ML13308A107
| ML13308A107 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/05/1982 |
| From: | Shewmon P Advisory Committee on Reactor Safeguards |
| To: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML13308A105 | List: |
| References | |
| NUDOCS 8204210124 | |
| Download: ML13308A107 (4) | |
Text
,0 UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 April 5, 1982 Mr. Willian J. Dircks Executive Director for Operations U. S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Dircks:
Subject:
RELIABILITY OF THE SHUTDOWN HEAT REMOVAL SYSTEM ON THE SYSTEM 80 DESIGN The ACRS in its December 15, 1981 report to Chairman Palladino on the Combustion Engineering, Inc. Standard Reference System 80 commented on the reliability of the decay heat removal system.
These comments addressed the lack of a capability for rapid, direct depressurization of the primary sys tem to allow feed and bleed operations and the reliance placed upon the secondary system for heat removal capability.
The ACRS Subcommittee on Decay Heat Removal Systems met with representatives of Combustion Engineer ing, Inc. and the NRC Staff on March 16, 1982 to discuss these issues.
The ACRS discussed these issues further during its 264th meeting, April 1-2, 1982.
Representatives of Combustion Engineering have defended their design, stat ing that:
- 1.
The System 80 NSSS will be coupled with highly reliable emergency feedwater systems (EFWS) by addition of an interface requirement that the EFWS have an unavailability in the range of 104 to 10-5 per demand.
- 2. The System 80 NSSS is capable of achieving cold shutdown conditions using only safety grade systems even without offsite power and with an added single failure.
- 3. The System 80 steam generator design includes many features that will assure adequate tube integrity, minimizing concerns associated with operating reactors.
- 4.
Even if all auxiliary feedwater supply were somehow lost, the secon dary side of the steam generators could be depressurized to allow use of low head pumps which might be aligned to provide water to the steam generators from a number of sources.
- 5. Probabilistic analyses have not shown that installing PORVs will result in a significant improvement in safety.
The added costs are not justified.
8204210124 820408 PDR ADOCK 05000361 P
William J. Dircks 2 -
April 5, 1982 Combustion Engineering has proposed that the issues associated with the Committee's comments on the System 80 design be resolved in a continu ing dialogue among the ACRS, the NRC Staff, and Combustion Engineering.
It is the NRC Staff's intention to address these issues on an expedi tious schedule with all applicants requesting licenses for Combustion Engineering NSSS designs which do not have capability for rapid depres surization independent of the steam generator. We concur with this ap proach and wish to be kept informed.
The Combustion Engineering response to the Committee's comments on the System 80 design emphasizes the expected very high reliability of the feedwater systems and the integrity of the steam generators. We believe that these are necessary goals, but note that past operating experience indicates that these goals are difficult to achieve.
We believe that for this reason Combustion Engineering and the NRC Staff should consider fur ther the addition of valves of a size to facilitate rapid depressuriza tion of the System 80 primary coolant system as stated in the Committee's December 15, 1981 letter on the System 80 design. We believe that a plan for addressing this issue should be formulated in the near future. We wish to be kept informed and to discuss this further with Combustion Engineering and the NRC Staff.
We believe that, while this evaluation should be conducted expeditiously, its resolution should not now be a condition for operation of System 80 plants at full power, or of plants having similar features.
The need for future hardware or procedural changes should be contingent upon results of this evaluation.
Sincerely, P. Shewmon Chairman
DISTRIBUTION OF BOARD NOTIFICATION San Onofre 1&2 Docket Nos.. 50-361/362 ACRS Members James A. Beoletto, Esq.
Dr. Robert C. Axtmann Louis Bernath A. S. Carstens Dr. Max BenCar Samuel B. Casey, Esq.
Dr. Jes.
Eboe Gary D. Cotton Mr. Harold Eeron Stephen F. Eilperin, Esq.
Dr. Wil Ker Phyllis M. Gall-agher, Esq.
Dr. Ha Wewi Lawrence Q. Garcia, Esq.
Dr.
aron W
ark Dr. Reginald L. Gotchy Dr. WilCamson Mats Dr. Cadet H. Hand, Jr.
Dr. Da W. M thle Mrs. L yi.Harris Hicks Dr. Dad oet Mrs. Elizabeth B. Johnson D.DvdOrn DrW. Reed Johnson Dr. Milton S. Plesset Dr.W. eedJohsonMr.
Jeremiah J. Ray James L. Kelley, Esq.
Dr. Paul G. Shewmon Janice E. Kerr, Esq.
Dr. Chester P. Siess Mr. Charles R. Kocher Mr. David A. Ward Charles E. McClung, Jr., Esq.
John A. Mendez, Esq.
David R. Pigott, Esq.
Edward B. Rogin, Esq.
J. Calvin Simpson, Esq.
Daniel K. Spradlin, Esq.
Alan R. Watts, Esq.
Richard J. Wharton, Esq.
Water ford Docket No. 50-382 E. Blake, Esq.
Mr. Luke Fontana Dr. Harry Foreman Mr. Stephen M. Irving Mr. Lyman L. Jones, Jr.
Dr. Walter H. Jordan Mr. M. Stevenson Sheldon W.
Wolfe, Esq.
Atomic Safety and Licensing Board Panel AtomicDSafety and Licensing Appeal Panel Docketing and Service Section Document Management Branch
BOARD NOTIFICATION DISTRIBUTION Docket File 50-382 & 50/361/362 guA.Xyd LPDR ACRS (16)
PDR NSIC TERA LB#3 Files DEisenhut RPurple SVarga DVassallo RClark JStolz R.Tedesco BJYoungblood ASchwencer FMiraglia JMiller EAdensam DCrutchfield WRussell TIppolito RVollmer HThompson RMattson SHanauer BSnyder RHartfield, MPA MJollenstein (4)
JScinto (2)
EChristenbury (1)
HDenton ECase PPAS MWilliams SBlack & HRood PM JLee bcc:
WJDircks VStello GCunningham IE (3)