ML19323A259
| ML19323A259 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/26/1980 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Ahearne J, Gilinsky V, Kennedy R NRC COMMISSION (OCM) |
| Shared Package | |
| ML19323A260 | List: |
| References | |
| NUDOCS 8004180154 | |
| Download: ML19323A259 (7) | |
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UNITED STATES
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NUCLEAR REGULA TORY COMMISSION
- E WASHINGTON D. C. 20555
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March 26, 1983 MEMORA'NDUM Fd?.:
Chairman Ahearne Comissioner Gilinsky Comissioner Kennedy Commissioner Hendrie Comissioner Bradford FROM:
Harold R. Denton, Director j'
Office of Nuclear Reactor Regulation
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William J. Dircks Acting Executive Director for Operations
SUBJECT:
CONSIDERATION OF OPERATING LICENSE FOR NORTH ANNA POWER STATION, UNIT NO. 2 The Staff has nearly completed its review of North Anna Power Station, Unit No. 2.
Our review, which is documented in the enclosed draft Supplemental Safety Evaluation Report (SSER), includes disposition of the residual pre-TMI issues (some of which were discussed in our SER, NUREG 0053 of June 1976) and the list of requirements for Near Term Operating Licenses (NTOL) which was based on consideration of the actions contained in the NRC TMI Action Plan.
At this time, there is one remaining outstanding issue related to issuance of
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a SY, full power license to the North Anna facility. This issue concerns the design of the control room from a human factors standpoint. The NRC Staff, together with its consultants from the Essex Corporation, conducted a 5 day preliminary on-site review of the North Anna Unit 2 control room on March 17-21.
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Staff members participating in the review represented the NRR Instrumentation if and Control, Operator Licensing, Reactor Systems, and Analysis Branches. The l
objective of this review was to assess the degree to which the current design reflects specific human factors considerations. The review included the assessment of control and display panel layout, annunicator design, labeling and sequencing of panel components, and the usability and completeness of l
selected emergency procedures. The review was performed by means of detailed inspection of the control panels, interviews with operators, and observation and videotaping of operators as they walked through selected emergency l
procedures.
Our review identified human factor deficiencies in the control room in the areas of noise level, control panel physical layout, meter displays, annunicators, process controllers, lamp test capability and emergency i
procedures. The staff is currently in the process of categorizing these deficiencies into two groups as follows: Category 1, deficiencies which l
can and should be corrected immediately, and Category 2, deficiencies which 9
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are of concern, but may be corrected at a later date.
Corrections of Category 1 deficiencies will be required before license issuance.
Corrections of deficiencies in the second category will require significant control room modifications and will be implemented at a specified later date after both the applicant and the Staff have carefully assessed the impact of the corrections on the operators.
Both Category 1 and 2 will be discussed with the applicant on Friday 5f this week. Specific changes to resolve the CateSory 1 deficiencies will be Y,. ; ;
identified at that time.
g We have concluded that, except for the issue concerning control room design, all necessary requirements for permitting operations up to 5% power have been satisfied. We expect to complete our review of the control room design by Friday, March 28, to the extent that the short term remedial measures needed to be implemented prior to initial criticality will have been specifically defined.
The SSER will be revised to reflect the control room matter and the revisions provided to the Comission on Monday, March 31. We will be prepared to meet n
with the Comission on the operating license for North Anna Station, Unit 2 at that time.
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n Harold R. Denton, Director Office of Nuclear Reactor Regulation
Enclosure:
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ENCLOSURE 1
, NORTH ANNA POWER STATION, UNIT NO. 2 CONTROL ROOM DESIGN REVIEW' i
l As a part of the staff actions following the TMI-2 accident, we will require that all licensees and applicants for operating licenses conduct a detailed control room design review. We expect those reviews to be initiated within the next several months and require over a year to complete. As an interim measure, the NRC staff together with consultants from the Essex Corporation.
conducted a 5 day preliminary on-site review of the North Anna Unit 2 control room. NRC staff members particip; ting in the review respresented the Instrumentation and Control, Operator Licensing, Reactor Systems, and Analysis Branches. The objective of this review was to assess, prior to licensing, the degree to which the design reflects specific human factors considerations. The review included the assessment of control and display panel layout, annunciator design, labeling and sequencing of panel components, and the usability and completeness of selected emergency procedures. The review was performed by means of detailed inspection of the control panels, interviews with operators, and observation and videotaping of operatorias they walked through selected emergency procedures.
Our review identified several human factor deficiencies. The staff is currently in the process of categorizing these deficiencies into two groups as follows:
- 1) deficiencies which are to be corrected prior to criticality.
- 2) deficiencies which are of concern, but may be corrected at a later date.
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It is anticipated that once categorized, corrections of those deficiencies in the second category will require significant control room modifications. They will be implemented only after both the applicant and the staff have Assessed their impact on the operators. The acceptability of licensing florth Anna Unit 2 prior to correcting these deficiencies is based on the extensive training the operators have received and their familiarity with the control room as presently equipped.
Deficiencies Identified During the Control Room Review Although not a complete list at this time, some of the human factors related control room deficiencies identified by the review team are:
j 1.
Control Room Noise Level The control room is fairlycompact which, by itself, should enhance comunica-i tions. However, the background noise is such that nonnal conversational volume is only effective within a short distance. A ventilation duct run-i ning up one end of the Unit 2 control room supplies a continuous high noise background. To this is added periodic announcements over the public address system, the speaker for which is mounted in the ceiling directly over
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the control console. We requested that an operator don a Scott Air-Pak and s
attempt to comunicate with others nearby. Given the background noise in the control room and the inherent design of the facemask, it proved a near j
impossibility for the operator to comunicate.
2.
Control Panel Physical Layout The control panels are confusing to the operator. Meters are laid out in strings and clust,ers such that identifying a particular meter is difficient.
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In some instances, the indication on the vertical panel was in a different location from that which would correspond to the control on the control i
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console. This prevents an easy sweep upward of the eyes from control to indica tor. Vepco has made an attempt to demarcate groups of associated i.
meters to aid the operator in locating a specific meter. However, because of the basic layout of the displays, these 1-ines of demarcation take on fairly abstract shapes.
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Meter Displays Extensive use of vertical meters is made, each of which has a vertical label on the meter face. Vertical labels are difficult to read, at best, and become more difficult when the meter of interest is one of many identical meters butted against each other in a long string.
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Annunciators Except for "first out" capability, there is no indication of the significance of a given annunciator.
In addition, an alarm can clear and the annunciator return to its normal state without the operator being aware of it.
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Process Controllers
- j The Hagan controllers used extensively provide a readout of the demand signal only.
In most cases the operator can determine if the contr,ol manipulation was effective by monitoring the controlled parameter.
In other cases, the operator must wait for a delayed response of the system to the variation i
in the controlled parameter.
In these latter cases, it may be prudent to provide direct indication of the controlled' parameter.
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Lamp Test Capability Except for the annunciators, there is no capability to test the control panel lamps. Hence, there is always room for doubt when an indicating light remains unlit.
Is the bulb burnt out or did the equipment fail to activate?
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7.
Adninistrative Several examples of poor administrative controls exist in the control room.
Labels are peeling off of some indicators and controls, recorder pens are filled with a different color ink from the color of the pen and scales on some recorder chartpaper do not correspond to the scale on the recorder it-sel f.
There does not appear to be good control over control room access. While the review team was present, we observed as many as fifteen others present in the common control room.
8.
Emergency Procedures It does not appear that the emergency procedures have ever been system-atically stepped through on the control boards.
In some cases steps are missing, in other instances important steps and warnings are buried in the notes. Some of the instructions are ambiguous and others call for a precision beyond the capability of the instrumentation.
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Miscellaneous Deficiencies I'
In addition to those items listed above, there are other human fact 6rs related deficiencies scattered throughout the control room. For example, the color red had multiple meanings, depending upon the area of the control boards in which it was used. There were violations of convention noted; for example a switch marked " lower-raise" (convention) immediately above a switch marked " raise - lower" (violation of convention). Several "j" handle switches need to have guard bars insta11ad to prevent inadvertent l
operation. The colors chosen for some of the labels (black writing on dark purple background) make it nearly impossible to read.
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These deficiencies and others identified in the final Essex report will be discussed with the applicant in the near future. Categories will be b
assigned and corrective action taken depending on the categories.
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We will make follow up visits to the site to ensure that the applicant has corrected the deficiencies.
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