ML20237D870
| ML20237D870 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/21/1987 |
| From: | Long W Office of Nuclear Reactor Regulation |
| To: | Bennett W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| TAC-66370, NUDOCS 8712240248 | |
| Download: ML20237D870 (3) | |
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[o UNITED STATES
'g NUCLEAR REGULATORY COMMISSION n
h WASHINGTON, D. C. 20555
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December 21, 1987 Docket 50-298/ TAC 66370 MEMORANDUM FOR:
W.R. Bennett, Sr. Resident Inspector NRC Region IV P.O. Box 218 Brownville, NE 68321 FROM:
W.0. Long, Project Manager Project Directorate-IV Division of Reactor Projects - III, IV, V and Special Projects
SUBJECT:
COOPER NUCLEAR STATION DIESEL GENERATOR SURVEILLANCE TEST REQUIREMENTS Cooper Technical Specification 4.9.A.2.a requires a monthly test of the diesel generators during which the time to start and attain rated voltage and frequency is to be " logged".
Technical Specification 4.9. A.2.b requires an 18 month test in which the time to start and assume the emergency load sequence is to be
" logged".
Neither Technical Specification specifies test acceptance criteria for these items to be logged.
The plant surveillance procedures associated with these Technical Specifications also lack acceptance criteria.
In Inspection Report 50-298/86-36, Unresolved Item 86-36-01 questions whether a USAR 10 second timing requirement for the diesels to start and attain rated voltage and frequency is a monthly or once per cycle surveillance requirement.
The item also noted that the 18 month surveillance test measures the interval from diesel start to breaker closing, rather than to rated voltage and frequency, allowing an additional 3 seconds for breaker closing.
To clarify requirements, a request for information was sent to the licensee (Enclosure 1).
The licensee's response (Enclosure 2) states that the start-time measurement is an eighteen-month test and that surveillance procedure 6.3.4.3 will be revised to include test acceptance criteria.
The licensee's response also clarifies that 10 seconds is the required time for start to attainment of rated voltage and frequency, and that, based on the LOCA/LOSP analysis assumptions, 16 seconds from start to breaker closing is acceptable.
The licensee also committed to revise the USAR for consistency with the LCCA/LOSP analysis assumptions.
l It is our position that the licensee's response satisfactorily resolves the j
issue.
We note that Regulatory Guide 1.108 and NUREG-0123 (Standard Technical Specifications) indicate that the start-time to rated voltage and frequency I
should be a monthly test.
However, based on past performance (Enclosure 3 test 8712240240 071221 PDR ADOCK 05000290 0
s-data),-which indicates that there is no particular safety concern relative to Cooper's diesel start-time performance, an eighteen month interval is acceptable.
It is NRR's recommendation that 86-36-01 be closed.
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Willam 0. Long, Project Manager Project Directorate-IV Division of Reactor Projects - III, IV, V and Special Projects
Enclosures:
As stated DISTRIBUTION Docket File NRC PDR Local PDR PD4 Reading DR4A/J. Collins J. Calvo P. Noonan W. Long 0GC-Bethesda E. Jordan J. Partlow G. Hollar G. Madsen W. McNeill ACRS (10)
PD4 Plant File PD4/L 1)
PD4/PM g PD4/D //I' I
PNoona WLong JCalvo lO40l/87 lqr/p /87
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ENCLOSURE 1
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et OCT 151987 Docket No. 50-298 L
Mr. George A. Trevers, Division L.
Manager - Nucitar Support Nebraska Public Power. District l
Post Office Box 499 L
Columbus, Nebraska 68601
Dear Mr. Trevors:
SUBJECT:
DIESEL GENERT0R SURVEILLANCE TESTING (TAC N0. 66370)
Re:
Cooper Nuclear Station In Inspection Report 50-298/86-36, the staff questions the frequency for surveillance testing of CNS's diesel generators for time to start and attain rated voltage and frequency. The staff has reviewed CNS Surveillance Procedures 6.3.12.6 Diesel Generator Annual. Inspection, 6.3.12.1 Diesel Generator Operability Test (Monthly Surveillance), and 6.3.4.3 Sequential Loading of Emergency Diesel Our review indicates that the CNS diesel generator surveillance Generators.
program may be inadequate with. respect to ensuring ECCS capability in event of a design basis LOCA with loss'of offsite power.
Surveillance Procedure 6.3.4.3 does not appear to contain a pass / fail acceptance criterion for time to start and attain rated voltage and frequency.
It only tests the ECCS pumps timing delays at referenced to the time at which the DG breaker closes on the bus. We therefore request your response to the following (1) Is 6.3.4.3 intended to test the time interval between the questions.
LOCA/LOSP signal and breaker closing (assuming breaker closing occurs at rated voltage.and frequency)? If not, which test is? (2) Is the 13 second period indicated in Attachment 4 of the test procedure intended to be an acceptance criterion? If ;o, what is the basis for the 13 second criterion as opposed to 10 seconds which would be consistent with the USAR7 Your response is requested within 45 days.
If ycu have any questions please contact me at 301-492-4754 The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearnace is not required under P.L.
1 96-511.
Sincerely, William 0. Long, Project Manager i
I Project Directorate - IV m -7 q
Division of Reactor Projects - III, MM l^
3 r7 - i bTAf# Cd }U ct /J g
IV, V and Special Projects cc:
See next page DISTRIBUTION Docket File NRC PDR Local PCR PD4 Reading 7
W. Long )
F. Schroeder J. Calvo' P. Noonan ACRS (10 OGC-Bethesda E. Jordan J. Partlow PD4 Plant File E. Plettner J. Jaudon.
R. Bennett LTR NAME; DIESEL TESTING COOPER PD4/L g PD4/PM a' PD4/Dfjj<
t PNoonanI WLong:sr JCalvo 10/16/87 10/d/87 10/g/87
Mr. George A. Trevors Nebraska Public Power District Cooper Nuclear Station cc:
Mr, G. D.. Watson, General Counsel Nebraska Public Power District P. O. Box 499 Columbus, Nebraska' 68601 Cooper Nuclear Station 1
ATTN: Mr. Guy R. Horn, Division Manager of Nuclear Operations
.P. O. Box 98 Brownville, Nebraska 68321 Director Nebraska Department of Environmental Control P. O. Box 94877 State House. Station Lincoln, Nebraska 68509-4877 l
Mr.. William S4ebert, Commissioner Nemaha County Board of Commissioners Nemaha' County Courthouse Auburn, Nebraska 68305 Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 218 Brownville, Nebraska 68321 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011
-Mr. Harold Borchart, Director Division of Radiological Health Department of Health 301 Centennial Mall, South P. O. Box 95007 l
Lincoln, Nebraska 68509
s f "C%h UNITE D ST ATEs e
NUCLE AR REGULATORY COMMISSION
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W ASHINGTON, D. C. 20555 i
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OCT 151987 Eccket No. 50-298 Mr. George A. Trevers, Division Manager - Nuclear Support hebraska Public Power District Post Office Box 499 Columbus, Nebraska 68601
Dear Mr. Trevers:
SUBJECT:
DIESEL GENERATOR (DG) SURVEILLANCE TESTING (TAC N0. 66370)
Re:
Cooper Nuclear. Station In Inspection Report 50-298/86-36, the staff questions the frequency for surveillance testing of CNS's diesel generators for time to start and attain rated voltage and frequency.
The staff has reviewed CNS Surveillance Procedures 6.3.12.6 Diesel Generator Annual Inspection, 6.3.12.1 Diesel Generator Operability Test (Monthly Surveillance), and 6.3.4.3 Sequential Loading of Emergency Diesel Generators. Our review indicates that the CNS diesel generator surveillance program may be inadequate with respect to ensuring ECCS capability in event of a design basis LOCA with loss of offsite power.
Surveillance Procedure 6.3.4.3 does not appear to contain a pass / fail acceptance criterion for time to start and attain' rated voltage and frequency.
It cnly tests the ECCS pumps timing delays as referenced to the time at which the DG breaker closes on the bus.
We therefore request your response to the following questions.
(1) Is 6.3.4.3 intended to test the time interval between the LOCA/LOSP signal and breaker closing (assuming breaker closing occurs at rated voltage and frequency)? If rect, which test is? (2) Is the 13 second period irdicated in Attachment 4 of the test procedure intended to be an acceptance criterion? If so, what is the basis for the 13 second cri erion as opposed to 10 seconds which would be consistent with the USAR?
Your response is requested within 45 days.
If you have any questions please contact me at 301-492-4754.
The reporting and/or recordkeeping requirements ccntained in this letter affect fewer than ten respondents; therefore, OMB clearr. ace is not required under P.L.96-511.
Sincerely, L Avp William O. Long, Project Manager Project Directorate - IV N M. b i )-]c 92 Division of Reactor Projects - III,
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IV, Y and Special Projects cc:
See next page l
L____ _ __________ _
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'I Mr. George A. Trevors Nebraska Public Power District Cooper Nuclear Station l
CC:
Mr. G. D. Watson, General Counsel l
Nebraska Public Power District F. O. Box 499 Columbus, Nebraska 68601 Cooper Nuclear Station A7N: Mr.. Guy R.. Horn, Division Manager of Nuclear Operations P. O. Box 98
.Brownville, Nebraska 68321 l
-Director Nebraska Department of Environmental Control P. O. Box 94877 State' House' Station Lincoln, Nebraska 68509-4877 Mr. William Siebert, Commissioner Nemaha County Board of Commissioners Nemaha County Courthouse Auburn, Nebraska 68305 Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 218 Brownville, Nebraska 68321 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000
, Arlington, Texas 76011 Mr. Harold Borchart, Director, Division of Radiological Health Department of Health 301 Centennial Mall, South P. O. Box 95007 Lincoln, Nebraska 68509
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ENCLOSURE 2 a
GENERAL OFFICE Nebraska Public Power District
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NLS8700633 December.4, 1987 l
l U.S. Nuclear Regulatory Commission l
Attention: Document Control Desk
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j l
Washington, DC 20555 Gentlemen l
Subject:
Diesel Generator (DG) Surveillance Testing l
~
Reference:
Letter.from W. 0. Long to G. A. Trevors, dated October 15, 1987, same subject In accordance with the request for further information regarding our diesel generator surveillance testing contained within the referenced letter, the following response is provided.
For clarity in presentation, the specific information requests are noted and are followed by the District's response.
Requested Information
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1.
Is 6.3.4.3 intended to test the time interval between the LOCA/LOSP signal and breaker closing (assuming breaker closing occurs at rated voltage and frequency)? If not, which test is?
Response
Yes, Surveillance Procedure 6.3.4.3 provides verification of the time interval between LOCA/ LOOP initiation signal for diesel generator standing and DG output breaker closing.
Even though the acceptance criterion was not explicitly stated, the District has reviewed the last ten years of test data and confirmed that the DG timing met the requirements. inherent in the CNS LOCA Analysis, NEDO 24045.
Procedure 6.3.4.3 will be revised to include the specific acceptance criterion, as further discussed in response to Question 2.
Requested Information 2.
Is the 13 second period indicated in Attachment 4 of the test procedure j
intended to be an acceptance criterion?
If so, what is the basis for the 13 second criterion as opposed to 10 seconds, which would be consistent with the USAR?
Response
The 13 second period indicated in Attachment 4,
is incorrect in that the initiating event at t=o should not be low reactor water icvel but rather LOCA initiation.
This would then be consistent with USAR Tabic VIII-5-2.
Ibweve r, the District believes some misunderstanding of the i
significance of Table VIII-5-2 exists.
This table represents a typical bYh D
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J
" S. Nuslear Regulatory Commission.
-Page,2-December 4,/1987 i
sequential loading of a diesel generator.
The ten (10) second start time is the DG design start time (i.e.
time from etart signal received to ~ time required to reach rated voltage and frequency) as described in USAR Chapter VIII, Section 5.3.2.
The applicable safety requirements can be determined from the CNS Loss.
of Coolant Analysis, General' Electric NED0-24045.
The District and General 4
Electric have reviewed this document and its assumptions and determined that a diesel generator start-up time (from receipt of diesel generator initiation signal to output breaker closure) of 16 seconds is adequate
.for Cooper's configuration. assuming worst case LOCA scenario.
To resolve this issue, the District will 1)' review USAR Table -VIII-5-2
~)
revise Surveillance against NEDO-24045 and its input assumptions and 2
Procedure 6.3.4.3 prior to the next required 18 month test.
Although u.
.these document clarifications are appropriate, the District's review has nevertheless concluded that the CNS Diesel Generator Surveillance Program has been conservative with respect to ensuring ECCS capability in the unlikely event of a design basis LOCA with ' concurrent loss of offsite power.
If you have ' any questions regarding this response, please contact Mr. G6y Horn at Cooper Nuclear Station.
Sincerely, revors Division Manager Nuclear Support
/jw cc:
U.S. Nuclear Regulatory Commission Region IV Office Arlington, TX NRC Resident Inspector Cooper Nuclear Station bei NRC Distribution l
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