ML17271A200

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NEI 96-07, Appendix D with Hsi Edits from Sep 19-21, 2017 Meeting
ML17271A200
Person / Time
Site: Nuclear Energy Institute
Issue date: 05/16/2017
From:
Nuclear Energy Institute
To:
Division of Policy and Rulemaking
References
DPR Log 2990, NEI 96-07
Download: ML17271A200 (13)
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Text

451 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 i Example 4-4. Digital Modification that Satisfies Dependability, . causing NO ADVERSE IMPACT on a UFSAR:.described Design Function An analog recorder is to be replaced with a new microprocessor-based recorder.

The recorder is used for various purposes including Post Accident : Monitoring, which is a UFSAR-described design function.

' Dependability Assessment:

An engineering evaluation performed as part of , the technical supporting the digital modification concluded that . the new recorder will be highly dependable (based on a quality development , process, testability, and successful operating history) and therefore, the risk of failure of the recorder due to software is considered very low. The change will have NO ADVERSE IMPACT on any design function due to

  • the dependability assessment. , ... -.. **. ---*.-*** . . --**-,, ---*-**------------------
  • 1 452 4.2.1.2 o(_(jh!lng(l_s to as i_n_ the 453 SCOPE 454 If the digital modification does not include or affect a Human-Svstem 455 Interface (e.g .. the replacement of a stand-alone analog relav with a digital 456 relav that has no features involving personnel interaction and does not feed 457 signals into any other analog or digital device). then this section does not 458 *apply and may be excluded from the Screen assessment.

459 In NEI 96-07. Section 3.11 defines procedures as follows: 460 " ... Procedures include UFSAR descriptions of how actions related to 461 system operation are to be performed and controls over the performance 462 of design functions.

This includes UFSAR descriptions of operator 463 action sequencing or response times. certain descriptions

... of SSC 464 operation and operating modes. operational

... controls.

and similar 465 information." 466 Although UFSARs do not typically describe the details of a specific Human-467 System Interface.

UFSARs will describe anv design functions associated with 468 the HSI. 469 Because the human-svstem interface (HSI) involves svstem/component 470 operation, this portion of a digital modification is assessed in this Screen 4 71 consideration.

The focus of the Screen assessment is on potential adverse 4 72. effects due to modifications of the interface between the human user and the 4 73 technical device. D-22 -Comment [A42]:.Comments on-HSI Screening Guidance were provided in: (1) ML17068A092 Comment Nos. 18-26 (2) ML17170A089 Comment Nos. A17-A27 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 rr-** -**** ---..

    • -* -*---**--------------* ---------*---.

here are 3 "bas1c HSI elements" (

Reference:

NUREG-0700):

  • *
  • to monitor and control the pl'antJ 'controls:

the devices through ill"t;1:act with.-th.e-H:sf

'and the plant.! luser-interfaC"e-

h
ich personnel provide inputs to an interface, receive information from itJ 'and manage the tasks associated with access and control of information:!

__________ ___________________________________ * -Operators must be able to accurately perceive, comprehend and respond to svstem information via the HSI to successfullv complete their tasks. Specifically, nuclear power plant personnel perform "four generic primarv tasks" 6947): * (1) (2) (3) (4) monitoring and detection (extracting information from the environment and recognizing when something changes), situation assessment (evaluation of conditions).

response planning (deciding upon actions* to resolve the situation) and response implementation (performing an action). To determine potential adverse impacts of HSI modifications on design functions, a two-step analysis must be performed.

Step one is assessing if and in what way hew the modification impacts (i.e., positively, negatively or no impact) the operators' abilities to perform each of the four primary types of tasks described above. If the:re a:re negatwe impacts; stepStep two of the analvsis consists of determining if and how the impacts, identified in step one, affects the pertinent UFSAR-described design functi6n(s) (i.e., adversely or not adversely).

E1ramples of Examples of nH:egative impacts on operator performance of tasks that may result in adverse effects on a design function include but are not limited to:

  • increased possibilitv of mis-opei:ation,
  • increased difficulty in evaluating conditions.
  • increased difficulty in performing an action.
  • increased time to respond,
  • creation of new potential failure modes.
  • Table 1 contains examples of modifications to HSI elements that showd be addl'essed in the :response to this Se:reen eonside:ration.

[INSERT TABLE 1 FROM HSI COMMENTS FILE HERE.] In NEI 96 07, Section a.11 defines pmeed1bres as follows: D-23 Comment [DA4l]: Ciarlfication:

Thnk of , ' "these elements as a way to' define the entirety, * "of what comprises and.HSI. Some modifications may not fall neatly into one category, but if it falls Within any or all of . these categories, it is HSI related.

515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 NEI 96-07, Appendix D Nlj:I Proposed Modifications:

May 16, 2017 " ... Proced"tbres incl"tbde UFSAR descriptions of how actions related* to S)'stem operation are to /:Je perfonned and controls over the perforRianee

&f design functions.

This includes UFSAR deseriptimis

&f operator action seq"thenein,g or response 'times, certain descriptions

... &f SSC operation and operating modes, operational

... controls, and similar i1ifonnation."

  • Because the loluman System lnterfaee involves S'{Stem/com13onent 013eration, 013erator actions, res13onse times, etc., this 13ortion of a eligital moelification is assesseel in tl'lis Screen consieleration.

If the digital modifieation does not inelude m* affeet a Human System Inte1-faee (e.g., the replaeement of a stand alone analog relay with a digital i*elay that has no featm*es involying personnel interaetion and does not feed signals into any oth01* analog or digital de'.'ice), then this seetion does not apply and may be mrebded from the Sereen assessment.

The foeus of the Sereen assessment is on potential adve1*se effects due to modifications of the in.tm'faee between the human us01* and the technical device [e.g., equipment manipulations, actions taken, options ar;ailable, decision making, manipulation sequenees 01* operato1*

i*esponse times (including the impact of e1*ro1*s of a eognitive nature iH which the information being provided is unelear m* iHeon*eet)], nfil the V.'ritteE:

p:rneedUl'e modificatioHs that may accompaHy a physical design modificatioE: (which m*e add1*essed iH the guidanee provided in NEI 96 07, Seetion 4.2.1.2).

PHYSICAL INTERFACE WITH THE HUl\1 fAN SYSTEM I:NTERF.t',CE In the determination of potential adverse impaets, the following aspeets should be addressed in the 1*esponse to this Sernen eonsideration: (a) Physical Intometion with the Human System Intm*faee (HSI) (b) Numbm*/Type of Parametel'S (e) Information P1*esentation (d) Op01*ato1*

Response Time Physical Interaction with the HHman System Interface l', typical physical iHternctioE:

modificatioH might involve the. use of a touch sci:*een in place of push buttons, switches m* knobs, including sensm*y based aspects sueh as auditory or taetile feodbaek.

  • D-24 r*

548 549 550 551 552 553 . 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 582 583 ---l NEI 96-07 .. Appendi:x D NEI Proposed Modifications:

May 16, 2017 . . . h "e an adverse d. ital mod1fieat10n_a

  • due to the . ggr aspeets of a1g . otential impacts To determine design in the Sc1*een .. impact on UF "'. "'th the IISI shouL e . l interaet1on n 1 phys1ea Consideration of a digital modifieation's impaet due to the physieal interaetion with the IISI involves an mmmination of the aetual physieal interface and how it could impact the perfo1*mance and/01* satisfoetion of UFSAR deseribed design funetions.

Fm* mrample, if a new malfunetion is m*eated as a result of the physieal interaetion, then the IISI portion of the digital modification would be adverse. Such a IlO'N malfunction may be crnated by the interfaee requiring the human user to choose whieh of multiple eomponents is to be contrnlled, e1*eating the possibility of selecting the \Vrong component (which could not occlil' with an analog system that did not need the human use1* to "make a selection").

Charactm*istics of IISI changes that could lead to potential adverne effects may include, but are not limited to:

  • Changes from manual to automatic initiation (01* vice versa) of functions, . g an edgewise h as replacm h' h . . . roeess (sue GRT in w ic . data aeqms1tioi_i p . i* a multipurpose Changes ill the *::a numm*ic d1spla': o . t"on to display),
  • analog.mete1*

wit a .. es operator intmac i "Af>IO&'ttto:rrothe data i*eqmr access . the interaction of t' . 1 faillll'e modes ill . . t W" poten ia

  • hips 01 es that crea e n " / m intel'l'elatwns . nem " Chang . m4h the system (e.g., n?" di . plant respoase, o1 " opm*atm:s .d t 1. actwas an 01 . ) "tm*dependencies of o lant status info1*mation., ill the op01*at01*

ass1m1lates p ways

  • Inm*eased possibilit . f . . function, Y 0 llllS operatwn rnlated to *f .

a design

  • Increased difficulty for an operat01*

to perform a design fuactioa, 01*

  • Increased complexity m* duration in diagnosing 01* i*esponding to an accident [e.g., Tiffie Cl'itical Operation 1\ctions (TCO,ALs) identified in the UFSlLR]. If the mn h .c anges do note *h"b' then it may be re k JAt eharacte1*istics such . controlling" a d e?nclude that the "moth :s ;hose hst?d abO\'O, OSl.,n functwn lS not ad"ers 1 f£ o o performillg 01*
  • a
  • Examples 4-5 through 4 7 illustrnte the application of the Physical Interactimi aspect illustrates how to apply the assessment tn*ocess to ONLY the "controls" element of an RSI.is process to an rnHSI modification i Example, Pkysieal with.
  • D-25 ,, '* ..

,.-NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 i NO ADVERSE IMPACT on a UFSAR-Described Design Function ' Description of the Proposed .Aetivity Iavslviag the Csatrsl i ElemeatModification:

Currently, a knob is rotated clock-wise to mm*ease a esntrsl functisn open a i flow control valve in 1% increments and counter clock-wise

_to dem*ease -[ esnti:*sl funetisnclose a flow control valve in 1 % increments.

This knob will be : replaced with a touch screen that has two separate arrows, each in its own ; function block: __ Using the screen, touching the "up" arrow will increase i the eontrsl functisn open the flow control valve in 1 % increments and : touching the "down" arrow will dec:l:'Oase the central functisnclose the flow i control valve in 1 % increments.

I . ' Identification and Assessment of the Four Generic Primary Tasks Potentially

Impactedinvslved:

! (1) monitoring and detection (extracting information from the environment

and recognizing when something changes) -NOT INVOLVED : (2) situation assessment (evaluation of conditions)

-NOT INVOLVED i (3) response planning (deciding upon-actions to resolve the situation)

-NOT , INVOLVED ; (4)ocesponse implementation (performing an action) -

__ , __ j , , , ' .,, , ' *; Desiga FHaetisa Ideatifieatisn:

' . . : The UFSAR deseribed desigH: fuactisn states the Bf!eratsr caF.i "merease G:I'l:d : deerease the control functisns Hsing manHal esatrsls lseated in the Main ! Cantrel Reem.'.' ThHs, this UFS1A..R deseriritio:R imrilicitly ideatifies the SSC i (i.e., the and the desigH:-function of the SSC (i.e., its ability to allow the : orierator to manHally adjast the eoat*l'Ol funetioa).

' ! Identifieation aad Assessment of Modification Impacts on the Four Generic Primary Tasks INVOLVED:

i , As part of the technical evaluation supporting the proposed , aetivitymodification,*a Human Factors Evalµation (HFE) was performed.

Tasks L2 and 3 are not involved therefore they do not have negative impacts. Task 4 is involved, but the HFE determined that the change from knob to touch screen was not going to have a negative impact on the operator because--;;-;there was no change to the ability of the operator to perform the response implementation*task-.

The HFE eonelHded that no new failares OF malfonetions have beea iatFsdHeed as a Fesl:ilt of the refllaeemeat a knob to a toHeh sei*een. D-26 Comment [DA44]: Response" implementation is the only task that would lie pertinent here as it changes the 584 585 586 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 !Possibility of mis opeFation NO IMPACT difficulty in w;aluating conditions 1'Yfi diffieulty in peFfoFming an aetion NO IMPfiCT time to respond N/.,.'\ new potential foiluFe modes NO IMPAC] _______________

_ Identification of the Relevant Design Function(s):

The UFSAR design function states the operator can "incl'ease and decrease the control functions open and close the flow control valve using manual controls located in the Main Control Room." Thus, this UFSAR description implicitly identifies the SSC (i.e .. the knob) and the design function of the SSC (i.e., its ability to allow the operator to manually adjust the functionposition of the flow control valve). Assessment of Impact(s) on Design Function Impaet(s)

Using the results from the HFE and examining enly-the physieal internetion aspeet "contrnls" element of an HSI (e.g., ignoring the impaet on operator response time 01* the numbeF and!oF sequence of steps necessary to aceess the new digital eontrolsthe other thi*ee HSI elements), the replacement of the "knob" with a "touch screen" is not adverse since it does not impact the ability of the operator to "incl'Oase open and close the flow control valve using manual controls located in the Main Control Room," maintaining satisfaction of the UFSAR-described design function.

Using the same proposed activity provided in Example 4-5, Example 4-6 illustrates how a variation in the UFSAR description would cause an adverse impact. Example 4-6. Physical Interaction with an ADVERSE IMPACT on a UFSAR-Described Design Function The UFSAR states not only that the operator can "increase and decrease the control functions using manual controls located in the Main Control Room," but also that "the control mechanism provides tactile feedback to the operator as the mechanism is rotated through each setting increment." Since a touch screen cannot provide (or duplicate) the "tactile feedback" of a mechanical device, replacing the "knob" with a "touch screen" is adverse because it adversely impacts the ability of the operator to obtain tactile feedback from the device. D-27 -Comment [DA45]: These are only some of the possible negative impacts , thus, listing them here makes it appear that these are the ONLY outcomes that should be considered, Again, we do not want to get in a situation where we are tiying to list all the possibilities.

NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 587 Using the same proposed activity provided in Example 4-5 and the same 588 UFSAR descriptions from Example 4-6, Example 4-7 illustrates how a 589 variation in the proposed activity would also cause an adverse impact. 590 Example 4-7. Physical Interaction with an ADVERSE IMPACT on a UFSAR-Described Design Function In addition to the touch screen control "arrows" themselves, a sound feature and associated components will be added to the digital design that will emit a clearly audible and distinct "tone" each time 'the control setting passes through the same setting increment that the tactile feature provided with the mechanical device. Although the operator will now receive auditory "feedback" during the operation of the digital device, the means by which this feedback is provided

  • has been altered. Since the means of controlling the design function has changed, new malfunctions can be postulated (e.g., high ambient sound levels that prevent the operator from hearing the feedback).

Therefore, the modification of the feedback feature (i.e., from tactile to auditory) has an adverse impact on the ability of the design function to be performed.

591 Number and/oF Type of PaFametei*s Displayed By and/oF 1\vailable 592 FFom the Human System InteFfaec 593 One advantage of a digital system is the amount of information that can be 594 monitored, stored and p1*esented to the aser. Hov,rever, the possibility C](ists 595 that the amount of such information may lead to an efJer aln-mdancc that is 596 not neeessa1*ily beneficial in all eases. 597 To detm*mine if the HSI aspects of a digital modification have an adverne 598 effect on UFSli:R described design functions, potential impacts due to the 599 number and/01* type of parameters displayed by and/or available from the 600 HSI shoald be add1*essed in the Semen. 601 Considei:*ation of a digital modification's impact dae to the number and/m* 602 type of parameters displayed by and/el' available from the HSI involves an 603 mmmination of the actual numbm* and/or type of parametern displayed by 604 and/ol' available from the HSI and how they coald impact the perfm*mance 605 and/or satisfaction of UFSAR dese1*ibed design functions.

Potential causes fo1* 606 an adverne impact on a UFSAR described design function could include a 607 in the number of pawmetern monitored (whieh coald make the 608 diagnosis of a prnblem Ol' detern1ination of the prnper action morn challenging 609 or time consuming for the opemtm*), the absence of a prnviously available 610 paramete1* (i.e., a type of pm*ametm*), a differnnee in how the loss m* failm*e of D-28 611 612 613 614 615 616 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 pm*ametern occ::rn (e.g .. as the i*esult of combining pm*an1etern), 01* an inernase in the amount of infornrntion that is p1*ovided sueh that the amo::nt of available infonnation has a deti*imental impact on the opemtor's ability to discern a pm*ticulm*

plant condition 01* to pm*fonn a specific task. EJmmple 4 8 illustrates the application of the l'lumbcr and/er Type ef Parameters aspect. Example 4-8. Number and Type of Parameters with NO ADVERSE IMPACT on a UFSAR-Described Design Function Currently, all controls and indications for a single safety-related pump are analog. There are two redundant channels of indications, either of which can be used to monitor pump performance, but only one control device. For direct monitoring of pump performance, redundant motor electrical current indicators exist. For indirect monitoring of pump performance, redundant discharge pressure and fiow rate indicators exist. Furthermore, at the destination of the pump's flow, redundant temperature indicators exist to allow indirect monitoring of pump performance to validate proper pump operation by determination of an increasing temperature trend (i.e., indicating insufficient flow) or a stable/decreasing temperature trend (i.e.,

  • indicating sufficient flow). All of these features are described in the UFSAR. The UFSAR also states that the operator will "examine pump performance and utilize the information from at least one of the redundant plant channels to verify performance" and "the information necessary to perform this task is one parameter directly associated with the pump (motor electrical current) and three parameters indirectly associated with pump performance (discharge pressure, flow rate, and response of redundant temperature indications)." A digital system will replace all of the analog controls and indicators.

Two monitoring stations will be provided, either of which can be used to monitor the pump. Each monitoring station will display the information from one of the two redundant channels.

The new digital system does not contain features to automatically control the pump, but does contain the ability to monitor each of the performance indications and inform/alert the operator of the need to take action. Therefore, all pump manipulations will still be manually controlled.

Since the new digital system presents the same number (one) and type (motor electrical current) of pump parameters to directly ascertain pump performance and the same number (three) and type (discharge pressure, flow rate and redundant temperature) of system parameters to indirectly ascertain pump performance, there is no adverse impact on the UFSAR-D-29 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017

  • described design function to perform direct monitoring of pump performance and no adverse impact on the UFSAR-described design function to perform
  • indirect monitoring of pump performance.

Information Presentation on the Human System lnterfaee A typical change in data prnsentation might result from the i*eplacement of an edgewise analog mete1* with a nume1*ic display m* a multipurpose CRT. To cletennine if the HSI aspects of a digital modification have an adv01*se effect on UFSl'iR desc1*ibed design functions, potential impacts due to how the infm*mation is p1*esented should be addressed in the Screen. Considerntion of a digital modification's impact due to hovi' the infm*mation is presented involves an examination of how the actual infm*mation presentation method could impact the p01*fo1*mance and!m* satisfaction of UFSAR described design functions.

To determine possible impacts, the UFSi\R should be reviewed to identify descriptions 1*egarding how infonnation is presented, organized (e.g., how the info1*mation is physically prnsented) 01* accessed, and if that presentation, organization or access relates to the pm*formance and/or satisfaction of a UFSL\R described design function.

Examples of activities that have the potential to cause an adverne effect include the following activities:

  • Addition or i*cmoval of a dead band, or
  • Replacement of instantaneoas i*eadings with time avcmged readings (or vice verna). If the HSI changes do not exhibit chamcte1*istics such as those listed above, then it may be rnasonable to conclude t,hat the "method of pm*fol'ming or cont1*011ing" a design function is not ad1101*sely affected.

Example 4 9 illustrntes the application of the Information Presentation Example 4-9. Information Presentation with an ADVERSE IMPACT on a UFSAR-Described Design Function : A digital modification consolidates system information onto two flat panel displays (one for each redundant channel/train).

Also, due to the increased precision of the digital equipment, the increment of presentation on the HSI will be improved from 10 gpm to 1 gpm. Furthermore, the HSI will now D-30 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 present the information layout "by channel/train." The UFSAR identifies the existing presentation method as consisting of "indicators with a 10 gpm increment" to satisfy safety analysis assumptions and the physical layout as being "by flow path" to allow the operator to

  • determine system performance . . The increase in the display increment is not adverse since the operator will continue to be able to distinguish the minimum increment of 10 gpm described design function.

The new display method (i.e., "by channel/train")

adversely affects the ability of the operator to satisfy the design function to ascertain system performance , "by flow path." OpeFator Response Time Typieally, an inm*ease in the operntor i*esponse time might i*esult from the need fm* the opemtor to pm*fonn additional actions (e.g., due to the additional steps necessary to call up or ret1*ieve the appropriate display and operate the "'soft" eontrnl rnthm* than merely reading an indieatm*

on the :Main Cont1*ol Boa1*d). To detm*mine if the HSI aspects of a digital modification have an advcrne effect on UFSAR described design funetions, potential impacts on the operntor response time should be addressed in the Sei*een. Consideration of a digital modification's impact on the operator 1*esponse time due to the modification of the numbe1* and,lor type of decisions made, and/or the modification of the munbm* and/01* type of aetions taken, involves an examination of the actual decisions made/actions taken and how they eoald impact the performance and/or satisfaction of UFSAR described design knctions.

To detm*mine possible impacts, the UFSAR must be i*eviewed to identify desc1*iptions i*elating to operntor response time requfrements and if those timing req:1irnments ai*e i*elated to the performance and/m* sntisfaction of a UFSl,R described design fanction.

Example 4 10 is the same as Example 4 9, but illustrntes the application of the Operator Response Time aspect. , Example 4-10. Operator Response Time with NO ADVERSE IMPACT on a UFSAR-Described Design Function

  • A digital modification consolidates system information onto two flat panel D-31 666 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 : displays (one for each redundant channel/train).

Also, due to the increased

  • precision of the digital equipment, the' increment of presentation on the HSI ! will be improved'from 10 gpm'to 1 gpm.

tlie HSI will now ; present the information lay.out "by channel/train." 1 The UFSAR identifies the existing presentation method as consisting of the physicarlayout as being "by flow path" to allow the operator to*determine. , system performance.

  • . Although the UFSAR identifies the existing presentation method as i consisting of a physical layout "by flow path" to allow the operator to : determine system performance and the new display method (i.e., "by : channel/train")

will require additional steps by the operator to determine 1 system performance, requiring more time, there is no adverse impact on : satisfaction of the design function to ascertain system performance because l no time requirements are applicable to tlie design function*

of the i operator being able "to determine sy!ltem performance.

' ' ' 667 COMPREHENSIVE HUMAN-SYSTEM INTERFACE EXAMPLE 668 Although no additional guidance is provided in this section, Example 4-11 669 illustrates how each of the aspects identified above would be addressed.

Example 4-11. Digital Modification involving Extensive HSI 1 Considerations with NO ADVERSE IMPACTS on a UFSAR-Described 1 Design Function.

'. Component controls for a redundant safety-related system are to be replaced ' with PLCs. The existing HSI for these components.is made up of redundant

hard-wired switches, indicator lights, and analog meters. The new system l consolidates the information and controls onto two flat panel displays (one : per redundant train), each with a.touch screen providing "soft" control ! capability.

' I The existing.number and type. of parameters remains the same, which can be 1 displayed in a mau"ner similar to the existing presentations (e.g., by' train). ; However, information can be also in different configurations

that did not previously exist (e.g., by path or by parameter type to allow for easier comparison of like paramete;rs), using selectable displays.

The flat panel display can also present any of several selectable pages depending on the activity being performed by the operator (e.g., starting/initiating the monitoring the system during operation, or D-32 changing the system line-up).

NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017 To operate a control, the operator must (via the touch screen) select the appropriate activity (e.g., starting/initiating the system, monitoring the system during operation, or changing the system line-up), select the desired page (e.g., train presentation, path presentation, or parameter comparison), select the component to be controlled (e.g., pump or valve), select the control action (e.g., start/stop or open/close), and execute it. The display remains on the last page selected, but each page contains a "menu" of each possible option to allow direct access to any page without having to return to the "main menu." The two new HSis (one per redundant train) will provide better support of operator tasks and reduced risk of errors due to:

  • Consolidation of needed information onto a single display (within the family of available displays) that provides a much more effective view of system operation when it is called into action.
  • Elimination of the need for the operator to seek out meter readings or indications, saving time and minimizing errors.
  • Integration of cautions and warnings within the displays to help detect and prevent potential errors in operation (e.g., warnings about incorrect system lineups during a test or maintenance activity).

The design was developed using a human factors engineering design, with a verification and validation process consistent with current industry and regulatory standards and guidelines.

As part of the technical evaluation supporting the proposed activity, a Human Factors Evaluation (HFE) was performed.

Based on the conclusions from the HFE, the design provides a more effective HSI that is less prone to human error than the existing design. The UFSAR-described design functions applicable to this proposed activity include desm*iptions of how the existing controls, including the physical switches, indicator lights and meters, and how each of these SSCs is used during normal and abnormal (including accident) operating conditions.

The UFSl\R identifies the current physical arrangement (i.e., two physically separate locations) assurance that the design function is satisfied bv preventing the operator that prnvents the operntor from operating the "wrong" component.

There are no UFSAR-described design functions related to the operator response times associated with using the existing controls.

The impacts on design functions are identified below: D-33 670 NEI 96-07, Appendix D NEI Proposed Modifications:

May 16, 2017

  • Physical Interaction

-NOT ADVERSE because the new HSI consists of two physically separate displays.

  • Number and Type of Parameters

-NOT ADVERSE because the same number and type of parameters exist with the new HSI.

  • Information Presentation

-NOT ADVERSE because all of, the existing features (e.g., individual controls, indicator lights and parameters displays that .. mimic the analog meters) continue to exist with the new HSI. Operator Response Time -NOT ADVERSE because no response time requirements were applicable to any of the design functions and there were no indirect adverse affects on any other design function.

671 4.2.1.3 Screening Changes to UFSAR Methods of Evaluation 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 4.2.2 687 688 689 690 691 -692 693 By definition, a proposed activity involving a digital modification involves SSCs and how SSCs are operated and controlled, not a method of evaluation described in the UFSAR (see NEI 96-07, Section 3.10). Methods of evaluation are analytical or numerical computer models used to determine and/or justify conclusions in the UFSAR (e.g., accident analyses that demonstrate the ability to safely shut down the reactor or prevent/limit radiological releases).

These models also use "software." However, the software used in these models is separate and distinct from the software installed in the facility.

The response to this Screen consideration should reflect this distinction.

A necessary revision or replacement of a method of evaluation (see NEI 96-07, Section 3.10) resulting from a digital modification is separate from the digital modification itself and the guidance in NEI 96-07, Section 4.2.1.3 applies. Is the Activity a Test or Experiment Not Described in the UFSAR? By definition, a proposed activity involving a digital modification involves SSCs and how SSCs are operated and controlled, not a test or experiment (see NEI 96-07, Section 4.2.2). The response to this Screen consideration should reflect this characterization.

A necessary test or experiment (see NEI 96-07, Section 3.14) involving a digital modification is separate from the digital modification itself and the guidance in NEI 96-07, Section 4.2.2 applies. D-34

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