) is designed to monitor containment radiation during and after a loss-of-coolant-accident (LOCA) or other
- accident, provides an alarm of high radiation levels annunciated in the control
- room, and provides an indication and historical record of radiation during and after an accident.
The CRM is not a safety-related system;
- however, the isolation of the CRM sample lines is part of the containment isolation system which is safety-reiated.
Each CRM system consists of a single cabinet structure containing a particulate monitor, iodine monitor, and noble gas monitor.
The CRM share the containment drywell and wetwell piping with the Hydrogen/Oxygen analyzers and Post Accident Sample System (PASS).
3.0 EVALUATION Because of numerous operational and maintenance problems with the CRM system, PP8L proposes to install a new system and change the sample lines.
These changes will provide a more reliable and representative containment air sample with acceptable plate-out limits.
9502080355 950132 PDR ADOCK 05000387 P
The proposed modification is to add both a new CRM and wetwell sample system with separate containment sample lines which will replace the existing CRHs.
The existing CRMs will be removed from the Containment Atmospheric Control (CAC) sample lines.
The new CRM and wetwell sample lines will have inboard isolation valves supplied with Division I control power and the outboard valves are supplied with Division II control power.
These redundant power circuits are to be physically and electrically separated.
In addition, the control power to the CRH is fed through isolation devises such that failure of the CRH under accident conditions is isolated from the Class If systems.
The isolation valves can be operated either manually or closed automatically.
The valves are closed automatically by their redundant associated LOCA signal.
The setpoint for the LOCA signal is either Reactor Vessel Water -Low, Low Level (-38.0 inches) or Drywell Pressure-High(1.72 psig).
This LOCA signal is the same signal for the existing CAC isolation valves.
The fail-safe position of the isolation valves is in the closed position.
Inadvertent operation which closes an isolation valve to the CRH would be sensed and a low flow or high pump discharge pressure would cause the CRH sample pump to shut down.
For the Wetwell Sample Rack, inadvertent closure of isolation valves while a grab sample was being taken would be indicated locally as low flow on a flow indicator at the grab sample rack and requires operator action to turn off the sample pump.
PP8L stated that the isolation valves and all the power and control components have been qualified and indicated that it has analyzed the isolation system and has not identified any single failure which could prevent the isolation function.
The proposed changes to the technical specifications (TS) add isolation signals to Table 3.6.3-1 for the containment isolation valves on the sample lines for the CRH and wetwell sample lines and removes Note f (Solenoid valves not capable of being opened due to the absence of permanently installed electrical power.)
from the table.
This change governs the operability of the primary containment isolation valves for the sample lines to the new CRHs and wetwell sample rack by establishing the maximum isolation time.
Such a
requirement ensures that the containment atmosphere is isolated from outside environment following a release of radioactive material to the containment atmosphere or following the pressurization of the containment.
Since the licensee has indicated that the new isolation valves are solenoid valves which immediately close upon receipt of an accident signal, the staff finds that their design is consistent with GDC 54-57 of 10 CFR Part 50, Appendix A.
PPKL has evaluated this modification to assure that the proposed changes do not:
(I) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
The staff agrees with the licensee's evaluation.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendments.
The State official had no comments.
5.0 ENVIRONMENTAL CONSIDER ON 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.
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 (59 FR 63126).
Accordingly, the amendments meet eligibility criteria for categorical exclusion set forth 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 connection with the issuance of the amendments.
6.0 CONCLUSION
PPKL has proposed a design for the CRM and wetwell sample line isolation which meets the requirements of the safety-related containment isolation system and is equal to or is an improvement in the design of the systems which are currently installed at the plant.
The staff has evaluated the PP8L proposed change to the CRN and wetwell sample system and the TS and finds these changes acceptable.
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.
Principal Contributors:
F. Paulitz C. Poslusny Date:
January 31, 1995