ML20247L856
| ML20247L856 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 05/25/1989 |
| From: | Adensam E Office of Nuclear Reactor Regulation |
| To: | Cottle W SYSTEM ENERGY RESOURCES, INC. |
| References | |
| 2.206, NUDOCS 8906020280 | |
| Download: ML20247L856 (2) | |
Text
.
y s.
S May 25, 1989 g
i Docket No. 50-416 Mr. W. T. Cottle L
Vice President, Nuclear Operations i
System Energy Resources, D c.
Post Office Box 23054 Jackson, Mississippi 30205
Dear Mr. Cottle:
I'
SUBJECT:
DIRECTOR'S DECISION IN RESPONSE TO 2.206 PETITION REGARDING BWR STABILITY Enclosed for your information are copies of a Director's Decision, letter of transmittal and Federal Register notice issued by the Director, Office of Nuclear Reactor RegulHion (Director) in response to a Petition filed under 10 CFR 2.206 of the Commission's regulations.. The Petition was filed by Ms. Susan Hiatt on behalf of the Ohio Citizens for Responsible Energy-(OCRE).
The Petitioner expressed concerns regarding the March 9, 1988 power oscillation event at LaSalle, Unit 2 and requested that the Director and Commission take specified action with respect to all boiling water reactors. As discussed in the enclosed Director's Decision, the Petitioner's request under 10 CFR 2.206 has been denied.
However, the Petitioner's request to reopen rulemaking proceedings regarding Anticipated Transients Without Scram (ATWS) is being treated as a petition for rulemaking under 10 CFR 2.802 of the Commission's regulations.
Please contact me at (301) 492-1466 if you have any questions on this issue.
Sincerely, Original Signed By:
Elinor G. Adensam, Director Project Directorate I1-1 Division of Reactor Projects -I/II Office of Nuclear Reactor Regulation
Enclosure:
- 1. Lettec dated April 27, 1989 to Ms. % san L. Hiatt
- 2. Director's Decision dated April 27, 1989
- 3. Federal Register Notice dated April 27, 1989 cc w/encls:
See next page 8906020280 690525 PDR ADOCK 05000416 P
(
h LA 1
PM.
I -1 D:P
-1 f
PA erson LKintner:sw EA e y m l
Mg 5/yL'/89 05/gy/89 05/p89 l
j
\\
_______----------__----____--_.-a
y I
- 14) ', - '
e,1,
!!'?
a..
- f.
DISTRIBUTION Desiu w d tle' NRC PDR.
W!
Local PDR.
PDIIal-Reading
~S. Varga
.14-E-4.
_ G. Lainas
'14-H-3.
E..Adensam'< B-20 P. Anderson 14-B-20 L. Kintner' 14-B-20 OGC; IS-B-18 D. Hagan MNBB-3302.
E. Jordan '
MNBB-33021 B. Grimes-9-A-2 7T.'LMeek (4.cys forleach Docket No.)
P1-137 Wanda Jones' P-130A:
E. Butcher-11-F-23
'ACRS-(10) "
P-315' GPA/PA.,
17-F _ ARM /LFMB-AR-2015 CBuracker 9-D-24>
l'
-o hr I
i o
ONI
' i j
'.s ENCLOSURE 1 f",co on s,
'c.
UNITED STATES o
i
.t'
?
NUCLEAR REGULATORY COMMIS$10N I
j msmissetom. c. c. rossa
\\.'...,e!
DD-89-03 April 27, 1989 Ms. Suser L. Hiatt Representative of Ohio Citizens for Responsible Energy, Inc.
8275 Munson Road Mentor, Ohio 44060
Dear Ms. Hiatt:
This letter is in further response to your Petition ofW1y 22,1988 requesting that the Director, Office of Nuclear Reactor Regulation (NRR), take Ismediate action with respect to boiling water reactors (BWRs) to relieve what you allege to be undue risks to the public health and safety posed by the thermal-hdraulic instability of BWRs as revealed by an event at LaSalle County Station, Unit 2, on March g, 1988.
On August 26, 1986, I informed you that your request for issediate relief was denied because the allegations that fore the basis for your Petition did not reveal any new operational safety issue that posed an ismediate safety concern for continued BWR operation.
I also informed you that your Petition was being treated under 10 CFR 2.206 of the Cosmission's regulations and that appropriate action, that is, a formal decision, would be taken within a reasonable time.
For the reasons set forth in the enclosed Director's Decision under 10 CFR 2.206, your Petition has been denied. However, as discussed belor, p o request.to reopen rulemaking proceedings regarding anticipated transiehss without scram (ATWS) is being treated as a petition for rulemaking under 10 CFR 2.802 of the Comission's regulations. A copy of the Decision will be filed with the Secretary of the Cosmission for the Cosmission's review in accordance with 10 CFR 2.206.
The Decision will constitute final action of the Coemission 25 days after the cate of issuance unless the Commission, on its own motion, institutes a review of the Decision within that tiet.
In the August 26, 1988 letter, I acknowledged your request to reopen rulemaking proceedings regarding ATWS as part of the relief requested. However, since that time, I have determined that this request is more properly treated as a petition for rulemaking under 10 CFR 2.802 of the Commission s regulations. As such, it has been referred to W NRC Office of Research for appropriate action. However-l it is important to nc,te tnat both the NRC and BWR Owners Group (BWR06) currently have prograr.s in which analyses of ATWS conditions are being conducted. These analyses treat large amplitude power oscillations with state-of-the-art analytical methods. The results of these analyses to datt confire the technical bases for the current ATWS rule. Consequently, at this time, the NRC staff sees no basis for recommending that the Commission reopen rulemaking proceedings regarding ATWS.
{
If, however, the staff finds evidence which contradicts the assumptions and results of previous ATWS O dy ses fn7 either the information you provided in support of your Petition Ot newinfoitationfrorongoingNRCandBWROGproprams,itmay then be appropriate for the Comission to reconsider the current A VS rule.
Susar$L.Hiatt For your information, I am enclosing a copy of Supplement I to NRC Bulletin No. 65-07, " Power Oscillations in Boiling Water Reactors", which is referenced-in the Director's Decision.
I am also enclosing a copy of the notice regarding this Decision that was filed with the Office of the Federal Register for publication.
Sincerely, r%i10
/
Thomas E. Murley Office of Nuclear, Director Reactor Regulation
Enclosures:
- 1. Directer's Decision
- 2. Federal Recisty Notice
- 3. NRC bulletin No. 88-07, Supplement I l
I d
e 4
l
?
. - _ -. _ - - -. _ _ _ _.. - - - _ _. - - _. _ -. _ _ - - _ _ - - - ~ _ _ _ _ _ _. - - - - _. - -. _ _ - _ _. - -
L j
ENClosung g
'l 00-89 IJ UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION 0FFICE OF NUCLEAR REACTOR REGULATION Thomas E. Murley, Director
~In the Matter of BOSTON EDISON CD. (Pilgrim Nuclear Power Station, Docket No. 50-293)
CAROLINA POWER & LIGHT CO. (Brunswick Station, Units 1 and 2 Docket Nos. 50-324 and 50-325)-
CLEVELAND ELECTRIC ILLUMINATING CO., ET AL. (Perry Nuclear Power Plant, Unit 1, '
1 Docket No.50-44C)
COMMONWEALTH EDISON CO.- (Dresden Nuclear Power Plant, Units 2 and 3 Docket hos. #
50-237 and 50-249), (Quad Cities Nuclear Power Plant, Units 1 and 2 Docket Nos.
50-254 and 50-265), (LaSalle County Station, Units-1 and 2. Docket Nos. 50-373 and 50-374)
CONSUMERS POWER CO.-(Big Rock Point, Docket No. 50-155)
DETROIT EDISON CO. (Fermi Unit 2 Docket No. 50-341)
GENERAL PUBLIC UTILITIES (Oyster Creek Station, Docket No. 50-219)
GEORGIA POWi.R CO. (Hatch Nuclear Power Plant, Units 1 and 2, Docket Nos. 50 321 and 50-366)
GULF STATES UTILITIES CO. (River Bend Station, Docket No. 50-458)
ILLINDIS POWER CO. (Clinton Nuclear Power Plant, Docket No. 50-461)
IOWA ELECTRIC LIGHT & POWER CO. (Duane Arnold Nuclear Power Plant, Docket No. 50-331)
LONG ISLAND LIGHTING CO. (Shoreham Nuclear Power Plant, Docket No. 5D-322)
MISSISSIPPI POWER A LIGHT C0. (Grand Gulf Nuclear Station, Docket No. 50-416)
NEBRASKA PUBLIC POWER DISTRICT (Cooper Station, Docket No. 50-298)
NIAGARA MOHAWK POWER CORP. (Nine Mile Point, Units 1 and 2, Docket Nos. 50-220 and50-410)
NORTHEAST UTILITIES (Millstone Unit 1, Docket No. 50-245) g j
g
f.C: -E:.t. STA E5 00WEk CC. (Monticelle fiuclear Power Flant, 00cket No. 50-263)
FEN?,5 % GN:A F0WE; & LIGHT CO. (Susquehanna Steam Electric Station, Units 1 and 2' Cc:ke: f.cs 50-3E7 and 50-385)
FF:LACELPH: A ELECTRIC CO. (Peach Botton Nuclear Station, Units 2 and 3, Jocket Nos.
EC-277 and 50-278), (Limerick Nuclear Power Plant, Unit 1, Docket No. 50-352) l F0WEF AUTHOF.*TY CF THE STATE OF NEW YORK (James A. Fitzpatrick Station, Occket No. 5C-333)
FUELIC SERVICE ELECTE:C 1 GAS CO. (Hope Creek Generating Station, Docket No. 50-254)
, TENNESSEE VALLE) AUTFOR:~Y (Erowns Ferry t'uclear Station, Units 1, 2, and 3, Docket hos. 50-259, 50-2EC, and 50-296)
I YERM0t.T i AfdEE NUCLEAE F0WER CORP. (Vermont Yankee Nuclear Power Plant, Dccket No. EC-271)
W:5":f;37Ch FL5;:0 FLER SUFFLY SYSTEM (Wf1F Unit 2, Docket No. 50-397) a L:FECTOF'S CECISIOh UNDER 10 CFR 2.206 1.
INTRODUCTION Cn July 22, 1988, Ms. Susan Hiatt, on behalf of Ohio Citizens for Responsible Energy, Inc., (Petitioner) filed a Petition in accordance with 10 CFR 2.2C6 with the f;uclear Regulatory Comission (NRC). The petition was referred to the Directer, Dffice of Nuclear Reactor Regulatior. (NRR) for consideration.
The Petition asked the Director, NRR, to take imediate action to relieve alleged undue risks to the public health and safety posed by the thermal-hydraulic instability of boiling-water reactors (BWRs), as revealed by the power oscil-lation event at LaSalle Unit 2 on t< arch, 91988 (LaSalle Event). The Petitioner specifically recuested the NRC to order all BWR licensees to (1) place their reactors in cold shutdown, (2) develop and implement specified operating cr::edures reia:ir; to the thermal-hydraulic instability issues, (3) damorstrate
7,
]
- 3..
that certain specified training has been provided relating te these procedures,
rl demerstrate the capability of instrumentation related to power oscillations, '
(5) cevelcp sirnulators capable of modeling power oscillations similar to those occurring at LaSalle as well as out-of-phase power oscillations, (5) report to the NRC all past and future incidents in which recirculation pumps have tripped off, (7) submit to the NRC justification for continued operation of BWRs, and (S) submit a repert to the NRC within 1 year demonstrating compliance with Criterion 12 given in 20 CFR Fart 50, Appendix A (GDC-12)I.
In addition, the Petitier er requested the Comission to reopen Generic Issues 8-19 and B-59, to reopen the Anticipated Transients Without Scram (ATWS) rulemaking proceedir.g, anc te rece-sicer the use of the end.cf-cycle recirculation pump trip on SWRs.
Ms. Hiatt alleged as grounds for the Pet'ition that the LaSalle Event has seriets safety it;11 cations fer all BWRs and that the Nuclear Regulatory Cerrission (NEC) has f ailed to take appropriate regulatory action in response to the LaSalle Event.
In the Petition, Ms. Hiatt cites the following postulated 1
safety implications, some of which had been previously identified in several referenced documents attached to the Petition:
(1) decay ratios determined by licensing calculations are not reliable indicators of core stability (Attachment 2 to Petition) and design analyses of the reactor cannot be relied upon to ensure that oscillations are not possible in BWRs; (2) The General Electric (GE) Company's guidance for operations provided in Service Information Letter (SIL) 380, Revision 1, is inadequate to ensure compliance with GCC-12 ( Attachment 4 to Petition); and (3) SWR plant instrumentation may l
10 CFR Part 50, Appendix A, Criterion 12, " Suppression of Re:ctor Power Oscillations," states that: "The reactor core and associated coolant, control, and prctectier. systers shall be designed to assure that power oscil16tions which can result ir. conditions exceeding specified acceptable fuel desigt, limits are not possible er can be reliably and readily detected and suppressed.'
i
O net detect power esc 111ations if they occur out of phase or too rapidly (Attachments 1 and 4 to Petition). Ms. Hiatt then asserts that (1) given the implications of the LaSalle Event, the actions requested of BWR licensees in NRC Bulletin No. 88-07 are insufficient, (2) most, if not all BWRs, are in a stateofnoncompliancewithGDC-12,and(3)theNRCmusttakeaggressive enforcement action to protect the health and safety of the public.
On August 26, 1988, I acknowledged receipt of the Petition.
I informed Ms. Hiatt that (1) her request for isinediate relief was denied because the allegations that formed the basis for the Petition did not reveal any new operational safety issues that posed an isinediate safety concern for continued BWR operation, G ) the Petition would be treated under 10 CFR 2.206 of the Commission's regulations, and (3) appropriate action would be taken within a reasonable amount of time.
For reasons discussed below, the Petition is denied.
Ms. Hiatt's request to reopen rulemaking proceedings regarding ATWS is being treatec separately as a petition for rulemaking under 10 CFR 2.802 of the Consnission's regulations.
II.
BACXGROUND The LaSalle nuclear power station, operated by the Commonwealth Edison Company (CECO), is a two-unit site located 11 elles southeast of Ottawa, Illinois. Both units utilize General Electric-designed BWR/5 reactors with containments of the Mark II design.
On March 9, 1988, LaSalle Unit 2 underwent a dual' recirculation pump trip event that resulted in a loss of forced circulation cooling, a reduction in l
l l
- - -- - ---- -- A
\\
~
reat:cr cene, ard a decrease in reactor inlet feedwater temperature.
A;crcx1mateb 5 minutes after the recirculation pump trip, with the reactor being cocied via natural circulation, operators observed that the average power range monitor (ApRM) indications were oscillating between 25 and 50 percent power (25 percent peak to peak) every 2 to 3 seconds. At the same tire, the local pc er range monitor (LPRM) downscale alarms began to annunciate and clear, ircitating that power was oscillating about the downscale alarm setpoint. During this period, the operators recognized that they were operating in a regier c' cere instability.
They attempted to restart a recirculation purp ir cree-tc ircrease flow te prevent instability, but this action was unsuccessful as all cf the pump start permissive conditions had not been satisfied.
(Ferrissives are protective features designed to inhibit start-up of ecuipment wter certain specified conditions critical to proper functioning of tre ecui; rent are not within specified limits). Approximately 7 minutes af ter the recirculation pump trip, as operators were preparing to perform a manual scrat, the reactor scrarred automatically because of high neutron flux in the reactor.
(A reacter scram involves rapid insertion of shutdown and control rods by either manual or automatic actuation of the reactor protection system).
The scram shut the reactor down, and recovery from the scram proceeded normally.
On March 16, 1985, after receiving additional information from the licensee concerning the event, the NRC dispatched an augmented inspection team (AIT) to the site.
The AIT completed its inspection on March 24, 1988, and issued its inspection report on May 6, 1988.
The AIT concluded that (1) fuel l
design limits had net been exceeded during the transient, and fuel damage had I
notoccurred;(2)plantequipmentfunctionedasdesigned;and(3) operator ac icrs caring the event were within the bouncs of their procedures and training, j
1 4
I- ___-_-__-_ _-__-
q
.?
l 6
l t.: tre ;ec:ecures ard training program themselves were inadequate. The A]T also icertifiec a nurter o# generic technical concerns and recommended that they be torsicerec further by the staff.
On June 8,1988, the NRC Office for Analysis and Evaluation of Operational Cata (AEOC) issued a special report documenting its concerns regarding the power oscillation event at LaSalle 2 and its recommendations for follw-up action.
A respense to tre rec:rrercations was provided to AEOD by NRR on June 24, 1988.
On Jure 15, 1956, following completion of its evaluation of the March 9, 1988, event et LeSa11e, tre M: issued Bulletin No. 88-07 to holders of operating licenses ar.c cerstro:tice perr'ts for BWEs. The bulletin requested that recipients take a: tier te ers -e that ace:uate operating procedures and instrumentation are avail-atle and adecuate operator training is provided to prevent the occurrence of power j
escillatiers during all medes of BWR operation.
The h.11etin re;uired that recipients confirm by letter to the NRC that the requestec actiers were completed and implemented. All confirmation letters have been received and reviewed. They indicate that.
1.
All EWE licensees have procedures in place to detect and suppress instability regardless of the value of previously calculated decay ratios; 2.
All licensed reactor operators and shift technical advisors were briefed regarding the LaSalle Event within 15 days following receipt of the bulletin, or before resuming shift duties if they had been unavailable during the 15 day period; 2.
All action to modify operating procedures and the operator training prograr with respect to detection and suppression of potential rea:ter irstatilities had been completed or would be completed before
-. _ _ _ - ------- _ il
\\...
7 startc; frer the current outage and, in a few cases, no later than Ce:er:er 15, 1988; and, z.
All licensees have confirmed that instrumentation relied upcn by plant operators to execute operating procedures 15-adequate based on an assessrert by the equipment vendor (GE) and a_ review of any modifi-cations made to equipment since installation.
The staff has te;un to audit licensee responses to the bulletin in more detail.
The audits will centinue ever the next year.
In hoverter 1965, General Electric Company (GE), working with the BWR Owners' G cu: (FWECG}, issuec a letter entitled
- Interim Recommendations for Stability Acticr.s' te the EWR licensees.
The interim reconinendations are based en the results of a generic evaluation of power oscillations performed for the EWRC3 at the request of the NRC staff. This evaluation has indicated 2
that when'regioral power oscillations become detectable on the average power targe monitors, the safety margin with respect to the plant minimum critical power ratio (MCFR) may be insufficient under some operating conditions to ensure that operator actien in response to APRM signals would' prevent violation of the MCPR safety limit. The interim. recommendations include explicit restrictions and modified operator actions to ensure that operation in the vulnerable power / flow operating regime is avoided. The recommendations were reviewed by the NRC staff and have been found acceptable for those plants which have effective automatic scram protection for regional oscillations. For plants 2 Regional oscillations are ones in which power oscillates only in distinct regions o' the reactor core, as opposed to a core. wide oscillation, in which P;aer es:iliates throughcut the core as war the case in the LaSalle Event.
l
4 g.
' w r. i c t. de net have effective automatic scram protection for regional oscillations, tre staf f telleses that the interim recommendations may not provide sufficient, reliable pretenion.
Consequently, the staff has requested that licensees irplement the interim recommendations, and if appropriate, implement additional H
I actions which compensate for the lack of automatic scram protection for regional l
i oscillations.
The staff's request is contained in Supplement I to NRC Bulletin SS-C7 which is discussed in the ntxt paragraph.
Or Decenter 3C, 19EE, the NRC issued Supplement I to NRC Bulletin 88-07.
The st;;;e er prosides addressees with new information concerning power estillatiers in EWRs and recuests that they take specified actions to ensure that the safety lirit for the plant minimum critical power ratio (MCFR) is not i
viciated as a result of regional power oscillations.
The supplement is an outgrowth c' generic evaluations of power oscillations performed by the BWROG at the NP.C staff's request and the staff's independent study of regional power oscillations. The preliminary results of these evaluations indicate that when 1
regional power esci11ations become detectable on the average power range monitors, the MCFR safety targin may be insufficient under some operating conditions to ensure that manual actions taken in response to APRM signals would prevent 3
violation of the MCPR safety limit. Licensees were requested to take the following actions:
3 The supplement is not applicable to Big Rock Point (00cket No. 50-155) because of cricue design features and because existing operating limitations enforced by technical specifications address the stability concerns which are the subject of the supplement.
-____________________________L
c (1) u ttin 3C cays of receipt of the supplement, all BWR licensees should inplerent the GE intsrim stability recommendations described in the GE letter entitled " Interim Recommendations for Stability Actions". However, for these plants that do not have effective automatic scram protection in the ever.t of regional oscillations, a manual scram should be initiated under all operating conditions when two recirculation pumps trip (or "no pumps operating") with the reactor in the RUN mode.
(2) The boundaries of Regions A, B, and C shown in Figure 1 of the GE recom-rrencations were derived for those BWRs using NRC approved GE fuel. For BWRs using fuel supplied by other vendors, these regions should be adopted in principle, but the power / flow boundaries should be based on existing beundaries that have been previously approved by the NRC. For proposed new fuel designs, the stability boundaries should be reevaluated and justifiec based on any applicable operating experience, calculated changes ir, ccre decay ratio using NRC approved methodology, and/or core decay ratio measurements.
There should be a high degree of assurance that instabil-ities will net occur under any circumstances of operation in Region C.
(2) The GE interim recommendations are ambiguous with respect to permissible conditions for entry of Regions B and C.
Although the recommendations state that intentional operation in Region B is not permitted and operation in Region C is permitted only for purpose of fuel conditioning durinc rod withcrawal startup operations, intentional entry into Region B or C is also allowable in situations where rod insertion or a flow increase is required by procedures to exit Regions A and B after unin-tertional entry.
Licensees should ensure that the procedures and training employec for implementation of these recommendations avoid any similar artiguity which could lead to operator confusion.
Fursuant to 10 CFR SC.54(f), licensees are required to advise the NRC by letter within EC days of receipt of the supplement whether the requested actions have been completed and implemented.
The staff will evaluate the responses and the results of studies which are continuing over the next several months to determine whether any additional action by the staff is necessary.
[.
. il I:1.
CISCUSSION Py staff arc ! have considered the safety implications identified in the Fetition and the s;ecific relief requested and have done so in light of the most recent cata availatie to the staff from the BWROG and staff consultants. Our 4
evaluatior follows.
A.
Eases for c :uest e
1.
Febetility of Decay Ratio for predicting Stability Decay retic in a reactor is a measure of the response of the neutron flux to 6 chance er perturbation. As such, it is a convenient measure of the relative statility c' a reactor core.
A decay ratio of less than 1.0 indicates inherent statility it: that the response to a perturbation will decay to the steady state value. A decay ratio equal to 1.0 represents the special condition when the response to a perturbation will be continuing oscillations of constant magnitude termed lir.it cycles. A decay ratio greater than 1.0 indicates an unstable condition in that the response to the perturbation diverges in a linear system.
In a BWR, which is a non-linear system, decay ratios greater than 1.0 are indicative of larger amplitude limit cycle oscillations. Predictive methods developed by General Electric for deterinining BWR decay ratios were approved by the NRC with the provision that a 20 percent uncertainty be applied conservatively to the result.
Calculated core decay ratios of less than 0.80 (i.e.,,1.0 minus an uncertainty of.2) by GE retnces were approved as acceptable evidence of core stability anc cer;1iance witt GDC-12.
l.
+
J T*e c-edicte: cecay ratio for the LaSalle Unit 2 reactor was 0.60.
he ever,.la ;e esci11atier.s were observed during the LaSalle Event that indicate tnat actual cece) retic was greater than 1.0.
Consequently, the uncertainty in the predictive method was significantly larger than expected, that is at least 4C percent versus 20 percent.
The larger-than-expected calculational uncertainty has since been attributed tc ar. ir.ade:,, ate represertatier, cf actual reactor operating conditions in the LaSalle calculation <a1 model.
In light of this potential for error, the staff has cor:1udec trat it will rc longer accept predictive calculations of core decay ratio as ases fer cercestrating compliance with GDC-12.
Ir,crder #cr a licensee to satisfy GDC-12 with respect to core-wide power esci11ations, the staff's position is that each BWR unit must have the necessary c;eratirg lirritaticns, response procedures, and operator training program to readily and reliatly cetect and suppress core-wide power oscillations regardless of caleviatec cecay ratio. The staff has communicated this position to licensees in NRC Bulletin No. 88-07. As discussed above, all licensees have now responded to Bulletin No. SS-C' and have indicated that they have the necessary proceduret and operator training program to readily and reliably detect and suppress core-wide power oscillations regardless of calculated decay ratios.
4 2.
Adequacy of Procedural Guidance from GE (Service Information j
Letter 380, Revision 1)
The Gerera'. Electric company issuec Service Information Letter (SIL) 380, 1
l Revisier 1 to its custorers on February 10, 1984 The letter reflected new L
tec r:cai ir#crratier re;arcin; EWF stability and provided new guidance to EWR
)
.9 J
,4 12 l
eceraters #ce cetecting and suppressing neutron flux oscillations. The letter supersecec the pre.,ously issued SIL 380.
The tJ: staff reviewed SIL 380, Revision 1, as part of its action'to resolve Generic Issue E-19, "BWR Thermal-Hydraulic Stability." On the basis of the staff's review and that of its contractor, Oak Ridge National Laboratory, the g
staff concluded that " operating limitations which provide for the detection and sup;ressior. cf ' lux oscillations in operating regions of potential instability, consistent with the recommendations of General Electric SIL 380 (Rev.1), are acceotatle tc cetonstrate cor; liar.ce with GDC-10 and GDC-12 for cores loaded with a;;revec CE fuel cesiens." The basis for this conclusion was the result cf a technical e,abetion that indicated that if properly implemented, the recommendations contained in the SIL were sufficient to readily and reliably cetect and sL; press lirit cycle oscillations.#
It is im;criant to note that operating procedures consistent with GE SIL 380, Revision I were not in place at LaSalle Unit 2 at the time of the March 9, 1988 incident. Cor.sequently, the response and performance of reactor operators durinc the LaSalle Event does not reflect on the adequacy of the SIL re corrnenda tions.
The flRC staff continues to endorse the general operational guidance given j
'[
in GE SIL 380, Revision 1 and believes that if properly implemented, it is l
sufficient to identify and terminate core-wide limit cycle oscillations. However, 4 tJC Pererandum ar.d attachments from Harcld R. Denton to Victor Stello, cated Pay 21,-19E5.
li
j i
r:
l 13 es ciscusse: pres iously in section II of this document, supplementary procedural a: tier.s are.necessary to ensure that the safety limit for the plant minimum critical power ra:ic is not viciated as a result of regional power esci11ations.
~.
Acecuacy of Flar,t Instrumentation 3r. Bus desigred by GE, the neutron monitoring system (NMS) is used to monitor tre core fer r,eutrer. flux oscillations. The NMS uses incore detectors to monitor rectrcr 'ic) frer star:c: through full-power operation and is a safety-related syster.
Tre fJ" staff reviews the design of the NMS as part of its norinal licensing review.
Ir gereral, the staff considers the NMS to be adequate for implementation cf the guicelires provicec in GE SIL 380, Revision 1.
However, during follow-up review cf the LaSalle Event the f,RC augmented inspection team identified sone time respense and filtering characteristics of the NMS inst'ruments in LaSalle L' nit I that they were concerned about. The AIT also expressed concern about' the ability of the AFRMs to properly detect regional oscillations which cause LPRM signals to oscillate out-of-phase. Because of these concerns, j
the staff requested, in i:RC Bulletin No. 88-07 and in meetings with the BWROG, that licensees verify the adequacy of the instrumentation that is relied upon by operators within their procedures.
In response to Bulletin 88-07, all licensees have evaluated their irstrurer.tatier, with regarc to time response and filtering characteristics and
.c
-la-rave irdicate: trat instrumentation relied upon by plant operators to execute operatir; procecures is acetuate.
The EWROG and the NRC staff have
'inceper.cently evaluatec the ability of NMS instrumentation to properly detect recieral oscillations which occur as asymmetric out-of-phase oscillations.
The results c' these evaluations are discussed below.
Power oscillations with an amplitude and phase that vary spatially in the reacter are terred regiona' estillatiers, and usually occur as asymmetric out-of-phase escillatiers. These oscillations are difficult to monitor accurately 1
witt aserage power range instrur,ents in the NMS but can be detected with local power rarge irst vrents.
The results of generic evaluations of power oscillations perferred by GE for the BWR owners group (BWROG) at the request cf the NR: staff and the staff's independent evaluation have indicated that when regional power esci11ations become detectable on the APRMs, the safety rar;in witn respect to the plant minimum critical power ratio (MCPR) may be insufficient uncer sore operating conditions to ensure that operator action ir response to APRt' signals would prevent violation of the MCPR safety limit.
In light of this GE issued interim recommendations to BWR licensees which include explicit restrictiers on reactor power level and coolant flowrate, and actions for plant operators to take if unacceptable power / flow operating regimes are entered unintentionally. The interim recommendations were reviewed by the NRC staff and found acceptable for those plants which have effective automatic scram protection for regional oscillations.
For plants which do not have effective automatic scrar protection for regional oscillations, the staff believes that the interie reconrencations rey not provide sufficient, reliatie protection.
Consequently, the sta#f has recuested that licensees implement the interim reccmrendatiers, anc if appropriate, implement additional actions which i
l.
c..
4 p
~
1 1 i l
I cc cersste 'cr t*e lack cf auto atic scram protection for regional oscillations.
te staff's recuest is cor,tained in Supplement I to NRC Bulletin 88-07 which 1
-l was ciscussed previcusly in the section II. of this document. The staff believes i
1 that implementation of the requests in NRC Bulletin 88-07 and Supplement I to the bulletin will ensure continued safe plant operation in the interim until long-term ccrrective actions are developed and put in place. The NRC staff will certitue to wc"A with the SnECG to develop long-term corrective actions.
The sta#f expects to issue ancther generic communication within 12 to 24 months that wil; ;*c. ice guidance for long-term resolution of this stability issue.
4 Safety Sigr.ificance of Power Oscillations i
Power oscillations in EWRs are not considered to be a serious generic safety c ncern tecause oscillations can be detected and suppressed. Tests and operatirg ex;erience (LaSalle Event) indicate that core-wide power oscillations can be terminated marually in a timely fashion by control room operators or ultimately t.) automatic action of the high-power level trip function in the reactor protection system.
Asymmetric out-of-phase oscillations are unlikely because of restrictions on reactor operating conditions. Moreover, procedures specified in Supplement I to NRC Bulletin 88-07 ensure that such esci11ations would be suppressed quickly with an anticipatory reactor scram initiated manually by a reactor operator.
- 1..
y, p
' l E.
Cet ititrer's Recuest l
1.
Orcer All EhR Licensees To Place Their Reactors in Cold Shutdown i
As described above, the NRC issued Bulletin 'o. 88-07 in response to the N
L aSal'.e ever.t.
As indicated by their responses to Bulletin No. 88-07, all.
BLE litersees have developed and implemented procedures to detect and sup-press core-wide pcwer esci11ations.
Consequently, no BWR licensee now relies cr a calculated decay ratio to demonstrate compliance with GDC-12.
As already ex;',ained, Supplement I to Bulletin No. 86-07 specified edditional procecures to deal with regional power oscillations. The recommendations of Su;;1erert I are currer.tly being implemented. In light of the relatively shcrt period for implementation (60 days), and existing restrictions on reactor cperating conditions that minimize the probability of regional oscillatier.s, the staff has concluded that continued operation of all 8WRs while licensees are implementing the recommendations of Supplement 1 is acceptable.
In summary, based on our review of the generic implications of the LaSalle Event to date, we have not identified any operational safety concerns nor instances cf regulatory non-compliance which warrant a shutdown of boiling water reactors.
Consequently, your request is denied.
1
?
+, :
.a
- f. i.
i g-1 l
l
~.17 L
1 2.
Order M1 EW:.. Licensees to Develop and Implement Specified Frctec ves.-
Tris recuest is der.ied for the following reasons:
)
j (a) The NRC staff currently believes that procedural guidance provided tc licensees in SIL 360, Revision I for detecting and suppressing power esti11ations is adequate for mitigating core-wide oscillations.
9 (t ' Tre N staff has determined that explicit procedures different from
.tr.cse specified by the Petitioner are necessary to control regional poveer estillations and ensure continued plant operation in a:corcance with GDC 12.
The staff has specified the necessary procedures in Surplemer,t I to NRC Bulletin 88-07 and requested that licensees implement the specified procedures within 30 days of receipt c' the supplement.
5 Petitioner requests implementation of the following specific procedures:
(a) Immediately insert control rods to below t'ie 80% rod line following reduction or loss of recirculation flow or otter transients which result in entry into potentially unstable regions of the power / flow map; (b) Increase recirculation flow during routine reactor startups and insert some control rods prior to reducing recirculation flow below 50% during shutdowns to avoid operation ir peter.tially unstable areas of the power / flow map; (c) imediately scram the reacter if (a) or (b) above are not successful in preventing and suppressing estillations.
The licensees shall submit these procedures to the NRC for review and approval.
._-..________________---________L
s.
..f
.0
-1B-t e
The contents of Supplement 1 to N'.C Bulletin 88-07, including the specifiec procecures, are discussed in section II of this document.
The staff has judged that continued plant operation during the 30 day
!=
implementation period is acceptable based on the low likelihood of a regier,al oscillation in the relatively short period of 30 days.
3.
Order all BWR Litersees To Demonstrate That Certain Training Related to tr.e Specifisc Frocedures Has Been Provided-This re:.est is denied for the following reasons:
(a) The respor.ses to NRC Bulletin Nc. 88-07 indicate that all licensed reactor operators ene shift t;chnical advisors perferning shift cuties at BWRs were briefed thoroughly regarding the LaSalle Event within 15 tays of receipt of NRC Bulletin No. 88-07 or soon thereafter.
(t) The respor.ses to NRC Bulletin No. 88-07 indicate that all BWR licensees have confirmed the adequacy of their existing operator training program regarding detection and suppression of power i
' oscillations or have made the program modifications necessary l
to properly address this subject and accommodate changes in procedures in response to Supplement l'to the bulletin.
i e
___-__._m________-___--
1 19 4
Creer All EWR Licensees To Demonstrate the Capability of Instrumentation Feietec to Power Os:i11ations This recues: 15 denied for the following reasons:
( a,' The NEC :!taff considers the neutron monitoring system designed for EWRs by GE to be adequate for detecting core-wide power oscillations ir. Euis.
(t:
Cr, tr.e tasis c# responses to NRC Bulletin No. 88-07, the NRC staff telieves that til licensees have confirmed that the response anc filtering characteristics of instrumentation relied upon ty cperators Ic execute operating procedures are acceptable.
(c)
Implementation of operating procedures specified in Supplement I to NRC Eulletin 88-07 will compensate for inability of APRMs to properly detect regional oscillations.
5.
Order All BWR Licensees To Develop Simulators Capable of Modeling Power Oscillations Similar to Those Occurring at LaSalle and Out-of-Phase Oscillations l
. i
--______--_-______-___-_______-_-__-___L
v
+
W is rec.;est is denied for the following reason:
(a). Current tiRC regulations, that is, 10 CFR 555.45(b), in conjunction with NRC Regulatory Guide 1.149 and NUREG-1258, s
already recuire utilities to have a simulation facility capable i
of modeling the effects of loss of forced reactor coolant flow and to certify the simulation facility for use in etereter licensing examination after May 26, 1991. However, although simulator training for control of power oscillations wi'1 ir; rove an operator's ability to detect and suppress oscillations in a timely fashion, non-simulation based training can be fashioned which is sufficient to address stability cencerns.
Consequently, the staff concludes that training programs now in place, including improvements made in response
~
to NRC Sulletin 88-07, are adequate in the interim until the enhancements of 10 CFR 555.45(b) take full effect in 1991.
6.
Order All BWR Licensees To Report to the NRC Regarding all Future and Past Incidents in which Recirculation Pumps have Tripped Off or that Involved Power Oscillations.
l l
L j
. ~.
i l
, 1 l
l l
l It's' e;uest is deried for the following reasons:
(a' Esistire NR: regulations, that is, 10 CFR 550.72 and 10 CFR 550.71, a* ready recuire that significant events involving recirculation pump trips or power esci11ations be reported to the Commission. Such eser.ts are these ir. which the pump trips or oscillations lead to (a) coe;1etier, of any nuclear plant shutdown required by the plant's tec*rical specifications; or, (b) any operation or condition prohibited ty the ;1 art's technica-specifications; or, (c) the plant being in a cercitier. r,ct covered by the plant's operating and emergency procedures, or (d) ary event or condition that resulted in an unplanned manual or autcratic actuation of any engineered safety feature, including the reacter protection system.
Petitioner demonstrates no basis for l
requirir.g repetition of reports already required by 150.72 and
!!C.73.
(b) Since the accident at Three Mile Island, Unit 2 in 1979, programs have been developed and implemented in several NRC offices to 2
systematically review and evaluate operating reactor event reports. Such programs include Analysis and Evaluation of Operational Data (AEOD), Operating Reactors Assessment and Events Analysis (fJR) and the Resident Inspector program (NRC Regional Offices). These reviews have been performed to ensure prompt response tc accidents, to identify significant precursor events and
\\1
- -. - -.i
7 4
-22 tc icertify adverse trends and patterns in operating experience, irciucir; ary associatec with B,lR instability. The staff considers L
these past reviews of licensee event reports to have been adequate.
The Petiticn gives no basis to re-examine these reports and the staff concluces that action to collect and review past event reports is unnece s sa ry.
- 7. Reepen Generic Issue 519, "BWR Thermal. Hydraulic Stability" Tris recuest is cenied because a genfric reassessment of BWR stability is net necessary dr creer for the staff to specify criteria licensees must meet to te in coe;1iarce with existing regulations.
M: staf' action on Generic Issue B-19 culminated in the identification c' twc acceptable methods by which licensees could show compliance with GDC-10 ar.d GDC-12. Licensees could either (1) show that thermal-hydraulic instabilities are net possible by design by calculating acceptably low decay. ratics with analytical methods approved by the staff, or (2) show that proper capabilities for detection and suppression of oscillations are embodied in plant operating procedures and operating limits. As discussed in section A.I. of this Decision, the staff has concluded that in light of the LaSalle Event, use of a calculated I
decay ratio to demonstrate compliance with general design criteria is no longer acceptable and that all BUR licensees must show that proper detection and suppression capabilities exist at their plants, that,is, method 2 listed previous ly. Because the staff concludes that the implementation of method 2 listed above cortinues to be a valid means for complying with G0t 12, method 2 remains a valic resolution of Generic Issue B-19. Consequently, repetition of tre generic issse resciution process for *ssue E-19 is unnecessary.
L.
.d
.(
a h
[
8.
Reopen Generic Issue B-59, "Part Loop Operation in PWRs and BWRs" This request is denied because the LaSalle Event has not revealed any deficiency in the technical resolution of Generic Issue B-59.
In resolving Generic Issue B-59 for BWRs, the staff evaluated the accept-ability of operating the reactor for electricity production at reduced power
'with only one of two recirculation loops in operation (i.e. at a reduced coolantflowrate). The results of the evaluation were that stable single loop operation is achievable and acceptable with specified operating limits and procedures for avoiding as well as detecting and suppressing power oscillations that may arise (e.g.,
if perhaps t'.c operating recirculation pump tripped). In the LaSalle Event, instability arose following inadvertent trip of both recirculation pumps when the reactor operated with no recirculation loops in operation. Power operation with both recirculation loops inoperable is prohibited by each license for operation of a BWR. The LaSalle Event reaffirms the necessity for prohibiting operation with no recirculation loops in operation. However, the LaSalle Event does not invalidate the technical findings from the review of Generic Issue B-59.
9.
Reopen Rulemaking Proceedings Regarding Anticipated Transients Without Scram In the acknowledgement letter sent to Petitioner on August 26, 1988, I included this request among those to be considered pursuant to 10 CFR 2.206.
I have subsequently determined, however, that this request is more properly treated as a petition for rulemaking under 10 CFR 2.802. As such, it has been referred to the NRC Office of Research for appropriate action. However, it is important to i
l-
-____-____-__--_______-________-___L
note that both the NRC and BWR Owners Group (BWROG) currently have programs in which analyses cf ATWS conditions are being conducted. These analyses treat large amplitude power oscillations with state-of-the-art analytical methods. The results of these analyses to date confirm the technical bases for the current l
ATWS rule. Consequently, at this tim, the NRC staff sees no basis for recom-mending that the Connission reopen rulamaking proceedings regarding ATWS.
If, however, the staff finds evidence which contradicts the assumptions and results of previous ATWS analyses from either the information you provided in support of the request or new information from ongoing NRC and BWROG programs, it may then te appropriate for the Commission to reconsider the current ATWS rule.
- 20. Reconsider Use cf the End-of-Cycle Recirculation Pump Trip on BWRs l
The end-of-cycle recirculation pump trip (EOC-RPT) is part of the reactor protection system and is an essential safety supplement to the reactor trip. The EOC-RPT reduces reactor coolant flowrate to provide additional negative reactivity for mitigation of events in which the reactor coolant system is pressurized rapidly.
The additional negative reactivity from the EOC-RPT is needed primarily at the end l
of the cycle to compensate for (1) changes in reactor power distribution over the 1
cycle that have reduced thermal margin and (2) a decrease in the rate of negative reactivity insertion during reactor seram. The two events for which the E0C-RPT protectivefeaturewillfunctionareclosureoftheti.rbinestopvalvesandfast l
l closure of the turbine control valves.
In both cases the EOC-RPT is accompanied g
1 by an anticipatory scram of the reactor that is initiated by the same signals that initiate the EOC-RPT.
l l
l
[..:
V e
..pg.
II.
Renire Licensees To Submit Justification For Continued Operation in Light
.of the Issues.F.ais?d in the Petition.
in NRC Bulletin 87-07 and Supplernent 1 to that bulletin, the NRC Staff specified actions licensees should take to ensure continued safe operation ar.d compliance with the Comission's regulations. All licensees have confirmed, under oath and affirmation, that (1) all necessary actions requested in NRC e
Bulletin 87-07 have been completed and, (2) that full documentation of the ection taker, is available for inspection by the NRC. Licensees are also required tc aevise the NRC by letter, within 60 days of receipt of Supplement I to the tulletin, whether actions requested in the supplement have been completed anc implemented.
The staff considers respcnses to both the bulletin and the supplement, which ere acceptable to the steff, to be edequate justification en the part of licer. sees for continued operation. Consequently, yeur request is denied.
- 12. Order All EWR Licensees to Submit a Report to the NRC Within One Year Derenstrating Compliance with Criterion 12 Given in 10 CFR Part 50, *.ppendix A (GDC 12)
As indicated previously in paragraph A.1., the NRC staff's position regarding corpliance with GDC-12 is that, regardless of the magnitude of the calculated decay ratio, each BWR licensee should have in place the necessary
26-operating limitations, response procedures, and operator training program that q
perrit plant operators to identify and terminate limit cycle oscillations.
4 The staff's position was comu.micated to licensees in NRC Bulletin No. 88-07, through reetings with the BWROG and in Supplement I to !!P.C Bulletin 88-07. The staff believes that actions licensees are expected to take in response to NRC Bulletin 86 07 are sufficient to ensure compliance with GDC-12 for core-wide oscillations.
However, if plant inspections reveal that actions taken by
' licensees are inadequate, plant-specific actions would be pursued at that time.
6lith respect tc regional oscillations, procedures specified in Supplement 1 to tJC Bulle.tir 25-07 ensure that such escillatiens would be suppressed quickly with an participatory reactor scram initiated ranually bi a reactor operator. As discussec previously, the steff believes that impleinentation of these procedures will ensure continued safe plant operation in the interim until long-term ccrrective ections are developed and put in place.
~
IV. CONCLUSION The Petitioner seeks the institution of a show-cause proceeding pursuant to 10 CFR 2.202 to modify or revoke the operating license of all SWR facilities.
The institution of proceedings pursuant to 10 CFR 2.202 is appropriate only where substantial health and safety issues have been raised. See Consolidated Edison Company of New York (Incian Point, Units 1, 2, and 3), CL1-75-6, 2 NRC 173 (1975) and Washincton Public Power System (WPPS Nuclear Project No. 2), DD-84-7,
d
-1
.,e 19 NR 899, 923 (1954). This is the dandard that I have applied to the concerns raisec by the Petitioner in this decision to deters 11ne whether enforcement action is warranted, l
For the reasons discussed above, I conclude that no substantial health and safety issues have been raised by the Petitioner. Accordingly, the Petitioner's request for action pursuant to 10 CFR 2.206 is denied. As provided
)
in 10 CFR 2.206(c), a copy of this Decision will be filed with the Secretary of the Comission for the Comission's review.
j FOR THE NUCLEAR REGULATORY COMMISSION
, 3 0 -- b r
Thomes E. Murley, Director Office of Nuclear Reactor Regulation I
'ed at Rockville, Maryland, t.. i s 27th cay of April 1989.
i f
l
- 1'?
ENCLOSURE 3 NUCLEAR REGULATORY COMMIS$10N DOCKET NO. 50-293, et al.*
BOSTON EDISON COMPANY, et al.*
.(PilgrimNuclearPowerStation,etal.)*
ISSUANCE OF DIRECTOR'S DECISION UNDER'10 CFR 2.206 Notice is hereby given that the Director, Office of Nuclear Reactor Regulation (NRR), has issued a Director's Decision concerning a Petition dated July'22, 1988, filed by Ms. Susan Hiatt, on behalf of Ohio Citizens for i
Responsible Energy Inc. The Petition asked the Director, NRR, to take immediate action to relieve what the Petitioner alleged to be undue risks to the public health and safety posed by the thermal-hydraulic instability of boiling-water rea'ctors (BWRs)', as revealed by the power oscillation event at LaSalleUnit2onMarch9,1988(LaSalleEvent). The specific relief requested was to order all BWR licensees to (1) place their reactors in cold shutdown, (2) develop and implement specified procedures relating to the thermal-hydraulic instability ir. sues, (3) demonstrate that certain specified training has been I
y provided relating to these procedures, (4) demonstrate the capability of instru-mentationrelatedtopoweresci11ations,(5)developsimulatortcapableofmodeling.
power oscillations similar to those occurring at LaSalle and out-of-phase power oscillations, (6) report to the NRC regarding all past and future incidents in which recirculation pumps have tripped off, (7) submit to the NRC justification for continued operation of BWRs, and (8) submit a report 'to the NRC within one year demonstrating compliance with criterion 12 given in,10 CFR Part 50, AppendixA(GDC-12).
In addition, the Conrnission was requested to reopen Generic Issues B-19 and B-59, reopen the ATWS rulemaking proceeding, and
m,,
.s (a reconsider the use of the end-of-cycle circulation pump trip on BWRs.
Ms. Hiatt gave as grounds for the Petition that the LaSalle Event has serious safety implications for all BWRs and that the Nuclear Regulatory Cosnission (NRC) had failed to take appropriate regulatory action in response to the LaSalle Event.
On August 26, 1988, the Director, Office of Nuclear Reactor Regulation (NRR),acknowledgedreceiptofthePetition. He informed Ms. Hiatt that (1) her request for imediate relief was denied because the allegations that formed the basis for the Petition did not reveal any new operational safety issues which posed an imediate safety cancern for continued BWR operation, (2) the Petition would be treated under 10 CFR 2.206 of the Comission's regulations, and (3) appropriate action would be taken within a reasonable time.
In the August 26, 1988 letter, the Director, NRR, acknowledged Ms. Hiatt's request to reopen the ATWS rulemaking proceedings as a request which would be treateri pursuant to 10 CFR 2.206. This request, however, will not be treated pursuant to 10 CFR 2.206 but is being treated separately as a petition for rulemaking under 10 CFR 2.802 of the Comission's regulations.
The Director has now determined that all cf Ms. Histt's requests, except for her request to reopen the ATWS rulemaking, should be denied for the reasons set forth in the " Director's Decision Pursuant to 10 CFR 2.206" (DD-89-03).
The Decision is available for inspection and copying in the Cosmission's Public Document Room, 2120 L Street N.W., Washington, D.C. 20555 and at the Local Public Document Rooms near the facilities listed below. The addresses and hours of operations for the local public document rooms may be obtained by calling the following toll-free number:
1-800-638-8081.
,I
__ _ __ _ _-_ _ a
y; ', ~
3-A copy of the Decision will be filed with the Secretary of the Comission for the Connission's review in accordance with 10 CFR 2.206(c). As provided in 10CFR2.206(c),theCecisionwillbecomethefinalactionoftheCommission twerity-five (25) days after issuance unless the Coemission on its own motion institutes review of the Decision within that time.
FOR THE NUCLEAR REGULATORY COPMISSION
+
4:: m f Thomas E. Murity, Director Office of kuclear Reactor Regulation Deted at Rockville, Maryland, this ntn of April 1989.
4
___________---_--_________-___2
,s *7 CAROLINA POWER & LIGHT CO. (Brunswick Station, Units 1 and 2, Docket Nos. 50-324 and 50-325)
CLEVELAND ELECTRIC ILLUMINATING CO., ET AL. (Perry Nuclear Power Plant, Unit 1, Docket No. 50-440)
COMMONWEALTH EDISON CO. (Dresden Nuclear Power Plant, Units 2 and 3, DocketNos.50-237and50-249),(QuadCitiesNuclearPowerPlant, Units 1 and 2, Docket Nos.50-254 and 50-265), (LaSalle County Station, Units 1 and 2, Docket Nos. 50-373 and 50-374)
CONSUMERS POWER CO. (Big Rock Point, Docket No. 50-155)
DETROIT EDISON CO. (Fermi Unit 2 Docket No. 50-341)
GENERAL PUBLIC UTILITIES (Oyster Creek Station, Docket No. 50-219)
GEORGIA POWER CO (Hatch Nuclear Power Plant, Units 1 and 2, Docket Nos. 50-321 and 50-366)
GULF STATES UTILITIES CO. (River Bend Station, Docket No. 50-458)
ILLIN0ISPOWERCO.(ClintonNuclearPowerPlant,DocketNo.50-461)
IOWA ELECTRIC LIGHT & POWER CO. (Duane Arnold Nuclear Power Plant, Docket No. 50-331)
LONG ISLAND LIGHTING CO. (Shoreham Nuclear Power Plant, Docket No. 50-322)
MISSISSIPPI POWER & LIGHT CO. (Grand Gulf Nuclear Station, Docket No. 50-416)
NEBRASKA PUBLIC POWER DISTRICT (Cooper Station, Docket No. 50-298)
NIAGARA MOHAWK POWER CORP. (Nine Mile Point, Units 1 and 2, Docket Nos. 50-220 and 50-410)
NORTHEAST UTILITIES (Millstone Unit 1, Docket No. 50-245)
NORTHERN STATES POWER CO. (Monticello Nuclear Power Plant, Docket No. 50-263)
PENNSYLVANIA POWER & LIGHT CO. (Susquehanna Steam Electric Station, Units 1 and 2, Docket Nos. 50-387 and 50-388)
PHILADELPHIA ELECTRIC CO. (Peach Bottom Nuclear Station, Units 2 and 3, Docket Nos. 50-277 and 50-278), (Limerick Nuclear Power. Plant, Unit 1 Docket No. 50-352)
POWER AUTHORIT10F THE STATE OF NEW YORK (James A. Fitzpatrick Station,
- 4 Docket No. 50-333)
PUBLIC SERVICE ELECTRIC & GAS CO. (Hope Creek Generating Station, Docket No. 50-354)
TENNESSTE VALLEY AUTHORITY (Browns Ferry Nuclear Station, Units 1, 2, and 3 Docket Nos. 50-259,50-260,and50-296)
YERMONT YANKEE NUCLEAR POWER CORP. (Vermont Yankee Nuclear Power Plant, Docket No. 50-271)
WASHINGTON PUBLIC POWER SUPPLY SYSTEM (WNP Unit 2, Docket No. 50-397) 1 l
,