ML19308C800
| ML19308C800 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Palisades, Saint Lucie, Midland, Crane  |
| Issue date: | 11/18/1976 |
| From: | Moeller D Advisory Committee on Reactor Safeguards |
| To: | Rowden M NRC COMMISSION (OCM) |
| Shared Package | |
| ML19308C802 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8002070532 | |
| Download: ML19308C800 (3) | |
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- 8 ADVISORY CO.WalTTEE ON REACTOR SAFEGUARDS t
WASHINGTON, D. C. 20555 November 18, 1976 y
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Honorable Marcus A. Rowden y.;
Chairman i-U. S. Nuclear Regulatory Comission
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Washington, DC 20555
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Subject:
, SUPPLEMENTAL REPORP ON MIDLAND PLANT UNIfS 1 AND 2 k.I'
Dear Mr. Rowden:
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In response to a request from Chairman D. M. Head of the Midland Atomic
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Safety and Licensing Board, the Advisory Comittee on Reactor Safeguards
, has reviewed the record pertaining to the Midland Plant Units 1 and.2
,', 3 as reported in its letter of June 18, 1970. D e items listed below are j:
those items referred to in its paragraph on "other problems related to p,'s, i
large water reactors" which had been previously " identified by the Reg-0' ulatory Staff and the ACRS," and which the Comittee considered applicable to the Midland Plant.
Following each item, the Comittee has included an amplifying statement based on ACRS reports on other similar commer-cial nuclear reactor power plants which had been reviewed during the months prior to the Comittee's review of the Midland Plant. Copies of the referenced ACRS reports are attached.
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Separation of protection and control instrumentation - h e Applicant u,::
proposed using signals from protection instruments for control purpos,es.
_ The Committee believed that control and protection instrumentation should p'M be separated to the fullest extent practicable, and recommended that the L
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/ Applicant explore further the possibility of making safety instrumentation M-more nearly independent of control functions.
(Wree Mile Island,1/17/68)
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Vibratiion and loose parts monitoring - We Comittee r;.comended that the Applicant study possible means of in-service monitoriig for vibration b
- or the presence of loose parts in the reactor pressure ves;;el as well as f '!
in other portions of the primary system, and implement such means as
,j found practical and appropriate.
(Pa* *sade's,1/27/70).
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Potential for axial xenon oscillations - he Applicant was continuing Li "--
studies on the possible use of part-length rods for stabilizing potential j-xenon oscillations. - Solid poison shims were to be added to the fuel elements if necessary to make the moderator temperature coefficient more c hl
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gg negative at the beginning of core life.
(%ree Mile Island,1/17/68).
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.p Honorable Marcus A. Rowden November 18, 1976 4[
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-4. - The behavior of core-barrel check valves in' normal operation - ne
?T Applicant had proposed core-barrel check valves between the hot leg and
'the cold leg to insure proper operation of the ECCS under all circum-
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stances. Analytical studies had indicated that vibrations would not f
unseat these valves during normal operation. The Comittee desired that
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.this point be verified experimentally.
(Three Mile Island,.1/17/68).
5.
The potential consequences of fuel handling accidents - We Committee l;}
believed that further study was required with regard to potential releases p$!:4 of radioactivity in the unlikely event of gross damage to' an irradiated.
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subassembly during fuel handling and the possible need for a charcoal
'S filtration system in the fuel handling building. The Comittee recomended that this' matter be resolved in a' manner satisfactory to the Regulatory
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Staff.
(Hutchinson Island, 3/12/70).
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The effects of blowdown forces on core internals - We Comittee
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recommended that the Regulatory Staff review the effects of blowdown forces on core internals and the development of appropriate load combi-j.
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' nations and deformation limits.
(Three Mile Island,1/17/68).
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Assurance that LOCA-related fuel rod failures will not interfere with
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ECCS function - The Committee desired to emphasize the importance of work 4.
to assure that fuel-rod failures in loss-of-coolant accidents will not g [d affect significantly the ability of the ECCS to prevent clad nelting.
(Three Mile Island,1/17/68).
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4 The effect' on pressure vessel integrity of ECCS induced thermal
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shock - The Comittee recommended that the Regulatory Staff review anal-yses of porsible effects, upon pressure-vessel integrity, arising from
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I-thermal shock induced by ECCS operation.
(Oconee, 7/11/67)'.~
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Environmental qualification of vital equiEment in containment - he
%M Committee reconmended that (2tention be given to the long-term ability g.@
of vital conponents, such as electrical equipment and cables, to with-v.9 stand the environment of the containment in the unlikely event of a loss-j of-coolant accident. - (Palisades,1/27/70)..
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- 10. Instrumentation to follow the course of-an accident - This iten.related
.to the development of systms to control' the buildup of hydrogen in the c
$?I containment, and of instrumentation to monitor the course of events in the
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Lunlikely event of a loss-of-coolant accident.
(Hutchinson Island, 3/12/70).
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.r Honorable Marcus A. Rowden November 18, 1976
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- 11. Improved quality assurance and in-service inspection of primary sys-tem - The Committee continued to emphasize the importance of quality as-surance in fabrication of the primary system as well as inspection during M;
service life, and recommended that the Applicant implement those improve-ments in quality practical with current technology.
(Oconee, 7/11/67).
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Sincerely yours,
.f Dade W. Moeller
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Chairman
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Attachments:
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Request from Chairman D. M. Head, AS&LB, dated 10/14/76 y J.
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Report on Midland Plant Units 1 & 2, dated 6/18/70
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Report on Hutchinson Island Unit No.1, s
dated 3/12/70 4.
Report on Palisades Plant, dated 1/27/70 5.
Report on Three Mile Island Nuclear:
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Station Unit 1, dated 1/17/68
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Report on Oconee Nuclear Station,
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Units 1, 2, and 3, dated 7/ll/67
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