ML19274C943
| ML19274C943 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 12/29/1978 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Davison D CLEVELAND ELECTRIC ILLUMINATING CO. |
| References | |
| NUDOCS 7901080034 | |
| Download: ML19274C943 (1) | |
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Ji8 Docket No. 50-440 Docket No. 50-441 The Cleveland Electric Illuminating Company ATTN:
Mr. Dalwyn R. Davids n Vice President - Engineering P. O. Box 5000 Cleveland, OH 44101 Gentlemen:
The enclosed IE Circular No. 78-19 is forwarded to you for information.
If there are any questions related to your understanding of the requested actions, please contact this office.
Sincerely, A$
James G. Kepp er Director
Enclosures:
1.
IE Circular No. 78-19 2.
List of IE Circulars Issued in 1978 cc /encls:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC U. Young Park, Power Siting Commission Mr. Daniel D. Wilt, Attorney 7901080034
U.S. UCCLEAR REGULATORY COMMISSION OFFICL OF INSPECTION AND ENFORCEMENT
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REG 105 III
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December 29, 1978 IE Circular No. 78-19 MANUAL OVERRIDE (BYPASS) 0F SAFETY SYSTEM ACTUATION SIGNALS Description of Circumstances:
A review of several recent events has raised questions aLaut safety syster circuit designs which incorporate manual override (bypass) features.
The two events described below directly relate to the practice of containment purging during normal plant operation by manually overriding containment isolation signals.
In these instances the automatic isolation function of the purge system cont inteat iscla-tien valves was unintentionally made inoperable, and this :-..ditien was neither continuously indicated in the control room nor knowr to the plant operators.
During a review of operating procedures on July 25, 1978, the Northeast Nuclear Energy Company discovered that since May 1, 1978, intermittent containment purge operations had been conducted at Millstone Unit No. 2 with the safety actuation isolation signals to both inlet and outlet redundant containment isolation valves (48 inch butterfly valves) in the purge inlet and outlet penetrations manually overridden and inoperable.
The isolation signals which are required to automatically close the purge valves for containment integrity were manually overridden to allow purging of containment with a high radiation signal present.
The manual override circuitry designed by the plant's architect / engineer defeated not only the high radiation signal but also all other isolation signals to these valves.
To manually override a safety actuation signal, the operator cycles the valve control switch to the closed position and then to the open position. This action energized a relay which blocked the safety signal and allowed manual operation independent of any safety actuation signal. This circuitry was designed to permit reopening these valves after an accident to allow manual operation of certain safety equipment.
On September 8, 1978, the Public Service Electric and Gas Company advised the staff that, as a matter of routine, Salem Unit No. I has been venting the containment through the containment ventilation syster valves to reduce pressure. In certain instances this venting has occurred with the containment high particulate radiation monitor isolation signal to the purge and pressure-vacuum relief valves overridden. Override of 7901040236
IE Circular No. 78-19 December 29, 197c
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the containment isolation signal was acccmplished by resetting the train A and B reset buttons. Under these circumstances, six valves in the containment vent and purge systems could be opened with a high particulate isolation signal present.
This override was performed af ter verifying that the actual containment particulate levels were acceptatie for venting. The licensee, after further investigation of this practice, determir.ed that the reset of the particulate alarm also bypasses the containment isolation signal to the purge valves and that the purge valves would not have automatically closed in the event of an emergency core cooling system (ECCS) safety injection signal.
These events and information gained from recent licensing actions have raised a generic concern relative to potential design deficiencies that could permit manually defeating a protection function.
Since all plants with construction permits must meet the requirements of IEEE 279, we recommend that you review the design of all safety actuation signal circuits which incorporate a manual override feature to ensure that overriding of one safety actuation signal does not also cause the bypass of any other safety actuation signal, that sufficient physical features are provided to facilitate adequate administrative controls, and that the use of each such manual override is annunciated at the system level for every system impacted.
Compliance with Federal Regulation 50.55a(h) requirements will be verified by NRC through the licensing review process and during regular onsite inspections for plants with construction permits.
NRC's requirements relative to this matter have been conveyed to all operating plant licensee's via a generic letter.
No written response to this Circular is required.
If you requirt additional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
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IE Circular No. 76-19 December 29, 1978 LISTING OF IE CIRCULARS ISSUED IN 1978 Circular Subj ec t Date Issued To No.
of Issue 78-01 Loss of Well Logging 4/5/76 All Holders cf Source Well Logcing Source Licenses 78-02 Proper Lubricating 011 4/20/78 All Holders of for Terry Turbines Reacter OLs er cps 76-03 Packaging Greater Thar 5/12/78 All Holders cf Type A Quantities of Reactor OLs, cps, Lov Specific Activity Fuel Cycle, Radioactive Material Priority I Materia:
for Transport and Waste Dispos 1 Licenses 76-O' Installation Error That 5/15/78 All Holders of Could Prevent Closing of Reactor OLs or Fire Doors cps 78-05 Inadvertent Safety Injection 5/.3/7F All Holders of During Cooldovr Reactor OLs er cps 76-06 Potential Common Mode 5/23/78 All Holders of Flooding of ECCS Equipment Reactor OLs er Rooms at BWR Facilities cps 78-07 Damaged components of a 5/31/78 All Holders of Bergen-Paterson Series Recctor OLs or 25000 Hydraulic Test cps Stand 78-0S Ervironmental Qualification 5/31/76 All Holders of of Safety Related Equipment Reactor OLs or at Nuclear Power Plants cps 78-09 Arcing of General Electric 6/5/78 All Holders of Company Size 2 Contactors cps Enclosure Page 1 of 2
IE Circular No. 7E-19 December 29, 1978
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LISTING OF IE CIRCULARS ISSUED IN 1978 Circular Subject Date of Issued to No.
Issue 78-10 Control of Sealed 6/14/78 All Medical Sources Used in Licensees ir Radiation Therapy Categories G and G1 78-11 Recirculation M-G 6/15/18 All Holders of Set Overspeed Stops BWR OLs or cps 78..
HPCI Turbine Control 6/30/78 All Holders cf Valve Lift Rod Bending BWR OLs or cps for plants with HFCI Terry Tur t in.;
78-13 Inoperability of Multiple 7/10/78 All Holders of Service Water Pumps Reactor OLs and cps except for plants located in: AL, AK, CA, FL, GA, LA, MS, SC 78-14 HICI Turbine Reve. sing 7/12/78 All Holders of BWR Charlar Hold Down Bolting Ols or cps for pla.ts with a HFCI Terry Turbine excepting Duane Arnold and Ment 1 cello 78-15 Checkvalves Fail to 7/20/78 All Holders of Close In Vertical Reactor OLs or cps Position 78-16 Limitorque Valve 7/26/78 All Holders of Actuators Reactor OLs or cps 18-17 Inadequate Guard Training /
10/13/78 All Holders cf Qualification and Falsified and applicants Training Records for Reactor OLs.
78-18 UL Fire Test 11/6/78 All Holders of Reactor OLs or cps Enclosure Page 2 of 2