ML19296D583
| ML19296D583 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/25/1980 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8003070008 | |
| Download: ML19296D583 (4) | |
Text
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UNITED STATES
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WASHINGTON, D. C. 2C555 fI v
February 25, 1980 Dockets Nos. 50-317 50-318 Mr. A. E. Lundvall, Jr.
Vice President - Supply Baltimore Gas & Electric Company P. O. Box 1475 Baltimore, Maryland 21203
Dear Mr. Lundvall:
By letters dated November 15 and December 14, 1979, you responded to our October 23, 1979 letter on Containment Purging at Calvert Cliffs Nuclear Power Plant, Units Nos. 1 and 2.
Your commitment to operate in conformance with the interim position enclosed with our October 23, 1979 letter is found acceptable on an interim basis. However, our long term concern regarding the design of all safety actuation signal circuits, as expressed in our November 29, 1978 letter, remains unresolved.
As a result of this generic review, we have established criteria regarding electrical override / bypass for use in the review of all operating reactors.
These criteria are presented in Enclosure 1.
You will note that some of these criteria overlap with our Lessons Learned requirements that resulted in your recent modifications to the containment isolation circuitry for both units.
We find that our review cannot continue without a more complete description of the Lessons Lerned Item 2.1.4 modification discussed in your January 4, 1980 letter.
You are requested to provide the additional information enumerated in Enclosure 2 within 30 days of the receipt of this letter.
Sincerely, h
V-Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosures:
1.
Containment Isolation Electrical Override / Bypass Design Criteria 2.
Request'for Additional Information cc w/ enclosures:
See rext page 8008070 ()0 f
Baltimore Gas & Electric Company cc:
James A. Biddison, Jr.
Mr, R. M. Douglass, Manager General Counsel Quality Assurance Department G and E Building Room 923 Gas & Electric Building Charles Center P. O. Box 1475 Baltimore, Maryland 21203 Baltimore, Maryland 21203 George F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D. C.
20036 Mr. R. C. L. Ol son Baltimore Gas and Electric Company Room 922 - G and E Building Post Of fice Box 1475 Baltimore, Maryland 21203 Mr. Leon B. Russell, Chief Engineer Calvert Cliffs Nucleat-Power Plant Baltinore Gas and Electric Company Lusby, Maryland 20657 Bechtel Power Corporation ATTN: fir. J. C. Judd Chief Nuclear Engineer 15740 Shady Grove Road Gaithersburg, Maryland 20760 Combustion Engineering, Inc.
ATTN: Mr. P. W. Kruse, Manager Engineering Services Post Office Box 500 Winosor, Connecticut 06095 Calvert County Library Prince Frederick, Maryland 20678
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s C0flTAINMEf1T ISOLATI0tl ELECTRICAL OVERRIDE / BYPASS DESIG?! CRITERIA 1.
The overriding *of one type of safety actuation signal (e.g., radiation) should not cause the blocking of any other type of safety actuation signal (e.g., pressure) to the isolation valves.
2.
Sufficient physical features (e.g., key lock switches) should be provided to facilitate adequate administrative controls.
3.
The system-level annunciation of the overridden status should be provided for every safety system impacted when an override is active.
4.
At least two diverse signals should be provided to initiate isolation of the containment ventilation system. Specifically, containment high radia-tion, safety injection actuation, and/or containrent high pressure should automatically initiate containment isolation.
5.
The instrumentation and control systems provided to initiate containment isolation should be designed and qualified as safety-grade equipment.
6.
The overriding or resetting *of the isolation actuation signal should not cause the automatic reopening of any isolation / purge valve.
The following definitions are given for clarity of use in this issue:
Override - the signal is still present, and it is blocked in order to perfonn a function contrary to the signal; D.aset - the signal has come and gone, and the circuit is being cleared to return to the nomal condition.
REQUEST FOR ADDITIONAL INFORMATION CONTAINMENT PURGE SYSTEM CLAVERT CLIFFS NUCLEAR POWER PLANT 00CKETS NOS. 50-317 AND 50-318 1.
Provide the details, including schematic drawings, of the modifications made to meet the Lessons Learned requirement 2.1.4.
2.
Describe how the modified containment isolation system prevents any valves from changing position automatically when the CIAS signal is reset.
3.
Discuss how your present safety system design conforms with each of the criteria.
4.
Describe any differences between the control of containment ventilation isolation valves and dampers and the valves and dampers of all other engineered safety features (ESF).
5.
If the system design of any ESF system contains an override, will the overriding of one type of safety actuation signal cause the blocking of any other type of safety actuation signal?
6.
Describe the features that are provided for bypassed and inoperable status indication.