HomeMy WebLinkAbout851161.tiff E P"aE°1/2y UNITED STATES
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W � t_ NUCLEAR REGULATORY COMMISSION
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JUN 061986
In Reply Refer To:
Docket: 50-267 vn'(D aey ;..,,
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Public Service Company of Colorado 119 ,
ATTN: 0. R. Lee, Vice President (�
Electric Production $REELEY, coLck__
P. 0. Box 840
Denver, Colorado 80201
Dear Mr. Lee:
We have reviewed the sections of your November 4, 1983, letter in response to
Generic Letter 83-28 regarding action item 1.1, "Program Description and
Procedures." The results of our review are contained in the enclosed safety
evaluation report.
Based on our review, we have concluded that the Fort St. Vrain Post-Trip
Review Program and Procedures are acceptable. We, therefore, consider
item 1.1 to be completed.
If you have any questions on this subject, please contact the NRC Project
Manager.
Sincerely,
E. H. Johnson, Chief
Reactor Project Branch 1
Enclosure:
Safety Evaluation Report
cc:
Mr. D. W. Warembourg, Manager
Nuclear Engineering Division
Public Service Company of Colorado
P. 0. Box 840
Denver, Colorado 80201
Mr. David Alberstein, 14/159A
GA Technologies, Inc.
P. 0. Box 85608
San Diego, California 92138
(cont. on page 2)
851161
V-,.1 ...+a
Public Service Company of Colorado -2-
Kelley, Stansfield & O'Donnell
Public Service Company Building
550 15th Street, Room 900
Denver, Colorado 80202
Chairman, Board of County Comm.
of Weld County, Colorado
Greeley, Colorado 80631
Regional Representative
Radiation Programs
Environmental Protection Agency
1860 Lincoln Street
Denver, Colorado 80203
Mr. H. L. Brey, Manager
Nuclear Licensing/Fuels Div.
Public Service Company of Colorado
P. 0. Box 840
Denver, Colorado 80201
J. W. Gahm, Manager, Nuclear
Production Division
Fort St. Vrain Nuclear Station
16805 WCR 194
Platteville, Colorado 80651
L. Singleton, Manager, Quality
Assurance Division
(same address)
Colorado Radiation Control Program Director
Enclosure 1
SAFETY EVALUATION REPORT FOR
GENERIC LETTER 83-28 ITEM 1.1 - POST-TRIP REVIEW
PROGRAM DESCRIPTION AND PROCEDURE)
FORT S I. YRAIN NUCLEAR GENERATING STATION, UNIT 1
DOCKET NO. : 50-t67
I. INTRODUCTION
On February 25, 1983, both of the scram circuit breakers at Unit 1 of the
Salem Nuclear Power Plant failed to open upon an automatic reactor trip
signal from the reactor protection system. This incident occurred during the
plant start-up and the rfactor was tripped manually by the operator about 30
seconds after the initiation of the automatic trip signal . The failure of
the circuit breakers has been determined to be related to the sticking of the
under voltage trip attachment. Prior to this incident, on February 22, 1983,
at Unit 1 of the Salem Nuclear Power Plant, an automatic trip signal was
generated based on steam generator low-low level during plant start-up. In
this case, the reactor was tripped manually by the operator almost
coincidentally with the automatic trip. Following these incidents, on
February 28, 1983, the NRC Executive Director for Operations (EDO), directed
the staff to investigate and report on the generic implications of these
occurrences at Unit 1 of the Salem Nuclear Power Plant. The results of the
staff's inquiry into the generic implications of the Salem unit incidents are
reported in NUREG-1000, "Generic Implications of ATWS Events at the Salem
Nuclear Power Plant." As a result of this investigation, the Commission
(NRC) requested (by Generic Letter 83-28 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-Trip Review, (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 1.1,
"Program Description and Procedure" and Action Item 1.2, "Data and
Information Capability." This safety evaluation report (SER) addresses
Action Item 1.1 only.
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II . REVIEW GUIDELINES
The following review guidelines were developed after initial evaluation of
the 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.
o The post-trip review team has determined the root cause and
sequence of events resulting in the plant trip.
o Near term corrective actions have been taken to remedy the cause
of the trip.
o 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.
o 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) .
o 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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B. The responsibilities and authorities of the personnel who will perform
the review and analysis should be well defined.
o The post-trip review team leader should be a member of plant
management at the shift supervisor level or above and should hold
or should have held an SRO license on the plant. The team leader
should be charged with overall responsibility for directing the
post-trip review, including data gathering and data assessment and
he/she should have the necessary authority to obtain all personnel
and data needed for the post-trip review.
o A second person on the review team should be an STA or should hold
a relevant engineering degree with special transient analysis
training.
o 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 should be sufficient to
prevent restart until the trip has been reviewed by the PORC or
equivalent organization.
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 evaluation should
include:
o 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.
o An analysis of the sequence of events to verify the proper
functioning of safety related and other important equipment. Where
possible, comparisons with previous similar events should be made.
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D. 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:
o The criteria for determining the acceptability of• restart
o The qualifications, responsibilities and authorities of key
personnel involved in the post-trip review process
o The methods and criteria for determining whether the plant
variables and system responses were within the limits as described
in the FSAR
o The criteria for determining the need for an independent review.
III. EVALUATION AND CONCLUSION
By letter dated November 4, 1983, the licensee of Fort St. Vrain Nuclear
Generating Station provided information regarding its Post-Trip Review
Program and Procedures. We have evaluated the licensee's program and
procedures against the review guidelines developed as described in
Section II. A brief description of the licensee's response and the staff's
evaluation of the response against each of the review guidelines is provided
below:
A. The licensee's criteria for determining the acceptability of restart
include: a verification that the reactor protection system and the
engineered safety features and systems which are important to reactor
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safety have performed as required; verification of the cause of the trip
and the adequacy of subsequent corrective action; and conduct of an
analysis to evaluate the plant transient behavior. We find that the
licensee's criteria for determining the acceptability of restart are
acceptable.
B. The qualifications, responsibilities and authorities of the personnel
who will perform the review and analysis have been clearly described.
The licensee indicated that the Station Manager, who bases his decision
on the above cited restart acceptability criteria, shall have the final
authority to grant or deny authorization of plant restart. We have
reviewed the licensee's chain of command for responsibilities for
post-trip review and evaluation, and find them acceptable.
C. The licensee has described the methods and criteria for comparing the
event information with known or expected plant behavior. Based on our
review, we find them to be acceptable.
D. With regard to the criteria for determining the need for independent
assessment of an event, the licensee has indicated that if the cause of
the trip cannot be positively determined, or if the plant response
demonstrated an abnormal behavior that has not been corrected or results
in Technical Specification start-up constraints, an independent
assessment of the event will be performed by the Transient Review
Committee. In addition, the licensee has established procedures to
ensure that all physical evidence necessary for an independent
assessment is preserved. We find that these actions to be taken by the
licensee conform to the guidelines as described in the above Sections
II.A. and D.
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E. The licensee has provided for our review a systematic safety assessment
program to assess unscheduled reactor trips. Based on our review, we
find that this program is acceptable.
Based on our review, we conclude that the licensee's Post-Trip Review Program
and Procedures for Fort St. Vrain Nuclear Generating Station rare acceptable.
Date: May 7, 1985
Principal Contributor:
D. Shum -
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