ML17306A934

Forwards Rev 1 to JCO-91-02-01, Justification for Continued Operation Steam Generator Tube Rupture Analysis Concerns.

ML17306A934
Person / Time
Site:	Palo Verde
Issue date:	08/20/1992
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML17306A935	List: ML17306A934 ML17306A936
References
102-02251-JML-T, 102-2251-JML-T, NUDOCS 9209020197
Download: ML17306A934 (6)

Text

"0 Ik RECEIVED RECEIVED HRC NRC Arizona Public Service Company 'EGION REGION '/ Y

"""' '"""'"""'"'"'""WP"" ~<<"'92-II PALO VERDE NUCLEAR GENERATING STATION 27 IO >Z 102-02251-JML/TR8/NLT JAMES M. LEVINE August'20, 1992 VICE PRESIDENT NUCLEAA PRODUCTION Mr. John B. Martin Regional Administrator, Region V U. S. Nuclear Regulatory Commission t 1450 Maria Lane, Suite 210 ~ g~ ~a >< ~ ~

Walnut Creek, CA 94596-5368

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Revision 1 to the Justification for Continued Operation-Steam Generator Tube Rupture Analysis Concerns (JCO-91-02-01)

File: 92-056-026 Please find enclosed for your information a copy of Revision 1 to the Justification for Continued Operation (JCO) for Steam Generator Tube Rupture Analysis Concerns.

Revision 1 to the subject JCO was issued for Palo Verde Units 1, 2, and 3 to administratively limit the Reactor Coolant System dose equivalent Iodine-131 to 0.6 pCi/gm. The need for this JCO, as detailed in the body of the JCO, was originally discussed with NRR PVNGS Senior Project Manager Charlie Trammell and Resident Inspector James Sloan in January 1992. A telecon was held with the NRC to discuss the issuance of Revision 1 in July 1992.

If you have any questions, please contact Thomas R. Bradish at (602) 393-5421.

Sincerely, JML/TRB/NLT/pmm Enclosure cc: C. M. Trammell J. A. Sloan A. H, Gutterman A. C. Gehr Document Control Desk 040016

<<1 ENCLOSURE REVISION 1 TO THE JUSTIFICATION FOR CONTINUED OPERATION STEAM GENERATOR TUBE RUPTURE ANALYSIS CONCERNS (JCO-91-02-01)

21240CARev 2.99 Xl90.900r2l Iaxrggr COMPANY CORRESPONDENCE IO iran 102-02218-TRB/NLT OATE: July 29r 1992

(

TO:

Sia. a: File Ext.:

FROM Sia. <<

Ext.

T. R. Bradish 82-5421 y ~~+'636 FILE:

SUBJECT.'2-177-419 Revision 1 to the Steam Generator Tube Rupture Analysis Concerns JustiTication for Continued Operation (JCO), JCO-91-02-01 (Units 1, 2 and 3)

Revision 1 to the Steam Generator Tube Rupture Analysis Concerns Justification for Continued Operation increases the administrative control on dose-equivalent Iodine-131 from 0.4 pCi/gm to 0.6 pCi/gm. An evaluation performed subsequent to the initial issue of JCO (91-02-00) determined that an administrative limit of 0.6 pCi/gm will provide the compensatory measure to ensure dose consequences will remain under the 10 'ecessary CFR Part 100 dose limits of less than 30 Rem (GIS) during a postulated SGTR + LOP.

The original limit of 0.4 pCi/gm required by Revision 0 of this JCO was chosen as the limit in January, 1992, because the limit was imposed on Unit 1 as a compensatory measure in support of the Interfacing System Loss of Coolant Accident (ISLOCA) JCO.

On October 24, 1991, Arizona Public Service Company (APS) internal validation efforts for the upgraded Emergency Operating Procedures (EOPs) identified a concern that early (relative to no operator action for 30 minutes currently assumed) operator actions could result in more steaming during the first 30 minutes of a Steam Generator Tube Rupture (SGTR) than is currently reQected in UFSAR Section 15.6.3.1, and which could result in correspondingly higher offsite doses. This concern was documented in Condition Report/Disposition Request (CRDR) 9-1-0236. Subsequent investigation determined that a Steam Generator Tube Rupture with Loss of Offsite Power (SGTR+LOP), without a single failure, could result in doses higher than those reported for a SGTR+LOP. in CESSAR Section 15.6.3.2. UFSAR Section 15.6.3 reports dose consequences resulting from a SGTR with offsite power available, and for a SGTR+LOP with a single failure (SF), but not for a SGTR+LOP.

A review of the licensing submittals and corresponding safety evaluation reports (SERs) for SGTR events determined that, following NRC review of the CESSAR SGTR and SGTR+LOP analy'ses, Palo Verde Nuclear Generating Station (PVNGS) was required to reanalyze the SGTR+LOP event with a limiting single failure, as documented in UFSAR Section 15.6.3.2. The PVNGS FSAR originally referenced CESSAR for the

Memo to File Page 2 SGTR and SGTR+LOP events. In 1988, UFSAR Section 15.6.3 was amended to replace the reference to CESSAR SGTR+LOP with the SGTR+LOP with single failure analysis from UFSAR Appendix 15A, although it is not clear why the SGTR+LOP case was removed. Hence, there exists some confusion as to the PVNGS licensing basis for a SGTR+LOP (without a single failure). In the absence of a clearly defmed PVNGS licensing basis for a SGTR+LOP, the Standard Review Plan 15.6.3 (SRP) acceptance criteria is deemed to apply.

An engineering evaluation of the radiological consequences of the postulated SGTR+LOP, incorporating operator actions consistent with both current and upgraded EOPs, was performed. Using the CESSAR assumptions for steam generator flashing and partitioning, and dispersion factors consistent with the UFSAR Section 15.6.3.2 (SGTR+LOP+SF) analysis, the evaluation results are well within the SRP 15.6.3 criteria and 10 CFR Part 100'limits (refer to Table 2, Case 4 on page 16 of the attached JCO),

though they exceed the corresponding values documented in CESSAR Section 15.6.3.

The evaluation was also performed using the more conservative UFSAR assumptions for steam generator Gashing and partitioning, By applying the compensatory action of limiting Reactor Coolant System (RCS) dose equivalent Iodine-131 to 0.6 pCi/gm, the offsite doses were verified to be in compliance with the 10 CFR Part 100 dose limits and within the acceptance criteria of SRP 15.6.3 (refer to Table 2, Case 1 on page 16 of the attached JCO). Hence, continued operation of PVNGS Units 1, 2, and 3 under the current Emergency Operating Procedures is justified.

The 0.4 pCi/gm administrative limit is, therefore, increased to 0.6 p,Ci/gm for Units 1, 2, and 3, as set forth in Revision 1 to the SGTR JCO. The above limit does not supercede the more restrictive limit of 0.2 pCi/gm currently imposed on PVNGS Units 2 and 3 for the ISLOCA JCO.

Attached is the Justification for Continued Operation; Steam Generator Tube Rupture Analysis Concerns, JCO-91-02-01, which documents the detailed safety evaluation and demonstrates that continued operation will not adversely affect the health and safety of the public. The compensatory action will remain in effect until it is demonstrated that the FSAR analyses envelope those actions that the operators may take in accordance with the EOPs. This may require changes to the EOPs, possible reanalysis and UFSAR changes.

TRB/NLT/rit Attachment