ML17305B619
| ML17305B619 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/25/1991 |
| From: | Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17305B620 | List: |
| References | |
| 161-04019-WFC-J, 161-4019-WFC-J, NUDOCS 9107030123 | |
| Download: ML17305B619 (21) | |
Text
ACCELERATED DISTRIBUTION DEMONSTPA.TION SYSTEM
SUBJECT:
Application for amends to Licenses NPF-41,NPF-51 6 NPF-74, deleting iodine removal sys from Tech Specs 3.6.2.2,4.6.2.2' Bases B 3/4.6.2.2.
DISTRIBUTION CODE:
AOOID COPIES RECEIVED:LTR Q ENCL g SIZE:
TITLE: OR Submittal:
General Distribution 1'<
NOTES:STANDARDIZED PLANT Standardized plant.
Standardized plant.
D 05000528.P, 05000529 05000530 D REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9107030123 DOC.DATE: 91/06/25 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station,, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Verde Nuclear Station, Unit 3, rizona ubli
'05 00530
,AUTH.NAME AUTHOR AFFILIATION
'CONWAY,W.F.
Arizona Public Service Co.
(forme y Ari o clear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
~
RECIPIENT ID CODE/NAME PD5 LA TRAMMELL,C INTERNAL: ACRS NRR/DET/ESGB NRR/DST 8E2 NRR/DST/SICB8H7 NUDOCS-ABSTRACT OGC/HDS 1 RES/DSIR/EIB EXTERNAL NRC PDR NOTES:
COPIES LTTR ENCL 1
1 2
2 6
6 1
1 1
1 1
1 1
1 1
0 1
1 RECIPIENT ID CODE/NAME PD5 PD THOMPSON,M NRR/DET/ECMB 7,D NRR/DOEA/OTS B11 NRR/DST/SELB 7E, NRR/DST/SRXB 8E O~BP REG FILE 01 NSIC COPIES LTTR ENCL 1
'1 2
2 1
1 1
1 1
1 1
.1'
~
0 1
.1 1
1 D
NOTE TO ALL"RIDS" RECIPIENTS:
D D
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P!-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 27 ENCL 25
Arizona Public Service Company P.O. BOX 53999
~
PHOENIX, ARIZONA 85072<999 WILLIAMF. CONWAY EXECUTIVEVICEPRESIDENT NUCLEAR 161-04019-NFC/JRP June 25, 1991 Docket Nos.
STN 50-528/529/530 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station Pl-37 Washington, D.
C.
20555
Dear Sirs:
Subj ect:
Palo Verde Nuclear Generating Station (PVNGS)
Units, 1, 2, and 3
Technical Specification Amendment Request Section 3/4 3.6.2.2 and Bases File: 91-056-026; 91-005-419.05 Arizona Public Service Company (APS), herewith requests an amendment to the PVNGS Units 1, 2, and 3 Technical Specifications Sections 3.6.2.2, 4.6.2.2 and Bases B 3/4.6.2.2.
The proposed change would delete the Iodine Removal (IR) system from the Units 1, 2,
and 3 Technical Specifications.
The current IR System" design uses hydrazine as an additive to the containment spray system (CSS).
The attached Technical Specification amendment request and supporting analysis demonstrates that deletion of the IR System, with the hydrazine spray additive does not impact conclusions regarding the environmental or radiological consequences of a Large Break Loss of Coolant Accident (LBLOCA) as presented in the Updated Final Safety Analysis Report (UFSAR).
Attached with this amendment request are:
Og O,'.
B.
C.
D.
E.
F.
G.
910703012 05000528 23 910625 PDR ADOC PDR P
PP Description of Amendment Request Purpose of the Technical Specification Need for the Technical Specification Amendment Bases for No Significant Hazards Consideration Safety Analysis of the Proposed Amendment Request Environmental Impact Consideration Determination Revised Technical Specification Amendment Pages graf P o~f
J 0
e' 1
kl
161-04019-<<F0/0RF June 25, 1991 U.
S. Nuclear Regulatory Commission Attn: Document Control Desk Page 2
..Pursuant to 10.CFR 50.91(b)(1),
a copy of this.request is being.forwarded to the Arizona Radiation Regulatory Agency.
If there are any questions, please contact Michael E. Powell of my staff at (602) 340-4981.
Sincerely, WFC/JRP/pmm Attachments CC:
J.
B. Martin C.
M. Trammell D. H.
Coe A. C. Gehr A. H. Gutterman C.
F. Tedford (all w/attachment)
~
~
giO+O5OJ~
161-04019-WFC/JRP June 25, 1991 STATE OF ARIZONA
)
) ss.
COUNTY OF HARICOPA
)
I, W.
F.
- Conway, represent that I am Executive Vice President Nuclear, that the foregoing document has been signed by me on behalf of Arizona Public Service Company 'with full authority to do so, that I have read such document and know its contents, and that to the best of my knowledge and belief, the statements made therein are true and correct.
W.
F.
Conway Sworn To Before Me This g5 Dey Of 1991.
Hy Commission Expires
, Not;arv Public
~ e o
F
gE
ATTACHMENT 1 TECHNICAL SPECIFICATION PROPOSED AMENDMENT A.
ESCRI T ON 0 AM NDMENT RE UEST The Technical Specification and Bases dealing with the Iodine Removal (IR) System equipment, Section 3/4.6.2.2, will be deleted and the equipment abandoned in place.
The existing Technical Specification for the Containment Spray System (CSS),
Section 3/4.6.2.1, addresses iodine removal as one of the functions of this system in the bases.
This will remain valid even though the hydrazine additive will be removed from the spray.
Recent studies have shown that adequate radioiodine control may be accomplished without employing a spray chemical additive (hydrazine at PVNGS) provided that the pH in the sump is maintained at a high enough level to prevent re-evolution of iodine during the recirculation phase after a Large Break Loss of Coolant Accident (LBLOCA).
Maintenance of long term sump pH will continue to be accomplished using trisodium phosphate (TSP) baskets on the containment floor.
The TSP system, as described in Technical Specification 3/4.5.2.,
remains valid.
B.
PURPOSE OF THE TEC NICAL SPECIFICATION The operability of the IR System ensures that sufficient hydrazine is added to the containment spray in the event of,a LBLOCA.
The limits on hydrazine, volume and concentration ensure adequate chemical availability to remove iodine from the containment atmosphere following a LBLOCA. This methodology was based on the guidance in Standard Review Plan (SRP), 6.5.2, Revision 1.
- However, SRP 6.5.2 has been revised (Rev.
2, December 1988).
Revision 2 to SRP 6.5.2 presents a revised methodology for calculation of the concentration of post'-LOCA fission products inside containment that recognizes recent studies on the behavior of radioiodine in the post-LOCA environment.
Using this revised methodology, it has been demonstrated that removal of the chemical additive from the CSS will not result in significant increase in post-LOCA doses.
ED FOR THE TECHNICAL SPECIFICATION AMENDM NT Removal of the IR System from the Technical Specifications has an overall beneficial effect on the facility.
The chemical additive hydrazine is caustic and a carcinogen and hazardous to work with.
Elimination of the IR System will,reduce equipm'ent maintenance and surveillance and also increase system reliability by removing active components that are subject to potential failure.
The IR System has proven to be very burdensome and its maintenance required considerable effort on the part of plant personnel.
D.
BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION The Commission has provided standards for determining whether a
significant hazards consideration exists as stated in 10 CFR 50.92.
A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with a proposed amendment would not:
(1) Involve a
significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
A discussion of these standards as they relate to the amendment request follows:
Standard 1 -- Involve a significant increase in the probability or consequences of an accident previously evaluated.
The probability or consequences of an accident previously evaluated will not be increased by the proposed Technical Specification amendment.
The IR System is used only to mitigate the consequences of a
Deletion of this system will not increase the probability of occurrence of an accident since the system only operates to mitigate an accident.
The doses have been recalculated and are still well below regulatory limits. Thyroid doses for the Control Room, Exclusion Area Boundary (EAB) and Low Population Zone (LPZ) have been significantly reduced.
The slight increases in the whole body and beta skin doses in the Control Room, EAB and LPZ are well below 10 CFR 50, Appendix A, (GDC 19),
and 10 CFR 100 limits.
As discussed in Attachment 2, the increases in beta skin doses and whole body doses is due primarily to a refinement in the computer program (LOCADOSE),
which now considers daughter products and refinement of the containment model to three regions (main sprayed region, auxiliary sprayed region, and unsprayed region) rather than two (sprayed region, and unsprayed region).
lf t
I
The equipment necessary for post:-LOCA operation willstill function in the environment without hydrazine.
The radiation environment in containment is affected by deletion of the IR System.
Using the guidance in Revision 2 of SRP 6.5.2, a larger fraction of the radioiodines willplate-out on containment surfaces, increasing the contribution from plate-out to equipment qualification doses.
An analysis was performed to quantify the changes to equipment doses resulting from deletion of the IR System (Attachment 2, Reference 27).
The radiological impact on equipment is within the parameters of the environmental qualification boundaries and is documented in Engineering Study 13-NS-A25, Rev.
0.
The long term pH of the sump is maintained by the trisodium phosphate (TSP) in the lower level of the containment building.
Deletion of the IR System does not affect the long term pH control provided by the
- TSP, therefore, the equipment remains qualified 'for, the resulting pH.
The hydrogen generation in containment post-LOCA is also dependent upon pH;
- however, as this factor is not affected, hydrogen generation will remain unchanged.
Therefore, the proposed amendment does not involve a significant increase in, the probability or consequences of an accident previously evaluated.
Standard 2 -- Create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed Technical Specification amendment will not introduce any new operational conditions or any new accidents not previously analyzed.
The IR System is designed to operate only to mitigate the consequences of a LBLOCA and is not an event initiator.
Deleting the system will not affect the CSS.
The CSS pumps will continue to have sufficient net positive suction head (NPSH) without the addition of hydrazine to perform their function.
The containment spray risers, headers and nozzles will fillas before and perform their intended function.
There will be no additional operational requirements for either the CSS nor the passive TSP.
The IR System equipment willbe taken out of service, and no modifications willbe required to the CSS or the TSP baskets.
These components will continue to perform their accident mitigation functions in the same manner.
The TSP baskets are a"passive system for raising the pH in the containment sump.
Neither the CSS or the TSP is used during normal plant operation.
Therefore, the deletion of the IR System will not create the possibility of a new or different kind of accident from any accident previously evaluated.
4 l
I' I
Standard 3 -- Involve a significant reduction in a margin of safety.
The proposed Technical Specification amendment will not reduce the margin of safety.
Thyroid doses for the Control Room, EAB, and LPZ have been reduced.
Post-LOCA whole body and beta skin doses increase only slightly and remain well within regulatory limits.
The major contributor to the increase in the doses is due to the fact that the computer program (LOCADOSE)
- used, now considers daughter products whereas the original analysis used an earlier version of (LOCADOSE) which did not consider daughter products.
Additionally, the containment model was changed from a two region model (sprayed and unsprayed) to a three region model (main sprayed, auxiliary sprayed and unsprayed).
There willbe no additional operational requirements for either the CSS or the passive TSP addition.
These components will continue to perform their-accident mitigation functions in the same manner.
Neither the CSS nor the TSP is used during normal plant operation.
Therefore, the deletion of the IR System will not reduce the margin of safety.
The proposed amendment is consistent with the current regulatory guidance for fission product removal from the post accident containment environment.
E.
SAFETY ANALYSIS OF THE PROPOSED AMENDMENT RE UEST
~
~
1/
The proposed Technical Specificatj.on amendment wo'uld delete the IR System from Units 1,
2, and 3 Technical Specifications, and the equipment would, be abandoned in place.
SRP 6.5.2 "Containment Spray as a Fission 'Product Cleanup System,"
establishes guidelines for taking credit for removal 'of radi'oiodine by the CSS.
The SRP is used to establish the percent of initial release from the core and to determine how much this release is reduced, by mechanisms such as containment spray (washout) and plate-out (surface deposition).
The iodine removal coefficients calculated using the SRP guidelines are then used in the calculation of post-accident releases and resulting doses.
Revision 2 to SRP 6.5.2 presents a revised methodology for calculation of the concentrations of post-LOCA fission products inside containment.
Using this revised methodology, it has been demonstrated that removal of hydrazine additive from CSS will not result in a significant increase in post-LOCA doses outside of containment.
1 I
The proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated.
The IR System is used only to mitigate the consequences of a LBLOCA.
Deletion of the IR System will not increase the probability of occurrence of a LBLOCA since it is equipment that does not normally operate.
The doses have been recalculated and have been shown to remain well below regulatory allowables (Table 1);
therefore, there is no significant increase in the consequences of an accident as a result of the IR System deletion.
The proposed amendment will not create the possibility of a new or different kind of accident from any accident previously analyzed.
No increased operating demands willbe placed on the CSS as a result of the change.
The CSS pumps have sufficient NPSH without the addition of hydrazine to perform their function.
The containment spray risers will still fillas before and perform their intended function.
The deletion of the hydrazine will not create new or different accidents.
The results of the change are within all acceptable criteria for postulated post-LOCA doses with respect to the methodology specified in the SRP, Section 6.5.2, Revision 2.
As discussed previously, the systems that remain are not being modified.
Therefore, the design basis of these systems remains the same and will not create the possibility of a new or different kind of accident from any accident previously analyzed.
The proposed amendment will not involve a significant reduction in a
margin of safety.
The analyses provided in Attachment 2
demonstrate that without the IR System, post-LOCA doses remain well below regulatory limits.
Therefore, operation of the plant without the IR System will not involve a significant reduction in a margin of safety.
I
TABLE 1 DOSE COMPARISON
SUMMARY
~
THYROID DOSE WHOLE BODY DOSE BETA SKIN DOSE UFSAR NEW ALLOWABLE UFSAR NEW ALLOWABLE UFSAR NEW ALLOWABLE EAB LPZ CONTROL ROOM 106 156 8.1 80 300 80 300 7.0 30 1.7 0.8 0.7 2.5 1.0 0.95 25 25 9.3 19.1 30 ALL VALUES IN REM o'OURCE ATTACHMENT 2, TABLE 10 EAB (0-2 hrs)
LPZ (0-30 days)
Control Room (30 days
+ Single Failure of one Essential HVAC Train)
lt li J
'F.
ENVI ONMENTAL IMPACT CONSIDERATION DETERMINATION The proposed Technical Specification amendment does not involve an unreviewed environmental safety question because operation of PVNGS Units 1,"2, and 3 in accordance with this amendment would not:
1)
Result in a significant increase in any adverse environmental impact previously evaluated in the Final Environmental Statements (FES) as modified by the staff's testimony to the Atomic Safety and Licensing board; or 2)
Result in a significant change in effluents or power levels; or 3)
Result in matters not previously reviewed in the licensing basis for PVNGS which may have a significant environmental impact.
Revision 2
to SRP 6.5.2 presents a
revised methodology for calculation of the concentration of post-LOCA fission products.
Using this revised methodology, it has been demonstrated that removal of the IR Syst: em will not result in a significant increase in doses at the Exclusion Area Boundary or the Low Population Zone.
The increases that do occur (whole body and beta-skin) are attributable to refinement of the computer
- model, LOCADOSE.
This computer model has been modified since the original analysis to include daughter products of isotopes.
Inclusion of these daughter products results in slightly higher doses.
- However, the values remain well within regulatory limits.
G.
MARKED-UP TECHNICAL SPECIFICATION AMENDMENT'PAGES VII 3/4 6-17 3/4 6-18 B3/4 6-3
P pJ
.C i
'I
~
'I g
~
V