ML18066A882

Forwards Response to 970116 Meeting Questions Re Emergency Escape Airlock TS Change Request & Exemption

ML18066A882
Person / Time
Site:	Palisades
Issue date:	02/20/1997
From:	Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9702250098
Download: ML18066A882 (7)

Text

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consumers Power Thomas C. Bordine Manager, Licensing PllWERINli MIClllliAN"S l'ROliRES5 Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 February 20, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT RESPONSE TO MEETING QUESTIONS - EMERGENCY ESCAPE AIRLOCK TSCR AND EXEMPTION In a meeting on January 16, 1997, several questions were asked regarding our Technical Specification Change Request and Exemption Request dated January 10, 1996. These requests would allow the modification of the testing requirements for the Palisades Emergency Escape Airlock. The attachment provides our response to those questions.

SUMMARY

OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.

Thomas C. Bordine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment

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9702250098 970220 PDR ADOCK 05000255 p PDR A CMS' ENER6YCOMPANY

ATTACHMENT CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 RESPONSE TO MEETING QUESTIONS EMERGENCY ESCAPE AIRLOCK TSCR AND EXEMPTION 5 Pages

RESPONSE TO MEETING QUESTIONS EMERGENCY ESCAPE AIRLOCK TSCR AND EXEMPTION NRC REQUESTED INFORMATION

( 1) How old are the seals on the doors, ie, when were they manufactured; and when were they installed on the doors?

CPCO RESPONSE (1) The manufacturing dates for the seals are presented as "cure" dates by the vendor on the Certificates of Conformance. Three of the present seals have cure dates of the 3rd quarter of 1996. One of the present seals has a cure date of the 2nd quarter of 1992.

The installation of the present seals was completed on November 30, 1996, during the 1996 Refueling Outage. Of the seals which were replaced, the ones with the longest service life were installed on June 30, 1993.

See Table 1.

NRC REQUESTED INFORMATION (2) What is the shelf life of these seals, both according to the manufacturer, and according to the licensee's engineers (if different from the manufacturer's numbers)?

CPCO RESPONSE (2) The vendor's Certificates of Conformance provided a shelf life of 2 years from the cure date.

Palisades initially assigned a 2 year shelf life to the seals. Palisades shelf life program allowed personnel to evaluate and extend shelf life in accordance with plant procedures or practices. The shelf life of the seal with a cure date of the 2nd quarter of 1992 was evaluated for extension on August 31, 1994. This evaluation resulted in an extension of the shelf life to January 1, 1997.

See Table 1.

2 NRC REQUESTED INFORMATION (3) What is the recommended service life for these seals? That is, how long should they be in service before they should be replaced? Again, both the manufacturer's and the licensee's numbers.

CPCO RESPONSE (3) The vendor's Certificate of Conformance provided a service life termination of the 2nd quarter of 1997 for the seal with a cure date of the 2nd quarter of 1992. The vendor's Certificate of Conformance provided a combined shelf and service life termination of the 3rd quarter of 2001 for the seals with a cure date of the 3rd quarter of 1996.

Palisades did not assign a service life to the seals but the applicable preventive maintenance activity recently added a replacement frequency of every three years. Routine testing and inspection or other circumstances may dictate seal replacement prior to the three years service life.

See Table 1.

NRC REQUESTED INFORMATION (4) Is there a maximum service life number, presumably longer than the recommended life? Again, provide numbers from both sources.

CPCO RESPONSE (4) The vendor did not assign a maximum service life for the seals. However, for the seals with a cure date of the 3rd quarter of 1996, the vendor's Certificate of Conformance provided a combined shelf and service life termination date of the 3rd quarter of 2001. For the seal with a cure date of the 2nd quarter of 1992, the vendor's Certificate of Conformance provided a service life termination date of the 2nd quarter of 1997.

Palisades did not assign a maximum service life to the seals. As stated in our response to Request No. 3, Palisades intends to replace them every three years, in accordance with a preventive maintenance activity.

See Table 1.

3 NRG REQUESTED INFORMATION (5) For all the "lives" above, provide the figures applicable when the seals were made or purchased in addition to currently applicable figures.

CPCO RESPONSE (5) The vendor's Certificates of Conformance provided a shelf life of 2 years from the cure date for all of the seals currently installed. Palisades' shelf life programs that were in place for the seals with a cure date of the 2nd quarter of 1992 and the 3rd quarter of 1996 allowed appropriate Palisades personnel to evaluate and extend shelf life in accordance with plant procedures or practices.

Palisades initially assigned a 2 year shelf life to all of the seals. The shelf life of the seal with a cure date of the 2nd quarter of 1992 was evaluated for extension on August 31, 1994. This evaluation resulted in an extension of the shelf life to January 1, 1997.

The vendor's Certificate of Conformance provided a service life termination of the 2nd quarter of 1997 for the seal with a cure date of the 2nd quarter of 1992. The vendor's Certificate of Conformance provided a combined shelf and service life termination of the 3rd quarter of 2001 for the seals with a cure date of the 3rd quarter of 1996. No different maximum service life was assigned by the vendor.

Palisades does not specifically assign a service life or a maximum service life to the seals. When seals were procured in 1992, seal replacement was based on leak rate test results and inspections. When seals were procured in 1996, seal replacement was based on leak rate test results and inspections with the additional intent of the preventive maintenance program that seals would not remain in service more than 2 fuel cycles (approximately 3 years).

See Table 1.

NRG REQUESTED INFORMATION (6) What does the manufacturer say about "fluffing" and "grease contact tests?"

Were these practices recommended or allowed when the airlock was designed, built, installed, or when the plant began operation? Does fluffing damage the seals so that they Jose resiliency?

4 CPCO RESPONSE (6) The vendor does not have a position for or against "fluffing." "Fluffing" is a term that has been used to describe the seal contact adjustment to allow the seal to relax from a more compressed condition. Palisades uses seal shimming, latch bracket adjustment and "fluffing" as seal contact adjustment techniques. "Fluffing" is only effective for minor seal contact adjustments.

The vendor recognizes and approves of grease contact tests as an appropriate means of evaluating and ensuring seal contact.

Palisades has not been able to find any information which would indicate these practices were either prohibited or recommended when the airlock was designed, built, installed or the plant began operation. Likewise, there has been no indication that these practices should be prohibited or that they were recommended since the plant began operation.

Palisades and the vendor do not believe that "fluffing" damages the seals or degrades the seals in such a way that they loose resiliency. Leakage rate testing on the Palisades' Personnel and Emergency Escape Airlocks indicate that there is no loss of resiliency due to "fluffing" this type of seal material.

Unrestrained between-the-seals pressure testing is very sensitive to seal degradation due to the lifting forces applied to the doors. Between-the-seals testing is performed on the Personnel Air Lock which uses the same type of seals. "Fluffing" has been used as a seal contact adjustment technique on the Personnel Air Lock for more than 10 years and the between-the-seals pressure tests have not provided any indication that this damages the seals.

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• 5 11 Table 1 : Emergency Escape Airlock Seal Lives" Vendor "Lives" Palisades "Lives" Seal Cure I I Installation Date Shelf End Date Service End Date I Shelf End Date I Service 4 Date I I 1 2092 2 yrs. 2094 5 yrs. 2097 2 yrs. 2 1/1/973 Not 11/30/96 assigned 2 3096 2 yrs. 1 3098 5 yrs. 1 3001 2 yrs. 2 3098 Not 11/30/96 assigned 3 3096 2 yrs. 1 3098 5 yrs. 1 3001 2 yrs. 2 3098 Not 11/30/96 assigned 4 3096 2 yrs. 1 3098 5 yrs. 1 3001 2 yrs. 2 3098 Not 11/30/96 assigned 1 -- Shelf Life and Service Life combined = 5 yrs.

2 -- Initial Shelf Life assignment, may be extended by evaluation 3 -- Extended by evaluation on 8/31/94 to 1/1/97 4 -- Service life not assigned by Palisades, Service Life based on leak test results and inspection. Preventive maintenance activity intent is to replace seals every 3 yrs.