ML20207E922
| ML20207E922 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/22/1986 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8701050202 | |
| Download: ML20207E922 (5) | |
Text
, _.
PHILADELPHIA ELECTRIC COMPANY 23O1 M ARKET STREET P.O. BOX 8699 PHILADELPHIA PA.19101 (21518414000 December 22, 1986 Docket No. 50-278 l
Mr. Daniel R. Muller BWR Project Directorate #2 Division of BWR Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
SUBJECT:
Peach Bottom Atomic Power Station Unit 3 Replacement of Piping on RHR and Recirculation Systems
REFERENCE:
Letter, M. J. Cooney, PECo, to D.
R. Muller, USNRC dated October 8, 1986
Dear Mr. Muller:
In the referenced letter, Philadelphia Electric Company (PECo) requested relief from a Confirmatory Order requiring a Cycle 7 mid-cycle inspection of five welds on Peach Bottom Unit 3.
On November 24, 1986 representatives of PECo, NRC and General Electric Company met in Bethesda, MD to discuss this relief request in more detail.
As a result of the NRC technical staff review of our requests, we have been asked to provide the additional information for Peach Bottom Unit 3 contained in this letter.
The four requests are restated below followed by our responses.
Question 1:
Describe the program for further improvement in Peach Bottom water chemistry as stated in your submittal dated October 8, 1986.
Response to Question 1:
In the past year, an Engineering / Electric Production Chemistry Overview Committee has been formed to review the plant chemistry at each of our nuclear plants to 8701050202 861222
\\
1 0 pna ADOCK 0500027G
[0 g
PDR g
Mr. Daniel R. Muller December 22, 1986 Page 2 1
identify operational problems and ensure their timely resolution.
The committee is made up of plant and engineering personnel directly involved with plant chemistry.
In addition, outside consultants are used to provide additional expertise in certain areas.
As a result of this committee's work, a number of improvements have been initiated and others are being investigated.
We have installed new conductivity instrumentation which is more accurate than the original equipment.
In addition, studies were performed to identify the cause of the higher than expected reactor water conductivity which was being experienced on Unit 3 prior to November.
Although the reactor water conductivity was below the Action Level 1 BWR chemistry guideline, we believed that further improvement was possible.
The median reactor water conductivity for 1986 (through October) was 0.23 umhos.
Our studies and the data obtained from the improved conductivity instrumentation indicated the possibility of small condenser leaks.
During a plant startup in November 1986, our leak detection method was reviewed and improvements were made to provide increased sensitivity.
As a result of these changes, additional condenser leaks were identified and repaired.
This resulted in improved reactor water chemistry.
The average conductivity has dropped to less than 0.12 umhos for the period November 22, 1986 to December 10, 1986.
We believe that Unit 3 conductivity will continue to be low for the remainder of the fuel cycle.
We plan to continue investigating the following items which will reduce the frequency, magnitude and duration of chemistry transients and will implement corrective actions as appropriate:
1.
A means to reduce the number of resin intrusion incidents.
2.
The need for a more effective means of condenser leak detection.
3.
The need for retubing of the condenser.
4 In addition to the chemistry review committee, a corporate level chemistry overview committee has recently been formed.
This committee is staffed by management personnel from both the Electric Production Department (now Nuclear Operations) and the Engineering and Research Department as well as outside consultants.
Its primary goal is to ensure that the collective knowledge of the industry as it pertains to
Mr. Daniel R. Muller December 22, 1986 Page 3 chemistry issues is appropriately factored into our operations.
Question 2:
Has the implementation-of the April 1985 BWR Water Chemistry Guidelines been completed?
When do you plan to implement the revised guidelines to be published early 1987?
Identify any exceptions to the guidelines mentioned above.
Response to Question 2:
Philadelphia Electric Company is committed to operate our Peach Bottom units within the chemistry control limits of Section 3 of the 1985 BWR Water Chemistry Guidelines.
Plant specific power operation action level values have been established using the guidelines and are contained in a PORC approved procedure.
These action levels are equal to or more stringent than those contained within the guidelines.
Action statements have also been specified.
These action statements allow plant supervision to assess the nature, the duration, and possible consequences, and to factor in the experience gained from past transients in determining their corrective action.
As an example, significant information has been obtained from the crack arrest verification system and ion chromatographs which indicated that some transients, due to their short duration and nature of impurities, cause very little damage to the primary coolant piping.
Our chemistry control program also differs from the EPRI BWR water chemistry guidelines in that achievable values are determined by the plant staff but are not documented in a procedure.
We believe that implementation of this plant specific chemistry control procedure meets the intent of the EPRI BWR water chemistry guidelines.
Philadelphia Electric Company participated in the development of the revised chemistry guidelines.
Within 90 days of the publication of the revised guidelines, we will complete an assessment of the revisions to determine what changes, if any, are required to our chemistry program.
At that time, we will develop an
t o
Mr. Daniel R. Muller December 22, 1986 Page 4 action plan to implement these changes on an expedited schedule.
Question 3:
What is the schedule for implementation of hydrogen water chemistry on Peach Bottom Units 2 and 3?
Response to Question 3:
i Hydrogen water chemistry is scheduled for implementation during the next refueling outage on each unit.
The Unit 2 refueling outage is scheduled for the Spring of 1987 and the Unit 3 refueling outage is scheduled for the Fall of 1987.
The detailed design of the necessary system and equipment has been virtually completed and procurement activities are ongoing.
Control room modifications associated with implementation of hydrogen water chemistry require a refueling outage for completion.
Our ability to implement hydrogen water chemistry is also contingent upon NRC staff review and approval of:
(1) a Technical Specification change to modify the main steamline radiation monitor setpoint, and (2) approval of the design of the liquid hydrogen and oxygen storage systems and equipment.
Submittals for these changes will be made in the near future.
Question 4:
What is the schedule for replacing all the piping and safe ends which are susceptible to-IGSCC?
Response to Question 4:
Peach Bottom Unit 3 is scheduled for a major refueling and pipe replacement outage beginning in Fall 1987.
This outage will be similar to that required for the pipe modification of Unit 2.
The duration of the activity is expected to be 48 weeks.
During this outage, the recirculation safe ends, jet pump instrumentation penetration seals and all IGSCC susceptible piping inside the primary containment will be replaced with materials which are resistant to IGSCC.
i
'O Mr. Daniel R. Muller December 22, 1986 Page 5 Should you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours,
.W WY-cc:
Dr. T.
E. Murley, Administrator, Region I, USNRC T. P. Johnson, Resident Site Inspector 1
l l
i 4
1 I
i i
I
,7-~_-,_m,--
,~m__,.m,,,
,_-,,.m,,.-
-