ML20209E728
| ML20209E728 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 04/22/1987 |
| From: | Gallagher J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Butler W NRC |
| References | |
| CON-#287-3300 OL, NUDOCS 8704300106 | |
| Download: ML20209E728 (4) | |
Text
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i PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA PA.19101 121st e41 sool g
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April 22, 1987 Docket No. 50-352 Mr. W. R. Butler BWR Project Directorate #4 Division of Boiling Water Reactor Licensing U.S. Nuclear Regulatory Cmmission Attention: Docunent Control Desk Washington, DC 20555
SUBJECT:
Limerick Generating Station Unit 1 Removal of Reactor Head Spray and Vent Piping and Vessel Stud Detensioning 1
REFERENCES:
a) Letter, V. S. Boyer (PECo) to H. R. Denton (NRC),
Dated Septerrber 21, 1984 b) Letter, J. W. Gallagher (PECo) to W. R. Butler (NRC),
Dated March 19, 1987
Dear Mr. Butler:
Limerick Generating Station Unit 1 License Condition 2.C.14 states that until the Standby Gas Treatment System (SGTS) is connected to the refueling area, the Licensee shall not remove the RPV head prior to NRC staff review and approval.
License Condition 2.C.14 references Section i
6.2.3 of SSER-2 and SSER-3 which states that until the SGTS is connected to the refueling area, operations involving removal of the Primary Containment head as well as the RPV head after initial 4
criticality are prohibited without specific prior NRC approval. This same condition is contained in reference a).
Reference b) requested NRC approval to remove the drywell head prior to connection of the SGTS to the refueling floor. With approval of that request, our plans for the upcoming refueling outage call for removal of the RPV head spray and vent piping and detensioning the RPV head studs prior to connecting the SGTS to the refueling area.
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A Safety Evaluation has been performed which concludes that the SGTS need not be connected to the refueling area while removing the RPV hMMi head spray and vent piping and detensioning the RPV head studs for ;he l
following reasons:
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Retroval of the RPV head spray and vent piping and 0
i detensioning the the RPV head studs can not result in fuel i\\s\\
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8704300106 870422 PDR ADOCK 05000352 P
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damage requiring the use of the SGTS to control the release of radiation.
SGTS is not required by the Technical Specification Limiting Conditions for Operatson to be operable during removal of the RPV head spray and vent piping and detensioning the RPV head studs.
There are no Technical Specification Limiting Conditions for Operation requiring that the refueling area secondary containment Integrity be verified prior to perfonning the aforementioned operations. Refueling area secondary containment integrity will be verified prior to handling irradiated fuel, perfonning core alterations, or operations with the potential to drain the vessel as required by
)
Technical Specification Section 3/4.6.5.1.2 j
(
Acceptable limits on primary coolant radioactivity prior to initiating the removal of the RPV head spray and vent piping and detensioning the studs can be determined based on the LGS Technical Specification Instantaneous Limits (3.11.2).
Current primary coolant activity is approximately
-g 1 x 10 uCi/gn (I-131 dose equivalent.) Conservative ca:culations Indicate that a coolant activity limit of 3.65 Cl or 0.02 uCI/gm (I-131 dose equivalent), more than two orders of magnitude above the current coolant activity, will ensure that offsite doses will remain below Technical Specification ilmits. The calculation on which this limit is based is attached (Attachment I).
Prior to removal of the piping and detensioning the studs, coolant activity will be verified to be below the calculated limit.
Immediately upon breaching the flanged connections between the 6" RPV head spray and 4" vent piping and the RPV head, health physics surveys are taken to ensure excessive radioactivity will not be released when the piping is completely removed. As soon as the piping is removed, blank flanges or HEPA filters are installed on the two RPV head flanges to inhibit the direct ccmnunication between the reactor coolant and the refueling area. The above steps are not unique to the first refueling outage. They are part of the standard procedures to be followed during any refueling outage, as shown in the refueling outage flow diagram, FSAR Figure 9.1-13.
The removal of the RPV head spray and vent piping and detensioning the RPV head studs will be perfonned in accordance with the appropriate approved plant procedures to assure that the assunptions, actions, and.
conclusions presented in the above discussions remain valid.
Based on the above considerations, it is not necessary to have the SGTS connected to the refueling area prior to the removal of the RPV head spray and vent piping and detensioning the RPV head studs.
4.
In order to conform with the intent of license condition 2.C.14, Philadelphia Electric Company requests NRC approval to remove the RPV head spray and vent piping and detension the RPV head studs prior to the connection of SGTS to the refueling floor.
If you have any questions or require additional information on this subject, please do not hesitate to contact us.
In accordance with Section 170.12 of the Cmmission's regulations, enclosed is Philadelphia Electric Company's check in the amount of
$150.00 to cover the filing fee.
1 1
Very truly yours, l-N0'f j
CWW/cb/04028709 Attachment Copy to: Addressee W. T. Russell, Regional Administrator, USNRC, Region I E. Kelly, Senior Resident Site Inspector See Attached Service List i
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l ATTACif1ENT I Technical Speci.fication 3.11.2 Instantaneous Limits Definitions:
X/Q = dispersion factor BR
= breathing rate D.F. = dose conversion factor D
= maximtm permitted dose Dose = (1500 mr/yr) (1 yr./8760 hr.) (8 hr.)
r 1.37 mr D
= (ci) (x/Q) (BR) (D.F.), ass.sning an 8 hr. release
-5 37,3 per EROL Table 7.1-6 (8 hr. av.)
Where x/Q = 7.3 x 10 GR
= 1.17 x 10~ m /s per R.G. 1.109 9
D.F. = 4.39 x 10 mrem /CI per R.G. 1.109 D
= 1.37 me CI
= (Coolant Activity) (Release Fraction)
CA (RF)
Where: RF = 0.01 per R.G. 1.25 CA D
1.37 (RF) (x/Q) (BR) (DF)
(0.01) (1.17 x 10') (7.3 x 10') (4.39 x 10'),
= 3.65 Ci
-2
- 2 x 10 uCl/gm WJB/pdO3208709