ML19254E916
| ML19254E916 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/23/1979 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| Shared Package | |
| ML19254E917 | List: |
| References | |
| NUDOCS 7911050058 | |
| Download: ML19254E916 (2) | |
Text
..
a.
["***
- UNITED STATES O
j t,
NUCLEAR REGULATORY COMMISSION g
a -
wasHlNG TO N, D. C. 20555
,f
/
i" 00cket t:os.: 50-327 50-328 Mr. H. G. Parris Manager of Pr"er Tennessee Valley Authority 500A Chestnut Street Tower II Chattanooga, Tennessee 37401
Dear Mr. Parris:
SUBJECT:
P0TENTIAL UNREVIEWED SAFETY QUESTION ON INTERACTION BETWEEN NON-SAFETY GRADE SYSTEMS AND SAFETY GRADE SYSTEMS You were informed by IE Information Notice 79-22, issued September 14, 1979, that certain non-safety grade equipment, if subjected to an adverse environ-ment, could impact the safety analyses and the adequacy of the protective functions performed by safety grade equipment.
Enclosed is a copy of IE Information Notice 79-22, and reprinted copies of an August 30, 1979 Westinghouse letter and a September 10, 1979 Public Service Electric and Gas Company letter which address this matter.
The NRC is concerned that a similar potential may exist at other op9 rating
~
light water reactor facilities, including yours, for an unreviewed scfety matter related to the effects of the environment on control systems resulting from high energy line breaks inside or outside containment and the results of these effects on the required safety systems.
You are requested to submit by October 30, 1979, the information requested in Bulletin O 79-22. Please call if there are questions.
Sincerely,
.5 u kt i L. S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Project Management
Enclosures:
1.
IE Information Notice 79-22 2.
Westinghouse's August 30, 1979 Letter (Reprint) 3.
Public Service Electric & Gas Company's September 10, 1979 Letter (Reprint) cc w/ enclosures:
See next page 1268 277 OM 7911050 9*
Tennessee Valley Authority OCI 2 3 WL' ccs:
Perbert S. Sanger, Jr. Esq.
General Counsel Tennessee Valley Authority 400 Connerce Avenue s '-
EllB33 Knoxville, Tennessee 37902 Mr. E. G. Beasley Tennessee Valley Authority 400 Commerce Avenue W10Cl31 C V,noxville, Tennessee 37902 Mr. Michael Harding Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. David Lambert Tennessee Valley Authority 400 Chestnut Street Tower II Chattanooga, Tennessee 37401 F
~.
1268 278 s.:
w:
L.s':.
'.y Ws'.
- 's
. t.. -
- i w.
W L
.'fA u.
- {,K f ' '
y
~,
' ' ~. '
6 ENCLOSURE 1 UNITED.TATES NUCLEAR REGULMORY COMISSIC.N OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September la. 1979
'E Inf or ation Notice No. 75-22 QUALIFICATION OF CONTROL SYSTEMS Public Service Electr and Gas Company nctified the HEC cf a potential unrevia-ed safety question at their Salem Unit 1 facility.
This notification was based on a continuing review by Westinghouse of the envir. n.Tental cualifications of equincr.;
that they supply for nuclear steam supply syst M s.
Eas e:: on the ?rcsent statin:
of this ef fort, Westinghouse has infomed tncir cus tcmers that the performan:e of non-safety grade equipment subiected to an adverse cavironNnt could i? pact the protective f unctions performed by safety grade eqJipNnt.
These non safety grade systems include:
Steam generato power operated relief valve control system Pressurizer power operated relief valse control system Main feec-ater control syste.T Automatic,.ref control system These systems could potentially malfunction due te a high energy lina break inside or outside of containment.
NRC is also concerned that the acverse environment could also give erroneous information to tne plant operators.
Westinghouse states that the consequences of such an event c0uld possibly be more limiting than results presented in Safety Analysis Reports, however, Westinghouse also states that the severity of the results can be limited by operator actions together with operating characterisitics of the safety systems.
Further, Westinghouse has recommended to their cestemers that tney review their systems to determine whether any unrevie-ed safety questions exist.
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that ter:ipients will review the infom.atien for possible applicability to their facilities.
No soecific actica or response is requested at this time.
If NRC evaluations so incicate, fur.her licen:,ce actions may b3 requested or required.
If you have questi:ns regarding this matter, please conta..:t the Directar of the appropriate NRC Regional Office.
No written response to this Information Notice is required.
[
d 1268 279