ML20129J011
| ML20129J011 | |
| Person / Time | |
|---|---|
| Issue date: | 07/05/1985 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rossin D NUCLEAR SAFETY ANALYSIS CENTER |
| Shared Package | |
| ML20129H990 | List: |
| References | |
| NUDOCS 8507220140 | |
| Download: ML20129J011 (2) | |
Text
_
)
. ww-= v, ew - ;~+ -.w.ym mg
~-
oc ,.~cL
~
jet 05 M Dr. David Rossin, Director Nuclear Safety Analysis Center 3412 Hillview Avenue P.O. Box 10412 Palo Alto, California 94303
Dear Dr. Rossin:
Subject:
Request for Peer Review Comments - Preliminary Case Study Report --
Decay Heat Removal Problems at U.S. Pressurized Water Reactors A preliminary case study on DHR losses at operating PWRs is attached. The study analyzes 130 losses of DHR systems at U.S. PWRs between 1976 and 1983 and notes that for some likely events, a loss of DHR can result in core uncovery within one to three hours.
Our case study report indicates the root causes of the DHR losses, and it examines specific actions that have been taken at several plants to improve the availability of their DHR systems. The report makes six recommenda-tions, which if implemented, will significantly reduce the frequency, ddration and severity of loss-of-DHR events.
b accordance with our " peer review" process prior to the finalization and distribution of our case study reports, we are providing NRR, IE, Regional Offices, RES, NSAC and INPO with a copy of a preliminary report for review and comment, particularly regarding accuracy and completeness of the technical details. Changes to the findings, conclusions, and recommendations will be considered only if the underlying infomation concerning the details of plant design or systems operation is in error. Therefore, comments are being solicited on the technical accuracy of the report. The findings, conclusions, and recommendations are provided for your infomation in order that you may understand the significance AEOD places on these events and, therefore, obtain a more complete picture of the total report. We would welcome comments either infomally by telephone or fomally by memorandum.
Since we wish to finalize and issue the report shortly, we ask that any comments be received by us within 30 days from receipt of the preliminary copy. Should you require some additional time beyond that point, please let us know; otherwise, it will be assumed that there are no comments.
8507220140 850705 PDR MISC 8507220107 PDR
- u 5 oPo 2 S8 3-400 24 7 NRC NRM 318 HO'80l NRCM O2" OFFICIAL RECORD COPY
~~
- & , wr; 4
- xy== =-~=x=1, py
- n.m = m,.xm ~:;r:y p q; m
)
-- + m --> e 3 3 ~; y Dr. David Rossin -
2-As you may know, AE00 reports do not represent an official tiRC position or the position of the responsible itRC program office. Our reports are one input to an ongoing review and evaluation process, and any recoianendation contained in our final report will be considered and perhaps modified or eliminated by the responsible tiRC office.
A copy of the preliminary report and this letter are being placed in the Public Document Room at 1717 H Street, N.W., Washington, D.C. 20555.
If you have any questions regarding this study, please feel free to contact Dr. Hal Ornstein at (301)492-4439.
Sincerely,
]C C. J. Heltenes, Jr., Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
G. Vine Distribution 7 PDR AE0D CF ROAB CF ROAB SF H0rnstein WLanning KSeyfrit TIppolito CHeltemes
"'c'> . . .C ROAB. . d. .00:AE . . . 0.:.A 0 7 . .. . . . . . . . . .. . ........
db ...S$C.:EAB."f. ..
- ""> .H.0,rns t9,1 n :,,,,,,Ma,,WLann1n KSey,{yi,t,,,, TIppo ,, , ,,,,,,, ,
CH h emes , , ,, , , ,,, , ,, ,, ,,, ,,,,,,,
06/.g, 07/7/85 ocar) 06/6/.85
.. ..... .. .. .. . . . . . . . . . . t./ .8.06/2'
........ ... .... ...)......./85
- 5. . . . . . /. / 8 5OW(./1 . .. ... .. ... . . . . . . . . . . . . . . . . . . . . . . . . . . .
- u.s. opo is 3-4oo.247 8 c ronu us no soinacu o24o OFFICIAL RECORD COPY
.n, .. -, .- ~ c .. _ =
l