ML13308A226
| ML13308A226 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/09/1983 |
| From: | Rood H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8302250147 | |
| Download: ML13308A226 (7) | |
Text
FEB 9 1983 Docket Nos.:
50-361 and 50-362 LICENSEES:
Southern California Edison Company (SCE)
San Diego Gas and Electric Company City of Anaheim, California City of Riverside, California FACILITY:
San Onofre Nuclear Generating Station, Units 2 and 3
SUBJECT:
SUMMARY
OF MEETING TO AUDIT THE CORE PROTECTION CALCULATOR (CPC) TEST PROGRAM AND OBSERVED THE STATUS OF THE INADEQUATE CORE COOLING (ICC).INSTRUMENTATION On December 7 and 8, 1982, members of the NRC staff and a consultant visited the San Onofre site to audit the CPC startup test program and to observe the status of the ICC instrumentation at San Onofre Unit 3. A summary of the meeting is given below.
CPC Audit The audit was initiated with a meeting to discuss the various review items which had been identified to SCE in advance. At the meeting the staff was informed that Combustion Engineering (CE) and SCE personnel, in perparing for the audit, had discovered a non-conservative error in the values of the power multiplier addressable constants used to define instrument uncertainties.
The error results in a non-conservative power cglibration uncertainty value of 7.5 percent compared to a required value of 10 percent. The latter value was transmitted to SCE from CE by letter dated August 20, 1981.
The letter was said to be lost and the modification was not implemented. This resulted in a Technical Specification violation and will be reported in more detail in an LER regarding the event.
A review of the August 20 letter and discussion of the procedures regarding modifications of this nature revealed that the procedures are inadequate.
CE/SCE indicated their intent to review and revise their QA procedures for modifications of this nature. The revised procedures are to be submitted for staff review.
SCE/CE provided prepared written responses to the audit items which had been identified by the staff. Their preparation was through and served to expedite the audit. A summary of our findings follow:
(a) Operator training, including two four hour courses in the details of CPC operation, was described. Operators are permitted to enter only four addressable constants without engineering approval.
These are:
8302250147 820209 PDR ADOCK 05000361 P
PDR OFFICEO....................
SURNAMEfr................................
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL R ECO RD COPY USGPO: 1981-335-960
-2 Pt ID Symbol 60 FC1 flow calibratibn constant 61 FC2 flow calibration constant 64 TPC thermal power calibration constant 65 KCAL neutron flux power calibration constant A notebook of pertinent operator procedures was provided to the staff.
(b) Constants affecting the core power distribution calculations are maintained at values which always result in conservative outputs with respect to predicted values during power escalation. The following examples were given for radial peaking factor (RPF):
Power Level Predicted Maximum Value of RPF Measured Value 20%
1.38 50%
1.44*
1.4135 100%
1.40 (incomplete)
Combustion Engineering agreed to provide curves of predicted outputs for power dependent variables to illustrate that CPC outputs are conservative for intermediate power levels between measurements during power escalation.
These will be provided informally for staff review unless questions result from that review.
It was unclear from the documents available at the meeting whether CPC constants would be verified above the 50 percent power level (80 percent and 100 percent) during start-up testing. SCE agreed that further infor=D-'Y'n mation will be provided to the staff and procedures will be justified if they do not include high power verification of constants.
(c) SCE provided a prepared description of their CPC flow calibration procedures and results. A description of the resolution of an apparent problem involving reactor coolant pump (RCR) shaft speed inputs, which was the subject of a license condition, was also 6 ro provided. The staff was satisfied with these responses.
- Maximum CPC value during power escalation.
OFFICE I..........
SURNAME...
DATE
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
-4 Corrective actions being taken to avoid recurrence of this type of error involves additional training of software design personnel at CE in the application of QA standards to the generation and indepen dent review of software documentation. In addition, a new document detailing the standards to be followed in the generation and review of software documentation is being prepared. CE agreed to submit this document for staff review as a supplement to software change procedures for CPC systems still under review.
CPC Observation A periodic test disc was inserted for a test of the siftware on one calaulator. A listing of the addressable constant data base was ob tained. Spot checks of addressable constant values in other calculators were performed at the console. A listing report on data base values in the CPCs add the CEAC calculators was obtained from the plant computer.
No software errors were evident.
It was noted that with the plant at about 50 percent power, the CPC indicated power level was about 2.5 percent less than the COLSS indi cated power level.
The CPC indicated power was in close agreement with the secondary calorimetric power. When questioned, available SCE personnel could not explain the descrepancy and did not know which power indication would be used to ascertain when the plant is operating at the license power limit. A written response to these questions was promised.
Staff Recommendations Resulting from CPC Audit and Observation (1) Quality Assurance and Software Change Procedures for CPC/CEAC software should be revised to correct deficienceis identified during this audit and should be submitted for staff review and approval prior to approval of CPC systems for plants still in the licensing process.
(2) The software error which precludes application of the CEAC penalty factor to LPD calculations in accordance with approved software design specifications is known to exist in the ANO-2, Waterford, and San Onofre 2 and 3 software systems. CPC operation with this e
error has been justified by CE on the basis that DNB trips would occur occur prior to any LPD trips that might be initiated when applying the CEAC penalty factor. The staff has not reviewed this justifi cation in detail, but believes that the nature of the problem precludes complete assurance that this conclusion is true. Even if the conclusion is valid, we believe that the errorsdigrades the protection provided by the CPCs by effectively eliminating one software trip path to the protection circutt. While the safety concern does not appear serious enough to warrant plant shutdowns for correction, we believe that the software should be corrected as soon as practical without imparing operation.
OFFICE..............................................................................................................
SURNAME DATE NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 198 1-335-960
-5 Observation of Status of Installation ICC Instrumentation During the meeting the staff observed the status of the ICC instrumentation and found that installation progress appeared to be on schedule.
Harry Rood, Project Manager Licensing Branch No. 3 Division of Licensing cc:
See next page DL:LB#3 3
OFFICE ton SURNAME 2/gy/83 I27_______________7_________________
DATE..
DATE s.............
NRC FORM 318 (10-80) NRCM 0240 OFFICIAL R ECORD Cop PY SGPO: 1981-335i-960
San Onofre Mr. Robert Dietch Vice President Southern California Edison Company 2244 Walnut Grove Avenue P. 0. Box 800 Rosemead, California 91770 Mr. Gary D. Cotton Mr. Louis Bernath San Diego Gas & Electric Company 101 Ash Street San Diego, California 92112 cc:
Charles R. Kocher, Esq.
Mr. Mark Medford James A. Beoletto, Esq.
Southern California Edison Company Southern California Edison Company 2244 Walnut Grove Avenue 2244 Walnut Grove Avenue P. 0. Box 800 P. 0. Box 800 Rosemead, California 91770 Rosemead, California 91770 Mr. Henery Pet rs Orrick, Herrington & Sutcliffe San Diego Gas Electric Company ATTN:
David R. Pigott, Esq.
P. 0. Box 1831 600 Montgomery Street San Diego, California 92112 San Francisco, California 94111 Ms. Lyn Harris Hicks Mr. George Caravalho Advocate for GUARD City Manager 3908 Calle Ariana City of San Clemente San Clemente, California 92672 100 Avenido Presidio San Clemente, California 92672 Richard J. Wharton, Esq.
University of San Diego School of Law Alan R. Watts, Esq.
Environmental Law Clinic Rourke & Woodruff San Diego, California 92110 Suite 1020 1055 North Main Street Phyllis M. Gallagher, Esq.
Santa Ana, California 92701 Suite 222 1695 West Crescent Avenue Lawrence Q. Garcia, Esq..
Anaheim, California 92701 California Public Utilities Commission 5066 State Building Mr. A. S. Carstens San Francisco, California 94102 2071 Caminito Circulo Norte Mt. La Jolla, California 92037 Mr. V. C. Hall Combustion Engineering, Inc.
Charles E. McClung, Jr., Esq.
1000 Prospect Hill Road Attorney at Law Windsor, Connecticut 06095 24012 Calle de la Plata/Suite 330 Laguna Hills, California 92653 Mr. S. McClusky Bechtel Power Corporation Resident Inspector, San Onofre/NPS P. 0. Box 60860, Terminal Annex do U.S. Nuclear Regulatory Commission Los Angeles, California 90060 P. 0. Box 4329 San Clemente, California 92672 Mr. Dennis F. Kirsch U.S. Nuclear Regulatory Comm. - Reg. V Regional Administrator-Region V/RC 1450 Maria Lane, Suite 210 1450 Maria Lane/Suite 210 Walnut Creek, California 94596 Walnut Creek, California 94596
SAN ONOFRE
-2 Mr. C. B. Brinkman Combustion Engineering, Inc.
4853 Cordell Avenue Bethesda,- Maryland 20814
MEETING
SUMMARY
FEB 9 1983 Document Control (50-361/362)
NRC PDR
- 1. PDR NSIC TERA LB#3 Reading J. Lee G. Knighton Project Manager H. Rood Attorney, OELD E. L. Jordon Regional Administrator, Region V
J. M. Taylor PARTICIPANTS (NRC):
HRood LPhillips CBerlinger