ML17158A548
| ML17158A548 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/28/1994 |
| From: | Poslusny C Office of Nuclear Reactor Regulation |
| To: | Byram R PENNSYLVANIA POWER & LIGHT CO. |
| References | |
| TAC-M90341, TAC-M90342, NUDOCS 9411030331 | |
| Download: ML17158A548 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON> D.C. 20555-000I October 28, 1994 Hr. Robert G. Byram Senior Vice President-Nuclear Pennsylvania Power and Light Company 2 North Ninth Street Allentown, Pennsylvania 18101
SUBJECT:
RE(UEST FOR INFORMATION CONCERNING THE CLASS 1E/NON-CLASS 1E CIRCUIT INTERFACES IN THE SUSQUEHANNA STEAM ELECTRIC STATION (SSES)
UNITS 1
AND 2 DESIGNS (TAC NOS.
H90341 AND H90342)
Dear Hr. Byram:
As you are aware, the issue on circuit interfaces arose as a result of the 1986 incident at Susquehanna where an open circuit in a diesel generator field circuit produced an inductive surge which migrated through the plant computer and caused ground detection alarms on other diesel generators, This precipitated the staff questioning the adequacy of electrical isolation at the two units.
The staff concluded in its June 1991 safety evaluation (SE) that Pennsylvania Power
& Light Company (PP&L) actions, FSAR revisions, and justifications relative to concerns were adequate with the exception of the demonstration of the conformance of the GE Nuclear Steam Supply System scope of equipment to the requirements of IEEE 279-1971.
In that SE the staff indicated that it would wait for the results of an NRC generic review before it would take a position on the adequacy of the SSES designs.
As a followup to the August 30, 1994, meeting with Pennsylvania Power
& Light Company (PP&L) staff concerning the isolation of Class 1E circuits from non-Class 1E circuits, a conference call was held to discuss the status of the resolution of Generic Issue (GI) 161, '"Use of Non-Safety-Related Power Supplies in Safety-Related Circuits" relative to the isolation issue at SSES.
Although this GI was initiated by concerns about the Nine Hile Point 2 design, it was believed that the results would be applicable to SSES and would facilitate closure of the plant specific concerns.
We indicated during the conference call that the NRC Office of Research decided that GI-161 should not be addressed generically but should be resolved on a plant-specific basis as problems are identified.
Following that guidance, the staff has reconsidered its findings included in the 1991 SE addressing the isolation issue for Susquehanna and has revised its position on associated circuits included in the safety evaluation.
The SE implied that analyses or tests would not be acceptable for demonstrating the adequacy or acceptability of associated (non-Class 1E) circuits that are not isolated from safety circuits (Class 1E) by isolation devices..
However, the review of GI-161 determined that non-Class lE circuits that receive signals from Class IE equipment do not need to be electrically isolated by isolation devices if an analysis or test can demonstrate that the Class 1E circuit will not be degraded below an acceptable level when postulating credible failures ar U~
9411030331 941028 PDR ADOCK 05000387 P
occurring at the non-Class IE circuits.
Therefore, the staff believes that if PPKL can provide acceptable plant-specific analyses, or test results, then this will facilitate closure of this issue.
With this goal in mind, the staff hereby requests the following information.
l.
Identify all non-Class lE associated circuits at the plant that are not isolated from the Class 1E circuits by isolation devices.
2.
Provide analysis or test information that demonstrates that credible postulated failures in those non-Class 1E circuits would not degrade the associated Class 1E circuits below an acceptable level.
I expect to meet with your staff in the near future to discuss options for closure of this remaining aspect of this issue.
This requirement affects less than 10 respondents and, therefore, is not subject to Office of Management and Budget review under P.L.96-511.
Sincerely, Docket Nos."50-387/388 1
cc:
See next page DISTRIBUTION Docket File~
PUBLIC PDI-2 Reading, SVarga JZwolinski JStolz Chester
- Poslusny, Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Office,of Nuclear Reactor Regulation CPoslusny MO'Brien OGC ACRS(10)
- JWhite, RGN-I OFFICE PDI-2/P HICB D -2/D NAME CPoslusny:rb JWermiel JS DATE OFFICIAL RECORD COPY DOCUMENT NAME:
SU90341:RAI 94 (O i /94
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occurring at the non-Class IE circuits.
Therefore, the staff believes that if PP&L can provide acceptable plant-specific analyses, or test results, then this will'facilitate closure of this issue.
With this goal in mind, the staff hereby requests the following information.
1.
Identify all non-Class 1E associated circuits at the plant that are not isolated from the Class IE circuits by isolation devices.
2.
Provide analysis or test information that demonstrates that credible postulated failures in those non-Class IE circuits would not degrade the associated Class lE circuits below an acceptable level.
I expect to meet with your staff in the near future to discuss options for closure of this remaining aspect of this issue.
This requirement affects less than 10 respondents'nd, therefore, is not subject to Office of Management and Budg'et review unde} P.L.96-511.
Sincerely, Docket Nos.
50-387/388 cc:
See next page Chester
- Poslusny, Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Mr. Robert G.
Byram Pennsylvania Power
& Light Company Susquehanna Steam Electric Station, Units 1
& 2 CC:
Jay Silberg, Esq.
- Shaw, Pittman, Potts
& Trowbridge 2300 N Street N.W.
Washington, D.C.
20037 Bryan A. Snapp, Esq.
Assistant Corporate Counsel Pennsylvania Powei
& Light Company 2 North Ninth Street Allentown, Pennsyl varii a 18101 Mr. J.
M. Kenny Licensing Group Supervisor Pennsylvania Power
& Light Company 2 North Ninth Street Allentown, Pennsylvania 18101 Mr. Scott Barber Senior Resident Inspector U. S. Nuclear Regulatory Commission P.O.
Box 35 Berwick, Pennsylvania 18603-0035 Mr. William P. Dornsife, Director Bureau of Radiation Protection Pennsylvania Department of Environmental Resources P. 0.
Box 8469 Harrisburg, Pennsylvania 17105-8469 Mr. Jesse C. Tilton, III Allegheny Elec. Cooperative, Inc.
212 Locust Street P.O.
Box 1266 Harrisburg, Pennsylvania 17108-1266 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Pennsylvania 19406 Mr. Harold G. Stanley Vice President-Nuclear Operations Susquehanna Steam Electric Station Pennsylvania Power and Light Company Box 467 Berwick, Pennsylvania 18603 Mr. Herbert 0. Woodeshick Special Office of the President Pennsylvania Power and Light Company Rural Route 1,
Box 1797 Berwick, Pennsylvani.a 18603 George T. Jones Vice President-Nuclear Engineering Pennsylvania Power and Light Company 2 North Ninth Street Allentown, Pennsylvania 18101 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803
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