ML18052B450
| ML18052B450 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/19/1988 |
| From: | Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML18052B451 | List: |
| References | |
| NUDOCS 8801250047 | |
| Download: ML18052B450 (3) | |
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consumers Power POW ERi Nii M.ICHlliAN'S PROliRESS General Offices:
1945 West Parriall Road, Jackson, Ml 49201 * (517) 788-1636 January 19, 1988 Nuclear Regulatory Cormnission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DBR PALISADES PtANT -
I TECHNICAL SPECIFICATIONS ~RANGE REQUEST -
SECONDARY WATER CHEMISTRY/
Kenneth W Berry Director Nuclear licensing Consumers Power Company is requesting changes be made to the Technical Specifications to delete the secondary water chemistry limits in specification 3.18 along with surveillance requirements in Table 4.2.1 and replace them with program requirements in the administrative section of the specifications.
These changes are requested so that Palisades can implement use of boric acid addition to the secondary steam generator water to minimize steam generator corrosion and tube denting.
The proposed changes will result in conformance with the Standard Technical Specifications (NUREG-0452 rev. 4 for Westinghouse PWRs).
The addition of boric acid to secondary water has been shown at several other PWRs to be beneficial in arresting the steam generator tube denting mechanism which presently is the most prevalent form of damage to the Palisades steam generator tubes.
Prior to 1988, the addition of boric acid to the secondary side of the steam generators was viewed as non-beneficial.
This position was based on the presence of a large porous sludge pile on the steam generator tube sheets. It was thought that the use rate of boric acid would be higher than necessary and not very beneficial since the effects of the boric acid would be dampened considerably due to absorption in the sludge pile.
Due to the tube leak on December 4, 1987, and the removal of a large amount of the sludge pile, the addition of boric acid to the secondary side of the generators becomes a low cost measure to mitigate denting.
Approximately 4,400 pounds of sludge were removed from the steam generators during a just completed sludge lancing procedure.
The performance of future sludge lancing efforts will be evaluated prior to each refueling outage.
Startup from the present outage provides the best opportunity for adding boric
_acid and starting the process of arresting the corrosion process.
EPRI 00.012soo47.* aeo11~--i---:-:-"l
. PDR. ADOCK 05000255 I
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.. J OC01'88-0012-NL04
~uclear Regulatory Commission Palisades Plant TSCR - Secondary Water Chemistry January 19, 1988 NP-3278, Evaluation of Field Applications of Boric Acid in PWR Steam Generators describes this process.
The EPRI report suggests that the boric acid reacts with the corrosion product Fe30 4 in the crevice.to form several iron-boron compounds which tend to coat tfie crevice and thereby restrict the corrosion reaction.
2 Our assessment of the ECT data from the 1987 leaking tube indicates a form of damage similar to that observed and analyzed in 1983/1984.
The progression of such damage appears to be related to local denting.
The 1987 forced outage clearly indicates that there is the local (non-pervasive) progression of intergranular corrosion (IGC), contrary to the conclusion reached in 1984.
It is therefore imperative to implement prudent actions immediately to prevent future plant reliability losses, and-potential safety system challenges.
In order to implement the addition of boric acid to the secondary water, Consumers Power Company requests the NRC to take prompt action on this Technical Specifications Change Request in accordance with the provisions in 10CFRS0.91(a)(6) for exigent circumstances.
The present schedule has the Plant on-line on January 29, 1988.
The present Technical Specifications, which we are asking to be deleted, require the steam generator blowdown chemistry to be within their limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of synchronization of the unit.
In order for us to institute the boric acid addition during the return to power operation an approved amendment would be required by February 1, 1988.
The urgency of this request is based upon the need for a low power level (about 35% power) to permit "soaking" at elevated boric acid concentration levels.
Following the initial soak, the concentration of boric acid, is diluted to 5-10 ppm.
Neither of these concentration levels will permit compliance with the pH values of the existing Technical Specifications.
In the event that this change request is not approved, and the plant must operate without a mechanism in place which could arrest the ongoing corrosion process.
Consumers Power Company has been evaluating the use of boric acid secondary treatment for several years.
In addition, a February 1987 evaluation by Westinghouse provided recommendations to initiate boric acid treatment in the Palisades Steam Generator.
This current outage, which resulted from a Steam Generator tube leak yielded information that permitted us to conclude that tube damage was more significant than previously thought.
The outage, also permitted us the opportunity to attempt tube sheet sludge lancing that proved very effective.
Prior to this current outage, we had scheduled to attempt sludge lancing efforts during the next maintenance outage which had been scheduled for Spring 1988.
The events of the present unforeseen outage have therefore led us to make this request for exigency.
We understand this change request may not meet the requirements for exigent circumstances in 10CFR50.91(a)(6), however, we believe you will agree that prompt action is prudent with regard to Steam Generator reliability and, accordingly, we ask that exigent procedures be applied to this change request review and approval process.
OC0188-0012-NL04
e Npclear Regulatory Commission Palisades Plant TSCR - Secondary Water Chemistry January 19, 1988 A check in the amount of $150.00 is enclosed as required by 10CFR170.12.
Kenneth W Berry Director, Nuclear Licensing CC Administrator, Region III, NRC NRC Resident Inspector - Palisades Attachment OC0188-0012-NL04 3