ML19345H579
| ML19345H579 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 04/30/1981 |
| From: | Kountanis B EG&G, INC. |
| To: | Shemanski P Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19345H576 | List: |
| References | |
| CON-FIN-A-0231, CON-FIN-A-231 EGG-1183-4202, NUDOCS 8105210294 | |
| Download: ML19345H579 (15) | |
Text
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Q INTERIM REPORT A I.*:T2**.".'.T*.***
NRC TAC No.
10788 Report No.
EGG 1183-4202 Contract Program or Project
Title:
Electrical, Instrumentation, and Control System Support Subject of this Document:
Technical Evaluation of the Electrical, Instrumentation, and Control Design Aspects of the Override of Containment Purge Valve Isolation and Other Engineered Safety Feature Signals-for the Rancho Seco Nuclear Power Plant Type of Document:
Informal Report Author (s):
Prof;%.
B. Kountanis nary Date of Document:
April 1981 4
Responsible NRC Individual and NRC Office or Division:
Paul Shemanski, Division of Operating Reactors This document was prepared primarily for preliminary or internal use.
It has not received full review and approval. Since there,may be substantive changes, this document should not be considered final.
EGaG Energy Measurements Group San Ramon Operations San Ramon, CA 94583 Prepared for the U.S. Nuclear Regulatory Comission Washington. 0.C.
Under 00E Contract No.B&R 201904031 NRC FIN No. A-0231 INTERIM REPORT 7/6 G > /o p 7 y
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EGG 1183-4202 see operees.as April 1981 TECHNICAL EVALUATION OF THE ELECTRICAL, INSTRUMENTATION, AND CONTROL DESIGN ASPECTS OF THE l
OVERRIDE OF CONTAINMENT PURGE VALVE ISOLATION AND OTHER ENGINEERED SAFETY FEATURE SIGNALS FOR THE RANCHO SECO NUCLEAR POWER PLANT (DOCKET NO. 50-312) by B. Kountanis Approved for Publication I
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/$$ $ A s a 7 J. R. Radosevic Department Manager i
This document is UNCLASSIFIED i
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d ass ie :
Nicholas 4. Broderick Department Manager Work Performed for Lawrence Livermore National Laboratory under U.S. Department of Energy Contract No. DE-ACOS-76 NVO 1183.
ABSTRACT This report documents the technical evaluation of the electrical, instrtmentation, and control design aspects of the override of containment purge valve isolation and other engineered safety feature signals for Rancho Seco Nuclear Power Plant.
The review criteria are based on IEEE Std-279-1971 requirements for the safety signals to all purge and ventila-tion isolation valves.
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FOREWORD This report is supplied as part of the Selected Electrical,
Instrumentation, and Control Systems Issues (SEICSI) Program being con-ducted for the U.S.
Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Division of Operating Reactors, by Lawrence Livermore National Laboratory, Field Test Systems Division of tne Electronics Engineering Deparatment.
The U.S. Nuclear Regulatory Comission funded the work under an authorization entitled " Electrical. Instrumentation and Control System Support," B&R 2019 04 031, FIN A-0231.
The work was performed by EG&G, Inc., Energy Measurements Group, San Ramon Operations, for Lawrence Livermore National Laboratory uader U.S.
Department of Energy contract number DE-AC08-76NV01183.
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TABLE OF CONTENTS Page 1.
INTRODUCTION 1
2.
EVALUATION OF RANCHO SECO NUCLEAR POWER PLANT 3
2.1 Review Criteria.
3 2.2 Containment Ventilation Circuits Design Description 4
2.3 Containment Ventilation Isolation System Design Evaluation 5
2.4 Other Engineered Safety Feature System Circuits 6
3.
CONCLUSIONS.
7 REFERENCES.
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l TECHNICAL EVALUATION OF THE ELECTRICAL, INSTRUMENTATION, Af0 CONTROL DESIGN ASPECTS OF THE OVERRIDE OF CONTAINMENT PURGE VALVE ISOLATION AND OTHER ENGINEERED SAFETY FEATUR'2 SIGNALS FOR THE RANCHO SECO NUCLEAR POWER PLANT (Docket No. 50-312)
- 8. Kountanis EG&G, Inc., Energy Measurements Group, San Ramon Operations 1.
INTRODUCTION Several instances have been reported where autometic closure of the containment ventilation / purge valves would not have occurred because the safety actuation signals were either manually overridden or blocked during normal plant operations.
These events resulted from procedural inadequacies, design deficiencies, and. lack of proper management controls.
These events also brought 'nto question the mechanical operability of the containment isolation valvi s themselves.
These events were determined by the U. S. Nuclear Regulateiy Comission (NRC) to be an Abnormal Occurrence
(#78-5) and were, accordingly, reported to the U. S. Congress.
1 As a follow-up on this Abnormal Occurrence, the NRC staff is i
reviewing the electrical override aspects and the mechanical operability e
aspects of containment purging for all operating power reactors.
On November 29, 1978, the NRC issued a letter entitled " Containment Purging During Normal Plant Operation" [Ref.1] to all boiling water reactor (BWR) and pressurized water reactor (PWR) licensees.
In a letter [Ref. 23 dated January 4, 1979, the Sacramento Municipal Utility District (SMUD), the licensee for the Rancho Seco Nuclear Power Plant, replied to the NRC generic letter.
Additional information was requested by the NRC in a letter [Ref. 3] dated November 19, 1979. SMUD replied in a letter [Ref. 4]
dated February 22, 1980 and described design changes that they intend to make. Subsequent information was requested by an NRC letter [Ref. 5] dated August 14, 1980 and the reply was made in a letter dated September 30, 1980 [Ref. 6]. A conference call was made on February 19, 1981 [Ref. 7] to clarify and resolve several points with the licensee.
Additional refer-ences were used for this report and are listed in the reference section.
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2.
EVALUATION OF RANCHO SECO NUCLEAR POWER PLANT 2.1 REVIEW CRITERIA The Vimary intent of this evaluation is to determine that the following requirements are met for the safety signals to all ESF equipment.
(1)
Criterion no.1--In keeping with the requirements of GDC 55 and 56 [Ref. 8], the overriding
- of one type of safety actuation signal (e.g., radiation) should not cause the blocking of any other type of safety actu-ation signal (e.g., pressure) for those valves that have no function besides containment isolation.
(2)
Criterion no. 2--Sufficient physical features (e.g.,
keylock switches) are to be provided to facilitate adequate administrative controls.
(3)
Criterion no. 3--The system-level annunciation of the overriden status should be provided for ~every safety system impacted when any override is active (see R.G.
1.47).
9 Incidental to this review, the following additional NRC staff design criteria were used in the evaluation:
(1)
Criterion no. 4--Diverse signals should be provided to initiate isolation of the containment ventilation system.
Specifically, containment high radiation, 3
safety injection actuation, and containment high pressure (where containment high pressure is not a
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portion of safety injection actuation) should auto-natically initiate CVI.
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(2)
Criterion no. 5--The instrumentation and control systems provided to initiate the ESF should be de-signed and qualified as safety-grade equipment.
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(3)
Criterion no. 6--The overriding or resetting ** of the l
ESF actuation signal should not cause any ulve or l
damper to change position.
- The following definition is given for clarity of use in this evaluation:
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Override: The signal is still present, and it is blocked in l
order to perform a function contrary to the signal.
- The following definition is given for clarity of use in this evaluation:
l Reset:
The signal has come and gone, and circuit is being clered in order to return it to the normal condition.
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Ine control system does not nave any manual bypasses or over-rides.
Ine motor-operated valve circuit will not allow the valve to be opened manually as long as the SFAS signal is present.
The air-operated valves will also remain closed as long as tne SFAS signal is present.
Tnere is a non-safety grade radiation monitor in tne ventilation exnaust aucts which is used during purge.
Inis monitor will turn off tne reactor building exnaust fan on hign radiation if it is running or will prevent it from starting, but it will not initiate CVI.
A system-level manual CVI switch is not included in the design.
Manual isolation may be done by individually operating tne control switcnes for each valve.
2.3 CONTAINMENT VENTILATION ISOLATION SYSIEd OESIGN EVALUATION Ine CVI system does not nave any overrides wnicn stock any otner initiating signal since only one signal (SFAS) initiates CVI.
We conclude tnat criterion no. 1 is satisfied.
Since no interlocks or bypasses are included in the CVI system design, criteria nos. 2 and 3 are not applicable.
Ine CVI system is initiated oy tne SFAS signal whicn includes low reactor coolant pressure and nign reactor building pressure. Hign contain-ment radiation is not included as an automatic CVI initiating signal, nor is manual isolation at the system level.
We conclude tnat criterion no. 4 is not satisfied. However, the licensee nas committed to install a safety-grade radiation monitor [Ref. 7] in order to comply with criterion no. 4.
Based on the information received from the licensee, tne equip-ment used to initiate CVI is designed and qualified as safety-grade equipment.
We conclude that criterion no. S is satisfied.
Ine modifica-tion required to provide a containment nign radiation initiating signal will also be accomplished with safety-grade equipment.
Since tnere are no resets or overrides, criterion no. 6 is nnt applicable at tnis time.
Tne modifications for incorporating tne con-tainment nign radiation signal into tne CVI circuit must be review for compliance with tnis criterion.
Ine outboard CVI valves will presently open on loss of electrical power.
Tne licensee nas connitted to realace the existing solenoid valves and revise tne electrical Circuitry so LAat tne CV! Valve Will also Close on less of electric power [Ref.10].
3.
CONCLUSIONS The EI&C design aspects of containment purge valve isolation and other ESF signals for Rancho Seco Nuclear Power Plant were evaluated :1 sing those design criteria stated in Sectioin 2.1 of this report.
We conclude that, with t.ae modifications which the licensee has comitted to make, the containment ven*ilation isolation system design meets the NRC staff criteria.
Basec upon our audit of other ESF systems, we conclude tnat there is reasonable assurance that these systems also comply with the applicable criteria of Section 2.1.
However, we do recommend that the radiation monitor used to automatically isolate the control room be upgraded to be seismically and environmentally qualified as safety-related equipment.
Incidental to the review, it was noted that the CVI circuit does not have a system-level marnal isolation switch as specified by IEEE STD-279-1971 [Ref. 11].
We recomend that a manual system-level isolation switch be incorporated.
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REFERENCES 1.
16tC/00R letter (R. Reid) to Sacramento Municipal Utility District (J.
Mattimoe). " Containment Purging During Normal Plant Operation," dated November 29, 1978.
2.
SMUD letter (J. Mattimoe) to NRC/ DOR (R. Reid), no title, dated January 4, 1979.
3.
NRC/ DOR letter (R. Reid) to SMUD (J. Mattimoe), " Request for Addition-al Information on Containment Purge and Vent Systems," dated November 19, 1979.
4.
SMUD letter (J. Mattimoe) to NRC/ DOR (R. Reid), " Electrical Over-ride / Bypass Aspects of Containment Purge Systems," dated February 22, 1980.
5.
NRC/ DOR letter (T. Novak) to SMUD (J. Mattimoe), no titia, dated August 14, 1980.
6.
SMUD letter (J. Mattimoe) to NRC/ DOR (T. Novak), no title, dated September 30, 1980.
7.
Telephone conference call NRC (J. T. Beard and M. Padovan); Sacramento Municipal Utility District (R. Powers, L. Stevenson and R. Colombo);
EG&G, Inc., San Ramon (S. Kountanis), February 19, 1981.*
8.
10CFR50, Appendix A, General Design Criterion.
9.
U. S. NRC, TMI-2 Lessons Learned Task Force Status Report and Short g
Term Reconnendations, NURGE-0578, published July 1979.
8
- 10. SMUD letter (W. Walbridge) to NRC.(R. Engelken), no - title, dated November 19, 1980.
11.
Institute of Electrical and Electronic Engineers Standard 279-1971.
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DISTRIBUTION LIST LLNL/Livermore EG8G/SR0 Lawrence Livermore National Laboratory EG&G, Inc.
P. O. Box 808 P. 0. Box 204 Livermore, California 94550 San Ramon, California 94583 M.H.Dittmore,L-97(2 copies)
Author (2 copies)
C. E. Brown (4 copies)
B. G. Mayn K. W. Nishimura LLNL/ Nevada NRC Lawrence Livermore National Laboratory U. S. Nuclear Regulatory Commission P. O. Box 45 Bethesda, MD 20014 Mercury, Nevada 89023 W. E. Reeves, L-577 (2 copies)
J. T. Beard, MS-416 D. G. Ei seehut, MS-528 G.
Lainas, MS-416 l
P. C. Shemanski, MS-416 USD0E/NV00 USD0E/ TIC U. S. Department of Energy U. S. Department of Energy Nevada Operations Office Technical Information Center P. O. Box 14100 P. O. Box 62 Las Vegas, Nevada 89114 Gak Ridge, Tennessee 37830 J. A. Koch T. Abernathy (2 copies)
R. R. Loux R. B. Purcell l
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