ML17308A165
| ML17308A165 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 12/17/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17308A164 | List: |
| References | |
| NUDOCS 8512260049 | |
| Download: ML17308A165 (4) | |
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~O sgy*gsds UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION GENERIC LETTER 83-28 INTRODUCTION 3.2.2 4.1 and 4.5.1
. In February 1983, the Salem Nuclear Power Station experienced two failures of the reactor-trip system upon the receipt of trip signals.
These failures were attributed to Westinghouse
- Type,DB-50 reactor-trip system (RTS) circuit breakers.
The failures'at Salem on February 22 and 25, 1983, were believed to have been caused by a binding action within the undervoltage trip attach'ment (UVTA) located inside the breaker cubicle.
Due to problems with the circuit breakers at Salem,and other plants, NRC issued Generic Letter 83-28, Required Actions Based on Generic Implications of Salem Anticipated Transient Without Scram (ATWS) Events, dated July 8, 1983.
This letter required the licensees.to respond on 4nedfate-term actions to ensure reliability of the RTS.
Actions to be performed,fncluded development of programs to provide for post-trip review, classiffcatfon of equipment, vendor fnterface, post-maintenance
- testing, and RTS reliability improvements.
The Generic Letter stated that for Actions. 3.1. 1, 3. 1.2, 3.2. 1, 3.2.2, 4.1 and 4.5.1, NRC Regional Offices would perform a 'post-implementation review and issue Safety Evaluations (SE).
This report is the staff's SE for St. Lucie Nos.
1 and 2 and includes the results of the staff's review of the licensee's submittal to Generic Letter 83-28 (GL 83-28).
An inspection was conducted at the St. Lucfe facility during July 8-12,
- 1985, to rev'few the licensee's current program, planned program improvements, and implementation of preSent proceduI'es associated with post-trfp review, equipment classification, vendor interface, post-maintenance
- testing, and reactor-trip system reliability.
The details of"the inspection ffndfngs are discussed fn Region II's 'Inspection Report No. 335, 389/85-19.
This Safety Evaluation addresses the NRC staff's positions delineated fn GL 83-28 for Action Items 3. 1.1, 3.1.2, 3.2. 1, 3.2.2, 4.1 and 4.5.1.
The requirements of the above action items as described fn GL 83-28 are paraphrased below:
3.1 POST-MAINTENANCE TESTING (REACTOR TRIP SYSTEM COMPONENTS) 2.
Licensees and applicants shall submit the results of their review of test and maintenance procedures
'and Technical Specifications to assure that post-maintenance operability testing of safety-related components in the RTS fs r'equired to be conducted and that the testfng d'emonstrates that the equipment is capable of peiforming fts safety functions before being returned to service.
1 Licensees and applicants shall submit the results of their check of vendor and engineering recommendations to ensure that any appropriate test guidance fs included fn the test and maintenance P
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3.2 POST MAINTENANCE TESTING ALL OTHER SAFETY-RELATED COMPONENTS)
The following actions are applicable to post-maintenance testing:
1.
Licensees and applicants shall submit a report documenting the extending of test and maintenance procedures and Technfcal Specifications review to assure that post-maintenance operability testing of all safety-related equipment is required to be conducted and that the testing demonstrates that the equipment is capable of performing its safety functions before being returned to service.
2.
Licensees and app1icants shall submit the results of their check of vendor arid engineering recomaendations to ensure that any appropriate test gufdance fs included in the test and maintenance p
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4.1 REACTOR TRIP SYSTEM RELIABILITY (VENDOR-RELATED MODIFICATIONS)
All vendor-recommended reactor trip breaker modifications shall be reviewed to verify that either:
(1) each modification has, in fact, been implemented; or (2) a written evaluation of the technical reasons for not implementing a modification exists.
For example, the modifications recommended by Westinghouse in NCD-Elec-18 for the DB-50 breakers and a March 31, 1983, letter for the DS-416 breakers shall be implemented or a justification for not implementing shall be made available.
Modifications not previously made shall be incorporated or a written 'evaluation shall be provided.
4.5 REACTOR TRIP SYSTEM RELIABILITY (SYSTEM FUNCTIONAL TESTING)
On-line functional testing of the reactor trip system, including independent testing of the diverse trip features, shall be performed on all plants.
The diverse trip features to be tested include the breaker undervoltage and shunt trip features on Westinghouse, Babcock and Wilcox (BKW) and Combustfon Engineerfng (CE) plants; the circuitry used for power interruption with the silicon-controlled rectffiers on BOW plants; and the scram pilot valve and backup-scram valves (including all initiating circuitry) on General Electrfc (GE) plants.
EVALUATION By letter dated November 8, 1983, Florida Power and Light Company, the licensee of St. Lucie Plant, Unit Nos.
1 and 2 provided information regarding their compliance with Sections
- 3. 1, 3.2, 4.1 and 4.5 of GL 83-28.
The staff has evaluated the licensee's response against the NRC posftions for completeness and adequacy.
The staff has concluded that the licensee's response to item
- 3. 1.2, was incomplete and additional informatfon is needed in order to complete its evaluation.
- However, items 3.1.1, 3.2,1, 3.2.2, 4.1, and 4.5.1 are acceptable.
For item 3.1.2, additional information has been requested.
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( The results of the staff's evaluations for each item are as follows:
a ~
b.
c ~
d.
Item 3. 1.1 - Test and Maintenance Procedure Review (Reactor Trip System Components)
The licensee's response to this item is acceptable and meets the intent of GL 83-28.
The licensee states in its response that it has reviewed its test and maintenance procedures and Technical Specifications and has determined that current maintenance procedures provide for retest and functional operation of equipment after maintenance is performed.-
The licensee also stated that Technical Speci'fication 6.8. 1 requires implementation of these procedures.
Item 3.1.2, Check of Vendor and Engineering Recommendations for Testing and Maintenance (Reactor Trip System Components)
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.'he licensee's response to this item is considered incomplete and additional information is needed to determine acceptability.
The licensee states in its response that all identified recomnendations concerning the reactor trip switchgear have been included in appropriate test and maintenance procedures.
The licensee also states that the Availability Data Program and the CE Info-bulletins provide information-and recomnendations on CE NSSS equipment and that future changes to test guidance would show up in this program and would be dispositioned by means of the Operating Experience Feedback Program.
However, the licensee does not definitely state whether a review was made of test and maintenance procedures for other safety-related components in the RTS to verify that appropriate and current vendor and engineering information was included in the procedures.
It is, concluded from the licensee's response that'only new and revised vendor information will be reviewed and evaluated for incorpor'ation into the procedures.
The response does not address the adequacy of current (in use) procedures which were developed from older vendor and engineering recommendations.
The licensee needs to review its current test and maintenance procedures for safety-related components in the RTS (other than the reactor trip switchgear) and verify that appropriate, test guidance is included in the test and'aintenance procedures or the Technical Specifications and submit a statement confirming that this action has been implemented.
Item 3.2.1, Review of Test and Maintenance Procedures and Technical Specifications (All Other Safety-Related Components)
The licensee's response to this item is acceptable and meets the intent of GL 83-28.
The licensee states in its response that test and maintenance procedures have been reviewed and it has determined that post-maintenance operability testing of all safety-related equipment is required to be conducted and that the testing demonstrates that the equipment is capable of performing its safety functions before being returned to service.
The response also states that Technical Specification 6.8.1 requires that these test and maintenance procedures be implemented.
Item 3;2.2, Check of Vendor and Engineering Recommendations for Testing and Maintenance (All Other Safety-Related Components)
e.
The licensee's response to this item is acceptable and meets the intent of GL 83-28.
The licensee states in its response that all identified engineering and vendor recommendations have been included in the test and maintenance procedures.
The response also states that for CE supplied equipment, these recommendations are provided in Info-bulletins as part of the CE Availability Data Program.
The licensee states that, as participants in the INPO See-In
- Program, a continuing program exists to receive and review stgnificant events occurring throughout the nuclear industry and important vendor information items are entered in the FPSL'perating Experience Feedback Program.
This program provides additional assurance that test and maintenance items which have 'caused problems at other plants will be reviewed for applicability to St. Lucie 1 and 2 and dispositioned.
Item 4. 1, Reactor Trip System Reliability (Vendor-Related Modifications)
The licensee's response to this action item is acceptable and meets the intent of GL 83-28.
The licensee states in its response that all identified reactor trip circuit breaker modifications have been implemented at St. Lucie 1 and 2.
Although not addressed in response to this item, the licensee inferred in response to items 3.1, 3.2 and 4.2 that all future vendor recomnendations would be evaluated for incorporation into its program.
The staff interprets this to include Service Information Letters from GE and cur'rent vendor technical and maintenance manuals.
An example is the latest GE recommendation to replace existing trip shaft bearings with bearings lubricated with Mobil 28 lubricant.
Item 4.5. 1 Reactor Trip System Reliability (System Functional Testing)
The licensee's response to this item is acceptable and meets. the intent of GL 83-28.
The licensee confirmed in its response that on-line functional testing of the diverse trip features, including the breaker undervoltage and shunt trip features, are performed at least monthly in accordance with Operating Procedure
- 1400059, Reactor Protection System
- Periodic Logic Matrix Test.
Also, the channel functional test of the reactor protection system logic and reactor trip breakers is required monthly by Technical Specifications 4.3.1.1.1 (St. Lucie 1) and 4.3.1.1 (St. Lucie 2) and Table 4.3-1.
CONCLUSION Based on the above, the staff concludes that the licensee's response to item 3.1.2 fs incomplete and additional information is needed to complete the evaluation.
- However, items 3.1.1, 3.2.1, 3.2.2, 4.1 and 4.5.1 are acceptable and meet the intent of GL 83-28.
Acceptable response to the above noted deficiency is required before the staff can complete its review.
Principal Contributors:
T. Conlon N. Merriweather L. Foster D. Sells Date:
December 17, 1985