ML20032B132

Technical Evaluation of Electrical,Instrumentation & Control Design Aspects of Override of Containment Purge Valve Isolation & Other ESF Signals for Calvert Cliffs Nuclear Power Station Units 1 & 2

ML20032B132
Person / Time
Site:	Calvert Cliffs
Issue date:	04/30/1981
From:	Cooper J EG&G, INC.
To:
Shared Package
ML20032B129	List: ML20032B130 ML20032B132 ML20032B136
References
CON-FIN-A-0231, CON-FIN-A-231 EGG-1183-4181, EGG-1183-4181-R01, EGG-1183-4181-R1, NUDOCS 8111040581
Download: ML20032B132 (12)

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. MSag April 1931 TECHNICAL EVAI,UATION OF THE ELECTRICAL, INSTRUMENTATION, AND CONTROL DESIGN ASPECTS OFTHE OVERRIDE OF CONTA N!AENT PURGE VALVE 15CLAT10N AND OTHER ENGINEERED SAFETY FEATURE SIGNALS FOR THE CALVERT CLIFFS NUCLEAR POWER STATION, UNITS 1 AND 2

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by J. H. Cooper Approved for Publication

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'd. R. dadosevic Department Manager l

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Department Manager l

8111040581 811020 PDR ADOCK 05000317 P

pyg Work Performed for Lawrence Livermore National Laboratory under U.S. Department of Energy Contract No.DE.ACO8 75 NVO 1183.

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. ABSTRACT.

This report documents the technical evaluation of tne electrical, instrumentation, and control design aspects of the override of containment purge valve isolation and other engineered safety. feature signals for the Calvert Cliffs nuclear power station, Units 1 and 2.

The review criteria are based on IEEE Std-279-1971 requirements for the safety signals to all purge and ventilation isolation valves.

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s, FOREWORD This report is supplied as part of the Selected Electrical,

Instrumentation, and Control Systems Issues (SEICSI) Program being con-ducted for tne U.S.

Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Division of Operating Reactors, by Lawrence Livermore Laboratory, Field Test Systems Division of tne Electronics Engineering Department.

The U.S. Nuclear Regulatory Commission funded tne work under an authorization entitled " Elect:1 cal, Instrumentation and. Control System Support," B&R 20 19 C4 031, FIN A-0231.

The wo-k was performed by EG&G, Inc., Energy Measurements Group, San Ramon Operations, for Lawrence Livermore Laboratory under U. S. Depart-ment of Energy contract number OE-AC08-76NV01183.

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u TABLE OF CONTENTS Page 1.

INTRODUCTION.

1 2.

EVALUATION OF CALVERT CLIFFS NUCLEAR POWER STATION,

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UNITS 1 AND 2 3

2.1 Review Criteria 3

2.2 Containment ventilation Isolat. ion Circuits Design Description 4

2.3 Containment ventilation Isolation System Design Evaluation.

5 2.4 Other Engineered Safety Feature System Circuits 5

3.

CONCLUSIONS.

7 REFERENCES.

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TECHNICAL EVALUATION OF THE ELECTRICAL.

INSTRL' MENTATION, AND CONTROL DESIGN ASPECTS OF THE OVERRIDE OF CONTAINMENT PURGE VALVE ISOLATION AND OTHER ENGINEERED SAFETY FEATURE SIGNALS FOR THE-CALVERT CLIFFS NUCLEAR POWER STATION, UNITS 1 AND 2

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(Docket No. 50-317 and 50-318)

J. H. Cooper EG&G, Inc., Energy Measurements Group, San Ramon Operations.

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INTRODUCTION

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instances nave been reported wnere automatic closure of Several

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the containment ventilation / purge valves woulo not nave occurred because

_t e. sa ety ac uation signals were either manually overridden or blocked h

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during normal pl ant' operations.

These events resulted from procedural inadequacies, design deficiencies, and lack of proper management controls.

These events also brought into question tne mechanical operability of the containment isolation valves themselves.

Tnese events were determined by the U.S. Nuclear Regulatory Comission (NRC) to be an Abnormal Occurrence

(#78-5) and were, accordingly, reported to the U.S. Congress.

As a follow-up on this Abnormal Occurrence, the NRC staff is

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reviewing tne electrical override aspects and-tne mechanical operability aspects nf containment purging for all ' operating power reactors.

On November 28, 1978, the NRC issued a letter entitled " Containment Purging During Normal Plant Operacion" [Ref.1] to all boiling water reactor (SWR) and pressurized water reactor (PWR) licensees.

In a letter dated January 12, 1979 [Ref. 2], the Baltimore Gas and Electric Company (BGEC), the licensee for the Calvert Cliffs nuclear power station, Units 1 and - 2 re-plied to the NRC generic letter.

In a conference call [Ref. 3] and in" references 4, 5, and 6 the licensee. described the purge valve isolation.

system design changes made to the Calvert Cliffs nuclear power station, Units 1 and 2, as discussed later in this report.

This document addresses only the electrical, instrumentation, and control (EI&C) design aspects of tie containment ventilation isolation (CVI) and other engineered safety features (ESFs).

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EVALUATION OF CALVERT CLIFFS NUCLEAR POWER STATION, UNITS 1 AND 2 2.1 REVIEW CRITERIA The primary 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 tne roquirements of GDC 55 and 56, the overriding

• of one type of safety

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actuation signal (e.g., radiation) ' should not cause the blocking of any otner type of safety actuation signal (e.g., pressure) for tnose valves tnat nave 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 overridden status should be provided'for every safety system impacted when any override is active (see R.G.

1.47).

Incidental to this review, tne 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 nign radiation, safety injection actuation, and containment nign pressure (wnere containment nign pressure is not a portion of safety injection actuation) snould auto-matically initiate CVI.

(2)

C riterion no. 5--The instrumentation and control systems provided to initiate the ESF should be designed and qualified as safety-grade equipment.

• Ine following definition is given for clarity of use in this evaluation:

Override:

The signal is still present, ' and it is blocked in order to perform a function costre.ry to the signal..

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V by the licensee was reviewed for compliance with the criteria.

This in-formation covered the containment purge isolation system, containment 4-oxygen analyzer' isolation, and the matr. steam isolation. fan system.

Re-suits of this audit were applied to the containment purge valve review.

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1 The licensee for Calvert Cliffs stated in the letter of April 7, 5

1980 [Ref. 4], that' the safety actuation signals (SAS) have blocks -(over-P rides) that are keylock-operated and 'P.at they provide for orderly accom-plishment of normal-plant functions, such as shutdown.. Blocks.(overri. des) j; to the SAS can be applied only if limiting conditions for operatiort are met.

The blocks are a6.nunciated at the system _ level and are automatically removed. Blocking of any one signal does not. block any other-signal.

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T's April 7,1980. l'etter [Ref. 43 al'so states' th'at the instru-mentation and control systems that initiate the ESF are. designed and qualified as. safety-grade equipment. The licensee stated.that. resetting of-the isolation signal of the modified system with reset permissive will not cause the automatic, motion of any ESF valve.

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Y The valve control logic # nas been revised to incorporate a reset permissive, so ~that if a trip occurs and in'e:systsm is subsequently reset, the system.Will remain isolated "until eacn valve is indiWdually reset.

The valves are also controlled manually at the. train level.

Indicator

% ea'gnts are provided for each control, train, as ara indicator lignts for

'li cn v, 'Ive position indic'ation.

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w.c idhen a monitored p'i ant" conditdoh. cal'Is for isolation, a trip t%[ \\ 'i A N

occurs, E3FAS train A and/or B anditne trip contacts open causing drop-x p' out of f.ned:ontrol relays A Trip capta' cts'ealso open in the valve control

'caasing4%.energiting of th(pnta$r. ment tisolation valves, wnien Jolentigvelyes.. The air control valves clor,y, force.rel.oyino ser from;tre spring m.

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) CONTAINMENT VENTILATION ISOLATION SYSTEM DESIGN EVAL.UATION In response to triis issue,'[r.no l'i[censee for Calvert Cliffs nas 3&

coun(,tted to minimi;ing tne numoer and duration' of purges, most of wnicn

' are, performed on an interim basisy en the plant is at or below tne not 2

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Tne conta'fament ventil:41!ich isolatior' system (CIS) nas no over-

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frvas 'and no signai's, are blocMed as stated,',1 the licensee's letter of May 127i't?80 [Ref. 6]. We Moncluce tnat NRC crit rion-no. 1 is not applicable, i 'Gimilarly, NRC criteria nos. 2 and 3 are no,tl applicable.

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f CIS is initiated by nign reactor"bisilding pressure only and lacks tM civersity.

In tne letter dated May 27,1980 [Ref. 6], tne Itcensee agreed to add tne s?.fety tion actuation signil (SIAS) to CIS and containment raatation signal Tne completioni date for diverse initiation is given in a lette, jacbd October 19,1979 '[Ref. 5] as January 1,1980 for Unit 2 and at tne Soring,1980 outage for Unit 1.

Witn tne addition of tne SfAS and CRS, NRC criterion no. 4 will be met.

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In the letter dated May 27, 1980, paragrapn 1 (1) and (2) [Ref.

$], tne licensee states tuk:.tM instrumentation and control systems pro-vided to initiate engineereo hfeguards and CRS are designed and qualified l, %

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Paragrapn 2 of Reference 5,'and a letter dated g goril 7,1980 [Ref. 4], state that witn tne modified, system, resetting of i

1 Y tne isolation signal will not cause automatic motion of any ESF valve.

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n O, RevQw of themodification to the circu{try verifies tnis feature.

x We conclude that NRC criteria nos,(i and 6 are satisfied.

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OTHER ENGINEERED. SAFETY FEATURE (ESF) l?YS L

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In the coursetof thisVeview, otner ESF systems were audited for compliance witn tn'e crite'ria previously listed.

The information provided

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by the licenree_ was r3 viewed for compliance witn the c.*iteria.

This in-formation covered tne containment purge isolation system, containment oxygen analyzer isolation, and the main steam isolation. fan *. system.

Re-suits of this audi. were applied to the containment purge valve review.

The licensee for Calvert Cliffs stated in the letter of April 7, 1980 [Ref. 43, that the safety actuation signals (SAS) have blocks (over-

.. rides) that are keylock-operated and that they provide for orderly accom-plishment of nor.nal plant functions, such as snutdown.. Blocks.(overri. des) to the SAS can be applied only if limitira conditions for operatiort are met.

The Diocks are annunciated at the system level and are automatically removed. Blocking of any one signal does not block any other" signal.

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CONCLUSIONS Tha El&C design aspects of containment purge valve isolation and otner ESF signals for Calvert Cliffs Nuclear Powea Station were evaluated us' ig those design criteria stated in Section 2.1 of tnis report.

We conclude tnat wnen the modifications proposed by the licensee are completed, the design of the CVI system wiil meet the NkC staff criteria.

We also conclude that tne otner ESF circuit designs audited meet tne NRC staff criteria.

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REFERENCES 1.

NRC/00R letter (R. Reid) to BGEC, " Containment Purging During Normal Plant Operation," dated November 29, 1978.

2.

BGEC letter (A.E. Lundvall) to NRC (R. Reid), " Containment Purging During Normal Plant Operations, Calvert Cliffs Nuclear Powe: Station, Units 1 and 2," dated January 12, 1979.

3.

Telephone conference call with NRC, EG&G, and Baltimors Gas and Electric Company, February 11, 1980.

4.

BGEC letter (A.E. Lundvall) to NRC (R. Reid), "Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Docket nos. 50-317 and 50-318, Containment Purge and Isolation," dated April 7, 1980.

5.

BGEC letter (A.E. Lundvall) to NRC (0.G. Eisennut), "Calvert Cliff.

Nuclear Power. Plant, Units-1 and 2, Occket nos. 50-317. and 50-318, Follow-up Actions Resulting from TMI-2 Incident. (Lessons Learned),"

dated October 19, 1979.

6, SGEC letter (R.C.L. Olson) to EG&G (J.H. Cooper) "Calvert Cliffs Nuclear Fower Plant Containment Purge Systeta," dated May 27, 1980.

7.

U.S. Nuclear Regulatory Comission, "TMI-2 Lessons Learned Task Force Status Report and Short-Term Recomendations," NUREG-0578.

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DISTRIBUTION LIST LLNL/Livermore EGAG/SRO t-

. Lawrence Livermore National Laboratory EG&G, Inc.

r P. O. Box'808 P. 0. Box 204 Livennore, California 94550 San Ramon, California 94583 Author (2 copies)

M. H. Dittmore, L-97 (2 copies)

C. E. Brown (4 copies)

B. G. Mayn M. W. Ni snimura

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74'** LLNL/ Nevada NRC

. Lawrence Livermore National Laboratory U. S. Nuclear Regula' tory Commission

-P. O. Box 45 Bethesda, MD 20014 Mercury, Nevada 89023 W. E. Reeves, L-577 (2 copies)

J. T. Beard, MS-416 U. G. Ei sennut MS-528 G.

Lainas, MS-416 P. C. Shemanski, MS-416

'JS00E/NV00 US00E/ TIC L'. 5. Department of Energy V. S. Department of Energy Nevada Operations Office Tecnnical Information Center P. O. Box 14100 P. O. Box 62 Las Vegas, Nevada 89114 Gak Ridge, Tennessee 37330 J. A. Koch-T. Abernatny (2 copies),

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NRC Position Concerning Testing of Containment Purge / Vent Valves w

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As a result of numerous reports on the unsatisfactory performance of.

resilient seats in butterfly-type isolation valves due to seal deterioration, a

l periodic leakage integrity tests of the 48-inch butterfly isolation valves r

in the purge system are necessary. Therefore, the licensee should also propose Technical Specification for testing the. valves,in accordance with i

r the following testing frequency:

"The leakage integrity tests of the isolation valves in the containment purge / vent lines shall be conducted at least once every three manths".

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The purpose of the leakage integrity tests of the isolation valves in the containment purge lines is to identify execssive degradation of the resilient seats for these valves. Therefore, they need not be conducted with the precision required for the Type C isolation valve tests in 10 CFR Part 50, Appendix J.

These tests would be performed in addition to the quantitative Type C tests required by Appendix J, and would not relieve the licensee of the responsibility to conform to the requirements of Appendix J.

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Encloture 6 Safety Evaluation Report Minimum Containment Pressure Setpoint (Item II.E.4.2(5) of NUREG-0737)' :.>

Calvert Cliffs Nuclear Power Plant, Unit: l'and 2.

Docket Nos: 50-317, 318 1.0 Introduction As a consequence of the accident at TMI-2, implementation of a nuober,of new.

requirements has been recommended for operating reactors. These new require-cents ar:a described in NUREG-0660, "NRC Action Plan Developed as a Result of the THI-2 Accident " May 1980, and NUREG-0737, " Clarification of TMI Action '

Plan Requirements," November 1980. The NRC, staff has also requested lican-sees to submit information sufficient to permit an independent evaluation of their response to these new requirements. This report prcvides an evaluation of. the 'res'ponse. to Action P1'an Item II.E.4.2, position 5, by t].e designated ifcensee.

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2.0 Evaluation Our consultant, the EGiG Energy Measurements Group (a subcontractor to Lawrence Livere:re Nati:nal Lab:ratory, which has the TMI Actt:n Flan contract) has reviewed the licensee's submittals and prepared the attached technical evaluation re; rt of the licensee's c:ntainment pressure setpoint used to isolate nonessential centainmenc penetrations.

We have reviewed this evaluation and ccncur in its basis and findings.

3.0 Cenclusions The infor:ation submitted by.the-lipensee frovi.ded sufficient detatis of the licensee's[contairoent isolatfon. pressure for the staff to conclude th'at' the requirements of Item II.E.4.2(5) of NUREG-0737, with the additional guidelines developed by che staff, have been met.

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