ML19329E370

Forwards IE Circular 77-13, Reactor Safety Signals Negated During Testing. No Action Required

ML19329E370
Person / Time
Site:	Midland
Issue date:	09/23/1977
From:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
References
NUDOCS 8006120682
Download: ML19329E370 (1)

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CENTRAL FILES.

r-~231977 Dochot No.I"o-1 D Dechet No.50-33D Consumers Power Cocpany i

Ar.1: lir. Stephen 11. Houcli Vice President j

1945 Want Parnall noad Jachaon, MI 49201 l

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j The encioned Circular Ho. 77-13, ia foruceded to you for information. If charc are any questions reisted to your understanding,of the ou3gested actions, please contact this offico.

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l Sincerely, t

ij James G. Roppler j

Director t

Enclosure:

IE circular No. 77-13 i

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' September 23, 1977 IE Circular No. 77-13 REACTOR SAFETY SIGNALS NEGATED DURING TESTING On July 12, 1977, the Commonucalth Edison Company reported that uhile conducting a curveillance test at Zion Unit 2, test cignals ucre simul-l taneously injected into several censors which affected both protection l

and control systems.

Injection of thecc test signals resulted in:

(1) the loco of instrument indications for the affceted protection and control cystems, (2) the locc of automatic control capability for the affected control systems, and (3) tha locc of automatic protection capability for the affected protection cystenc.

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At the time of the ovent, the unit var in a hot shutdotn condition and preparations for start-up uere undcruay. Station management decided to perform a surveillance test of the reactor protection logic circuitry.

1 A combination of test procedure inadequacies and the failure to follcu prescribcd administrative controla related to instrumentation tecting icd to the incertion of test signals which replaced the actual signals from three preccuriter water level censorc, three water level sensors in cach of the four etcan generatorc, four prescurizer preccure sensors l

and three flow concorc in cach of the primary coolant loops. The test signals had been inserted for approximately 40 minutes uhen, due to unexpected indicationc of the main coolant pump seal flow rate and other anomalouc indicatienc, the operator requested that the test signala be removed. When the test cignals ucre removed, it was observed that the proccuri cd water level had dropped below the range of indication.

The drop in pressuricer water icvel resulted from the proccurizer unter l

level test signal being slightly higher than the automatic precourizer level control cet point.

In response to this condition the changing pump flou vac automatically reduced to the minimum pump flow rato, which l

vac maintained until the test nigualc ucre removed. During this forty i

minute period the letdown flow remained constant. Consequently, the rate at which coolant unu being removed from the primary coolant cystem was approximately 75 cpm creater than the rate at uhich coolant. unc being returned to the system. Approximately 5300 g.tllonc of water una required to bring the preocurizer water level back to its original level of twenty-two percent.

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- IE Circular No. 77-13 September 23, 1977 As mentioned above, ' operator action, in response to other availabic instrumention indications terminated the event.

Subsequent investiga-tion by the licensen revealed that no damage to plant equipment was

' sustained durinC or after the event.

This incident represents an exampic of an event which resulted from a series of errors involving:lan management control and improper attention of plant-personnel to established procedures.

All holders of operating licences should be aware of the potential for adverse operational events which can' occur during performance of parti-cular surveillance tests. For exacple, if an excessive number of safety

- sensors are disabled simultaneously as was the case in this event, automatic action may not occur as intended. Care cust be taken to assure that test signals.do not negate automatic initiation of protection systems.

It is recommended that the follouing considerations be incor-porated in your reviews of this matter.

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Facility procedures should specifically identify the limitations and restrictions which are required for each mode of operation during which testing or surveillance activities may be conducted j

such that required safety protection systems will remain operable in accordance with the facility Technical Specifications.

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In order to provide additional assurance that required safety related capabilitics of plant systems are not defeated during testing or surveillance activities, training programs for opera-tions and craft persennel should include sufficient information to. assure an indepth understanding of system functions, system interactions, and Technical Specification requirements.

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Management controls should be strengtheced ac necessary to assure adherence to administrative procedures involving revieus,' approvals, and concunication betueen, plant supervi-sion, operaturn and craft personnel performing testing and surveillance activitics.

Such controls should consider the

man-machine" interfaces, and should assure that. the human component of this pair is not overburdent !.

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g IE Circular No. 77-13 September 23, 1977 No written renponse to thic Circular is required.

If you require additional information regarding this natter, contact the Director of the appropriate MitC Regional Of fice.

IE inspnctors will review this raatter with licenaces during future inspections.

Enclosure:

List of IE Circulars:

Issued in 1977 P

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LISTING OF IE CIRCULARS ISSUED IN 1977 CIRCULAR SUDJECT FIRST DATE OF ISSUED TO HO.

ISSUE 77-01 Malfunctions of 1-4-77 All holdere of Limitorque Valve Operating Licer.rt Operators (OL) or Constru:-

tion permit (C?}

77-02

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Potential Heavy 2-15-77 All affected Spring Flooding holders of OLs77-02A Potential Heavy 2-16-77 All affected Spring Flooding holders of C?s 77-03 Fire Inside 2-28-77 All holders of a Motor Control OLs and cps Center 77-04 Inadequate Loch 3-17-77 Safeguard Group Assemblica I, II, IV, V, Licensecs 77-05 Liquid Entrapment 3-24-77 All holders of in Valve Bonnets OLs and cps 77-06 Effects of Hydraulic 4-1-77 All holders of Fluid on Electrical OL's and CPc Cabic 77-07 Short Period During 4-12-77 Holders of Reactor Startup BWR OLs 77-08 Failure of Feedwater 4-13-77 All holderc Sampic Probe of OLs 7,7-09 Improper Fuse 5-25 All holdarc of Coordination In BI'R BWR OLs or cps Standby Liquid Control Syctem Control Circultu 77-10 Vacuum Conditionc 7-15-77

.All holders of Rcoulting in Damage to OLu Liquid Proccau Tanks Encionurc Page 1 of 2

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LISTING OF IU CIRCULARS. ISSUED Ill 1977 (Continued)

CIRCULAR SUBJECT FIRST DATE OF ISSUED TO NO.

ISSUE 77-11 Leahace of Con-9-6-77 All holders of O'_s tainment Isolation and cps Valves with Resilient -

Seats 77-12 Dropped Fuci Assen-9-15-77

-All holders of T..7.

blics at EWR Facili--

OLs or cps tics t

Enclosure Pal;c 2 of 2 i

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