ML041210232

Response to Request for Additional Information for Relaxation of the Reactor Vessel Head Vent Nozzle Examination, NRC Order EA-03-009

ML041210232
Person / Time
Site:	Palo Verde
Issue date:	04/23/2004
From:	Mauldin D Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-05095-CDM/SAB/RJR, EA-03-009
Download: ML041210232 (2)

Text

LAMS David Mauldin EA-03-009 Vice President Mail Station 7605 Palo Verde Nuclear Nuclear Engineering TEL (623) 393-5553 P.O. Box 52034 Generating Station and Support FAX (623) 393-6077 Phoenix, AZ 85072-2034 102-05095-CDM/SAB/RJR April 23, 2004 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

References:

1. Letter 102-05031-GRO/SAB/RJR, "Relief Request No. 24 - Request for Relaxation of NRC Order EA-03-009,Section IV.C.(1)(b)

Requirements for the Reactor Head Vent Nozzle," dated January 14, 2004.

2. Letter 102-05070-CDM/SAB/RJR, "Relief Request No. 24-Request for Addition Information,' dated March 11, 2004.

3. Letter 102-05084-GRO/SAB/RJR, "Relief Request No. 24-Response to Second Request for Additional Information," April 9, 2004.

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528 Additional Information for the Request for the Relaxation of the Reactor Vessel Head Vent Examination In Reference 1, Arizona Public Service Company (APS) requested relaxation from NRC Order EA-03-009 for the reactor head vent nozzle. In References 2 and 3, APS provided responses to NRC questions regarding the relaxation. In a telephone conversation on April 22 the NRC requested additional information regarding the estimated radiological dose that would be incurred if the examination was performed during the current refueling outage (Unit 1 eleventh refueling outage--U1 R11).

APS has performed a review of the steps required to perform an examination of the reactor head vent nozzle using the current radiological condition in Unit 1. This inspection would be performed without reliance on the previously submitted relaxation to the NRC Order EA-03-009. The results of the review determined that the radiological dose that would be incurred for this inspection during Ul R1 1, including the manual actions necessary to obtain an acceptable examination, would be approximately 80 to 100 man rem.

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US NRC Document Control Desk Response to Request for Additional Information for Relaxation of the Reactor Vessel Head Vent Nozzle Examination, NRC Order EA-03-009 Page 2 If the relaxation is granted for Ul R11, APS would pursue the development of engineered tooling and implementation techniques and plan the necessary activities to save a significant amount of radiation exposure during future examinations. It is anticipated that special tooling and mockups could be developed along with the necessary changes to complete the examination in the fall outage (Unit 3, eleventh refueling outage--U3R 1I) and potentially incur a radiological dose of less than an estimated 25 man rem. The savings in dose is estimated to be substantial due to this development of engineered tooling and implementation techniques that would enable some of the tasks to be performed remotely instead of manually in close proximity to the high radiation fields of the reactor vessel head. This would also enable APS to make the necessary changes to ensure an examination of the reactor vessel head vent nozzle can be performed in accordance with the NRC Order without reliance on a relaxation similar to that submitted in Reference 1. This also allows APS to thoroughly examine the modification alternatives to minimize stresses at the head vent nozzle.

This request is for U 1 R11 only. APS requests review and approval of this request for Unit 1 prior to Mode 2 entry from the Unit 1 refueling outage. Mode 2 entry is currently scheduled for May 1, 2004.

This letter contains one new commitment to develop the special tooling and techniques and make the necessary changes to ensure an examination of the reactor vessel head vent nozzle can be performed in accordance with the NRC Order without reliance on a relaxation similar to that submitted in Reference 1. Should you have any questions, please contact Thomas N. Weber at (623) 393-5764.

Sincerely, CDM/SAB/RJR/

cc:

J. E. Dyer (w/Enclosure)

B. S. Mallett (w/Enclosure)

M. B. Fields (w/Enclosure)

N. L. Salgado (w/Enclosure)