ML19209A378
| ML19209A378 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 08/24/1979 |
| From: | Groce R YANKEE ATOMIC ELECTRIC CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-17, WYR-79-93, NUDOCS 7910030679 | |
| Download: ML19209A378 (4) | |
Text
.5 Telephone 617 366-9011 rwx 710-390-0739 YANKEE ATOMIC ELECTRIC COMPANY M'i'93 20 Turnpike Road Westborough, Massachusetts 01581 KEE August 24, 1979 United States Nuclear Regulatory Commission Office of Inspection and Enforcement Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention:
Mr. Boyce H. Grier, Director
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) USNRC Circular 76-06 dated November 24, 1976 (c) YAEC letter, D. E. Vandenburgh to USNRC Region I dated December 22, 1976 (WYR 76-130)
(d) YAEC letter, D. E. Moody to USNRC Region I dated September 23,1977 (WYR 77-91)
(e) USNRC letter to YAEC dated July 26, 1979 I&E Bulletin 79-17
Dear Sir:
Subject:
Response to I&E Bulletin 79-17 The following information is being submitted in response to UShTC-I&E Bulletin 79-17.
The responses are numbered corresponding to the bulletin paragraph numbers.
Paragraph 1 The safety related stainless steel piping systems at Yankee Rowe which contain stagnant oxygenated borated water are the low pressure safety injection system, high pressure safety injection system, shutdown cooling, loop fill line, and pressurizer decon spray lite systems.
Paragraph 1.a The following is a break down of the hydrotests and visual and volumatric examinations performed as a response to Circular 76-06:
Paragraph 1.a.1 Hydrotests were performed as directed by Circular 76-06 on the following systems. The hydropressure was system operating pressure.
Loop Fill Line from Charging Pumps to December 30, 1976 091
% 4 SI Header Pressurizer Decon Spray Line December 30, 1976 910080
,a United States Nuclear Regulatory Commission August 24, 1979 Attention: Office of Inspection and Enforcement Page Two LPSI/ Accumulator from S1 MOV1 to 2nd ISO December 30, 1976 Valve of Loops HPSI from Junction of Recire Line to 2nd December 30, 1976 ISO valve of Loops Shutdown Cooling System April 21, 1977 In all tests, no evidence of leakage was detected. The details of these examinations are on file at the plant site.
The following welds were examined volumetrically or with surface exam techniques. The welds were selected on the basis of access and high stress configuration, i.e. pipe to fitting welds.
Shutdown Cooling UT 2 welds Core XII - XIII Refuel Loop Fill / Safety Injection UT 11 welds Pressurizer Decon Spray PI 2 welds Loop Fill - (2")
PT 2 welds No abnormalities of any kind were observed.
The volumetric examinations were performed using Yankee Atomic Procedure YA-'UT-10.
This procedure complies with Appendix III of the Summer 76 Addenda to ASME Section XI 1974 Edition. Acceptance criteria are based on the acceptance criteria of EF, BJ, IWB 3000, of the same edition and addenda. The exception to this procedure were a scan area of 6"T" on either side of the weld where accessible.
The examination results shewed no evidence of unacceptable indications. There was no corrective action taken.
Paragraph 1.b The systems described in Paragraph I with the exception of the pressurizer decon spray line are filled with water originating in the safety inj ection tank.
The safety injection tank is filled from a blend of demineralized water from the primary water storage tank, TK-39, and 12% by weight of boric acid from the boric acid storage tank.
Normal water chemistry for the safety injection tank is:
1091 305 pH no specification, but follows the pH of boric acid solutions.
For 2300 ppm boron solutions, pH is typically 4.9.
Boron 2200-2400 ppm boron as boric acid.
Oxygen Saturated. Typically 3-5 ppm oxygen
United States Nuclear Regulatory Commission August 24, 1979 Attention: Office of Inspection & Enforcement Page Three at normal safety injection tank temperctures of 50-750F.
Chloride 0.15 ppm Fluoride 0.15 ppm Conductivity 5 umhos/c::.
Safety injection tank contents are periodically purified by passage through an ion exchange resin bed and/or a particulate filter.
Certain portions of the systems described in paragraph 1 are routinely recirculated during surveillance testing.
Chemistry analyses of stagnant, oxygenated, borated water samples were performed to reaffirm that they were typical of the bulk safety injection water chemistry. The results are tabulated below.
pjl Baron / ppm Oxygen / ppm Cl / ppm F / ppm Safety Injection 5.0 2300 4.0 0.1 0.1 Tank bult water etx analyses of 5.0-6.0 2060 3-5 0.1 0.1 scagnant, borated thru oxygenated water 2560 samples from high and low pressure safety injection lines, shutdown cooling, low pressure accumu-lator tank.
(Range of six analyses)
Paragraph 1.c Yankee Rowe was ccustructed before preservice examination requirements.
When we became involved in an ISI program, only Class 1 piping was required to be examined; therefore no preservice data exists for the Class 2 or 3 piping. Construction inspection was based on the 1955 edition of ANSI B31.1 and Stone & Webster Specifications. The Stone & Webster Specifications provided the additional requirement of radiography on 20% of fusion welded butt-joints in all alloy and non-ferrous piping material when not governed by the applicaole codes.
1091 306 Paragraph 1.d In 1966/67 a leak was detected in an elbow to pipe weld off the Boric Acid Mix Tank. The system was not classified as a safety system at that
United States Nuclear Regulatory Commission August 24, 1979 Attention: Office of Inspection and Enforcement Page Four time. A repair was affected on the weld and the system returned to service.
No other evidence of any weld failures has occurred through the operating history of the plant. No additional documentation is available on this repair. This report is submitted in compliance with item 5 of Bulletin 79-17.
Additional information is also being submitted concerning paragraph 2 of the subject Bulletin and is as follows.
Paragraph 2 Beginning on September 8,1979, Yankee will shutdown for a one (1) week maintenance outage. During this time, Yankee will begin the work _ described in paragraph 2 and will perform the visual examinations as required by paragraph 2.a.
In ad(ition ultrasonic examinations as required by and to the extent of paragraph 2.b will be conducted. The examinations will be performed using a procedure developed for detection of IGSCC. This procedure uses as its basis the EPRI/SwRI procedures for detection of IGSCC including dual element, zone discriminating search units. The procedure also complies with ASME Section XI Appendix III.
We will perform liquid penetrant exams of socket welds or welds which cannot be scanned ultrasonically using at least a 1 and h vee path. This scan must include the base metal " from the pipe I.D.
A 2 " vee" path shall be considered acceptable from one side of a pipe to fitting weld when it can be shown the exam area is covared.
If you have any questions, please contact Jack Lance at Yankee Atomic Electric Company, Westboro, Massachusetts (617) 366-9011 extension 3186.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY M
W%
Robert H. Groce Licensing Engineer JJL/smw 1091 307