ML20042C338
| ML20042C338 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/25/1982 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20042C335 | List: |
| References | |
| NUDOCS 8203310244 | |
| Download: ML20042C338 (4) | |
Text
f i
\\
$SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, califomia 95813; (916) 452 3211 March 25,1982 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTENTION JOHN F STOLZ CHIEF OPERATING REACTORS BRANCH 4 U S NUCLEAR REGULATORY COMMISSION WASHINGTON D C 20555 DOCKET 50-312 RANCHO SECO NUCLEAR GENERATING STATION UNIT NO 1 HPI N0ZZLE USAGE The Sacramento. Municipal Utility District has received a copy of the Atomic Safety and Licensing Appeal Board's Memorandum and Order dated March 8,1982.
This order requests the NRC Staff to answer several questions by March 31, 1982. We wish to offer the following information for your assistance in pre-paring a reply to the Appeal Board's questions.
During the hearings following the Three-Mile-Island accident, there was some oral testimony centered around the contention that the change in setpoints for PORV and reactor trip and the control grade reactor trips which had been installed following the accident would lead to excessive use of the safety systems at Rancho Seco.
It was brought out in this testimony that the high pressure injection nozzles had originally been designed for forty cycles and that over thirty had already been utilized.
It is true that the original design basis for the plant included forty cycles of high pressure injection initiation plus forty cycles of test initiation of the system.
Following the hearing, operating procedures were changed and no additional thermal cycles have occurred to the high pressure injection nozzles. We concur with Mr. Padovan's January 5, 1982 affidavit that "there is sufficient existing margin to the design thermal cycle limits on the HPI nozzles to permit continued plant operation over the near term."
Also following the hearing, the District requested an analysis by B&W to provide additional cycles for the nozzles.
Staff questions have recently arisen con-cerning this analysis, but it should be made clear to the Appeal Board that the questions only relate to the additional seventy cycles and not the original eighty.
8203310244 820326 DRADOCK05000g Ah MG 6 F OR8 99MELafto n n o
JOHN F STOLZ March 25,1982 We feel it is significant that the original analyses showed a nozzle usage of only 0.44 and therefore the number of allowable cycles could be doubled without consideration of or resort to any new analysis. We feel that the original issue regarding excessive use of safety systems, brought up during the hearing, is no longer an item of concern. We also feel that the NRC staff review of our analysis providing additional cycles for the high pressure injection nozzles, should be conducted as a normal review by the staff under 10 CFR 50.59 since no immediate concern exists.
Recent indications of cracking in the make-up nozzles at the Crystal River and Oconee units were not created by excessive use of the high pressure injection system.
Instead it is felt that these abnormalities have been created by unusually low flow through the make-up nozzle during normal plant operation at these plants. At the present time it is felt that this low flow condition has resulted in excessive thermal stresses to these nozzles during normal plant operation. No indications have yet been discovered at nozzles used solely for high pressure injection. As pointed out in our March 9 letter to Darrell G. Eisenhut, we feel that the make-up flows, and nozzle design preclude this problem from occurring at Rancho Seco. As verification, we plan an inspection of our nozzles by April 9,1982, as discussed in our March 19, 1982 letter to Mr. Eisenhut.
In any case, the problem is not related to excessive use of the high pressure injection system, but rather to unique normal operation characteristics.
b John. Mattimoe Assistant General Manager and Chief Engineer 1
F l
F UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l
BEFORE THE ATOMIC SAFETY AND LICENSING APPEAL BOARD t
In the Matter of
)
)
SACRAMENTO MUNICIPAL UTILITY DISTRICT
)
Docket No. 50-312
)
(Rancho Seco Nuclear Generating
)
Station)
)
CERTIFICATE OF SERVICE I hereby certify that copies of Licensee's letter to the Appeal Board with attachments were served this 26th day of March, 1982, by deposit in the U.S. mail, first class, postage prepaid, to the parties identified on the attached Service List.
Thomas A.
- Baxter, P.C.
)
o
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING APPEAL BOARD In the Matter of
)
)
SACRAMENTO MUNICIPAL UTILITY DISTRICT
)
Docket No. 50-312
)
(Rancho Seco Nuclear Generating
)
Station)
)
SERVICE LIST Alan S. Rosenthal, Esquire David S. Kaplan, Esquire Chairman Secretary and General Counsel Atanic Safety and Licensing Appeal Sacramento Municipal Utility District Board P.O. Box 15830 U.S. Nuclear Regulatory &wninsicn Sacramento, California 95813 Washington, D.C.
20555 Richard L. Black, Esquire Dr. John H. Buck Office of the Executive Legal Director Atcmic Safety and Licensing Appeal U.S. Nuclear Regulatory Carrmission Board Washington, D.C.
20555 U.S. Nuclear Regulatory Comnission Washington, D.C.
20555 Christopher Ellison, Esquire California Energy owniasion Christine N. Kohl, Esquire 1111 Howe Avenue Atcmic Safety and Licensing Appeal Sacramento, California 95825 Board U.S. Nuclear Regulatory Cottmission Lawrence Coe Lanpher, Esquire Washington, D.C.
20555 Hill, Christopher and Phillips, P.C.
1900 M Street, N.W.
Elizabeth S. Bowers, Esquire Washington, D.C.
20036 Chairman Atanic Safety and Licensing Board Docketing and Service Section U.S. Nuclear Regulatory Ccmnission Office of the Secretary Washington, D.C.
20555 U.S. Nuclear Regulatory Cbmnission Washington, D.C.
20555 Dr. Richard F. Cole Atanic Safety and Licensing Board Panel U.S. Nuclear Regulatory Comnission Washington, D.C.
20555 Mr. Frederick J. Shan Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Comnissicn Washington, D.C.
20555 1