ML20244D811
| ML20244D811 | |
| Person / Time | |
|---|---|
| Site: | Seabrook, 05000000 |
| Issue date: | 04/24/1986 |
| From: | Rossi C Office of Nuclear Reactor Regulation |
| To: | Nerses V Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20235T530 | List:
|
| References | |
| FOIA-87-51 NUDOCS 8604290034 | |
| Download: ML20244D811 (4) | |
Text
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~Decsaf MR 2 4 1986 Go dR I r
C/l MEMORANDUM FOR:
V. Nerses, Project Manager PWR Project Directorate #5 Division of PWR Licensing-A FROM:
C. E. Rossi, Assistant Director for Technical Support 4
Division of PWR Licensing.A
SUBJECT:
SEABROOK - REQUESTS FOR ADDITIONAL INFORMATION RELATED TO THE INSTRUMENTATION AND CONTROL DESIGN Plant Name:
Seabrook Station, Unit 1 Docket No.:
50-443 Licensing Status:
OL Responsible Branch: PWR PD#5 Project Manager:
V. Nerses Review Branch:
EICSB/ DBL Review Status:
Incomplete The purpose of this memorandum is to forward requests for additional information related to the atmospheric dump valve control system design to be implemented at Seabrook.
Subsequent to staff approval of a manual control system associated with electro-hydraulic actuator operated atmospheric dump valves (ADVs), the applicant elected to modify the design by providing air operated ADVs with safety-related backup air (gas bottles) systems and controls. The applicant provided infonnation by letter dated February 14,19E6 to describe the latest design. However, upon review, the staff has concluded that the information is insufficient and, thus, the staff is not able to complete the review for this issue. The information identified in the enclosure is required for staff review before this item can be resolved. The enclosure should be forwarded to the applicant in an expeditious manner.
C. E. Rossi, Assistant Director for Technical Support Division of PWR Licensing-A
Enclosure:
As stated cc: See page 2
Contact:
R. Stevens (EICSB/ DBL)
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H. Thompson M. Srinivasan D. Cruthchfield G. Lainas V. Noonan F. Rosa S. Weis R. Stevens i
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ENCLOSURE
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l SEABROOK RE00EST FOR ADDITIONAL INFORMATION 1
The infonnation provided to date is insufficient to allow the staff to complete its review associated with the atmospheric dump valves (ADVs). Additional infonnation should be provided on the backup safety-related air supply system and the safety-related control system. The following should be provided as a minimum:
Information on the technical specification requirements to be implemented 1.
for the safety-related portion of the design (include a discussion on the provisions provided for surveillance testing of the ADVs and associated safety-related manual controls including the design features used for isolation from the nonsafety-related portion of the system),
Information on the failure modes and effects associated with the Train A j
2.
and Train B solenoid operated valves utilized to control operation of the ADVs. This should show as a minimum:
That the capability of the subject valves to perform the required safety functions (open/close as required for safe plant shutdown) cannot be degraded below an acceptable level as a result of all possible circumstances (i.e., overvoltage, undervoltage, etc.)
associated with the power supply to these valves. The main concern is with solenoid valves that are continuously energized during normal plant operation.
That the atmospheric dump valves fail to the closed pcsition on loss of power, That at least two (2) ADVs will be available for safe plant shutdown after assuming a single failure, and i
I That the nonsafety-related positioner will be isolated when required.
3.
A complete set of drawings (electrical schematics, logics, switch development tables, etc.) which show the latest design implementation associated with the ADVs.
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4.
Information on the design criteria associated with the mechanical aspects of the backup air supply system (bottles, tubing, valves, etc.).
Include details on the control room indications available for the operator to verify operability of the backup air supply system.
5.
Information detailing the actuator design associated with the ADVs.
6.
Information on the safety-related backup air system as related to the following concern. FSAR Section 7.3.2.3 implies that the safety-related backup air system may not have sufficient capacity to ensure that the -
necessary equipment is maintained in service to allow operation at hot standby for at least four hours and the additional time required for It is cooldown to conditions permitting (operation of the RHR system.nonsafety-relate stated that the plant air system loaded onto the diesel generator bus, or that local manual control will be established. Information is required to detail how this planned operation complies with the requirements of Branch Technical Position RSB 5-1, items A.1 and A. 3.
Details of the operator actions necessary for the operation of the ADVs for safe plant shutdown should be provided including identification of all deviations from the subject BTP requirements.
Justification information for each identified deviation should be provided.
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