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Erclosure 1 SAFETY EVALUATION REPORT FOR-GENERIC LETTER 83-28, ITEM 1.1 - POST-TRIP REVIEW (PROGRAM DESCRIPTION AND PROCEDURE)
. PILGRIM STATION DOCKET NOS.: 50-293 1.
INTROD'JCTION On February 25, 1983, both of the scram circuit breakers at Unit 1 of the Salem Nuclear Power Plant (SNFP) failed to open upon an automatic reactor trip signal from the reactor protection system. This incident occurred during the plant start-up and the reactor was tripped manually by the operator about 30 seconds after the initiation of the automatic trip signal.
The failure of the circuit creakers has been determined to be related to the sticking of the under voltage trip attachment.
On Februdry 22, 1983, during start-up of SNPP, Unit 1, an automatic trip signal occurred as the result of steam generator low-low level.
In this case, the reactor was tripped manually by the operator almost coincidentally with the automatic trip.
Following these incidents, or, February 28, 1983, the NRC Executive Director for Operations (ED0) directed the staff to investigate and report on the generic implications of these occurrences. The results of the stafs inquiry into these incidents are reported in NUREG-1000, " Generic Implications of ATWS Events at the Salem Nuclear Power Plant." As a result of this investigation, the Comunission requested (by Generic Letter 53-28 dated July 8,1983) all licensees of operating reactors,. applicants for an operating license, and holders of construction permits to respond to certain generic concerns. These concerns are categorized into four areas:
(1)
Post-TripReview,(2) Equipment Classification and Vendor Interface, (3)
Post-Maintenance Testing, and (4) Reactor Trip System Reliability Improvements.
The first action item, Post-Trip Review, consists of Action Item 1.2,
" Program Description and Procedure," and Action Item 1.2, " Data ard Information Capability." This safety evaluation report (SER) adcresses Action Item 1.1 only.
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II.
REVIEW GUIDELINES 1
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.The following review guidelines were developed after initial evaluation of various utility responses to Item 1.1 of Generic Letter 83-28, and incorporate the best features of these submittals. As.such, these review guidelines in effect represent a " good practices" approach to post-trip review. We have reviewed the licensee's response to Item 1.1 against these guidelines:
A.
The licensee or applicant should have systematic safety assessment procedures established that will ensure that the following restart criteria are met before restart is authorized.
l The post-trip review team has detenmined the root cause and sequence of events resulting in the plant trip.
Near term corrective actions have been taken to remedy the cause of.
the trip.
l The post-trip review team has performed an analysis and determined that the major safety systems responded to the event within specified limits of the primary system parameters.
The post-trip review has not resulted in the discovery of a potential safety concern (e.g., the root cause of the event occurs with a frequency significantly larger than expected).
If any of the above restart criteria are not met, then an independent assessment of the event is performed by the Plant Operations Review Committee (PORC), or another designated group with similar authority and experience.
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The responsibilities and authorities of the personnel w*o will perform the review and aralysis should be well defined.
The post-trip review team leader should be a membe of plant i
management at the shift supervisor level or above and should hold or should have held an SR0 license for the plant. The team leader should be charged with overall responsibility for <!irecting the i
post-trip review, including data gathering and data assessment and he/she should have the necessary authority to obtain all personnel I
and data needed for the post-trip review.
A second person on the review team should be an STA or should hold a relevant engineering degree with special transiv.t analysis training.
The team leader and the STA (Engineer) should be responsible to concur on a decision / recommendation to restart the plant. A nonconcurrence from either of these persons shoule be sufficient to I
prevent restart until the trip has been reviewed by the PORC or equivalent organization, j
C.
The licensee or applicant should indicate that the plant response to the trip event will be evaluated and a determination made as to whether the plant response was within acceptable limits.
The evaltation should include:
A verification of the proper operation of plant systems and equipment by comparison of the pertinent data obtained during the post-trip review to the applicable data provided in the FSAR.
An analysis of the sequence of events to verify tre proper I
functioning of safety related and other important ecuipment. Where possible, comparisons with previous similar events should be made.
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The licensee or applicant should have procedures to ensure that all physical evidence necessary for an independent assessment is preserved.
E.
Each licensee or applicant should provide in its submittal, copies of the plant procedures which contain the information required in Items A through D.
As a minimum, these should include the following:
The criteria for determining the acceptability of restart The qualifications, responsibilities and authorities of key personnel involved in the post-trip review process The methods and criteria for determining whether the plant variables and system responses were within the limits as described in the FSAR The criteria for determining tre need for an independent review.
III.
EVALUATION AND CONCLUSION By letters dated November 7,1983, and August 13, 1985, the licensee of Pilgrim Station provided information regarding its Post-Trip Review Program and Procedures.
We have evaluated the licensee's program and procedures against the review guidelines described in Section II.
A brief description of the licensee's response and the staff's evaluation of the response agains:
each of the review guidelines is provided below:
A.
The licensee has established the criteria for determining the acceptability of restart.
Based on our review, we find that the licensee's criteria conform to the guidelines described in Section II.A and, therefore, are acceptable.
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B..
The qualifications, responsibilities and authorities of the personnel who will perfom the review and analysis have been clearly described, l
1 We have reviewed the licensee's chain of comand for responsibility for post-trip review and evaluation, and find it acceptable.
C.
The licensee has described the methods and criteria for comparing the event information with known or expected plant behavior. Based on our i
review, we find them to' be acceptable.
D.
The licensee has established the criteria for determining the need for an independent assessment conducted by the Operation Review Comittee.
-In addition, the licensee has established procedures to ensure that all physical evidence necessary for an independent assessment is preserved.
We find these actions conform with the guidelines described in Sections II.A and D.
E.
The licensee has provided a systematic safety assessment program to assess unscheduled reactor trips. We have reviewed this program and find it acceptable.
Based on our review, we conclude that the licensee's Post-Trip Review Program and frocedures for Pilgrim Station are acceptable.
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SALP EVALUATION PILGEIM STATION DOCKET NO.: 50-293 GENERIC LETTER 83-28, ITEM 1.1, POST-TRIP REVIEW A.
Functional Areas: Licensing A:tivities - Generic Letter 83-28, Item 1.1, Post-Trip Review 1.
Management involvement in assuring quality Based on our review of the licensee's response.to Generic Letter 83-28, we find that the licensee's management was involved in assuring that the issues were resolved.
Rating: Category 2 2.
Approach to resolution of technical issues from a safety standpoint Rating:
N/A' 3.
Responsive to NRC initiatives Based on our review, we find that the licensee is responsive to NRC initiatives.
Rating: Category 2 4.
' Staffing Rating:
N/A 5.
Reporting and analysis of reportable events Rating: N/A 6.
Training and qualification effectiveness Rating: N/A 7.
Overall Rating for Licensing Activity Functional Areas: Category 2
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