ML15223A790
| ML15223A790 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/11/1982 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 8203220522 | |
| Download: ML15223A790 (4) | |
Text
MARCI 1 1 582 DISTRIBUTION:
ORB#4 Rdg TSpeis Docket File DEisenhut SDiab NRC PDR PWagner HOrnstein L PDR RIngram EBlackwood Dockets Nos. 50-269, 50-270 OELD and 50-287 AEOQ IE' ACRS -10 Gray File Mr. William 0. Parker, Jr.
Vice President - Steam Production MARI M)$2 Duke Power Company saam Mm P. 0. Box 33189 422 South Churh Street Charlotte, North Carolina 28242
Dear Mr. Parker:
We have reviewed your July 24, 1981 letter regarding low temperature overpressure protection and information previously submitted on this subject and find that insufficient information is available for us to complete our review.
Accordingly, we have enclosed a detailed list of the remaining NRC concerns which more fully describi what information is required.
We are continuing our review of the pertinent information provided in your January 12, 1932 submittal concerning Appendix G information and will advise you in the near future2Yf additional infor mation is also requftad in this area.
In order for us to complete our review in our scheduled time frame, we request that you respond to the enclosed questions within 30 days of your receipt of this letter.
Since this request for information is related solely to the Oconee Nuclear Station, fewer than ten respondents are affected; therefore, OMB clearance is not required under P. L.96-511.
Sincerely, W ORIGISAL SIGNE= tE John F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing
Enclosure:
Request for Additional Information cc w/enclosure:
See next page 6203220522 820311 PDR ADOCK 05000269 P
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Duke Power Company cc w/enclosure(s):
Mr. William L. Porter Duke Power Company P. 0. Box 33189 422 South Church Street Office of Ihtergovernmental Relations Charlotte, North Carolina 28242 116 West Jones Street Raleigh, North Carolina 27603i Oconee County Library 501 West Southbroad Street Walhalla, South Carolina 29691 Honorable James M. Phinney County Supervisor of Oconee County Walhalla, South Carolina 29621 Mr James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission, Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Regional Radiation Representative EPA Region IV 345 Courtland Street, N.E.
Atlanta, Georgia 30308 William T. Orders Senior Resident Inspector U.S. Nuclear Regulatory Commission Route 2, Box 610 Seneca, South Carolina 29678 Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 220, 7910 Woodmont Avenue Bethesda, Maryland Z0814 Manager, LIS NUS Corporation 2536 Countryside Boulevard Clearwater, Florida 33515 J. Michael McGarry, III,-Esq.
DeBevoise & Liberman 1200 17th Street, N.W.
Washington, D. C. 20036
Enclosure REQUEST FOR ADDITIONAL INFORMATION
- 1. The Branch Technical Position (SRP 5.2.2/RSB 5-2) requires the Oconee Units 1, 2 and 3 overpressure protection systems (OPS) to prevent exceeding the applicable Technical Specifications and 10 CFR 40 Appendix G limits. In your analysis and system description, you use 550 psig as the low temperature PORV setpoint and as the value that RCS pressure is allowed to reach prior to any credited operator action. Does the 550 psig setpoint provide adequate assurance that the Appendix G curve limits will not be exceeded for all temperatures below 408 0F (the minimum pressurization temperature)?
- 2. The OPS is required to function assuming any single active component failure.. The Oconee overpressure protection system does not meet this criterion for the case of inadvertent actuation of the high pressure injection (HPI) system with the PORV failing closed. You mentioned in your submittals a proposed system to trip the HPI pumps during a pressure transient and several administrative controls that are used to prevent an inadvertent HPI injection. In it's February 2, 1978 letter, the staff stated that this concept is acceptable provided the system meets the design criteria, and adequate controls to prevent the event are included in the plant Technical Specifications.
- a. Provide a copy of all Technical Specifications (TSs) that deal with this subject or propose appropriate revisions.
List all procedural and administrative controls used during HPI system tests and RCS hydrostatic tests to prevent violating Appendix G limits.
- c. Could the HPI isolation valves HP-26 and HP-27 be manually opened locally? Would the control room operators have any indication of this?
- d. What is the status of the installation of the proposed system mentioned a
bov e?
- 3. Relative to the OPS.testing, please respond to the following:
- a. How is the PORV and its control circuitry functionally tested?
- b. At what frequency are these tests performed?
c How do you ensure that these valves actually open during testinq?
- d. Provide a copy of all TSs that deal with this subject or propose appropriate revisions.
- 4. The Reactor Systems Branch position RSB 5-2 requires an alarm to alert the operator to properly enable the overpressure protection system at the correct plant condition during cooldown. If the system is not properly enabled, with the PORV isolation valve open and the PORV low setpoint selected by the correct position of the key-lock switch, it will not function to mitigate an overpressure event.
How does Duke Power Company meet this requirement at Oconee Units 1, 2, and 3?
-2
- 5. RSB 5-2 requires that an alarm must be provided to alert the operator that a pressure transient is occurring. You take credit for operator.action to mitigate a pressure transient for all analyzed events when-a failed closed PORV is considered. No credit can be taken for operator action until 10 minutes after -the operator 1s aware that a pressure transient is in progress For the most severe event that you analyzed, what audible alarm will alert the operators that a pressure transient is occurring.(alarmsassociated,with the PORV cannotbe used because tis assumed failed closed)? We require that acceptable technical specification -'*
changes or system modifications be.proposed to increase your calculated operator time from 4.4 minutes to at least 10 minutes.
- 6. What training has been conducted at Oconee to make the operating personnel aware of overpressure incidents at other facilities and possible over pressure situations at Oconee? How do you ensure that an emphasis is placed on this probleem during your licensing and retraining programs?
- 7.
Provide current P&IDs of the overpressure protection system.
- 8.
The administrative controls you use to ensure against the inadvertent opening of an HPI valve are not put into use until RCS temperature drops to 2500F during cooldown and they are removed once temperatures reach 250oF during system heatup. This leaves the time spent between 250oF and 4080F (the minimum pressurization temperature) where.an inadvertent valve opening or a valve malfunction could result in a pressure transient that could exceed Appendix G curve limit. Address this tssue.