ML20059J318
| ML20059J318 | |
| Person / Time | |
|---|---|
| Issue date: | 01/25/1994 |
| From: | Zech G Office of Nuclear Reactor Regulation |
| To: | Yeats E NRC OFFICE OF THE SECRETARY (SECY) |
| References | |
| NUDOCS 9401310443 | |
| Download: ML20059J318 (16) | |
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f?+,j NUCLEAR REGULATORY COMMISSION UNITED STATES i
2 WASHINGTON, D.C. 20666-0001 k*****,e8 I
I January 25, 1994 l
MEMORANDUM FOR:
Elizabeth J. Yeates, Chief l
Public Documents Branch i
Office of the Secretary of the Commission FROM:
' Gary Zech, Chief.
Performance and Quality Evaluation Branch
-Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation
SUBJECT:
DRAFT MAINTENANCE INSPECTION PROCEDURE i
Please place this memorandum and the enclosed draft " Maintenance Inspection Procedure XXXXX" in the public document room. A notice will be-placed in the Federal Reaister to inform the public that this inspection l
t procedure will be the subject of a Public Workshop on March 31, 1994.
We expect that many of those who plan to attend the workshop will want to obtain l
a copy of the inspection procedure for review prior to 'the workshop.
t
($h i
Gary Zech, Chief Performance and Quality Evaluation Branch Division of Reactor Inspection and Licensee Performance Office of Nuclear Reactor Regulation cc:
WTRussell CERossi
Enclosure:
As stated 9401310443 940125
'O PDR ORG NRRB
{
PDR,
DRAFT 1
(file 50_65_IP.008) 2 3
DRAFT RPEB 4
5 MAINTENANCE INSPECTION PROCEDURE XXXXX 6
7 8
PROGRAM APPLICABILITY:
2515 9
10 11 XXXXX-01 INSPECTION OBJECTIVES:
12 13 01-01 To verify the implementation of 10 CFR 50.65, " Monitoring the 14 Effectiveness of Maintenance at Nuclear Power Plants" (the maintenance rule or 15 the rule), which will take effect on July 10, 1996.
16 17 01-02 To verify the effectiveness of emergency diesel generator (EDG) 18 maintenance activities associated with commitments made in response to 10 CFR 19 50.63, " Loss of All Alternating Current Power" (the station blackout (SBO) 20 rule).
21 22 23 XXXXX-02 INSPECTION REQUIREMENTS':
24 25 There are three steps in the inspection requirements section. The inspector 26 should perform steps 02.01 and 02.03 at each nuclear power site, and has the 27 option of performing step 02.02 depending on the results of step 02.01. The 28 inspector should perform step 02.02 if the results of the reviews and 29 inspections performed in step 02.01 indicate that licensee maintenance l
30 activities may not be effective.
If these reviaws and inspections indicate 31 that maintenance activities are effective, then step 02.02 need not be 32 performed at that site.
(However, step 02.02 will be performed at all plants 33 inspected during the pilot inspection program).
34 35 02.01 Evaluate Maintenance Effectiveness.
Perform onsite inspection of the 36 condition of plant SSCs and review equipment history records and other 37 available documentation in order to determine if the licensee's maintenance 38 program is effectively controlling the ptrformance and condition of SSCs at 39 that plant.
40 41 02.02 Verify Implementation of the Maintenance Rule.
Perform the following 42 reviews to verify the licensee's implementation of the maintenance rule.
43 44 a.
Goal Settino and Monitorino. 50.65(a)(1). Verify that the licensee has 45 implemented goal setting and monitoring as required by paragraph (a)(1) of 46
'The items listed in this section are not necessarily regulatory 47 requirements unless explicitly stated. They are also not necessarily 48 inspection requirements; the inspector may select some or all of the items 49 listed for review, depending on the intended scope of the inspection and the 50 resources the region has allotted for the inspection.
DRAFT
DRAFT (general guidance cont.)
1 preventive maintenance as descrited is paragraph (a)(2) of the rule. The 2
industry guideline for implementing the rule, NUMARC 93-01, has taken the 3
approach that all SSCs are initially placed under paragraph (a)(2) and are 4
only moved under paragraph (a)(1) if experience indicates that the performance 5
or condition is not adequately controlled through preventive maintenance.
6 However the rule does not require this approach.
Licensees could also take 7
the approach that all (or most) SSCs would be handled under paragraph (a)(1) 8 of the rule and none (or very few) would be handled under paragraph (a)(2) of 9
the rule.
Licensees have the option of taking either approach.
10 11 Anoendix B Not Aeolicable to Non-Safetv-Related SSCs: The scope of the 12 maintenance rule (10 CFR 50.65(b)), includes both safety-related SSCs and non-13 safety-related or balance-of-plant (B0P) SSCs.
As stated in Regulatory Guide 14 1.160 (Ref. 1), it is understood that B0P SSCs may have been designed and 15 built with normal industrial practices that may not have met the criteria in 16 Appendix B to 10 CFR Part 50. The inspector should understand that it is not 17 the intent of the maintenance rule to require licensees to generate paper work 18 to document the basis for the design, fabrication, and construction of 80P 19 equipment. However, all requirements of Appendix B remain in effect for 20 safety-related SSCs that are within the scope of the rule.
21 2
22 Specific Guidance 23 24 03.01 Evaluate Maintenance Effectiveness.
Sources of information that could 25 provide insight on the effectiveness of a licensee's maintenance program 26 include: SALP reports, licensee event reports, NRC inspection reports, 27 equipment maintenance history records, plant performance reviews, reliability 28 and unavailability data, equipment performance or condition trending data, and 29 performance indicator data collected by licensees to meet the requirements for 30 goal setting and monitoring contained in the maintenance rule.
31 32 The inspector shall review a sample of available documented information that 33 could provide insight on the effectiveness of the licensee's maintenance 34 activities. The inspector should select a balanced sample which includes:
35 active and passive systems; mechanical, electrical, instrumentation and 36 controls systems and components; and structures.
The inspector shall also 37 tour the plant and perform a walkdown inspection of the condition of SSCs at 38 the licensee's facility.
During these inspections the inspector should look 39 for signs of leakage, corrosion, excess vibration, loose fasteners or other 40 conditions that could indicate inadequate maintenance.
The inspector should 41 also discuss the plant operating history with licensee personnel responsible 42 for operation and maintenance of the plant.
If, based on these initial 43 reviews, it appears there may be a need to perform further reviews of a 44 licensee's implementation of the maintenance rule, the inspector should 45 proceed by performing the inspection requirements in Section 02.02 of this 46 procedure.
47 48 The specific guidance adds information intended to clarify the 2
49 inspection requirements listed in the Inspection Requirements section (XXXXX-50 02). To correlate the guidance with its associated requirement, the numbered 51 designations used in the Specific Guidance section correspond to the numbers 52 used in the Inspection Requirements section. For example, Section 03.01.a.1 53 provides specific inspection guidance for Inspection Requirement 02.01.a.1.
XXXXX Issue Date:
XX/XX/XX
4 DRAFT
_G_ pal Settina and Monitorina 10 CFR 50.65(a)(1). The licensee is 03.02.a.
I required to set goals and monitor the performance or condition for all SSCs j
2 3
selected or required to fall under paragraph (a)(1) of the rule, j
4 5
1.
Monitorina: The rule requires that licensees monitor performance or condition of SSCs in a manner sufficient to provide reasonable assurance j
6 7
that SSCs are capable of fulfilling their intended functions. This wording is intentionally non-prescriptive and is intended to allow licensees 8
considerable flexibility in the methods used to monitor SSC performance or l
9 10 condition.
11 Risk Consideration in Monitorina: The statements of consideration (a) 12 (Ref. 4) and the regulatory guide (Ref.1) state that the extent of 13 J
14 monitoring may vary from system to system depending on the system's 15 importance to risk (or safety). This determination may be quantitative l
16 or qualitative. Section 9.0 of NUMARC 93-01 (Ref. 2) provides guidance on various methods for establishing which SSCs are risk significant.
l 17 These methods include the use of individual plant examination (IPE) i 18 19 results, plant-specific probabilistic risk assessment (PRA), preventive j
20 maintenance program results, and others.
Guidance is also provided on the use of risk importance measures such as risk reduction worth, core 21 i
22 damage frequency contribution, and risk achievement worth. The 23 licensee may use other methods to determine the risk-significance of 24 SSCs.
25 26 The inspector should verify that the licensee has considered risk when 27 determining the extent of monitoring required. To accomplish this, the 28 inspector should select a sample of SSCs that are within the scope of the maintenance rule and, using the licensee's own criteria, determine 29 if the licensee has identified those SSCs that are risk-significant.
30 31 The inspector should verify that the monitoring for these risk 32 significant SSCs is commensurate with their importance to plant risk.
33 34 (b) Monitorina at the Plant. System. or Train level:
It is expected 35 that most monitoring should be done at the plant, system, or train 36 level, although some monitoring at the component level may be 37 necessary. The three examples listed below are taken from the 38 regulatory guide (Ref.1):
39 40 (1)
For less-risk-significant systems, indicators of system 41 reliability (where sufficient performance data exist) and 42 availability may be all the monitoring that is necessary (i.e.,
43 monitoring the reliability and availability of the overall system 44 provides adequate indication of the performance of the individual 45 components).
46 47 (2) For more-risk-significant systems, some parameter trending may 48 also be required for critical components whose unavailability or 49 failure could cause a system train to be unavailable, or whose 50 failure is otherwise unacceptable.
51 52 (3)
For other SSCs, rather than monitoring the many SSCs that 53 could cause plant scrams, the licensee may choose to monitor 54 unplanned scrams as an indirect means of monitoring performance.
55 55 Additional guidance on acceptable methods of performing monitoring is 57 described in Section 9.4.2. of NUMARC 93-01 (Ref. 2).
Issue Date: XX/XX/XX XXXXX
DRAFT
'(specific guidance 03.02.a. cont.)
1 Having reviewed records and spoken with personnel, the inspector should 2
verify that the licensee has established and implemented adequate 3
performance or conditioning monitoring for all SSCs within the scope of 4
the rule.
J 5
6 (c) Use of Existina Proarams for Monitorina: The regulatory guide i
7 (Ref. 1) states that it is intended that most activities currently 8
being conducted by licensees, such as technical specifications 9
surveillance testing, can be used to satisfy many of the monitoring 10 requirements; and, consistent with the rule, the inspector should allow 11 licensees maximum flexibility in establishing and modifying their i
12 monitoring activities. Additional guidance on the use of existing I
13 programs for monitoring is described in Section 9.4.2 of NUMARC 93-01 14 (Ref. 2). Although licensees are free to initiate any new activities 15 they believe necessary to ensure that SSCs are adequately monitored, 16 the inspector is cautioned not to expect licensees to establish many 17 new activities to satisfy the requirements of the maintenance rule.
18 19 2.
Goal Settina:
Paragraph (a)(1) of the rule requires licensees to 20 establish goals commensurate with safety and, where practical, to take into 21 account industrywide operating experience.
Licensees have a great deal of i
22 flexibility in choosing goals and may elect to choose component, train,
23 system, or plant-level goals. These goals may be performance oriented 24 (reliability, availability) or condition oriented (such parameters as pump 25 flow, pressure, vibration, valve stroke time, current, electrical l
26 resistance).
Licensees should document the bases for the goals and any 27 subsequent changes made to those goals.
Guidance on documentation is 28 provided in section 13.2.1 of NUMARC 93-01 (Ref. 2). The rule specifically' 29 states that the goals are to be " licensee established." Therefore, the 30 inspector should allow licensees maximum flexibility in establishing and 31 modifying their goals. However, the goals must represent reasonable 32 attempts to establish targets for monitoring SSCs within the scope of the 33 rul e.
Licensees should consider the following when setting goals:
34 35 (a) Risk Consideration for Goal Settina: The rule-specifically 36 requires licensees to establish goals commensurate with safety (or 37 risk).
Information on an SSC's contribution to plant safety can be 38 obtained from various sources including the Individual Plant 39 examination (IPE) or probabilistic risk assessment (PRA) results (if 40 available).
Section 9.0 of NUMARC 93-01 (Ref.2) provides guidance on i
41 acceptable methods for establishing risk-significant criteria. These 42 methods include the use of risk reduction worth, core-damage frequency 43 contribution, and risk achievement worth.
Licensees may use these or i
44 other methods to determine risk significance.
45 i
46 The inspector should select a sample of SSCs for which the licensee has 47 established goals and verify, by reviewing licensee records and i
48 speaking with responsible personnel, that risk or safety was taken into 49 account when establishing goals.
50 51 (b) Operatina Experience for Goal Settina: The licensee should also.
52 where oractical, take into account industrywide operating experience 53 when establishing goals.
Sources of industrywide operating experience 54 include, but are not limited to, NRC bulletins and information notices, 55 the Institute of Nuclear Power Operations (INPO) Nuclear plant XXXXX Issue Date: XX/XX/XX DRAFT P
?
DRAFT
-(specific guidance 03.02.a. cont.)
1 reliability data system (NPRDS), vendor technical information letters 2
(TILs), and vendor service information letters (SIls). Although a 3
great deal of failure information is available in the industry in 4
various forms, the availability, accessibility, and usefulness may be 5
limited.
In view of these limitations, the inspector should not expect 6
the licensee to be able to identify all failures of similar SSCs in the 7
industry when reviewing industry operating experience.
8 9
The inspector should verify that the licensee has established and 10 implemented a documented method or process for considering industry 11 operating experience, where practical, when establishing goals.
12 l
13 3.
Corrective Action:
Licensees are required to monitor the performanr.e 14 or condition of SSCs against the established goals and take appropriate 15 corrective action where the goals are not met or where a clearly declining 16 trend in SSC performance or condition indicates the goals would not be met 17 before the end of the next surveillance cycle. Where analysis determines i
18 that the performance or condition of the SSC is acceptable, the licensee 19 may elect to modify the original goals and continue monitoring.
I 20 21 The inspector should select a sample of maintenance monitoring records and 22 compare them to the established goals. Where goals were not met, or where 23 a clearly declining trend in SSC performance or condition is indicated, the 24 inspector should examine the licensee's corrective actions to determine if 25 the root cause was identified, if reasonable corrective action was taken, 26 and if an evaluation of the effectiveness of the corrective action was 27 performed. Licensee activities such as root cause analysis and corrective 28 actions must be documented by the licensee.
29 30 31 03.02.b.
Preventive Maintenance. 50.65(a)(2). The maintenance rule states 32 that monitoring as specified in paragraph (a)(1) is not required if it has 33 been demonstrated that the performance or condition of an SSC is being 34 effectively controlled through the performance of appropriate preventive 35 maintenance so that the SSC remains capable of performing its intended 36 function. The statements of consideration (SOC) (Ref. 4) clarify that 37 licensees are not required to monitor under paragraph (a)(1) of the rule 38 if they have demonstrated that preventive maintenance has been effective or 39 if an SSC has inherently high reliability and availability as discussed below.
40 41 1.
Demonstrated Effective Maintenance: As stated in the SOC, under the 42 terms of paragraph (a)(2), preventive maintenance must be demonstrated to 43 be effective in controlling the performance or condition of an SSC so that 44 the SSC remains capable of performing its intended function.
In order to 4S assure that preventive maintenance is effective, some evaluation or 46 monitoring process needs to be established under paragraph (a)(2).
47 48 (a)
Performance Criteria: NUMARC 93-01 (Ref. 2) introduced the use of 49 performance criteria as a method of deinonstrating satisfactory 50 performance or condition under paragraph (a)(2) of the rule. Where the 51 performance or condition is not adequately controlled, the SSC would 52 generally be dispositioned to paragraph (a)(1).
Section 9.3.2 of 53 NUMARC 93-01 recommends that performance criteria should be 54 availability, reliability, or condition.
It also recommends that 55 specific performance criteria be established for all risk-significant j
Issue Date: XX/XX/XX XXXXX l
h
D RAFT
~
'(specific guidance 03.02.b.' cont.)
i 1
SSCs and for non-risk-significant SSCs that are in a standby (not 2
normally operating) mode.
Plant-level performance criteria would be 3
established for all remaining non-risk-significant, normally operating 4
SSCs.
PerformancecriterjawouldnotberequiredforSSCsdetermined 5
to be inherently reliable or for those SSCs that contribute little or 6
nothing to safety function and that could be allowed to run to failure 7
(i.e., perform corrective maintenance rather than preventite 8
maintenance).
9 10 (b) Maintenance-Preventable (Functional) Failure: Section 9.4.5 of 11 NUMARC 93-01 (Ref. 2) recommends the use of the term " maintenance 12 preventable functional failures (MPFFs)" rather than " maintenance 13 preventable failures (MPFs)" as described in the SOC, in order to 14 differentiate between failures that cause an SSC to be incapable of 15 performing its intended function and failures that do not affect an 16 SSC's function. There are many possible failures of some SSCs that 17 would not affect the intended safety function of the system.
18 19 (c) Dispositionina from paraaraoh (a)(2) to paraaraoh (a)(1): The S0C 20 (Ref. 4) states that it is expected that where one or more maintenance 21 preventable failures (or MPFFs) occur on SSCs treated under paragraph 22 (a)(2), the effectiveness of preventive maintenance is no longer 23 demonstrated. As a result, the SSC would be required to be treated 24 under the requirements of paragraph (a)(1) until such time as a 25 performance history is established to demonstrate that performance or 26 condition are once again effectively controlled by an established 27 preventive maintenance regimen. Section 9.4.4 of NUMARC 93-01 (REF. 2) 28 provides additional guidance on determining when dispositioning SSCs 29 from paragraph (a)(2) to paragraph (a)(1) would be required. This 30 would generally be required if a performance criterion were not met or 31 if a repetitive MPFF occurs. The inspector should note that an SSC 3
32 could continue to be treated under paragraph (a)(2) after experiencing 33 a single MPFF if the root cause evaluation determined the cause of the 34 failure and if the corrective action that was taken prevented 35 recurrence. However if a second, repetitive, MPFF occurred, then the 36 SSCs would have to be dispositioned to paragraph (a)(1). Once an SSC's 37 preventive maintenance has been demonstrated effective again, it would 38 be acceptable to return to treating the SSC under paragraph (a)(2).
39 Section 9.4.3 of NUMARC 93-01 (Ref. 2) provides guidance for 40 dispositioning SSCs from paragraph (a)(1) to paragraph (a)(2).
41 i
3 42 The statements of consideration (Ref. 4) describe the purpose of (a)(2) 43 of the maintenance rule as to provide an alternate approach for those SSCs 44 where it is not necessary to establish the monitoring regime required by 45 paragraph (a)(1). This provision might be used where an SSC, without 46 preventive maintenance, has inherent reliability and availability (e.g.,
47 electrical cabling) or where the preventive maintenance necessary to achieve 48 high reliability does not itself contribute significantly to unavailability 49 (e.g., moisture drainage from an air system accumulai.or). NUMARC 93-01, i
50 sections 9.3.3 and 10.2 (Ref.2), describe an inherently reliable SSC as one 51 that, without preventive maintenance, has high reliability (e.g., jet shields, 52 raceways).
i XXXXX y Issue Date: XX/XX/XX
DRAFT (specific guidance 03.02.b. cont.)
1 The inspector should verify that the licensee has established and 2
implemented some monitoring or assessment process for determining if the 3
preventive maintenance program is effectively maintaining the reliability 4
of those SSCs (except for inherently reliable SSCs described below) that 5
are maintained exclusively under paragraph (a)(2) of the maintenance rule.
6 The inspector should review the maintenance history for a sample of SSCs 7
maintained under paragraph (a)(2) to verify that the monitoring or 8
assessment process ensures that acceptable performance or condition of the 9
SSCs is maintained and, where that performance or condition degrades to an 10 unacceptable level or experiences a second maintenance preventable failure, 11 the SSC is treated under paragraph (a)(1) until such time as the 12 performance or condition improves to an acceptable level. The inspector 13 should select a sample of SSCs that experienced maintenance preventible 14 functional failures and raview the licensee's actions to determine if they 15 were dispositioned properly.
16 17 2.
Preventive Maintenance Not Reouired: As indicated in the S0C (Ref. 4),
18 the purpose of paragraph (a)(2) of the rule is to provide an alternate 19 approach for those SSCs where it is not necessary to establish the 20 monitoring regimen required by paragraph (a)(1).
This includes those SSCs 21 that are adequately controlled by preventive maintenance (described above) 22 and those SSCs that are inherently reliable without maintenance (described 23 below), or those SSCs that are of low risk significance (described below):
24 25 (a)
Inherently Reliable: This provision might be used where an SSC, 26 without preventive maintenance, has inherent reliability and 27 availability (e.g., electrical cabling) or where the preventive 28 maintenance necessary to achieve high reliability does not itself 29 contribute significantly to unavailability (e.g., moisture drainage 30 from an air system accumulator).
It is expected that many structures, 31 such as cable raceways, water storage tanks, and buildings, could be 32 considered inherently reliable. However, it should be noted that such 33 activities as inspections, surveys, and walkdowns could be considered 34 maintenance activities and, therefore, most SSCs would be subject to 35 some maintenance. Therefore, the concept of identifying inherently 36 reliable SSCs as those that require no maintenance may be of limited 37 usefulness.
Licensees should document their reasons for concluding 38 that certain SSCs are inherently reliable.
39 40 The inspector should review the documentation for a :: ample of SSCs that 41 have been determined to be inherently reliable, verify that the 42 licensee's determination appears reasonable, and that the SSC's 43 condition or performance is acceptable without maintenance.
44 45 (b) Low Risk Sionificance: Methods for determining risk (or safety) 45 significance are described in NUMARC 93-01, section 9.0 (Ref. 2). As 47 described in NUMARC 93-01, section 9.3.3 (Ref. 2), SSCs that contribute 48 little or nothing to system safety function could be allowed to run to 49 failure (i.e., perform corrective maintenance rather than preventive 50 maintenance). To accomplish this, the licensee should establish 51 appropriate criteria for determining if SSCs have low risk significance 52 and should use these criteria to identify SSCs that could be allowed to 53 run to failure.
Licensees should document these criteria and their 54 reasons for deciding that individual SSCs could be allowed to run to 55 failure.
Qg{
Issue Date: XX/XX/XX XXXXX
J Rl~$ r p m r.m m I!" E (specific guidance 03.02.b. cont.)
1 The inspector should select a sample of these SSCs and evaluate them to i
2 verify that the licensee has followed its own criteria for determining 3
low risk significance and that these evaluations are reasonable.
4 5
6 03.02.c.
Periodic Evaluations. 50.65 (a)(3). The licensee is required by 7
paragraph (a)(3) of the maintenance rule to perform the following periodic 8
assessments and evaluations:
9 10 1.
Refuelina Cycle Evaluation: The rule requires that licensees evaluate 11 performance and condition monitoring activities and associated goals and 12 preventive maintenance activities at least every refueling cycle, provided 13 the interval between evaluations does not exceed 24 months. The S0C 14 (Ref.a) states that these activities are to be evaluated in light of SSC 15 reliabilities and availabilities as well as the following:
16 17 (a) Goals and Monitorina:
For SSCs under paragraph (a)(1),
18 adjustments are to be made to goals, monitoring, or preventive 19 maintenance activities when equipment or performance has not met 20 established goals. Conversely, the licensee may, at any time, 21 eliminate the monitoring activities initiated in response to 22 problematic equipment performance or industry experience once the root 23 cause of the problem has been corrected and the adequacy of the 24 equipment performance has been confirmed.
25 26 On the basis of a review of records and discussions with responsible 27 personnel, the inspector should verify that the licensee has reviewed 28 goals, monitoring, and preventive maintenance activities and made 29 adjustments, where necessary.
30 31 (b) Preventive Maintenance:
For SSCs under paragraph (a)(2),
32 adjustment of preventive maintenance activities may be warranted where 33 SSC availability is judged to be unacceptable.
SSCs treated under 34 paragraph (a)(2) which experience repetitive maintenance-preventable 35 functional failures (MPFFs), become subject to the requirements of 36 paragraph (a)(1) or, where this is not feasible, may require other 37 remedial action, such as modification or replacement.
38 39 On the basis of a review of records and discussions with responsible 40 personnel, the inspector should verify that the licensee has adjusted 41 preventive maintenance activities where necessary and dispositioned 42 SSCs that experienced repetitive HPFFs to the requirements of paragraph 43 (a)(1).
44 45 (c) Operatina Experience: The maintenance rule also requires that the 46 evaluations shall take into account, where practical, industrywide 47 operating experience. Sources of industrywide operating experience 48 include, but are not limited to, NRC bulletins and information notices, 49 the INP0 NPRDS, vendor technical information letters (TILs), and vendor
)
50 service information letters (SILs).
51 52 The inspector should verify that the licensee has established and 53 implemented a documented method or process for considering industry 54 operating experience when performing evaluations.
55 Qg{
XXXXX Issue Date: XX/XX/XX
DRAFT
. (specific guidance 03.02.c. cont.)
1 2.
Balancina Unavailability and Reliapiljty: The maintenance rule 2
requires that licensees make adjustments where necessary to ensure that the i
3 objective of preventing failures of SSCs through maintenance is 4
appropriately balanced against the objective of minimizing unavailability 5
of SSCs due to monitoring or preventive maintenance activities. The intent 6
of this requirement is to ensure that monitoring or preventive maintenance 7
activities do not result in excessive unavailability that would negate any 8
improvement in reliability achieved as a result of the monitoring or 9
maintenance activity.
This process can be qualitative, but it should be 10 documented. Additional guidance is provided in section 12.2.4 of NUMARC 11 93-01 (Ref. 2).
12 13 The inspector should ask licensees to explain their processes and to 14 provide examples of evaluations that resulted in adjustments to achieve 15 this balance. The inspector should verify that the licensee has 16 implemented a method or process for evaluating the improvements in 17 reliability and balancing them against the unavailability that results from 18 maintenance.
19 20 3.
Assessment of Eauioment Out of Service:
In performing monitoring and 21 preventive maintenance activities, an assessment of the total plant 22 equipment that is out of service should be taken into account by the 23 licensee to determine the overall effect on the performance of safety 24 functions. This assessment is to be performed on an ongoing basis, not 25 just during the periodic assessment performed at the end of every refueling 26 cycle. As stated in the S0C (Ref. 4), assessing the cumulative impact of 27 out-of-service equipment on the performance of safety functions is intended 28 to ensure that the plant is not placed in risk-significant configurations.
29 These assessments do not necessarily require that a quantitative assessment 30 of probabilistic risk be performed.
However the PRA or IPE may provide 31 useful information on risk significance of various SSCs. The level of 32 sophistication with which such assessments are performed is expected to 33 vary, according to the assessments performed. These assessments may range 34 anywhere from simple deterministic judgments to the use of an on-line 35 living PRA.
It is expected that, over time, assessments of this type will 36 be refined as the technology improves and experience is gained.
In order 37 to accomplish these assessments licensees must keep track of the status (in 38 or out of service) of plant equipment. This status may be kept as a manual 39 list or on a database but must be easily accessible and kept up to date.
40 In order to be useful and accessible the information should be kept in one 41 location and not scattered among several documents (shift logs, status 42 boards, tag out status boards) in various locations. Additional guidance 43 is provided in section 11.0 of NUMARC 93-01 (Ref.2 ).
44 45 The inspector should verify, based on a review of licensee records and 46 discussions with appropriate personnel, that the licensee has established 47 and implemented an ongoing, documented process for assessing the overall 48 effect on the performance of safety functions before SSCs are taken out of 49 service for monitoring or preventive maintenance. The inspector should 50 verify that the licensee maintains a list of all SSCs within the scope of 51 the maintenance rule and that the licensee updates this list to indicate 52 when SSCs are in or out of service. The inspector should select a sample 53 of SSCs from the licensee's list of SSCs that have been taken out of 54 service and review the adequacy of the evaluations made by the licensee 55 before taking the SSCs out of service. The inspector should also verify i
Issue Date: XX/XX/XX XXXXX
(specific guidance 03.02.c. cont.)
I that the licensee reviews the results of this process during the periodic 2
assessment performed each refueling cycle.
3 4
03.02.d.
Scope of the Rule. 50.65(b). The scope of SSCs that are required to 5
be included within the rule is defined in 10 CFR 50.65(b). Section 8.0 of 6
NUMARC 93-01 (Ref. 2) provides additional guidance on methods for selecting 7
SSCs to be included in the scope of the maintenance rule.
In order to verify 8
that the licensee has correctly identified and documented SSCs at its facility 9
the inspector should perform the following reviews.
10 11 1.
Safety-Related SSCs per 50.65(b)(1):
Identifying safety-related SSCs 12 should be uncomplicated since all licensees should have a well-defined list 13 of safety-related SSCs in their final safety analysis report, (FSARs),
14 Q-lists or master equipment lists (MELs).
15 16 The inspector should independently review the FSAR, Q-list, or MEL to 17 select a sample of SSCs and then verify that the licensee has included 18 these safety-related SSCs within the scope of the maintenance rule.
19 20 2.
Non-Safety-Related SSCs That are Relied Voon to Mitioate Accidents or 21 Transients per 50.65(b)(2)(1): The FSAR describes non-safety-related SSCs 22 needed to mitigate accidents and transients.
Examples of non-safety-23 related SSCs that are used in the FSAR analysis to mitigate accidents 24 include: the condensate storage tank (supply to auxiliary feedwater), the 25 fire-suppression system, and the boric acid transfer system used for l
26 emergency boration and makeup water to the refueling water storage tank.
27 28 The inspector should independently review the plant safety analysis report 29 and attempt to identify a sample of non-safety-related SSCs relied upon to 30 mitigate accidents or transients.
If it is not feasible to select an 31 independent sample in this manner, the inspector should perform a review of 32 non-safety related SSCs that were identified by the licensee as necessary 33 to mitigate accidents and transients. This sample may include a very small 34 number of SSCs. The inspector should review the licensees determinations 35 and verify that they appear to be reasonable.
36 37 3.
Non-Safety-Related SSCs That Are Used in Emeroency Operatino Procedures 38 (EOPs) cer 50.65(b)(2)(1):
Paragraph (b)(2)(1) of the maintenance rule 39 states that all SSCs in E0Ps are required to be included within the scope 40 of the rule. However, many utilities have included more SSCs in their E0Ps i
41 than are required by the Emergency Procedure Guidelines.
Some of these 42 SSCs were included because they could possibly assist in the event of an 43 emergency, not because they are relied upon in the licensee's accident 44 analysis to protect other equipment from being damaged or contaminated.
45 Subsequently, the NRC staff endorsed the guidance contained in section 46 8.2.1.3 of NUMARC 93-01 (Ref. 2) which allows the exclusion from the rule 47 of those non-safety-related SSCs that are not considered important because 48 they do not add significant value to the mitigation function of an E0P by 49 providing a significant fraction of the total functional ability reqJired 50 to mitigate core damage or radioactive release. Some examples of SS s that 51 might be excluded on this basis are instrumentation that provides :edundant 52 local information and does not provide a control function, fire-protection 53 system capacity capable of supplying only a small fraction of what is 54 required to mitigate the accident, and portable emergency equipment that is 55 available from offsite sources and is not under utility control.
XXXXX Issue Date: XX/XX/XX L
DRAFT (specific guidance 03.02.d. cont.)
l 1
Conversely, if a fire-protection system provides a large fraction of what 2
is required to mitigate the accident, it should be under the scope of the 3
rule. The inspector should keep these exceptions in mind when reviewing 4
the scope of SSCs included in the rule.
5 6
The inspector should independently review the E0Ps to identify a sample of 7
non-safety-related SSCs and verify that they are included within the scope 8
of the rule or were excluded based on the criteria described above. The 9
inspector should select a sample of SSCs from the E0Ps that were excluded 10 from the rule and verify that the licensee's documented reasons for i
11 excluding the SSC from the rule appear to be reasonable.
12 13 4.
Non-Safety-Related SSCs Whose Failure Could Prevent Safety-Related SSCs 14 From Fulfillina Their Intended Function as per 50.65(b)(2)(ii): To 15 identify failure modes of non-safety-related SSCs that will directly affect 16 safety-related functions, the licensee should investigate the systems and 17 their interdependencies. A utility should rely on actual plant-specific 18 and industrywide operating experience', prior engineering evaluations such
)
19 as PRA, IPE, environmental qualification (EQ), and 10 CFR Part 50 (Appendix 20 R) analyses.
Industrywide operating experience should be used to the 21 extent practical to preclude unacceptable performance experienced at a 22 similar plant from being repeated.
Examples of such non-safety-related 23 SSCs could include instrument air system that opens containment isolation 24 valves for purge and vent, a fire damper in the standby gas treatment 25 system whose failure would impair air flow, or a condensate storage water 1
26 tank that is a source of water for ECCS.
However, it is not intended that 27 licensees attempt to determine hypothetical failures that could result from 28 system interdependencies that have not previously been experienced or 29 analyzed. NUMARC 93-01, section 8.2.1.4 (Ref. 2) provides additional 30 guidance. See paragraph 03.02.d step 6 below for exceptions.
31 32 The inspector should review records of failu es of non-safety-related 33 systems and attempt to identify a sample of 3Cs that could have prevented 34 a safety-related SSC from fulfilling its intended function. The inspector i
35 should verify that the licensee has included these SSCs within the scope of 36 the maintenance rule.
If it is not feasible to select an independent 37 sample in this manner, the inspector should perform a review of the non-38 safety related SSCs that were identified by the licensee as likely to 39 prevent safety related SSCs from fulfilling their intended function. The 40 inspector should review the licensees determinations and verify that they 41 appear to be reasonable.
42 43 5.
Non-Safety-Related SSCs Whose Failure Could Cause a Scram or Actuation 44 of a safety System as per 50.65(b)(2)(iii):
Licensees are required to 45 identify, on the basis of utility-specific and industrywide operating
'Industrywide operating experience includes information from NRC, 46 47 industry, and vendor sources that is generally available to the nuclear 48 industry. Sources of this type of information could include: NRC bulletins, 49 information notices, generic letters,10 CFR Part 21 reports; the INP0 NPRDS 50 system, vendor service, and technical information letters and reports.
It is 51 intended that licensees will obtain this operating experience information from 52 existing programs; it is not intended that licensees will establish new 53 programs to satisfy the needs of the maintenance rule.
Issue Date: XX/XX/XX 13 -
XXXXX
DRAFT (specific guidance 03.02.d. cont.)
I experience, those non-safety-related SSCs whose failure could cause a 2
reactor scram or safety system actuation. The licensee should consider 3
other engineering evaluations, such as PRA, IPE, environmental 4
qualification (EQ), and 10 CFR Part 50 (Appendix R) analyses. The licensee 5
should also consider industrywide operating experience and any event that 6
has occurred at a similarly configured plant. However, the licensee is not 7
required to determine hypothetical failures that could result from system 8
interdependencies that have not previously been experienced or analyzed.
9 Examples of transient initiators from the FSAR include turbine trips, loss 10 of feedwater, and loss of instrument air.
Examples of non-safety-related 11 SSCs whose failure could cause a plant trip are the turbine generator, non-12 ESF buses that power reactor coolant pumps, and rod control system failure 13 that allows multiple rods to drop into the core. One example of a non-14 safety-related system whose failure could cause a safety system actuation 15 is a radiation monitor which could isolate control room ventilation.
i 16 NUMARC 93-01, section 8.2.1.5 (Ref. 2), provides additional guidance.
17 18 The inspector should review licensee event reports or other available 19 operating history information to identify SSCs that have actually caused a 20 scram or safety system actuation and should verify that those SSCs had been 21 included in the licensee's maintenance program.
22 23 6.
SSCs Outside the Scope of the Maintenance Rule: Unless they meet the 24 criteria described above, the following categories of SSCs are generally 25 outside the scope of the maintenance rule: fire protection systems; seismic i
26 class II SSCs installed in proximity to seismic class I SSCs; security 27 systems; and, emergency facilities described in the emergency plan.
28 Further guidance is provided in section 8.2.1.6 of NUMARC 93-01 (Ref. 2).
29 30 The inspector should not expect that these SSCs would be included within 31 the scope of the maintenance rule because maintenance requirements already 32 exist for these categories of SSCs.
33 34 7.
Switchyard Activities: The regulatory guide (Ref.1) states that the 35 scope of monitoring efforts under the maintenance rule, as defined in 10 36 CFR 50.65(b), encompasses those SSCs that directly and significantly affect 37 plant operations, regardless of which organization actually performs the 38 maintenance activities. Maintenance activities performed by plant 39 maintenance personnel, as well as by corporate maintenance or contractor 40 personnel, come under the scope of the rule. Since maintenance activities 41 that are performed in the switchyard can directly affect plant operations, 42 electrical distribution equipment out to the first intertie with the off-43 site distribution system (i.e., equipment in the switchyard) should be 44 considered for inclusion under the scope of the maintenance rule.
Plant 45 managers should be aware of, and should have the ability to control, these 46 activities even if the switchyard is not onsite.
47 48 The inspector should verify that the appropriate SSCs in the switchyard are 49 included within the scope of the maintenance rule.
50 51 8.
Safety Systems with Non-safety Functions:
Examples provided in section 52 8.2.1 of NUMARC 93-01 (Ref. 2) illustrate that some safety-related systems 53 may perform safety-related as well as non-safety-related functions.
In
$4 such cases, the components that perform only a non-safety-related function 55 may not necessarily come under the scope of the rule.
For example, the XXXXX f Issue Date: XX/XX/XX
(specific guidance 03.02.d. cont.)
1 non-safety-related function of an ECCS could be to fill the safety i
2 injection accumulators.
3 4
The inspector should not expect that these SSCs with non-safety-related 5
functions necessarily come within the scope of the maintenance rule.
6 7
9.
Documentation. The licensee's process for reviewing and selecting SSCs 8
shall be documented. The licensee shall also develop a list of all those l
9 SSCs selected for inclusion within the scope of the rule. This list could 10 take the form of either a manual list or an electronic database.
In either 11 case, licensees must have a process to periodically revise the list as 12 modifications or other changes are made to the plant that result in SSCs 13 being added or deleted from the scope of the rule.
NUMARC 93-01, section 14 13.2 (Ref. 2) provides additional guidance on documenting the SSC selection 15 process.
16 17 The inspector should verify that the licensee has established adequate 18 documentation which includes a listing of all SSCs that are within the 19 scope of the maintenance rule and made provisions for updating the list.
20 21 Summary for 03.02.d.. Scope of the Rule 50.65(b). steos 1 throuah 9: If the 22 inspector identifies one or more significant examples, or several minor 23 examples, of failures to identify SSCs required to be within the scope of the 24 rule, the inspector should examine the licensee' process and procedures to 25 determine why they were not included.
26 27 03.03.
Effectiveness of Emeraency Diesel Generator Maintenance Activities.
28 The inspection requirements and guidance given in other sections of this 29 inspection procedure apply to all SSCs within the scope of the maintenance 30 rule, including the emergency diesel generators.
In addition, the following 31 requirements derived from Regulatory Guide 1.160 apply to emergency diesel 32 generators only.
33 34 03.03.a.
Early Implementation for Emeraency Diesel Generators:
In order to 35 remove certain EDG requirements from the technical specifications and still 36 satisfy certain commitments made in response to the station blackout rule (10 37 CFR 50.63), licensees may elect to implement the requirements of the 38 maintenance rule for the emergency diesel generators earlier than the 39 effective date of the maintenance rule, July 10, 1996.
If the licensee has 40 made the decision to remove the SB0 commitments from the technical 41 specifications, then the maintenance of the emergency diesel generators would 42 be subject to inspection under the requirements of the maintenance rule before 43 July 10, 1996.
44 45 03.03.b. Tarcet Reliability Values as Goals or Performance Criteria: The 46 station blackout rule (10 CFR 50.63) requires each licensee to perform plant-47 specific coping analyses to ensure that a plant can withstand a total loss of 48 ac power for a specified duration and to determine appropriate actions to 49 mitigate the effects of a total loss of ac power. Most licensees endorsed the 50 program embodied in NUMARC 87-00 (ref. 3) and subsequently docketed 51 commitments to maintain a target EDG reliability value of either 0.95 or 52 0.975. These target values could be used as the basis for spali or as 53 performance criteria for EDG reliability under the maintenance rule (10 CFR 54 50.65). As part of their plant-specific coping analyses, licensees were 55 allowed to use plant-specific data concerning unavailability due to Issue Date: XX/XX/XX XXXXX
DRAFT (specific guidance 03.03.b. cont.)
1 maintenance. This unavailability due to maintenance, assumed in a plant-2 specific individual plant examination (IPE) analysis, could also be used as 3
the basis for coals or performance criteria for EDG reliability under the 4
maintenance rule.
5 6
The inspector should verify that the licensee has either (1) incorporated 7
these commitments into its maintenance program as goals or performance 8
criteria or (2) established an alternate method of meeting licensee 9
commitments to the station blackout rule and the requirements of the 10 maintenance rule.
11 12 03.03.c.
Balancina Unavailability and Reliability:
Paragraph (a maintenance rule requires that adjustments be made where necessary)(3) of the 13 to ensure 14 that the objective of preventing failures of SSCs through maintenance is 15 appropriately balanced against the objective of minimizing unavailability of 16 SSCs due to monitoring or preventive maintenance. Therefore, both plant-17 specific EDG reliability and plant-specific EDG availability should be 18 monitored as goals under paragraph (a)(1) or should be established as j
19 performance criteria under the plant's preventive maintenance program under i
20 paragraph (a)(2), to satisfy the objectives of paragraph (a)(3). The 21 regulatory guide endorses the example in NUMARC 93-01, section 12.2.4 (Ref.
22 2), which refers to optimizing EDG reliability and availability.
23 24 The inspector should verify that the licensee is monitoring both plant-25 specific EDG reliability and plant-specific EDG availability as goals under 26 paragraph (a)(1) or performance criteria under paragraph (a)(2), or that the 27 licensee has established an alternate method of meeting its commitments to the 28 station blackout rule and paragraph (a)(3) of the maintenance rule for 29 emergency diesel generators.
30 31 03.03.d.
Dispositionina From Paraaraoh (a)(2) to Paraoraoh (a)(1):
Licensees 32 who decide to establish performance criteria under paragraph (a)(2) of the 33 maintenance rule would establish performance criteria for EDG reliability and 34 EDG unavailability. The performance criteria for reliability could be, for 35 example, no maintenance-preventable failures, or a maximum of one maintenance-36 preventable failure if it is followed by appropriate root-cause determination, 37 corrective action, and subsequent EDG performance monitoring to assure the 38 problem was resolved.
Likewise, the performance criteria for unavailability 39 could be set as a specific maximum number of unavailable hours, on a rotating 40 1-year basis.
If either of the performance criteria is exceeded, then the 41 licensee would be required to set goals and to monitor under paragraph (a)(1) 42 of the maintenance rule. The regulatory guide (Ref.1) endorses the example 43 in NUMARC 93-01, section 12.2.4 (Ref. 2), which describes an acceptable method 44 to establish EDG performance criteria and/or goals and subsequently monitor 45 EDG performance.
46 47 The inspector should review the performance criteria established by the 48 licensee and the performance history of the EDG to verify that the performance 49 criteria were not exceeded, or, if they were exceeded, that goals were set and 50 monitoring was performed in accordance with paragraph (a)(1) of the 51 maintenance rule.
52 53 03.03.e.
Implementina the Station Blackout Rule: The EDG reliability 54 performance criteria or goals selected for implementing the intent of the 55 station blackout rule (10 CFR 50.63) for coping with station blackout could be 1
XXXXX Issue Date: XX/XX/XX
s
+-
u (specific guidance 03.03.e. cont.)
I monitored through the use of the triggers and monitoring methods described in 2
Appendix D of NUMARC 87-00 (except for triggers and testing for " problem 3
diesels" as described in section D.2.4.4) (Ref. 3). An acceptable 4
unavailability goal could be to have fewer hours of unavailability (on a 5
rotating 1-year basis) than the number of hours established as acceptable by 6
the licensee.
7 8
The inspector should review the EDG reliability and availability commitments 9
made by the licensee in response to the station blackout rule and verify that 10 these commitments have been addressed by the licensee's implementation of the 11 maintenance rule or that the licensee has established an alternate method of 12 meeting its commitments to the station blackout rule and the requirements of 13 the maintenance rule.
14 i
15 5
16 XXXXX-04 RESOURCE ESTIMATE 17 18 19 XXXXX-05 REFERENCES 20 21 1.
U.S. Nuclear Regulatory Commission, Regulatory Guide 1.160," Monitoring the 22 Effectiveness of Maintenance at Nuclear Power Plants," June 1993 23 24 2.
Nuclear Management and Resources Council, NUMARC 93-01, " Industry 25 Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power 26 P1 ants," May 1993 27 28 3.
Nuclear Management and Resources Council, NUMARC 87-00, Revision 1, 29
" Guidelines and Technical Bases for NUMARC Initiatives Addressing Station 30 Blackout at Light Water Reactors, August '1991."
31 32 4.
U.S. Nuclear Regulatory Commission, " Statements of Consideration (SOC) for 33 Monitoring the Effectiveness of Maintenance," Federal Reaister, Vol. 56, No.
34 132, Wednesday July 10, 1991, pages 31306 to 31324.
35 36 37 38 END 5
39 The resource estimate provides an estimate of the number of onsite 40 inspection hours required to complete this inspection.
This estimate is for 41 broad resource planning and is not intended as a quota or standard for judging 42 inspector or regional performance. The actual inspections performed at a 43 specific plant may require substantially more or less time, depending on 44 circumstances.
DRAFT Issue Date: XX/XX/XX xxxxx
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