ML17306A961
| ML17306A961 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 09/08/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17306A956 | List: |
| References | |
| NUDOCS 9209210078 | |
| Download: ML17306A961 (11) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
'M09210078 920908 PDR ADOCK 05000528-.
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 64 TO FACILITY OPERATING LICENSE NO.
NPF-41 AMENDMENT NO. 50 TO FACILITY OPERATING LICENSE NO.
NPF-51 AND AMENDMENT NO. 37 TO FACILITY OPERATING LICENSE NO. NPF-74 ARIZONA PUBLIC SERVICE COMPANY ET AL.
PALO VERDE NUCLEAR GENERATING STATION UNIT NOS.
1 2
AND 3 DOCKET NOS.
STN 50-528 STN 50-529 AND STN 50-530
- 1. 0 INTRODUCTION By letter dated June 25,
- 1991, the Arizona Public Service Company (APS or the licensee) submitted a request for changes to the Technical Specifications (TS) for the Palo Verde Nuclear Generating Station, Units 1, 2,
and 3 (Appendix A
to Facility Operating License Nos.
NPF-41, NPF-51, and NPF-74, respectively).
The Arizona Public Service Company submitted this request on behalf of itself, the Salt River Project Agricultural Improvement and Power District, Southern California Edison Company,,
El Paso Electric Company, Public Service Company of New Mexico, Los Angeles Department of Water and
- Power, and Southern California Public Power Authority.
The. proposed changes would eliminate the hydrazine additive in the containment spray system at the Palo Verde Nuclear Generating Station Units 1, 2,
and 3, by deleting Section 3/4.6.2.2
" Iodine Removal System" from the Technical Specifications (TS).
The existing TS for the Palo Verde nuclear units requires use of the containment spray system in conjunction with the iodine removal system for removal of iodine from a post-accident containment atmosphere.
The iodine removal system adds hydrazine to the containment spray solution.
The licensee has pointed out in the submittal that the revised Standard Review Plan (SRP)
Section 6.5.2, "Containment Spray as a Fission Product Cleanup System,"
issued in December
- 1988, no longer requires chemical additive injection into the containment spray solution so long as the containment sump solution pH is maintained basic.
The licensee also stated in the submittal that at Palo Verde, the containment sump solution pH will be maintained above 7.0 using trisodium phosphate which is contained in baskets located on the containment floor.
The licensee
- has, therefore, proposed elimination of the hydrazine addition to the containment spray solution and has requested deletion of TS Section 3/4.6.2.2 from the Technical Specifications for the Palo Verde nuclear units and has provided justification for its removal, In its technical justification, the licensee recalculated the offsite and control room operator
doses in accordance with the revised SRP Section 6.5.2 to show i.ts compliance with the acceptable criteria stated in the section.
The licensee stated in the submittal that the removal of the hydrazine additive will reduce equipment maintenance and surveillance efforts, and it will also reduce the potential hazards (caustic effect) to personnel and property from leaking seals,
- pumps, and valves.
- 2. 0 EVALUATION
- 2. 1 Radiolo ical Issues The as-built and operational Palo Verde containment spray system consists of two independent 100%-capacity loops each containing a containment spray
- pump, a shutdown cooling heat exchanger, a spray header, and associated
- valves, piping, and instrumentation.
Each of the two containment spray pumps is rated at 3650 gpm.
Containment spray is automatically initiated by a containment spray actuation signal (CSAS), which occurs on high-high containment pressure.
Upon receipt of a CSAS the containment spray pumps are started, the spray header isolation valves are opened and spray water from the Refueling Water Tank is delivered to the containment spray headers.
Positive displacement pumps will also automatically start and add hydrazine from the hydrazine tank to the containment spray lines.
When the water level in the RWT reaches a
specified low setpoint, a recirculation actuation signal (RAS) will automatically align the containment spray pump suctions to the, containment sumps by opening the containment sump isolation valves.
The staff evaluated iodine removal effectiveness of the containment spray system with the hydrazine addition in accordance with Revision 1 (July 1981) of the SRP Section 6.5.2 and has accepted the design in Supplement No.
5 to the Palo Verde Safety Evaluation Report (NUREG-0857) dated November 1983.
Subsequently, the staff issued a revision of the SRP Section 6.5.2 in December 1988.
The revision acknowledged that a chemical additive is not necessarily required during spray injection so long as pH control is maintained for the sump water during post-accident conditions.
The revision also provided a
revised methodology for calculation of iodine removal efficiencies for the containment spray system.
Using the revised methodology, the licensee calculated the offsite and control room operator doses following a postulated LOCA.
This calculation demonstrated that the requested removal of the chemical additive to the containment spray lines will not result in a significant increase in the offsite and control room operator doses and that these doses still meet the guidelines set forth in 10 CFR 100 and GDC-19.
The staff has verified the licensee's dose calculation by performing an independent radiological consequence analysis using the new iodine removal coefficients calculated in accordance with the methodology provided in the revised SRP Section 6.5.2 and using the same assumptions previously used for LOCA dose calculation in Supplement No.
5 (Table 15-1) of the Palo Verde SER.
The revised iodine removal coefficients and associated radiological
consequences of a LOCA are listed in Tables 1
and 2.
A's shown in the Table 2, the staff finds that the offsite and control room operator doses are.still within the dose guidelines set forth in 10 CfR 100 and GDC-19, thus verifying the licensee's calculation.
The staff concludes that, with respect to radiological
- issues, the proposed changes to the Palo Verde TS concerning elimination of the hydrazine additive to-the containment spray lines are acceptable.
This conclusion is based on (1) the staff review of the licensee's analysis and (2) the independent analysis by the staff which confirms that the distances to the exclusion area boundary and to the low population zone of the Palo Verde site are still sufficient to provide reasonable assurance that the radiological consequences of a LOCA will be within the dose guidelines set forth in 10 CFR 100 and that control room operator doses following a LOCA will be within the dose guidelines set forth in GDC-19.
Therefore, the staff finds the conclusions stated in, Supplement No.
5 of the Palo Verde SER Section 6.4, "Control Room Habitability," and Section 15.4, "Radiological Consequences of Design Basis Accidents" are not affected and still remain the same.
2.2 Materials and Chemistr Issues During the injection phase, the licensee proposes to operate the containment sprays with borated water without the hydrazine additive.
The pH of this water could be well below 7.
Using the information currently available on iodine removal and the guidance provided in Section 6.5.2 of the Standard Review Plan, the licensee has demonstrated
- that, even at a relatively low pH, elemental iodine could be efficiently removed from the post accident containment atmosphere without the presence of hydrazine, provided the spray solution was free from previously dissolved iodine.
This occurs because the rates of removal of elemental iodine are determined by the first-order, removal coefficients which are independent of pH and chemical nature of the spray solution.
The same applies to the removal coefficients for particulates iodine which is controlled only by hydrodynamical characteristics of the sprays.
The licensee calculated these coefficients using the methods given in Section 6.5.2 of the Standard Review Plan and found them to be conservative relative to the coefficients determined in the original evaluation which was approved by the staff.
Similar conservatism existed in the evaluation of decontamination factors.
During the recirculation phase, spray water will come from the sump and will contain dissolved
- iodine, removed from the containment atmosphere during the injection phase.
In radiation environment this iodine could be revolatilized and released back to the containment if pH of the solution is too low.
In order to prevent it from happening, the pH of the sump solution should be kept above 7.
Currently, the licensee has a provision for maintaining pH higher than 7 by means of trisodium phosphate kept in the basket located in the sump.
During an accident this chemical will dissolve in the sump water and will buffer its pH at the above 7 value.
Because hydrazine is a very weak base, its removal from the sprays will not change this pH control mechanism.
There is also another reason for maintaining solution in the sump alkaline.
Higher pH minimizes corrosion of metallic surfaces.
Chloride induced stress corrosion cracking of austenitic stainless steel components is considerably reduced if pH of the solution is maintained above 7.
Short exposure to low pH water during the injection phase will not cause significant stress corrosion
- cracking, but more extended exposure during the recirculation phase may result in a significant damage.
Section
- 6. 1. 1. of the Standard'eview Plan (Branch Technical Position HTEB 6-1) recommends pH in the 7 to 9.5 range.
The current plant design ensures that alkaline pH is maintained in the sump and'emoval of hydrazine additive would not significantly affect this condition.
Control of sump pH is also required to minimize hydrogen generation by corrosion of aluminum and zinc on galvanized surfaces and in organic coatings on the containment surfaces.
The licensee has shown that the proposed deletion of hydrazine from the spray solution will not affect its chemical nature sufficiently to make it more a corrosive medium for aluminum and zinc.
Previously approved analyses for hydrogen generation
- remains, therefore, applicable.
For the same reason deletion of hydrazine will not significantly change the effect spray solution has on the equipment located in the containment and the previously approved environmental qualification will remain valid.
Finally,,
the proposed elimination of hydrazine will not compromise the containment spray system's operational capability.
We have reviewed the licensee's analyses and performed our independent verifications and concur with the licensee's just.ifications for elimination of the hydrazine additive.
Based on the above evaluation, the staff concludes that, with respect to materials and chemistry issues, the proposed modification to Palo Verde Nuclear Generating Station's containment spray system is acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Arizona State official was notified of the proposed issuance of the amendment.
The State official had no comments.
- 4. 0 ENVIRONMENTAL CONSIDERATION The amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released
- offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a
proposed finding that the amendments involve no significant hazards considera-
- tion, and there has been no public comment on such finding (56 FR 43803).
Accordingly, the amendments meet the eligibility criteria for categorical
exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Commission has concluded, based on the cons.iderations discussed
- above, that (1) there is reasonable assurance that the health and safety of.the public will not be endangered by operation in the proposed
- manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
J.
Lee K, Parczewski T. Chandra Date:
September 8,
1992
TABLE 1
Containment S ra Iodine Removal Efficiencies hour -1 Current 1
New Elemental iodine Organic iodine Particulate iodine 21 0.41 20 0.34 Decontamination Factor 200
- 6. 51 (1)
Table 15-1 of Supplement No.
5 to Palo Verde SER (NUREG-0857)
TABLE 2 Radiolo ical Conse uences rem
~EAB 2
~LP2 3
Control.Room Thyroid Whole Body 2.5
<O.l Containment Leakage 94 ESF Leakage 14 Thyroid Whole Body Thyroid Whole Body 83 1.1 9.5
<1 43
<O.l
<0.5
<1 Total 108
<2.6 126
<1.2
<10.0
<1 (2)
Exclusion Area Boundary (3)
Low Population Zone Outer Boundary
r
-'ocket Nos.
50-528, 50-and 50-530 e
Mr. William F.
Conway Executive Vice President, Nuclear Arizona Public Service Company Post Office Box 53999
- Phoenix, Arizona 85072-3999
Dear Mr. Conway:
'eptember 8
92
SUBJECT:
ISSUANCE OF AMENDMENTS FOR THE PALO VERDE NUCLEAR GENERATING STATION UNIT NO.
1 (TAC NO. H80905),
UNIT NO.
2 (TAC NO. M80906),
AND UNIT NO.
3 (TAC NO. M80907) s The Commission has issued the enclosed Amendment No.
64 to Facility Operating License No. NPF-41, Amendment No.
50 to Facility Operating License No. NPF-51, and Amendment No.
37 to Facility Operating License No.
NPF-74 for the Palo Verde Nuclear Generating Station, Uni,t Nos.
1, 2, and 3, respectively.
The amendments consist of changes to the Technical Specifications in response to your application dated June 25, 1991.
These amendments delete the Iodine Removal System from Technical Specifications 3/4 3.6.2.2 for Units 1, 2, and 3.
The Iodine Removal System uses hydrazine as an additive to the containment spray system at Palo Verde.
The removal of the hydrazine additive from the contai'nment spray system will not result in a significant increase in post-Loss of Coolant Accident (LOCA) doses outside of containment.
A copy of the related Safety Evaluation is also enclosed.
A notice of issuance will be included in the Commission's next regular biweekly Federal
~Re ister notice.
Sincerely, Original signed by:
Enclosures:
l.
Amendment No. 64 to NPF-41 2.
Amendment No. 50 to NPF-51 3.
Amendment No. 37 to NPF-74 4.
Safety Evaluation Catherine M. Thompson, Project Manager Project Directorate V
Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc w/enclosures:
See next page l!LKRRB TIOII:
See next page OFC
- NAME, DATE LA:PDV DRPW DP5%IIIer
/92 PH:PDV.DRPW CT son:mc
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/ R /92 OFFICIAL RECORD COPY DOCUMENT NAME:
PV80905.AMD
DoCL'.et Nos.
50-528, 50-52 and 50-530 Hr. William F.
Conway Executive Vice President, Nuclear Arizona Public Service Company Post Office Box '53999
- Phoenix, Arizona 85072-3999 September 8,
1992
Dear Hr. Conway:
SUBJECT:
ISSUANCE OF AMENDMENTS FOR THE PALO VERDE NUCLEAR GENERATING STATION UNIT NO.
1 (TAC NO. H80905),
UNIT NO.
2 (TAC NO.- H80906),
AND UNI'T NO.
3 (TAC NO. H80907)
The Commission has issued the enclosed Amendment No.
64 to Facility Operating License No. NPF-41, Amendment No.
50 to Facility Operating License No.
NPF-51, and 'Amendment No.
37 to Facility Operating License No, NPF-74 for the Palo Verde Nuclear Generating Station, Unit Nos.
1, 2,
and 3, respectively.
The amendments consist of changes to the Technical, Specifications in response to your application dated June 25, 1991.
These amendments delete the Iodine Removal System from Technical Specifications 3/4 3.6.2,2 for Units 1, 2, and 3.
The Iodine Removal System uses hydrazine as an additive to the containment spray system at Palo Verde.
The removal of the hydrazine additive from the containment spray system will not result in a significant increase in post-Loss of Coolant Accident (LOCA) doses outside of containment.
A copy of the related Safety Evaluation is also enclosed.
A notice of issuance will be included in the Commission's next regular biweekly Federal
~Re ister notice.
Sincerely, I
Original signed by:
Catherine M. Thompson, Project Manager Project Directorate V
Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc w/enclosures:
See next page DISTRIBUTION:
See next page
Enclosures:
1.
Amendment No. 64 to NPF-41 2.
Amendment No. 50 to NPF-51 3.
Amendment No. 37 to NPF-74 4.
Safety Evaluation
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/92 Tguay OFFICIAL RECORD COPY 1
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PV80905.AMD 1500)9 VM>f7~>&
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 September 8,
1992 Docket Nos.
50-528, 50-529 and 50-530 Mr. William F.
Conway Executive Vice President, Nuclear Arizona Public Service Company Post Office Box 53999
- Phoenix, Arizona 85072-3999
Dear Hr. Conway:
SUBJECT:
ISSUANCE OF AMENDMENTS FOR THE PALO VERDE NUCLEAR,GENERATING STATION UNIT NO.
1 (TAC NO. M80905),
UNIT NO.
2 (TAC 'NO. H80906),
AND UNIT NO.
3 (TAC NO. H80907)
The Commission has issued the enclosed Amendment No.
64 to Facility Operating License No. NPF-41, Amendment No.
50 to Facility Operating License No. NPF-51, and Amendment No.
37 to Facility Operating License No.
NPF-74 for the Palo Verde Nuclear Generating Station, Unit Nos.
1, 2,
and 3, respectively.
The amendments consist of changes to the Technical Specifications in response to your application dated June 25, 1991.
These amendments delete the Iodine Removal System from Technical Specifications 3/4 3.6.2.2 for Units 1, 2, and 3.
The Iodine Removal System uses hydrazine as an additive to the containment spray system at Palo Verde'he removal of the hydrazine additive from the containment spray system will not result in a significant increase in post-Loss of Coolant Accident (LOCA) doses outside of containments A copy of the related Safety Evaluation is also enclosed, A notice of issuance will be included in the Commission's next regular biweekly Federal
~Re ister notice.
Sincerely,
Enclosures:
1.
Amendment No. 64 to NPF-41 2.
Amendment No. 50 to NPF-51 3.
Amendment No. 37 to NPF-74 4.
Safety Evaluation cc w/enclosures:
See next page Catherine H. Thompson, Project,Manager Project Directorate V
Division of Reactor Projects III/IV'/V Office of Nuclear Reactor Regulation
Hr. William F.
Conway Arizona Public Service Company Palo Verde CC:
Nancy C. Loftin, Esq.
Corporate Secretary
& Counsel Arizona Public Service Company P. 0.
Box 53999, Hail Station 9068
- Phoenix, Arizona 85072-3999 James A. Beoletto, Esq.
Southern California Edison Company P. 0.
Box 800
- Rosemead, California 91770 Senior Resident Inspector U.S, Nuclear Regulatory Commission HC-03 Box 293-NR
- Buckeye, Arizona,
.85326 Regional Administrator, Region V
U.
S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Hr. Charles B. Brinkman, Manager Washington Nuclear Operations ABB Combustion Engineering Nuclear Power 12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 Hr. William A. Wright, Acting Director Arizona Radiation Regulatory Agency 4814 South 40 Street
- Phoenix, Arizona 85040 Chairman Haricopa County Board of Supervisors 111 South Third Avenue
- Phoenix, Arizona 85003 Jack R.
- Newman, Esq.
Newman
& Holtzinger, P.C.
1615 L Street, N.W., Suite 1000 Washington, D.C.
20036 Curtis Hoskins Executive Vice President and Chief Operating Officer Palo Verde Services 2025 N. 3rd Street, Suite 220
- Phoenix, Arizona 85004 Roy P.
Lessey, Jr.,
Esq.
Bradley W. Jones, Esq.
Arkin, Gump, Strauss, Hauer and Feld El Paso Electric Company 1333 New Hampshire Ave., Suite 400 Washington, D.C.
20036
September 8,
1992 Docket Nos.
50-528, 50-529 and 50-530
SUBJECT:
ISSUANCE OF AMENDMENTS FOR THE PALO VERDE NUCLEAR GENERATING STATION UNIT NO.
1 (TAC NO. M80905),
UNIT NO.
2 (TAC NO. H80906),
AND UNIT NO.
3 (TAC NO. H80907)
DISTRIBUTION:
+Docket Files )
NRC 5 Local PDRs PDV r/f PDV p/f BBoger HVirgilio DFoster CThompson CTrammell TQuay
- OGC, 15B18
- DHagan,
'HNBB3206 GHi 1 1 (12),, Pl-37
'WJones, P-370 CGrimes,,
1'IE22 ACRS (10),
P-315
- OPA, 2G5 OC/L'FHB, MNBB4503
- KPerkins, RV Region V (12)