ML19336D484
| ML19336D484 | |
| Person / Time | |
|---|---|
| Issue date: | 02/26/1991 |
| From: | Munro J Office of Nuclear Reactor Regulation |
| To: | Roe J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19336D485 | List: |
| References | |
| NUDOCS 9103050518 | |
| Download: ML19336D484 (3) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
l W ASHINGTON, D. C. 20555 February 26, 1991 MEMORANDUM FOR: Jack W. Rot, Director Division of Licensee Performance and Quality Evaluation, NRR THRU:
obert M. Gallo, Chief erator Licensing Branch vision of Licensee Performance
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and Quality Evaluation, NRR William Dean, Chief Regional Support and Oversight Section (9
Operator Licensing Branch Division of Licensee Performance and Quality Evaluation, NRR FROM:
John Munro, Panel Chairman Regional Support and Oversight Section Operator Licensing Branch Division of Licensee Performance and Quality Evaluation, NRR
SUBJECT:
SIMULATOR SCENARIO ASSESSMENT In a memorandum dated January 24, 1991, William Dean directed the review of selected simulator scenarios to evaluate simulator scenario consistency. details the methodology utilized in the assessnient. A panel consisting of six certified examiners (J. Munro, J. Pellet L. Miller, I.
Kingsley, F. Victor and D. Draper) reviewed sixty-six (66), scenarios representative of eleven requalification examinations. The requalification rcenarios were assessed for consistency by evaluation of the following content areas:
o ISCT identification per NUREG-1021, Rev. 6 criteria o
Malfunctions, number and sequencing o
Events, abnormal and major o
E0Ps, number and time of usage The results of this assessment are tabulated in Enclosure 2.
By reviewing the data and incorporating judgements on the scenarios by the panel of examiners, several important conclusions are highlighted.
m o
Scenario complexity varies by facility rather than by Region. Note 3
the difference in data between Facilities A and B.
o-The panel concluded that counting ISCTs, malfunctions or other cn,
o "n2o discrete scenario variables was not always indicative of complexity.
Scenario complexity was determined to be a function of event sequencing and requirements for operator action (s) in the E0Ps.
o4 Specifically, activation of malfunction (s) after initial E0P entry
@g complicates the mitigation strategy and increases operator usage of j' -.q /, 'lb 55 l 29v.110 Fa EE CEidIEil COP'l
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E0Ps and associated contingency procedures. Enclosure 3 provides a comparison of the evaluation scenarios provided by two facilities for a Design Basis Accident LOCA.
Many ISCTs are not be kg properly identified in accordance with the o
most recent Examiner Standards guidance.
ISCTs are tasks which, if omitted or incorrectly performed by an operator, will result in adverse consequence (s) which significantly alter the event mitigation strategy to the detriment of plant or public safety. The panel identified numerous tasks that did not meet this definition or the criteria for critical tasks detailed in ES-604, Rev 6,.
The panel also identified some additional scenario tasks that met the criteria for ISCTs.
In many instances, the tasks had been identified for evaluation but not as critical, e.g., trip of RCPs during LOCA. Enclosure 4 provides r sample of ISCTs that the panel determined should be either deleted or added to the reviewed scenarios.
The panel recomends that the following programatic changes and clarifications be implemented to better assure examination consistency.
Specify that one scenario have the operators enter and perform o
safety related tasks (ISCTs) in AOPs and E0P contingency procedures.
Specify that the second scenario also perform ISCTs in A0Ps and E0Ps; however, entry into the E0P contingency procedures "by design" would be precluded. Two scenarios will normally provide an adequate scenario set for a four person operating crew consisting of two SR0s
- and two R0s. Perform both scenarios with the operators manning their normal shift positions.
o Specify that the scenario planned for the usage of E0P contingency procedure (s) expend 50 - 60 percent of scenario run time or twenty--
five to thirty (25 - 30) minutes in the usage of these E0Ps. The second scenario should be designed to expend 30 - 40 percent of scenario run time or fifteen to twenty (15 - 20) minutes in the usage of E0Ps.
Specify that scenario sets be reviewed for sufficient tasks to allow o
for evaluation of all rating factors (1, 2 or 3) associated with each competency on the Simulator Crew Evaluation Foni. Specifically, the tasks should be designed such that improper crew action (s) (or omission of crew action (s)) will result in some degree of degradation of the facility or adverse effect to the public.
Review the rotation practices for a staff crew of four to five SR0s.
o Currently, the operators rotate through all crew positions.
Requiring four to five scenarios exposes each operator to a high number of ISCTs and requires extensive simulator examination time.
Specify that the safety significance or adverse consequence (s) be o
provided with the scenario for all identified ISCTs. Reemphasize to all examiners and facilities that all ISCTs must possess the four criteria discussed in ES-604, Attachment 1.
i
! o Add clarification to the existing Standard to preclude " generic" designation of ISCTs.
Indicate.the following examples of generic tasks to be unacceptable as critical tasks i
Verification of automatic actions.
Enter ar.d perform E0Ps and E0P transitions.
Enter and classify the Emergency Plan for an Unusual Event.
Enter and take action in accordance with Technical Specifications, t
All of the above operator tasks may be considered ISCTs when the specific actions are listed and the task is evaluated for safety significance within the context of a particular scenario. The 7
following examples of tasks are acceptable as ISCTs:
SR0 directs initiation of Drywell Sprays when torus pressure exceeds 13 psig in accordance with E0P-2.
Transfer Terry Turbine steam supply from steam generator l'1 to #4.
i Declare a Site Area Emergency based on RCS leak greater than make-up capacity.
The Examiner Standards specify that the NRC and facility evaluators review scenarios to assure they are neither too complex nor too simple. The guidance was written with sufficient latitude to incorporate differences in E0P content, simulator capability and professional judgements on depth of coverage. The result has been an inconsistent approach to simulator scenario development.
o This problem is exemplified by the identification of ISCTs that in 45 percent of the cases did Hot adhere to the guidance in ES-604, revision 6.
The recommended corrective action is to provide more specific guidance, as stated above, thereby improving the cbjectivity and consistency of examination scenarios.
$l John F. Munro, Panel Chairman l
Regional Support and Oversight Section Operator Licensing Branch Division of Licensee Performance i
ano Quality Evaluation, NRR
Enclosures:
As stated DISTRIBUTION: OLB RF 4 Central Files JFMunro WMDean RMGallo Ti'Szymar.s ki C0 Thomas JMLanning DJLange FC
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91 OFFICIAL RECORD COPY
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