ML19322B311
| ML19322B311 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/08/1979 |
| From: | Chilk S NRC OFFICE OF THE SECRETARY (SECY) |
| To: | OFFICE OF THE FEDERAL REGISTER |
| References | |
| NUDOCS 7912020159 | |
| Download: ML19322B311 (1) | |
Text
'
{f* "'8
%g
.)
UNITED STATES
.f, NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20655
% "- @T f p
May 8, 1979 OFFICE oF THE SECRETARY Director Office of the Federal Register National Archives and Records Service Washington, D.C.
20403
Dear Sir:
Enclosed for publication in the Federal Register are an original and two certified copies of a document entitled:
DUKE POWER COMPANY Docket Nos. 50-269/270/287 ORDER Publication of the above document at the earliest possible date would be appreciated.
This material is to be charged to requisition number E-146.
Sincerely, Samuel J. Chilk Secretary of the Comission
Enclosures:
Original and 2 certified copies bec:
Records Facility Branch Office of Public Affa~ irs Executive Legal Director Office of Congressional Affairs Office of the General Counsel
)
SECY - C&R Branch 4
~ _ _ _ _ - _.
P bu g
m 31973 M 5D, e...
ea. 7 W UNITED SW."'?3 CF 1MER!CA
"*N N
4 NUC:iAR RECUIXCRY C:2 HISS CN g
)
In de.v tter of
)
Deckets Nos. 50-269 a
)
50-270
- UKE PCWER C
- 2GA:T!
)
and 50-287
)
Cconee Nuclear Station, Units Ncs.1, 2
)
and 3 CFIER I.
"'he Cuke Pcwer Cemeany (te licensee), is ce hcider of Tacility Coerating
- icenses Ncs.
PR-38, PR-47 and CPR-55 wnich audorize the operatien of de nuclear pcwer reactors known as Cconee Nuclear Station, Uni.s Nos.1, 2 and 3 (ce facilities, or Ocenee 1, 2 and 3), at steady sca:e ;cwer levels not in excess of 2562 megawatts de: mal (rated power) for eacn unit.
2.e facilities are Sabecek & Wilcox (3&W) designed pressuri:ed water reactors (Pt R's) located at de licensee's site in Cconee County, South Carolina.
In ne course of its evaluation a s' ate of de accident at de tree.v.ile l
~31and Uni: No. 2 facility, whien utilizes a B&W designed EwR, de Nuclear Regula:Ory Cocnissien staff has ascertained dat 3&W designed reacwrs appear to :e unusually sensitive to cerain off-normal transient con-di:icns Originating in te secondary system.
~he features of the B&W design ca contribute :s this sensitivity are:
(1) the design of stean generators to operate with relatively small licuid volt.=es in de l
790&o9ony_
b
]
M) V m
. se ondary side; (2) the lack of direct initiation of reactor trip upon de occurrence of off-normal conditions in de feedwater system; (3) re-11ance on an integrated control system (ICS) to automatically regulate feedwater flow; (4) actuation before reactor trip of a pilot-operated relief valve on te prinary system pressuri:er (which, if de yalve sticx.s o;:en, can aggravate de event); and (5) a low steam generator elevation (relative c ce reactor vess-eich provides a smaller friving head for natural circulation.
3ecause of :nese features, B&W designed reacecrs place more reliance on te reliabili y and performance characteristics of the auxiliary feedwater system, he :CS, and de energency core cooling system (ICOS) performance to recover from frecuent anticipated transients, suct. as less of offsite powr and loss of nor=al feedwater, than do oder F%R designs. Sis, in turn, places a large burder, on de plant operators in the event of
- ff.cr:al system behavior during such anticipated transients.
A.s a result of a preliminary review of ne Sree Mile Island Uni:
- o. 2 accident chronology, the tac staff initially identified several hucan errors that occurred during de accident and contributed significan.ly to i:s severity. All holders of operating licenses were sucsequently instructed to take a num er of i==edia e actions
^ ~ - -, -
-r-
-~
_,-mm-.
2 w
I.
~
7590-01 3-to avoid repetition of tnese errors, in accordan with bulletirs issued by the Comissien's Office of Inspecticn ard Enforcement (IE).
In addition, tne NPC staff cegan an 1 mediate reevaluaticn of the design features of B&W reacters to determine vnetner additional safety correcticas er irgrovements were necessary wish res.:ect to these reacters. Tnis evaluation involved numerous restings with B&W and certain of the affected licensees.
The evaluatien identified design features as discussed above whicn indicated that 3&W designed reactors are unusually sensitive to certain off-ncreal transient conditiens criginating in the secondary system. As a result, an cdditional bulletin was issued by IE which instructed holders of cceract.7 licenses for B&W designed reactors to take further actions, including imrediate enanges to decrease the reactor hign pressure trip point ard increase the pressurizer pilot-eperated relief valve setting. Also, as a result of this evaluation, the RC staff identified certain other safety concerns i
.nat warranted additicnal shcrt-term design and procedural enanges xerating facilities having S&W designed reactors.
These were at identified as ice.m (a) througn (e) on page 1-7 of ne Office of Nuclear Reacter Regulation Status Report to tne Cc=ission on Apri' 25,1979.
j
,,y ye
-m m
-W*"
E
f a
m 4
7590-01 A.fter a serias of discussions ::etween the NRC staff and tne licensee concerning possible design aedificatiens and enanges in operating procedures, the licensee agreed in letters dated April 25, 26, and May 4,1979 to perform pec@tly the following acticns:
(a)
Install autecatic starting of the interconnected emergency feedwater system so that all enree pumps will receive a start signal from any affected unit, and test the system for stabil-ity. Tne energency feedsater puq discharge flow will be connected to tne interconnection headers sucn tnat each or all e.ergency feedwater pumps can supply water to any unit.
Until enese redifications and tests are completed, operating persennel have been stationed at each emergency feedsater pump wien a direct cornunicatien link to tnat unit's control rocc.
In additien, the following procedural enanges, put inte effect en April 25, 1979 to ennance the reliacility of
- ne e.ergency feedsater system, will retain in force:
l (1) The cischarges of tnese puncs have been tied to-gether by alignrent of ranual valves such that each and all of the purps can supply emergency feedsater to any Ocenee Unit requiring it.
~ -
+v,-
.a.,--ww w- -~
e,.
w,-
n.~,...c
r.
9 7590-01
, (2)
Administrative centrols have been estaclished so that in the even*. cf less of both rain feedwater pu::ps on an affected unit, tnat unit's eargancy feedwater pur:p will start automatically, ::acked up by renote
- nanual start from the control room.
If the pu:p' fails to start aute:natically, the operator stationed at that pu:tp will start the pu::p locally, and nas been trained to do so.
In addition, the other two available emer-gency feedwater pu=s will be started remotely from their unit's centrol room or locally if required to pro-vide two ::cre redundant sources of feedwater to the affected unit.
r (3)
E:nergency feedwater flow to tne steam generators will be assured by the control room operater who has been trained to ::aintain the necessary level.
(b)
Develop anc implement operating procedures for initiati.w and controlling emergency feedwater independent of Integrated Centrol System control.
(c)
I::plement a hard-wired control-grade reactor trip en loss of rain feedwater and/or turbine trip.
S' P#-
-M Np wh-***-gge.igni,i_
Y y
I O
3
.)
- (d)
Complete analyses for potential small breaks and develop and inplement operating instructions to define operator action.
(e)
All licensed reactor operators and senior reactor operators will have completed the 'IMI-2 simulator trainine at B&W.
(f)
Station in the control room an additional full-time Senior Reactor Cperator (SRO) (or previously licensed SRO) with Three Mile Island training for each operating unit to assist with guidance and p::ssible manual action in case of transients until items (a) through (e) are completed.
In its letters the licensee also stated that (1) Oconee 3 would be shut dow. on April 28, 1979, and remain shutdown until (a) through (e) a:cve are completed (the facility was shut down on April 23, 1979 as stated); (2) a second Oconee unit would be shut down on May 12, 1979, if itecs (a) through (e) have net been previously accomplisned and remain shut down until items (a) through (e) have been ccmpleted; and, (3) a third Oconee unit would be shut down on May 19, 1979, if items (a) through (e) have not been previously accomplished and will remain shut down until ecmpletion of items (a) through (e).
r n
.)
7-In addition to these modifications to be implemented promptly, the licensee has also proposed to carry out certain additional lorg-term actions to increase the capability ard reliability of the reactors to respond to various transient events. mese are:
The licensee will install two motor driven pr.ps for each Oconee unit, as more particularly described as Part III of_ a letter from W.O. Parker to the EC of April 25, 1979, to provide greater assurance of emer-gency feedwater supply. The licensee will submit. this system concept and analysis to the EC staff for review.
l The licensee will submit a failure mode and effects analysis of the Integroced Control System to the EC staff as soon as practicable. The licensee states that this analysis is now I
underway with high priority by B&W.
The reactor trip on loss of the main feedwater and/or trip of the turbine to be installed promptly pursuant to this Order will thereafter be upgraded so that the comp nents are safety grade.
Se licensee will sutnit this design to the EC staff for review.
The licensee will continue reactor operator training and drilling of response procedures to assure a high state of preparedness.
l
.m
-=w
..a A
.m,eme-w m.-
v..-*%v.
.ge w +*., p agp w, * - e- % h e.-=--,-%.
-e
=e-w.-e-1
7590-01 '
a-Tne Ccmission has concluded that the prengt actions set forth as (a) through (e) aMve are necessary to provide added reliability to the reacecr system to respend safely to feedwater transients and snculd be confirred by a Comissien order. The imediate pro-cedural changes to assure redurdant sources of auxiliary feedwater tnat were put into effect on April 25 at the two operating Oconee units, as described -in paragrapn (a) above, and tne imediate additions to the operating staff, as described in paragraph (f)
I arove, provide the bases for centinued safe cperation of those facilities during the interim period until May 12 and May 19, 1979, respectively. The Comissien finds, however, that operation of all units should not be resumed or centinued on an indefinite casis until actions described in paragrapns (a) through (e) above i
have been satisfactorily congleted.
1 l
l Fcr the foregoing reasons, the Comission has found enat the public health, safety and interest require tnat enis order ce effective i::nediately.
III.
Ccpies of the following documents are availacle for inspection at tne Ocmission's Punlic Document Room at 1717 B Street, N.W.,
Washingten, D.C. 20555, and are ceing placed in tne Comission's local public doc.: ment room at the Oconee County :.ibrary, 201 South 5pring, Walhalla, South Carolina 29691:
r-r
~
-)
J 7590-01
' (1) Office of Nuclear Reactor Regulaticn Status Report on Feedwater Transients in B&W Plants, April 25, 1979.
(2)
Letter from W. S. Lee (Duke Power Cogany) to Harold Denton (NRR), dated April 25, 1979.
(3) Two letters frem W. O. Parker, Jr. (Duke Pcwer Cogany) to Harold Centen (NRR)., dated April 25, 1979.
(4)
Letter from W. H. Owens (Duke Power Cogany) to Roger J.
Mattson (NPR), dated April 25, 1979.
(5)
Letter from W. S. Lee (Duke Power Cogany) to Harold Denton (NRR), dated April 26, 1979.
(6)
Letter from W. O. Parker, Jr. (Duke Power Ccgany) to Janes P. O'Reilly (IE), dated May 4,1979.
IV.
Accordingly, pursuant to the At mic Energy Act of 1954, as amended, and the Commission's Rules and Regulatiens in 10 CFR Parts 2 and 50, IT IS HEREBY ORCERED 'DiAT:
(1) The licensee snall take the following actions with respect to Oconee 1, 2 and 3:
(a)
Install automatic starting of :ne interconnected emergency feedwater system so that all tnree pugs will receive a start
9 9
7590-01
. signal frcm any affected unit, and test the system for stability. The emergency feedwater pump discharge flow will be connected to the interconnection headers such that each or all of the emergency feedwater punps can supply water to any unit. Until these modifications and tests are cenpleted, cperating persennel will ce stationed at each emergency feedwater pu::p with a direct centunication link to that unit's centrol room.
In addition, the following procedural changes, put into effect cn April 25, 1979 to enhance the reliability of the emergency feecwater system, will remain in force:
(1) The discharges of tnese pungs have been tied to-gether by alignment of manual valves such tnat eaca and all of the punps can supply-emergency i
feedsater to any Oconee Unit requiring it.
(2)
Ad:ninistrative centrols have been established so that in the event of loss of both main feedwater pungs on an affected unit, that unit's emergency feedwater pu::p will start autertatically, backed up cy reacte manual start frem the control room.
If tne pung fails to start automatically, the operator stationed at enat pung will start the pu p locally, and nas oeen trained
,p
J' to do so.
In addition, the other two available emer-gency feedwater pumps will be started ruotely from their unit's control room or locally if required to pro-vide two more sources of feedwater to the affected unit.
(3) Emergency feedwater flow to the steam generators will be assured by the control room operator who has been trained to maintain the necessary level.
(b)
Develop and implenent operating procedures for initiating and controlling emergency feedwater independent of Integrated Control System control.
(c)
Implanent a hard-wired control-grade reactor trip on loss of main feedwater and/or turbine trip.
(d)
Complete analyses for potential small breaks and develop and implement operating instructions to define operator action.
(e)
All licensed reactor operators and senior reactor operators assigned to the Oconee control rooms will have completed the
'IMI-2 simulator training at B&W.
-- _. =...
touy-ui n
J
. (f)
Station in the crqtrol room an additional full-time Senior Reactor Operator (SRO) (or previously licensed SRO) with tree Mile Island training for each operating unit to assist with guidance and possible =anual actions until items (a) through (e) are completed.
]
(2) The licensee shall maintain Oconee 3 in a shut down c: Jition (the facility was shut down on April 28, 1979) until items (a) through (e) in paragraph (1) above are satisfactorily completed and such com-pletion has been confimed by the Director, Office of Nuclear Reactor Regulation.
(3) The licensee shall shut down a second of the three Oconee units on May 12, 1979, unless items (a) through (e) in paragraph (1) above have been satisfactorily completed and the completion has been confirmed by the Director, Office of Nuclear Reactor Regulation, before that date.
In the event the second unit is shut don on May 12, 1979, it will remain shutdown until items (a) through (e) in paragraph (1) above are satisfac*wrily com-pleted and such completion has been confimed by the Direcwr, Office of Nuclear Reactor Regulation.
m
. _ _ _ _. _. _. - ~. _ _ _. _ _ _ _
f
}
7590-01 (4)
The licensee shall shut down the tnird of the tnree Oconee units on May 19, 1979, unless items (a) through (e) in paragraph (1) above have been satisfactorily cogleted and the ccqletion has been confir ed cy the Director, Office of Nuclear Reactor Regula-tien, befcre that date.
In tne event the third unit is shut down on May 19, 1979, it shall re: rain shut down until items (a) through (e) in paragraph (1) above are satisfactorily cc@ leted and sucn cogletion has been confi=ed by the Director, Office of Nuclear Reactor Regulation.
(5)
The licensee shall as prcqtly as practicable also accom-plish the long-term modifications set forth in section II of this Order.
5atisfactory cc::pletien of items (a) through (e) in paragrapn (1) and in paragraphs (2) tnrcugh (4) acove will require confir: ration by the Direct 0r. Office of Nuclear Reactor Regulaticn, that the actions specified have ceen taken, the specified analyses are acceptable,
'and the specified iglementing procedures are appropriate.
V.
Within twenty (20) dois of tne date of this Order, the licensee or any person wncse interest may ce affected cy tnis Or6er may
o 9
f 7590-01 14 -
i request a hearing with respect to this Order. Any such request snall not stay the 1::Inediate effectiveness of this Order.
1 i
f EOR THE ITJCLEAR PELT.AICFY COMMISSION
)
hd
(
l
.asrue2 m C.._k N
Secretary p the Comission Cated at Washington, DC i
this7fdayof 1979.
f I
i*wN -mm
,...we.
%w-, -,.wme... e ww w.w f
=w---we y -
w.
3 w-pm
-4 g-a-w.-
- -r/