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~>>*w" UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 October 18, 1983 MEMORANDUM FOR:
Darrell G. Eisenhut, Director Division of Licensing FROM:
SUBJECT:
Refer ence:
Hugh L. Thompson, Jr., Director Division of Human Factors Safety SAFETY EVALUATION SUPPLEMENT FOR BWR EMERGENCY PROCEDURE GUIDELINES Letter from D.
G. Eisenhut (NRC) to T. Dente (BWROG) dated February 4, 1983, with SER enclosed Plant Names:
See enclosed list (Enclosure 1)
Multiplant Item No.:
F-05 Responsible Branch:
ORB 4'5 Project Manager:
J.
Lyons DHFS Branch Involved:
PSRB TAC No.:
43505 Our evaluation of Revision 3 to the BWR Emergency Procedure Guidelines is enclosed (Enclosure 2).
This evaluation is applicable to all General Electric BWR/1 through BWR/6 plants.
The evaluation was performed for a prepublication draft attached to.Owners Group letter BWROG-8262, dated December 22, 1982, and addresses the updates from Revision 2 which incorporate a Secondary Containment Guideline, a Radioactivity Release Control Guideline and modifications to Contingency 86.
The guidelines are still not complete in that a combustible gas control guideline has not been included.
In addition, as identified in the SER for Revision 2, we are awaiting future submittals for the following:
1.
Criteria for defining containment venting pressure, and 2.
Further justification of the conservatisms in the determination of the drywell spray flow rate.
During the review of Revision 3, we obtained the comments of Branches other than PSRB.
Although the other Branches were not asked to contribute to the SER, their comments were considered in its preparation.
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CP Darrell G. Eisenhut October lS, 1983 We conclude that the Radioactive Release Guideline is acceptable, but we require additional information on the Secondary Containment Control
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Guideline before Revision 3 can be found acceptable.
This information is identified in the enclosed Request for Additional Information (Enclosure 3}.
Included with the enclosed SER is a letter (Enclosure 4) to be sent to the BWR Owners Group.
This review was performed by N. HcCoy, Nuclear Engineer and T. Greene, Nuclear Engineer of the Procedures and Systems Review Branch.
They know of no "Differing Professional Opinions" related to this review.
ug L. Thompso
, Jr.
D'rector Di 'on of Hu n Factors Safety
Enclosures:
As stated cc w/enclosures:
R. Hattson R. Purple W. Butler B. Sheron W.
Hodges D. Crutchfield J.
Lyons F.
Pagano Van Niel
ENCLOSURE 1
This report applies to the following plants:
Boston Edison Carolina Power
& Light Cincinnati Gas 5 Electric Commonwealth Edison Consumers Power Georgia Power Iowa Electric Light 8 Power Jersey Central Power 8 Light Niagara Mohawk Power Nebraska Public Power District Northeast Utilities Pacific Gas 8 Electric Philadelphia Electric Power Authority of the State of New York Tennessee Valley Authority Vermont Yankee Nuclear Power Detroit Edison Mississippi Power 5 Light Pennsylvania Power 8 Light Washington Public Power Supply System Cleveland Electric Illuminating Houston Lighting 8 Power Illinois Power Public Service of Oklahoma Long Island Lighting Northern States Power Pil grim 1
Brunswick 1
8 2
Zimmer LaSalle 1
8 2, Dresden 1 - 3, squad Cities 1
5 2 Big Rock Point Hatch 1
8 2
Duane Arnold Oyster Creek 1
Nine Mile Point 1
5 2 Cooper Millstone 1
Humboldt Bay Peach Bottom 2 8 3; Limerick 1
5 2 Fitzpatrick Browns Ferry 1 - 3; Hartsville 1 - 4; Phipps Bend 1
8 2
Vermont Yankee Enrico Fermi 2
Grand Gulf 1
8 2
Susquehanna 1
8 2
Hanford 2
Perry 1
8 2
Aliens Creek Clinton Station 1
8 2
Black Fox 1
8 2
Shoreham Monticello
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ENCLOSURE 2
EVALUATION OF EMERGENCY PROCEDURE GUIDELINES REVISION 3 BWR 1
THROUGH 6
INTRODUCTION A staff Safety Evaluation of the BMR Emergency Procedure Guidelinesr Revision 2i was issued to the BWR Owners'roup by Letter dated November, 10'982.
That Safety Evaluation concluded that the guideLines were acceptable'nder the condition that further revisions address secondary containment controL and combustible gas control.
Revision 3 addresses secondary containment controL and radioactive release controls and proposes modifications to make the depressurization step in the RPV FLooding Contingency more explicit.
The specific guidelines are discussed in detail in the foLLowing sections.
ondar Containment Control Guideline The purpose of the Secondary Containment Control guideline is to preserve the integrity of the secondary containmenti Limit radioactivity release to and from the secondary containmentr and protect the equipment in the secondary containment from an adverse environment.
Entry conditions into these guidelines are any of the following.
Differentia l pressure at or above 0 in. of water 2.
An area temperature above the maximum normal operating temperature 3.
A HVAC cooler differentiaL temperature above the maximum normal operating differential temperature
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4.
A HVAC exhaust radiation Level above the maximum normal operat ing radiat ion Level 5.
An area radiation Level above the maximum normal operating radiation Level 6.
A f Loor drain sump water Level above the maximum normal operating water Level 7.
An area water Level above the maximum normal operating water Level The staff finds that the entry conditions as specified jn the guideline are appropriate except for Items 1
and 3.
In Item 3i the guideline should be more specific in identifying the Locations that are used to determine the differentiaL temperature.
With regard to Item 1i the technical specification pressure in the secondary containment can vary in power plants from a
minus 0.25 inch of water to as Low as a minus 5.0 inches of water.
Hencer the 0 inch of water pressure may be adequate for an entry condition to the guideline for plants that have a
minus 0.25 inch of water as.their technica l specification Limitr b ut for those plants that have a
much libel the 0 inch of water pressure wi l of safety.
An acceptable entry condit Lower technicaL specification L not give the same margin ion for the di fferent ia l pressure could be based on the percent change of the differentiaL pressur e relative to a technical speci fication value and identified as being a plant unique parameter to be specified
by an absolute value by the Licensee.
We request that the BWR owners further address this item.
The secondary containment control guideline has three sections which are executed concurrently; these are:
SC/T secondary containment temperature SC/R " secondary containment radiation Level SC/L secondary containment water 'Level fP ALL three sections of the secondary containment guideline are straight-forward and contain the foLLowing three steps:
1.
If any area parameter attemper aturer radiation or water Level) exceeds or cannot be restored to its maximum normaL operating Limits isolate alL systems that 'are discharging into the area except systems required to shut down the reactors assure adequate core coolingi or suppress a working fire.
2.
If a primary system is discharging into an arear'hen before any area parameter reaches its maximum safe operating Limitr enter
(.procedure developed from the RPV Control Guideline) at (Step RC-1) and execute it concurrentLy with this procedure.'.
If a primary system is discharging into an area and an area parameter exceeds its maximum safe operating Limit in mot e than one arear ENERGENCY RPV DEPRESSURIZATION IS REQUIRED.
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In addition to the three steps mentioned above'he section for SC/T containsinstructions to operate the area coolers and HVAC if the radiation Level is below a certain value.
The typical value given is 20 mr/hr; howevers this value is a plant-specific Limit and is not included in the generic guideline review.
The guideline also contains a table entitled "Operating Values of Secondary Containment Parameters."
The use of this table should be clarified in the guideline.
Radioactivity Release Control Guideline Radioactivity release control is needed to Limit offsite radiological releases into areas outside the primary and secondary containments.
The guideline is executed concurrently with the RPV controL guideline.
The entry condition is an offsite radioactivity release rate above the plant-specific value which requires an ALert per a site emergency plan.
The operator is instructed to "Isolate all primary systems that are discharging into areas outside the primary and secondary containments except systems required to assure adequate core cooling or shut down the reactor."
This is a Logical extension of the secondary containment guidelinesr which contain a similar action statement.
If the offsite radioactivity release rate approaches or exceeds a
Level which indicates a General Emergencyi then emergency RPV depressurization
(.Contingency No.
- 2) is required.
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The steps for depressurization begin with initiation of the isolation condenseri if available.
If suppression pool water Level is above the top of the Safety Relief Valve (SRV) discharge devices the operator opens aLL Automatic Depressurization System (ADS) valves and additional SRVs untiL the number of SRVs dedicated to ADS are open.
This step should depressurize the pressure vesseL to pressures within the range of Low head pumps within three to five minutes.
If the SRV discharge points are not submergedi no SRVs should be openedi since overpressurjzation of the suppression chamber would result.
In following the guidelinesr the operator would proceed to the next step which consider s other means of depressur ization.
g If Less than the minimum number of SRVs required for emergency depressurization are open and RPV pressure is above the minimum SRV re'opening pressurei then alternate systems are used to depressurize the vessel.
The List of alternate systems includes the main condenserr which is the preferred method; the other systems Listed are of Low capacity but may be helpful.
Contingency No.
2 (Emergency Depressurization) guidelines were previously approved as part of the staf f review of Revi sio'n 2 of the BWR Guidelines theref orei we find these same actions are acceptable for the Radioactivity Release
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Control Guidelines.
These actions are an integraL part of the overaLL guideline and do not represent an undue extension of the complexity of the operator response.
$ The numerical values of the cited release rate levels are the release rates observed by the operator in the controL room andi as suchr are related to the emergency response procedures of the plant.
The acceptability of the emergency response procedures are site-specific and not part of the generic guideline reviews.
Contingency 06i RPV FLooding The previous Safety Evaluationi for Revision 2i identified a deficiency in the RPV Flooding Contingency in which RPV depressurization is an implied step rather than an explicit step.
Revision 3 corrects this deficiency by preventing aLL injection into the RPV (except boron injection) until the
'PV pressure is beLow the minimum RPV 'flooding pressure.
In particulari the number of SRVs equaL to or greater than the 5inimum Number Required for Emergency Depressurization is ident ified in Guideline Step C6-2. I.
The operator then has assurance that the RPV wiLL be depressurized and that fLooding can be accomplished with Low pressure systems.
This change addresses the staff concern and is acceptable.
CONCLUSIONS We have reviewed Revision 3 of the BWR Emer gency Procedure GuideLines and conclude that the guideline modifications covering (1) secondary containment controlr (2) radioactive release controL and (3) Contingency P6 are acceptable subject to resolution of the staff concerns identified in the Secondary Containment Control Guideline eva luat ion.
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ENCLOSURE 3
ADDITIONAL INFORMATION RE(UIRED REVISION 3 BWR EMERGENCY PROCEDURE GUIDELINES 1.
With regard to the entry conditions for the Secondary Containment Control Guideline (Guideline Page SC-l), the locations that are used to determine the differential temperature should be specifically identified.
2.
The entry condition dealing with differential pressure should be modified to allow a plant-specific value rather than the 0 (zero) inches of water presently given in the guideline.
An acceptable entry condition could be based on a percent change of the differential pressure relative to a Technical Specification value for an individual plant.
This would provide a more uniform margin of safety for all plants.
3.
The Secondary Containment Control Guideline contains a Table entitled "Operating Values of Secondary Containment Parameters."
Clarify the purpose of this Table and discuss its use in the guideline.
ENCLOSURE 4 Mr. Tom Dente, Chairman BWR Owners Group c/o Northeast Utilities Service Company Post Office Box 270 Hartford, Connecticut 06101
Dear Mr. Dente:
SUBJECT:
SAFETY EVALUATION OF "EMERGENCY PROCEDURE GUIDELINES, REVISION 3" The NRC staff has reviewed the prepublication draft of Revision 3 of the BWR Emergency Procedure Guidelines enclosed in your letter dated December 22, 1982 (BWROG-8262).
The Revision adds two new guidelines:
Secondary Con-tainment Control and Radioactivity Release Control.
In addition, a
deficiency in Contingency 86 (RPV Flooding) was corrected.
The results of our detailed review are discussed in the enclosed Safety Evaluation Supplement.
As noted in the Supplement, we find that additional information is required on the Secondary Containment Control Guideline.
This information is identified in the enclosed request for additional information.
The guidelines are still not complete in that combustible gas control guidelines have not been included.
In addition, as identified in the Safety Evaluation Report for Revision 2, we are awaiting future submittals for the following:
l.
Criteria for defining containment venting pressure, and 2.
Further justification of the conseryatisms in the determination of drywe11 spray flow rate.
The above items were discussed at a meeting on August 8, 1983, with the BWR Owners Group Emergency Procedures Committee (EPC) and we anticipate an additional submittal by the Owners Group near the end of this calendar year.
This was identified to be Revision 4 of the EPGs.
Recent correspondence from the Owners Group (BWROG-83-27, dated August 19, 1983) stated that your present plans are to deactivate the EPC and identified the Chairman of the BWROG as the primary contact for generic maintenance work.
Based upon a possible need for followup interface with the
- EPC, we request that the EPC remain active until the NRC review of Revision 4 is completed.
We also request that you consider the merits of further technical guideline improvements with regard to operational strategies for a degraded core condition.
Longer term analyses may support supplemental severe accident management guidelines.
This latter item may also influence the deactivation date for the EPC.
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t1r.
Tom Dente 2
The principal contact for supplemental guideline activity is G. t1azetis at 301-492-7254.
Sincerely, Darrell G. Eisenhut, Director Division of Licensing
Enclosures:
1.
Safety Evaluation Supplement 2.
Request for Additional Information cc w/enclosures:
General Electric Company
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