ML19270H721
| ML19270H721 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/11/1979 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8001020689 | |
| Download: ML19270H721 (4) | |
Text
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Docket Nos.: S0-327/328 Mr. H. G. Parris Manager of Power Tennessee Valley Authority 500A Chestnut Street Tower II Chattanooga, Tennessee 37401
Dear Mr. Parris:
SUBJECT:
Inservice Inspection Program at Sequoyah Enclosed are our responses to two issues on the Sequoyah inservice inspection program.
One issue is the plastic deformation of the pressurizer relief piping, and the other is on the independent review of Section XI inspection program.
Please call if there are questions.
Sincerely, j
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L. S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Project Management
Enclosure:
As stated cc: See next page.
1674 086 goos 20 o
Tenness'ee Valley Authority ccs:
Herbert S. Sanger, b. Esq'.
General Counsel Tennessee Valley Authority 400 Conr.erce Avenue E 118 33 Knoxville, Tennessee 37902 Mr. E. G. Beasley Tennessee Valley Authority W10Cl31 C 400 Connerce Avenue Knoxville, Tennessee 37902 Mr. Michael fiarding Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. David Lambert Tennessee Valley Authority 400 Chestnut Street Tower ![
Chattanooga, Tennessee 37401 1674 087
u Pressurizer Relief Pipina During hot functional testing at Sequoy:th fluclear Plant, Unit flo.1, a pipe hanger failed to slide and caused the six-inch pressurizer relief piping to undergo plastic defor ation. This occurrence was reported to the Office of Inspection and Enforcement in flonconformance Report SWP-79-5-8.
The deformed pipe was subsequently returned to its required shape by a draw bead welding technique (weld shrinkage stresses were used to realign the piping) which was qualified by the applicant. Af ter welding, the weld area was examined by radiographic and liquid penetrant inspections in accordance with the require-ments of the ASME Code,Section III and by an ultrasonic inspection in accorcance with the requirements of the ASME Code,Section XI.
The planning and performing of the nondestructive examinaticn of the Sequoyah fluclear Plant is being based upon the edition and addenda of Section XI of the ASME Code through the Summer 1975 Addenda. This addenda requires that af ter repairs by welding on the reactor coolant pressure boundary have been completed:
a pressure test shall be performed in accordance with the provisions of IWA-5000.
TVA has requested permission to use the exemption feca pressure testing that is detailed in IWA-4400 of Section XI. This e>.emption first appears in the Summer 1978 Addenda of the ASME Code.
The October 9,1979 editRn of the FEDERAL REGISTER presents an amendment to 10 CFR Part 50, 50.55a, " Codes and Standards," wnicn allows the use of portions of later editions and addenda of the ASME Code Sectiori XI, subject to approval of the Comnission.
TVA believes that the exemotion from pressure testing is justified and will not compromise the safety of the plant for the following reasons:
1.
The process of welding to realign the pipe did nst penetrate the reactor coolant pressure boundary; and 2.
The weld area was subject to all of the examination requirements of Sections III and XI of the ASME Code.
It is our position that the use of the exemption provision in the later addenda of Section XI at Sequoyah Unit flo.1 is acceptable and is justified by the reasons stated above and by the regulation as stated in 10 CFR Part 50, 30.55a.
However, in addition, we will require that this new weld on the pressuri:er relief piping be included in the inservice inspection program for Secuoyan Unit flo. I and be subject to all the inspection requirements of Section XI of tne ASME Code throughout the service life of the plant.
1674 088
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Section XI Inscection procram Section XI of the ASME Code requires that the performance of an examination by nondestructive testing be verified by an authorized nuclear inspector (AllI).
It is further required that this At1I be employed by a state or municipality of the United States or by an insurance company authorized to write boiler and pressure vessel insurance in the United States.
It was the Tennessee Valley Authority's (TVA) position that TVA would provide its own independent review of the Section XI inspection program.
TVA.was informed by the TIRC on September 21,1979 (letter L. S. Rubenstein, DPM, to H. G. Parris, TVA) that their review procedure was not acceptable.
On October 12, 1979, TVA responded (letter L. M. Mills, TVA, to L. S. Rubenstein, CFM) to our evaluation by noting that the preservice inspection for Unit fio. I was essentially complete and that it would be impractical to bring in the independent inspector at this time. TVA also stated that the independent inspector would be used for future preservice inspection work for Unit ilo. 2 and for the inservice inspection and testing of Unit ilos.1 and 2.
The inspection program developed for this plant utilizesSection XI of the ASME Code through the Summer 1975 Addenda. However, the regulation stated in 10 CFR Part 50, 50.55a(g)(1) does not require a preservice inspection to be performed on a facility wnose construction permit was ' issued prior to January 1,1971.
(The construction permits for Sequoyah Unit tios.1 and 2 were issued en May 27, 1970.)
It is our position that the preservice inspection performed en the Sequoyah plant is acceptable even if the work was not verified by an Atil since tnis inscection was not required by regulation. However, the conduct of the preservice inspection will (1) enable the applicant to determine any limitations in component access or inspectability due to design, (2) provide an opportunity to use the testing equipment before the plant components have been irradiated, and (3) provide baseline inspection data to which the inservice inspection results may be compared.
Therefore, it is our position that an exemption to the recuirement for an A?ll to verify the Sequoyah preservice inspection is not necessary, since tnis insoection is not required by regulation. However, we will require an Atil to verify any inspection required by 10 CFR 50.55a at Sequoyah Unit tios. I and 2 and all other commercial nuclear power facilities which are licensed to this applicant.
1674 039