ML17053B512
| ML17053B512 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 03/10/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Rhode G NIAGARA MOHAWK POWER CORP. |
| References | |
| NUDOCS 8003260437 | |
| Download: ML17053B512 (8) | |
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Docket No. 50-410 UNITEDSTATES NUCLEAR REGULATORYCOMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA19406 March 10, 1980 Niagara Mohawk Power Corporation ATTN:
Mr. G.
K.
Rhode Vice President
'ystem Project Management 300 Erie Boulevard, West
- Syracuse, New York 13202 Gentlemen:
The enclosed IE Bulletin No. 80-05, "Vacuum Condition Resulting in Damage to Chemical Volume Control System (CVCS) Holdup Tanks," is forwarded to you for action.
A written response is required. If you desire additional information regarding this matter, please contact this office.
Sincerely, oyce H. Grier
~ector
Enclosures:
l.
List of Recently Issued IE Bulletins CONTACT:
W.
H.
Baunack (215"337-5253) cc w/encls:
Eugene B. Thomas, Jr.,
Esquire 8003 260+3 7
ENCLOSURE 1
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 SSINS No.: 6820 Accession No.:
7912190687 IE Bulletin No. 80-05 Date:
March 10, 1980 Page 1 of 2 VACUUM CONDITION RESULTING IN DAMAGE TO CHEMICAL VOLUME CONTROL SYSTEM (CVCS)
HOLDUP TANKS (SOMETIMES CALLED "CLEAN WASTE RECEIVER TANKS")
In July 1977, IE Circular No. 77-10 identified two instances which resulted in radioactive gaseous releases when tanks at Trojan and Rancho Seco buckled due to partial vacuum conditions.
The Circular "recommended that you examine the systems of your reactor facility(ies) that contain low pressure process or holdup tanks and assure that adequate measures have been taken to protect against vacuum conditions that could result in tank inward buckling and failure with subsequent release of radioactive material or cause other detrimental effects with regard to overall safety of plant operations."
Despite issuance of the Circular, similar events have subsequently occurred at Turkey Point 3 (LER's 78-17, 79-8, and 79-25) and Salem 1 (LER's 79-67 and 79-76).
The accident at TMI has re-emphasized the importance of protecting against unexpected radioactive release paths during abnormal conditions.
The CVCS Holdup Tanks (HUT) represent such a path since normal letdown flow is directed into the CVCS which could add radioactive water to the HUT during abnormal conditions if fuel failures are present.
It is also possible for the same "abnormal conditions" to cause HUT damage, since there is a greater probability of operational errors resulting from the combination of manual and automatic
'aneuvers made to respond to the abnormal condition.
These errors could cause a partial vacuum to be drawn in the HUT, causing tank rupture and a release path that bypasses the normally present reactor vessel and containment barriers to such releases.
We note that both Turkey Point and Salem have elected to install vacuum breakers in their CVCS-HUTS.
As speci.fied by the required Actions below, you should consider installing vacuum protection in your plants, appropriately designed to preclude collapse of the tanks.
Any proposed or already installed vacuum protection system must consider the necessity for precluding adverse effects due to operation or misoperation of the system (for example, creation of an explosive gas mixture if hydrogen gas is present in the HUT).
Any proposed or already installed system must also include consideration of the following:
(a) tanks with a cover gas must be able to admit the cover gas fast enough to keep up with the maximum rate of liquid removal from the tank; (b) vacuum relief valves must be covered by an acceptable surveillance program; (c) tanks that are located outside must have adequate freeze protection for the tank and for the vacuum relief system.
Enclosure 1
IE Bulletin No. 80-05 Date:
March 10, 1980 Page 2 of 2 Actions to be taken by all PWR licensees and permit holders:
1.
Review the design of all systems that contain low pressure or holdup tanks that can be valved to contain primary system water.
Assure that adequate measures have been taken to protect against vacuum conditions that could result in tank damage with the potential for release of radio-active material or detrimental effects with regard to overall safety of plant operations.
2.
Provide a listing of those systems reviewed in Item l.
Describe any measures that already exist for those systems to protect against vacuum conditions, and either:
(1) explain why those measures are adequate in light of the events referenced above, or (2) identify corrective actions taken or planned to provide acceptable protection, and provide a schedule for any planned corrective actions.
Licensees of all operating power reactor facilities shall submit the information requested within 90 days of the date of this letter.
Include in your response to this Bulletin, (a) your schedule for correcting these
- items, (b) if reactor operation is to continue prior to correcting identified deficiencies, include your justification for continued operation.
Licensees with a construction permit shall also submit the design information requested within 90 days of the date of this letter.
Reports shall be submitted to the Director of the appropriate NRC Regional Office and a copy forwarded to the Director, NRC Office of Inspection and Enforcement, Washington, D.C.
20555.
Approved by GAO, 6180225 (R0072):
clearance expires 7-31-80.
Approval was given under a blanket clearance specifically for identified generic problems.
Bulletin No.
Subject ENCLOSURE 2 RECENTLY ISSUED IE BULLETINS Date Issued IE Bulletin No. 80-05 Date March 10, 1980 Page 1 of 1
-Issued To 79-26 Boron Loss From BWR Control Blades 11/20/79 All BWR Power Reactor
'a with an Operating License (OL) 79-27 79-28 Loss of Non-Class-1-E 11/30/79 Instrumentation and Con-trol Power System Bus During Operation Possible Malfunction 12/7/79 of NAMCO Model EA180 Limit. Switches at.
Elevated Temperatures All Power Reactor Facilities with an OL
~
and those nearing Licensing (for Action)
All Power Reactor Facilities with a Construction Permit (CP) (for Informa-tion).
All Power Reactor Facilities with an OL or CP 79-01B
.Environmental guali-fication of Class IE Equipment I/14/80 All Power Reactors with an OL except SEP Plants 80-01 80-02 80-03 80-04 Inadequate guality Assurance for Nuclear Supplied Equipment 1/21/80 Loss of Charcoal From 2/6/80 Standard Type II, 2 Inch, Tray Adsorber Cells Analysis of a PWR Main
,2/8/80
.Steam Line Break with Continued Feedwater Ad-dition Operability of ADS Valve 1/14/80
'neumatic Supply All BWRs with an OL All BWRs with an OL or CP All Power Reactor Facilities with an OL or CP All Power Reactor Facilities with an (OL) or (CP)79-01B Environmental quali-fication of Class IE Equipment 2/29/80 All Power Reactors with an OL except SEP Plants
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