ML20237A253
| ML20237A253 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/01/1987 |
| From: | Andrews R OMAHA PUBLIC POWER DISTRICT |
| To: | Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20237A233 | List: |
| References | |
| LIC-87-815, NUDOCS 8712140360 | |
| Download: ML20237A253 (3) | |
Text
{{#Wiki_filter:_ _ _ _ __ _ _ _ _ _ - - _ _ _ _ D b$b i i += Ornaha Public Power District 1623 Harney Omaha, Nebraska 68102-2247 402/536-4000 December 1, 1987 {(9 f } l_IC-87-815 P~ [;f DEC - 41987 ? h Mr. Robert D. Martin d Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011
Reference:
Docket No. 50-285
SUBJECT:
Enforcement Discretion
Dear Mr. Martin:
In a verbal request on December 1,1987, the Omaha Public Power District, via the NRC Senior Resident Inspector, asked that enforcement discretion be oursued. The enforcement discretion concerns one of the the containment purge valves. Technical Specification 2.6(1)(e) requires that the containment purge isolation valves be locked closed unless the reactor is in a cold or refueling shutdown condition. The valves are 42" butterfly valves. Technical Specification 3.5(3)(c) requires the surveillance testing of these valves prior to leaving cold or refueling shutdown, but in no case longer than nine months. On November 30, 1987, while performing the leak test for penetration M-87 (associated with valves PCV-742A and PCV-742B) it was determined that measured leakage was in excess of acceptance criteria. Immediate corrective action was taken to determine if the leakage was associated with the inboard or outboara valve. A containment entry was made and the seal on the inboard valve exhibited slight leakage; thus, it was adjusted slightly and then snoop checked. No further leaka]e was detected on the inboard valve. However, the leakage associated with the outboard valve still was not within acceptable limits. At this point, conversations regarding enforcement discretion began. Adjustments to the seal for PCV-742B cannot be performed without opening the valve or PCV-742A in order to reach the adjustment screws. This is the first instance where leakage requiring seal adjustment has been detected on PCV-7428 during the mid-cycle leak testing. The seals were changed out for all four purge valves during the last refueling outage to provide assurance that seal failure would not occur mid-cycle. Mid-cycle leak testing of these valves has been performed since February 1983 when Amendment 68 to the Technical Specifications was issued. 8712340360 871202 Q-{h7._ hDR ADOCK 050002G5 -il PDR as sa iment v,un taum opponunau uvremee
,_n Mr. R. D. Martin LIC-87-815 Page 2 Amendment 68 also added a requirement that these valves be locked closed unless in a cold or refueling shutdown. The primary reason for this amendment was a concern about the ability of the large 42" butterfly valves to close against a DBA pressure transient. Another reason for this change was to ensure that the valves remain undisturbed and are not subject to seal wear during plant operation. Because the inboard valve has been verified to be leak tight, the containment boundary has been verified to be intact. The Fort Calhoun Station USAR, Appendix G, Criterion 53 requires two containment isolation valves to ensure that a single active failure will not cause an unrestricted release of radioactive material for a DBA. In that the inboard valve is locked shut and leak tight, the intent of Criterion 53 is met. All equipment and personnel needed to perform the seal adjustment are staged. The opening and seal adjustment of the valve is expected to take approximately 20 minutes. The valve will then be closed and retested. If the leakage has not been eliminated, it will be evident from the leak test and readjustment will be undertaken. If the adjustment is successful, the penetration will be pressurized and the surveillance test performed. OPPD is also pursuing an alternative corrective action in the unlikely event that seal adjustment does not correct the leakage to within the acceptance criteria. A blank flange is being constructed which will be installed if leakage is not brought within limits. Every effort will be made to complete this repair within the 48 hour repair time limit of Technical Specification 3.5. However, the preferred fix is to adjust the seals in that it allows the valves to remain fully operational. Therefore, in summary, OPPD requests temporary relief from the requirement of Technical Specification 2.6 to allow opening of PCV-742B to adjust the seal. This relief request is based upon a positive indication that containment integrity is being maintained by PCV-742A. Additionally, it is OPPD's position that going to cold shutdown to effect a two-hour repair exposes the plant to an avoidable thermal cycle. Upon successful adjustment (verified by leak testing), the valve will be returned to, and will remain in, its locked closed configuration as required by Technical Specifications. Thank you for your prompt consideration of this matter. If you have additional questions, do not hesitate to contact us. Sincerely, W h R. L. Antirews Division Manager Nuclear Production RLA:rge
..i. Mr. R. D. Martin LIC-87-815 l Page 3 ] i c: LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Ave., N.W. Washington, DC 20036 A. Bournia, NRC Project Manager P. H. Harrell, Senior NRC Resident Inspector j 1 l i ) 1 l l l l i l ) ) _ - _ _ _ _ _ _ _ _}}